Transcatheter edge-to-edge repair vs medical therapy in atrial functional mitral regurgitation: a propensity score-based comparison from the OCEAN-Mitral and REVEAL-AFMR registries.

BACKGROUND AND AIMS Atrial functional mitral regurgitation (AFMR) commonly affects elderly and frail individuals. The prognostic impact of transcatheter edge-to-edge repair (TEER) for AFMR has not been investigated. METHODS Patients with AFMR who underwent TEER were selected from the OCEANMitral registry, and medically managed controls were selected from the REVEALAFMR registry, using an identical AFMR definition. The primary endpoint was a composite of all-cause mortality and heart failure hospitalization. The secondary endpoint was all-cause mortality. RESULTS A total of 1,081 patients (mean age 80.1±8.2 years, 60.5% female) with moderate or severe AFMR were included, of whom 441 underwent TEER and 640 remained on medical treatment. Overlap weighting based on propensity score yielded well-balanced characteristics (n=441 vs. 640; all standardized mean differences <0.01), where TEER was associated with a lower incidence of the primary (hazard ratio [HR] 0.65 [0.43-0.99], p=0.044) and secondary endpoints (HR 0.58 [0.35-0.99], p=0.044). In an exploratory subgroup analysis, favorable outcomes might be pronounced in patients with ≤mild residual AFMR after TEER, while event rates in those with ≥moderate residual AFMR were comparable to the medication group. As sensitivity analyses, inverse probability of treatment weighting (n=158 vs. 173), propensity score matching (n=104 vs. 104), and multivariable Cox regression (n=441 vs. 640) all confirmed favorable associations of TEER with both endpoints. CONCLUSIONS In real-world data, TEER for patients with moderate or severe AFMR was associated with a lower incidence of adverse events compared with medical treatment.