Native valve infective endocarditis in the 1970s versus the 1980s: underlying cardiac lesions and infecting organisms.

A retrospective review of the records of 135 patients with proven or suspected endocarditis, seen between January 1970 and December 1987, is presented. Among the findings: (1) Mitral valve prolapse (MVP) as an underlying lesion was more common in the 1980s group of patients (22%) than in the 1970s group (6%, p less than 0.01); (2) no significant difference was found in the occurrence of pathogens between the 1970s and the 1980s groups of patients; (3) in most patients (17 of 19) with MVP, the organisms isolated were Streptococci viridans; (4) most patients (15 of 17) with MVP had undergone a dental procedure without prior antibiotic treatment in the two months prior to admission. Prophylactic antibiotic treatment is suggested in patients with MVP undergoing dental procedure, especially in a subset of patients with flail or redundant valve leaflet as 16 of our MVP patients (out of 17) had this pathology on echocardiogram.