Validation of the ABCD score in identifying individuals at high early risk of stroke after a transient ischemic attack: a hospital-based case series study

Abstract

Background and purpose: A simple score derived in the Oxfordshire Community Stroke Project (ABCD score) was able to identify individuals at high early risk of stroke after a transient ischemic attack (TIA) both in a population-based and a hospital-referred clinic cohort. We aimed to further validate the former score in a cohort of hospitalized TIA patients.

Methods: We retrospectively reviewed the emergency room and hospital records of consecutive patients hospitalized in our neurological department with a definite TIA according to the World Health Organization (WHO) criteria during a 5-year period. The 6-point ABCD score (age [<60 years=0, > or =60 years=1]; blood pressure [systolic < or =140 mm Hg and diastolic < or =90 mm Hg=0, systolic >140 mm Hg and/or diastolic >90 mm Hg=1]; clinical features [unilateral weakness=2, speech disturbance without weakness=1, other symptom=0]; duration of symptoms [<10 minutes=0, 10 to 59 minutes=1, > or =60 minutes=2]) was used to stratify the 30-day stroke risk.

Results: The 30-day risk of stroke in the present case series (n=226) was 9.7% (95% CI, 5.8% to 13.6%). The ABCD score was highly predictive of 30-day risk of stroke (ABCD=0 to 2: 0%, ABCD=3: 3.5% [95% CI, 0% to 8.2%], ABCD=4: 7.6% [95% CI, 1.2% to 14.0%], ABCD=5: 21.3% [95% CI, 10.4% to 33.0%], ABCD=6: 31.3% [95% CI, 8.6% to 54.0%]; log-rank test=23.09; df=6; P=0.0008; P for linear trend across the ABCD score levels <0.00001). After adjustment for stroke risk factors, history of previous TIA, medication use before the index TIA, and secondary prevention treatment strategies, an ABCD score of 5 to 6 was independently (P<0.001) associated with an 8-fold greater 30-day risk of stroke (hazard ratio, 8.01; 95% CI, 3.21 to 19.98).

Conclusions: Our findings validate the predictive value of the ABCD score in identifying hospitalized TIA patients with a high risk of early stroke and provide further evidence for its potential applicability in clinical practice.