DOACs for Stroke Prevention in Patients With Device-Detected AF
- In a meta-analysis of two randomized clinical trials, DOAC therapy reduced the risk of ischemic stroke in patients with device-detected subclinical AF.
- DOAC therapy did not reduce the risk of all-cause or CV death in the device-detected AF population.
- Major bleeding risk was increased with DOAC therapy as compared to aspirin or no antithrombotic therapy in patients with device-detected AF.
Is oral anticoagulation effective and safe in patients with device-detected subclinical atrial fibrillation (AF)?
The authors performed a systematic review and meta-analysis of randomized trials comparing oral anticoagulation to antiplatelet or no antithrombotic therapy in adults with device-detected AF. The primary outcome for efficacy was ischemic stroke. The key secondary outcome was a composite of cardiovascular (CV) death, all-cause stroke, peripheral artery embolization, and CV death. The primary safety endpoint was International Society on Thrombosis and Hemostasis (ISTH)-defined major bleeding.
The authors identified two randomized trials, the NOAH-AFNET 6 study of 2,536 patients with edoxaban or aspirin/placebo, and the ARTESiA study of 4,012 patients randomized to apixaban or aspirin. Meta-analysis found a reduction in ischemic stroke risk (relative risk [RR], 0.68; 95% confidence interval [CI], 0.50-0.92). There was also a reduction in the key secondary efficacy composite outcome (RR, 0.85; 95% CI, 0.73-1.00). There was no reduction in CV death or all-cause mortality. Oral anticoagulant use was associated with an increase in major bleeding (RR, 1.62; 95% CI, 1.05-2.5).
The authors conclude that direct oral anticoagulant (DOAC) use is associated with a lower risk of stroke and composite CV outcomes with an increase in major bleeding as compared to aspirin or placebo therapy in patients with device-detected subclinical AF.
With increasing prevalence of implanted cardiac devices (e.g., defibrillators, implanted cardiac event monitors), clinicians have struggled to know if anticoagulation therapy was warranted in patients with subclinically detected AF. Two randomized trials (NOAH-AFNET 6 and ARTESiA) have compared DOACs to aspirin or placebo therapy. This meta-analysis provides insights from a broader population with greater power to detect differences in efficacy and/or harm. The key findings are that anticoagulation therapy reduced ischemic stroke risk but increased the risk of major bleeding. Notably, there was no reduction in all-cause or CV death with anticoagulation therapy. It is also notable that the overall rate of stroke was lower than anticipated in both trials, suggesting that this may not be a particularly high-risk group (average duration of AF was 1.5-2.8 hours). As such, most patients with device-detected subclinical AF should not be treated with anticoagulation therapy. However, patients at higher baseline stroke risk, those with longer duration of AF, and those with symptomatic AF may benefit from anticoagulation therapy.
Keywords: Anticoagulants, Atrial Fibrillation, Stroke
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