Validation of the ABCD²-I score to predict stroke risk after transient ischemic attack

The primary aim of this study was to prospectively validate the predictive value of the ABCD²-I score and to then compare the predictive accuracy of the ABCD² score and ABCD²-I score for 1-year risk of stroke in admitted patients with transient ischemic attack (TIA) as defined by the World Health Organization (WHO) time-based criteria.

Data were collected from patients with transient ischemic attack within 7 days of symptom onset, and all patients underwent diffusion-weighted imaging (DWI). The predictive values of stratified 1-year rates of recurrent stroke were compared using the age, blood pressure, clinical signs, symptom duration, and ABCD² score with defined cutoff values (0-3, low-risk, 4-5, medium-risk, 6-7, high-risk) and ABCD²-I score cutoff values (0-3, low-risk, 4-6, medium-risk, 7-10, high-risk). In addition, to evaluate the performance of the two scores, we calculated the area under the curve by receiver-operating characteristic.

Four hundred and ten patients with completed DWI and 12-month follow-up with initial TIA were enrolled in this study. Of these, 111 (27.07%) patients had annual stroke risk. The risk of stroke increased with increasing ABCD² score and ABCD²-I score. The ABCD²-I score had the higher predictive value with areas under the curve of 0.77 than the ABCD² score with areas under the curve of 0.59.

The ABCD²-I score is a useful tool for stratifying the 1-year risk of stroke in TIA patients, and it improves the discriminatory power of the ABCD² score for the prediction of stroke risk.