Early mitral regurgitation after acute myocardial infarction does not contribute to subsequent left ventricular remodeling

BACKGROUND: It is well known that mitral regurgitation may lead to left ventricular dilation; however, the relationship between progressive left ventricular dilation after acute myocardial infarction (MI) and mitral regurgitation has not yet been clarified. HYPOTHESIS: This study tested the hypothesis that early mitral regurgitation contributes to left ventricular remodeling after acute MI. METHODS: We prospectively evaluated 131 consecutive patients by serial two-dimensional and Doppler echocardiography on Days 1, 2, 3, and 7, after 3 and 6 weeks, 3 and 6 months, and 1 year following acute MI. Patients were divided into two groups: those with mitral regurgitation in the first week after acute MI (Group 1, n = 34) and those without mitral regurgitation (Group 2, n = 81). RESULTS: Over 1 year, a significant increase in end-diastolic volume index (from 62.1 +/- 12.9 to 70.5 +/- 23.6 ml/m2, p = 0.001) with a strong linear trend (F = 15.1, p < 0.001) was noted. Initial end-diastolic volume index was higher in Group 1 (65.6 +/- 13.3 vs. 60.4 +/- 12.5 ml/m2, p = 0.047), but this difference remained constant throughout the study (F = 1.76, p = NS). Therefore, the pattern of end-diastolic volume changes was similar in both groups during the period of observation. CONCLUSIONS: These data indicate that early mitral regurgitation after acute MI does not contribute to subsequent left ventricular remodeling in the first year after myocardial infarction.