Pedal medial arterial calcification influences the outcomes of isolated infra-malleolar interventions for chronic limb-threatening ischemia

Background Infra-malleolar disease is present in most diabetic patients presenting with tissue loss. Infra-malleolar (pedal) artery disease and pedal medial arterial calcification (pMAC) are associated with major amputation in patients with chronic limb-threatening ischemia (CLTI). This study aimed to examine the impact of pMAC on the outcomes after isolated infra-malleolar (pedal artery) interventions. Methods A database of lower extremity endovascular intervention for tissue loss patients between 2007 and 2022 was retrospectively queried. Patients with CLTI were selected, and those undergoing isolated infra-malleolar intervention on the dorsalis pedis and medial and lateral tarsal arteries and who had foot x-rays were identified. X-rays were assessed blindly for pMAC and scored on a scale of 0-5. Patients with concomitant superficial femoral artery (SFA) and tibial interventions were excluded. Intention to treat analysis by the patient was performed. Amputation-free survival (AFS; survival without major amputation) was evaluated. Results 223 patients (51% female, 87% Hispanic, average age 66 years; 323 vessels) underwent isolated infra-malleolar intervention for tissue loss. All patients had diabetes, 96% had hypertension, 79% had hyperlipidemia, and 63% had chronic renal insufficiency (55% of these were on hemodialysis). Most of the patients had WIfI stage 3 disease and had various stages of pMAC: severe (score=5) in 48%, moderate (score = 2-4) in 31%, and mild (score = 0-1) in 21% of the patients. Technical success was 94%, with a median of 1 vessel treated per patient. All failures were in severe pMAC. Overall, Major Adverse Cardiovascular Events (MACE) was 0.9% at 90 days after the procedure. Following the intervention, most patients underwent a planned forefoot amputation (single digit, multiple digits, ray amputation, or trans-metatarsal amputation). WIfI ischemic grade was improved by 51%. Wound healing at three months was 69%. Those not healing underwent below-knee amputations (BKA). The overall 5-yr-AFS rate was 35±9%. The severity of pMAC was associated with decreased AFS. Conclusions PMAC influences the technical and long-term outcomes of Infra-malleolar intervention in diabetes. Severe pMAC is associated with amputation and should be considered as a variable in the shared decision-making of diabetic patients with CLTI.