腎動脈ステント留置術の処置傾向と人種間格差：全国コホートにおける検討

Atherosclerotic renal artery stenosis (RAS) affects nearly 7% of adults over age 65 and is associated with increased cardiovascular and renal morbidity. Although early observational studies suggested benefit from renal artery stenting, subsequent randomized trials failed to show improvement in major clinical endpoints, contributing to substantial declines in procedural use. To characterize contemporary practice, we conducted a retrospective cohort study of Medicare beneficiaries older than 65 years who underwent renal artery stenting for atherosclerotic RAS between 2016 and 2020. Using Medicare claims data, we evaluated baseline characteristics, temporal utilization, and post-procedural outcomes, stratified by race, geographic region, and dual Medicare-Medicaid enrollment status. Among 19,130 patients, the mean age was 76.0 years (±6.4), 59.2% were female, and 90.3% were White; 84.2% had chronic kidney disease and 48.7% had heart failure. Procedural rates declined by 41.1% over the study period. Compared with White patients, Black patients had higher adjusted risks of hypertensive crisis hospitalization (aHR 1.45, 95% CI 1.24-1.70) and dialysis initiation (aHR 1.78, 95% CI 1.39-2.27); patients of Other races also had greater risk of dialysis initiation (aHR 1.98, 95% CI 1.50-2.63). Patients in the South experienced higher unadjusted cardiovascular event rates (50.0%) but similar adjusted mortality compared with those in the Northeast (aHR 1.09, 95% CI 0.98-1.21). Dual enrollment was associated with increased all-cause mortality (aHR 1.31, 95% CI 1.20-1.43). In conclusion, renal artery stenting rates continued to decline in recent years, and contemporary recipients constitute an older, comorbid population with substantial cardiovascular risk. Outcomes differed markedly by race, socioeconomic status, and geography, highlighting the need for improved risk stratification and prospective evaluation of stenting in high-risk cohorts.