Diabetes Status and Long-Term Mortality and Major Amputation Outcomes Following Revascularization in Chronic Limb Threatening Ischemia.

Abstract

Introduction: Diabetes mellitus (DM) affects over 60% of patients with chronic limb-threatening ischemia (CLTI). The association between DM in outcomes after lower-extremity bypass (LEB) or peripheral vascular interventions (PVI) remains unclear. Our study aims to assess the association between DM and 5-year all-cause mortality and major amputation following LEB vs. PVI for CLTI.

Methods: Patients with CLTI undergoing LEB or PVI between 2014-2019 were studied in the VQI registry and stratified according to DM status. Outcomes were derived from linked Medicare claims data. Propensity score 1:1 matching between PVI and LEB cohort was used. Cumulative incidence of mortality and hazard ratio were assessed with a Kaplan-Meier and Cox regression model, respectively. To account for the competing risk of death, major amputation was evaluated with Aalen-Johansen and Fine-Gray model for cumulative incidence and sub-hazard ratio (sHR), respectively. The interaction between DM and PVI vs LEB was tested.

Results: Of 4,218 patients were included (70.7 ± 10.7 years old, 30.6% female), 62.3% had DM. . The 5-year cumulative incidence of death was lower in LEB vs PVI regardless of DM status (LEB vs. PVI without DM: P=0.005, and with DM: P = 0.004). The 5-year risk of death after LEB was 26% less than after PVI, regardless of DM status (P interaction = 0.490). There was no association between 5-year mortality risk and DM status (HR 1.16 95% CI 0.99-1.34, P = 0.060). The cumulative incidence of major amputation at 5 years did not differ in LEB vs. PVI regardless of DM status (LEB vs. PVI without DM cohort: P = 0.955, and with DM cohort: P=0.955). The 5-year risk of major amputation was not associated with the type of revascularization (sHR 0.79 95% CI 0.57-1.08, P=0.140). Major amputation was twice higher in patients with DM than in those without DM (sHR 1.98 95% CI 1.55-2.54, P< 0.001), regardless of treatment cohort (P interaction = 0.869). Similar results were seen regardless of insulin-dependent status.

Conclusion: DM affects the majority of patients with CLTI. Regardless of DM status, mortality at 5 years was lower among patients undergoing LEB. There was no difference in major amputation in LEB vs PVI and mortality or major amputation at 5 years, but patients with DM vs. no DM had a higher risk of major amputation. Shared decision-making, team-based care, and integrated care offerings are needed within the context of a revascularization pathway for patients with DM.