MITRACLIP VS SURGERY IN PATIENTS WITH ISCHEMIC MITRAL REGURGITATION: A PROPENSITY SCORE ANALYSIS

Abstract

Ischemic mitral regurgitation (IMR) results from adverse left ventricular remodeling after myocardial infarction. Mitral valve (MV) surgery is a common treatment for patients with severe symptomatic IMR. MitraClip, a transcatheter MV repair procedure has also been used for high-risk patients. In this study, we sought to compare postoperative and three-years outcomes of MV surgery and MitraClip in patients with IMR. Retrospective cohort study of patients undergoing surgical (2003-2006) or transcatheter (2010-2016) therapy for severe IMR at the Montréal Heart Institute. Outcomes were compared using Cox regression models including propensity score as an independent variable. 307 patients with IMR were treated: 221 (72%) received conventional MV surgery, while 86 (28%) had MitraClip. The MitraClip cohort was older (p <0.001), had larger ventricular diameters (p <0.001) but had similar ejection fraction as the surgery group (p= 0.297). The adjusted analysis showed that MitraClip had a lower in-hospital mortality (OR 0.05 [0.01-0.31] p=0.001) and lower acute kidney injury (OR 0.13 [0.04-0.39]; P <0.001). There were no differences in postoperative bleeding, or rates of atrial fibrillation. The surgery group had a significantly longer postoperative hospital length of stay (9.50 ± 5.50 vs 4.60 ±2.60 days, p <0.001). At three-year follow-up, MitraClip was associated with a lower mortality (HR 0.45 [0.21-0.86]; p=0.017). There was no difference between the groups for hospitalization for congestive heart failure (HR 1.31 [0.29-5.84]; p= 0.724). Recurrence of MR > 2 was higher in the MitraClip cohort, 27% compared to 4.7% in the surgery group (HR 10.11 [1.24-82.51]; p= 0.031). In this retrospective cohort study of IMR, treatment with MitraClip was associated with lower in-hospital and long-term mortality, lower postoperative complications and a shorter hospital length of stay than conventional MV surgery. At three years there was a higher recurrence of MR > 2 in the MitraClip group but this was not associated with worse NYHA class or hospitalization for heart failure.