The AVERROES (Apixaban Versus Acetylsalicylic acid (ASA) to Prevent Strokes) trial randomized 5600 AF patients who were unable to take warfarin to receive either aspirin or apixaban, a Factor Xa inhibitor. (Another trial still underway, ARISTOTLE, is a direct comparison of warfarin and apixaban in AF.) AVERROES was stopped early after the Data Monitoring Committee found clear evidence of clinically important benefit and an acceptable safety profile.
Stuart Connolly reported a reduction in the primary endpoint of the study, a composite of stroke or systemic embolism, from 3.6% per year in the aspirin group to 1.7% per year in the apixaban group (HR 0.46, CI 0.33-0.64, p<0.001). The rate of major bleeding was 1.4% per year on apixaban and 1.2% per year on aspirin (HR 1.14, CI0.74–1.75, p=0.56). Hemorrhage stroke occurred at a rate of 0.2% per year in both treatment groups.
Connolly calculated that for every 1000 patients treated with apixaban for one year instead of aspirin 18 strokes, 10 deaths, and 31 CV hospitalizations could be prevented, at a cost of 2 major bleeds.
Commenting on the results in an ESC press release, Connolly said: “The results of AVERROES are truly impressive. The reduction in stroke and systemic embolism is very important and the increased risk of haemorrhage is small. It appears that apixaban will be an excellent treatment for the many patients with atrial fibrillation who are unsuitable for warfarin. These findings will reduce the burden of stroke in society.”
The designated discussant at the Hot Line presentation, H. Arnesen, said AVERROES was a “landmark study that will affect guidelines,” and he predicted that aspirin use would diminish after apixaban becomes available.
Here is the ESC press release:
AVERROES trial terminated early: apixaban associated with “important” relative risk reduction for stroke and systemic embolism in AF