Newer-generation (G4) mitral transcatheter edge-to-edge repair (M-TEER) systems, compared to early (G2) systems, offered a safer and more efficient procedure, with shorter procedural time, fewer mechanical complications, fewer clips and a lower postprocedural transmitral mean pressure gradient (TMPG), according to results from a study published July 15 in JACC: Asia. These outcomes contributed to reduced heart failure (HF) rehospitalization risk, particularly in degenerative mitral regurgitation (DMR).

Using data from the ongoing investigator-initiated OCEAN Mitral registry, Taishi Okuno, MD, et al., compared procedural and clinical outcomes with the G2 and G4 MitraClip TEER systems in 3,738 patients with DMR or functional mitral regurgitation (FMR) who underwent M-TEER at 21 centers in Japan. Of these, 1,481 patients were treated with the G2 system and 2,257 with the G4 system. Follow-up assessments occurred at one month, one year and annually thereafter.

Results showed procedural success was similar in the G4 and G2 groups (residual MR ≤2+), although the G4 patients were older (81 vs. 80 years) and had higher surgical risk scores (median EuroSCORE II 5.14 vs. 4.86).

In the G4 group, compared to G2, the shorter procedure time and fewer clips used led to a significantly lower TPMG: median 2.7 mm Hg vs. 3.0 mm Hg in the DMR cohort and 2.5 mm Hg vs. 3.0 mm Hg in the FMR cohort. While rare overall in both groups, mechanical complications such as single leaflet device attachment and leaflet tear, were further reduced in the G4 group.

Furthermore, HF rehospitalization was lower in the G4 than the G2 group (adjusted hazard ratio, 0.51 in the DMR cohort and 0.76 in the FMR cohort). The postprocedural TPMG modestly mediated the association between this risk and the device generation, based on a causal mediation analysis.

"With the widespread adoption of M-TEER, iterative device improvements have culminated in the latest generation's multiple clip size options and independent grasping mechanism," write the authors. "These advancements allow for tailored adaptation to the diverse anatomical variations of the mitral valve, enabling operators to select the optimal clip size and independently control leaflet grasping in complex cases, thereby achieving more reliable and effective [mitral regurgitation] reduction."