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COAPT: MitraClip benefit maintained at 3 years in HF, mitral regurgitation
SAN FRANCISCO — The treatment effect of transcatheter mitral valve repair in patients with HF and moderate-to-severe or severe mitral regurgitation was even greater at 3 years than it was at 2 years, according to new data from the COAPT trial presented at TCT 2019.
In addition, patients assigned medical therapy who crossed over to device therapy (MitraClip, Abbott) did just as well as those who were assigned to transcatheter mitral valve repair at the start of the trial, Michael J. Mack, MD, FACC, medical director of cardiovascular surgery at Baylor Scott and White Health, said during a press conference.
At 3 years, in the intention-to-treat population, the primary outcome of all-cause mortality or HF hospitalization occurred in 88.1% of those assigned guideline-directed medical therapy compared with 58.8% of those assigned device therapy plus guideline-directed medical therapy (HR = 0.48; 95% CI, 0.39-0.58), Mack said.
“The 3-year results were even more dramatic than they were at 2 years,” he said.
The number needed to treat to prevent a first HF hospitalization declined from 4.5 at 2 years to 3.4 at 3 years, according to Mack.
The COAPT researchers also analyzed the 58 patients who crossed over to device therapy from the medical therapy group. Fifty-three crossed over at 2 years in accordance with the study protocol, and five were a protocol deviation and crossed over before 2 years. In this group, the rate of the primary outcome was similar to those who had received device therapy at the start of the trial, Mack said, noting those results may be a case of “survivorship bias.”
Undergoing transcatheter mitral valve repair was an independent predictor of freedom from the primary endpoint at 3 years (HR = 0.43; 95% CI, 0.24-0.78), as was beta-blocker use (HR = 0.57; 95% CI, 0.37-0.88), Mack said at the press conference.
“In patients with heart failure and secondary MR at 36 months, leaflet approximation was safe; provided durable reduction [in MR]; reduced heart failure hospitalizations; and improved survival, quality of life and functional capacity,” Mack said. “Patients who were originally assigned to guideline-directed medical therapy who received the MitraClip had the same results as those patients who were originally assigned to the MitraClip arm.” – by Erik Swain
Reference:
Mack MJ, et al. Late-Breaking Trials 3. Presented at: TCT Scientific Symposium; Sept. 25-29, 2019; San Francisco.
Disclosures: The study was funded by Abbott. Mack reports he consults for W.L. Gore and Associates and serves as study chair or co-principal investigator for trials sponsored by Abbott, Edwards Lifesciences and Medtronic.
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These results were not surprising and were reassuring. It is good that the benefits continue to accrue, but the main message is that the 2-year results were sustained.
The crossover data were very interesting. It was, to me, a good biological experiment. The people who didn’t get the therapy later received it, and ended up doing as well as the people who got it earlier. That’s an internal validation of what the investigators saw. However, the decision of who received subsequent device therapy was not randomized. Perhaps the patients who got it were different from those who did not. They had to survive for 2 years, and many of those who did not cross over died. But there may have been other factors that prompted the investigators to offer the device therapy.
Overall, we do have to be careful about how to interpret these data. The patient population with HF and mitral regurgitation is very large. The group of patients enrolled in COAPT was very well-selected and well-defined. As long as we can find the same phenotype of patients in clinical practice, and are careful about who we implant these clips in, and are able to achieve the same procedural success rates seen in this trial, I think this treatment could be a very good solution for our patients. However, we should be cautious about interpreting these results broadly.
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COAPT data is the gift that keeps on giving. Very important is that the researchers got an opportunity to study in this 3-year follow-up the outcomes of patients that were allowed to cross over at 2 years. The study was rigorously designed and the intention-to-treat protocol was followed vigorously. One thing that was striking is that about 50% of the patients in the guideline-directed medical therapy group were ineligible to cross over because they did or had an additional treatment such as a left ventricular assist device. This was a very sick group of patients with a downward spiral of moderate-to-severe mitral regurgitation and LV dysfunction who were prone to mortality and HF readmissions.
Also important is that the number needed to treat is now even better. This shows the therapy is truly efficacious, even in patients who were initially denied it and then allowed to get it.
Interestingly, all parameters of the outcome aligned themselves to the original COAPT data. This gives us confidence that the efficacy is more than a phenomenon of chance. It is a strong signal with all the point estimates in the same direction.
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