Aortic Diseases

Aortic Diseases

Elliot L. Chaikof, MD, PhDRoberta and Stephen R. Weiner Department of Surgery

Beth Israel Deaconess Medical Center Harvard Medical School

Elliot L. Chaikof, MD, PhD David C. Brewster, MDRonald L. Dalman, MDMichel S. Makaroun, MDKarl A. Illig, MDGregorio A. Sicard, MDCarlos H. Timaran, MD Gilbert R. Upchurch, Jr., MD Frank J. Veith, MD

Clinical Practice Council of the SVS

AAA Practice Guidelines Writing

Committee

Prevalence of Aortic Aneurysm

• Prevalence of AAA among women is slowly increasing, with women now representing 1/3 of patients presenting with rupture.

Circulation 2011; 124:1118-1123

AAA (> 3 cm) in 1.7% of 26,000 65 y/o men screened

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

1993 1995 1997 1999 2001 2003 2005

EVAR

TOTAL OPEN

Annual Open AAA and EVAR in US: 1993 - 2005

Schermerhorn M et al. JVS 2009; 49(3):543-50

Lancet 2002; 360: 1531–39

Community-based screening reduces mortality from an AAA in men aged 65–79 years, but are not cost effective in women in whom the prevalence of AAAs is lower

Jonk YC, Kane RL, Lederle FA, MacDonald R, Cutting AH, Wilt TJ.Int J Technol Assess Health Care 2007;23:205-15.

All Markov modeling studies published to date have predicted higher lifetime costs associated with EVAR

SVS Clinical Decisions for Patients with Aortic Disease

1. Comparative effectiveness of OR vs EVAR• Ascending and arch aortic aneurysms• Thoracoabdominal aneurysms• Acute or Chronic Type B aortic dissections

2. Optimal treatment of AAA between 5 – 6 cm

3. Optimal surveillance regimens after EVAR

$7,300 per capita in US in 2008Bending the cost curve

Reduce Per Capita Costs

Reduce Unnecessary Interventions

• Selective screening and surveillance• Selective repair• Reducing costs for EVAR or OSR

Screening Abdominal Aortic Aneurysms Very Efficiently (SAAAVE) Act 2006

• A one-time AAA US screening as part of a Welcome to Medicare physical exam.

• The physical must be conducted during the first 12 months of enrollment.

Who qualifies for the Medicare screening? • Men who have smoked sometime during their life• Men and women with a family history of AAA

In 2009, 20,000 Medicare patients were screened out of 200,000 in the US at risk

Risk Factors for Aortic Aneurysms• Smoking is the single strongest risk

factor for the development of AAA• AAA risk increases by 40% every 5

years after the age of 65 years • Men are at much higher risk of AAA

than women• Central obesity increases risk• A family history of AAA doubles the

risk of AAA

Risk factors for aortic aneurysms do not correlate with many risk factors for atherosclerosis -

• Hypertension is weakly associated with AAA

• The relationship between hyperlipidemia and AAA is complex

• Diabetes is protective of AAA formation

Nat. Genet. 40, 217–224 (2008)

Nat. Genet. 42, 692–697 (2010)

Who do we screen?

Ann Intern Med. 2005;142:203-211

J Vasc Surg 2005;41:741-51

British Medical J 2004; 329: 1259-1262

• Selective screening of high risk groups

• Risk factor scores

Who should be enrolled in continued AAA

SurveillanceShould we follow aneurysms less than 4 cm in diameter given their low risk of rupture?

• 12 yr analysis of 1121 AAA in 65 yr-old men • 2.6 cm < AAA < 2.9 cm

• 14% > 5.4 cm at 10 years

• 3.5 cm < AAA < 3.9 cm • 10.5% > 5.4 cm and 1.4% had

ruptured at 2 years

Br J Surg 90: 821-6, 2003

Biomarkers for AAA Disease

Has the balance of risk and benefit changed with EVAR?

Immediate EVAR vs. Surveillance4.0 cm < AAA < 5.4 cm

Management of the Small AAA

360 patients

180 pts EVAR 180 pts SurveillanceMean f/u 26 mos.

236 pts EVAR 15 pts OSR 102 pts Surv.

• Aneurysm-related mortality (0.6% vs 0.6%; p=1)

• 30-day mortality (1% vs 0%; p=1)

• Aneurysm rupture (0% vs 0.2%; p=0.2)

CAESAR Small AAA Trial: Immediate EVAR vs. Surveillance

• 76/180 (42%) patients in the surveillance group underwent repair

• The probability of receiving AAA repair over a 3-yr study interval was

• > 50% > 4.5 cm

• 32/180 (18%) underwent open surgery because of loss of EVAR suitability

CAESAR Trial at 3 Years: Immediate EVAR vs. Surveillance

Crossover Effect in Trials of AAA Treatment vs

Observation• UK SAT: 62% (327/527) crossed

over during a 5-year follow-up period.

• ADAM: 62% (351/567) crossed over during a 5-year follow-up period.

• Crossovers related to subjective ‘symptoms’ or patient preference.

Patient Perspective with a Small AAAThe question is not…

“if” EVAR should be performed but “when”…

Pharmacological Strategies to Prevent AAA Expansion or Rupture• b-blockers and ACE inhibitors• Tetracycline and macrolide antibiotics• Anti-platelet agents• Statins

J Vasc Surg 2002; 36: 1-12

The Non-Invasive Treatment of Abdominal Aortic Aneurysm Clinical Trial (N-TA3CT)NIH Funded Trial - Randomize 248 patients

Determine if doxycycline (100 mg bid) will inhibit by 40% the increase in diameter of small AAA (3.5-5.0 cm in men, 3.5-4.5 cm in women) over a 24-month period.

Clinical Trials to Assess Risk and the Benefit of Medical Intervention

• Inflammation and Risk Prediction in Patients With AAA (Vanderbilt, PI: U. Sampson )– predicting risk using FDG-PET with CT

• Study on Anti-inflammatory Effect of Anti-hypertensive Treatment in Patients With Small AAA's and Mild Hypertension (VU University, PI: Jan D. Blankensteijn)– Aliskiren and Amlodipine

• Evaluation of Effect of ACE Inhibitors (perindopril) on Small Aneurysm Growth Rate – (Imperial College, PI: Neil R Poulter)

• Feasibility Study of Exercise Training for AAA Disease – (Sheffield Teaching Hospitals/University

of Hull)

Clinical Trials to Assess Risk and the Benefit of Medical Intervention

Morbidity of Open and EVAR AAA Repairs: 1995 - 2008

Schermerhorn M et al. NEJM 2008; 358:464-474.

• Risk models that incorporate physiological and anatomical data (APACHE II, GAS, POSSUM).

• Improved tools to assess likelihood of aneurysm expansion and rupture risk among high risk patients.

• Interventions to reduce postoperative morbidity (e.g. cardiac, pulmonary, renal)

Risk Models for Elective EVAR or Open AAA Repair

N Engl J Med 2007;357:2277-84

Number of CT scans/yr in US

Lifetime Cancer Risk/Abdominal CTDoubling in less than a decade

J Vasc Surg 2009;49:60-5

• 406 paired CT/US examinations• Sensitivity for Duplex ultrasound was 86%• All clinically significant endoleaks demonstrated

on CTA were also detected on Duplex ultrasound

• Contrast Ultrasound in the Surveillance of EVAR (n = 160)– Ottawa Hospital Research Institute, PI:

Sudhir Nagpal

• CT Versus Color Duplex US for Surveillance of EVAR. A Prospective Multicenter Study (n = 1000)– Centre Hospitalier Universitaire de Nice,

PI: Hassen-Khofja Reda

US vs CTA for Surveillance After EVAR