One-year clinical outcomes of delayed referral and subsequent management in chronic limb-threatening ischemia.

Abstract

This study assessed the effect of delayed referral on clinical outcomes in individuals with chronic limb-threatening ischemia, characterized associated patient factors, and explored real-world reasons for referral delays in Japan. The current study involved a multicenter, retrospective registry of 815 individuals with chronic limb-threatening ischemia who underwent endovascular therapy between March 2021 and December 2023. Individuals were categorized into early referral (<1 month from wound onset to a vascular specialist) and delayed referral (≥1 month) groups. The primary end point was 1-year wound healing. Secondary end points included time to wound healing and amputation-free survival. Multivariate logistic regression was used to identify factors associated with delayed referral. Reasons for delay were also assessed qualitatively. Of 815 individuals, 432 were in the early referral group and 383 in the delayed group. Baseline characteristics were generally similar; however, the delayed group included more current smokers (17.4% vs 26.1%, P = .003) and fewer individuals on dialysis (56.9% vs 48.2%, P = .014). Delayed referral was associated with more advanced wounds (Wound, Ischemia, and foot Infection stage, P = .019). One-year wound healing was significantly lower in the delayed group (59.8% vs 77.0%, P < .001), with longer healing time (median 100 vs 87.5 days, P = .037) and lower amputation-free survival (58.1% vs 67.6%, P = .016). Multivariate analysis identified current smoking (odds ratio [OR]: 1.58, 95% confidence interval [CI]: 1.12-2.22, P < .01), absence of dialysis (OR: 0.72, 95% CI: 0.54-0.95, P = .02), and high-risk Wound, Ischemia, and foot Infection stage (OR: 1.50, 95% CI: 1.13-1.98, P < .01) as independent factors associated with delayed referral. Among delayed cases, 51.4% were due to provider-related reasons and 35.8% to patient-related reasons. Among individuals with chronic limb-threatening ischemia, delayed referral was independently associated with worse 1-year outcomes, including lower wound-healing rates and amputation-free survival. Behavioral and system-level factors, such as smoking status and dialysis care, significantly influenced referral timing. Earlier identification of tissue loss and structured collaboration among primary care, dialysis units, and vascular specialists are essential to optimize limb outcomes in high-risk populations.