Immunologic profiles in patients with chronic limb-threatening ischemia undergoing endovascular revascularization

Background: Inflammation and immune dysregulation have been associated with adverse outcomes in cardiovascular disease. There is limited understanding of the association of different profiles of white blood cell (WBC) subsets and red cell distribution width (RDW) in patients with chronic limb-threatening ischemia (CLTI). Methods: Patients with CLTI undergoing endovascular revascularization in our single-center, tertiary care hospital from 2017 to 2019, who had a preceding complete blood count (CBC) with WBC differentials (n =213), were included in the analysis. Patient characteristics, laboratory values, and clinical outcomes were collected. Cox proportional hazards regression models were used to assess for associations between all-cause mortality and leukocyte subset; multivariate analysis was used to account for confounders. Kaplan–Meier curves were generated to depict survival censored at 1 year postrevascularization using baseline CBC indices. Results: Adjusting for confounders, elevated RDW was associated with increased mortality (continuous per % increase, adjusted hazard ratio [HR] 1.33, p < 0.001). Baseline lymphopenia was associated with mortality in univariate analysis. Other leukocyte subtypes were not associated with mortality outcomes in our population. Exploratory analysis showed negative deflections in ∆WBC from pre- to postprocedure day 1 were affiliated with increased mortality when adjusted for age, sex, race, chronic kidney disease, and baseline hemoglobin (∆WBC HR 1.16, p = 0.004). Further exploratory analysis showed an association between RDW and all-comers readmission. Conclusions: The utilization of a periprocedural WBC subset differential can be a useful adjunct to risk-stratify patients with CLTI undergoing endovascular revascularization. Further studies are needed to understand potential ways to modulate immune dysregulation so as to improve mortality outcomes.