Three-dimensional echocardiography-derived vena contracta area at rest and its increase during exercise predicts clinical outcome in mild-moderate functional mitral regurgitation

Abstract

Background: This study assessed the independent significance of color Doppler 3-D vena contracta area (VCA) at rest and during exercise as a predictor of clinical outcome in mild-moderate functional mitral regurgitation (FMR). METHODS AND RESULTS: The subjects consisted of 62 patients (age, 68±11 years; 76% male) with chronic systolic heart failure and mild-moderate FMR (<2+/4) at rest. All patients underwent VCA assessment at rest and during semi-supine bicycle exercise. During median follow-up of 17 months (IQR, 13-20 months), 15 patients (24%) had composite endpoint of all-cause death (n=3), heart failure admission (n=11), and heart transplantation (n=1). At baseline, patients with vs. without endpoint had significantly larger VCA at rest (17±6 mm(2)vs. 13±7 mm(2), P=0.002) and at peak exercise (35±16 mm(2)vs. 21±12 mm(2), P<0.001). On Cox regression analysis, large (≥15-mm(2)) resting VCA (HR, 7.6; 95% CI: 1.93-13.02; P=0.004) and large (≥20-mm(2)) exercise-induced increase of VCA (HR, 5.1; 95% CI: 1.39-15.21; P=0.014) were independently associated with composite endpoint. Concomitant presence of large VCA at rest and its large increase during exercise occurred in 53% of patients with, vs. in only 8% without, endpoint (negative predictive value, 86%).

Conclusions: The presence of relatively large VCA at rest and its significant increase during exercise is independently associated with adverse clinical outcome in patients with mild-moderate FMR at rest.