Clinical outcome and long-term prognosis of late prosthetic valve endocarditis: a 20-year experience.

A prospective study of the clinical characteristics and evolutionary patterns of 59 cases of late prosthetic valve endocarditis (LPVE) that occurred between January 1975 and December 1994 was performed. Of these 59 cases of LPVE, 48 involved mechanical valves and 11 involved biological valves. Etiologies were as follows: streptococci, 41% of cases; staphylococci, 25%; enterococci, 13%; and miscellaneous, 21%. Echocardiography documented vegetations in 21 patients, paravalvular abscesses in 10, and prosthetic leaks in 34. Emboli occurred in 22 patients, and heart failure in 19 patients. Forty-two patients received medical treatment alone, and 17 received medical treatment and underwent valve replacement surgery. The in-hospital mortality rate was 25%; staphylococcal infection caused 67% of deaths, streptococcal infection caused 5%, and other etiologies caused 23% (P = .0004). After adjustment for age and type of prosthesis, multiple logistic regression revealed an odds ratio for death due to nonstreptococcal infections of 9.67. The overall survival rate was 59% at 5 years and 52% at 10 years. During follow-up, 17 patients needed new valves. At the end of follow-up, only 13 patients remained alive and had the same prosthesis that they had at the time of the diagnosis of LPVE.