Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation - COAPT
Dharam J. Kumbhani
Study Design
Patients with HF and grade 3-4+ MR who remained symptomatic despite maximally tolerated guideline-directed medical therapy (GDMT) were randomized to MitraClip + GDMT (n = 302) vs. GDMT alone (n = 312). This trial had an open-label design.
Inclusion criteria
Exclusion criteria
Other salient features/characteristics
Principal Findings
The primary effectiveness endpoint, HF hospitalization at 24 months for MitraClip + GDMT vs. GDMT, was 35.8% vs. 67.9% (hazard ratio [HR] 0.53, 95% confidence interval [CI] 0.40-0.70, p < 0.001). The primary safety endpoint, freedom from device-related complications at 12 months, was 96.6% for MitraClip (p < 0.001).
Secondary outcomes for MitraClip + GDMT vs. GDMT
Quality-of-life (QoL) subanalysis
Mean Kansas City Cardiomyopathy Questionnaire (KCCQ)-OS (overall summary) at baseline for MitraClip + GDMT vs. GDMT: 53.2 vs. 51.6; mean KCCQ-QoL: 45.2 vs. 44.7
Three-year outcomes
At 2 years, patients in the GDMT arm could cross over to the MitraClip arm if needed. As a result, total crossover was 18.6% (majority between 2 and 3 years). For the primary results, on ITT, there was still a profound benefit of MitraClip + GDMT over GDMT (annualized rates 35.5% vs. 68.8%, HR 0.49, 95% CI 0.37-0.63, p < 0.001). Benefit of MitraClip on mortality was preserved (42.8% vs. 55.5%, p = 0.001). Among the MitraClip patients, progressive HF requiring LVAD or heart transplant occurred in an additional 3.6% of patients (total 7.4%). Among the patients who crossed over, first HF hospitalization at 1 year was lower (13.8%), and the curves for the other clinical endpoints were more similar to the MitraClip arm than to the GDMT only arm, suggesting that benefit noted for the original MitraClip arm could be replicated in the control arm with MitraClip implantation (crossover).
Interpretation of the COAPT Trial
The results of this landmark trial indicate that transcatheter mitral valve approximation using the MitraClip on a background of maximally tolerated GDMT was superior to GDMT alone in reducing HF hospitalization and mortality in symptomatic HF patients with grade 3-4+ MR. Improvements were also observed in LV dimensions and patient symptoms. Significant improvements were noted in QoL measurements starting at 1 month and sustained out to 24 months. The device had excellent safety.
All operators in this trial were experienced in the use of MitraClip. These results come on the heels of the recently published MITRA-FR trial, which did not show a benefit in this patient population. Possible reasons for differences include enrollment of patients with more severe MR (EROA >30 in COAPT vs. >20 in MITRA-FR) and less dilated ventricles (LVEDV 101 vs. 135, respectively). Procedural complications and success in reducing MR were also higher in the COAPT trial. These are truly landmark findings and will likely have a significant impact on the management of patients with secondary MR.
References
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