Early CT Angiography Identifies Recurrent Stroke Risk

Use of CT/CT angiography (CTA) as soon as possible in patients presenting with transient ischemic attacks (TIA) or minor stroke predicts risk of recurrent stroke and clinical outcome, according to a study published online in Stroke: Journal of the American Heart Association.

Although MRIs are frequently used for early assessment, CT scanners are usually more readily available to the emergency department, said the study authors. The median waiting time for diffusion-weighted MRI was 17.5 hours, but for CTA imaging, the wait was only 5.5 hours. In addition, CTA does not take much time, adding only five minutes to the standard CT brain scan.

It is estimated that there is a 10 percent risk of recurrent stroke within 90 days of a patient experiencing a TIA or minor stroke, with the majority recurrent strokes occurring within 48 hours of TIA or mild stroke onset. CTA, which uses contrast media to image the vasculature, can identify large artery disease, allowing physicians to determine risk. “A symptomatic intracranial or extracranial severe arterial stenosis or occlusion was predictive of recurrent stroke,” wrote the authors.

In the study, 491 patients with either TIA or minor stroke underwent CT/CTA within 24 hours of onset and most had subsequent MRI. Results showed there were 36 recurrent strokes, with a median time to the event of one day, and a positive CT/CTA scan was a predictor of recurrent stroke.

The authors concluded, “Adoption of CT/CTA into clinical practice for the assessment of patients with TIA and minor stroke identifies a high risk group suitable for aggressive acute stroke prevention treatment.”