CardioExchange Archive

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 an annual rate of the primary endpoint — a composite of stroke or systemic embolism — of 3.6% per year in the aspirin group and 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 1.2% per year on aspirin and 1.4% per year on apixaban (HR 1.14, CI: 0.74–1.75, 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, Harald Arnesen, said AVERROES was a “landmark study that will affect guidelines,” and he predicted that aspirin use would diminish after apixaban becomes available.