Importance: Atrial fibrillation is the most common type of cardiac arrhythmia (irregular heartbeat), and its prevalence increases with age, affecting about 3% of men and 2% of women aged 65 to 69 years and about 10% of adults 85 years and older. Atrial fibrillation is a major risk factor for ischemic stroke, increasing risk of stroke by as much as 5-fold. Approximately 20% of patients who have a stroke associated with atrial fibrillation are first diagnosed with atrial fibrillation at the time of stroke or shortly thereafter.

Objective: To issue a new US Preventive Services Task Force (USPSTF) recommendation on screening for atrial fibrillation with electrocardiography (ECG).

Evidence review: The USPSTF reviewed the evidence on the benefits and harms of screening for atrial fibrillation with ECG in adults 65 years and older, the effectiveness of screening with ECG for detecting previously undiagnosed atrial fibrillation compared with usual care, and the benefits and harms of anticoagulant or antiplatelet therapy for the treatment of screen-detected atrial fibrillation in older adults.

Findings: Most older adults with previously undiagnosed atrial fibrillation have a stroke risk above the threshold for anticoagulant therapy and would be eligible for treatment. Anticoagulant therapy is effective for stroke prevention in symptomatic persons with atrial fibrillation and high stroke risk. However, the USPSTF found inadequate evidence to determine whether screening with ECG and subsequent treatment in asymptomatic adults is more effective than usual care. At the same time, the harms of diagnostic follow-up and treatment prompted by abnormal ECG results are well established and include misdiagnosis and invasive testing. Given these uncertainties, it is not possible to determine the net benefit of screening with ECG.

Conclusions and recommendation: The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for atrial fibrillation with ECG. (I statement).