Effects of Infra-malleolar Status According to Global Limb Anatomic Staging System on Clinical Outcomes in Patients With Chronic Limb-Threatening Ischemia

Severe inframalleolar disease is an independent predictor of adverse limb outcomes after endovascular revascularization in chronic limb-threatening ischemia

OBJECTIVE

In the present study, we evaluated the effects of inframalleolar (IM) disease on the occurrence of major adverse limb events (MALE) in patients undergoing endovascular revascularization for chronic limb-threatening ischemia (CLTI).

METHODS

Patients who had undergone endovascular revascularization for CLTI between January 2015 and December 2019 at two university-affiliated hospitals were reviewed retrospectively. Patients with severe IM disease (pedal score of 2) were compared with those with mild to moderate IM disease (score of 0 or 1) using the Global Vascular Guidelines. The primary outcome was MALE (open revascularization, acute leg ischemia, major amputation). The secondary outcomes were mortality, reintervention, major adverse cardiac events, and perioperative complications ≤30 days after endovascular revascularization, primary limb-based patency, and the occurrence of any limb event (defined as any amputation, acute leg ischemia, or open revascularization). Kaplan-Meier estimates were used to compare the primary outcome, and the Cox proportion hazard model was used to assess the effects of IM disease.

RESULTS

The study included 167 limbs in 149 patients (36% female; mean age, 74 ± 12 years). Severe IM disease was identified in 71 limbs (43%). No differences were found in the baseline characteristics, except for a higher prevalence of dyslipidemia in the patients with severe IM disease (66% vs 43%; P = .003). Most patients in both groups had had a WIfI (Wound, Ischemia, foot Infection) score of 4 (severe IM disease, 64%; vs mild to moderate IM disease, 57%; P = .462) and GLASS (global limb anatomic severity scale) III anatomy (severe IM disease, 54%; vs mild to moderate IM disease, 48%; P = .752). The Kaplan-Meier estimates showed that severe IM disease was associated with lower freedom from MALE (69% vs 82%; P = .026). The Cox proportion hazard regression model showed that severe IM disease was an independent predictor of increased MALE and amputation risk (hazard ratio, 1.715; 95% confidence interval, 1.015-2.896; P = .044) after adjusting for covariates. During follow-up, patients with severe IM disease had had mortality (27% vs 31%; P = .567) and reintervention (42% vs 38%; P = .608) similar to those for patients with mild to moderate IM disease. Primary limb-based patency was also similar (79% vs 84%; P = .593) at a mean follow-up of 3.8 ± 0.8 years.

CONCLUSIONS

Severe IM disease was prevalent in 43% of limbs that had undergone endovascular revascularization for CLTI and was associated with lower freedom from MALE. Severe IM disease also independently increased the hazard of adverse limb outcomes and amputations in patients with CLTI by >70%, highlighting its importance as a measure of foot perfusion.