Prevalence of mitral valve prolapse in ethnic groups.

Mitral valve prolapse (MVP) was reported to be a common disorder occurring in 5% to 15% of the general population and to be frequently associated with serious complications. The reported high prevalence and complication rates of MVP have been challenged recently by the findings of the Framingham Heart Study, which was conducted in a Caucasian population; the findings in other ethnic groups remain uncertain. The prevalence of MVP was studied in a true population sample comprising 972 Canadians of South Asian (n=336), European (n=322) and Chinese (n=314) descent. MVP was diagnosed by two-dimensional echocardiography. The prevalence of MVP for the entire study cohort was 2.7% and did not differ significantly between the three ethnic groups evaluated (2.7% in South Asian, 3.1% in European and 2.2% in Chinese [P=0.79]). Age, sex, history of cardiac risk factors, blood pressure, abnormalities on electrocardiography, left atrial size, left ventricular end-diastolic and end-systolic diameters and volumes, and left ventricular ejection fraction were similar in subjects with and without MVP. There was a trend toward lower body mass index in subjects with MVP compared to those without MVP (24.5+/-5.5 kg/m(2) versus 26.0+/-4.3 kg/m(2), respectively, P=0.10). The prevalence of cardiovascular diseases, including history of angina, previous myocardial infarction, previous cardiac surgery and previous stroke, was similar in subjects with MVP (7.7%) and in those without MVP (6.7%) (P=0.84). The authors concluded that MVP has a much lower prevalence than previously estimated and the prevalence of MVP is similar among different ethnic groups. From a population perspective, the prevalence of serious cardiovascular complications associated with MVP is low.