Clinical Outcomes With Transcatheter Edge-to-Edge Repair in Atrial Functional MR From the EXPAND Study

Although transcatheter edge-to-edge repair (TEER) has been shown to improve clinical outcomes and improve quality of life in patients with symptomatic secondary mitral regurgitation (SMR) and left ventricular dysfunction, its effect in patients with atrial SMR (aSMR) has not been well described.

The aim of this study was to assess the safety, echocardiographic outcomes, and clinical effectiveness of TEER for aSMR.

Patients with aSMR in the prospective, observational, multicenter EXPAND (A Contemporary, Prospective, Multi-Center Study Evaluating Real-World Experience of Performance and Safety for the Next Generation of MitraClip Devices) study were identified by an echocardiography core laboratory. Follow-up occurred at discharge, 30 days, and 1 year. Key endpoints included mitral regurgitation (MR) severity, functional class, heart failure hospitalizations, mortality, and 30-day major adverse events.

Among 1,041 patients enrolled in EXPAND, 835 patients had evaluable echocardiograms at baseline. Of these, 53 patients had aSMR and 360 had ventricular SMR (vSMR). In the aSMR cohort, TEER resulted in a significant reduction in MR through 1 year (MR grade ≤2 in 100.0%), significantly increased 1-year Kansas City Cardiomyopathy Questionnaire score (+26.6 ± 30.5 points; P < 0.0001), and improved functional class from baseline, similar to the effects among patients with vSMR (MR grade ≤2 in 99.5% at 1 year, 1-year increase in Kansas City Cardiomyopathy Questionnaire score 21.23 ± 24.92 points). Major adverse events at 30 days and leaflet adverse events at 1 year were infrequent in both groups.

In a prospective, real-world, global registry, TEER for aSMR was associated with significant MR reduction and improvement in quality of life and functional class, similar to patients with vSMR. This suggests that TEER may provide clinical benefit in patients with atrial fibrillation with SMR in the setting of heart failure with preserved ejection fraction. (The MitraClip® EXPAND Study of the Next Generation of MitraClip® Devices; NCT03502811).