Drug May Aid Aspirin After Ministroke

May 18, 2006 -- Researchers have spotted a drug combination that may help survivors of ministrokes and minor strokes.

The drug combination is aspirin and the antiplatelet drug dipyridamole. Dipyridamole is found in the drugs Aggrenox (which also contains aspirin) and Persantine.

A study in The Lancet shows that among people who had already had a transient ischemic attack (TIA, or “ministroke”) or a minor stroke, those who took aspirin and dipyridamole were less likely to suffer a nonfatal stroke or heart attack, have major bleeding complications, or die of vascular problems (problems related to their circulatory system) over 3.5 years.

The researchers included Ale Algra, MD, PhD, of the University Medical Centre Utrecht in the Netherlands.

About the Study

The study was the European/Australasian Stroke Prevention in Reversible Ischaemia Trial (ESPRIT). It included more than 2,700 patients from 79 hospitals in 14 countries.

The patients were 63 years old, on average. About two-thirds were men. None had had recent heart attacks, limited life expectancy, or medical reasons why they couldn’t take aspirin or dipyridamole.

The researchers randomly assigned patients to one of two drug plans:

• Aspirin alone
• Aspirin plus dipyridamole (preferably dipyridamole’s extended-release version)

Daily aspirin doses ranged from 30 milligrams to 325 milligrams.

Patients started on those plans within six months of their ministroke or minor stroke. They were followed for 3.5 years, on average.

Risk Reduction

Algra and colleagues bundled together four events -- death from vascular causes, nonfatal heart attack, nonfatal stroke, and major bleeding complications.

During the study, 173 patients taking aspirin and dipyridamole experienced at least one of those four events, compared with 216 who only took aspirin.

Those four events -- taken together -- were about 20% less likely in the patients who took aspirin and dipyridamole compared with those who only took aspirin. The results translate into an annual drop of 1% of those four events during the follow-up period.

Then the researchers added in results from other recent studies on the topic. They came up with a similar figure -- an 18% less likelihood of those same four events with aspirin plus dipyridamole compared to aspirin alone.

Side Effects, Limits

In the aspirin-plus-dipyridamole group, 470 patients stopped taking their drugs, compared to 184 assigned to aspirin alone.

Headaches, a possible side effect of dipyridamole, were the main reason for the dropouts in the drug combination group, the study shows.

The study was an “open” trial, meaning that the treatments weren’t concealed. “No large clinical trial is perfect and ESPRIT is no exception,” states a journal editorial.

However, the ESPRIT trial echoes the findings of two other trials, which is “a major strength,” writes editorialist Bo Norrving, MD, PhD, of the neurology department at University Hospital in Lund, Sweden.

“With today’s report dual dipyridamole and aspirin therapy joins the podium of well-established interventions to be applied in routine clinical practice in secondary stroke prevention,” Norrving writes. “However, further improvements are still needed and currently under study,” he adds.