Mitral valve prolapse and the risk of stroke after initial cerebral ischemia.

Referral-based studies suggest that patients with cerebral ischemia and mitral valve prolapse are prone to recurrent cerebral ischemic events. Our purpose was to determine the risk of subsequent stroke in a population-based group of patients with ischemic stroke or TIA and mitral valve prolapse. From 1975 through 1990, 49 residents of Olmsted County, MN, had an initial ischemic stroke or TIA and echocardiographically diagnosed mitral valve prolapse. Risk of subsequent stroke in this cohort was compared with the age- and sex-adjusted rates of recurrent stroke after initial cerebral ischemia in the Rochester, MN, population. Mean age of the patients was 72 years. Thirty-one (63%) were women. Nine had subsequent stroke (5.5 per 100 person-years). For Rochester patients who had initial ischemic stroke in the period 1975 through 1984, 10.72 recurrent strokes were expected (relative risk, 0.84; 95% confidence limits, 0.38 to 1.59). For Rochester patients with initial ischemic stroke or TIA in the period 1975 through 1979, 12.31 recurrent strokes were expected (relative risk, 0.73; 95% confidence limits, 0.33 to 1.39). There is no evidence of increased subsequent stroke risk among patients with initial episodes of cerebral ischemia and mitral valve prolapse relative to the age- and sex-adjusted recurrent stroke rates in the community.