Perioperative mortality and long-term outcome of infective endocarditis

Infective endocarditis (IE) is a disease with a high morbidity and mortality during the active phase and a considerable risk of complications during follow-up. The aim of this study is to describe the clinical features of IE associated with perioperative mortality in patients undergoing surgery and the short- and long-term prognosis of this disease after surgical treatment.

The clinical files of 150 patients (pts) admitted to our institution between 1989 and 2001 and whose final diagnosis was IE (Duke criteria) were retrospectively reviewed. Thus all patients included underwent at least 1 transthoracic examination, and a transesophageal examination if indicated. The study population was 69 patients with IE, 62 of whom (90%) underwent prosthetic valve replacement and 7 (10%) underwent explanation of pacemaker electrocatheter. In the statistical analysis, quantitative variables are expressed as means +/- SD and qualitative variables as proportions (percentages). Differences in survival were determined using the Kaplan-Meier log rank method. Associations were considered statistically significant when the p value was < 0.05.

The mean age was 56 +/- 15 years. Thirty-five cases (51%) had prosthetic valve endocarditis, 30 (39%) had native valve IE and 7 (10%) pacemaker electrocatheter IE. Fifty-two patients (75%) had positive blood cultures. The most frequent agents were S. epidermidis (14.5%), S. aureus (14.5%), Enterococci (13%) and S. viridans (10%). Total perioperative mortality was 17.4% (n = 12), and surgical mortality was 19.4%. Our study shows a statistical tendency for higher mortality in diabetic patients (50% vs. 14%, p = 0.052) and in women (29% vs. 11%, p = 0.065). In multivariate analysis, the presence of heart failure was an independent predictor of perioperative mortality (OR = 11.4; 95% CI: 2.0-215.2; p = 0.024). Accumulated mortality in the first year was 28% and 5-year mortality was 48%.

Prosthetic valve replacement in patients with IE is associated with high perioperative mortality (17.4%). Despite good early postoperative results, the mortality rate increases during the first year as well as the need for reoperation.