Infective Endocarditis

Infective EndocarditisInfective Endocarditis

October 11, 2005

Dr. Kanagala

Microbiology: Organisms Microbiology: Organisms ResponsibleResponsible

Bacteria are the predominant causeFungiRickettsiaChlamydiaMicroorganisms vary dependent on risk

factors predisposing patient to IEStaph Aureus= single most common cause

Native Valve EndocarditisNative Valve Endocarditis

Streptococcus responsible for more than 50% of cases

StaphylococciEnterococciInfection occurs most frequently in those

with preexisting valvular abnormality

StaphylococciStaphylococci

Causes endocarditis in those with normal and abnormal valves

Most are coagulase positive S.AureusCauses destruction of valves, multiple distal

abscesses, myocardial abscesses, conduction defects, and pericarditis

EnterococciEnterococci

Patients generally have underlying valvular disease

May occur following manipulation of genitourinary or lower gastrointestinal tract

Remainder of cases caused by Haemphilus Actinobacillus, Cardiobacterium, Eikenella, Kingella, Bartonella, or Coxiella Burnetti

DiagnosisDiagnosis

Negative culture can occur in 5% of patients.

1/3 to ½ are negative due to prior antibiotic use

In patients with culture negative IE, advise lab to allow specialized testing to recover the causative organism which is needed to adequately treat

IDU associated IEIDU associated IE

Skin flora and contaminated injection devices are the most frequent sources involved in IDU-associated IE

S. Aureus – Most common (50% of cases) Streptococcal species Gram negative Bacilli

– Pseudomonas– Serratia species

Fungi– Candida

Prosthetic Valve EndocarditisProsthetic Valve Endocarditis

Most commonly occur during the perioperative period S. epidermidis

– Most frequently isolated organism Early PVE (w/i 60 days of surgery)

– Assoc. with valve dysfunction and fulminant clinical course Late PVE (beyond 60 days postop)

– Disease course is less fulminant Mycotic PVE (Aspergillus and Candida)

– Larger vegetations

Clinical FeaturesClinical Features

Acute IE – Rapid onset of high fevers and rigors with hemodynamic deterioration and death within days to weeks if not treated– Assoc. with highly virulent organisms such as Staph

Aureus Subacute IE – Indolent course with progressive

constitutional signs and symptoms and gradual deterioration– Assoc. with avirulent organisms such as viridans

streptococci

Clinical FeaturesClinical Features

Bacteremia can produce signs and symptoms that are often nonspecific usually within 2 weeks of infection– Most common course of disease (fevers, chills, nausea,

vomiting, fatigue and malaise)– Fever is the most common symptom – Fever can be absent in pts with antibiotic use,

antipyretic use, severe CHF, or renal failure Prosthetic valve patient with a fever requires IE

work up

Cardiac Clinical FeaturesCardiac Clinical Features

Heart murmurs are present in up to 85% of cases of IE.– Most commonly regurgitant lesions secondary to valvular

destruction Acute or progressive CHF is the leading cause of death

in patients with IE (70% of patients)– Distortion or perforation of valvular leaflets– Rupture of the chordae tendinae or papillary muscles– Perforation of the cardiac chambers (rare)

Valvular abscesses and Pericarditis Heart blocks and Arrhythmias

Embolic Clinical FeaturesEmbolic Clinical Features

Extracardiac manifestations are the result of arterial embolization of fragments of the friable vegetation– CNS complications occur in 20-40% of cases (embolic stroke with

MCA affected most frequently)– Retinal artery emboli may cause monocular blindness– Mycotic aneurysm may cause a SAH– IVDU can cause right sided lesions (tricuspid valve) – Pulmonary

complications– Pulmonary complications ( pulmonary infarction, pneumonia,

empyema, or pleural effusion)– Coronary artery emboli (Acute MI or myocarditis with arrhythmias)– Splenic infarction (LUQ abdominal pain)– Renal emboli (flank pain or hematuria)

Clinical FeaturesClinical Features

Persistent bacteremia can stimulate the humoral and cellular immune systems resulting in circulating immune complexes

Petechiae – Red, nonblanching lesions that become brown after several days (20-40%)– Conjunctivae, buccal mucosa, and extremities

Splinter hemorrhages – Linear dark streaks under the fingernails (15%)

Osler’s nodes – Small tender subcutaneous nodules that develop on the pads of the fingers or toes (25%)

Janeway lesions – Small hemorrhagic painless plaques located on the palms or soles

Roth spots – Oval retinal hemorrhages with pale centers located near the optic disc

DiagnosisDiagnosis

Diagnosis of IE requires hospitalization– Cultures– Echocardiogram– Clinical observation

Duke Criteria – 90% sensitive– Major Criteria– Minor Criteria

Major CriteriaMajor Criteria

Positive blood culture for:– Strep bovis, Strep viridans, or HACEK group– Staph aureus or Enterococci– Microorganisms c/w IE from persistent positive

blood cultures 2 positive blood cultures drawn >12 hrs apart All of 3 or a majority of 4 or more positive blood

cultures

Major CriteriaMajor Criteria

Echocardiographic involvement:– Mass on valve– Abscess– Dehiscence of prosthetic valve– New valvular regurgitation

Minor CriteriaMinor Criteria

Predisposition: Heart condition or injection drug use

Fever > 38 degrees C Vascular: Emboli, conjunctival hemorrhages,

janeway lesions Immunological: Glomerulonephritis, osler’s

nodes, roth spots, and rheumatoid fever Positive blood cultures Echocardiographic findings c/w IE

Duke CriteriaDuke Criteria

Definite infective endocarditis– Microorganisms demonstrated by culture or histologic examination of

vegetation or emboli– Abscess with active endocarditis– Two major criteria– One major and three minor criteria– Five minor criteria

Possible endocarditis– Findings c/w IE that fall short of definite, but not rejected

Rejected– Firm alternate diagnosis– Resolution of manifestations of IE with abx for < 4 days– No pathologic evidence of IE at surgery or autopsy after 4 days of abx

DDx and Consideration of IEDDx and Consideration of IE

IE should be considered in:– All febrile IDUs– Pts with a cardiac prosthesis and fever (or

malaise, vasculitis or new murmur)– Pts with new murmur or change in murmur

with evidence of vasculitis or embolization– Any cardiac risk factor with unexplained fever– Any patient with a prolonged fever (>2 weeks)

Evaluation of BacteremiaEvaluation of Bacteremia

All patients with suspected bacteremia should have blood cultures drawn in the ED prior to abx

Blood cultures should be drawn in 3 different sites

Minimum of 10 ml blood in each bottleMinimum of one hour between first and last

bottle

Diagnostic TestsDiagnostic Tests

ECG should be done in all pts with suspected IE– Nonspecific usually– Conduction abnormalities ( new LBBB, Prolonged PR

interval, new RBBB, complete heart block)– Junctional tachycardia

Chest Xray– Pulmonic emboli or CHF

Nonspecific lab tests– Anemia (70-90% of cases)– Elevated ESR (>90% of cases)– Hematuria

EchocardiographyEchocardiography

Mandatory in all pts with possible IE Transthoracic Echo(TTE) should be done first.

– Specificity for vegetations is 98%– Sensitivity varies but it is the highest with IDUs because they

more often have larger vegetations, right sided valvular lesions and favorable precordial windows.

Transesophageal Echo(TEE) has a higher sensitivity and specificity than TTE– Recommended for the following:

Prosthetic valves Pts with obesity, chest wall deformities, COPD Intermediate or high probability of IE

TreatmentTreatment

Initial Stabilization– Rapid airway stabilization secondary to possible

respiratory or hemodynamic compromise( acidosis, altered mental status, sepsis)

– Cardiac decompensation may occur secondary to left sided valvular rupture

Intraaortic balloon counterpulsation may be indicated

– Neurologic complications such as stroke Standard stroke protocol

Empiric TreatmentEmpiric Treatment

Therapy of suspected Bacterial Endocarditis– Uncomplicated history

Ceftriaxone or nafcillin plus gentamycin

– IVDU, Congenital heart disease, MRSA, current abx use

Nafcillin plus gentamycin plus vancomycin

– Prosthetic heart valve Vancomycin plus gentamycin plus rifampin

Most patients will require 4 to 6 weeks of antibiotic therapy

Surgical TreatmentSurgical Treatment

Indications for surgical management:– Severe valvular dysfunction: Acute CHF or

impaired hemodynamic status– Relapsing prosthetic valve endocarditis– Major embolic complications– Fungal endocarditis– New conduction defects or arrhythmias– Persistent bacteremia

AnticoagulationAnticoagulation

Anticoagulation for native valve endocarditis has not been shown to be beneficial– Increase the risk of intracranial hemorrhage

Pts with prosthetic valves who are treated with anticoagulation can be maintained on their regimen with proper caution for CNS complications

IE ProphylaxisIE Prophylaxis

Prophylaxis is indicated for:– Prosthetic heart valves– Congenital cardiac manifestations– Acquired valvular dysfunction– Hypertrophic cardiomyopathy– Mitral valve prolapse with documented regurgitation– History of endocarditis

Not indicated for the following:– MVP without regurgitation– Pacemakers– Physiologic murmurs– Prior CABG, angioplasty, ASD repair, VSD, or PDA

IE ProphylaxisIE Prophylaxis

Dental, oral, respiratory or esophageal procedures– Amoxicillin or Ampicillin or Clindamycin

Genitourinary, gastrointestinal procedures– Ampicillin plus Gentamycin plus Ampicillin

(post) or Amoxicillin– Alternate regimen: Vancomycin plus

Gentamycin

Question 1:Question 1:

T/F Streptococcus is responsible for more than 50% of Native Valve Endocarditis.

Question 2:Question 2:

Embolic clinical features of infective endocarditis include:

A) CNS complications

B) Pulmonary complications

C) Coronary Artery Emboli

D) All of the above

Question 3:Question 3:

Small hemorrhagic painless plaques located on palms or soles are called?

A) Janeway lesions

B) Osler’s nodes

C) Roth Spots

D) Splinter hemorrhages

AnswersAnswers

1) T2) D3) A