Estimated treatment effects of mitral transcatheter edge-to-edge repair (M-TEER) in COAPT trial participants and real-world patients from the STS/ACC TVT Registry were similar, according to a recent study published in JACC.

In their transportability analysis, Christina Lalani, MD; Robet W. Yeh, MD, FACC; et al., included 614 COAPT trial participants and 15,275 registry patients – 7,289 of the registry patients were COAPT trial eligible. Treatment effects of COAPT trial interventions, including M-TEER and optimization of medical therapy, were estimated for two target populations: trial-eligible patients and treatment-candidate patients with secondary mitral regurgitation (MR) regardless of trial eligibility. The study's primary outcome was heart failure (HF) hospitalization at two years. A key secondary outcome was all-cause death.

Among patients who were trial eligible, M-TEER plus other COAPT trial interventions would see a two-year absolute risk reduction of 17% for HF hospitalizations (95% CI, –28.7% to –5.7%) and 15.4% for all-cause death (95% CI, –26.6% to –5.2%) compared with medical therapy alone. This treatment effect was similar to estimates from the trial (p>0.05). The estimated treatment effect was also similar among patients in the broader treatment-candidate population (p=0.90).

Lalani and colleagues note that trial-eligible patients from the registry were more likely to have ischemic cardiomyopathy and 4+ MR compared with COAPT trial participants. "Although there are notable differences in characteristics between COAPT trial patients and patients undergoing M-TEER for secondary [MR] in routine clinical practice, our results suggest that the safety and efficacy of the trial interventions...are likely similar in the two populations, to the extent that certain assumptions...hold," they write.

In an accompanying editorial comment, Sreekanth Vemulapalli, MD, and Andrew Wang, MD, FACC, add that "this novel effectiveness evaluation of M-TEER reassures us that if clinicians can reproduce the close follow-up and careful optimization of medical therapy achieved in the COAPT trial, we should expect similar reductions in mortality and HF hospitalizations in the real world, even when patient selection extends beyond the trial population."