Transcatheter edge-to-edge repair of functional mitral regurgitation in heart failure: Final five-year results from the COAPT Trial

Dr. Bilal Ülker

Published in congress: ACC 2023

Objective:
 In 2018, the first results of the COAPT trial randomizing patients with heart failure with low ejection fraction and moderate-to-severe or severe (3+/4+) mitral regurgitation (MR) to transcatheter repair with MitraClip (M-TEER) or medical therapy were presented.
Following the demonstration that M-TEER resulted in a significant reduction in heart failure hospitalizations and mortality after 24 months of follow-up, M-TEER was recommended by the ESC/EACTS guidelines as class IIa in eligible patients. This study evaluated the efficacy of MR reduction achieved with M-TEER and its impact on clinical endpoints.

Methods:
The COAPT study included 614 patients with moderate to advanced (3+) or severe (4+) secondary MR who were symptomatic despite optimal GDMT. Patients were diagnosed with non-ischemic or ischemic cardiomyopathy, had LVEFs between 20-50% and NYHA class II-IV. The primary efficacy endpoint was hospitalizations for heart failure and secondary endpoints were death from any cause and MR reduction.

Results:
 In the study, 614 patients were divided into M-TEER (n=302) or GDMT only (n=312) groups. The mean age of patients was 72 years, 43% of M-TEER patients and 48% of GDMT patients were female. The mean STS score for the risk of surgical mortality was 8% and approximately 60% were NYHA class III/IV. All-cause hospitalizations for heart failure at 5 years, the primary endpoint, were significantly reduced in the group of patients who underwent M-TEER (HR: 0.53 [0.41-0.68]). All-cause mortality was high in both groups (67% in the GDMT group and 57% in the M-TEER group) but was significantly reduced in M-TEER patients (HR: 0.72 [0.58-0.89]). MR reduction was maintained with 94.7% in the device group with MR ≤ 2+ at 5 years. In patients who switched from GDMT to M-TEER after 2 years, outcomes in the first 3 years after treatment were similar to patients who underwent M-TEER at the start of the study.

Discussion:
The fact that the favorable results obtained in previous follow-ups in terms of heart failure hospitalizations and mortality were maintained over this long period of time can be considered promising for the future. Moreover, seems to be highly effective with more than 90% of patients who underwent M-TEER still having MR ≤ 2+ at 5 years. Nevertheless, the very high rate of hospitalizations and mortality due to heart failure emphasizes the seriousness of the underlying disease. This probably means that:
a) heart failure and secondary MR patients who are symptomatic despite optimized GDMT and eligible for M-TEER should receive interventional therapy as early as possible.
b) additional studies investigating the impact of earlier treatment with M-TEER on prognosis in this patient group are warranted.
Taken together, these latest 5-year results of the COAPT trial provide an encouraging message that M-TEER with MitraClip significantly reduces heart failure hospitalization and mortality in heart failure patients with severe secondary MR.