To analyze the evolution of mitral regurgitation (MR) after the diagnosis of mitral valve prolapse in community patients, 285 residents of Olmsted County, Minnesota, diagnosed with mitral valve prolapse without severe MR were studied. MR grade was assessed at diagnosis and at follow-up 1,663 +/- 1,079 days later using Doppler echocardiography. The progression of MR was defined as an increase of > or =1 MR grade. The patients' mean age was 56 +/- 22 years, 57% were women, and the mean ejection fraction was 60 +/- 9%. Between diagnostic and follow-up echocardiography, 108 patients showed progression of MR, 39 of whom had progression > or =1 grade. The mean overall MR grade increased from 0.4 +/- 0.7 to 0.9 +/- 1.1 (p <0.01). The progression of MR was observed in all subsets, irrespective of age, gender, prolapse localization, leaflet thickening, and initial MR grade. However, multivariate analysis identified age (p <0.01) and initial MR grade (p = 0.01) as independent predictors of progression. In addition, MR progression was associated with greater left atrial enlargement (p <0.001), ventricular dilatation (p = 0.02 for increase in end-diastolic and end-systolic diameters), and a worse outcome (adjusted p = 0.001). In conclusion, in patients with mitral valve prolapse, MR progression was observed over time in all clinical and anatomic subsets and was associated with more severe ventricular and atrial remodeling and worse outcome.