Outcomes of Transcatheter Edge-to-Edge Repair for Functional Mitral Regurgitation According to Cardiac Resynchronization Therapy Status

Current guidelines, supported by limited data, prioritize the use of cardiac resynchronization therapy (CRT) over mitral transcatheter edge-to-edge repair (TEER) in eligible patients. To examine TEER results and outcomes in CRT-eligible patients with functional mitral regurgitation (MR) according to CRT status, we conducted a single-center, retrospective analysis of 126 consecutive patients who underwent TEER while fulfilling guideline criteria for CRT before the procedure. The primary outcome was the composite of all-cause mortality or heart failure hospitalizations at 1 year. The secondary outcomes included individual components of the primary outcome, as well as 1-year all-cause hospitalizations and 1-month MR severity, indexed left atrial volume, and indexed left ventricular mass by echocardiography. A total of 70 patients (56%) did not undergo CRT at the time of TEER. The baseline characteristics and procedural results were mostly comparable between those with and without CRT. The no-CRT group experienced higher rates of the primary outcome (43% vs 25%, p = 0.041), which were accounted for by increased mortality (26% vs 11%, p = 0.033). After multivariable analysis, the absence of CRT was associated with more than twice the risk for the primary outcome (hazard ratio 2.36, 95% confidence interval 1.1 to 4.98, p = 0.0.017), a finding which was confined to patients with a class I indication for the device. Rates of secondary endpoints did not differ between the groups. In conclusion, in CRT-eligible patients who underwent TEER for functional MR, the 1-year clinical outcome was more favorable when the procedure was preceded by CRT.