According to Hans-Christoph Diener, M.D., professor and chairman, Department of Neurology and Stroke Center, University Hospital Essen in Essen, Germany, the investigational oral drug apixaban was found superior to aspirin to the degree researchers were advised to end the trial early.
Apixaban blocks factor Xa, a crucial step in blood clot formation. (Atrial fibrillation or AF patients are at increased risk of ischemic stroke because the heart beats irregularly and thus, clots form much more readily. As many as half of all AF patients with moderate or high stroke risk factors are not suitable for the most effective anti-clotting treatment, warfarin.)
Risk of major bleeds compared to aspirin were not shown to occur, as expected, with apixaban.
Randomized participants received between 2.5 and 5 milligrams of apixaban twice a day or between 81 mg and 324 mg of aspirin per day. After 1.1 years of follow up, researchers found 51 strokes or systemic embolism events in 2,808 patients taking apixaban compared to 113 strokes and systemic embolic events in the 2,791 patients taking aspirin.
Those rates made for a total of 1.6 percent risk of stroke for apixaban compared to 3.6 percent risk for aspirin.