Mitral Reoperation After Transcatheter Mitral Valve Replacement: The Society of Thoracic Surgeons Adult Cardiac Surgery Database Analysis

S. Fukuhara¹, G. Ailawadi², M. Romano³, S. F.. Bolling⁴, R. Hawkins^1
1University of Michigan, Ann Arbor, Michigan ²The University of Michigan Cardiovascular Center, Ann Arbor, Michigan ³University of Michigan Medical Center, Ann Arbor, Michigan ⁴University of Michigan Hospital, Ann Arbor, Michigan

Purpose: Despite the global interest in transcatheter mitral valve replacement (TMVR), its growth lags behind transcatheter aortic valve replacement (TAVR). In this context, mitral reoperation after TMVR remains poorly characterized. We aimed to delineate the features of post-TMVR reoperations using the Society of Thoracic Surgeons (STS) database.

Methods: We queried the STS Adult Cardiac Surgery database for mitral valve reoperations after TMVR from 2013 to 2022, identifying 318 patients for analysis. Patients undergoing non-mitral procedures (n=203) were excluded. Patients were stratified by index TMVR procedures including valve-in-valve TMVR within a surgical bioprosthesis (ViV-TMVR, n=186; 58.5%), valve-in-ring TMVR within a surgical prosthetic ring (ViR-TMVR, n=71; 22.3%), and native-TMVR (n=61; 19.2%). Differences in TMVR groups were analyzed by univariable analysis. Linear regression analyzed trends over time. Subanalysis was performed on the 170 (53.5%) patients with STS predicted risk of mortality (STS-PROM) scores available.

Results: The 318 reoperations were performed by 283 surgeons (median 1 case/surgeon [Q1-Q3 1-1]) from 162 centers (median 1 case/center [1-2]). The case volume significantly increased from 1 in 2013 to 75 in 2022 (linear regression +7.5 cases/year (95% confidence interval [CI] 5.9-9.1, p< 0.001, R2=0.94). Conversely, same day conversion cases to open during TMVR were low, only 1.3% (1/75 cases) in 2022 (Figure). Overall, the median age was 67 years [55-74], 56.9% of cases were urgent/emergent, and 4.4% of reoperations involved same-day approach conversion from TMVR. Native-TMVR reoperations were generally higher risk with patients being significantly older, having more prior TAVR procedures, and most commonly emergent status (Table). No differences were observed in cardiopulmonary bypass/aortic-cross clamp times or mechanical circulatory support among groups. Operative mortality was 18.3%, 15.5%, and 27.9%, respectively (p=0.16). Elective procedures, compared with urgent/emergent procedures, demonstrated lower mortality in the ViV-TMVR (9.5 vs 26.0%; p=0.002) and ViR-TMVR groups (8.3 vs 22.9%; p=0.091), whereas not in the native-TMVR group (31.6 vs 26.2%, p=0.66). For the subgroup with available STS-PROM, the median predicted risk of mortality did not differ by group (Table). The overall observed-to-expected mortality ratio was 1.27 (95% CI 0.88-1.79), not significantly different than 1 (p=0.229).

Conclusion: Post-TMVR reoperations remain rare but are increasing. Reoperative TMVR patients are relatively young but high acuity with corresponding high mortality rates, particularly native-TMVR cases. In the absence of clear redo TMVR feasibility or outcome data, transparent counseling regarding possible future reoperation is necessary for this high-risk cohort. These findings may aid in the selection of appropriate index TMVR and post-TMVR reoperation candidates as TMVR practices expand globally.

Identify the source of the funding for this research project: None.