Randomized Comparison of Transcatheter Edge-to-Edge Repair for Degenerative Mitral Regurgitation in Prohibitive Surgical Risk Patients

Severe symptomatic degenerative mitral regurgitation (DMR) has a poor prognosis in the absence of treatment, and new transcatheter options are emerging.The CLASP IID (Edwards PASCAL Transcatheter Valve Repair System Pivotal Clinical Trial) randomized trial (NCT03706833) is the first to evaluate the safety and effectiveness of the PASCAL system compared with the MitraClip system in patients with significant symptomatic DMR. This report presents the primary safety and effectiveness endpoints for the trial.Patients with 3+ or 4+ DMR at prohibitive surgical risk were assessed by a central screening committee and randomized 2:1 (PASCAL:MitraClip). Study oversight also included an echocardiography core laboratory and a clinical events committee. The primary safety endpoint was the composite major adverse event rate at 30 days. The primary effectiveness endpoint was the proportion of patients with mitral regurgitation (MR) ≤2+ at 6 months.A prespecified interim analysis in 180 patients demonstrated noninferiority of the PASCAL system vs the MitraClip system for the primary safety and effectiveness endpoints of major adverse event rate (3.4% vs 4.8%) and MR ≤2+ (96.5% vs 96.8%), respectively. Functional and quality-of-life outcomes significantly improved in both groups (P < 0.05). The proportion of patients with MR ≤1+ was durable in the PASCAL group from discharge to 6 months (PASCAL, 87.2% and 83.7% [P = 0.317 vs discharge]; MitraClip, 88.5% and 71.2% [P = 0.003 vs discharge]).The CLASP IID trial demonstrated safety and effectiveness of the PASCAL system and met noninferiority endpoints, expanding transcatheter treatment options for prohibitive surgical risk patients with significant symptomatic DMR.