Diabetes Interacts with Latinx/Hispanic Ethnicity to Increase Major Amputations After Peripheral Vascular Intervention for Chronic Limb-threatening Ischemia

Abstract

Latinx/Hispanic patients treated for chronic limb-threatening ischemia (CLTI) have higher amputation rates after controlling for presenting Wound, Ischemia, and foot Infection (WIfI) status. We hypothesize that a higher incidence of diabetes mellitus (DM) in Latinx/Hispanic patients may contribute to this disparity. The Vascular Quality Initiative peripheral vascular intervention dataset (2016-2022) was queried for CLTI. Inclusion criteria were reported WIfI stage and White race or Latinx/Hispanic ethnicity. The primary endpoint was 1-year major amputation (through tibia/fibula or more proximally). A multivariate hierarchical Fine Gray analysis was performed controlling for hospital-level variation and competing risk of death. The analysis was stratified by WIfI stage, and DM was treated as an interaction term with race and ethnicity. Overall, 38,079 (45%) cases met inclusion criteria and 3247 (12%) were Latinx/Hispanic with a higher incidence of DM in Latinx/Hispanic patients (77% vs 61%; P < .01). Proportions of WIfI stages were similar between White race and Latinx/Hispanic ethnicity, respectively: stage 1 (29% vs 30%), stage 2 (38% vs 32%), stage 3 (19% vs 21%), and stage 4 (14% vs 18%). The cumulative incidence of major amputation was highest for Latinx/Hispanic patients with DM (Figure). On multivariate analysis, the 1-year subdistribution hazard ratio (SHR) for amputation was highest for Latinx/Hispanic patients with DM at 1.8 (95% confidence interval [CI], 1.3-2.4; P < .01); and 1.4; 95% CI, 0.7-2.6; P = .29) for Latinx/Hispanic without DM, and 1.4 (95% CI, 1.1-1.6; P < .01) for White race with DM compared to White race without DM. When stratified by WIfI stage, the interaction of Latinx/Hispanic ethnicity with DM conferred the greatest increase in 1-year SHR for WIfI stages 2 (SHR, 1.9; 95% CI, 1.1-3.2; P = .03) and 3 (SHR, 2.1; 95% CI, 1.2-3.7; P < .01), compared to White race without DM. Latinx/Hispanic ethnicity requiring insulin treatment for DM had the highest hazard of amputation (SHR, 2.0; 95% CI, 1.4-2.7; P < .01) (Table). The increase in major amputations for Latinx/Hispanic patients after peripheral vascular intervention for CLTI is modified by the interaction with DM with a stepwise increase for those requiring insulin treatment. This study suggests that DM prevention and treatment is a cornerstone in addressing disparities for Latinx/Hispanic patients with limb threat and reducing their amputation risk.TableSubdistribution hazard ratios (SHR) by diabetes mellitus (DM) TreatmentSHR95% CIP valueWhite racea Diet controlled0.80.5-1.2.29 Noninsulin treatment1.20.9-1.6.07 Insulin treatment1.51.2-1.8<.01Latinx/Hispanic ethnicitya No DM diagnosis1.40.8-2.6.29 Diet controlled1.50.6-3.8.26 Noninsulin treatment1.50.9-2.5.09 Insulin treatment2.01.4-2.7<.01CI, Confidence interval.Model adjusted for age, primary insurer, WIfI stage, end-stage renal disease, prior amputation, and intervention level. Boldface entries indicate statistical significance.aReference group for all: White race with no DM diagnosis. Open table in a new tab