In the CLASP* IID trial, the PASCAL Transcatheter Valve Repair System demonstrated noninferiority to the MitraClip System for the treatment of severe symptomatic degenerative mitral regurgitation (DMR).
“[Our trial is] the first randomized controlled trial to directly compare two contemporary M-TEER** therapies [for] significant symptomatic DMR, [which] has a poor prognosis in the absence of treatment,” said the researchers. “[Our trial] met its noninferiority endpoints.”
The study included 180 individuals (mean age 81 years, 68 percent male) with DMR 3+ or 4+ at prohibitive risk for mitral valve surgery. They were randomized 2:1 to either the PASCAL or the MitraClip system.
Safety, efficacy outcomes
At 30 days, the composite major adverse event rates were 3.4 percent and 4.8 percent for PASCAL and MitraClip, respectively. “[There was] an absolute difference of 1.3 percent and a one-sided 95 percent upper confidence bound of 5.1 percent, which is well within the prespecified noninferiority margin of 15 percent,” said Dr Scott Lim from the University of Virginia, Charlottesville, Virginia, USĀ, at TCT 2022.
Survival rates with PASCAL were similar at 30 days (98 percent) and 6 months (95 percent), as were the rates of heart failure hospitalization (HFH; 100 percent and 98 percent, respectively). A similar trend was seen with MitraClip at both the 30-day (98 percent for both survival and HFH) and 6-month timepoints (94 percent and 97 percent). “The Kaplan-Meier curves for freedom from all-cause mortality and HFH or the combination of both mirrored each other in both arms,” Lim said.
“A significant percentage of [participants] had MR 4+ at baseline,” noted Lim. By month 6, almost all participants in the PASCAL and MitraClip arms achieved MR ≤2+ (96 percent and 97 percent, respectively). The MR reductions in both arms were already evident by discharge and at 30 days.
In the PASCAL arm, MR ≤1+ was sustained from discharge (87 percent) to 6 months (84 percent), implying MR ≤1+ durability, noted study co-author Dr Konstantinos Koulogiannis from the Atlantic Health System Morristown Medical Center, Morristown, New Jersey, US, who further discussed the echocardiographic outcomes. With MitraClip, there was some degradation in the fraction of participants having MR ≤1+ from baseline to 6 months (from 88 percent to 71 percent).
Functional, quality-of-life outcomes
At baseline, more than half of participants were under NYHA*** functional class III (56 percent [PASCAL] and 54 percent [MitraClip]). By month 6, most have transitioned to NYHA functional class I/II (86 percent and 95 percent, respectively).
Six-minute walk distance also improved from baseline to 6 months with both PASCAL (from 258 to 282 m; p=0.027) and MitraClip (from 261 to 301 m; p=0.016).
Month 6 also saw marked improvements in both arms from baseline KCCQ# Overall Score (from 56 to 74 points [PASCAL] and 59 to 79 points [MitraClip]; p<0.001 for both) and EQ-5D-5L## Health Score (from 62 to 72 points; p<0.001 and 65 to 74 points; p=0.031, respectively).
“These findings translate to significant improvements in functional capacity and physiologic performance … in both arms,” said Lim.
Beneficial for symptomatic DMR
“[Overall, our study] further establishes the safety and effectiveness of M-TEER for prohibitive risk DMR patients,” said Lim. “The excellent safety and efficacy outcomes in both arms are indicative of the tremendous improvements in contemporary M-TEER technology, as well as operator skill and experience.”
“The PASCAL system is a beneficial therapy for significant symptomatic DMR, expanding transcatheter treatment options for prohibitive surgical risk patients,” Lim concluded. Continued follow-up to 5 years shall validate long-term outcomes for both systems.