Background

Mitral valve-in-valve (MViV) is a safe and effective therapy for severe bioprosthetic mitral degeneration associated with high one-year survival rates. Longer-term survival and reintervention rates are not well defined.

Methods

Retrospective analysis of patients undergoing transseptal MViV with SAPIEN 3 valve family for failed surgical bioprostheses from June 2015 to March 2024 in the Transcatheter Valve Therapy Registry with Centers for Medicare and Medicaid Services data linkage was performed. The primary outcomes were all-cause mortality, stroke, and reintervention. Kaplan Meier and Cox proportional hazards analysis of outcomes was performed according to Society of Thoracic Surgeons (STS) score and procedure status.

Results

5,971 patients (72.9 ± 11.4 years, 57.9% female) underwent MViV. Low (<4), intermediate (4-8), and high (>8) STS scores were present in 1310 (23.5%), 1960 (35.1%) and 2315 (41.5%) patients, respectively. 30-day mortality occurred in 0.9% of patients with low STS scores; 2.7%, intermediate; and 7.0%, high (p<0.001). Predicted mortality at 3 years was proportional to STS score at 15.8%, 23.3%, and 44.5% (p<0.001 for all comparisons). Stroke rates at 3 years were comparable except between low and high STS groups (7.6% vs. 11.4%, p=0.002). Mitral valve reintervention during 3 years of follow-up was similarly uncommon in all groups at 3.8, 3.0, and 2.8% (p=0.71), respectively. Elective procedures were associated with lower 3-year mortality compared to non-elective procedures (HR 0.51, [95% CI: 0.45, 0.58], p<0.001). Strongest predictors of 3-year mortality included current hemodialysis, cardiogenic shock on presentation, and immunocompromised state.

Conclusion

Three-year survival after MViV is favorable in low and intermediate STS scores and elective procedures, whereas survival was significantly lower in high STS scores and non-elective procedures. These findings emphasize the importance of early identification and treatment of patients who may benefit from MViV. Reintervention rates at 3 years are low regardless of STS score.

Clinical Perspectives

What is new?

Three-year survival after transseptal mitral valve-in-valve (MViV) is favorable in patients with low and intermediate Society of Thoracic Surgeons (STS) risk scores High STS risk score and non-elective procedure status are associated with higher 3-year mortality Reintervention rates after MViV are low at 3 years regardless of STS score

What are the clinical implications?

MViV is an effective therapy associated with favorable mid-term outcomes in carefully selected patients Strategies to treat patients before advanced comorbidities develop are needed to optimize longer-term outcomes following MViV