News - Hypertension Week of Feb. 23, 2003/ Vol. 2 No. 08

Study: Baby Aspirin May Not Be Enough for Stroke Protection

People who take baby or coated aspirin to guard against strokes may not be getting the level of blood-thinning that they need, according to a preliminary study presented Feb. 14th at the American Stroke Association's international stroke conference.

Researchers at Chicago's Northwestern Memorial Hospital collected data on aspirin dose, type, demographic factors and homocysteine level on patients with cerebrovascular disease, including ischemic stroke, transient ischemic attacks (TIAs) and blockage of a cerebral artery. Antiplatelet effects of aspirin were measured using a machine that measures platelet function in response to aspirin.

The researchers found that 56 percent of 39 patients who took baby aspirin (81 mg) did not show an antiplatelet or blood-thinning effect. Of the 40 patients who took coated aspirin, 65 percent experienced no antiplatelet effect. Of the 87 patients who took an adult aspirin (325 mg), only 28 percent did not show an antiplatelet effect, compared to 25 percent who took an uncoated aspirin.

While research has established that aspirin reduces the risk of stroke in patients with cerebrovascular disease, study author Dr. Mark Alberts said the optimal dose and formulation still remains somewhat unclear.

Alberts, who directs the stroke program at Northwestern Memorial Hospital, said the long-term goal of the research is to determine if the type and strength of aspirin can be better tailored to maximize its effects as a clot-busting agent. He said routine testing of the antiplatelet effects of aspirin might be necessary.

"Certainly we're not advocating that anyone change their dose of aspirin or stop taking their aspirin," said Alberts. "They need to consult with their own physician and healthcare providers before they do anything."

However, Alberts said it is important for people to understand that aspirin does not work in everyone and that they should not just rely on aspirin alone for reducing the risk of stroke.

"Other things must be done," he said, noting that controlling blood pressure and diabetes, stopping smoking, eating right and exercising are all good ways for people to avoid strokes.

Other sources: Northwestern Memorial Hospital