Table 1.

Comparison of study designs and key findings of the AVERROES and ARISTOTLE trials [Connolly et al. 2011; and Granger et al. 2011].

Trial	AVERROES	ARISTOTLE
Design	RCT, double blind	Noninferiority RCT, double blind, double dummy, placebo controlled.
Patient population	Patients ‘unsuitable’ for VKA based on being unacceptable or prior failure	Patients with AFib and at least one other stroke risk factor
Treatment versus comparison	Apixaban versus aspirin	Apixaban versus warfarin
Number of subjects	5599	18,201
Primary outcome:	Stroke or systemic embolism: 1.6% per year in the apixaban group and 3.7% per year in the ASA group (p < 0.001)	Stroke or systemic embolism: 1.27% per year in the apixaban group, 1.60% per year in the warfarin group (p<0.001)
Secondary outcomes:	Major bleeding: 1.4% per year in the apixaban group, 1.2% per year in the ASA group (p = 0.57). All-cause mortality: 3.5% per year in the apixaban group, 4.4% per year in the ASA group (p = 0.07).	Major bleeding: 2.13% per year in the apixaban group, 3.09% per year in the warfarin group (p < 0.001). All-cause mortality: 3.52% per year in the apixaban group, 3.94% per year in the warfarin group (p = 0.047)

AFib, atrial fibrillation; ASA, aspirin at randomization; VKA, vitamin K antagonist; RCT, randomized-controlled trial.