Introduction
Two randomised controlled studies (MITRA-FR, COAPT) evaluated the role of transcatheter mitral valve repair (TMVr) in the treatment of functional mitral regurgitation (FMR). Although both s studies’ methodologies were similar,, they yielded conflicting results. We hypothesized that the differences in the inclusion and exclusion criteria of thetrials may have influenced outcomes.
Materials and Methods
We analyzed FMR patients from Padeh medical center prospective TMVr registry. Univariable and multivariable cox regression analyses were applied on demographic, medical background, clinical and echocardiographic parameters. Both COAPT and MITRA-FR inclusion and exclusion criteria echocardiographic parameters were entered into the model. We tested for the composite endpoint of time to mortality and/or first heart failure hospitalization. The Mitraclip© system was used in all procedures.
Results and discussion
Overall, 90 patients have undergone TMVr between October 2015 and February 2021, of which 58 patients with FMR were included in the analysis. Their mean age was 75±6.81 years, and 25 (43%) were female. 46 (79%) had concomitant coronary artery disease (CAD). 9 procedures (15%) were urgent.
Univariable analysis indicated that the COAPT inclusion criteria of left ventricular ejection fraction (LVEF) of between 50% and 20% was significantly associated with the endpoint (HR 4.685 95% CI 1.308-16.784 p=0.018). Multivariable analysis indicated that none of COAPT or MITRA-FR echocardiographic criteria were predictive of the endpoint. NYHA class showed a strong association with the endpoint (HR 2.674, 95% CI 1.124-6.358; p=0.026), whereas diabetes mellitus and past myocardial infarction showed strong trend (p<0.057 and 0.054 respectively).
Conclusions
According to this analysis, the conflicting results of COAPT and MITRA-FR may not be related to the differences in inclusion or exclusion echocardiographic parameters of the trials. The echocardiographic criteria which carry favorable results with TMVr of FMR remains elusive. Our results would need further validation in larger scale trials.