Early stroke risk and ABCD2 score performance in tissue- vs time-defined TIA: a multicenter study

Neurology. 2011 Sep 27;77(13):1222-8. doi: 10.1212/WNL.0b013e3182309f91. Epub 2011 Aug 24.

Abstract

Objectives: Stroke risk immediately after TIA defined by time-based criteria is high, and prognostic scores (ABCD2 and ABCD3-I) have been developed to assist management. The American Stroke Association has proposed changing the criteria for the distinction between TIA and stroke from time-based to tissue-based. Research using these definitions is lacking. In a multicenter observational cohort study, we have investigated prognosis and performance of the ABCD2 score in TIA, subcategorized as tissue-positive or tissue-negative on diffusion-weighted imaging (DWI) or CT imaging according to the newly proposed criteria.

Methods: Twelve centers provided data on ABCD2 scores, DWI or CT brain imaging, and follow-up in cohorts of patients with TIA diagnosed by time-based criteria. Stroke rates at 7 and 90 days were studied in relation to tissue-positive or tissue-negative subcategorization, according to the presence or absence of brain infarction. The predictive power of the ABCD2 score was determined using area under receiver operator characteristic curve (AUC) analyses.

Results: A total of 4,574 patients were included. Among DWI patients (n = 3,206), recurrent stroke rates at 7 days were 7.1%(95% confidence interval 5.5-9.1) after tissue-positive and 0.4% (0.2-0.7) after tissue-negative events (p diff < 0.0001). Corresponding rates in CT-imaged patients were 12.8% (9.3-17.4) and 3.0% (2.0-4.2), respectively (p diff < 0.0001). The ABCD2 score had predictive value in tissue-positive and tissue-negative events (AUC = 0.68 [95% confidence interval 0.63-0.73] and 0.73 [0.67-0.80], respectively; p sig < 0.0001 for both results, p diff = 0.17). Tissue-positive events with low ABCD2 scores and tissue-negative events with high ABCD2 scores had similar stroke risks, especially after a 90-day follow-up.

Conclusions: Our findings support the concept of a tissue-based definition of TIA and stroke, at least on prognostic grounds.

Publication types

  • Multicenter Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Area Under Curve
  • Cohort Studies
  • Diffusion Magnetic Resonance Imaging
  • Female
  • Humans
  • International Cooperation
  • Ischemic Attack, Transient / diagnosis*
  • Male
  • Predictive Value of Tests
  • Risk Factors
  • Severity of Illness Index*
  • Statistics, Nonparametric
  • Stroke / diagnosis
  • Time Factors
  • Tomography, X-Ray Computed