Contemporary Outcomes Following Transcatheter Edge-to-Edge Repair: 1-Year Results From the EXPAND Study

Background: The third-generation MitraClip NTR/XTR transcatheter edge-to-edge repair system was introduced to assist in leaflet grasping with the longer clip arms of MitraClip XTR and to improve ease of use with the modified delivery catheter. Objectives: The EXPAND study evaluated contemporary real-world outcomes in subjects with mitral regurgitation (MR) treated with the third-generation MitraClip NTR/XTR transcatheter edge-to-edge repair system. Methods: EXPAND is a prospective, multicenter, international, single-arm study that enrolled patients with primary MR and secondary MR at 57 centers. Follow-up was conducted through 12 months. Echocardiograms were analyzed by an echocardiographic core laboratories. Study outcomes included: MR severity, functional capacity measured by New York Heart Association functional class, quality of life measured by Kansas City Cardiomyopathy Questionnaire, heart failure hospitalizations, all-cause mortality. Results: 1,041 patients were enrolled from April 2018 through March 2019, of which 50.5% had primary or mixed etiology. Implant success was 98.9%; 1.5 ± 0.6 clips were implanted per subject. Significant MR reduction from baseline (≥MR 3+: 56.0%) to 30 days (≤MR 1+:88.8%) was maintained through 1 year (MR ≤1+: 89.2%). A total of 84.5% and 93.0% of subjects in primary MR and secondary MR, respectively, had ≤1+ MR at 1 year. Significant improvements were observed in clinical outcomes (New York Heart Association functional class I/II in 80.3%, +21.6 improvement in Kansas City Cardiomyopathy Questionnaire score) at 1 year. All-cause mortality and heart failure hospitalizations at 1 year were 14.9% and 18.9%, respectively, which was significantly lower than previous studies. Conclusions: The study demonstrates treatment with the third-generation system resulted in substantial reduction of MR in a contemporary real-world practice, compared with the results of earlier EVEREST and COAPT trials.(The MitraClip® EXPAND Study of the Next Generation of MitraClip® Devices [EXPAND]; NCT03502811)