Methods STUDY POPULATION

Prosthetic valve endocarditis (PVE) was encountered in 20 out of 821 patients (2-4%) who underwent valve replacement between 1 January 1981 and 30 June 1985. At a follow-up time 6-60 months later the actuarial risk of PVE was 1 % yr~l. The incidence of PVE was higher after bioprosthetic replacement (5%), after aortic valve replacement (3-4%) and in patients operated on for antecedent endocarditis of either the native or the prosthetic valve (10%). The overall mortality was 40 %. Surgical treatment improved chances of survival (27 % mortality) compared to medical treatment (80%, mortality) independently of other factors (bioprosthesis or mechanical prosthesis, aortic or mitral position, early or late onset PVE). Prosthetic valve endocarditis (PVE) is a serious complication of valve replacement. The incidence has previously been estimated as being between 1 and 9-4 % of patients'1'. The true incidence, however, may be either underestimated due to the lack of follow-up studies, or overestimated due to the lack of uniformly accepted diagnostic criteria. In the present study we wished to define the incidence of PVE and to define risk factors for the development and outcome of PVE in a large group of patients studied and followed prospectively