The Atrial Fibrillation Clopidogrel Trial with Irbesartan for Prevention of Vascular
Events A (2009)


Stroke prevention in patients with AF

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To evaluate, if addition of clopidogrel to ASA would reduce the risk of vascular events in patients with AF

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Trial design

Randomized, double-blind placebo-controlled study
Active treatment: clopidogrel 75 mg plus ASA 75–100 mg once daily
Control treatment: matching placebo plus ASA 75–100 mg once daily

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Primary efficacy endpoint: composite of stroke, myocardial infarction,non-CNS systemic embolism or death from vascular causes
Secondary efficacy endpoints: stroke, all individual components of theprimary outcome; primary outcome and major hemorrhage
Primary safety endpoint: major bleeding
Secondary safety endpoints: minor bleeding, any bleeding

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Trial participants

7554 patients (mean age 71 years) with AF who had an increased risk of stroke and for whom vitamin K-antagonist therapy was contraindicated

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Efficacy outcome: After a median follow-up of 3.6 years, major vascularevents had occurred in 832 of 3772 patients receiving clopidogrel (6.8% peryear) and in 924 of 3782 patients receiving placebo (7.6% per year). The differencewas primarily due to a reduction in the rate of stroke with clopidogrel. Stroke occurred in 296 patients receiving clopidogrel (2.4% per year)and 408 patients receiving placebo (3.3% per year)
Safety outcome: Major bleeding occurred in 251 patients receiving clopidogrel(2.0% per year) and in 162 patients receiving placebo (1.3% per year)

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Efficacy: The addition of clopidogrel to ASA reduced the risk of major vascular events. This reduction was primarily due to a significant reduction in the risk of stroke
Safety: The patients treated with clopidogrel plus ASA had a significant increase in the risk of major and minor hemorrhage. With the combination of major vascular events (the primary outcome) and major hemorrhage, there was no significant difference between the overall event rate with ASA plus clopidogrel and the rate with ASA alone (968 vs. 996 events; p=0.54)

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Connolly SJ, Pogue J, Hart RG, Hohnloser SH, Pfeffer MA, Chrolavicious S, Yusuf S for the ACTIVE Investigators. Effect of clopidogrel added to aspirin in patients with atrial fibrillation. N Engl J Med 2009;360:2066-2078

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Corresponding author

Stuart J. Connolly, MD, Population Health Research Institute, McMaster University, 237 Barton Street East, Hamilton, ON L8L 2X2, Canada, e-mail:

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