Correlation of Ankle-Brachial Pressure Index (ABPI) and Clinical Findings With Duplex Scan for the Assessment of Peripheral Arterial Disease

Background and objective Peripheral arterial disease (PAD) is a common manifestation of systemic atherosclerosis and a powerful predictor of coronary and cerebrovascular events, yet it is frequently underdiagnosed, particularly in primary care and resource-limited settings. The ankle-brachial pressure index (ABPI) is an inexpensive, noninvasive, first-line test, whereas arterial duplex ultrasonography provides anatomical and hemodynamic information that can guide revascularization. The objective of this study was to correlate the ABPI and clinical findings with arterial duplex scan findings in the evaluation of lower-limb PAD. Materials and methods This descriptive cross-sectional study enrolled 50 patients with clinically suspected chronic lower-limb arterial occlusive disease admitted to the Department of Surgery, Dhaka Medical College Hospital, between September 2018 and March 2019. All patients underwent history taking, clinical examination, ABPI measurement, and arterial duplex ultrasonography of the affected limb. An ABPI of 0.90 or less, supported by clinical findings, was considered positive for PAD, and stenosis or occlusion on duplex was taken as the imaging finding of interest. Agreement between ABPI plus clinical findings and duplex was assessed, and the corresponding diagnostic performance was calculated. Analyses were performed using IBM SPSS Statistics for Windows, version 20.0 (released 2011; IBM Corp., Armonk, NY, USA), with P < 0.05 considered statistically significant. Results The mean age was 53.4 ± 11.5 years, and 82.0% of patients were male (male-to-female ratio, 4.5:1). Smoking (88.0%) was the most frequent risk factor, followed by diabetes mellitus (64.0%), hypertension (58.0%), and obesity (44.0%). Intermittent claudication and muscle cramping (68.0% each) were the most common symptoms, and all patients had tissue loss (gangrene or ulceration). ABPI indicated moderate disease (0.41-0.70) in 38.0% of patients, mild disease (0.71-0.90) in 28.0%, and severe disease (<0.40) in 16.0%. Duplex demonstrated stenosis or occlusion in 76.0% of patients. ABPI combined with clinical findings showed a sensitivity of 90.2%, specificity of 88.9%, positive predictive value of 97.3%, and overall accuracy of 90.0%, with a statistically significant association with duplex findings (P = 0.0001). Conclusions ABPI combined with clinical assessment correlated strongly with duplex ultrasonography and provided an accurate, accessible approach to the diagnosis of lower-limb PAD. The combined use of physiological and imaging data supports earlier diagnosis and rational treatment planning, an advantage that is especially relevant in resource-limited settings.