Pedal Medial Arterial Calcification and Its Impact on Wound Healing in Patients With Chronic Limb-Threatening Ischemia After Inframalleolar Revascularization

Background: Pedal medial arterial calcification (pMAC) has been reported as a predictor of poor clinical outcomes in patients with chronic limb-threatening ischemia (CLTI). However, the impact of pMAC in patients with CLTI undergoing endovascular therapy (EVT) for inframalleolar (IM) lesions has not been investigated. Methods: We retrospectively analyzed 365 patients with CLTI and tissue loss undergoing EVT to IM lesions between April 2010 and December 2020. Pedal medial arterial calcification in foot arteries was assessed radiologically using dorsoplantar and lateral views. The pMAC score was determined as the sum of the presence of pMAC at the following sites: (1) dorsalis pedis, (2) lateral plantar, (3) first metatarsal, (4) first toe, and (5) other toe arteries. The severity of pMAC was classified into 3 groups: no pMAC (0–1 point), moderate pMAC (2–3 points), and severe pMAC (4–5 points). The primary outcome was the 1-year cumulative incidence of wound healing, analyzed using the Kaplan–Meier analysis. Predictors of wound healing were explored using a Cox regression model. Results: One-year cumulative incidences of wound healing were 68.1%, 39.2%, and 36.7% in patients with no, moderate, and severe pMAC, respectively (log-rank p<0.001). In multivariate analysis, serum albumin < 3.0 g/dL (hazard ratio [HR] = 0.58; 95% confidence interval [CI] = 0.40, 0.86; p=0.006) and severity of pMAC (HR=0.68; 95% CI=0.52, 0.88; p=0.004, per 1-grade increase) were identified as independent predictors of wound healing. Conclusion: Pedal medial arterial calcification was significantly associated with wound healing in CLTI patients undergoing EVT for IM lesions. Clinical Impact The results of this study indicated that pedal medial arterial calcification (pMAC) was significantly associated with wound healing and major amputation in patients with chronic limb-threatening ischemia (CLTI) who underwent EVT for IM lesions. As pMAC can be assessed using only radiography, it may serve as a practical tool for risk stratification prior to revascularization procedures, aiding in treatment decisions based on wound severity. For cases with severe wounds, timely decisions regarding major amputation or a transition to palliative care may be warranted. In contrast, for cases with less severe wounds, early initiation of adjunctive therapies or intensive foot care should be considered.