Abstract 13208: Pedal Arterial Calcification Score Correlates With Risk of Death and Major Adverse Cardiovascular Event in Patients With Chronic Limb Threatening Ischemia

Abstract

Introduction: Peripheral arterial disease is associated with cardiovascular morbidity and mortality, and the burden of PAD can be used to reclassify risk within CVD models. We describe a novel, practical score for quantifying peripheral arterial calcification based on plain x-ray films of the foot (MAC). We hypothesize that high MAC score is associated with risk of death and major adverse cardiovascular events (MACE; defined as MI, coronary intervention, CVA, TIA) in patients with chronic limb-threatening ischemia (CLTI). Methods: This is a single-institution retrospective study of 275 patients who underwent infrainguinal revascularization for CLTI between 1/2011 and 7/2019. MAC scores were calculated by a single blinded reviewer using two-view plain foot radiographs. Each patient was assigned a score of 0-5, with 1 point each for calcifications > 2 cm in the dorsalis pedis, plantar and metatarsal arteries, and > 1 cm in the hallux and non-hallux digital arteries. Results: The distribution of MAC scores was 0 (45%), 1 (4.7%), 2 (8.4%), 3 (18%), 4 (12%) and 5 (11%). MAC scores were trichotomized [mild (0-2), moderate (3-4), severe (5)] and higher scores were associated with male sex, DM, ESRD, and history of smoking. Median follow-up was 620 days (IQR 263-1494). Higher MAC score was significantly associated with MACE (p=0.01) and all-cause mortality (p=0.03), and was predictive of worse MACE-free survival (MACEFS; p=0.01; Figure 1 ). In a Cox Proportional Hazards model for MACEFS that included age; ESRD; CAD; history of CVA or TIA; Society for Vascular Surgery Wound, Ischemia and foot Infection (WIfI) stage; and MAC; the most severe MAC score (HR 1.8 [1.01-3.4] for MAC 5, p=0.04) was significantly associated with worse MACEFS. Conclusions: The MAC score is an independent predictor of MACE-free survival in patients with CLTI. It is a simple, quick and inexpensive tool that has the potential to stratify patients at highest risk of long-term cardiovascular complications.