Inter-limb blood pressure difference, ankle-brachial index and its association with border zone cerebral infarcts: A prospective single-blind study from central India

Abstract

Background: Border zone infarcts (BZI) are ischemic lesions occurring between two non- anastomosing arterial territories. BZI patients have higher incidence of recurrent strokes (RS). The predictors of peripheral arterial disease (PAD), low ankle-brachial index (ABI) and high inter-arm blood pressure difference (IABD) are associated with intracranial atherosclerosis and thus, could also have an association with BZI. Our single blind prospective study explores the predictive value of these clinical variables, ABI and IABD for BZI in patients with acute ischemic stroke. Methods: The subjects fulfilling the inclusion criterion (183 of 335, 78.14% men) were divided into BZI (n=89) and pure core arterial territory infarct (CATI, n=94) groups, based upon MRI characteristics of infarcts. The value of ABI (<1 or ≥1) and IABD (<10 or ≥ 10 mmHg) was deduced in all the subjects. The groups were compared using the clinical features, ABI and IABD values as variables. Results: Odds for BZI were high in men (OR 1.78, 95% CI 0.87-3.66), hypertension (p=0.003, OR 2.79, 95% CI 1.39 to 5.6), history of ischemic heart disease (OR 2.06, 95%CI 0.73-5.8), prior stroke (OR 1.92, 95% CI 0.54-6.8), smoking (OR1.85, 95% CI 0.96-3.56) and dyslipidemia (OR2.5, 95% CI 0.83-7.58). ABI mean (ABI-M) <1 was significantly associated with BZI (p=0.022) as compared to CATI. ABI-M of <0.96 was able to diagnose BZI over CATI (sensitivity 56.2%, specificity 63.8%, p<0.05).IABD ≥10 mm Hg showed no association with BZI. Logistic regression analysis showed that HTN (p<0.001) and low ABI-M (p<0.033) were a significant predictor of BZI. Conclusion: Low ABI-M could be of value as a screening tool to identify persons at risk for BZI in stroke population.

Keywords

• border-zone infarct
• ankle-brachial index
• inter-arm blood pressure difference
• stroke
• intracranial arterial stenosis
• peripheral arterial disease
• hypertension