The following are key points to remember from the US Preventive Services Task Force (USPSTF) 2018 Recommendation Statement on screening for atrial fibrillation (AF) with electrocardiography (ECG):

1. Conclusion: The USPSTF concludes that there is insufficient evidence to determine whether the benefits outweigh the harms of ECG screening in asymptomatic individuals aged ≥65 years for previously undiagnosed AF.
2. This conclusion is not a recommendation against ECG screening for AF. The recommendation is an “I statement,” i.e., there are insufficient data from clinical trials “to assess the balance and harms of the service.”
3. The simultaneously published Evidence Report by Jonas DE, et al., included 17 studies. Screening with ECG detected more new cases of AF than no screening, but in two studies, systematic screening with an ECG was not superior to opportunistic screening (pulse palpation-based diagnosis).
4. Scope of the Problem: AF is the most common arrhythmia world-wide. AF may increase the risk of stroke up to fivefold. About 20% of patients with a stroke associated with AF are unaware of AF prior to the stroke. Symptoms of AF may be subtle or unnoticeable. Stasis of blood due to a fibrillating left atrium and left atrial appendage may be the primary mechanism of clot formation. However, implantable device data from the TRENDS and ASSERT trials showed no relationship between the time of stroke and AF, suggesting that the role of AF and stroke is more complex than previously thought.
5. Potential Benefit of ECG Screening: Since it is established that anticoagulation reduces stroke incidence in patients with known AF, early detection of previously undiagnosed AF could lead to earlier stroke prevention via anticoagulation.
6. Potential Harm of ECG Screening: Anticoagulation can increase risk of major bleeding. A false-positive ECG could lead to unnecessary testing, procedures, treatment, as well as anxiety over a misdiagnosis.
7. ECG Techniques: AF can be diagnosed on a 12-lead ECG, ambulatory ECG monitor with 1-3 leads, or a single-lead telemetry strip. There has also been a rapid growth in smartphone ECG and pulse technologies and wearable devices. These newer ECG technologies are easy to use and readily available. Blood pressure cuff machines and pulse oximeters can also detect irregular rhythms. The REHEARSE-AF study showed the feasibility of using a smartphone ECG for screening.
8. Future Work: Randomized controlled trial data on asymptomatic patients comparing outcomes with and without screening ECGs are needed. The USPSTF acknowledged several ongoing trials (STROKESTOP, SCREEN-AF, IDEAL-MD, and D₂AF).
9. Clinical Considerations for the Present: Opportunistic screening (pulse palpation-based screening), studied in the SAFE study, is a reasonable means of screening with an adjunctive ECG, especially in high-risk individuals determined by the CHA₂DS₂-VASc score. Recent recommendations by the American Heart Association and European Society of Cardiology support opportunistic screening; 2018 Guidelines from the National Heart Foundation of Australia and Cardiac Society of Australia and New Zealand also support opportunistic screening.

Keywords: Anticoagulants, Anxiety, Arrhythmias, Cardiac, Atrial Appendage, Atrial Fibrillation, Blood Pressure, Diagnostic Errors, Electrocardiography, Heart Rate, Arrhythmias, Cardiac, Primary Prevention, Stroke, Telemetry, Vascular Diseases

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