Left Ventricular Stroke Work Index Associated With Outcome After Mitral Valve Surgery for Functional Regurgitation in Nonischemic Dilated Cardiomyopathy.

The indications for mitral valve surgery in patients with advanced nonischemic dilated cardiomyopathy and functional mitral regurgitation are still unclear. We reviewed our experience of mitral valve surgery in such patients and explored factors that were predictive of outcomes. Fifty-three consecutive patients with nonischemic dilated cardiomyopathy and an ejection fraction <35% who underwent mitral valve surgery were reviewed. Thirty five patients (66%) suffered all-cause death or underwent admission for heart failure or left ventricular assist device implantation after mitral valve surgery during follow-up (37 ± 27 months); freedom from these events at 3 years was 45%. Mitral valve surgery significantly reduced left ventricular volume (P < 0.01) and pulmonary vascular resistance (P < 0.01) in survivors. New York Heart Association functional class also improved significantly (P < 0.01) at 1 year after surgery. By multivariate analysis, preoperative left ventricular stroke work index (P < 0.04) was the sole significant predictor of composite outcomes including all-cause mortality, admission for heart failure or left ventricular assist device implantation after mitral valve surgery, with a cut-off value of 25.9 g-m/m2/beat. A higher tethering height (≥11 mm, P < 0.01) was a significant predictive factor for mitral regurgitation recurrence (P = 0.02). Mitral valve surgery for significant functional mitral regurgitation associated with nonischemic cardiomyopathy is still challenging. However, thorough hemodynamic investigations prior to surgery could provide useful indications regarding mitral valve surgery in these patients, contributing to an improvement in their clinical outcomes.