One-year real-world outcomes for patients undergoing transcatheter mitral valve repair: the Gulf MTEER registry (GULF Mitral Transcatheter Edge to Edge Repair)

BACKGROUND: Severe mitral regurgitation (MR) with left ventricular dysfunction portends worse outcomes. Over the course of the last two decades, transcatheter repair of the mitral valve offered an alternative therapeutic modality for those deemed inoperable or high risk. Landmark studies such as the Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation and Multicentre Study of Percutaneous Mitral Valve Repair MitraClip Device in Patients With Severe Secondary Mitral Regurgitation trials have shown conflicting results with respect to all-cause death and heart failure rehospitalisations. The Gulf Mitral Transcatheter Edge to Edge Repair registry (Gulf MTEER registry) is a regional registry that captured outcomes in those undergoing transcatheter repair of the mitral valve. The objectives of this study were to describe the baseline characteristics of patients undergoing transcatheter mitral valve repair in the Gulf region and estimate the cardiovascular effects of the mitral transcatheter therapies in routine practice. METHODS: The Gulf MTEER registry is an observational, multicentre, retrospective registry that enrolled all patients undergoing transcatheter repair of the mitral valve from four of the Gulf countries (Saudi Arabia, Kuwait, Bahrain, Oman) between 1 January 2017 and 31 December 2019. Baseline characteristics, echocardiographic parameters and immediate procedural success were reported. The primary outcome was a composite of death and rehospitalisations at 1 year. The secondary outcomes were the individual components of the composite endpoint; that is, death and rehospitalisations at 1 year as well as residual or recurrent MR or worsening New York Heart Association class and a need for repeat repair. RESULTS: A total of 176 patients were enrolled. Men constituted 56.3% of the total. At 1 year the primary outcome occurred in 21.1% (95% CI 15.6, 27.9). The secondary outcomes of death occurred in 5.4% (CI 2.9, 10.0) and rehospitalisations occurred in 16.9% (CI 11.9, 23.3). Univariate analysis revealed that the odds of having death or re-hospitalisation was two times higher if the effective regurgitant orifice (ERO) >40 mm² irrespective of the therapy. CONCLUSIONS: The Gulf MTEER registry is the first registry in the Gulf region defining the patient population receiving MTEER therapies and evaluating 1-year outcomes. This is a low risk cohort with a high rate of immediate procedural success and low rate of all-cause death and rehospitalisations at 1 year. The odds of an event was two times higher if the ERO ≥40 mm² with only a signal to higher odds for low left ventricular ejection fraction and larger end systolic dimension.