Early- Versus Newer-Generation Transcatheter Mitral Valve Edge-to-Edge Repair Systems: Insights From the OCEAN-Mitral Registry.

Abstract

Background: Comparative data on early- (G2) vs newer-generation (G4) MitraClip transcatheter edge-to-edge repair (TEER) systems remain limited.

Objectives: The authors compared procedural and clinical outcomes of both devices in patients with degenerative mitral regurgitation (DMR) or functional mitral regurgitation (FMR).

Methods: Using the OCEAN (Optimized Catheter Valvular Intervention)-Mitral registry, 3,738 patients undergoing TEER with either G2 (n = 1,481) or G4 (n = 2,257) MitraClips were analyzed. Outcomes included procedural metrics, echocardiographic parameters, and clinical events.

Results: Despite being older (P = 0.010) and higher-risk (EuroSCORE [European System for Cardiac Operative Risk Evaluation] II: P = 0.002), the newer-generation group achieved comparable procedural success (residual MR ≤2+) with shorter procedure time and fewer clips, resulting in significantly lower transmitral mean pressure gradients (TMPG) (DMR: median: 3.0 [Q1-Q3: 2.0-4.0] mm Hg vs 2.7 [Q1-Q3: 2.0-3.8] mm Hg; P = 0.009; FMR: median 3.0 [Q1-Q3: 2.0-4.0] mm Hg vs 2.5 [Q1-Q3: 1.9-3.5] mm Hg; P < 0.001) in both DMR and FMR cohorts. Rates of mechanical complications, such as single leaflet device attachment and leaflet tear, were rare across both device generations but were further reduced in the newer-generation device. The newer-generation device was associated with reduced heart failure (HF) rehospitalization in DMR (adjusted HR: 0.51; 95% CI: 0.33-0.77; P = 0.001) and FMR (adjusted HR: 0.76; 95% CI: 0.61-0.93; P = 0.009), with a greater risk reduction in DMR (P_interaction < 0.001). A causal mediation analysis revealed that postprocedural TMPG modestly mediated the association between device generation and HF rehospitalization risk (proportion mediated = 1.8% [Q1-Q3: 0.3%-4.0%]; P = 0.016).

Conclusions: The newer-generation TEER system offers a safer and more efficient procedure, with shorter procedural time, fewer mechanical complications, fewer clips, and a lower postprocedural TMPG, contributing to reduced HF rehospitalization risk, particularly in DMR.