PARIS — The clinical benefit seen with the MitraClip (Abbott) in patients with heart failure (HF) compared with guideline-directed medical therapy (GDMT) in the COAPT trial may be due the associated greater reductions in mitral regurgitation (MR) with the percutaneous MR repair device, a new analysis of COAPT data suggest.
But however they got there — MitraClip or meds alone — it was clear that patients with lower residual MR (≤2+) at 30 days had lower rates at 2 years of HF hospitalization and all-cause mortality and improved quality of life compared with patients with residual MR of 3+ or 4+, and that there were no significant differences in major events between the two lower residual MR strata, reported Saibal Kar, MD, from Cedars-Sinai Medical Center, Los Angeles, on behalf of COAPT investigators.
“While some patients with just guideline-directed medical treatment improved MR at 30 days, many of these patients later had recurrent severe MR. The improvement achieved at 30 days with the MitraClip, on the other hand, was significantly more durable over the next 2 years,” he said here at the Congress of the European Association of Percutaneous Cardiovascular Interventions (EuroPCR 2019)
MR in COAPT
Kar presented results of an analysis evaluating the durability and impact of the degree of residual MR at 30 days on long-term clinical and functional outcomes in both the MitraClip and control (GDMT) groups of COAPT.
An analysis of time to first HF hospitalization or all-cause mortality at 2 years showed that 73.5% of patients who had MR 3+/4+ at 30 days on study had died or were admitted for HF, compared with 49.8% of those with MR 2+ at 30 days, and 38.6% of those with MR 0/1+ (P for overall comparison < .001).
The hazard ratio (HR) for the difference between the lower two categories was not statistically significant, but the differences between MR 0/1+ and MR 3+/4+ and between MR 2+ and the highest residual MR category were both significant (HR, 0.38 and 0.50; P < .001, respectively).
In both the MitraClip-plus-GDMT group and the GDMT-alone group, there were no significant differences for either end point between the lowest two strata of residual MR, but a significant difference between each of two lower groups and the highest residual MR group. In both clip/drug and drug-alone groups, approximately 73% of patients with 3+/4+ MR at 30 days had an event by 2 years, compared with approximately 50% of patients with MR 2+ at 30 days, and about 40% of those with MR 0/1+ 30 days out.
Similarly, the cumulative HF hospitalization rate at 2 years was 82.4% in the highest residual MR category, compared with 34.1% in the intermediate (2+) group, and 32% in the lowest residual MR group. The respective cumulative all-cause mortality rates were 48.4%, 32.1%, and 23.7%, respectively. Here too, the hazard ratios were not significant between the two lowest categories of residual MR, but were significant for the difference between each of the lower two strata and the highest strata.
Looking at Kansas City Cardiomyopathy Questionnaire (KCCQ) quality-of-life scores at 12 months stratified by 30-day MR, the investigators found that in the pooled population, MitraClip/GDMT, and GDMT-alone groups, residual 30-day MR 3+/4+ was associated with significantly lower quality-of-life improvements.
Among the subgroup of patients with 30-day residual MR ≤1+, MR severity remained stable over 2 years among all patients treated with the MitraClip plus GDMT, whereas 30.8% of patients in the GDMT-alone group had reverted to MR >2+.
By Any Means Necessary
Invited discussant Nina Wunderlich, MD, Cardiovascular Center Darmstadt, Germany, commented that the COAPT data “emphasize just how important it is to achieve a mitral regurgitation grade which less than 2+, and this can be done either with MitraClip or optimal medical therapy.”
“But if we compare these two strategies, we can reach this goal in about 93% with the MitraClip, but only in about 34% in the patient group that is treated medically,” she said.
The findings suggest that for patients with HF and moderate to severe MR who meet the COAPT eligibility criteria, “MitraClip could be the new standard of care, provided that patients are at the optimal medical therapy and that MitraClip results are good, and this means that we have to do any effort to lower the degree of mitral regurgitation to less than 2+,” she said.
PCR/EAPCI Weigh In
Although the overall COAPT findings were in direct contrast to those of MITRA-FR, which found that at 1 year, there was absolutely no difference in the primary composite end point of all-cause death and unplanned hospitalization for HF between the MitraClip and medical-therapy-alone groups, there were key differences in the trials and there is good evidence to support the use of the MitraClip in select patients, noted Bernard Prendergast, MD, from St. Thomas’ Hospital, London.
Following Kar’s presentation, Prendergast outlined a joint statement from PCR and the European Association of Percutaneous Cardiovascular Interventions (EAPCI) on percutaneous edge-to-edge repair in patients with HF and secondary MR.
“Mitral regurgitation is dangerous, with an ominous prognosis regardless of underlying left ventricular function,” he said.
The statement says, in part, that patients with HF and moderate to severe MR should be referred early to a multidisciplinary heart team, including HF specialists, valve interventionists, valve surgeons, valve imaging specialists, and electrophysiologists.
The team should evaluate and optimize medical therapy for these patients and consider the use of CRT or other device therapy, transcatheter mitral interventions, and surgery.
The statement also says that “transcatheter edge-to-edge repair is appropriate in carefully selected patients who remain symptomatic despite optimal medical therapy (including CRT). This group may include patients with severe secondary MR, defined as an effective regurgitant orifice area ≥30 mm2, regurgitant volume ≥45 mL, or regurgitant fraction ≥50%; suitable valve morphology, left ventricular end-systolic dimension below 70, and absence of significant right ventricular dysfunction, tricuspid regurgitation, and pulmonary hypertension.
COAPT was funded by Abbott. Kar disclosed grant/research supports and consulting fees/honoraria from Abbott Vascular and others. Wunderlich reported having unspecified financial relationships. Prendergast reported a relationship with Edwards Lifesciences.
Congress of the European Association of Percutaneous Cardiovascular Interventions (EuroPCR) 2019. Presented May 21, 2019.