Validating the ABCD² Score for predicting stroke risk after transient ischemic attack in the ED☆

Abstract 

Objectives

The aim of the study was to validate the use of the ABCD² score for the prediction of stroke after transient ischemic attack (TIA) in patients presenting to the emergency department (ED). The ABCD² scoring is based on 5 factors as follows: age of at least 60 years; blood pressure of at least 140/90 mm Hg; clinical features such as unilateral weakness and speech impairment alone; duration of at least 60 minutes or 10 to 59 minutes; and diabetes.

Methods

The authors conducted a retrospective observational study of all patients presented to the ED for TIA, as diagnosed by the attending emergency physicians, for a 2-year period. Sensitivity, specificity, and negative predictive value (NPV) were calculated for risk of stroke at 2, 7, 30, and 90 days after presentation.

Results

From January 1, 2005, to December 31, 2006, there were 470 patients diagnosed with TIA at the ED. Mean age was 61.0 years (SD, 13.2), with 63.3% males. Age of at least 60 years, unilateral weakness, and duration of at least 60 minutes were found to be significant predictors of stroke at 2 days. An admission rule based on an ABCD² score of at least 4 showed sensitivity of 86.4% and NPV of 91.7% for stroke at 7 days. Admission based on a score of at least 3 showed sensitivity of 96.6% and NPV of 96.1%. Admission rate was 69.1% and. 83.6%, respectively.

Conclusion

The ABCD² rule showed good sensitivity and NPV for stroke at 7 days. However, NPV was not 100%, and there would still be patients being discharged from the ED and returning with a stroke if this cutoff was implemented in our setting.