BACKGROUND: Frailty is common among surgical patients and predicts poor surgical outcomes. This study aimed to analyze transitions in frailty state among patients undergoing lower extremity care for chronic limb-threatening ischemia (CLTI). METHODS: Between 2018 and 2022, all patients undergoing a primary intervention for CLTI (endovascular intervention [EV], bypass [BYP], major amputation [AMP]) or wound care were analyzed. Frailty was assessed by Vascular Quality Initiative-derived Risk Analysis Index. Frailty was defined as a Vascular Quality Initiative-derived Risk Analysis Index score of ≥35. Transition in frailty state between preoperative and follow-up measurement at 1 month and 1 year were analyzed. Patient characteristics leading to a transition in frailty state were analyzed using multivariable Cox regression analysis. Amputation-free survival (survival without AMP) and freedom from major adverse limb events (above-ankle amputation of the index limb or major re-intervention (new BYP graft, jump/interposition graft revision) were evaluated. RESULTS: We included 1859 patients (56% male
mean age, 65 ± 11 years) who underwent either EV (52%), a BYP (29%), AMP (13%), or wound care (6%). Amon them, 25% were considered frail on initial evaluation (28%, 16%, 32%, and 30% EV, BYP, AMP, and wound care, respectively). At 30 days, overall frailty increased to 34%: 13% of patients moved from nonfrail to frail (9%, 18%, 22%, and 5% for EV, BYP, AMP, and wound care, respectively), and 4% of patients moved from frail to nonfrail (6%, 2%, 1%, and 0% for EV, BYP, AMP, and wound care, respectively). At 1 year, overall frailty increased to 40%: an additional 13% of patients shifted from nonfrail to frail (15%, 6%, 23%, and 8% for EV, BYP, AMP, and wound care, respectively), and 5% of patients shifted from frail to nonfrail (4%, 8%, 2%, and 0% for EV, BYP, AMP, and wound care, respectively). At 1 year, frailty increased by 28% in EV, 16% for BYP, 32% in AMP, and 43% in wound care. Frailty at baseline, 30 days, and 1 year was associated with a high Charlson's Comorbidity Index. Shifting to a frail state postoperatively was associated with decreased survival and a lower amputation-free survival at 1 year. CONCLUSIONS: After major interventions for CLTI at 1 year, 27% of patients shift from a nonfrail to a frail state, and 9% of patients shift from a frail to a nonfrail state with differences across modalities in comparison to wound care, where 13% of patients moved from a nonfrail to a frail state, and none shifted from a frail to a nonfrail state. Shifting to a frail state after intervention is associated with poor outcomes and should be considered when evaluating and intervention in a patient with CLTI.