A Score to Assess Mortality After Percutaneous Mitral Valve Repair

BACKGROUND Risk stratification for transcatheter edge-to-edge mitral valve repair (TEER) is paramount in the decision-making process for treating severe mitral regurgitation (MR). OBJECTIVES This study sought to create and validate a user-friendly score (MitraScore) to predict the risk of mortality in patients undergoing TEER. METHODS The derivation cohort was based on a multicentric international registry that included 1,119 patients referred for TEER between 2012 and 2020. Score discrimination was assessed using Harrell's c-statistic, and the calibration was evaluated with the Gronnesby and Borgan goodness-of -fit test. An external validation was carried out in 725 patients from the GIOTTO registry. RESULTS After multivariate analysis, we identified 8 independent predictors of mortality during the follow-up (2.1 +/- 1.8 years): age $75 years, anemia, glomerular filtrate rate <60 mL/min/1.73 m2, left ventricular ejection fraction <40%, peripheral artery disease, chronic obstructive pulmonary disease, high diuretic dose, and no therapy with reninangiotensin system inhibitors. The MitraScore was derived by assigning 1 point to each independent predictor. The c-statistic was 0.70. Per each point of the MitraScore, the relative risk of mortality increased by 55% (HR: 1.55; 95% CI: 1.44-1.67; P < 0.001). The discrimination and calibration for mortality prediction was better than those of EuroSCORE II (c-statistic 0.61) or Society of Thoracic Surgeons score (c-statistic 0.57). The MitraScore maintained adequate performance in the validation cohort (c-statistic 0.66). The score was also predictive for heart failure rehospitalization and was correlated with the probability of clinical improvement. CONCLUSIONS The MitraScore is a simple prediction algorithm for the prediction of follow-up mortality in patients treated with TEER. (c) 2022 by the American College of Cardiology Foundation.

Automated summary

This study aimed to create and validate a user-friendly score (MitraScore) to predict the risk of mortality in patients undergoing transcatheter edge-to-edge mitral valve repair (TEER). The MitraScore, derived from 8 independent predictors, showed better discrimination and calibration in predicting mortality compared to existing scores. It also demonstrated predictive value for heart failure rehospitalization and correlated with the probability of clinical improvement.