Attempt to determine the restrictions of ankle - Brachial index and usefulness of elevated anklebrachial index in patients treated on an internal medicine ward

Abstract

Introduction: The ankle-brachial index (ABI) is used in the screening diagnosis of peripheral artery disease (PAD). Lower limb ischemia is diagnosed if ABI≤0.9. However, persons with ABI>1.4 also suffer from leg ischemia. Not taking this into consideration may lead to diagnostic mistakes and an underestimation of cardiovascular risk. Objectives: This study addresses the analysis of clinical conditions related to an elevated ABI. Methods: One hundred and twenty-two randomly chosen subjects over 50 were treated in internal medicine ward were studied using questionnaire and ABI determination. Results: Forty-four (34%) patients had elevated ABI>1.4 and in 23 (19%) subjects ABI was≤0.9. Patients with ABI>1.4, in comparison to individuals with 0.9 1.4, lack of palpable pulse in at least one lower limb artery had a sensitivity of 6.8%, specificity of 91%, PPV of 30%, NPV of 63.4%, a likelihood ratio positive 0.75 and for negative 1.02; pulse pressure above 55mmHg had similar low diagnostic yield, respectively: 36.4%, 71.8%, 42.1%, 66.7%, 1.29 and 0.89. In logistic regression only LDL value was a significant predictive factor for elevated ABI, but with a very low odds ratio value for separate increments. Conclusion: In the diagnosis of lower limb ischemia and connected cardiovascular risk, ABI determination should be obligatory, besides atherosclerosis risk factors, peripheral pulse and pulse amplitude determination.