oa Functional Mitral Regurgitation Is a Main Determinant Of Adverse Outcome In Patients With Heart Failure Due To Non-Ischemic Dilated Cardiomyopathy.

Ischemic mitral regurgitation has been recently demonstrated to carry important prognostic information in patients with left ventricular dysfunction due to coronary artery disease. There is no information regarding the prognostic role of functional mitral regurgitation in patients with non ischemic dilated cardiomyopathy. Patients with stable heart failure due to non-ischemic dilated cardiomyopathy were prospectively enrolled. All patients underwent a comprehensive echocardiographic assessment. Left ventricular diastolic (LVD) , systolic (LVS) diameters, left atrial diameter (LAD), ejection fraction (EF) and restrictive mitral filling pattern (RMP) was measured. Mitral regurgitant volume (RV) was measured by means of proximal isovelocity surface area method. The end point of the study was death or hospitalization for worsening heart failure. 80 patients (mean age 61±9 years; 82% male) were enrolled. 10 patients reached the end point of the study. At univariate Cox analysis, the echocardiographic variables associated with outcome were: EF (HR 0.84 95% CI 0.75 0.94; p=0.002), RMP (HR 5.2 95% CI 1.4 19.7; p=0.01) and RV (HR 1.046 95% CI 1.02 1.07; p=0.0005), LVS/BSA (HR 1.2 95% CI 1.02 1.4; p=0.03). At multivariate analysis RV remained the only variables independently associated with outcome (p=0.04). Result did not change when LVS/BSA substituted EF in the model. Receiving operator characteristics analysis documented that the area under the curve for RV in identifying patients with adverse outcome was 0.84±0.06 (95% CI 0.74 0.91) and the best cut off value for RV was 28 ml (sensitivity 80% 95% CI 44 97 and specificity 87% 95% CI 77 94). Patients with RV<28 had a survival rate of 95% after 6 years from the index echocardiogram compared with 22% in those with RV> 28 (longrank 23; p<0.0001). In patients with non-ischemic dilated cardiomyopathy, RV was a main predictor of death or hospitalization for worsening heart failure.