Mitral valve prolapse and infective endocarditis

Abstract

It is now more than 20 years since it was first suggested that mitral valve prolapse (MVP) was associated with an increased risk of infective endocarditis (IE).’ Support for the existence of this association was initially provided by case reports of IE in patients with preexisting MVP,2 series of IE patients in which persons with MVP appeared to be overrepresented,3.6 and small follow-up studies of patients with MVP documenting a relatively high incidence of IIL6eQ More recently, several casecontrol studies have been conducted in an effort to determine more accurately the magnitude of the association between MVP and IE.10-‘2 These studies have provided estimates of the relative risk of IE in persons with MVP in comparison with those without MVP. However, it is also possible to make some estimate of the absolute risk of IE (i.e., the actual probability of IE developing over a specific time intervaI) using the results of these studies together with data about the incidence of IE and prevalence of MVP in the general population. In an effort to produce the best estimates of the relative and absolute risks of IE in patients with MVP, we examine the published results of the relevant studies together with new data from a study conducted at the New York Hospital-Cornell Medical Center. We consider the risks in the total population of persons with MVP and the risks in certain subgroups identified by various characteristics postulated to be associated with a higher than average risk of IE. We consider the implications of our estimates of the risks of IE for decisions about strategies for antibiotic prophylaxis in persons with MVP.