Klopidogrel w połączeniu z kwasem acetylosalicylowym u chorych z migotaniem przedsionków – badanie ACTIVE-A Based on: Effect of Clopidogrel Added to Aspirin In Patients with Atrial Fibrillation. N. Engl. J. Med. 2009 May 14; 360(20): 2066-78.

Abstract

Vitamin K antagonists reduce the risk of stroke in patients with atrial fibrillation, but in some patients their use is limited due to the side effects. The ACTIVE-A trial was performed to investigate the hypothesis whether the addition of clopidogrel to aspirin would be safe and effective therapeutic option in patients with this type of arrhythmia.

Methods: 7554 patients with atrial fibrillation and increased risk of stroke were assigned to receive clopidogrel or placebo in addition to aspirin instead of vitamin K antagonists. The primary outcome was the composite of stroke, myocardial infraction, non – central nervous system systemic embolism, or death from vascular reasons.

Results: After 3,6 years of follow – up, major vascular events had occurred in 832 patients receiving clopidogrel (6,8% per year) and 942 on placebo (7,6% per year) (relative risk with clopidogrel 0,89; 95% CI: 0,81–0,98; p=0,01). There had been a main difference in the number of stroke, which had appeared in 296 patients actively treated (2,4% per year) in contrast with 408 patients receiving placebo (3,3% per year) (relative risk 0,72; 95% CI: 0,62–0,83; p <0,001). Myocardial infarction occurred in 90 patients from clopidogrel group (0,7% per year) and in 115 from placebo group (0,9% per year) (relative risk 0,78; 95% CI: 0,59–1,03; p=0,08). Major bleeding complicated the therapy in 251 patients with two antipatelets drugs (2,0% per year) and in 162 receiving aspirin (1,3% per year) (relative risk 1,57; 95% CI: 1,29–1,92; p <0,001).

Conclusions: In patients with atrial fibrillation who are not able to receive vitamin K antagonists clopidogrel added to aspirin is effective in reducing the risk of major vascular events, including stroke. One should also consider the increase in the risk of major haemorrhage during such a therapy.