Clinical Question

Does screening for atrial fibrillation (AF) in people 65 years and older in the primary care setting improve patient outcomes?

Bottom Line

The U.S. Preventive Services Task Force assigned a grade of I for insufficient evidence for screening for AF (a summary is available at https://www.aafp.org/pubs/afp/issues/2022/0600/od1.html). This study was a large, adequately powered trial and an important addition to the evidence base. It found no benefit in screening for AF. An increased rate of diagnosis in the oldest patients was found, but this is hypothesis-generating only and requires confirmation. The balance of benefits and harms of anticoagulants for patients 85 years and older is less favorable than for younger patients because of competing causes of mortality (i.e., dying of something else before having a stroke). (Level of Evidence = 1b−)

Synopsis

This study, sponsored by the manufacturers of the direct oral anticoagulant apixaban, randomized 16 primary care clinics to provide screening for AF using a single-lead handheld electrocardiograph or usual care. Comparable clinics were paired, and one clinic from each pair was randomly selected to be in the screening group to increase the comparability of the overall groups; the two groups were similar in demographics, vital signs, and comorbidities. The primary analysis was by intention to treat. The screening practices group included 15,393 people, and the usual care practices group comprised 15,322 people. Patients 65 years and older in the screening group were offered screening at each clinic visit; 72% underwent screening. After one year, there was no difference between groups in the primary outcome of newly diagnosed AF (1.72% screened, 1.59% unscreened; risk difference = 0.13%; 95% CI, –0.16% to 0.42%). Per-protocol and as-treated analyses came to the same conclusion. There was no difference between groups in the likelihood that a patient received a new prescription for an anticoagulant. The authors analyzed post hoc data and found that among patients 85 years and older, there was a significantly greater likelihood of being diagnosed with AF in the screened group (5.6% vs. 3.8%; risk difference = 1.8%; 95% CI, 0.18% to 3.3%).