Background: The frequency of complications of infective endocarditis and their influence on the outcome of the patients changed in the antibiotic era. Therefore, we evaluated the complications in a recent large series of patients with infective endocarditis.
Methods: We studied 300 episodes of endocarditis in 287 patients in a tertiary cardiology referral center. Predisposing cardiac conditions were valvular heart disease in 147 episodes, congenital heart disease in 37, other heart diseases in five, and prosthetic heart valves in 69. In 69 episodes, there was no previous heart disease. The infecting microorganisms were streptococci in 147 episodes, Staphylococcus aureus in 59, Staphylococcus epidermidis in 14, gram-negative bacteria in 16, other gram-positive bacteria in eight, and fungi in four. In 52 episodes, blood cultures were negative. Seventy-eight patients (26%) died. Complications were defined as any clinically unfavorable event occurring during treatment.
Results: A total of 386 complications occurred in 223 episodes (74%); one complication occurred in 128 episodes (57%), two in 57 (26%), three in 18 (8%), four in 13 (6%), five in three (1%), and six or more in three (1%). The complications were as follows: cardiac, 100 occurrences; neurological, 72; septic, 46; associated with medical treatment, 41; renal, 27; extracranial systemic arterial embolism, 16; septic pulmonary embolism, 26; complications related to surgical treatment, 11; acute prosthetic heart valve insufficiency, six; splenic infarction or abscess, three; cardiac rhythm disturbances, three; and other, 19. The distribution of the complications relative to outcome of the patients revealed that fatality exceeded survival rates for neurologic and septic complications.
Conclusions: Complications may be common in patients with infective endocarditis. Cardiac complications were the most common ones, but fatality rates were higher for neurologic and septic complications. Hence, heart failure was replaced by neurologic and septic complications as the leading causes of death in patients with infective endocarditis.