Coexistence of low ankle-brachial index and intra-cranial atherosclerosis?

AIM

Low ankle-brachial index (ABI<0.9) is considered a risk factor for stroke. However, there are disputes regarding the relationship between low ABI and intra-cranial atherosclerosis. The relationship between low ABI and intra/extracranial atherosclerosis was analyzed in the present study.

METHODS

Patients with large artery atherosclerosis (LAA) and small artery disease (SAD) were enrolled in this study according to the classic Trial of ORG 10172 in Acute Stroke Treatment (TOAST) subtypes. Subjects were divided into three groups: intracranial atherosclerosis (IAS), extracranial atherosclerosis (EAS) and the small artery disease group. All of the enrolled patients underwent ABI measurement and were assessed for risk factors. The association between low ABI (<0.9) and extra/intra cranial atherosclerosis were examined using logistic regression.

RESULTS

Altogether, 31.51% of LAA patients were diagnosed with peripheral artery disease, which was much higher than that of the SAD patients (19.75%, P=0.045). There was a remarkable difference in the prevalence of abnormal ABI in the EAS stenosis and IAS stenosis patients (47.17% vs. 22.31%, P=0.001). Multivariable logistic regression identified peripheral artery disease (OR=2.759, 95% CI: 1.485-5.124) and smoking (OR=2.032, 95%CI:1.093-3.779) as independent risk factors for EAS stenosis. However hypertension (OR=1.957, 95%CI: 1.119-3.421) as well as male sex (OR=2.024, 95%CI: 1.251-3.274) were found to be independent risk factors for IAS stenosis. Peripheral artery disease was not associated with IAS stenosis (OR=1.075, 95%CI: 0.516-2.238).

CONCLUSION

Intracranial atherosclerosis was not associated with a low ABI (<0.9) in the stroke patients. Low ABI is significantly associated with age (>65 years), extra-cranial atherosclerotic and diabetes mellitus. Among ischemic stroke patients, a low ABI can be useful in predicting EAS.