Effects of pathogenic factors on prognosis in patients with prosthetic valve endocarditis.

INTRODUCTION Despite progress in medicine, the prevalence of infective endocarditis (IE) in patients with prosthetic valves (PVE) has not decreased. Positive blood and valve cultures are one of the most important diagnostic criteria of IE. There are no unambiguous data regarding the influence of pathogenic factors on prognosis. AIM To analyse blood and valve cultures in patients with PVE and assess their impact on the risk of early and late deaths as well as IE relapse. METHODS The study group consisted of 71 PVE patients. Infective endocarditis was diagnosed based on the Polish Cardiac Society guidelines. Early and late mortality as well as IE relapse were analysed in patients hospitalised between 1988 and 1998. RESULTS Positive blood cultures were found in 55 (77.5%) patients. Early mortality was 15.5% (11 deaths). Coagulase-negative Staphylococcus infection was an independent risk factor of early death (p=0.02). During long-term follow-up 8 (13.3%) patients died. The risk of late death increased with positive valve culture (p=0.04). Recurrence of IE was diagnosed in 6 (10%) patients. Staphylococcus epidermidis was a risk factor of disease relapse (p=0.03). Six-year survival was 73%. CONCLUSIONS 1. Coagulase-negative Staphylococcus aetiology increases the risk of early death in patients with PVE. 2. Pathogenic factors did not influence the risk of late death. 3. The risk of late death was increased with positive valve culture with negative blood cultures. 4. Staphylococcus epidermidis aetiology increases the risk of PVE relapse.