1-Year Outcomes From the CLASP IID Randomized Trial for Degenerative Mitral Regurgitation

Background: The CLASP IID (Edwards PASCAL TrAnScatheter Valve RePair System Pivotal Clinical) trial is the first randomized controlled trial comparing the PASCAL system and the MitraClip system in prohibitive risk patients with significant symptomatic degenerative mitral regurgitation (DMR). Objectives: This study sought to report primary and secondary endpoints and 1-year outcomes for the full cohort of the CLASP IID trial. Methods: Prohibitive-risk patients with 3+/4+ DMR were randomized 2:1 (PASCAL:MitraClip). The 1-year assessments included secondary effectiveness endpoints (mitral regurgitation [MR] ≤2+ and MR ≤1+), and clinical, echocardiographic, functional, and quality-of-life outcomes. Primary safety (30-day composite major adverse events [MAEs]) and effectiveness (6-month MR ≤2+) endpoints were assessed for the full cohort. Results: A total of 300 patients were randomized (PASCAL: n = 204; MitraClip: n = 96). At 1 year, differences in survival, freedom from heart failure hospitalization, and MAE were nonsignificant (P > 0.05 for all). Noninferiority of the PASCAL system compared with the MitraClip system persisted for the primary endpoints in the full cohort (for PASCAL vs MitraClip, the 30-day MAE rates were 4.6% vs 5.4% with a rate difference of −0.8% and 95% upper confidence bound of 4.6%. The 6-month MR ≤2+ rates were 97.9% vs 95.7% with a rate difference of 2.2% and 95% lower confidence bound (LCB) of −2.5%, respectively). Noninferiority was met for the secondary effectiveness endpoints at 1 year (MR ≤2+ rates for PASCAL vs MitraClip were 95.8% vs 93.8% with a rate difference of 2.1% and 95% LCB of −4.1%. The MR ≤1+ rates were 77.1% vs 71.3% with a rate difference of 5.8% and 95% LCB of −5.3%, respectively). Significant improvements in functional classification and quality of life were sustained in both groups (P < 0.05 for all vs baseline). Conclusions: The CLASP IID trial full cohort met primary and secondary noninferiority endpoints, and at 1 year, the PASCAL system demonstrated high survival, significant MR reduction, and sustained improvements in functional and quality-of-life outcomes. Results affirm the PASCAL system as a beneficial therapy for prohibitive-surgical-risk patients with significant symptomatic DMR.