COAPT: Patients with HF, mitral regurgitation see better health outcomes with TMVR

A recent analysis of the COAPT trial, published this spring in the Journal of the American College of Cardiology, suggests patients with symptomatic heart failure (HF) and secondary mitral regurgitation (MR) might see better mental and physical outcomes if they’re treated with edge-to-edge transcatheter mitral valve repair (TMVR) in lieu of standard therapy.

The COAPT study, first presented at TCT 2018 in San Diego, is renowned for proving the efficacy of Abbott’s MitraClip, an MR therapy that “clips” a patient’s valve leaflets together to reduce the backflow of blood into the heart. TMVR using the MitraClip was initially approved in the U.S. as an alternative to open-heart surgery in high-risk patients with primary MR, but COAPT found those benefits extended to patients with HF and secondary MR, as well.

“Beyond prolonging survival and reducing hospitalizations, improving patients’ health status (i.e. symptoms, functional status, quality of life) is a key treatment goal of TMVR,” first author Suzanne V. Arnold, MD, MHA, of the University of Missouri-Kansas City, and colleagues wrote in the latest analysis. “In fact, among older patients with comorbidities and high symptom burden, health status improvement may be of greater importance to patients than improved survival.”

Arnold and her team randomized 614 subjects with HF and 3+ to 4+ secondary MR to treatment with either TMVR (302 patients) or standard care (312 patients). Health status was assessed at the study’s baseline and at 1, 6, 12 and 24 months using the SF-36 health status survey and the Kansas City Cardiomyopathy Questionnaire (KCCS), a measure of a patient’s self-perception of their health status.

The KCCQ operates on a sliding scale, where an outcome of 100 indicates the best possible result, an outcome of 0 represents the worst possible result and a clinically important difference is defined by 5 points or more. At the baseline of the COAPT trial patients had a mean overall KCCQ of 52.4, suggesting substantially impaired health status.

Arnold et al. found that while health status was relatively unchanged over time in the standard care cohort, patients randomized to TMVR saw an average 15.9-point hike in their KCCQ score at one month. The average between-group difference in scores was 12.8 points at 24 months.

At two years, the authors said 36.4% of TMVR patients were alive and substantially improved, compared to 16.6% of standard care patients. TMVR patients also reported better generic health status at each timepoint, including a 24-month mean difference of 3.6 points in physical SF-36 scores and a difference of 6.4 points in mental SF-36 scores.

“Health status, as assessed by KCCQ-OR and SF-36, improved as soon as during the first month after TMVR, which argues in favor of an effect of the correction of MR,” Bernard Iung and David Messika-Zeitoun wrote in a related JACC editorial. “There was also an improvement of health status in the standard care arm, although of small extent, and this is a further illustration of the need for randomized controlled trials for assessing the therapeutic efficacy of the treatment of secondary MR where confounding factors are particularly numerous.”

Iung and Messika-Zeitoun said it’s still tough to discern which HF and MR patients are the best candidates for TMVR, and which procedures would be futile. They said that moving forward, it will be imperative for physicians to define selection criteria in a more structured way.

“The identification of futile procedures remains difficult in current practice,” the editorialists wrote. “In the present analysis, the improvement in health status after TMVR, as compared with standard care, was consistent across all pre-specified subgroups and it is therefore not possible to identify easily the patient characteristics associated with a high risk of performance of a futile procedure.”