Endocarditis

Background

  • Consider in pts w/ unexplained fever and known risk factors
  • Mitral valve most commonly affected overall; tricuspid valve most common in IVDA
  • Noninfectious vegetations can arise in pts w/ malignancy and SLE
  • S. aureus is single most common cause
  • Blood cultures are falsely negative ~5% (think HACEK organisms)
  • Only 20% have an increase in a known murmur and only 48% have a new murmur[1]

Prophylaxis

  • No longer recommended at all in the United Kingdom[2]
  • In United States, only recommended for Invasive dental procedures not routine cleanings and Invasive Respiratory Procedures: [3][4]
  1. Prosthetic valves
  2. Prior endocarditis
  3. Un-repaired congenital cyanotic heart disease
  4. Repaired congenital heart disease/valvulopathy with prosthetic material

Risk Factors

  1. IVDA
    1. Tricuspid valve most commonly affected
  2. Prosthetic heart valve
  3. Structural heart disease
    1. Rheumatic heart disease
    2. Mitral valve prolapse
    3. Bicuspid aortic valve
  4. Hemodialysis
  5. HIV infection

Clinical Features

Splinter hemorrhage

Fever

  • Present in 80% of cases

Heart murmur

  • Preexisting murmur found in 85% of cases; new murmur found in 48%

CHF

  • Acute or progressive (70%)

Embolic manifestations

CNS

  • 65% of emboli involve the CNS[5]
  • Central retinal artery occlusion

Pulmonary

  • PNA
  • Empyema

Cardiac

  • MI
  • Myocarditis

Abdominal Organs

  • Bowel, renal, splenic infarcts

Derm

  • Osler nodes - tender red/purple nodules on distal finger and toes
  • Splinter hemorrhages - nail bed hemorrhages not extending the length of the nail
  • Janeway lesions - painless macules on palms and soles due to microabscesses

Prehospital

  • Empiric antibiotics should not be given prehopsital in patients with suspected endocarditis since the accuracy of cultures drawn in hospital will be affected.

Diagnosis

Inpatient diagnosis is based on the Duke's Criteria although many of the criteria are not filled in the ED. Heightened clinical suspicion is necessary even if diagnosis does not meet the official criteria.[6]

Modified Duke Criteria[7]

  • 2 major criteria OR
  • 1 major and 3 minor criteria OR
  • 5 minor criteria

Major Criteria

  1. Positive blood culture with typical IE microorganism, defined as one of the following:
    • Typical microorganism consistent with IE from 2 separate blood cultures, as noted below:
    • Microorganisms consistent with IE from persistently positive blood cultures defined as:
      • Two positive cultures of blood samples drawn >12 hours apart, or
      • All of 3 or a majority of 4 separate cultures of blood (with first and last sample drawn 1 hour apart)
      • Coxiella burnetii detected byone positive blood culture or IgG
  2. Evidence of endocardial involvement with positive echocardiogram defined as:
    • Valvular mass or supporting structures or
    • Abscess, or
    • New disruption of a prosthetic valve or new valvular regurgitation

Minor Criteria

  1. Predisposing factor: known cardiac lesion, recreational drug injection
  2. Fever >38°C
  3. Evidence of emboli: arterial emboli,pulmonary infarcts, Janeway lesions, conjunctival hemorrhage
  4. Glomerulonephritis, Osler's nodes
  5. Positive blood culture (that doesn't meet a major criterion) or serologic evidence of infection

Work-Up

  1. Blood culture (from 3 separate sites)[8]
  2. CBC
    1. Staphylococcal endocarditis: Leukocytosis +/- thrombocytopenia
    2. Subacute endocarditis: WBC may be normal or elevated
  3. UA
    1. Hematuria
  4. ESR
    1. Elevated in >90% of cases
  5. ECG
    1. Ischemia, heart block
  6. CXR
    1. Pulmonary emboli, CHF
  7. Ultrasound
    1. Obtain as soon as possible
    2. TEE may be required for:
      1. Prosthetic valves
      2. Difficulty obtaining clear TTE images (obesity, COPD)
      3. High clinical probability of endocarditis

Management

Initial stabilization should focus on Airway, Breathing and Circulation optimization with early antibiotic and blood cultures

CHF/Cardiogenic Shock

  • Often due to valve failure, rupture, or a new defect.

Pulmonary edema

  • Often due to mitral or aortic valve rupture causing severe regurgitation
  • Focus on after-load reduction

Respiratory Failure (emboli)

  • Often requires intubation with failure either due to CHF or Pneumonia
  • Multi-lobar pneumonia suggests a tricuspid or pulmonary valve lesion with emboli to lungs

Antibiotics

  • Start after 3 sets of blood cultures are obtained (if possible)[8]

Therapy should be based on:

  1. Whether the patient has received prior antibiotic therapy
  2. Prosthetic valves
  3. Local antibiotic resistance patterns or knowledge of prior endocarditis cultures
  4. Prior hospitalizations and risk of MRSA


Native Valves

Options:[9]

Suspected MRSA:[9]

Prosthetic Valves (Early)

Early prosthetic valve endocarditis defined as < 12 months post surgery[9]

IV Drug User without Prosthetic Valve

Prosthetic Valve (Late)

Late prosthetic valve endocarditis defined as ≥ 12 months post surgery[9]
  • Same as native valve endocarditis empiric therapy

Dental Procedure Prophylaxis

All antibiotics options are given as a single dose 1 hour prior to the dental procedure

Options:[10]

Disposition

Admit all suspected cases and consult Cardiothoracic surgery for endocarditis complicated by:[1]

  1. New Heart failure suspected due to severe regurgitation
  2. Cardiogenic Shock
  3. Echocardiography demonstrating a new fistula


Complications

Cardiac

  1. Heart Failure
    • Most common cause of death due to IE
  2. Perivalvular Abscess

Embolic

  1. CVA
  2. Blindness
  3. Painful, ischemic extremities
  4. Unusual pain sydromes (due to splenic or renal infarction)
  5. Hypoxia
  6. MI

Neurologic

  1. Embolic stroke
  2. Acute encephalopathy
  3. Meningoencephalitis
  4. Purulent or aseptic meningitis
  5. Cerebral hemorrhage
  6. Seizure
  7. Spinal Abscess

Renal

  1. Infarction
  2. Glomerulonephritis

Musculoskeletal

  1. Vertebral osteomyelitis

External Links

Source

  1. ↑ 1.0 1.1 Hoen, B. et al. Infective Endocarditis. NEJM. 2013. 368;15. 1425-1433 PDF
  2. ↑ Wilson W. et al. Prevention of infective endocarditis: guidelines from the American Heart Association: a guideline from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee, Council on Cardiovascular Disease in the Young, and the Council on Clinical Cardiology, Council on Cardiovascular Surgery and Anesthesia, and the Quality of Care and Outcomes Research Interdisciplinary Working Group. Circulation 2007;116(15):e376-e377.
  3. ↑ Richey R, Wray D, Stokes T. Prophy- laxis against infective endocarditis: sum- mary of NICE guidance. BMJ 2008;336: 770-1.
  4. ↑ Wilson W, et al. Prevention of Infective Endocarditis: Guidelines from the American Heart Association. Circulation. 2007;116:1736-1754
  5. ↑ Mylonakis. E, Calderwood S. Infective endocardidits in adults. NEJM. 2001;345(18):138-1330
  6. ↑ Durack D, Lukes A, Bright D "New criteria for diagnosis of infective endocarditis: utilization of specific echocardiographic findings. Duke Endocarditis Service". Am J Med. 1994. 96 (3): 200–9
  7. ↑ Li, JS et al. "Proposed Modifications to the Duke Criteria for the Diagnosis of Infective Endocarditis". Clinical Infectious Diseases. 2000. 30(4). 633.
  8. ↑ 8.0 8.1 Lee A, Mirrett S, Reller LB, Weinstein MP. Detection of bloodstream infections in adults: how many blood cultures are needed? J Clin Microbiol 2007;45: 3546 – 3548
  9. ↑ 9.0 9.1 9.2 9.3 ESC Task Force Guidelines on the prevention, diagnosis, and treatment of infective endocarditis. European Heart Journal (2009) 30, 2369–2413 doi:10.1093/eurheartj/ehp285 PDF
  10. ↑ AHA Pocket Card Dental Prophylaxis Endocarditis
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