The sensitivity and specificity of ankle brachial index in diagnosis of lower extremity arterial disease in the patients with high cardiovascular risk / 中华老年医学杂志

ABSTRACT

Objective To prospectively evaluate the sensitivity and specificity of ankle brachial index (ABI) in the diagnosis of lower extremity arterial disease(LEAD)by using conventional digital subtraction angiography (DSA) as the reference standard, and to research the threshold value of ABI screening test for diagnosis. Methods A total of 383 consecutive patients (245 men and 138 women, mean age (64.1±11.7) years] underwent conventional DSA and ABI measurement. Receiver operator characteristics (ROC) analysis was performed to assess possible threshold values for predicting the LEAD in these patients. Results Conventional DSA was used as the gold standard in defining≥50% luminal stenosis for the diagnosis of LEAD. 0. 95 was the overall cutoff of ABI which was associatcd with 93.0% sensitivity, 85.0% specificity, 8.81 positive likelihood ratio(+LR) and 0. 23 negative likelihood ratio(-LR) for detection of hemodynamically significant stenosis (lesions>≥50%) in all 383 subjects (P<0.01). The area under the ROC curve was 0. 953(95%CI 0.920～0.985). Conclusions ABI measurement is an accurate and reliable non-invasive alternative to conventional DSA in the diagnosis of lower extremity arterial disease. And the cut-off 0.95 is the threshold ABI value for detecting LEAD in Chinese population.