Relationship Between Hospital Surgical Aortic Valve Replacement Volume and Transcatheter Aortic Valve Replacement Outcomes
SA Hirji, E McCarthy, D Kim et al.

KEYWORDS
aortic valve replacement; heart valve prosthesis

OBJECTIVES - The aim of this study was to examine whether hospital surgical aortic valve replacement (SAVR) volume was associated with corresponding transcatheter aortic valve replacement (TAVR) outcomes.

BACKGROUND - Recent studies have demonstrated a volume-outcome relationship for TAVR.

METHODS - In total, 208,400 fee-for-service Medicare beneficiaries were analyzed for all aortic valve replacement procedures from 2012 to 2015. Claims for patients <65 years of age, concomitant coronary artery bypass grafting surgery, other heart valve procedures, or other major open heart procedures were excluded, as were secondary admissions for aortic valve replacement. Hospital SAVR volumes were stratified on the basis of mean annual SAVR procedures during the study period. The primary outcomes were 30-day and 1-year post-operative TAVR survival. Adjusted survival following TAVR was assessed using multivariate Cox regression.

RESULTS - A total of 65,757 SAVR and 42,967 TAVR admissions were evaluated. Among TAVR procedures, 21.7% (n = 9,324) were performed at hospitals with <100 (group 1), 35.6% (n = 15,298) at centers with 100 to 199 (group 2), 22.9% (n = 9,828) at centers with 200 to 299 (group 3), and 19.8% (n = 8,517) at hospitals with ≥300 SAVR cases/year (group 4). Compared with group 4, 30-day TAVR mortality risk-adjusted odds ratios were 1.32 (95% confidence interval: 1.18 to 1.47) for group 1, 1.25 (95% confidence interval: 1.12 to 1.39) for group 2, and 1.08 (95% confidence interval: 0.82 to 1.25) for group 3. These adjusted survival differences in TAVR outcomes persisted at 1 year post-procedure.

CONCLUSIONS - Total hospital SAVR volume appears to be correlated with TAVR outcomes, with higher 30-day and 1-year mortality observed at low-volume centers. These data support the importance of a viable surgical program within the heart team, and the use of minimum SAVR hospital thresholds may be considered as an additional metric for TAVR performance.