Correlation of ABCD2 Score with Degree of Internal Carotid Artery Stenosis: An Observational Pilot Study

Abstract

ABCD(2) is a validated scoring system that predicts the risk of stroke after a transient ischemic attack (TIA). International guidelines suggest that patients with a low score can be investigated on an outpatient basis. The ABCD2 score, however, cannot identify which patients have significant internal carotid artery (ICA) disease, and this group of patients could benefit from rapid access carotid endarterectomy (RACE). Studies have shown that patients with significant carotid artery disease have a higher risk of neurologic events or recurrent stroke. The aim of this study was to document the range of ABCD2 scores in patients with carotid artery-related TIA, and investigate any correlation between the ABCD2 scores and ICA stenosis. Patients undergoing carotid duplex ultrasound scan for TIA from January 2009 to May 2010 from two vascular units were identified from the vascular database retrospectively. Clinical notes were reviewed and outcomes measures were recorded: ABCD2 scores (age, blood pressure, clinical features, diabetes, and duration) and carotid plaque morphology. Ninety-seven patients with a mean age of 74 (range 56-90) years had ICA stenoses of ≥50% up to 100%. Fifty-seven patients had an ABCD2 score of ≤4. There was no significant correlation between ABCD2 scores and degree of ICA stenosis nor carotid plaque morphology (P=0.2, r=1.0, and P=1.0, r=0.0007, respectively). Because no correlation between ABCD2 scores and the degree of ICA stenosis was found, all patients with carotid territory TIA should undergo urgent imaging of the carotid arteries because a high proportion of these patients may benefit from RACE.