Outcomes of Mitral Transcatheter Edge-to-Edge Repair in Patients With Small Mitral Valve Area

A small baseline mitral valve area (MVA) raises concern for iatrogenic mitral stenosis due to increased transmitral pressure gradients (TMPG) after mitral transcatheter edge-to-edge repair (M-TEER). Outcomes in patients with MVA <4.0 cm² remain limited, as this population has been largely excluded from clinical trials.

We retrospectively analyzed 305 consecutive patients who underwent M-TEER (2014-2022). Patients were stratified by baseline MVA (<4.0 cm² vs. ≥4.0 cm²). The primary endpoint was 2-year all-cause mortality. Secondary endpoints included heart failure hospitalization (HFH), mitral regurgitation (MR) reduction, New York Heart Association functional class improvement, and postprocedural TMPG.

Of 305 patients, 66 (21.6%) had MVA <4.0 cm². Women were more prevalent in the small MVA group (57.6% vs. 42.7%; p = 0.03). Patients with smaller MVA received fewer clips (1.3 ± 0.07 vs. 1.5 ± 0.04; p = 0.03). Procedural success and in-hospital outcomes were comparable. At discharge, residual MR (p = 0.006). At 30 days and 1 year, mortality, HFH, and residual MR rates remained similar. Two-year Kaplan-Meier analyses showed no differences in survival, HFH, or composite outcomes. In multivariable analysis, age, creatinine, and hemoglobin predicted mortality, while age, LVEF, and hemoglobin predicted the composite outcome. Indexed MVA did not predict mortality or elevated TMPG.

M-TEER can be safely and effectively performed in patients with baseline MVA <4.0 cm² without adverse clinical outcomes through 2 years.