Rapid identification of high-risk transient ischemic attacks: prospective validation of the ABCD score

Abstract

Background and purpose: A 6-point score, based on age, blood pressure, clinical features, and duration (ABCD), was shown to effectively stratify the short-term risk of stroke after a transient ischemic attack (TIA). Prospective validation in different populations of patients should precede its widespread use. Whether adding computed tomography (CT) scan findings to the score would improve its performance deserves exploring. We aimed to validate the ABCD score in a prospective cohort of patients accessing Emergency Departments within 24 hours of a TIA in an area of northern Italy and to acquire preliminary data on CT-based refinement.

Methods: During a 6-month period, all TIA patients accessing the Emergency Departments of 13 Piemonte and Valle d'Aosta hospitals were prospectively enrolled and stratified according to the 6-point ABCD score and to a 7-point score (ABCDI, where I=imaging) incorporating CT findings.

Results: Of 274 patients, stroke occurred in 10 (3.6%) within 7 days and in 15 (5.5%) within 30 days. The ABCD score was predictive of stroke risk at both 7 and 30 days (odds ratio for every point of the score=2.55 at 7 days and 2.62 at 30 days; P for linear trend across the ABCD score levels=0.018 at 7 days and 0.0017 at 30 days). CT scan findings further increased prediction (odds ratio for every point of the score=2.68 at 7 days and 2.89 at 30 days; P for linear trend across the ABCDI score levels=0.0043 at 7 days and 0.0003 at 30 days).

Conclusions: The ABCD score confirmed its prognostic value in this prospective cohort. CT results could further improve prediction.