Among 215,335 Medicare patients undergoing transcatheter aortic valve replacement (TAVR) across 788 U.S. hospitals between 2020–2022, low-volume hospitals (≤52 procedures/year) showed 10% higher adjusted odds of 1-year all-cause mortality, stroke, and their composite compared to high-volume centers (≥102/year). Low-volume operators (≤11/year) independently elevated stroke risk by 16% and composite mortality-stroke risk by 9%, though their effect on mortality alone did not reach significance. Median annual hospital volume was 74 procedures; median operator volume just 16.
The volume-outcomes relationship in cardiac interventions is well-established for CABG and PCI, but TAVR's rapid adoption raised hopes that its streamlined technique might dilute this effect over time. This large registry analysis, drawing on linked STS/ACC TVT and CMS claims data, delivers a clear counter-argument: even in the mature contemporary TAVR era, procedural experience still meaningfully shapes patient survival at one year — not just in-hospital or at 30 days. The effect sizes, while modest in absolute terms, carry real population-level weight given TAVR's scale and aging patient demographics.
Key limitations include the observational design, which prevents causal inference; residual confounding from unmeasured site-level factors such as patient selection practices and post-discharge care quality; and Medicare-only linkage, which excludes younger or privately insured patients. Importantly, this is a preprint posted on medRxiv and has not yet been peer-reviewed — findings and effect estimates could change following expert scrutiny. For health policy, the data add weight to arguments favoring TAVR regionalization or minimum volume thresholds, a debate likely to intensify as indications continue to expand.