Validation of the ABCD score in identifying individuals at high early risk of stroke after a transient ischemic attack

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, >= 60 years = 1]; blood pressure [systolic <= 140 mm Hg and diastolic <= 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, >= 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.