The incidence and clinical predictors of acute infarction in patients with transient ischemic attack using MRI including DWI.

INTRODUCTION

According to the most recent definition of transient ischemic attack (TIA) and the recommendations of the American Heart Association, magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI) is considered a mandatory tool in evaluating and treating patients with TIA. This study aims to determine the incidence of TIA-related acute infarction, identify the independent predictors of acute infarction, and investigate the correlation between acute infarction detected by DWI-MRI and stroke risk during hospitalization.

METHODS

Over a 36-month period (starting November 2007), all TIA patients (symptom duration of <24 h) who were admitted to hospital within 48 h of symptom onset and who underwent DWI-MRI were included in this population-based prospective study. The incidence of acute infarction, clinical predictors, and association with stroke recurrence during hospitalization were studied.

RESULTS

Of 1,910 patients (mean age, 66.7 ± 13 years; 46 % women), 1,862 met the inclusion criteria. A TIA-related acute infarction was detected in 206 patients (11.1 %). Several independent predictors were identified with logistic regression analysis: motor weakness [odds ratio (OR), 1.5], aphasia (OR, 1.6), National Institutes of Health Stroke Scale (NIHSS) score of ≥10 at admission (OR, 3.2), and hyperlipidemia (OR, 0.6). Of 24 patients (1.3 %) who suffered a stroke during hospitalization (mean, 6 ± 4 days), five had positive DWI. Stroke rate during hospitalization was nonsignificantly higher in patients with positive DWI than those with negative DWI (2.4 vs 1.1 %, respectively; P = 0.12).

CONCLUSION

The evidence of acute infarction by DWI-MRI in TIA patients was detected in 11.1 % of patients and associated with motor weakness, aphasia, and NIHSS score of ≥10 at admission.