CT/CT Angiography and MRI Findings Predict Recurrent Stroke after Transient Ischemic Attack and Minor Stroke: Results of the Prospective CATCH Study: Coutts SB, Modi J, Patel SK, et al. Stroke 2012; 43:1013–7.

Abstract

Acute stroke is a common and frequently disabling condition worldwide. Fifteen to thirty percent of disabling strokes are preceded by transient ischemic attacks (TIAs). After suffering a TIA there is significant risk (10%) of recurrent neurologic event in the following week, most frequently within 48 h. Magnetic resonance imaging with diffusion-weighted imaging (DWI) is known to identify patients with high risk of recurrent event after TIA. This study investigated the viability of computed tomography (CT) and CT angiography (CTA) in identifying those same patients through assessment of the intracranial and extracranial vasculature with high spatial resolution for occlusion or stenosis. The primary outcome was the first recurrent stroke event within 90 days. The secondary outcome was comparison of DWI to CT/CTA. Five hundred ten patients were enrolled in the study, of whom 237 had ischemic strokes and 232 TIAs; 11 were lost to follow-up. There were 36 primary outcome events with mean onset of 1 day. Positive CT/CTA metric was present in 24 of 36 patients with recurrent event and in 147 of 463 patients without recurrent event (hazard ratio [HR] 4.0, 95% confidence interval [CI] 2.0–8.0). Positive DWI was present in 27 of 36 patients with recurrent event and in 57 of 463 patients without recurrent event (HR 2.2, 95% CI 1.05–4.7). There was no significant difference in diagnostic accuracy between the two modalities. The authors concluded that early assessment of intracranial and extracranial vasculature with CT/CTA predicts recurrent stroke and outcome in patients with TIA and minor stroke. They also note possible advantages of CT/CTA over DWI being no difference in diagnostic accuracy, CT's widespread availability, and time to performance of study.