Ventricular Remodeling and Outcomes After Mitral Transcatheter Edge-to-Edge Repair in Heart Failure: The COAPT Trial

Background: The relationship between left ventricular (LV) remodeling and clinical outcomes after treatment of severe mitral regurgitation (MR) in heart failure (HF) has not been examined.

Objectives: The aim of this study was to evaluate the association between LV reverse remodeling and subsequent outcomes and assess whether transcatheter edge-to-edge repair (TEER) and residual MR are associated with LV remodeling in the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation) trial.

Methods: Patients with HF and severe MR who remained symptomatic on guideline-directed medical therapy (GDMT) were randomized to TEER plus GDMT or GDMT alone. Baseline and 6-month core laboratory measurements of LV end-diastolic volume index and LV end-systolic volume index were examined. Change in LV volumes from baseline to 6 months and clinical outcomes from 6 months to 2 years were evaluated using multivariable regression.

Results: The analytical cohort comprised 348 patients (190 treated with TEER, 158 treated with GDMT alone). A decrease in LV end-diastolic volume index at 6 months was associated with reduced cardiovascular death between 6 months and 2 years (adjusted HR: 0.90 per 10 mL/m² decrease; 95% CI: 0.81-1.00; P = 0.04), with consistent results in both treatment groups (P_interaction = 0.26). Directionally similar but nonsignificant relationships were present for all-cause death and HF hospitalization and between reduced LV end-systolic volume index and all outcomes. Neither treatment group nor MR severity at 30 days was associated with LV remodeling at 6 or 12 months. The treatment benefits of TEER were not significant regardless of the degree of LV remodeling at 6 months.

Conclusions: In patients with HF and severe MR, LV reverse remodeling at 6 months was associated with subsequently improved 2-year outcomes but was not affected by TEER or the extent of residual MR. (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation [The COAPT Trial] and COAPT CAS [COAPT]; NCT01626079).