Ending Aspirin Therapy May Triple Stroke Risk

When stroke survivors who are prescribed daily aspirin stop taking the drug, they may triple their risk of a having another stroke within days, research shows.

Strokes associated with stopping aspirin therapy "typically occur in eight to 10 days after stopping aspirin," says Patrik Michel, MD, a stroke researcher from the Lausanne University Hospital in Lausanne, Switzerland.

Michel presented his study at the American Stroke Association's International Stroke Conference 2005.

He says patients that are undergoing surgical procedures are routinely advised to stop taking aspirin because aspirin decreases the blood's ability to clot, which increases the bleeding risk during surgery. "But the bleeding risk in minor surgeries such as skin biopsies and dental surgery is really quite small. When we compare that small risk to the benefit of aspirin, it is possible that patients should be advised to continue aspirin," he says.

In his research, 309 people hospitalized with either a stroke or a "mini" stroke called a transient ischemic attack (TIA) were on daily aspirin therapy for prevention of stroke or heart attack.

He compared them with 309 people who had had a stroke or TIA more than six months previously and who had similar risk factors and were told to take daily aspirin.

The average age of patients in both groups was 71, and 62% were men.

Among the hospitalized patients, 13 people had stopped aspirin therapy in the month before their stroke. Four patients in the comparison group had stopped taking aspirin.

The study showed that stopping aspirin therapy was associated with a more than threefold risk of stroke.

"This is the first controlled, retrospective study to investigate the potential risk of suffering ... stroke shortly after discontinuing aspirin," says Michel.

The results confirm and extend previous observations in stroke survivors who stopped taking aspirin.