Aspirin safer than warfarin for treating blocked arteries in the brain.

Aspirin is just as effective as warfarin for treating intracranial stenosis, and as a simpler, low cost drug, should be the drug of choice for treating atherosclerosis to prevent strokes, according to a new study.

The double-blind, randomised clinical trial, conducted at 59 medical centres across the United States, compared warfarin to a daily dose of 1300 mg of aspirin in over 500 patients who had experienced a trans-ischaemic attack or nondisabling stroke.

It found, for the first time, that aspirin works as well as warfarin with fewer side effects, leading researchers to suggest aspirin should be given preference by prescribers over the more expensive warfarin which requires more complicated and more expensive monitoring.

However the results were only relevant to people with intracranial stenosis, according to researchers, who cautioned people receiving warfarin for other conditions (such as an irregular heart rhythm or clots in the legs or lung) should not stop taking the drug.

Since the dose of aspirin used in the study was much higher than typical daily doses, there was some concern of an increase in the risk of gastrointestinal bleeding, but the investigators said it was the only amount for which earlier studies had provided good preliminary data

Even with treatment, the rates of ischemic stroke in this clinical trial were substantially higher than in stroke prevention trials that have evaluated aspirin and warfarin in patients with other causes of stroke. This underscored that patients with intracranial stenosis were at particularly high risk for stroke and that better therapies were needed, the investigators said.

--National Institute of Neurological Disorders and Stroke (NINDS)

Reference

Chimowitz, M.I. et al. Comparison of warfarin and aspirin for symptomatic intracranial arterial stenosis, New England Journal of Medicine, 2005, 352:12, pp. 1305-1316.