Diabetes status and long-term mortality and major amputation outcomes following revascularization in chronic limb-threatening ischemia.

BACKGROUND

Diabetes mellitus (DM) affects over 60% of patients with chronic limb-threatening ischemia (CLTI). The association between DM and 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 after LEB vs PVI for CLTI.

METHODS

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

RESULTS

Of 4218 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 = .005, and with DM: P = .004). The 5-year risk of death after LEB was 26% less than after PVI, regardless of DM status (P interaction = .490). There was no association between 5-year mortality risk and DM status (HR: 1.16, 95% confidence interval [CI]: 0.99-1.34, P = .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 the DM cohort: P = .955, and with the DM cohort: P = .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 = .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 < .001), regardless of treatment cohort (P interaction = 0.869). Similar results were seen regardless of insulin-dependent status.

CONCLUSIONS

DM affects the majority of patients with CLTI. Regardless of DM status, mortality at 5 years was lower among patients who underwent LEB. There was no difference in major amputation in LEB vs PVI and mortality or major amputation at 5 years, but patients with DM had a higher risk of major amputation than those without DM. Shared decision-making, team-based care, and integrated care offerings are needed within the context of a revascularization pathway for patients with DM.