The impact of diabetes mellitus on the outcomes of revascularization for chronic limb-threatening ischemia in the BEST-CLI trial

Objective: Several observational studies have demonstrated an association between diabetes mellitus (DM) and above-ankle amputation after lower extremity revascularization (LER). However, data from prospective randomized trials is lacking. This analysis compares the outcomes of patients with and without DM enrolled in the Best Endovascular vs Best Surgical Therapy in patients with Chronic Limb-Threatening Ischemia (BEST-CLI) trial. Methods: Baseline characteristics were compared between patients with and without DM in the BEST-CLI trial. Cox regression was used to determine the association between DM and major outcomes of major adverse limb events (MALE), reintervention, above-ankle amputation, and all-cause death. Results: Among 1777 patients who underwent LER, 69.2% had DM. Compared with patients without DM, those with DM were significantly younger, less likely to be White, and more likely to be Hispanic. Patients with DM were more likely to have hypertension, hyperlipidemia, coronary artery disease, congestive heart failure, and renal disease and be on optimal medical therapy (antiplatelets and statins), whereas patients without DM were significantly more likely to be smokers and have chronic obstructive pulmonary disease. Patients with DM were significantly more likely to present with late Wound Ischemia foot Infection (WIfI) stages (3-4) (73.7% vs 45.9%; P < .001) that were driven predominantly by differences in wound and infection grade. Conversely, patients without DM had significantly lower ankle pressures and toe pressures and were significantly more likely to have WIfI ischemia grade 3 compared with patients with DM (60% vs 52.5%; P = .016). At 3 years, patients with DM exhibited higher rates of above-ankle amputation and all-cause death compared with patients without DM. Kaplan-Meier analysis demonstrated significantly higher MALE or all-cause death compared with patients without DM (3-year estimate: 53.5% vs 46.4%; P < .001). After adjusting for potential confounders, regression analysis demonstrated that DM was independently associated with increased above-ankle amputation (1.75 [1.22-2.51]), all-cause death (1.63 [1.31-2.03]), and MALE or all-cause death (1.24 [1.04-1.47]). Conclusions: Patients with DM undergoing LER for chronic limb-threatening ischemia experienced a greater incidence of MALE or all-cause death compared with patients without DM. The impact of DM seems to be mediated by more severe wounds and infections at the time of presentation, and a higher prevalence of cardiac and renal disease.