AUGUSTUS trial - Antithrombotic Therapy after Acute Coronary Syndrome (ACS) or PCI (percutaneous intervention) in Atrial Fibrillation (AF)
With respect to antithrombotic therapy for patients with atrial fibrillation who have an acute coronary syndrome or have undergone percutaneous coronary intervention (PCI) :
- oral anticoagulation is indicated to prevent stroke and systemic embolism in patients with atrial fibrillation but has not been shown to prevent stent thrombosis and is generally not indicated for secondary prevention after acute coronary syndrome
- dual antiplatelet therapy is proven to reduce the incidence of recurrent ischemic events and stent thrombosis but is less effective in reducing the incidence of cardioembolic stroke associated with atrial fibrillation
- the combination of antithrombotic agents, particularly triple therapy with oral anticoagulation and dual antiplatelet therapy, increases the risk of bleeding
Lopes et al investigated the use of antithrombotic therapy after acute coronary syndrome or PCI in atrial fibrillation (1)
- an international trial with a two-by-two factorial design
- randomly assigned patients with atrial fibrillation who had an acute coronary syndrome or had undergone PCI and were planning to take a P2Y12 inhibitor to receive apixaban or a vitamin K antagonist and to receive aspirin or matching placebo for 6 months
- primary outcome was major or clinically relevant nonmajor bleeding. Secondary outcomes included death or hospitalization and a composite of ischemic events
- study results:
- included 4614 patients from 33 countries
- were no significant interactions between the two randomization factors on the primary or secondary outcomes
- major or clinically relevant nonmajor bleeding was noted in 10.5% of the patients receiving apixaban, as compared with 14.7% of those receiving a vitamin K antagonist (hazard ratio, 0.69; 95% confidence interval [CI], 0.58 to 0.81; P<0.001 for both noninferiority and superiority), and in 16.1% of the patients receiving aspirin, as compared with 9.0% of those receiving placebo (hazard ratio, 1.89; 95% CI, 1.59 to 2.24; P<0.001)
- patients in the apixaban group had a lower incidence of death or hospitalization than those in the vitamin K antagonist group (23.5% vs. 27.4%; hazard ratio, 0.83; 95% CI, 0.74 to 0.93; P=0.002) and a similar incidence of ischemic events
- patients in the aspirin group had an incidence of death or hospitalization and of ischemic events that was similar to that in the placebo group
- conclusions:
- patients with atrial fibrillation and a recent acute coronary syndrome or PCI treated with a P2Y12 inhibitor, an antithrombotic regimen that included apixaban, without aspirin, resulted in less bleeding and fewer hospitalizations without significant differences in the incidence of ischemic events than regimens that included a vitamin K antagonist, aspirin, or both
In a post-hoc analysis of the Augustus trial (2):
- safety and efficacy of apixaban compared with vitamin K antagonists was consistent with the AUGUSTUS findings, irrespective of prior stroke/transient ischemic attack (TIA)/ thromboembolism (TE)
- aspirin increased major or clinically relevant nonmajor (CRNM) bleeding, particularly in patients without prior stroke/TIA/TE
- aspirin may have some benefit in patients with prior stroke, our findings support the use of apixaban and a P2Y12 inhibitor without aspirin for the majority of patients with AF and ACS and/or PCI, regardless of prior stroke/TIA/TE status
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