Abstract 13513: MitraClip ^® for Functional Mitral Regurgitation: Outcomes in Over 600 Patients

Background: The treatment options for degenerative or primary mitral regurgitation (DMR) include mitral surgery and transcatheter edge-to-edge repair (MitraClip). However, the optimal therapy for patients with functional or secondary MR (FMR) remains unclear. The purpose of this study was to evaluate the 1 year outcomes of all patients with FMR undergoing MitraClip in the United States as part of the EVEREST (Endovascular Valve Edge-to-Edge Repair STudy) II study. Methods: Patients treated in the EVEREST II trial (randomized trial and continued access registries) with severe FMR were evaluated. Outcomes at 30 days and 1 year were analyzed and adjudicated by an independent core laboratory. Patients were further stratified by surgical risk (High risk= STS mortality score ≥12% or pre-specified risk factors). Results: A total of 619 patients (mean age=73.4 years) with FMR were treated with MitraClip. Comorbidities were common including coronary artery disease (81.1%), NYHA functional class III/IV (80.3%), and previous coronary artery bypass grafting (55.7%). Device implantation was achieved in 96.4% with a mean hospital stay of 3.3 days and an 87.2% discharge to home. At 30 days, mortality was 3.6% with a major adverse event rate of 9.2%. At 1 year, the survival was 78.3%, while the majority of survivors had MR≤2+ (84.5%) and significantly improved symptoms (83.2% NYHA Class I/II). The left ventricular end diastolic volume (LVEDV) improved from 162.5ml to 152.6ml (P<.001). When comparing high surgical risk patients (n=485; mean STS score=10.6±6.9%) to non-high risk patients (n=134), the 30 day mortality was similar (4.1% vs. 1.5%, P=.19), but the 1 year mortality was worse (22.7% vs. 13.4%, P=.02). Nevertheless, at 1 year, there were similar rates of MR reduction (MR≤2+: 83.9% vs. 87.3%) and improvement in LVEDV (-9.0ml vs -12.6ml). The non-high risk cases had greater symptom improvement (NYHA Class I/II: 91.2% vs. 80.2%, P=.001). Conclusions: MitraClip in patients with severe FMR is associated with excellent safety, positive ventricular remodeling, symptom improvement, and stable MR reduction at 1 year independent of surgical risk. Compared to high surgical risk patients, non-high risk patients may derive the greatest survival and symptom benefit.