The fourth-generation mitral transcatheter edge-to-edge repair (M-TEER) device introduced an improved clip deployment sequence, independent leaflet grasping, and 2 wider clip sizes to tailor the treatment of patients with mitral regurgitation (MR) for a broad range of anatomies. The 30-day safety and effectiveness of the fourth-generation M-TEER device were previously demonstrated. The aim of this study was to evaluate 1-year outcomes in a contemporary, real-world cohort of subjects treated with the MitraClip G4 system. EXPAND G4 is an ongoing prospective, multicenter, international, single-arm study that enrolled subjects with primary and secondary MR. One-year outcomes included MR severity (echocardiographic core laboratory assessed), heart failure hospitalization, all-cause mortality, functional capacity (NYHA functional class), and quality of life (Kansas City Cardiomyopathy Questionnaire). A total of 1,164 subjects underwent M-TEER from 2020 to 2022. At 1 year, there was a durable reduction in MR to mild or less in 92.6% and to none or trace in 44.2% (P < 0.0001 vs baseline). Few subjects had major adverse events through 1 year (<2% for myocardial infarction, surgical reintervention, or single-leaflet device attachment). The 1-year Kaplan-Meier estimates for all-cause mortality and heart failure hospitalization were 12.3% and 16.9%. Significant improvements in functional capacity (NYHA functional class I or II in 82%; P < 0.0001 vs baseline) and quality of life (18.5-point Kansas City Cardiomyopathy Questionnaire overall summary score improvement; P < 0.0001) were observed. M-TEER with the fourth-generation M-TEER device was safe and effective at 1 year, with durable reductions in MR severity to ≤1+ in more than 90% of patients and concomitant improvements in functional status and quality of life.

Anatomical and clinical criteria to define mitral transcatheter edge-to-edge repair (TEER) "unsuitability" have been proposed on the basis of a Heart Valve Collaboratory consensus opinion from physician experience with early-generation TEER devices but lacked an evidence-based approach. The aim of this study was to explore the spectrum of TEER suitability using echocardiographic and clinical outcomes from the EXPAND G4 real-world postapproval study. EXPAND G4 is a global, prospective, multicenter, single-arm study that enrolled 1,164 subjects with mitral regurgitation (MR) treated with the MitraClip G4 System. Three groups were defined using the Heart Valve Collaboratory TEER unsuitability criteria: 1) risk of stenosis (RoS); 2) risk of inadequate MR reduction (RoIR); and 3) subjects with baseline moderate or less MR (MMR). A TEER-suitable (TS) group was defined by the absence of these characteristics. Endpoints included independent core laboratory-assessed echocardiographic characteristics, procedural outcomes, MR reduction, NYHA functional class, Kansas City Cardiomyopathy Questionnaire score, and major adverse events through 30 days. Subjects in the RoS (n = 56), RoIR (n = 54), MMR (n = 326), and TS (n = 303) groups had high 30-day MR reduction rates (≤1+: RoS 97%, MMR 93%, and TS 91%; ≤2+: RoIR 94%). Thirty-day improvements in functional capacity (NYHA functional class I or II at 30 days vs baseline: RoS 94% vs 29%, RoIR 88% vs 30%, MMR 79% vs 26%, and TS 83% vs 33%) and quality of life (change in Kansas City Cardiomyopathy Questionnaire score: RoS +27 ± 26, RoIR +16 ± 26, MMR +19 ± 26, and TS +19 ± 24) were safely achieved in all groups, with low major adverse events (<3%) and all-cause mortality (RoS 1.8%, RoIR 0%, MMR 1.5%, and TS 1.3%). Patients previously deemed TEER unsuitable can be safely and effectively treated with the mitral TEER fourth-generation device.