DOACs for Stroke Prevention in Device-Detected AF

Quick Takes

  • Two trials compared direct oral anticoagulants (DOACs) to either aspirin or placebo for patients with subclinical AF.
  • DOAC therapy was associated with a reduction in ischemic stroke and a composite of thrombotic complications.
  • DOAC therapy did not reduce mortality and was associated with an increased risk of major bleeding.

Study Questions:

Is oral anticoagulation effective and safe for patients with device-detected subclinical atrial fibrillation (AF)?


The authors performed a systematic review of randomized trials comparing oral anticoagulation with antiplatelet or not antithrombotic therapy in adults with device-detected AF recorded by a pacemaker, implantable cardioverter-defibrillator, cardiac resynchronization therapy device, or implanted cardiac monitor. The primary efficacy outcome was ischemic stroke with a secondary outcome as the composite of cardiovascular (CV) death, all-cause stroke, peripheral artery embolization, myocardial infarction, or pulmonary embolism. The primary safety outcome was major bleeding defined by the International Society on Thrombosis and Hemostasis criteria.


The authors identified two randomized trials inclusive of 6,548 patients (NOAH-AFNET 6 and ARTESiA) comparing either edoxaban or apixaban compared to aspirin or placebo. Included patients were at moderate to high risk of stroke (median CHA2DS2-VASc score 3.9-4) with a median duration of device-detected AF of 1.5-2.8 hours. Use of direct oral anticoagulation (DOAC) was associated with a reduction in the risk of ischemic stroke (relative risk [RR], 0.68; 95% confidence interval [CI], 0.50-0.92) and the composite of thrombotic outcomes (RR, 0.85; 95% CI, 0.73-0.99). There was no reduction in the risk of CV death (RR, 0.95; 95% CI, 0.76-1.17). Oral anticoagulant use was associated with an increased risk of major bleeding (RR, 1.62; 95% CI, 1.05-2.50).


The authors conclude that the NOAH-AFNET 6 and ARTESiA trials are consistent with each other—associated with a reduction in ischemic stroke and an increase in the risk of major bleeding.


Clinicians are increasingly facing the difficult task of determining if subclinical AF should receive the same stroke prevention treatment efforts as patients with clinical AF. Widespread use of implanted cardiac devices often detect runs of AF that are asymptomatic. These two randomized trials demonstrate that in a population of patients at moderate to high risk of stroke, use of DOACs is associated with a reduction in the subsequent risk of stroke as compared to aspirin or placebo when subclinical AF is detected. However, that benefit is offset by a notable 60% increased risk of major bleeding. Notably, use of anticoagulation was not associated with a reduction in CV death across the two trials. For clinicians trying to determine if oral anticoagulant should be prescribed for their patients with subclinical AF, longer durations (>2-4 hours) and higher baseline stroke risk (CHA2DS2-VASc score ≥4) may be populations best to target with this therapy, as long as the bleeding risk is not prohibitively high.

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Anticoagulation Management and Atrial Fibrillation, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: Anticoagulants, Atrial Fibrillation, Stroke

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