-
ACCF/AHA Practice Guideline
2011 ACCF/AHA Guideline for Coronary Artery BypassGraft
Surgery
A Report of the American College of Cardiology
Foundation/American HeartAssociation Task Force on Practice
Guidelines
Developed in Collaboration With the American Association for
Thoracic Surgery, Society ofCardiovascular Anesthesiologists, and
Society of Thoracic Surgeons
WRITING COMMITTEE MEMBERS*L. David Hillis, MD, FACC, Chair;
Peter K. Smith, MD, FACC, Vice Chair*;
Jeffrey L. Anderson, MD, FACC, FAHA*; John A. Bittl, MD,
FACC;Charles R. Bridges, MD, SCD, FACC, FAHA*; John G. Byrne, MD,
FACC;
Joaquin E. Cigarroa, MD, FACC; Verdi J. DiSesa, MD, FACC;Loren
F. Hiratzka, MD, FACC, FAHA; Adolph M. Hutter, Jr, MD, MACC,
FAHA;
Michael E. Jessen, MD, FACC*; Ellen C. Keeley, MD, MS; Stephen
J. Lahey, MD;Richard A. Lange, MD, FACC, FAHA; Martin J. London,
MD;
Michael J. Mack, MD, FACC*; Manesh R. Patel, MD, FACC; John D.
Puskas, MD, FACC*;Joseph F. Sabik, MD, FACC*#; Ola Selnes, PhD;
David M. Shahian, MD, FACC, FAHA**;
Jeffrey C. Trost, MD, FACC*; Michael D. Winniford, MD, FACC
ACCF/AHA TASK FORCE MEMBERSAlice K. Jacobs, MD, FACC, FAHA,
Chair; Jeffrey L. Anderson, MD, FACC, FAHA, Chair-Elect;
Nancy Albert, PhD, CCNS, CCRN, FAHA; Mark A. Creager, MD, FACC,
FAHA;Steven M. Ettinger, MD, FACC; Robert A. Guyton, MD, FACC;
Jonathan L. Halperin, MD, FACC, FAHA; Judith S. Hochman, MD,
FACC, FAHA;Frederick G. Kushner, MD, FACC, FAHA; E. Magnus Ohman,
MD, FACC;
William Stevenson, MD, FACC, FAHA; Clyde W. Yancy, MD, FACC,
FAHA
*Writing committee members are required to recuse themselves
from voting on sections to which their specific relationship with
industry and otherentities may apply; see Appendix 1 for recusal
information.
ACCF/AHA Representative.ACCF/AHA Task Force on Practice
Guidelines Liaison.Joint Revascularization Section Author.Society
of Cardiovascular Anesthesiologists Representative.American
Association for Thoracic Surgery Representative.#Society of
Thoracic Surgeons Representative.**ACCF/AHA Task Force on
Performance Measures Liaison.This document was approved by the
American Heart Association Science Advisory and Coordinating
Committee in July 2011, and by the American
College of Cardiology Foundation Board of Trustees in July
2011.The American Heart Association requests that this document be
cited as follows: Hillis LD, Smith PK, Anderson JL, Bittl JA,
Bridges CR, Byrne JG,
Cigarroa JE, DiSesa VJ, Hiratzka LF, Hutter AM Jr, Jessen ME,
Keeley EC, Lahey SJ, Lange RA, London MJ, Mack MJ, Patel MR, Puskas
JD, SabikJF, Selnes O, Shahian DM, Trost JC, Winniford MD. 2011
ACCF/AHA guideline for coronary artery bypass graft surgery: a
report of the AmericanCollege of Cardiology Foundation/American
Heart Association Task Force on Practice Guidelines. Circulation.
2011;124:e652e735.
This article has been copublished in the Journal of the American
College of Cardiology.Copies: This document is available on the
World Wide Web sites of the American College of Cardiology
(www.cardiosource.org) and the American
Heart Association (my.americanheart.org). A copy of the document
is available at http://my.americanheart.org/statements by selecting
either the ByTopic link or the By Publication Date link. To
purchase additional reprints, call 843-216-2533 or e-mail
[email protected].
Expert peer review of AHA Scientific Statements is conducted at
the AHA National Center. For more on AHA statements and guidelines
development,visit http://my.americanheart.org/statements and select
the Policies and Development link.
Permissions: Multiple copies, modification, alteration,
enhancement, and/or distribution of this document are not permitted
without the expresspermission of the American Heart Association.
Instructions for obtaining permission are located at
http://www.heart.org/HEARTORG/General/Copyright-Permission-Guidelines_UCM_300404_Article.jsp.
A link to the Copyright Permissions Request Form appears on the
right side of the page.
(Circulation. 2011;124:e652e735.) 2011 by the American College
of Cardiology Foundation and the American Heart Association,
Inc.Circulation is available at http://circ.ahajournals.org DOI:
10.1161/CIR.0b013e31823c074e
e652
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Table of Contents
Preamble . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . .e6541. Introduction . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . .e656
1.1. Methodology and Evidence Review . . . . . . . .e6561.2.
Organization of the Writing Committee . . . . .e6571.3. Document
Review and Approval. . . . . . . . . . .e657
2. Procedural Considerations. . . . . . . . . . . . . . . . . .
. .e6572.1. Intraoperative Considerations . . . . . . . . . . . .
.e657
2.1.1. Anesthetic Considerations:Recommendations. . . . . . . .
. . . . . . . . .e657
2.1.2. Use of CPB . . . . . . . . . . . . . . . . . . . .
.e6592.1.3. Off-Pump CABG Versus Traditional
On-Pump CABG . . . . . . . . . . . . . . . . .e6592.1.4. Bypass
Graft Conduit:
Recommendations. . . . . . . . . . . . . . . . .e6602.1.4.1.
Saphenous Vein Grafts . . . . . .e6612.1.4.2. Internal Mammary
Arteries . . .e6612.1.4.3. Radial, Gastroepiploic, and
Inferior Epigastric Arteries . . .e6612.1.5. Incisions for
Cardiac Access. . . . . . . . .e6612.1.6. Anastomotic Techniques. .
. . . . . . . . . .e6622.1.7. Intraoperative TEE:
Recommendations. . . . . . . . . . . . . . . . .e6622.1.8.
Preconditioning/Management of
Myocardial Ischemia:Recommendations. . . . . . . . . . . . . . .
. .e663
2.2. Clinical Subsets. . . . . . . . . . . . . . . . . . . . . .
. .e6642.2.1. CABG in Patients With Acute MI:
Recommendations. . . . . . . . . . . . . . . . .e6642.2.2.
Life-Threatening Ventricular Arrhythmias:
Recommendations . . . . . . . . . . . . . . . . .e6662.2.3.
Emergency CABG After Failed PCI:
Recommendations. . . . . . . . . . . . . . . . .e6662.2.4. CABG
in Association With Other
Cardiac Procedures:Recommendations. . . . . . . . . . . . . . .
. .e667
3. CAD Revascularization. . . . . . . . . . . . . . . . . . . .
. .e6673.1. Heart Team Approach to Revascularization
Decisions: Recommendations . . . . . . . . . . . . .e6683.2.
Revascularization to Improve Survival:
Recommendations . . . . . . . . . . . . . . . . . . . . .
.e6683.3. Revascularization to Improve Symptoms:
Recommendations . . . . . . . . . . . . . . . . . . . . .
.e6713.4. CABG Versus Contemporaneous Medical
Therapy . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. .e6713.5. PCI Versus Medical Therapy . . . . . . . . . . . .
.e6713.6. CABG Versus PCI . . . . . . . . . . . . . . . . . . . .
.e672
3.6.1. CABG Versus Balloon Angioplasty orBMS . . . . . . . . . .
. . . . . . . . . . . . . . . . .e672
3.6.2. CABG Versus DES . . . . . . . . . . . . . . .e6723.7.
Left Main CAD. . . . . . . . . . . . . . . . . . . . . . .
.e673
3.7.1. CABG or PCI Versus Medical Therapyfor Left Main CAD . . .
. . . . . . . . . . . .e673
3.7.2. Studies Comparing PCI Versus CABGfor Left Main CAD. . . .
. . . . . . . . . . .e673
3.7.3. Revascularization Considerations forLeft Main CAD . . . .
. . . . . . . . . . . . .e674
3.8. Proximal LAD Artery Disease . . . . . . . . . . .e6743.9.
Clinical Factors That May Influence the Choice
of Revascularization . . . . . . . . . . . . . . . . . .
.e6743.9.1. Diabetes Mellitus . . . . . . . . . . . . . . .
.e6743.9.2. Chronic Kidney Disease . . . . . . . . . . .e6753.9.3.
Completeness of
Revascularization . . . . . . . . . . . . . . . .e6753.9.4. LV
Systolic Dysfunction. . . . . . . . . . .e6753.9.5. Previous CABG .
. . . . . . . . . . . . . . . .e6753.9.6. Unstable
Angina/NonST-Elevation
Myocardial Infarction . . . . . . . . . . . . .e6763.9.7. DAPT
Compliance and Stent
Thrombosis: Recommendation . . . . . .e6763.10. TMR as an
Adjunct to CABG. . . . . . . . . . . .e6763.11. Hybrid Coronary
Revascularization:
Recommendations . . . . . . . . . . . . . . . . . . . . .e6764.
Perioperative Management . . . . . . . . . . . . . . . . . .
.e677
4.1. Preoperative Antiplatelet Therapy:Recommendations . . . . .
. . . . . . . . . . . . . . . .e677
4.2. Postoperative Antiplatelet Therapy:Recommendations . . . .
. . . . . . . . . . . . . . . . .e677
4.3. Management of Hyperlipidemia:Recommendations . . . . . . .
. . . . . . . . . . . . . .e6784.3.1. Timing of Statin Use and
CABG
Outcomes . . . . . . . . . . . . . . . . . . . . . .e6794.3.1.1.
Potential Adverse Effects of
Perioperative StatinTherapy . . . . . . . . . . . . . . . .
.e679
4.4. Hormonal Manipulation:Recommendations . . . . . . . . . . .
. . . . . . . . . .e6794.4.1. Glucose Control . . . . . . . . . . .
. . . . . .e6794.4.2. Postmenopausal Hormone
Therapy. . . . . . . . . . . . . . . . . . . . . . . .e6804.4.3.
CABG in Patients With
Hypothyroidism . . . . . . . . . . . . . . . . .e6804.5.
Perioperative Beta Blockers:
Recommendations . . . . . . . . . . . . . . . . . . . .
.e6804.6. ACE Inhibitors/ARBs:
Recommendations . . . . . . . . . . . . . . . . . . . .
.e6814.7. Smoking Cessation: Recommendations . . . . .e6824.8.
Emotional Dysfunction and Psychosocial
Considerations: Recommendation . . . . . . . . .e6834.8.1.
Effects of Mood Disturbance and
Anxiety on CABG Outcomes . . . . . . .e6834.8.2. Interventions
to Treat Depression
in CABG Patients . . . . . . . . . . . . . . . .e6834.9. Cardiac
Rehabilitation:
Recommendation . . . . . . . . . . . . . . . . . . . . .
.e6834.10. Perioperative Monitoring . . . . . . . . . . . . . . .
.e684
Hillis et al 2011 ACCF/AHA CABG Guideline e653
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4.10.1. Electrocardiographic Monitoring:Recommendations . . . .
. . . . . . . . . . .e684
4.10.2. Pulmonary Artery Catheterization:Recommendations . . . .
. . . . . . . . . . .e684
4.10.3. Central Nervous System Monitoring:Recommendations . . .
. . . . . . . . . . . .e684
5. CABG-Associated Morbidity and Mortality:Occurrence and
Prevention . . . . . . . . . . . . . . . . . . .e6855.1. Public
Reporting of Cardiac Surgery
Outcomes: Recommendation . . . . . . . . . . . . . .e6855.1.1.
Use of Outcomes or Volume as
CABG Quality Measures:Recommendations . . . . . . . . . . . . .
. .e686
5.2. Adverse Events . . . . . . . . . . . . . . . . . . . . . .
. .e6875.2.1. Adverse Cerebral Outcomes . . . . . . .e687
5.2.1.1. Stroke . . . . . . . . . . . . . . . . .e6875.2.1.1.1.
Use of Epiaortic Ultra-
sound Imaging to ReduceStroke Rates: Recom-mendation . . . . . .
.e687
5.2.1.1.2. The Role of PreoperativeCarotid Artery Noninva-sive
Screening in CABGPatients: Recommenda-tions . . . . . . . . . .
.e687
5.2.1.2. Delirium . . . . . . . . . . . . . . .e6895.2.1.3.
Postoperative Cognitive
Impairment . . . . . . . . . . . . .e6895.2.2.
Mediastinitis/Perioperative Infection:
Recommendations . . . . . . . . . . . . . . .e6895.2.3. Renal
Dysfunction:
Recommendations . . . . . . . . . . . . . . .e6915.2.4.
Perioperative Myocardial Dysfunction:
Recommendations . . . . . . . . . . . . . . .e6925.2.4.1.
Transfusion:
Recommendation . . . . . . . . .e6925.2.5. Perioperative
Dysrhythmias:
Recommendations . . . . . . . . . . . . . . .e6925.2.6.
Perioperative Bleeding/Transfusion:
Recommendations . . . . . . . . . . . . . . .e6936. Specific
Patient Subsets . . . . . . . . . . . . . . . . . . . . .e694
6.1. Elderly . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . .e6946.2. Women . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . .e6946.3. Patients With Diabetes Mellitus . . . . . . .
. . . .e6956.4. Anomalous Coronary Arteries:
Recommendations . . . . . . . . . . . . . . . . . . . . .
.e6966.5. Patients With Chronic Obstructive Pulmonary
Disease/Respiratory Insufficiency:Recommendations . . . . . . .
. . . . . . . . . . . . . . .e696
6.6. Patients With End-Stage Renal Disease onDialysis:
Recommendations. . . . . . . . . . . . . . .e697
6.7. Patients With Concomitant Valvular Disease:Recommendations
. . . . . . . . . . . . . . . . . . . . . .e697
6.8. Patients With Previous Cardiac Surgery:Recommendation . . .
. . . . . . . . . . . . . . . . . . .e6976.8.1. Indications for
Repeat CABG. . . . . . .e6976.8.2. Operative Risk . . . . . . . . .
. . . . . . . . .e6986.8.3. Long-Term Outcomes . . . . . . . . . .
. . .e698
6.9. Patients With Previous Stroke . . . . . . . . . . .
.e6986.10. Patients With PAD . . . . . . . . . . . . . . . . . . .
.e698
7. Economic Issues . . . . . . . . . . . . . . . . . . . . . . .
. . . .e6987.1. Cost-Effectiveness of CABG and PCI. . . . .
.e698
7.1.1. Cost-Effectiveness of CABGVersus PCI . . . . . . . . . .
. . . . . . . . . . .e699
7.1.2. CABG Versus PCI With DES . . . . . .e6998. Future
Research Directions . . . . . . . . . . . . . . . . . . .e699
8.1. Hybrid CABG/PCI . . . . . . . . . . . . . . . . . . .
.e7008.2. Protein and Gene Therapy. . . . . . . . . . . . . .
.e7008.3. Teaching CABG to the Next Generation:
Use of Surgical Simulators . . . . . . . . . . . . .
.e700References . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . .e701Appendix 1. Author Relationships With Industry
and
Other Entities (Relevant) . . . . . . . . . . . . .e731Appendix
2. Reviewer Relationships With Industry
and Other Entitites (Relevant) . . . . . . . . .e733Appendix 3.
Abbreviation List . . . . . . . . . . . . . . . . . . .e735
PreambleThe medical profession should play a central role in
evaluatingthe evidence related to drugs, devices, and procedures
for thedetection, management, and prevention of disease. When
prop-erly applied, expert analysis of available data on the
benefits andrisks of these therapies and procedures can improve the
qualityof care, optimize patient outcomes, and favorably affect
costs byfocusing resources on the most effective strategies. An
organizedand directed approach to a thorough review of evidence
hasresulted in the production of clinical practice guidelines
thatassist physicians in selecting the best management strategy
foran individual patient. Moreover, clinical practice guidelines
canprovide a foundation for other applications, such as
performancemeasures, appropriate use criteria, and both quality
improvementand clinical decision support tools.
The American College of Cardiology Foundation (ACCF)and the
American Heart Association (AHA) have jointlyproduced guidelines in
the area of cardiovascular diseasesince 1980. The ACCF/AHA Task
Force on Practice Guide-lines (Task Force), charged with
developing, updating, andrevising practice guidelines for
cardiovascular diseases andprocedures, directs and oversees this
effort. Writing commit-tees are charged with regularly reviewing
and evaluating allavailable evidence to develop balanced,
patientcentric recom-mendations for clinical practice.
Experts in the subject under consideration are selected bythe
ACCF and AHA to examine subject-specific data andwrite guidelines
in partnership with representatives fromother medical organizations
and specialty groups. Writingcommittees are asked to perform a
formal literature review;weigh the strength of evidence for or
against particular tests,treatments, or procedures; and include
estimates of expectedoutcomes where such data exist.
Patient-specific modifiers,
e654 Circulation December 6, 2011
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comorbidities, and issues of patient preference that
mayinfluence the choice of tests or therapies are considered.When
available, information from studies on cost is consid-ered, but
data on efficacy and outcomes constitute theprimary basis for the
recommendations contained herein.
In analyzing the data and developing recommendations
andsupporting text, the writing committee uses
evidence-basedmethodologies developed by the Task Force.1 The Class
ofRecommendation (COR) is an estimate of the size of thetreatment
effect considering risks versus benefits in additionto evidence
and/or agreement that a given treatment orprocedure is or is not
useful/effective or in some situationsmay cause harm. The Level of
Evidence (LOE) is an estimateof the certainty or precision of the
treatment effect. The
writing committee reviews and ranks evidence supportingeach
recommendation with the weight of evidence ranked asLOE A, B, or C
according to specific definitions that areincluded in Table 1.
Studies are identified as observational,retrospective, prospective,
or randomized where appropriate.For certain conditions for which
inadequate data are avail-able, recommendations are based on expert
consensus andclinical experience and are ranked as LOE C. When
recommen-dations at LOE C are supported by historical clinical
data,appropriate references (including clinical reviews) are cited
ifavailable. For issues for which sparse data are available, a
surveyof current practice among the clinicians on the writing
commit-tee is the basis for LOE C recommendations, and no
referencesare cited. The schema for COR and LOE is summarized in
Table
Table 1. Applying Classification of Recommendations and Level of
Evidence
A recommendation with Level of Evidence B or C does not imply
that the recommendation is weak. Many important clinical questions
addressed in the guidelinesdo not lend themselves to clinical
trials. Although randomized trials are unavailable, there may be a
very clear clinical consensus that a particular test or therapy
isuseful or effective.
*Data available from clinical trials or registries about the
usefulness/efficacy in different subpopulations, such as sex, age,
history of prior myocardial infarction,history of heart failure,
and prior aspirin use.
For comparative effectiveness recommendations (Class I and IIa;
Level of Evidence A and B only), studies that support the use of
comparator verbs should involvedirect omparisons of the treatments
or strategies being evaluated.
Hillis et al 2011 ACCF/AHA CABG Guideline e655
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1, which also provides suggested phrases for writing
recommen-dations within each COR. A new addition to this
methodology isseparation of the Class III recommendations to
delineate if therecommendation is determined to be of no benefit or
isassociated with harm to the patient. In addition, in view of
theincreasing number of comparative effectiveness studies,
com-parator verbs and suggested phrases for writing
recommenda-tions for the comparative effectiveness of one treatment
orstrategy versus another have been added for COR I and IIa, LOEA
or B only.
In view of the advances in medical therapy across thespectrum of
cardiovascular diseases, the Task Force hasdesignated the term
guideline-directed medical therapy(GDMT) to represent optimal
medical therapy as defined byACCF/AHA guidelinerecommended
therapies (primarilyClass I). This new term, GDMT, will be used
herein andthroughout all future guidelines.
Because the ACCF/AHA practice guidelines address pa-tient
populations (and healthcare providers) residing in NorthAmerica,
drugs that are not currently available in NorthAmerica are
discussed in the text without a specific COR. Forstudies performed
in large numbers of subjects outside NorthAmerica, each writing
committee reviews the potential influ-ence of different practice
patterns and patient populations onthe treatment effect and
relevance to the ACCF/AHA targetpopulation to determine whether the
findings should inform aspecific recommendation.
The ACCF/AHA practice guidelines are intended to
assisthealthcare providers in clinical decision making by
describing arange of generally acceptable approaches to the
diagnosis,management, and prevention of specific diseases or
conditions.The guidelines attempt to define practices that meet the
needs ofmost patients in most circumstances. The ultimate
judgmentregarding the care of a particular patient must be made by
thehealthcare provider and patient in light of all the
circumstancespresented by that patient. As a result, situations may
arise forwhich deviations from these guidelines may be
appropriate.Clinical decision making should involve consideration
of thequality and availability of expertise in the area where care
isprovided. When these guidelines are used as the basis
forregulatory or payer decisions, the goal should be improvement
inquality of care. The Task Force recognizes that situations arise
inwhich additional data are needed to inform patient care
moreeffectively; these areas will be identified within each
respectiveguideline when appropriate.
Prescribed courses of treatment in accordance with
theserecommendations are effective only if followed. Because lackof
patient understanding and adherence may adversely affectoutcomes,
physicians and other healthcare providers shouldmake every effort
to engage the patients active participationin prescribed medical
regimens and lifestyles. In addition,patients should be informed of
the risks, benefits, andalternatives to a particular treatment and
be involved inshared decision making whenever feasible,
particularly forCOR IIa and IIb, where the benefit-to-risk ratio
may be lower.
The Task Force makes every effort to avoid actual,potential, or
perceived conflicts of interest that may arise as aresult of
industry relationships or personal interests amongthe members of
the writing committee. All writing committee
members and peer reviewers of the guideline are required
todisclose all such current relationships, as well as thoseexisting
12 months previously. In December 2009, the ACCFand AHA implemented
a new policy for relationships withindustry and other entities
(RWI) that requires the writingcommittee chair plus a minimum of
50% of the writingcommittee to have no relevant RWI (Appendix 1 for
theACCF/AHA definition of relevance). These statements arereviewed
by the Task Force and all members during eachconference call and
meeting of the writing committee and areupdated as changes occur.
All guideline recommendationsrequire a confidential vote by the
writing committee and mustbe approved by a consensus of the voting
members. Membersare not permitted to write, and must recuse
themselves fromvoting on, any recommendation or section to which
their RWIapply. Members who recused themselves from voting
areindicated in the list of writing committee members, andsection
recusals are noted in Appendix 1. Authors and peerreviewers RWI
pertinent to this guideline are disclosed inAppendixes 1 and 2,
respectively. Additionally, to ensurecomplete transparency, writing
committee members comprehen-sive disclosure informationincluding
RWI not pertinent to thisdocumentis available as an online
supplement. Comprehensivedisclosure information for the Task Force
is also available online
atwww.cardiosource.org/ACC/About-ACC/Leadership/Guidelines-and-Documents-Task-Forces.aspx.
The work of the writing com-mittee was supported exclusively by the
ACCF and AHA withoutcommercial support. Writing committee members
volunteered theirtime for this activity.
In an effort to maintain relevance at the point of care
forpracticing physicians, the Task Force continues to oversee
anongoing process improvement initiative. As a result, inresponse
to pilot projects, evidence tables (with referenceslinked to
abstracts in PubMed) have been added.
In April 2011, the Institute of Medicine released 2
reports:Finding What Works in Health Care: Standards for
SystematicReviews and Clinical Practice Guidelines We Can Trust.2,3
It isnoteworthy that the ACCF/AHA guidelines are cited as
beingcompliant with many of the proposed standards. A
thoroughreview of these reports and of our current methodology is
underway, with further enhancements anticipated.
The recommendations in this guideline are consideredcurrent
until they are superseded by a focused update or thefull-text
guideline is revised. Guidelines are official policy ofboth the
ACCF and AHA.
Alice K. Jacobs, MD, FACC, FAHAChair ACCF/AHA Task Force on
Practice Guidelines
1. Introduction1.1. Methodology and Evidence ReviewWhenever
possible, the recommendations listed in this docu-ment are evidence
based. Articles reviewed in this guidelinerevision covered evidence
from the past 10 years throughJanuary 2011, as well as selected
other references through April2011. Searches were limited to
studies, reviews, and otherevidence conducted in human subjects
that were published inEnglish. Key search words included but were
not limited to thefollowing: analgesia, anastomotic techniques,
antiplatelet
e656 Circulation December 6, 2011
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agents, automated proximal clampless anastomosis
device,asymptomatic ischemia, Cardica C-port, cost effectiveness,
de-pressed left ventricular (LV) function, distal anastomotic
tech-niques, direct proximal anastomosis on aorta, distal
anastomoticdevices, emergency coronary artery bypass graft (CABG)
andST-elevation myocardial infarction (STEMI), heart failure,
in-terrupted sutures, LV systolic dysfunction, magnetic
connectors,PAS-Port automated proximal clampless anastomotic
device,patency, proximal connectors, renal disease, sequential
anasto-mosis, sternotomy, symmetry connector, symptomatic
ischemia,proximal connectors, sequential anastomosis, T grafts,
thoracot-omy, U-clips, Ventrica Magnetic Vascular Port system, Y
grafts.Additionally, the committee reviewed documents related to
thesubject matter previously published by the ACCF and
AHA.References selected and published in this document are
repre-sentative but not all-inclusive.
To provide clinicians with a comprehensive set of data,whenever
deemed appropriate or when published, the absoluterisk difference
and number needed to treat or harm are providedin the guideline,
along with confidence interval (CI) and datarelated to the relative
treatment effects such as odds ratio (OR),relative risk (RR),
hazard ratio (HR), or incidence rate ratio.
The focus of these guidelines is the safe, appropriate,
andefficacious performance of CABG.
1.2. Organization of the Writing CommitteeThe committee was
composed of acknowledged experts inCABG, interventional cardiology,
general cardiology, andcardiovascular anesthesiology. The committee
included rep-resentatives from the ACCF, AHA, American Association
forThoracic Surgery, Society of Cardiovascular Anesthesiolo-gists,
and Society of Thoracic Surgeons (STS).
1.3. Document Review and ApprovalThis document was reviewed by 2
official reviewers, eachnominated by both the ACCF and the AHA, as
well as 1reviewer each from the American Association for
ThoracicSurgery, Society of Cardiovascular Anesthesiologists,
andSTS, as well as members from the ACCF/AHA Task Forceon Data
Standards, ACCF/AHA Task Force on PerformanceMeasures, ACCF
Surgeons Scientific Council, ACCF Inter-ventional Scientific
Council, and Southern Thoracic SurgicalAssociation. All information
on reviewers RWI was distrib-uted to the writing committee and is
published in thisdocument (Appendix 2).
This document was approved for publication by the gov-erning
bodies of the ACCF and the AHA and endorsed by theAmerican
Association for Thoracic Surgery, Society of Car-diovascular
Anesthesiologists, and STS.
2. Procedural Considerations2.1. Intraoperative
Considerations2.1.1. Anesthetic Considerations:
RecommendationsClass I
1. Anesthetic management directed toward early postop-erative
extubation and accelerated recovery of low- tomedium-risk patients
undergoing uncomplicatedCABG is recommended.46 (Level of Evidence:
B)
2. Multidisciplinary efforts are indicated to ensure anoptimal
level of analgesia and patient comfortthroughout the perioperative
period.711 (Level ofEvidence: B)
3. Efforts are recommended to improve interdisciplin-ary
communication and patient safety in the periop-erative environment
(eg, formalized checklist-guidedmultidisciplinary
communication).1215 (Level of Ev-idence: B)
4. A fellowship-trained cardiac anesthesiologist (or
ex-perienced board-certified practitioner) credentialedin the use
of perioperative transesophageal echocar-diography (TEE) is
recommended to provide orsupervise anesthetic care of patients who
are consid-ered to be at high risk.1618 (Level of Evidence: C)
Class IIa1. Volatile anesthetic-based regimens can be useful
in
facilitating early extubation and reducing patientrecall.5,1921
(Level of Evidence: A)
Class IIb1. The effectiveness of high thoracic epidural
anesthe-
sia/analgesia for routine analgesic use is uncer-tain.2225
(Level of Evidence: B)
Class III: HARM1. Cyclooxygenase-2 inhibitors are not
recommended
for pain relief in the postoperative period afterCABG.26,27
(Level of Evidence: B)
2. Routine use of early extubation strategies in facilitieswith
limited backup for airway emergencies oradvanced respiratory
support is potentially harmful.(Level of Evidence: C)
See Online Data Supplement 1 for additional data on anes-thetic
considerations.
Anesthetic management of the CABG patient mandates afavorable
balance of myocardial oxygen supply and demand toprevent or
minimize myocardial injury (Section 2.1.8). Histori-cally, the
popularity of several anesthetic techniques for CABGhas varied on
the basis of their known or potential adversecardiovascular effects
(eg, cardiovascular depression with highdoses of volatile
anesthesia, lack of such depression withhigh-dose opioids, or
coronary vasodilation and concern for asteal phenomenon with
isoflurane) as well as concerns aboutinteractions with preoperative
medications (eg, cardiovasculardepression with beta blockers or
hypotension with angiotensin-converting enzyme [ACE] inhibitors and
angiotensin-receptorblockers [ARBs]2830) (Sections 2.1.8 and 4.5).
Independent ofthese concerns, efforts to improve outcomes and to
reduce costshave led to shorter periods of postoperative mechanical
ventila-tion and even, in some patients, to prompt extubation in
theoperating room (accelerated recovery protocols or
fast-trackmanagement).5,31
High-dose opioid anesthesia with benzodiazepine supple-mentation
was used commonly in CABG patients in theUnited States in the 1970s
and 1980s. Subsequently, itbecame clear that volatile anesthetics
are protective in thesetting of myocardial ischemia and
reperfusion, and this, in
Hillis et al 2011 ACCF/AHA CABG Guideline e657
-
combination with a shift to accelerated recovery or fast-track
strategies, led to their ubiquitous use. As a result,opioids have
been relegated to an adjuvant role.32,33 Despitetheir widespread
use, volatile anesthetics have not beenshown to provide a mortality
rate advantage when comparedwith other intravenous regimens
(Section 2.1.8).
Optimal anesthesia care in CABG patients should include1) a
careful preoperative evaluation and treatment of modifi-able risk
factors; 2) proper handling of all medications givenpreoperatively
(Sections 4.1, 4.3, and 4.5); 3) establishmentof central venous
access and careful cardiovascular monitor-ing; 4) induction of a
state of unconsciousness, analgesia, andimmobility; and 5) a smooth
transition to the early postoper-ative period, with a goal of early
extubation, patient mobili-zation, and hospital discharge.
Attention should be directed atpreventing or minimizing adverse
hemodynamic and hor-monal alterations that may induce myocardial
ischemia orexert a deleterious effect on myocardial metabolism (as
mayoccur during cardiopulmonary bypass [CPB]) (Section 2.1.8).This
requires close interaction between the anesthesiologistand surgeon,
particularly when manipulation of the heart orgreat vessels is
likely to induce hemodynamic instability.During on-pump CABG,
particular care is required duringvascular cannulation and weaning
from CPB; with off-pumpCABG, the hemodynamic alterations often
caused by dis-placement or verticalization of the heart and
application ofstabilizer devices on the epicardium, with resultant
changes inheart rate, cardiac output, and systemic vascular
resistance,should be monitored carefully and managed
appropriately.
In the United States, nearly all patients undergoing CABGreceive
general anesthesia with endotracheal intubation uti-lizing volatile
halogenated general anesthetics with opioidsupplementation.
Intravenous benzodiazepines often aregiven as premedication or for
induction of anesthesia, alongwith other agents such as propofol or
etomidate. Nondepo-larizing neuromuscular-blocking agents,
particularly nonva-golytic agents with intermediate duration of
action, arepreferred to the longer-acting agent, pancuronium. Use
of thelatter is associated with higher intraoperative heart rates
anda higher incidence of residual neuromuscular depression inthe
early postoperative period, with a resultant delay
inextubation.23,34 In addition, low concentrations of
volatileanesthetic usually are administered via the venous
oxygenatorduring CPB, facilitating amnesia and reducing
systemicvascular resistance.
Outside the United States, alternative anesthetic tech-niques,
particularly total intravenous anesthesia via propofoland opioid
infusions with benzodiazepine supplementationwith or without high
thoracic epidural anesthesia, are com-monly used. The use of high
thoracic epidural anesthesiaexerts salutary effects on the coronary
circulation as well asmyocardial and pulmonary function, attenuates
the stressresponse, and provides prolonged postoperative
analge-sia.24,25,35 In the United States, however, concerns about
thepotential for neuraxial bleeding (particularly in the setting
ofheparinization, platelet inhibitors, and CPB-induced
throm-bocytopenia), local anesthetic toxicity, and logistical
issuesrelated to the timing of epidural catheter insertion
andmanagement have resulted in limited use of these tech-
niques.22 Their selective use in patients with severe pulmo-nary
dysfunction (Section 6.5) or chronic pain syndromesmay be
considered. Although meta-analyses of randomizedcontrolled trials
(RCTs) of high thoracic epidural anesthesia/analgesia in CABG
patients (particularly on-pump) haveyielded inconsistent results on
morbidity and mortality rates,it does appear to reduce time to
extubation, pain, andpulmonary complications.3638 Of interest,
although none ofthe RCTs have reported the occurrence of epidural
hematomaor abscess, these entities occur on occasion.38 Finally,
the useof other regional anesthetic approaches for
postoperativeanalgesia, such as parasternal block, has been
reported.39
Over the past decade, early extubation strategies (fast-track
anesthesia) often have been used in low- to medium-risk CABG
patients. These strategies allow a shorter time toextubation, a
decreased length of intensive care unit (ICU)stay, and variable
effects on length of hospital stay.46Immediate extubation in the
operating room, with or withoutmarkedly accelerated postoperative
recovery pathways (eg,ultra-fast-tracking, rapid recovery protocol,
short-stayintensive care) have been used safely, with low rates
ofreintubation and no influence on quality of life.4044
Obser-vational data suggest that physician judgment in
triaginglower-risk patients to early or immediate extubation
workswell, with rates of reintubation1%.45 Certain factors appearto
predict fast-track failure, including previous cardiacsurgery, use
of intra-aortic balloon counterpulsation, andpossibly advanced
patient age.
Provision of adequate perioperative analgesia is importantin
enhancing patient mobilization, preventing pulmonarycomplications,
and improving the patients psychologicalwell-being.9,11 The
intraoperative use of high-dose morphine(40 mg) may offer superior
postoperative pain relief andenhance patient well-being compared
with fentanyl (despitesimilar times to extubation).46
The safety of nonsteroidal anti-inflammatory agents foranalgesia
is controversial, with greater evidence for adversecardiovascular
events with the selective cyclooxygenase-2inhibitors than the
nonselective agents. A 2007 AHA Scien-tific statement presented a
stepped-care approach to themanagement of musculoskeletal pain in
patients with or atrisk for coronary artery disease (CAD), with the
goal oflimiting the use of these agents to patients in whom
safertherapies fail.47 In patients hospitalized with unstable
angina(UA) and nonST-elevation myocardial infarction(NSTEMI), these
agents should be discontinued promptly andreinstituted later
according to the stepped-care approach.48
In the setting of cardiac surgery, nonsteroidal
anti-inflammatory agents previously were used for
perioperativeanalgesia. A meta-analysis of 20 trials of patients
undergoingthoracic or cardiac surgery, which evaluated studies
publishedbefore 2005, reported significant reductions in pain
scores, withno increase in adverse outcomes.49 Subsequently, 2
RCTs, bothstudying the oral cyclooxygenase-2 inhibitor valdecoxib
and itsintravenous prodrug, parecoxib, reported a higher incidence
ofsternal infections in 1 trial and a significant increase in
adversecardiovascular events in the other.26,27 On the basis of the
resultsof these 2 studies (as well as other nonsurgical reports
ofincreased risk with cyclooxygenase-2selective agents), the
U.S.
e658 Circulation December 6, 2011
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Food and Drug Administration in 2005 issued a black boxwarning
for all nonsteroidal anti-inflammatory agents (exceptaspirin)
immediately after CABG.50 The concurrent administra-tion of
ibuprofen with aspirin has been shown to attenuate thelatters
inhibition of platelet aggregation, likely because ofcompetitive
inhibition of cyclooxygenase at the platelet-receptorbinding
site.51
Observational analyses in patients undergoing noncardiacsurgery
have shown a significant reduction in perioperativedeath with the
use of checklists, multidisciplinary surgicalcare, intraoperative
time-outs, postsurgical debriefings, andother communication
strategies.14,15 Such methodology isbeing used increasingly in CABG
patients.1214
In contrast to extensive literature on the role of the surgeon
indetermining outcomes with CABG, limited data on the influenceof
the anesthesiologist are available. Of 2 such reports fromsingle
centers in the 1980s, 1 suggested that the failure to controlheart
rate to110 beats per minute was associated with a highermortality
rate, and the other suggested that increasing duration ofCPB
adversely influenced outcome.52,53 Another observationalanalysis of
data from vascular surgery patients suggested thatanesthetic
specialization was independently associated with areduction in
mortality rate.54
To meet the challenges of providing care for the
increasinglyhigher-risk patients undergoing CABG, efforts have been
di-rected at enhancing the experience of trainees, particularly in
theuse of newer technologies such as TEE. Cardiac
anesthesiolo-gists, in collaboration with cardiologists and
surgeons, haveimplemented national training and certification
processes forpractitioners in the use of perioperative TEE
(Section2.1.7).164,165 Accreditation of cardiothoracic anesthesia
fellow-ship programs from the Accreditation Council for
GraduateMedical Education was initiated in 2004, and efforts are
ongoingto obtain formal subspecialty certification.18
2.1.2. Use of CPBSeveral adverse outcomes have been attributed
to CPB,including 1) neurological deficits (eg, stroke, coma,
postop-erative neurocognitive dysfunction); 2) renal
dysfunction;and 3) the Systemic inflammatory Response
Syndrome(SIRS). The SIRS is manifested as generalized
systemicinflammation occurring after a major morbid event, such
astrauma, infection, or major surgery. It is often
particularlyapparent after on-pump cardiac surgery, during which
surgi-cal trauma, contact of blood with nonphysiological
surfaces(eg, pump tubing, oxygenator surfaces), myocardial
ischemiaand reperfusion, and hypothermia combine to cause a
dra-matic release of cytokines (eg, interleukin [IL] 6 and IL8)
andother mediators of inflammation.55 Some investigators haveused
serum concentrations of S100 beta as a marker of braininjury56 and
have correlated increased serum levels with thenumber of
microemboli exiting the CPB circuit duringCABG. In contrast, others
have noted the increased incidenceof microemboli with on-pump CABG
(relative to off-pumpCABG) but have failed to show a corresponding
worsening ofneurocognitive function 1 week to 6 months
postopera-tively.57,58 Blood retrieved from the operative field
duringon-pump CABG contains lipid material and particulate mat-ter,
which have been implicated as possible causes of post-
operative neurocognitive dysfunction. Although a study59reported
that CPB-associated neurocognitive dysfunction canbe mitigated by
the routine processing of shed blood with acell saver before its
reinfusion, another study60 failed to showsuch an improvement.
It has been suggested that CPB leads to an increasedincidence of
postoperative renal failure requiring dialysis, buta large RCT
comparing on-pump and off-pump CABGshowed no difference in its
occurrence.61 Of interest, thisstudy failed to show a decreased
incidence of postoperativeadverse neurological events (stroke,
coma, or neurocognitivedeficit) in those undergoing off-pump
CABG.
The occurrence of SIRS in patients undergoing CPB hasled to the
development of strategies designed to prevent or tominimize its
occurrence. Many reports have focused on theincreased serum
concentrations of cytokines (eg, IL-2R, IL-6,IL-8, tumor necrosis
factor alpha) and other modulators ofinflammation (eg, P-selectin,
sE-selectin, soluble intercellularadhesion molecule-1, plasma
endothelial cell adhesionmolecule-1, and plasma malondialdehyde),
which reflectleukocyte and platelet activation, in triggering the
onset ofSIRS. A study showed a greater upregulation of
neutrophilCD11b expression (a marker of leukocyte activation)
inpatients who sustained a 50% increase in the serumcreatinine
concentration after CPB, thereby implicating acti-vated neutrophils
in the pathophysiology of SIRS and theoccurrence of post-CPB renal
dysfunction.62 Modulatingneutrophil activation to reduce the
occurrence of SIRS hasbeen investigated; however, the results have
been inconsis-tent. Preoperative intravenous methylprednisolone (10
mg/kg) caused a reduction in the serum concentrations of many
ofthese cytokines after CPB, but this reduction was not associ-ated
with improved hemodynamic variables, diminishedblood loss, less use
of inotropic agents, shorter duration ofventilation, or shorter ICU
length of stay.63 Similarly, the useof intravenous immunoglobulin G
in patients with post-CPBSIRS has not been associated with
decreased rates of short-term morbidity or 28-day mortality.64
Other strategies to mitigate the occurrence of SIRS afterCPB
have been evaluated, including the use of 1) CPBcircuits (including
oxygenators) coated with materials knownto reduce complement and
leukocyte activation; 2) CPBtubing that is covalently bonded to
heparin; and 3) CPBtubing coated with polyethylene oxide polymer or
Poly(2-methoxyethylacrylate). Leukocyte depletion via special-ized
filters in the CPB circuits has been shown to reduce theplasma
concentrations of P-selectin, intercellular adhesionmolecule-1,
IL-8, plasma endothelial cell adhesionmolecule-1, and plasma
malondialdehyde after CPB.65
Finally, closed mini-circuits for CPB have been developed inan
attempt to minimize the bloodair interface and blood contactwith
nonbiological surfaces, both of which promote cytokineelaboration,
but it is uncertain if these maneuvers and techniqueshave a
discernible effect on outcomes after CABG.
2.1.3. Off-Pump CABG Versus Traditional On-Pump CABGSince the
first CABG was performed in the late 1960s, thestandard surgical
approach has included the use of cardiacarrest coupled with CPB
(so-called on-pump CABG), thereby
Hillis et al 2011 ACCF/AHA CABG Guideline e659
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optimizing the conditions for construction of vascular
anas-tomoses to all diseased coronary arteries without
cardiacmotion or hemodynamic compromise. Such on-pump CABGhas
become the gold standard and is performed in about 80%of subjects
undergoing the procedure in the United States.Despite the excellent
results that have been achieved, the useof CPB and the associated
manipulation of the ascendingaorta are linked with certain
perioperative complications,including myonecrosis during aortic
occlusion, cerebrovascu-lar accidents, generalized neurocognitive
dysfunction, renaldysfunction, and SIRS. In an effort to avoid
these complica-tions, off-pump CABG was developed.58,66 Off-pump
CABGis performed on the beating heart with the use of
stabilizingdevices (which minimize cardiac motion); in addition,
itincorporates techniques to minimize myocardial ischemia
andsystemic hemodynamic compromise. As a result, the need forCPB is
obviated. This technique does not necessarily de-crease the need
for manipulation of the ascending aortaduring construction of the
proximal anastomoses.
To date, the results of several RCTs comparing on-pump
andoff-pump CABG in various patient populations have
beenpublished.61,67,68 In addition, registry data and the results
ofmeta-analyses have been used to assess the relative efficacies
ofthe 2 techniques.69,70 In 2005, an AHA Scientific
statementcomparing the 2 techniques concluded that both
proceduresusually result in excellent outcomes and that neither
techniqueshould be considered superior to the other.71 At the same
time,several differences were noted. Off-pump CABG was
associatedwith less bleeding, less renal dysfunction, a shorter
length ofhospital stay, and less neurocognitive dysfunction. The
inci-dence of perioperative stroke was similar with the 2
techniques.On-pump CABG was noted to be less technically complex
andallowed better access to diseased coronary arteries in
certainanatomic locations (eg, those on the lateral LV wall) as
well asbetter long-term graft patency.
In 2009, the results of the largest RCT to date comparingon-pump
CABG to off-pump CABG, the ROOBY (Random-ized On/Off Bypass) trial,
were published, reporting theoutcomes for 2203 patients (99% men)
at 18 Veterans AffairsMedical Centers.61 The primary short-term
endpoint, a com-posite of death or complications (reoperation, new
mechani-cal support, cardiac arrest, coma, stroke, or renal
failure)within 30 days of surgery, occurred with similar
frequency(5.6% for on-pump CABG; 7.0% for off-pump CABG;P0.19). The
primary long-term endpoint, a composite ofdeath from any cause, a
repeat revascularization procedure, ora nonfatal myocardial
infarction (MI) within 1 year ofsurgery, occurred more often in
those undergoing off-pumpCABG (9.9%) than in those having on-pump
CABG (7.4%;P0.04). Neuropsychological outcomes and resource
utiliza-tion were similar between the 2 groups. One year
aftersurgery, graft patency was higher in the on-pump group(87.8%
versus 82.6%; P0.01). In short, the ROOBY inves-tigators failed to
show an advantage of off-pump CABGcompared with on-pump CABG in a
patient populationconsidered to be at low risk. Instead, use of the
on-pumptechnique was associated with better 1-year composite
out-comes and 1-year graft patency rates, with no difference
inneuropsychological outcomes or resource utilization.
Although numerous investigators have used single-center
registries, the STS database, and meta-analyses inan attempt to
identify patient subgroups in whom off-pumpCABG is the preferred
procedure, even these analyses havereached inconsistent conclusions
about off-pump CABGsability to reduce morbidity and mortality
rates.69,72 83 Aretrospective cohort study of 14 766 consecutive
patientsundergoing isolated CABG identified a mortality benefit(OR:
0.45) for off-pump CABG in patients with a pre-dicted risk of
mortality 2.5%,82 but a subsequent ran-domized comparison of
off-pump CABG to traditionalon-pump CABG in 341 high-risk patients
(a Euroscore5) showed no difference in the composite endpoint
ofall-cause death, acute MI, stroke, or a required reinterven-tion
procedure.78 An analysis of data from the New YorkState Cardiac
Surgery Reporting system did not demon-strate a reduction in
mortality rate with off-pump CABG inany patient subgroup, including
the elderly (age 80years) or those with cerebrovascular disease,
azotemia, oran extensively calcified ascending aorta.69
Despite these results, off-pump CABG is the preferredapproach by
some surgeons who have extensive experiencewith it and therefore
are comfortable with its technicalnuances. Recently, published data
suggested that theavoidance of aortic manipulation is the most
importantfactor in reducing the risk of neurological
complica-tions.84,85 Patients with extensive disease of the
ascendingaorta pose a special challenge for on-pump CABG; forthese
patients, cannulation or cross-clamping of the aortamay create an
unacceptably high risk of stroke. In suchindividuals, off-pump CABG
in conjunction with avoid-ance of manipulation of the ascending
aorta (includingplacement of proximal anastomoses) may be
beneficial.Surgeons typically prefer an on-pump strategy in
patientswith hemodynamic compromise because CPB offers sup-port for
the systemic circulation. In the end, most surgeonsconsider either
approach to be reasonable for the majorityof subjects undergoing
CABG.2.1.4. Bypass Graft Conduit: RecommendationsClass I
1. If possible, the left internal mammary artery(LIMA) should be
used to bypass the left anteriordescending (LAD) artery when bypass
of the LADartery is indicated.8689 (Level of Evidence: B)
Class IIa1. The right internal mammary artery (IMA) is prob-
ably indicated to bypass the LAD artery when theLIMA is
unavailable or unsuitable as a bypassconduit. (Level of Evidence:
C)
2. When anatomically and clinically suitable, use of asecond IMA
to graft the left circumflex or rightcoronary artery (when
critically stenosed and per-fusing LV myocardium) is reasonable to
improve thelikelihood of survival and to decrease
reinterven-tion.9094 (Level of Evidence: B)
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Class IIb1. Complete arterial revascularization may be
reason-
able in patients less than or equal to 60 years of agewith few
or no comorbidities. (Level of Evidence: C)
2. Arterial grafting of the right coronary artery may
bereasonable when a critical (>90%) stenosis is
pres-ent.89,93,95 (Level of Evidence: B)
3. Use of a radial artery graft may be reasonable whengrafting
left-sided coronary arteries with severestenoses (>70%) and
right-sided arteries with criti-cal stenoses (>90%) that perfuse
LV myocardi-um.96101 (Level of Evidence: B)
Class III: HARM1. An arterial graft should not be used to bypass
the
right coronary artery with less than a critical steno-sis (
-
hasten postoperative recovery, and 3) enhance cosmesis.
Theutility and benefit of these smaller incisions has been
evidentin subjects undergoing valvular surgery, for which
onlylimited access to the heart is required.
The most minimally invasive access incisions for CABGare seen
with robotically assisted totally endoscopic CABG.A study showed
that totally endoscopic CABG with robotictechnology was associated
with improved physical health,shorter hospital stay, and a more
rapid return to the activitiesof daily living compared with
traditional techniques. Atpresent, direct comparisons of
robotically assisted and con-ventional CABG are lacking.135
The use of minimally invasive cardiac access incisions forCABG
is limited. The need for adequate exposure of theascending aorta
and all surfaces of the heart to accomplishfull revascularization
usually precludes the use of minimalaccess incisions, such as upper
sternotomy, lower sternotomy,or anterolateral thoracotomy.
Nevertheless, use of limitedincisions may increase in the future
with the advent of hybridstrategies that use a direct surgical
approach (usually forgrafting the LAD artery through a small
parasternal incision)and percutaneous coronary intervention (PCI)
of the otherdiseased coronary arteries. The benefit of hybrid
revascular-ization and hybrid operating rooms, in which PCI and
CABGcan be accomplished in one procedure, is yet to be deter-mined.
In patients with certain comorbid conditions, such assevere aortic
calcification, previous chest irradiation, andobesity in
combination with severe diabetes mellitus, fullmedian sternotomy
may be problematic,136 and hybrid revas-cularization may be
preferable.
2.1.6. Anastomotic TechniquesAt present, most coronary bypass
grafts are constructed withhand-sewn suture techniques for the
proximal and distalanastomoses, a practice that has resulted in
good short- andintermediate-term patency rates. Because surgeons
have dif-ferent preferences with regard to the technical aspects of
theprocedure, a wide variety of suture configurations is
used.Sewing of the proximal and distal anastomoses with acontinuous
polypropylene suture is commonly done, buttechniques with
interrupted silk sutures have been used, withsimilar results for
graft patency and adverse events.
Certain clinical scenarios have precipitated an interest
inalternative techniques of constructing coronary bypass
anas-tomoses. Some surgeons and patients wish to avoid thepotential
morbidity and cosmetic results of a median sternot-omy, yet the
least invasive incisions usually are too small toallow hand-sewn
anastomoses. To solve this problem, coro-nary connector devices
have been developed for use witharterial or venous conduits to
enable grafting without directsuturing. In addition, these devices
have been used in subjectswith diseased ascending aortas, in whom a
technique thatallows construction of a proximal anastomosis with
minimalmanipulation of the ascending aorta (typically by
eliminatingthe need for aortic cross-clamping) may result in less
embo-lization of debris, thereby reducing the occurrence of
adverseneurological outcomes. In this situation, the operation
isperformed through a median sternotomy, and the
proximalanastomoses are created with a connector (or may be
hand-
sewn with the assistance of a device that provides a
bloodlessoperative field) without partial or complete clamping of
theascending aorta.
2.1.7. Intraoperative TEE: Recommendations
Class I1. Intraoperative TEE should be performed for evalu-
ation of acute, persistent, and life-threatening hemo-dynamic
disturbances that have not responded totreatment.137,138 (Level of
Evidence: B)
2. Intraoperative TEE should be performed in patientsundergoing
concomitant valvular surgery.137,139(Level of Evidence: B)
Class IIa1. Intraoperative TEE is reasonable for monitoring
of
hemodynamic status, ventricular function, regionalwall motion,
and valvular function in patients un-dergoing CABG.138,140145
(Level of Evidence: B)
The use of intraoperative TEE in patients undergoing
cardiacsurgery has increased steadily since its introduction in the
late1980s. Although its utility is considered to be highest
inpatients undergoing valvular and complex open great-vessel/aortic
surgery, it is commonly used in subjects undergoingCABG. TEE is
most often used,146 although epicardial andepiaortic imaging,
performed under aseptic conditions, allowsvisualization of imaging
planes not possible with TEE.147,148specifically, epiaortic imaging
allows visualization of theblind spot of the ascending aorta
(caused by interposition ofthe trachea with the esophagus), the
site of aortic cannulationfor CPB, from which dislodgement of
friable atheroma, amajor risk factor for perioperative stroke, may
occur (Section5.2.1). In addition, epicardial probes allow imaging
whenTEE is contraindicated, cannot be performed, or
producesinadequate images. It can facilitate the identification
ofintraventricular thrombi when TEE images are equivocal.
The 2003 ACC/AHA/ASE Guideline Update for theClinical
Application of Echocardiography based its recom-mendations on those
reported in the 1996 American Societyof Anesthesiologists/Society
of Cardiovascular Anesthesiol-ogists practice guideline and
considered the use of TEE inCABG patients.149 The latter document
was updated in2010.139 Because of the use of different grading
methodolo-gies in the American Society of Anesthesiologists/Society
ofCardiovascular Anesthesiologists guideline relative to that ofthe
ACCF/AHA, precise comparisons are difficult. However,it is noted
that TEE should be considered in subjectsundergoing CABG, to
confirm and refine the preoperativediagnosis, detect new or
unsuspected pathology, adjust theanesthetic and surgical plan
accordingly, and assess theresults of surgery. The strongest
recommendation is given fortreatment of acute life-threatening
hemodynamic instabilitythat has not responded to conventional
therapies.
Observational cohort analyses and case reports have sug-gested
the utility of TEE for diagnosing acute life-threateninghemodynamic
or surgical problems in CABG patients, manyof which are difficult
or impossible to detect or treat withoutdirect imaging. Evaluation
of ventricular cross-sectional areas
e662 Circulation December 6, 2011
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and ejection fraction (EF) and estimation or direct measure-ment
of cardiac output by TEE may facilitate anesthetic,fluid, and
inotropic/pressor management. The utility of echo-cardiography for
the evaluation of LV end-diastolic area/volume and its potential
superiority over pulmonary arteryocclusion or pulmonary artery
diastolic pressure, particularlyin the early postoperative period,
has been reported150,151(Section 4.10). In subjects without
preoperative transthoracicimaging, intraoperative TEE may provide
useful diagnosticinformation (over and above that detected during
cardiaccatheterization) on valvular function as well as evidence
ofpulmonary hypertension, intracardiac shunts, or other
com-plications that may alter the planned surgery.
In patients undergoing CABG, intraoperative TEE is usedmost
often for the detection of regional wall motion abnor-malities
(possibly caused by myocardial ischemia or infarc-tion) and their
effect on LV function. Observational studieshave suggested that
regional wall motion abnormalities de-tected with TEE can guide
surgical therapy, leading torevision of a failed or inadequate
conduit or the placement ofadditional grafts not originally
planned. The presence of newwall motion abnormalities after CPB
correlates with adverseperioperative and long-term outcomes.143
Although the initial hope that an estimation of coronaryblood
flow with intramyocardial contrast enhancement visu-alized by TEE
would facilitate surgical intervention has notbeen realized,
technical advances in imaging of coronaryarteries and grafts may
ultimately provide reliable informa-tion. At present, the
evaluation of graft flow with conven-tional nonimaging handheld
Doppler probes appears adequate(Section 8). Intraoperative
evaluation of mitral regurgitationmay facilitate detection of
myocardial ischemia and provideguidance about the need for mitral
valve annuloplasty (Sec-tion 6.7). Newer technologies, including
nonimaging methodsfor analyzing systolic and diastolic velocity and
direction andtiming of regional wall motion (Doppler tissue imaging
andspeckle tracking), as well as real-time 3-dimensional im-aging,
may facilitate the diagnosis of myocardial ischemiaand evaluation
of ventricular function. At present, however,their
cost-effectiveness has not been determined, and they aretoo complex
for routine use.152154
Among different centers, the rate of intraoperative TEE usein
CABG patients varies from none to routine; its use isinfluenced by
many factors, such as institutional and practi-tioner preferences,
the healthcare system and reimbursementstrategies, tertiary care
status, and presence of training pro-grams.155 The efficacy of
intraoperative TEE is likely influ-enced by the presence of 1) LV
systolic and diastolicdysfunction, 2) concomitant valvular disease,
3) the plannedsurgical procedure (on pump versus off pump, primary
versusreoperative), 4) the surgical approach (full sternotomy
versuspartial sternotomy versus endoscopic or robotic), 5) its
acuity(elective versus emergency); and 6) physician training
andexperience.137,138,140142,144,145,156163
The safety of intraoperative TEE in patients undergoingcardiac
surgery is uncertain. Retrospective analyses of datafrom patients
undergoing diagnostic upper gastrointestinalendoscopy, nonoperative
diagnostic TEE imaging, and intra-operative imaging by skilled
operators in high-volume cen-
ters demonstrate a low frequency of complications related
toinsertion or manipulation of the probe.164,165 Nevertheless,minor
(primarily pharyngeal injury from probe insertion) andmajor
(esophageal perforation, gastric bleeding, or late me-diastinitis)
complications are reported.166,167 A more indolentcomplication is
that of acquired dysphagia and possibleaspiration postoperatively.
Although retrospective analyses ofpostoperative cardiac surgical
patients with clinically mani-fest esophageal dysfunction have
identified TEE use as a riskfactor,168170 such dysfunction also has
been reported insubjects in whom TEE was not used.171 Advanced
age,prolonged intubation, and neurological injury seem to be
riskfactors for its development. The significance of the
incidentalintraoperative detection and repair of a patent foramen
ovale,a common occurrence, is controversial.172 A 2009
observa-tional analysis of 13 092 patients (25% isolated CABG;
29%CABG or other cardiac procedure), of whom 17% had apatent
foramen ovale detected by TEE (28% of which wererepaired), reported
an increase in postoperative stroke in thepatients who had patent
foramen ovale repair (OR: 2.47; 95%CI: 1.02 to 6.0) with no
improvement in long-termoutcome.173
2.1.8. Preconditioning/Management of MyocardialIschemia:
Recommendations
Class I1. Management targeted at optimizing the determinants
of coronary arterial perfusion (eg, heart rate, diastolicor mean
arterial pressure, and right ventricular or LVend-diastolic
pressure) is recommended to reduce therisk of perioperative
myocardial ischemia and infarc-tion.53,174177 (Level of Evidence:
B)
Class IIa1. Volatile-based anesthesia can be useful in
reducing
the risk of perioperative myocardial ischemia
andinfarction.178181 (Level of Evidence: A)
Class IIb1. The effectiveness of prophylactic
pharmacological
therapies or controlled reperfusion strategies aimedat inducing
preconditioning or attenuating the ad-verse consequences of
myocardial reperfusion injuryor surgically induced systemic
inflammation is un-certain.182189 (Level of Evidence: A)
2. Mechanical preconditioning might be considered toreduce the
risk of perioperative myocardial ischemiaand infarction in patients
undergoing off-pumpCABG.190192 (Level of Evidence: B)
3. Remote ischemic preconditioning strategies using
pe-ripheral-extremity occlusion/reperfusion might be con-sidered to
attenuate the adverse consequences of myo-cardial reperfusion
injury.193195 (Level of Evidence: B)
4. The effectiveness of postconditioning strategies to
at-tenuate the adverse consequences of myocardial reper-fusion
injury is uncertain.196,197 (Level of Evidence: C)
See Online Data Supplements 2 to 4 for additional data
onpreconditioning.
Hillis et al 2011 ACCF/AHA CABG Guideline e663
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Perioperative myocardial injury is associated with
adverseoutcomes after CABG,198200 and available data suggest
adirect correlation between the amount of myonecrosis and
thelikelihood of an adverse outcome198,201204 (Section 5.2.4).
The etiologies of perioperative myocardial ischemia
andinfarction and their complications (electrical or
mechanical)range from alterations in the determinants of global
orregional myocardial oxygen supply and demand to
complexbiochemical and microanatomic, systemic, or vascular
abnor-malities, many of which are not amenable to routine
diagnos-tic and therapeutic interventions. Adequate surgical
reperfu-sion is important in determining outcome, even though it
mayinitially induce reperfusion injury. Various studies
delineat-ing the major mediators of reperfusion injury have
focusedattention on the mitochondrial permeability transition
pore,the opening of which during reperfusion uncouples
oxidativephosphorylation, ultimately leading to cell death.205
Althoughseveral pharmacological interventions targeting
componentsof reperfusion injury have been tried, none has been
found tobe efficacious for this purpose.182,184189,205207
The severity of reperfusion injury is influenced by numer-ous
factors, including 1) the status of the patients
coronarycirculation, 2) the presence of active ongoing ischemia
orinfarction, 3) preexisting medical therapy (Sections 4.3 and4.5),
4) concurrent use of mechanical assistance to improvecoronary
perfusion (ie, intra-aortic balloon counterpulsation),and 5) the
surgical approach used (on pump or off pump).CPB with ischemic
arrest is known to induce the release ofcytokines and chemokines
involved in cellular homeostasis,thrombosis, and coagulation;
oxidative stress; adhesion ofblood cell elements to the
endothelium; and neuroendocrinestress responses; all of these may
contribute to myocardialinjury.208,209 Controlled reperfusion
strategies during CPB,involving prolonged reperfusion with
warm-blood cardiople-gia in conjunction with metabolic enhancers,
are rarely usedin lieu of more routine methods of preservation (eg,
asystolicarrest, anterograde or retrograde blood cardioplegia
duringaortic cross-clamping). Several studies suggest that the
mag-nitude of SIRS is greater with on-pump CABG than withoff-pump
CABG.201,208,210213
Initial studies of preconditioning used mechanical occlusionof
arterial inflow followed by reperfusion via aortic cross-clamping
immediately on institution of bypass or with coronaryartery
occlusion proximal to the planned distal anastomosisduring off-pump
CABG.190,191,214217 Because of concerns of thepotential adverse
cerebral effects of aortic manipulation, enthu-siasm for further
study of this technique in on-pump CABGpatients is limited (Section
5.2.1). Despite intense interest in thephysiology of
postconditioning, few data are available.197 Asmall 2008 study in
patients undergoing valve surgery, whichused repeated manipulation
of the ascending aorta, reported areduction in surrogate markers of
inflammation and myo-necrosis.196 In lieu of techniques utilizing
mechanical occlusion,pharmacological conditioning agents are likely
to be used. Analternative approach that avoids much (but not all)
of the safetyconcerns related to potential vascular injury is
remote precondi-tioning of arterial inflow to the leg or (more
commonly) the armvia blood pressure cuff occlusion.218 Two studies
of patientsundergoing on-pump CABG at a single center, the first of
which
used 2 different myocardial protection strategies and the
secondof which repeated the study with a standardized
cold-bloodcardioplegia routine, reported similar amounts of
troponin re-lease during the 72 hours postoperatively, with no
apparentcomplications.193,195 A larger trial was unable to confirm
anybenefits of a similar protocol, casting doubt on the utility of
thisapproach.194
Volatile halogenated anesthetics and opioids have anti-ischemic
or conditioning properties,32,33,219,220 and propofolhas
antioxidant properties of potential value in subjects
withreperfusion injury.221,222 The salutary properties of
volatileanesthetics during myocardial ischemia are well known.Their
negative inotropic and chronotropic effects are consid-ered to be
beneficial, particularly in the setting of elevatedadrenergic tone
that is common with surgical stimulation.Although contemporary
volatile agents demonstrate somedegree of coronary arterial
vasodilation (with isofluraneconsidered the most potent), the role
of a steal phenomenain the genesis of ischemia is considered to be
trivial.33 Incomparison to propofol/opioid infusions, volatile
agents seemto reduce troponin release, preserve myocardial
function, andimprove resource utilization (ie, ICU or hospital
lengths ofstay) and 1-year outcome.223227 It is postulated that
multiplefactors that influence myocardial preservation modulate
thepotential impact of a specific anesthetic regimen.
Observational analyses have reported an association be-tween
elevated perioperative heart rates and adverse out-comes,228,229
but it is difficult to recommend a specific heartrate for all CABG
patients. Instead, the heart rate may need tobe adjusted up or down
to maintain an adequate cardiacoutput.230,231 Similarly,
controversy exists about managementof blood pressure in the
perioperative period,232 particularlywith regard to systolic
pressure233 and pulse pressure.234Intraoperative hypotension is
considered to be a risk factorfor adverse outcomes in patients
undergoing many types ofsurgery. Unique to CABG are unavoidable
periods of hypo-tension associated with surgical manipulation,
cannulation forCPB, weaning from CPB, or during suspension and
stabili-zation of the heart with off-pump CABG. Minimization ofsuch
periods is desirable but is often difficult to achieve,particularly
in patients who are unstable hemodynamically.
2.2. Clinical Subsets2.2.1. CABG in Patients With Acute MI:
Recommendations
Class I1. Emergency CABG is recommended in patients with
acute MI in whom 1) primary PCI has failed orcannot be
performed, 2) coronary anatomy is suit-able for CABG, and 3)
persistent ischemia of asignificant area of myocardium at rest
and/or hemo-dynamic instability refractory to nonsurgical ther-apy
is present.235239 (Level of Evidence: B)
2. Emergency CABG is recommended in patients un-dergoing
surgical repair of a postinfarction mechan-ical complication of MI,
such as ventricular septalrupture, mitral valve insufficiency
because of papil-lary muscle infarction and/or rupture, or free
wallrupture.240244 (Level of Evidence: B)
e664 Circulation December 6, 2011
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3. Emergency CABG is recommended in patients withcardiogenic
shock and who are suitable for CABGirrespective of the time
interval from MI to onset ofshock and time from MI to
CABG.238,245247 (Level ofEvidence: B)
4. Emergency CABG is recommended in patients
withlife-threatening ventricular arrhythmias (believed tobe
ischemic in origin) in the presence of left mainstenosis greater
than or equal to 50% and/or 3-vesselCAD.248 (Level of Evidence:
C)
Class IIa1. The use of CABG is reasonable as a
revasculariza-
tion strategy in patients with multivessel CAD withrecurrent
angina or MI within the first 48 hours ofSTEMI presentation as an
alternative to a moredelayed strategy.235,237,239,249 (Level of
Evidence: B)
2. Early revascularization with PCI or CABG is rea-sonable for
selected patients greater than 75 years ofage with ST-segment
elevation or left bundle branchblock who are suitable for
revascularization irre-spective of the time interval from MI to
onset ofshock.250254 (Level of Evidence: B)
Class III: HARM1. Emergency CABG should not be performed in
pa-
tients with persistent angina and a small area ofviable
myocardium who are stable hemodynam-ically. (Level of Evidence:
C)
2. Emergency CABG should not be performed in pa-tients with
noreflow (successful epicardial reperfu-sion with unsuccessful
microvascular reperfusion).(Level of Evidence: C)
See Online Data Supplement 5 for additional data on CABGin
patients with acute myocardial infarction.
With the widespread use of fibrinolytic therapy or primaryPCI in
subjects with STEMI, emergency CABG is nowreserved for those with
1) left main and/or 3-vessel CAD, 2)ongoing ischemia after
successful or failed PCI, 3) coronaryanatomy not amenable to PCI,
4) a mechanical complicationof STEMI,241,255,256 and 5) cardiogenic
shock (defined ashypotension [systolic arterial pressure 90 mm Hg
for 30minutes or need for supportive measures to maintain asystolic
pressure 90 mm Hg], evidence of end-organhypoperfusion, cardiac
index 2.2 L/min/m2, and pulmonarycapillary wedge pressure 15 mm
Hg).245,247 In the SHOCK(Should We Emergently Revascularize
Occluded Coronariesfor Cardiogenic Shock) trial, 36% of patients
randomlyassigned to early revascularization therapy underwent
emer-gency CABG.245 Although those who underwent emergencyCABG were
more likely to be diabetic and to have complexcoronary anatomy than
were those who had PCI, the survivalrates of the 2 groups were
similar.247 The outcomes ofhigh-risk STEMI patients with
cardiogenic shock undergoingemergency CABG suggest that CABG may be
preferred toPCI in this patient population when complete
revasculariza-tion cannot be accomplished with PCI.236,238,246
The need for emergency CABG in subjects with STEMI isrelatively
uncommon, ranging from 3.2% to 10.9%.257,258 Ofthe 1572 patients
enrolled in the DANAMI-2 (Danish Mul-ticenter Randomized Study on
Thrombolytic Therapy VersusAcute Coronary Angioplasty in Acute
Myocardial Infarction)study, only 50 (3.2%) underwent CABG within
30 days (30patients initially treated with PCI and 20 given
fibrinolysis),and only 3 patients (0.2%) randomly assigned to
receiveprimary PCI underwent emergency CABG.257 Of the 1100patients
who underwent coronary angiography in the PAMI-2(Primary
Angioplasty in Myocardial Infarction) trial, CABGwas performed
before hospital discharge in 120.258
The in-hospital mortality rate is higher in STEMI
patientsundergoing emergency CABG than in those undergoing it ona
less urgent or a purely elective basis.239,257,259264 In a studyof
1181 patients undergoing CABG, the in-hospital mortalityrate
increased as the patients preoperative status worsened,ranging from
1.2% in those with stable angina to 26% inthose with cardiogenic
shock.265
Although patients requiring emergency or urgent CABGafter STEMI
are at higher risk than those undergoing itelectively, the optimal
timing of CABG after STEMI iscontroversial. A retrospective study
performed before thewidespread availability of fibrinolysis and
primary PCI re-ported an overall in-hospital mortality rate of 5.2%
in 440STEMI patients undergoing CABG as primary reperfusiontherapy.
Those undergoing CABG 6 hours after symptomonset had a lower
in-hospital and long-term (10 years)mortality rate than those
undergoing CABG 6 hours aftersymptom onset.237 Other studies have
provided conflictingresults, because of, at least in part, the lack
of clear delinea-tion between STEMI and NSTEMI patients in these
largedatabase reports.259,265 In an analysis of 9476 patients
hospi-talized with an acute coronary syndrome (ACS) who under-went
CABG during the index hospitalization, 1344 (14%)were STEMI
patients with shock or intra-aortic balloonplacement
preoperatively.264 These individuals had a mortal-ity rate of 4%
when CABG was performed on the thirdhospital day, which was lower
than the mortality ratesreported when CABG was performed earlier or
later duringthe hospitalization.264 In studies in which the data
fromSTEMI patients were analyzed separately with regard to
theoptimal timing of CABG, however, the results appear to
bedifferent. In 1 analysis of 44 365 patients who underwentCABG
after MI (22 984 with STEMI; 21 381 with NSTEMI),the inhospital
mortality rate was similar in the 2 groupsundergoing CABG 6 hours
after diagnosis (12.5% and11.5%, respectively), but it was higher
in STEMI patientsthan in NSTEMI patients when CABG was performed 6
to 23hours after diagnosis (13.6% versus 6.2%; P0.006).262
Thegroups had similar in-hospital mortality rates when CABGwas
performed at all later time points (1 to 7 days, 8 to 14days, and
15 days after the acute event).262 Similarly, in astudy of 138
subjects with STEMI unresponsive to maximalnonsurgical therapy who
underwent emergency CABG, theoverall mortality rate was 8.7%, but
it varied according tothe time interval from symptom onset to time
of operation.The mortality rate was 10.8% for patients undergoing
CABGwithin 6 hours of the onset of symptoms, 23.8% in those
Hillis et al 2011 ACCF/AHA CABG Guideline e665
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undergoing CABG 7 to 24 hours after symptom onset, 6.7%in
patients undergoing CABG from 1 to 3 days, 4.2% in thosewho
underwent surgery from 4 to 7 days, and 2.4% after 8days.266 In an
analysis of data from 150 patients with STEMIwho did not qualify
for primary PCI and required CABG, thein-hospital mortality rate
increased according to the timeinterval between symptom onset and
surgery.239 The mortal-ity rate was 6.1% for subjects who underwent
CABG within6 hours of pain onset, 50% in those who underwent CABG
7to 23 hours after pain onset, and 7.1% in those whounderwent CABG
after 15 days.239 Lastly, in another study,the time interval of 6
hours was also found to be important inSTEMI patients requiring
CABG. The mean time fromsymptom onset to CABG was significantly
shorter in survi-vors versus nonsurvivors (5.12.7 hours versus
11.43.2hours; P0.0007).235 In patients with cardiogenic shock,
thebenefits of early revascularization were apparent across awide
time interval between 1) MI and the onset of shock and2) MI and
CABG. Therefore, although CABG exerts its mostprofound salutary
effect when it is performed as soon aspossible after MI and the
appearance of shock, the timewindow in which it is beneficial is
quite broad.
Apart from the timing of CABG, the outcomes of STEMIpatients
undergoing CABG depend on baseline demographicvariables. Those with
mechanical complications of STEMI(eg, ventricular septal rupture or
mitral regurgitation causedby papillary muscle rupture) have a high
operative mortalityrate.240242,244,255,267 In a study of 641
subjects with ACS, 22with evolving STEMI and 20 with a mechanical
complicationof STEMI were referred for emergency CABG; the
30-daymortality rate was 0% in those with evolving STEMI and25% in
those with a mechanical complication of STEMI.268In those with
mechanical complications, several variableswere predictive of
death, including advanced age, female sex,cardiogenic shock, the
use of intra-aortic balloon counterpul-sation preoperatively,
pulmonary disease, renal insufficiency,and magnitude of elevation
of the serum troponinconcentration.235,239,263,265,266,269,270
2.2.2. Life-Threatening VentricularArrhythmias:
Recommendations
Class I1. CABG is recommended in patients with resuscitated
sudden cardiac death or sustained ventriculartachycardia thought
to be caused by significant CAD(>50% stenosis of left main
coronary artery and/or>70% stenosis of 1, 2, or all 3 epicardial
coronaryarteries) and resultant myocardial
ischemia.248,271,272(Level of Evidence: B)
Class III: HARM1. CABG should not be performed in patients
with
ventricular tachycardia with scar and no evidence ofischemia.
(Level of Evidence: C)
See Online Data Supplement 6 for additional data on
life-threatening ventricular arrhythmias.
Most studies evaluating the benefits of CABG in patientswith
ventricular arrhythmias have examined survivors of
out-of-hospital cardiac arrest as well as patients with
induc-ible ventricular tachycardia or fibrillation during
electro-physiological study.272274 In general, CABG has been
moreeffective in reducing the occurrence of ventricular
fibrillationthan of ventricular tachycardia, because the mechanism
of thelatter is usually reentry with scarred endocardium rather
thanischemia. Observational studies have demonstrated a favor-able
prognosis of subjects undergoing CABG for ischemicventricular
tachycardia/fibrillation.248
In survivors of cardiac arrest who have severe but operableCAD,
CABG can suppress the appearance of arrhythmias,reduce subsequent
episodes of cardiac arrest, and result in agood long-term
outcome.271273 It is particularly effectivewhen an ischemic cause
of the arrhythmia can be documented(for instance, when it occurs
with exercise).275 Still, becauseCABG may not alleviate all the
factors that predispose toventricular arrhythmias, concomitant
insertion of an implant-able cardioverter-defibrillator is often
warranted.276 Simi-larly, continued inducibility or clinical
recurrence of ventric-ular tachycardia after CABG usually requires
an implantablecardioverter-defibrillator implantation.
Patients with depressed LV systolic function, advancedage,
female sex, and increased CPB time are at higher risk
forlife-threatening arrhythmias in the early postoperative
period.Given the poor short-term prognosis of those with
thesearrhythmias, mechanical and ischemic causes should
beconsidered in the postoperative setting.277279
2.2.3. Emergency CABG After Failed PCI: RecommendationsClass
I
1. Emergency CABG is recommended after failed PCIin the presence
of ongoing ischemia or threatenedocclusion with substantial
myocardium at risk.280,281(Level of Evidence: B)
2. Emergency CABG is recommended after failed PCIfor hemodynamic
compromise in patients withoutimpairment of the coagulation system
and without aprevious sternotomy.280,282,283 (Level of Evidence:
B)
Class IIa1. Emergency CABG is reasonable after failed PCI
for
retrieval of a foreign body (most likely a fracturedguidewire or
stent) in a crucial anatomic location.(Level of Evidence: C)
2. Emergency CABG can be beneficial after failed PCIfor
hemodynamic compromise in patients with im-pairment of the
coagulation system and withoutprevious sternotomy. (Level of
Evidence: C)
Class IIb1. Emergency CABG might be considered after failed
PCI for hemodynamic compromise in patients withprevious
sternotomy. (Level of Evidence: C)
Class III: HARM1. Emergency CABG should not be performed
after
failed PCI in the absence of ischemia or threatenedocclusion.
(Level of Evidence: C)
e666 Circulation December 6, 2011
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2. Emergency CABG should not be performed afterfailed PCI if
revascularization is impossible becauseof target anatomy or a
no-reflow state. (Level ofEvidence: C)
See Online Data Supplement 7 for additional data on CABGafter
failed PCI.
With widespread stent use as well as effective antiplate-let and
antithrombotic therapies, emergency CABG afterfailed PCI is not
commonly performed. In a 2009 analysisof data from almost 22 000
patients undergoing PCI at asingle center, only 90 (0.4%) required
CABG within 24hours of PCI.281 A similarly low rate (0.8%) of
emer-gency CABG after PCI has been reported by others.284 286The
indications for emergency CABG after PCI include 1)acute (or
threatened) vessel closure, 2) coronary arterialdissection, 3)
coronary arterial perforation,281 and 4) mal-function of PCI
equipment (eg, stent dislodgement, frac-tured guidewire). Subjects
most likely to require emer-gency CABG after failed PCI are those
with evolvingSTEMI, cardiogenic shock, 3-vessel CAD, or the
presenceof a type C coronary arterial lesion (defined as 2 cm
inlength, an excessively tortuous proximal segment, anextremely
angulated segment, a total occlusion 3 monthsin duration, or a
degenerated SVG that appears to befriable).281
In those in whom emergency CABG for failed PCI isperformed,
morbidity and mortality rates are increased com-pared with those
undergoing elective CABG,287289 resultingat least in part from the
advanced age of many patients nowreferred for PCI, some of whom
have multiple comorbidconditions and complex coronary anatomy.
Several variableshave been shown to be associated with increased
periop-erative morbidity and mortality rates, including 1)
de-pressed LV systolic function,290 2) recent ACS,290,291
3)multivessel CAD and complex lesion morphology,291,292
4)cardiogenic shock,281 5) advanced patient age,293 6) ab-sence of
angiographic collaterals,293 7) previous PCI,294and 8) a prolonged
time delay in transfer to the operatingroom.293 In patients
undergoing emergency CABG forfailed PCI, an off-pump procedure may
be associated witha reduced incidence of renal failure, need for
intra-aorticballoon use, and reoperation for bleeding.283,295
If complete revascularization is achieved with minimaldelay in
patients undergoing emergency CABG after failedPCI, long-term
prognosis is similar to that of subjectsundergoing elective
CABG.280,282,296 In-hospital morbidityand mortality rates in
women297 and the elderly298 undergoingemergency CABG for failed PCI
are relatively high, but thelong-term outcomes in these individuals
are comparable tothose achieved in men and younger patients.
2.2.4. CABG in Association With Other CardiacProcedures:
Recommendations
Class I1. CABG is recommended in patients undergoing non-
coronary cardiac surgery with greater than or equalto 50%
luminal diameter narrowing of the left maincoronary artery or
greater than or equal to 70%
luminal diameter narrowing of other major coro-nary arteries.
(Level of Evidence: C)
Class IIa1. The use of the LIMA is reasonable to bypass a
signifi-
cantly narrowed LAD artery in patients undergoingnoncoronary
cardiac surgery. (Level of Evidence: C)
2. CABG of moderately diseased coronary arteries(>50% luminal
diameter narrowing) is reasonablein patients undergoing noncoronary
cardiac sur-gery. (Level of Evidence: C)
3. CAD RevascularizationRecommendations and text in this section
are the result ofextensive collaborative discussions between the
PCI andCABG writing committees, as well as key members of theStable
Ischemic Heart Disease (SIHD) and UA/NSTEMIwriting committees.
Certain issues, such as older versus morecontemporary studies,
primary analyses versus subgroupanalyses, and prospective versus
post hoc analyses, have beencarefully weighed in designating COR
and LOE; they areaddressed in the appropriate corresponding text.
The goals ofrevascularization for patients with CAD are to 1) to
improvesurvival and 2) to relieve symptoms.
Revascularization recommendations in this section
arepredominantly based on studies of patients with symptomaticSIHD
and should be interpreted in this context. As discussedlater in
this section, recommendations on the type of revas-cularization
are, in general, applicable to patients with UA/NSTEMI. In some
cases (eg, unprotected left main CAD),specific recommendations are
made for patients with UA/NSTEMI or STEMI.
Historically, most studies of revascularization have beenbased
on and reported according to angiographic criteria.Most studies
have defined a significant stenosis as 70%diameter narrowing;
therefore, for revascularization decisionsand recommendations in
this section, a significant stenosishas been defined as 70%
diameter narrowing (50% forleft main CAD). Physiological criteria,
such as an assessmentof fractional flow reserve, has been used in
deciding whenrevascularization is indicated. Thus, for
recommendations onrevascularization in this section, coronary
stenoses withfractional flow reserve 0.80 can also be
consideredsignificant.299,300
As noted, the revascularization recommendations havebeen
formulated to address issues related to 1) improvedsurvival and/or
2) improved symptoms. When one method ofrevascularization is
preferred over the other for improvedsurvival, this consideration,
in general, takes precedence overimproved symptoms. When discussing
options for revascu-larization with the patient, he or she should
understand whenthe procedure is being performed in an attempt to
improvesymptoms, survival, or both.
Although some results from the SYNTAX (Synergybetween
Percutaneous Coronary Intervention with TAXUSand Cardiac Surgery)
study are best characterized assubgroup analyses and hypothesis
generating, SYNTAXnonetheless represents the latest and most
comprehensivecomparison of contemporary PCI and CABG.301,302
There-
Hillis et al 2011 ACCF/AHA CABG Guideline e667
-
fore, the results of SYNTAX have been considered appro-priately
when formulating our revascularization recom-mendations. Although
the limitations of using theSYNTAX score for certain
revascularization recommenda-tions are recognized, the SYNTAX score
is a reasonablesurrogate for the extent of CAD and its complexity
andserves as important information that should be consideredwhen
making revascularization decisions. Recommenda-tions that refer to
SYNTAX scores use them as surrogatesfor the extent and complexity
of CAD.
Revascularization recommendations to improve survivaland
symptoms are given in the following text and summa-rized in Tables
2 and 3. References to studies comparingrevascularization with
medical therapy are presented whenavailable for each anatomic
subgroup.
See Online Data Supplements 8 and 9 for additional dataregarding
the survival and symptomatic benefits with CABGor PCI for different
anatomic subsets.
3.1. Heart Team Approach to RevascularizationDecisions:
Recommendations
Class I1. A Heart Team approach to revascularization is
recommended in patients with unprotected left mainor complex
CAD.302304 (Level of Evidence: C)
Class IIa1. Calculation of the STS and SYNTAX scores is
reasonable in patients with unprotected left mainand complex
CAD.301,30