Plenary Session Presentation at the Vascular and Endovascular Surgical Society 28th Annual Winter Meeting; Sun Valley Resort, Sun Valley, ID January 18 - 21, 2024 ObjectivesIn 2021, Ferraresi et al. created a novel scoring system based on the impact of small artery disease (SAD) and medial arterial calcification (MAC) on wound healing. SAD and MAC scores functioned similar to WIfI but with minimal resource expenditure. Despite its potential, few studies have expanded on the original dataset. We aim to validate SAD and MAC’s impact on wound healing outcomes and determine their utility in relation to current predictive models. MethodsSingle-institution retrospective review was used to identify amputations for chronic (>1mo) podiatric wounds between 2015-2020. Foot x-ray (MAC) or angiography (SAD) <6 months of index procedure was required. Primary outcomes included major amputation, wound healing, major adverse limb events (MALE), and amputation-free survival (AFS). Statistical analysis included chi-square, one-way ANOVA, non-parametric correlation, Kaplan-Meier, Cox regression, and Akaike (AIC)/ Bayesian Inclusion Criteria (BIC) model comparison. ResultsOf 136 limbs, 67 received SAD scores (0-2) and 128 received MAC scores (0-2). SAD cohorts exhibited similar comorbidity profiles with exception of coronary disease, heart failure, and chronic kidney disease. MAC cohorts were notably disparate in prevalence of multiple conditions. High mean SAD/MAC scores were seen in severe (3-vessel) below-ankle disease (p=.001* [SAD], p=.041* [MAC]). Both SAD and MAC correlated with lower mean toe pressure (p=.043* [SAD], p=<.001* [MAC]), while only MAC correlated with higher overall WIfI score (p=.029*). No significant procedural differences were noted. However, higher re-admission rates (73.9% [2] vs. 46.9% [0], p=.014*) and all-cause mortality (65.2% [2] vs. 26.0% [0], p=.002*) were noted with higher MAC. Survival analysis revealed higher one-year major amputation rates (p=.036*), impaired wound healing (p<.001*), and lower amputation-free survival (p=.001*) with increasing MAC severity. Additionally, MAC-2 patients underwent amputation at faster rates than MAC-0 patients (HR 5.25, 95% CI [1.82, 9.77]) with longer times to wound healing (HR 0.21, 95% CI [0.08, 0.53]). Model comparison suggested a combination of WIfI and MAC could improve accuracy of predicted time to major amputation, wound healing, and amputation-free survival. ConclusionsMAC scoring showed significant promise both as individual predictor and adjunct to current predictive models of long-term wound healing outcomes. Routine use of MAC scoring in CLTI evaluation, especially when non-invasive testing is unavailable, could promote timely referral for intervention and efficient resource utilization in limited-resource or critical care settings. Further investigation is necessary to determine MAC’s impact on revascularization and how scoring can be used to guide surgical decision making.