Outcomes of Transcatheter Edge-to-Edge Mitral Valve Repair in Hypertrophic Cardiomyopathy: A Patient-Level Meta-Analysis.

Background: Hypertrophic cardiomyopathy (HCM) is commonly associated with left ventricular outflow tract (LVOT) obstruction and mitral regurgitation (MR). Transcatheter edge-to-edge repair (TEER) of the mitral valve has been introduced as a therapeutic alternative for individuals with LVOT obstruction and concurrent MR, but there are insufficient outcome data. We aim to perform a systematic review and patient-level meta-analysis of the studies reporting the outcomes of TEER of the mitral valve in HCM. Methods: Original studies published in PubMed and Google Scholar were included if ​≥1 of the following pre- and post-TEER measures were reported: peak resting or provoked LVOT gradients, MR grade, mitral valve gradient, or New York Heart Association (NYHA) functional class. One unpublished case from the Minneapolis Veterans Affairs Medical Center was also included. Results: Nineteen publications and 37 patients (mean age 70.1 [±15.2] years, 50% male, mean follow-up time of 9.2 [±6.4] months) were analyzed. Compared to baseline measurements, there was a significant reduction in the mean peak resting and provoked LVOT gradients (69.2 [±40.3] mmHg vs. 11.7 [±8.6] mmHg and 98.2 [±53.4] mmHg vs. 14.1 [±13.9] mmHg, respectively), median MR grade (4.0 [3.0-4.0] vs. 1.0 [1.0-1.0]), and proportion of patients with an NYHA functional class ≥3 (100 vs. 7%) post-TEER (all p < 0.001). There was a significant increase in mean mitral valve gradients post-TEER (2.2 [±1.0] mmHg vs. 4.3 [±1.3] mmHg, p < ​0.001). Conclusions: TEER can be an effective therapeutic option for improving LVOT obstruction, MR severity, and NYHA functional class in patients with HCM.