Duration of fever during treatment of infective endocarditis

We reviewed the duration of fever among 123 patients treated for infective endocarditis at University Hospitals of Cleveland between 1972 and 1984. One half of these patients became afebrile within 3 days after initiation of antibiotic therapy and nearly three quarters were afebrile after 1 week of therapy. After 2 weeks of therapy, nearly 90% had defervesced. Endocarditis due to Staphylococcus aureus or gram-negative bacilli, and culture-negative endocarditis, were associated with prolonged fever. Microvascular phenomena, major vessel embolization, or vegetations seen on 2-D echocardiogram also were associated with prolonged fever. Multivariate analysis revealed that only microvascular phenomena or major vessel embolization were independently associated with longer duration of fever. Endocarditis-associated mortality among patients who remained febrile after 1 week of therapy was 18%, and this was greater than the 2% mortality among patients who defervesced (p less than 0.002). These data suggest that prolonged fever during treatment of infective endocarditis is often due to tissue infarction or vascular injury. Prolonged fever also identifies patients at higher risk of a fatal outcome.