BACKGROUND Adequacy of echocardiographic findings and clinical outcome after transcatheter mitral valve-in-valvereplacement for degenerative bioprosthesis is not fully understood. METHODS We retrospectively identified patients who underwent mitral valve replacement via either surgical or transcatheter for degenerative mitralbioprosthesis at three US institution. We compared echocardiographic findings and clinical outcome of patientswho had mitral valve-in-valve with those of patients who underwent second surgical mitral valve replacement. RESULTS 58 patients underwent transcatheter mitral valve replacement (TMVR) and 57 patients underwent surgicalmitral valve replacement (SMVR). Mean age and the Society of Thoracic Surgeons- Predicted Risk of Mortality (STS-PROM) were significantly higher in patients with TMVR than in those with SMVR (Age 74.8±11.1years vs 65.9±14.2years, P=0.002; STS-PROM 13.6±8.2% vs 8.9±9.8%, P\u3c0.0001, respectively). Although mean transmitral pressure gradient (MPG) tended to be higher in the TMVR group (6.5±2.8 vs 5.3±2.5, P=0.03), mitral valve area (MVA) and mitralregurgitation grade at discharge were similar between the TMVR group and SMVR group (MVA 2.6±0.8 vs 3.0±1.2, P=0.47; MR (≥mild) 9.6% vs 10.3%, P=0.92, respectively), achieving similar 1-year survival rate (TMVR 83.5% vs SMVR 76.9%, P=0.23). (Figure presented) CONCLUSION Echocardiographic findings after TMVR for degenerative mitral bioprosthesis were acceptable when compared withthose after SMVR, achieving similar one-year survival between the TMVR and the SMVR group
