Three-Year COAPT Data Support Abbott's MitraClip TMVR Device

September 28, 2019—The Cardiovascular Research Foundation (CRF) announced that results from the COAPT trial were presented by coprincipal investigator Michael J. Mack, MD, at TCT 2019, the 31st annual Transcatheter Cardiovascular Therapeutics scientific symposium, which is sponsored by CRF and held September 25–29 in San Francisco, California.

COAPT was a randomized, parallel-controlled, open-label multicenter trial evaluating transcatheter mitral valve repair (TMVR) with the MitraClip device (Abbott) in patients with heart failure (HF) and moderate-to-severe or severe secondary mitral regurgitation (MR) who remained symptomatic despite maximally tolerated guideline-directed medical therapy (GDMT) alone.

Between December 2012 and June 2017, a total of 614 patients were enrolled and randomized at 78 centers in the United States and Canada. Per protocol, patients randomized to GDMT were not allowed to crossover to the MitraClip before 24 months but were permitted to do so after 24 months.

The goal of the present study was to describe the 3-year clinical outcomes of patients enrolled in the COAPT trial, including those who crossed over to MitraClip (intention-to-treat) and analyze the impact of MitraClip crossovers in patients assigned to GDMT alone.

According to CRF, the data presented at TCT 2019 showed that the primary effectiveness endpoint of all hospitalizations for HF within 36 months was 220 for the MitraClip plus GDMT arm versus 378 in the GDMT alone arm (hazard ratio [HR], 0.49; 95% confidence interval [CI], 0.37–0.63]; P = .00000006).

The 3-year results from the COAPT trial demonstrated that reducing severe secondary MR with the MitraClip device safely improves prognosis in selected HF patients. In addition, those patients that crossed over and received the MitraClip after 24 months showed the same benefits as those who received the device at the beginning of the study.

The rate of device-related complications at 36 months was 8.7% (1.4% related to the device and 7.4% related to progressive heart failure). All-cause mortality for all patients including crossovers at 3 years was 42.8% for MitraClip plus GDMT compared to 55.5% for GDMT alone (HR, 0.67; 95% CI, 0.52–0.85; P = .001).

Dr. Mack commented in the CRF announcement, “At 36 months, transcatheter mitral leaflet approximation with the MitraClip was safe, provided durable reduction in MR, reduced the rate of HF hospitalizations, and improved survival compared to medical therapy alone,”. “In addition, those patients who crossed over and received a MitraClip experienced fewer HF hospitalizations and deaths or HFHs within 12 months than those who did not crossover, with rates comparable to patients originally assigned to the MitraClip.”

As noted in the CRF announcement, patients with left ventricular dysfunction and HF who develop severe secondary MR have a poor prognosis with high rates of mortality and HF hospitalizations. GDMT, including cardiac resynchronization therapy, if appropriate, has been the traditional therapy for all such patients. In the procedure evaluated in COAPT, the MitraClip device is attached to the mitral valve leaflets via a catheter that is then removed, leaving the clipped valve in place with less regurgitation. At TCT 2018, Gregg W. Stone, MD, presented the 2-year COAPT data, which were also published by Dr. Stone et al in The New England Journal of Medicine (2018;379:2307–2318}.