Mitral regurgitation in myocardial infarction complicated by heart failure, left ventricular dysfunction, or both: prognostic significance and relation to ventricular size and function

Abstract

Aims: Mitral regurgitation (MR) confers independent risk in patients with acute myocardial infarction. We utilized data from the VALsartan In Acute myocardial iNfarcTion echo study to relate baseline MR to left ventricular (LV) size, shape, and function, and to assess the relationship between baseline MR and progression of MR and cardiovascular (CV) outcomes.

Methods and results: We studied 496 patients with heart failure (HF) and/or systolic dysfunction after MI who underwent echocardiography at a median of 5 days after MI. MR severity, quantified as the regurgitant jet area/left atrial area ratio, was assessed at baseline, one and 20 months post-MI and related to LV size, shape, function, and clinical outcomes. Increased MR at baseline was associated with larger LV end-diastolic and end-systolic volumes, increased sphericity index, and reduced ejection fraction (P trend < 0.001). Moderate-severe MR was an independent predictor of total mortality [adjusted hazard ratio (HR) 2.4 (1.1-5.3)], CV mortality [adjusted HR 2.7 (1.2-6.1)], hospitalization for HF [adjusted HR 2.5 (1.1-5.5)], or death or HF hospitalization [adjusted HR 2.5 (1.4-4.6)]. Patients with progression of MR during the first post-MI month were substantially more likely to die or develop HF (adjusted HR per increased MR grade 3.0, 95% CI 1.8-4.9). Progression of MR over 20 months in survivors was associated with increased hospitalizations for HF (P < 0.001).

Conclusion: Following high-risk myocardial infarction, baseline mitral regurgitant severity is associated with larger LV volumes and worse LV function. Both baseline MR severity and progression of MR are associated with an increased likelihood of adverse outcomes.