Infective Endocarditis

Today's case involved an 88-year-old man with a history of aortic valve replacement and multiple CABG surgeries who had a one-week history of fever.  His blood cultures were positive for Streptococcus gallolyticus and there was possible but not conclusive echocardiographic evidence of endocardial involvement.

There were multiple learning points:

-Organisms like S. gallolyticus (formerly S. bovis), S. viridans, S. aureus, HACEK organisms, and enterococci should spur suspicion in our minds regarding the possibility of infective endocarditis

-We discussed some of the symptoms of endocarditis including fever/constitutional symptoms, immune phenomena (Roth spots, Osler nodes, glomerulonephritis, positive rheumatoid factor), vascular phenomena (Janeway lesions, septic emboli, splinter hemorrhages), and symptoms of valvular dysfunction including congestive heart failure

-We discussed the Duke criteria for infective endocarditis

-We discussed the relationship between S. gallolyticus bacteremia and colon pathology (notably cancer)

-We discussed surgical indications for infective endocarditis which include persistent bacteremia/treatment failure, decompensated hemodynamics/heart failure, valvular abscess, vegetation greater than 1.0 cm, difficult to treat orgnanisms (e.g. Candida species), and refractory septic emboli

-Pacemaker lead removal should be considered if there is evidence of lead infection

-Cardiovascular surgeons will often be reluctant to operate on patients with septic neurologic consequences because of the risk of intracranial hemorrhage when they go on cardiovascular bypass with significant heparinization

-S. aureus has surpassed S. viridans as the most common cause of IE as a result of increasing use of vascular access devices/implants

Further Reading:

N Engl J Med. 2013 Apr 11;368(15):1425-33. doi: 10.1056/NEJMcp1206782.