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Endocarditis, Emergency Medicine

Basics

Description

- Various cardiac structures may be involved: - Native heart valves (most common) - Prosthetic valves - Interventricular septum - Chordae tendineae - Mural endocardium - Intracardiac devices

- Almost always secondary to bacterial infection - Rare noninfectious causes - Nonbacterial thrombic endocarditis or marantic endocarditis - Often due to a hypercoagulable state - Small sterile vegetations

- Septic embolization - Cerebral complications - Cerebral embolism - Intracranial hemorrhage - Cerebral abscess

- Common organisms: - Staphylococcus aureus (most common pathogen): - Seen in all populations, especially IVDA and toxic illness - Sometimes metastatic

- Streptococcus bovis: - Common association with colonic polyps or GI malignancy

- Staphylococcus epidermidis - Enterococci: - Seen in young women and old men following instrumentation or infection

- Respiratory: - Dyspnea - Cough - Heart failure

- Extremities: - Myalgias - Arthralgias - Digital clubbing

- Skin: - Cutaneous vasculitic lesions: - Mucosal and conjunctival petechiae - Splinter hemorrhages - Osler nodes: Erythematous, painful tender nodules - Janeway lesions: Erythematous or hemorrhagic, macular or nodular lesions, a few millimeters in diameter on the hands and feet

- Fever duration and pattern - Risk factors: - Prior cardiac disease - Source of bacteremia: - Indwelling intravascular catheters - IV drug use - Poor dental hygiene

- Assess for splenomegaly. - Assess for septic emboli: - Fundi, skin, nail beds - Careful neurologic exam for small focal deficits

- EKG - Arrhythmia, new heart block

- Echocardiogram - Acute valvular pathology - Abscess - Vegetations - Transesophageal echo provides greater sensitivity.

- Monitor for signs of heart failure. - Operative repair if: - Severe valvular dysfunction causing failure - Unstable prosthesis - Perivalvular extension with intracardiac abscess - Antimicrobial therapy failure - Large or fungal vegetations

- Prosthetic valve or history of IVDA: - Vancomycin + gentamicin + rifampin - Nafcillin + gentamicin + rifampin (if methicillin-resistant S. aureus [MRSA] is not suspected) - If MRSA vancomycin failure/intolerant consider daptomycin or quinupristin-dalfopristin - Vancomycin resistant - Enterococcus faecium consider quinupristin-dalfopristin - Enterococcal: Penicillin G + gentamicin; vancomycin + gentamicin - Enterococcal (gentamicin resistant): Penicillin G + streptomycin

An inflammation of the endothelial surface of the heart

  • Various cardiac structures may be involved:Native heart valves (most common)Prosthetic valvesInterventricular septumChordae tendineaeMural endocardiumIntracardiac devices
  • Characterized by a vegetation (a thrombus with superimposed microorganisms)Bacterial colonization of the initially sterile vegetation composed of fibrin and plateletsBacterial growth enlarges the vegetation, further impeding blood flow and inciting inflammation.Propagation of the infection through systemic emboli
  • Almost always secondary to bacterial infection
  • Rare noninfectious causesNonbacterial thrombic endocarditis or marantic endocarditisOften due to a hypercoagulable stateSmall sterile vegetationsLibman-Sacks endocarditisComplications of lupus erythematosusDue to the deposition of immune complexes that cause an inflammatory reactionSmall vegetations

Epidemiology

  • More common in men (ratios from 3.2 to 9.1)M: 8.6-12.7 cases/100,000 person-yrF: 1.4-6.7 cases/100,000 person-yr
  • Risk factors:Older patientsPoor dental hygieneComorbiditiesRheumatic heart diseaseProsthetic valveHemodialysisDiabetesIV drug abuse (IVDA):Greater risk than rheumatic heart disease or prosthetic valvesPredilection for right-sided heart valves
  • Septic embolizationCerebral complicationsCerebral embolismIntracranial hemorrhageCerebral abscessExtracerebral embolic eventsPulmonarySplenicRenalMycotic aneurysms (aorta, renal artery, splenic artery, hepatic artery, mesenteric arteries, etc.)HepaticCoronary
  • Risk factor for recurrent endocarditis:Structural heart disease serves as common vegetative site due to altered intracardiac flow:Mitral valve prolapseAortic valve dysfunctionCongenital heart disorders in the pediatric populations:Tetralogy of FallotAortic stenosisPatent ductus arteriosusVentricular septal defectsAortic coarctationProsthetic valvesIndwelling cathetersAny mechanical device may serve as a portal of entry or attachment for microorganisms.

Etiology

  • Major categories:Bacterial endocarditisProsthetic valve endocarditisNonbacterial thrombotic endocarditis:MalignancyUremiaBurnsSystemic lupus erythematosus
  • Common organisms:Staphylococcus aureus (most common pathogen):Seen in all populations, especially IVDA and toxic illnessSometimes metastaticStreptococcus viridans:Found in oropharynx, common agent in native valve endocarditisStreptococcus bovis:Common association with colonic polyps or GI malignancyStreptococcus pneumoniae:Causes rapid valvular destruction, abscess, and CHFRisk factor: AlcoholismStaphylococcus epidermidisEnterococci:Seen in young women and old men following instrumentation or infectionCandida and Aspergillus:Found in IVDA, prosthetic valves, or immunocompromised patientsHACEK (Haemophilus sp.)Culture-negative endocarditis (Q fever, psittacosis, Bartonella, brucellosis)

Diagnosis

Signs and Symptoms

  • Fever:Present in 86% of patientsMay be absent in certain settings:ElderlyCHFSevere debilityChronic renal failureFlulike illnessChillsSweatsRigorsMalaise
  • Head, eyes, ears, nose, and throat:Retinal hemorrhages or Roth spots
  • Respiratory:DyspneaCoughHeart failure
  • Cardiac:A new or changing murmur in 80-85% of patients
  • Abdominal:Abdominal or back painSplenomegaly (15-50%)
  • Extremities:MyalgiasArthralgiasDigital clubbing
  • Neurologic:Altered mental statusSeptic embolization (stroke or mycotic aneurysm)
  • Skin:Cutaneous vasculitic lesions:Mucosal and conjunctival petechiaeSplinter hemorrhagesOsler nodes: Erythematous, painful tender nodulesJaneway lesions: Erythematous or hemorrhagic, macular or nodular lesions, a few millimeters in diameter on the hands and feet

History

  • Fever duration and pattern
  • Risk factors:Prior cardiac diseaseSource of bacteremia:Indwelling intravascular cathetersIV drug usePoor dental hygiene

Physical Exam

  • Heart and lung exam:New cardiac regurgitant murmurHeart failure
  • Assess for splenomegaly.
  • Assess for septic emboli:Fundi, skin, nail bedsCareful neurologic exam for small focal deficits

Essential Workup

  • Identify risk factors for endocarditis in patients with fever of unknown etiology.
  • Blood cultures
  • ECG is needed to confirm the diagnosis.

Diagnosis Tests & Interpretation

Lab

  • CBC:Anemia (sometimes hemolytic)Leukocytosis (with granulocytosis and bandemia)
  • Blood cultures:Multiple sets (3 sets over a time period) should be obtained before antibiotic administration:5-10% with endocarditis have false-negative culturesConsider culture of catheter device
  • Elevated sedimentation rate and C-reactive protein (lacks specificity)
  • Urinalysis:

Imaging

  • CXR:CHFSeptic pulmonic emboli, which may be seen in right-sided endocarditis
  • EKGArrhythmia, new heart block
  • EchocardiogramAcute valvular pathologyAbscessVegetationsTransesophageal echo provides greater sensitivity.
  • CT scanMay provide comprehensive information and valvular abnormalities

Differential Diagnosis

  • Rheumatic fever
  • Atrial myxoma
  • Acute pericarditis
  • MI
  • Aortic dissection with regurgitant valve
  • Thrombotic thrombocytopenic purpura
  • Systemic lupus erythematosus
  • Occult neoplasm with metastasis
  • Septicemia
  • Cotton fever

Treatment

Initial Stabilization/Therapy

  • Monitor for signs of heart failure.
  • Operative repair if:Severe valvular dysfunction causing failureUnstable prosthesisPerivalvular extension with intracardiac abscessAntimicrobial therapy failureLarge or fungal vegetations
  • Antibiotic therapy:IV, bactericidal, and empiric, pending culture resultsNative valve or congenital abnormality:Penicillin G + nafcillin + gentamicinVancomycin + gentamicinProsthetic valve or history of IVDA:Vancomycin + gentamicin + rifampinNafcillin + gentamicin + rifampin (if methicillin-resistant S. aureus [MRSA] is not suspected)If MRSA vancomycin failure/intolerant consider daptomycin or quinupristin-dalfopristinVancomycin resistantEnterococcus faecium consider quinupristin-dalfopristinEnterococcal: Penicillin G + gentamicin; vancomycin + gentamicinEnterococcal (gentamicin resistant): Penicillin G + streptomycinFungal:HACEK:

Medication

  • Amphotericin B:Test dose 0.1 mg/kg up to 1 mg slow IVWait 2-4 hr.If tolerated, begin 0.25 mg/kg IV and advance to 0.6 mg/kg IV QID
  • Ceftriaxone: 2 g/d IV (peds: 100 mg/kg/24h)
  • Daptomycin: 4 mg/kg/d U IV
  • Gentamicin: 1 mg/kg IV q8h (peds: 3 mg/kg/24h in 3 equally div. doses)
  • Nafcillin: 2 g IV q4h
  • Penicillin G: 4 million IU IV q4h (peds: 300,000 U/kg/d div. into 4 equal doses)
  • Quinupristin-dalfopristin: 7.5 mg/kg IV q8h (peds: 7.5 mg/kg/12h)
  • Rifampin: 600 mg PO QID
  • Streptomycin: 15 mg/kg/24h IV/IM in 2 equally div. doses (peds: 20 mg/kg/24h IV in 2 equally div. doses)
  • Vancomycin: 15 mg/kg IV q12h (peds: 40 mg/kg/24h in 2-3 equally div. doses)

Follow-Up

Disposition

Admission Criteria

  • Patients with risk factors who exhibit pathologic criteria or clinical findings
  • All IV drug users with fever
  • Admit patients with cardiovascular instability to an intensive care unit/monitored setting.

Discharge Criteria

None

Follow-Up Recommendations

  • Expected course:Most patients will defervesce within 1 wk.
  • Complications:Cardiac: CHF, valve abscess, pericarditis, fistulaNeurologic: Embolic stroke, abscess, hemorrhageEmbolization: CNS, pulmonary, ischemic extremitiesMycotic aneurysms: Cerebral or systemicRenal: Infarction, nephritis, abscessMetastatic abscess: Kidney, spleen, tissue

Pearls and Pitfalls

  • Fever, new or changing murmur
  • 50% of cases occur in patients with no known history of valve disease
  • Recent health care exposure/device consider as risk factor
  • Common complications; watch for stroke, embolization, heart failure, intracardiac abscess
  • Admit IV drug abusers presenting with fever to rule out endocarditis.
  • Empiric therapy for acutely ill after 2-3 sets of blood cultures from separate venipuncture sites.

Additional Reading

  • Chen RS, Bivens MJ, Grossman SA. Diagnosis and management of valvular heart disease in emergency medicine. Emerg Med Clin North Am. 2011;29(4):801-810.
  • Hoen B, Duval X. Clinical practice. Infective endocarditis. N Engl J Med. 2013;368(15):1425-1433.
  • Keynan Y, Rubinstein E. Pathophysiology of infective endocarditis. Curr Infect Dis Rep. 2013;15(4):342-346.
  • Murdoch DR, Corey GR, Hoen B, et al. Clinical presentation, etiology, and outcome of infective endocarditis in the 21st century: The International Collaboration on Endocarditis-Prospective Cohort Study. Arch Intern Med. 2009;169(5):463-473.
  • Selton-Suty C, C ©lard M, Le Moing V, et al. Preeminence of Staphylococcus aureus in infective endocarditis: A 1-year population-based survey. Clin Infect Dis. 2012;54(9):1230-1239.

Codes

ICD9

  • 421.0 Acute and subacute bacterial endocarditis
  • 424.90 Endocarditis, valve unspecified, unspecified cause
  • 996.61 Infection and inflammatory reaction due to cardiac device, implant, and graft
  • 424.91 Endocarditis in diseases classified elsewhere
  • 424.99 Other endocarditis, valve unspecified

ICD10

  • I33.0 Acute and subacute infective endocarditis
  • I38 Endocarditis, valve unspecified
  • T82.6XXA Infect/inflm reaction due to cardiac valve prosthesis, init
  • I39 Endocarditis and heart valve disord in dis classd elswhr
  • M32.11 Endocarditis in systemic lupus erythematosus

SNOMED

  • 56819008 Endocarditis (disorder)
  • 301183007 Bacterial endocarditis (disorder)
  • 233853009 Prosthetic valve endocarditis (disorder)
  • 57181007 Nonbacterial thrombotic endocarditis (disorder)
  • 459057007 Viral endocarditis (disorder)
  • 54072008 Nonbacterial verrucal endocardiosis (disorder)
  • 73028002 staphylococcal endocarditis (disorder)
  • 86100009 Vegetative endocarditis
  • 86348002 Mycotic endocarditis (disorder)
  • 89736004 Valvular endocarditis