Short- and mid-term outcomes in percutaneous mitral valve replacement using balloon expandable valves

Background: Due to elevated surgical risk, transcatheter mitral valve replacement (TMVR) is used as an alternative for treating failed bioprosthetic valves, annuloplasty repairs and mitral annular calcification (MAC). We report the procedural and longitudinal outcomes for each subtype: Mitral valve-in-valve (MVIV), mitral valve-in-ring (MViR), and valve-in-MAC (ViMAC). Methods: Consecutive patients undergoing TMVR from October 2013 to December 2019 were assessed. Patients at high risk for left ventricular outflow tract obstruction had either alcohol septal ablation or intentional laceration of the anterior leaflet (LAMPOON). Results: Eight-eight patients underwent TMVR; 38 MViV, 31 MViR, and 19 ViMAC procedures were performed. The median Society of Thoracic Surgery 30-day predicted risk of mortality was 8.2% (IQR 5.2, 19.9) for all. Sapien 3 (78%) and transseptal access (98%) were utilized in most cases. All-cause in-hospital mortality, technical, and procedural success were 8%, 83%, and 66% respectively. Median follow up was 1.4 years (IQR 0.5–2.9 years) and overall survival was 40% at 4 years. Differential survival rates were observed with MViV doing the best, followed by MViR and ViMAC having a <20% survival at 4 years. After adjusting for co-variates, MViV procedure was the strongest predictor of survival (HR 0.24 [95% CI 0.079–0.7]). Conclusion: TMVR is performed in at high-risk patients with attenuated long-term survival. MViV has the best success and survival rate, but long-term survival in MViR and ViMAC is guarded.