Incidence and Standardized Definitions of Mitral Valve Leaflet Adverse Events After Transcatheter Mitral Valve Repair: the EXPAND Study
FM Asch, SH Little, GB Mackensen et al.

KEYWORDS
mitral valve leaflet adverse events; LAE; definition; MitraClip;

BACKGROUND - An independent panel of experts reviewed all investigator-reported cases of mitral valve leaflet adverse events (LAE) after MitraClip^TM NTR/XTR in the EXPAND Study.

AIMS - We aimed to report the findings of the expert panel and standardize definitions for LAE.   

METHODS - Standard definitions for different types of LAE were formulated and events adjudicated after detailed review by the expert panel.

RESULTS - Enrolling centers reported LAE in 35 cases, 11 leaflet injuries (9 tear, 2 perforation) and 24 single leaflet device attachment (SLDA). The panel confirmed LAE in 20 cases (2.0% incidence), 18 patients had SLDA and 4 had leaflet injury (2 cases had both SLDA and injury). Leaflet injury occurred during device implant and resulted in surgical valve replacement or death. SLDA-alone events were identified during implant (n=2), pre-discharge (7) or at 30 days of follow-up (7) and were resolved (£ 2+ residual MR) with additional clips in 75% of cases.

CONCLUSIONS - Mitral valve repair with MitraClip^TM NTR/XTR is safe. The rate of LAE is lower than previously reported using older generation devices. The proposed definitions and findings will help differentiate leaflet injury from inadequate leaflet insertion and SLDA, and provide guidance to consistently diagnose LAE post MitraClip^TM.