Five-year outcomes of transcatheter mitral valve implantation and redo surgery for mitral prosthesis degeneration

Background: Transcatheter mitral valve replacement (TMVR) has emerged as a feasible alternative to redo surgical mitral valve replacement (SMVR) in patients with degenerated mitral prostheses, with limited comparative data. Methods: We compared mid-term outcomes in patients with degenerated mitral valve prostheses treated with TMVR or redo SMVR. The primary endpoint was survival at 5 years of follow-up. Results: From 2014 to 2020, 215 patients presented with degenerated mitral valve prostheses. Of whom 86 (40%) were treated with TMVR (75[87%] valve-in-valve and 11[13%] valve-in-ring), while 129 patients (60%) underwent SMVR. The TMVR cohort was older (p < 0.0001), more symptomatic (p = 0.0003) and had more chronic lung disease (p = 0.02), worse renal function (p = 0.02) and higher right ventricular systolic pressures (p < 0.0001). Thirty-day mortality was lower with TMVR versus SMVR (2.4% vs. 10.2%, OR4.69 [95% CI 1.25–30.5], p = 0.04) with probability of mortality at 1, 2, and 5 years being 14.7% versus 17.5%, 24.5% versus 20.7%, and 49.9% versus 34.0%, respectively. Mode of prosthesis degeneration, baseline hemodynamics, and valve selection did not appreciably impact outcomes. Conclusions: TMVR for degenerated mitral prostheses is associated with better early survival compared to SMVR despite a greater burden of comorbidities. In contrast, 5 year survival rates appear more favorable with SMVR, which may reflect the lower baseline risk of this population. Clinical, hemodynamic, and echocardiographic follow-up support the mid-term durability of TMVR for degenerated mitral prostheses. Further dedicated studies, however, are required to optimize outcomes in this challenging patient cohort and to navigate the choice of approach for each individual patient.