Pre-Operative Ankle Brachial Index in Assessing Major Amputation Level and Outcomes in Patients With Peripheral Artery Disease.

BackgroundThe ankle brachial index (ABI) is a non-invasive tool used to assess vessel stenosis hindering limb perfusion. It is commonly used in diagnosis of peripheral artery disease (PAD). We propose that this diagnostic tool may have predictive applications in amputation level of patients with PAD and may contribute to the diagnostic evaluation of CLTI.Materials and MethodsThis study is a retrospective chart review of 97 patients with PAD admitted from 2014 to 2022 who underwent major lower extremity amputation (MLEA) at a major tertiary referral center. Patients were stratified into two groups by ABI severity (ABI ≤0.4: severe PAD, 0.4<ABI <0.9: less severe PAD). Statistical tests included Chi-square, T-test, multivariable logistic regression with collinearity statistics, and a receiver operator curve (ROC) to determine Youden's J.ResultsNinety-seven patients were included in this study, 53.6% (n = 52) of whom had less severe PAD and 46.4% (n = 45) of whom had severe PAD. Per multivariable logistic regression, more severe PAD based on ABI ≤0.4 was predictive of receiving an AKA (P = 0.013; OR = 2.833) as a primary MLEA surgery. Receiver operator curve (ROC) shows that at an ABI threshold of 0.42, the model achieves a sensitivity of 0.58 and a specificity of 0.65, yielding a Youden's J of 0.23. There was no difference in readmission, ipsilateral revision, or 5-year mortality between cohorts.DiscussionBased on our cohort of 97 patients, pre-operative ABI measurements contributed modestly to amputation level assessment within the broader clinical framework; however, ABI was not independently predictive of post-operative outcomes.