Analysis shows safety of post-stroke therapy

Meta-analysis of nearly 340,000 post-stroke patients shows the superior safety of dipyridamole plus aspirin therapy.

The results of the analysis presented at the recent American Heart Association’s annual meeting, showed that the therapy was associated with the lowest bleeding risk compared with conventional dose and platelet therapies.

The meta-analysis included data from 50 clinical trials published from 1988 to 2002, with a total of 338,191 patients, to determine bleeding risks associated with antiplatelet agents.

"Bleeding risk from inhibiting platelets many significantly worsen the patient’s condition. In post-stroke patients, this is of particular concern because additional bleeding into the brain could have fatal consequences," said Dr. Victor Serebruany, director of the Sinai Thrombosis Center and assistant professor of medicine at the John Hopkins University in Baltimore, USA. He is lead researcher of the study.

"Although significant advancements in antiplatelet therapy have been made over the years, improving the life-saving clinical benefits in patients with vascular disease, more aggressive therapy, however, can also be associated with an increased risk of bleeding, which is a major concern among physicians," he said.

Bleeding rates associated with each antiplatelet agent were categorized by Serebruany with Doctors Alex Malinin and David Sane of John Hopkins University and Wake Forest University Baptist Medical Center according to minor bleeds, major bleeds, gastrointestinal (GI) bleeds, and hemorrhagic stroke.

In this analysis, low dose aspirin and dipyridamole therapy was associated with the lowest bleeding risk. No minor, GI or stroke bleeds were reported with dipyridamole therapy and major bleeds were reported in only 1.0 percent of patients.

Results were similar with low dose ASA: 1.8 percent minor bleeds, 1.1 percent GI bleeds, one percent major bleeds and 0.3 percent stroke bleeds.

In contrast, high rates of minor bleeding were reported with conventional dose at 6.5 percent; thienopryridines, 5.1 percent; GP IIb/IIa inhibitors-IV, 6.5 percent; and GP IIb/IIIa inhibitors-oral, 19.8 percent. Higher rates of GI bleeds were also reported with these agents.

"This meta-analysis clearly shows the benefits of low dose ASA in decreasing the risk of bleeding complications," said Dr. Barner, a member of the Boehringer Ingelheim board of managing directors.

"That’s a positive move toward patients’ safety in preventing secondary stroke. These findings should be considered when using combination therapy and/or anticoagulant therapy with conventional dose of ASA," Serebruany said.

In the European Stroke Prevention Study-2, the largest recurrent stroke prevention trial ever conducted, the combination of extended release dipyridamole and aspirin was twice as effective for secondary stroke prevention as either aspirin or dipyridamole alone, suggesting superior platelet inhibition for combination therapy.

The study examined the efficacy of aspirin/extended-release dipyridamole, aspirin alone, dipyridamole alone or placebo on the risk of recurrent stroke in 6,602 patients.