Functional MR Transcatheter Edge-to-Edge Repair Outcomes

Quick Takes

  • Using registry data from EuroSMR, the application of COAPT eligibility criteria was associated with lower 2-year all-cause mortality among COAPT-eligible compared to COAPT-ineligible patients, whereas 2-year mortality was comparable when patients were stratified using MITRA-FR eligibility criteria.
  • These data support that differences in study inclusion criteria could have contributed to disparate mortality outcomes in the COAPT and MITRA-FR trials.
  • Among a subset of patients who underwent functional assessment with 6-minute walk test and/or MLHFQ, functional status appeared to improve regardless of COAPT eligibility criteria.

Study Questions:

How do selection criteria influence outcomes for transcatheter edge-to-edge repair (TEER) among patients with functional mitral regurgitation (FMR)?

Methods:

The EuroSMR (European Registry of Transcatheter Repair for Secondary Mitral Regurgitation) registry includes anonymized data for patients with FMR treated with TEER at 11 high-volume centers in France, Switzerland, Italy, Portugal, and Germany. Specific selection criteria for the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation) and for the MITRA-FR (Percutaneous Repair or Medical Treatment for Secondary Mitral Regurgitation) trials were used to retrospectively stratify registry patients. A total of 1,022 registry patients treated from November 2008 to September 2019 were stratified to COAPT-eligible (n = 353 [34.5%]) and COAPT-ineligible (n = 669 [65.5%]), and to MITRA-FR-eligible (n = 408 [48.3%]) and MITRAL-FR-ineligible (437 [51.7%]). The primary study endpoint was all-cause mortality censored after 2-year follow-up. Change in functional status also was assessed for a subset of patients who had undergone 6-minute walk test and/or Minnesota Living With Heart Failure Questionnaire (MLHFQ).

Results:

The 2-year all-cause mortality was similar among MITRA-FR-eligible (31.8%) and MITRA-FR-ineligible patients (36.8%, p = 0.19). However, stratification of patients according to COAPT criteria revealed lower 2-year mortality rates among COAPT-eligible (25.2%) compared with COAPT-ineligible patients (38.2%, p < 0.001). Multivariable Cox regression analysis identified New York Heart Association functional class IV (hazard ratio [HR], 2.29; 95% confidence interval [CI], 1.53-3.42; p < 0.001), logarithmic N-terminal pro–B-type natriuretic peptide (HR, 1.47; 95% CI, 1.24-1.75; p < 0.001), and right ventricular-to-pulmonary arterial coupling (HR, 0.10; 95% CI, 0.02-0.57; p = 0.009) as independent predictors of outcome. Improvement in functional status was demonstrated in a subset of patients irrespective of COAPT eligibility; with increased 6-minute walk distance after 6 weeks or latest follow-up (COAPT-eligible [n = 78] median ∆ +14 m [p = 0.0047] and COAPT-ineligible [p = 120] median ∆ +57 m [p < 0.001]), and reduction in MLHFQ score (COAPT-eligible [n = 116] median ∆ -19.0 [p < 0.001] and COAPT-ineligible [p = 157] median ∆ -11.0 [p < 0.001]).

Conclusions:

Using registry data for patients who underwent TEER for FMR, the retrospective application of COAPT enrollment criteria identified a specific phenotype with lower 2-year mortality rates, whereas stratification using MITRA-FR criteria yielded comparable mortality outcomes.

Perspective:

The COAPT trial demonstrated improved survival among patients with FMR treated with TEER in addition to guideline-directed medical therapy, whereas the MITRA-FR trial showed no survival benefit associated with TEER for treatment of FMR. There were important differences in trial designs and inclusion criteria, resulting in inclusion in the COAPT trial of patients with relatively greater severity of FMR and lesser degrees of left ventricular dilation, leading to a theory that patient characteristics might have been a contributing factor to the disparate trial outcomes. Although subsequent reanalysis of data from the MITRA-FR and COAPT trials failed to confirm that the concept of proportionate versus disproportionate FMR (and the effective regurgitant orifice area-to-left ventricular end-diastolic volume ratio) could explain the differences in study outcomes, retrospective analysis of these registry data suggests that differences in trial inclusion criteria could be contributory to mortality outcomes. Although data were available in only a modest subset or registry patients, the finding in this study that functional status appeared to improve regardless of COAPT eligibility criteria could support the consideration for TEER among some patients with FMR even in the absence of anticipated mortality benefit.

Clinical Topics: Cardiac Surgery, Cardiovascular Care Team, Geriatric Cardiology, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Pulmonary Hypertension and Venous Thromboembolism, Valvular Heart Disease, Cardiac Surgery and Heart Failure, Cardiac Surgery and VHD, Acute Heart Failure, Heart Failure and Cardiac Biomarkers, Pulmonary Hypertension, Interventions and Structural Heart Disease, Mitral Regurgitation

Keywords: Dilatation, Geriatrics, Heart Failure, Heart Valve Diseases, Hypertension, Pulmonary, Mitral Valve Insufficiency, Natriuretic Peptide, Brain, Outcome Assessment, Health Care, Phenotype, Stroke Volume, Survival, Transcatheter Aortic Valve Replacement, Walk Test


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