Diagnosis

Endocarditis

Etiology

Cause [3y8]

• Native valve endocarditis (56.6%)

• Prosthetic valve endocarditis (30.1%)

• Device-related endocarditis (9.9%)

• Microbe: [91h][nq3]

  • Acute endocarditis: Staphylococcus aureus (25-30%), group A/B/C/D/G streptococci, Streptococcus viridans

  • Subacute endocarditis: alpha-hemolytic streptococci, enterococci, HACEK (Haemophilus aphrophilus, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, Kingella kingae), Candida albicans

Pathophysiology [zq9][nq3]

1. Prodromal endocardial injury (catheter/electrode/surgery/IV drugs) --> Turbulence or trauma to the endothelial surface (fibrin-platelet vegetation)

2. Medical procedure (oral surgery, endoscopy) --> Bacteremia delivers the organisms

3. Adherence of the organisms

4. Eventual invasion of the valvular leaflets --> vegetations:

   • Septic emboli

   • Circulating immune complexes (glomerulonephritis and vasculitis)

Risk factors [zq9][nq3]

• Previous endocarditis

• Congenital heart disease (15% of cases, VSD, PDA, Fallot)

• Intravenous drug use

• Prosthetic valve

• Degenerative heart disease (bicuspid aortic valve)

• Rheumatic heart disease

• Mitral valve prolapse

• Intravascular device

Complications [zq9][nq3]

• Valvular insufficiency --> heart failure (valve perforation, rupture of chordae tendineae and papillary muscles)

• Myocardial infarction

• Pericarditis

• Cardiac arrhythmia

• Myocardial abscesses

• Sinus of Valsalva aneurysm

• Arterial emboli

• Mycotic aneurysms

• Arthritis

• Myositis

• Glomerulonephritis

• Acute renal failure

• Stroke

• Mesenteric abscess/infarction

• Splenic abscess/infarction

Epidemiology

Incidence per 100.000 [tow][91h][3y8][qn7][w4d][s31]

Approach

• Blood test [zq9]

• Blood culture

• Echocardiography:

  • identify vegetations

  • characterize the hemodynamic severity

  • assess ventricular function and pulmonary pressures

  • detect complications

• Transesophageal echocardiography

• Cardiac CT

• PET CT scan

Dukes clinical criteria for diagnosis

• 2 major criteria; or

• 1 major criterion and 3 minor criteria; or

• 5 minor criteria

Major Criteria

1. Blood culture positive for typical microorganisms consistent with endocarditis from 2 separate blood cultures: Viridans streptococci, Streptococcus bovis, HACEK group (Haemophilus spp., Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella spp., and Kingella kingae), Staphylococcus aureus; or community-acquired enterococci

2.  Transesophageal echocardiogram:

   • Oscillating intracardiac mass on valve

   • Abscess

   • New partial dehiscence of prosthetic valve

3. New valvular regurgitation (worsening of pre-existing murmur not sufficient)

Minor Criteria

1. Predisposing heart condition, or injection drug use

2. Fever, temperature >38° C

3. Vascular phenomena: major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, intracranial hemorrhage, conjunctival hemorrhages, and Janeway lesions

4. Immunologic phenomena: glomerulonephritis, Osler’s nodes, Roth’s spots, and rheumatoid factor

5. Microbiological evidence: positive blood culture but does not meet a major criterion as noted above or serological evidence of active infection with organism consistent with endocarditis

Treatment

American College of Cardiology - Practice Guidelines: [zgu]

1. Antibiotic therapy with guidance from blood culture sensitivity [nq3]

   • Native valve: Ceftriaxone 2 g/day + Gentamicin 3 mg/kg/day for 2-4 weeks

   • Prosthetic: Penicillin G 24 million IU/day or Ceftriaxone +/- Gentamicin for 6 weeks

   • MRSA: Vancomycin 15mg/kg/12hr or Daptomycin 8 mg/kg/day for 6-weeks

2. If embolism --> consider to temporarily discontinue anticoagulation

3. If pacer/ICD present --> remove hardware

4. Surgery if:

   • Valve dysfunction causing heart failure

   • Resistant organism (S.aureus, fungi)

   • Heart block or abscess

   • Persistent infection (>7 days after onset of antibiotics)

   • Relapsing prosthetic valve endocarditis

   • Persistent vegetations despite appropriate antibiotic therapy

   • Mobile vegetations greater than 10 mm in length

Differential diagnoses

Abdominal abscess, Antiphospholipid syndrome, Aortic dissection, Discitis, Heart failure, Intracerebral hemorrhage, Lyme disease, Meningitis, Myocardial infarction, Myocarditis, Myxoma, Pericarditis, Pleural empyema, Pneumonia, Polymyalgia rheumatica, Pulmonary embolism, Reactive arthritis, Rheumatoid arthritis, Stroke, Systemic lupus erythematosus, Temporal arteritis, Tricuspid regurgitation, Vasculitis