Association Between Hospital Surgical Aortic Valve Replacement Volume and Transcatheter Aortic Valve Replacement Outcomes.

Importance: The Centers for Medicare & Medicaid Services national coverage determination for transcatheter aortic valve replacement (TAVR) includes volume requirements for surgical aortic valve replacement (SAVR) for hospitals seeking to initiate or continue TAVR programs. Evidence regarding the association between SAVR volume and TAVR outcomes is limited. Objective: To examine the association of hospital SAVR and combined SAVR and TAVR volumes with patient outcomes of TAVR procedures performed within 1 year, 2 years, and for the entire period after initiation of TAVR programs. Design, Setting, and Participants: This observational cohort study included 60 538 TAVR procedures performed in 438 hospitals between October 1, 2011, and December 31, 2015, among Medicare beneficiaries. Main Outcomes and Measures: The associations between SAVR volume, SAVR and TAVR volumes, and risks of death, death or stroke, and readmissions within 30 days were determined using a hierarchical logistic regression model adjusting for patient and hospital characteristics. The association between SAVR and SAVR and TAVR volumes and 1-year and 2-year mortality after TAVR procedures was determined using a multivariable proportional hazard model with a robust variance estimator. The associations for procedures performed within 1 year, 2 years, and for the entire period after initiation of TAVR programs were examined.
Results: Among the 60 538 patients, 29 173 were women and 31 365 were men, with a mean (SD) age of 82.3 (8.0) years. Hospitals with high SAVR volume (mean annual volume, ≥97 per year) were more likely to adopt TAVR early and had a higher growth in TAVR volumes over time (median TAVR volume by hospitals with high SAVR volume and low SAVR volume: year 1, 32 vs 19; year 2, 48 vs 28; year 3, 82 vs 38; year 4, 118 vs 54; P < .001). In adjusted analysis, high hospital SAVR volume alone was not associated with better patient outcomes after TAVR. When hospital TAVR and SAVR volumes were jointly analyzed, patients treated in hospitals with high TAVR volume had lower 30-day mortality after TAVR (high TAVR and low SAVR vs low TAVR and low SAVR: odds ratio, 0.85; 95% CI, 0.72-0.99; high TAVR and high SAVR vs low TAVR and high SAVR: odds ratio, 0.81; 95% CI, 0.69-0.95), the effect of which was more pronounced when hospitals also had high SAVR volume. Patients treated in hospitals with high SAVR volume and high TAVR volume had the lowest 30-day mortality (vs hospitals with low SAVR volume and TAVR volume: odds ratio, 0.77; 95% CI, 0.66-0.89). Conclusions and Relevance: Hospitals with high SAVR volume are most likely to be fast adopters of TAVR. Hospital SAVR volume alone is not associated with better TAVR outcomes. Accumulating high volumes of TAVR is associated with lower mortality after TAVR, particularly when hospitals have high SAVR volumes. Hospitals with high caseloads of both SAVR and TAVR are likely to achieve the best outcomes.