Left ventricular remodeling is associated with the severity of mitral regurgitation after inaugural anterior myocardial infarction—Optimal timing for echocardiographic imaging

Background Although mitral regurgitation (MR) has been associated with an increased risk of death and heart failure after myocardial infarction (MI), the relationship between post-MI MR and left ventricular (LV) remodeling has not been entirely clarified. In addition, the optimal timing for assessing MR after MI remains unknown. Methods Post-MI MR was assessed by Doppler echocardiography at hospital discharge (baseline) and after 3 months in 261 patients with an inaugural anterior MI. We studied LV remodeling during a 1-year period and clinical follow-up after 3 years, according to MR severity at baseline and at 3 months. Results Left ventricular remodeling was demonstrated as an increase in LV end-diastolic volume from 56 ± 15 mL/m2 at baseline to 63 ± 19 mL/m2 at 1 year ( P < .0001). MR severity at baseline was not significantly associated with LV remodeling. By contrast, MR severity at 3 months was a strong indicator of LV remodeling. There was a graded increase in the proportion of patients with a >20% increase in LV end-diastolic volume between baseline and 1 year according to MR severity at 3 months (no MR: 21%, mild MR: 32%, moderate/severe MR: 60%) ( P = .008). Both MR at baseline and at 3 months were associated with death or rehospitalization for heart failure by univariate analysis ( P = .014 and P < .0001, respectively). By multivariable analysis, MR at baseline was not an independent predictor of adverse outcome ( P = .66). By contrast, MR at 3 months was independently associated with adverse outcome with a hazard ratio of 2.23 (1.02-4.91 [ P = .04]). Conclusions After an inaugural anterior MI, MR is associated with LV remodeling and adverse clinical outcome. For prognostic purpose, the optimal timing for assessing MR is the chronic post-MI stage rather than the early post-MI period.