Incidence and Predictors of Infective Endocarditis in Mitral Valve Prolapse: A Population-Based Study

Objective: To determine the incidence and predictors of infective endocarditis (IE) in a population-based cohort of patients with mitral valve prolapse (MVP). Patients and Methods: We identified all adult Olmsted County residents with MVP diagnosed by echo-cardiography from January 1989 to December 1998 and cross-matched them with the Rochester Epidemiology Project-identified Olmsted County cases of IE from January 1, 1986, through December 31, 2006. We retrospectively analyzed and de novo confirmed each IE case using the modified Duke criteria. Results: There were 896 Olmsted County residents with echocardiographically diagnosed MVP (mean age, 53 +/- 21 years; 565 women [63%]). The mean follow-up period was 11 +/- 5 years. The 15-year cohort risk of IE after MVP diagnosis was 1.1%+/- 0.4% (incidence, 86.6 cases per 100,000 person-years; 95% CI, 43.3-173.2 cases per 100,000 person-years); thus, the age-and sex-adjusted relative risk of IE in patients with MVP was 8.1 (95% CI, 3.6-18.0) in comparison to the general population of Olmsted County (P<.001). There were no IE cases in patients without previously diagnosed mitral regurgitation (MR). Conversely, IE incidence was higher in patients with MVP with moderate, moderate-severe, or severe MR (289.5 cases per 100,000 person-years; 95% CI, 108.7-771.2 cases per 100,000 person-years; P=.02 compared with trivial, mild, or mild-moderate MR) and in patients with a flail mitral leaflet (715.5 cases per 100,000 person-years; 95% CI, 178.9-2861.0 cases per 100,000 person-years; P=.02 compared with no flail mitral leaflet). Conclusion: The population-based incidence of IE in adults with MVP is higher than those previously reported in case-control, tertiary care center studies. Patients with MVP and moderate, moderate-severe, or severe MR or a flail mitral leaflet are at a notable risk of developing IE in comparison with those without MR. (C) 2016 Mayo Foundation for Medical Education and Research