Abstract 17575: Left Ventricular Sphericity and Mitral Valve Tenting Area are More Important Predictors of Ischemic Mitral Regurgitation Than Infarct Size and Location: Impact of Revascularization on Ischemic Mitral Regurgitation
BACKGROUND: Ischemic mitral regurgitation (IMR) is a powerful predictor of mortality in patients with advanced ischemic cardiomyopathy (ICM). We sought to assess the association of left ventricular (LV) remodeling, infarct size and location, and mitral valve (MV) geometry with the presence of IMR. In addition, we sought to evaluate the impact of revascularization (revasc) on the severity of IMR in patients referred for viability assessment with cardiac magnetic resonance (CMR).
METHODS: A total of 393 patients with LVEF ≤ 40% and ≥ 70% stenosis in ≥ 1 coronary artery with transthoracic echocardiogram (TTE) and CMR studies within 7 days were included (median=1 day). Patients who underwent MV repair were excluded. CMR was used to quantitatively assess global and regional LV remodeling, scarring and MV geometry. IMR was graded by echocardiography (vena contracta < 0.3cm = mild, 0.3-0.7cm = moderate, < 0.7cm = severe). Patients were followed up with repeat TTE over a mean of 213 ± 72 days. A two-stage regression modeling strategy was used to identify predictors of IMR. A separate model was used to evaluate the change of IMR over time.
RESULTS: Multivariate linear regression analysis revealed that MV tenting area (β 0.136, p<0.001), LV sphericity (β 0.39, p=0.004), age (β 0.004, p=0.001), gender (β 0.84, p=0.001), LV EF (β -0.003, p=0.018), and beta-blocker use (β - 0.85, p=0.003), were independent predictors of MR (r=0.43); while infarct size and location, presence of diabetes, and MV annulus diameter were not. After adjusting for age, gender, LVEF, sphericity, MV annulus diameter, patients who underwent revasc demonstrated early decrease in MR severity, which persisted over time, compared to those who were treated with medical therapy (p=0.001). See Figure.
CONCLUSION: In patients with advanced ICM, MV tenting area and LV sphericity are more predictive of IMR than scar extent and location. Revasc appears to significantly improve MR over time compared to medical therapy.
- © 2013 by American Heart Association, Inc.