Relationship between Mitral Regurgitation and Transcatheter Aortic Valve Implantation: a Multi-Institutional Follow-up Study

Background: Mitral regurgitation (MR) is prevalent in patients undergoing transcatheter aortic valve implantation (TAVI). There are some controversies about the prognostic impact of MR in survival of TAVI patients. Objective: To examine the relationship between TAVI and MR in a patient population from the Brazilian TAVI Registry. Methods: Seven hundred and ninety-five patients from the Brazilian TAVI Registry were divided at baseline, discharge, and follow-up according to their MR grade as follows: absent/mild (AMMR) or moderate/severe (MSMR). They were subsequently regrouped according to their immediate and late changes in MR severity after TAVI as follows: no change, improved, or worsened MR. Predictors and prognostic impact on baseline as well as changes in MR severity were analyzed. Statistical significance was set at p < 0.05. Results: Baseline MSMR was present in 19.3% of patients and was a predictor of increased late mortality. Immediately after TAVI, 47.4 % of cases improved to AMMR, predicted by a higher Society of Thoracic Surgeons score and a higher grade of baseline aortic regurgitation. Upon follow-up, 9.2% of cases of AMMR worsened to MSMR, whereas 36.8% of cases of MSMR improved to AMMR. Lower baseline left ventricular ejection fraction (LVEF) and improvement in LVEF at follow-up were predictors of MR improvement. Progressive worsening of MR upon follow-up was an independent predictor of higher late mortality after TAVI (p = 0.005). Conclusions: Baseline MSMR predicts late mortality after TAVI. Lower LVEF and improved LVEF at follow-up predict MR improvement after TAVI. Progressive worsening of MR severity at follow-up is an independent predictor of late mortality, which is a rare finding in the literature.