Clinical profile, prognosis and treatment of patients with infective endocarditis--a 14-year follow-up study

Abstract

Introduction: Poor prognosis of infective endocarditis (IE) is not only attributable to high morbidity and mortality during an active phase of the disease, but also to late complications and relapses occurring after eradication of the infection. Identification of unfavorable prognostic factors allows to optimize therapeutic modalities in patients with particularly poor prognosis.

Objectives: To determine clinical features and long-term prognosis among patients with IE.

Patients and methods: The study group consisted of 69 IE patients hospitalized in our center between 1992 and 2005. The diagnosis of IE was based on the Duke University criteria. The mean age was 52 +/- 12 years. Surgical treatment was performed in 48 (70%) cases.

Results: The etiology of IE was Staphylococcus sp. in 32% of patients, Streptococcus sp. in 16% of patients, in 41% of cases blood cultures were negative. The infection was located on the aortic (43%), mitral (26%), tricuspid (8%) and multiple valves (20%). During 1-14 years of follow-up, 27 patients died (39%). Prognostic factors included NYHA class of heart failure (p = 0.031), lower left ventricular ejection fraction (p = 0.017), kidney failure (p = 0.012), atrial fibrillation (p = 0.006), a history of rheumatic valve disease (p = 0.046). In multivariate logistic analysis the only significant parameter related to poor prognosis after IE was atrial fibrillation. The analysis of receiver operating characteristic curve showed that patients with atrial fibrillation were significantly associated with higher mortality (HR 5.35, 95% CI 1.47-19.56, p = 0.011).

Conclusions: Regardless of the mode of treatment (medical or combined medical-surgical), the mortality of patients with infective endocarditis remains relatively high. In this study atrial fibrillation seems to be the most important risk factor of death.