Alternative antiplatelet agents, alone or as adjunct, more effective than continuing aspirin monotherapy after new ischemic stroke
While the study may support the idea that alternative antiplatelet strategies are better than continued aspirin monotherapy in patients who have a stroke while on aspirin, with respect to stroke recurrence alone, switching to other antiplatelet agents was nominally but not statistically more effective than maintaining aspirin monotherapy.
In patients who had a new ischemic stroke while taking aspirin, changing to an alternative antiplatelet agent or adding another antiplatelet agent was more effective for preventing vascular events than continuing aspirin monotherapy, a South Korean study found.
Researchers used a stroke registry database from 14 South Korean hospitals to evaluate different subsequent antiplatelet strategies in patients who had a new ischemic stroke while taking aspirin for prevention. Adults who were taking aspirin and had an acute noncardioembolic stroke were divided into 3 groups: those who maintained aspirin monotherapy, those who switched from aspirin to nonaspirin antiplatelet drugs, and those who added a different antiplatelet drug to aspirin. The study's primary end point was a composite of ischemic and hemorrhagic stroke, myocardial infarction, and vascular death at 1 year. The study was published online Nov. 24 by Stroke.
Of 25,998 stroke patients who were treated from April 2008 through July 2013 and evaluated for the study, 1,172 patients were included, 212 (18.1%) who continued aspirin monotherapy, 246 (21.0%) who switched to another antiplatelet agent, and 714 (60.9%) who added another antiplatelet agent to aspirin. The mean age (±SD) was 69.7±10.9 years, and 58.7% were men. Over a mean follow-up (±SD) of 278±129 days, 86 patients experienced the composite outcomes. At 1 year, the cumulative event rate was 8.2%, and most of the primary outcome events (73.3%) happened in the 3 months post-stroke. Compared with the group who continued aspirin monotherapy, the other 2 groups had a reduction in the composite primary end point: a hazard ratio of 0.50 (95% CI, 0.27 to 0.92) in those who switched to a different antiplatelet agent (P=0.03) and a hazard ratio of 0.40 (95% CI, 0.24 to 0.66) in those who added a different antiplatelet agent to aspirin (P<0.001).
The authors said that their study supported the idea that alternative antiplatelet strategies are better than continued aspirin monotherapy in patients who have a stroke while on aspirin. “However, it should be noted that, although composite vascular event rates were reduced, with respect to stroke recurrence alone, switching to other antiplatelet agents was only nominally, not statistically, more effective than maintaining aspirin monotherapy,” they wrote. They also said that their study was registry-based in a single country, that adherence to and duration of antiplatelet therapy could not be determined, and that the combination of aspirin and extended-release dipyridamole was not commercially available in Korea at the time of the study, among other limitations. However, they concluded that switching to or adding another antiplatelet agent to aspirin may be associated with reduced vascular events after new ischemic stroke when compared with continuing aspirin monotherapy. The authors noted that their results should be interpreted with caution and confirmed in future randomized trials.