Snapshot A 25-year-old woman presents to the emergency room for a fever. She has a history of intravenous drug use and had previously been treated for osteomyelitis. On physical exam, she is febrile, and heart auscultation reveals a new systolic murmur at the lower left sternal border. An echocardiogram reveals tricuspid valve vegetations. Summary Endocarditis is an acute cardiac condition characterized by inflammation of the heart valve, typically secondary to bacterial infection. It is typically the result of bacteremia, often due to surgery, dental procedures, or as a complication of congenital heart disease. Patients present with systemic symptoms such as fatigue, fever/chills, new onset cardiac symptoms (murmur, heart failure), and if severe enough, end-organ damage. Classic skin manifestations such as Osler nodes, Janeway lesions, and splinter hemorrhages are also characteristic of the condition. Diagnosis is made via the Duke criteria, which involves meeting 2 major criteria, 1 major and 3 minor criteria, or 5 minor criteria. Major criteria include two positive blood cultures and echocardiography evidence. Minor criteria include fever, embolic signs, one positive blood culture, and other immunologic phenomena such as skin manifestations or kidney damage. Treatment is antibiotics or surgical valve replacement depending on the severity and chronicity of the disease. Epidemiology Incidence common > 1/100,000 Demographics typically affects adults > 60 years old men are more commonly affected than females Location mitral valve > tricuspid valve tricuspid valve disease is associated with intravenous (IV) drug use Staphylococcus aureus, Pseudomonas, and Candida Risk factors rheumatic heart disease IV drug use immunosuppression prosthetic heart valve congenital heart disease ETIOLOGY Pathophysiology mechanism of injury endothelial damage on the surface of the cardiac valve can cause a thrombus to form login to view 1 more bullet bacteria can then adhere to thrombus vegetations are caused by further depositions of fibrin and platelets acute endocarditis Streptococcus pneumoniae Streptococcus pyogenes Staphylococcus aureus login to view 2 more bullets Neisseria gonorrhea subacute bacterial endocarditis characterized by slower onset and less severe symptoms Streptococcus galloyticus login to view 2 more bullets Enterococcus login to view 1 more bullet Streptococcus viridans login to view 3 more bullets Staphylococcus epidermidis login to view 2 more bullets Candida albicans login to view 1 more bullet non-infectious endocarditis Libman-Sacks endocarditis login to view 2 more bullets non-bacterial thrombotic (marantic) endocarditis login to view 3 more bullets Associated conditions systemic infection can lead to cardiogenic shock and eventual heart failure septic emboli can dislodge and lead to end organ damage or stroke Anatomy Both native and prosthetic valves serve as the site for infection valves most frequently involved: mitral valve > aortic valve > tricuspid valve > pulmonic valve in IV drug users the tricuspid valve is most commonly affected since it is reached first from the venous return Presentation Symptoms persistent fevers (the most common symptom) shortness of breath systemic symptoms weakness fever malaise Physical exam auscultation findings new murmur login to view 4 more bullets inspection from emboli login to view 5 more bullets from immune complex deposition login to view 2 more bullets Imaging Echocardiography indication for all patients views transthoracic echocardiography (TTE) is recommended for initial inspection login to view 1 more bullet findings vegetations on valves login to view 1 more bullet Studies Serum labs leukocytosis with left shift positive bacterial blood cultures ↑ C-reactive protein ↑ erythrocyte sedimentation rate Electrocardiogram indications patients with associated chest pain findings rule out acute coronary syndrome Differential Noninfective endocarditis findings found in noninfective endocarditis and not infective endocarditis negative peripheral blood cultures asymptomatic unless embolization occurs Osteomyelitis findings found in osteomyelitis and not infective endocarditis lack of systemic embolic symptoms diagnosis Duke Criteria Major (2 Criteria) Minor (5 Criteria) 1. Positive blood cultures from 2 separate blood cultures drawn > 12 hours apart, 3 out of 4 blood cultures that are positive, with first and last samples drawn 1 hour apart, single positive blood culture for Coxiella burnetti, or antiphase I IgG antibody titer > 1:800 1. Fever 2. Abnormal echocardiogram with vegetation or abscess or partial dehiscence of prosthetic valve 2. Presence of risk factors, including intravenous drug use, structural heart disease, prosthetic heart valve, dentla procedures, or history of endocarditis 3. Vascular phenomena, including Janeway lesions, emboli, mycotic aneurysm, and conjunctival hemorrhage 4. Immunologic phenomena, including glomerulonephritis, Osler nodes, and Roth spots 5. Positive blood cultures not meeting major criterion 6. Echocardiographic findings consistent with endocarditis but not meeting major criterion Making the diagnosis based on clinical presentation and Duke criteria pathologic criteria login to view 4 more bullets clinical criteria: one of the following login to view 3 more bullets if blood cultures are negative but echocardiography shows endocarditis, consider one of the causes of culture-negative endocarditis (CNE) Coxiella burnetii Bartonella spp HACEK organisms login to view 5 more bullets Treatment Management approach choice of antibiotics ultimately depend on causative agent and susceptibility as well as presence of prosthetic material in the heart all anitbiotics should given intravenously Nonoperative Medical penicillin or ceftriaxone indications login to view 2 more bullets vancomycin indications login to view 2 more bullets vancomycin plus gentamicin and rifampin indications login to view 2 more bullets vancomycin plus cefepime/piperacillin-tazobactam for critically ill/unstable patients coverage for Pseudomonas aeruginosa as more common in IV drug users Operative surgical valve replacement approach login to view 1 more bullet indications login to view 3 more bullets technique login to view 1 more bullet complications login to view 3 more bullets Complications Heart failure incidence up to 40-50% of patients treatment pharmacological agents login to view 3 more bullets operative login to view 1 more bullet Perivalvular abscess incidence up to 30-40% of patients treatment antibiotic treatment for <1 cm abscess surgical removal if >1 cm Splenic abscesses incidence around 5% of patients treatment antibiotics splenectomy Cerebrovascular accident incidence estimated to be 35% of patients treatment thrombolytics thrombectomy Prognosis Overall poor prognosis 1-year mortality rate is around 30% poor prognostic factors include high risk for emboli login to view 2 more bullets visible vegetations prosthetic valve endocarditis female gender advanced age history of drug abuse Endocarditis prophylaxis may be required before dental procedures 2017 American Heart Association guidlines indicate antibiotic prophlaxis to prevent endocarditis only in patients with: history of prosthetic valve (or with valve components) history of unrepaired congential heart disease history of repaired congential heart disease with residual shunt post-cardiac transplant with valve regurgitation history of prior infectious endocarditis