on September 10, 2009
Published online before print September 10, 2009, doi: 10.1161/STROKEAHA.109.557074
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Submitted on May 5, 2009
From The Neurovascular Clinical Science Unit (O.C.S., A.M., L.A.K., N.H., M.M., L.K., J.D., J.M., D.H., G.H., P.J.K.), Mater University Hospital, University College Dublin, Dublin, Ireland; Connolly Hospital (P.M.E.M.), Ireland; Beaumont Hospital (A.M.), Ireland; and the School of Public Health and Population Science (L.D.), University College Dublin, Dublin, Ireland. * To whom correspondence should be addressed. E-mail: ndpss{at}mater.ie.
Background and Purpose—Transient ischemic attack (TIA) diagnosis is frequently difficult in clinical practice. Noncerebrovascular symptoms are often misclassified as TIA by nonspecialist physicians. Clinical prediction rules such as ABCD2 improve the identification of patients with TIA at high risk of early stroke. We hypothesized that the ABCD2 score may partly improve risk stratification due to improved discrimination of true TIA and minor ischemic stroke (MIS) from noncerebrovascular events. Methods—Consecutive patients with TIA were identified within a prospective population-based cohort study of stroke and TIA. The cohort was expanded by inclusion of patients with MIS and noncerebrovascular events referred to a daily TIA clinic serving the population. Diagnosis was assigned by a trained stroke physician independent of ABCD2 score. Results—Five hundred ninety-four patients were included (292 [49.2%] TIA, 45 [7.6%] MIS, and 257 [43.3%] noncerebrovascular). The mean ABCD2 score showed a graded increase across diagnostic groups (MIS mean 4.8 [SD 1.4] versus TIA mean 3.9 [SD 1.5] versus noncerebrovascular mean 2.9 [SD 1.5]; P<0.00001). The ABCD2 score discriminated well between noncerebrovascular and cerebrovascular events—TIA (c-statistic 0.68; 95% CI, 0.64 to 0.72), any vascular event (TIA+MIS; c-statistic 0.7; 95% CI, 0.66 to 0.74), and MIS (c-statistic 0.81; 95% CI, 0.75 to 0.87)—from noncerebrovascular events. Of ABCD2 items, unilateral weakness (OR, 4.5; 95% CI, 3.1 to 6.6) and speech disturbance (OR, 2.5; 95% CI, 1.6, 4.1) were most likely overrepresented in TIA compared with noncerebrovascular groups. Conclusion—The ABCD2 score had significant diagnostic usefulness for discrimination of true TIA and MIS from noncerebrovascular events, which may contribute to its predictive usefulness.
Revised on June 8, 2009
Accepted on June 16, 2009
Diagnostic Usefulness of the ABCD2 Score to Distinguish Transient Ischemic Attack and Minor Ischemic Stroke From Noncerebrovascular Events. The North Dublin TIA Study
Orla C. Sheehan MB, MRCPI;
Key words: ABCD2 score • cerebrovascular disorders • diagnosis • transient ischemic attack