Intracranial Stenosis Nearly Doubles Stroke Risk

Pam Harrison

March 15, 2013

VIENNA, Austria — The risk for recurrent stroke is almost twice as high in acute stroke survivors who have significant intracranial stenosis on early cerebral computed tomography (CT) and CT angiography, Danish researchers report.

"We found a very strong correlation between intracranial stenosis and risk factors for large artery disease and poor outcomes, not only for recurrent stroke, but also for myocardial infarction and death, despite the use of guideline-recommended secondary prevention measures," Hanne Christensen, MD, from the University of Copenhagen in Denmark, told Medscape Medical News.

The researchers found that 13% of patients with evidence of stenosis had a recurrent stroke, as did 8% of those with no intracranial stenosis. Cerebral scans were performed within 4.5 hours of presentation to the stroke unit.

The findings, presented here at the European Congress of Radiology 2013, showed that the combined risk for death and recurrent stroke was higher in those with stenosis than in those with patent intracranial arteries (22% vs 14%).

For the 652 stroke patients, mean follow-up was 701 days. The majority (n = 488) had acute stroke; the remainder (n = 164) had transient ischemic attack.

Patients were scanned using a 64-slice multidetector CT, and images were systematically reviewed by blinded neuroradiologists.

"We found that 15.5% of our patients had a 30% or greater stenosis, whereas 6.8% of them had a 50% or greater stenosis," Dr. Christensen reported.

The presence of intracranial stenosis was strongly associated with known cardiovascular risk factors, including high blood pressure and hypercholesterolemia.

Stenosis Linked to Other Risk Factors

After adjustment for all risk factors, the hazard ratio for recurrent vascular events was significantly higher in patients with any degree of intracranial stenosis. This was not the case for death.

Those with intracranial stenosis greater than 70% had the highest risk for a poor outcome, the researchers found.

"We know that aggressive medical treatment is likely to improve prognosis," Dr. Christensen said, "and we believe that doing routine CT angiography in acute stroke will help us identify patients at high risk for future events and for whom we may then prescribe more precise preventive therapy."

Péter Barsi, MD, chair of neuroradiology at the University of Pécs in Hungary, who was asked by Medscape Medical News to comment on the study, said that it is important to distinguish between patients who will benefit from aggressive medical therapy and those who will not be helped or who could be harmed by it.

"This is one of the very important steps because interventions are sometimes offered to patients who don't really benefit from them," Dr. Barsi said. "I believe international CT and CT angiography protocols should become more widespread, and eventually be used in most acute stroke centers," he added.

The researchers and Dr. Barsi have disclosed no relevant financial relationships.

European Congress of Radiology (ECR) 2013: Abstract B37. Presented March 8, 2013.