Abstract
Outcomes in chronic limb-threatening ischemia (CLTI) depend on timely revascularization and sustained continuity of specialty care. Although community-level socioeconomic disadvantage is associated with worse outcomes, the impact of individual-level socioeconomic vulnerability on longitudinal outcomes and healthcare utilization after CLTI revascularization remains unclear. We analyzed 333,173 Medicare beneficiaries who underwent CLTI revascularization between 2016 and 2023. Socioeconomic vulnerability was defined by Dual Enrolment (DE) in Medicaid. Outcomes were assessed using Kaplan-Meier analyses and multivariable Cox proportional hazards models. The primary clinical outcome was major amputation. A composite endpoint of major amputation or death was analyzed to contextualize overall disease burden. The study period was stratified into pre-COVID (01/2016-03/2020), COVID (03/2020-12/2021), and post-COVID (12/2021-12/2023) phases. Healthcare utilization was compared between DE and Medicare-only patients. Among included patients, 26.2% were DE. DE patients were younger, more frequently female, and had a higher comorbidity burden. The crude cumulative incidence of the primary outcome was higher in DE patients (80.1% vs. 79.7%; unadjusted HR 1.07, 95%CI 1.06-1.08), but this difference was not significant after adjustment (adjusted HR 1.00, 95%CI 0.99-1.01). DE patients had higher rates of major amputation (17.8% vs. 12.7%; adjusted HR 1.10, 95%CI 1.07-1.12), with no adjusted differences in repeat revascularization or all-cause mortality. During COVID, DE patients had a higher adjusted risk of the primary outcome (HR 1.05, 95%CI 1.02-1.08), whereas risks were similar pre- and post-pandemic. DE identifies CLTI patients at increased risk of limb loss despite similar adjusted survival, highlighting individual-level barriers to care continuity and the need for targeted strategies to reduce preventable amputations.