Abstract 4365260: Safety and Prognostic Implications of Mechanical Circulatory Support-Assisted Transcatheter Edge-to-Edge Repair: Insights from the OCEAN-Mitral Registry

Background: Transcatheter edge-to-edge repair of the mitral valve (M-TEER) has demonstrated promising outcomes for patients with mitral regurgitation (MR) who are unsuitable for surgical intervention. However, the clinical implications of M-TEER in patients requiring mechanical circulatory support (MCS) for unstable hemodynamics remains unclear. Aims: This study aimed to evaluate the outcomes of MCS-assisted M-TEER in critically ill patients. Methods: Consecutive patients who underwent M-TEER for significant MR were identified from the Japanese multicenter OCEAN-Mitral registry. All-cause mortality was compared between the cohort undergoing MCS-assisted M-TEER and a virtual control group, receiving MCS alone without undergoing M-TEER, estimated using the Seattle Heart Failure Model. Additionally, logistic regression analysis was conducted to identify factors associated with in-hospital mortality following MCS-assisted M-TEER. Results: A total of 3764 patients were included in the analysis (mean age: 81 years; 54.9% male; 70.1% with secondary MR), of whom 105 underwent MCS-assisted M-TEER. Procedure success exceeded 95%, irrespective of MCS use. The one-year mortality in the MCS-assisted M-TEER group was lower than the estimated mortality rate in the virtual control group (43.2% vs. 69.5%). Factors associated with in-hospital mortality included frailty, inflammation, and hypoalbuminemia. In a landmark analysis starting from discharge date, there was no statistically significant difference in cardiovascular death or heart failure hospitalization between the groups with or without the usage of MCS (hazard ratio 1.45, 95% confidence interval 0.93-2.26, p = 0.10). Conclusions: MCS-assisted M-TEER appears to be a viable and effective therapeutic strategy for carefully selected patients with significant MR and unstable hemodynamics.