Discussion
stroke
STROKE, PAF
We conducted the first trial in the United States to evaluate whether screening for AF at primary care encounters can increase detection in undiagnosed older individuals at least 65 years of age. This randomized controlled trial in over 30,000 individuals from a large primary care practice network demonstrated that screening for AF using handheld single-lead ECGs was feasible as part of routine care when embedded into vital signs assessments. Fully 91% of eligible patients underwent screening during the one-year study period. Single-lead ECG screening modestly increased same day 12-lead ECGs in intervention compared to control patients, driven mainly by more 12-lead ECGs in those with a “possible AF” result. PCPs in both intervention and control practices favored routine screening for AF. Intervention PCPs favored the single-lead ECG over pulse assessment even though they recognized that it generated many false-positive results.Opportunistic screening for AF with PCPs performing pulse assessment during visits has been shown to increase detection [Patients in our study favorably viewed screening with 91% undergoing at least one single-lead ECG over 1 year. Other studies have also elicited favorable patient views about screening for AF [The lack of a significant increase in AF detection among patients in the intervention practices may have been partly due to most PCPs in control practices reporting that they performed pulse assessment at all or most visits. For PCPs who do not routinely perform pulse assessment, single-lead ECGs may still be an efficient way to screen for AF in older patients.Regarding health care utilization, we found that single-lead ECG AF screening implemented within routine primary care resulted in a modest net increase in 12-lead ECG utilization. The increase in 12-lead ECG utilization observed in those with an abnormal screening result was partially offset by reduced utilization in those with a normal result. Future studies should assess other downstream cardiac testing as well as cardiology and emergency department visits that may be related to single-lead ECG AF screening.30-s single-lead ECG assessment primarily identifies individuals with persistent AF. Those with paroxysmal AF (PAF) may also be at increased stroke risk [This study has several limitations. We performed the study in a single academic primary care network, and results may not generalize to practices organized in a different way. Our high screening rate reflects workflow adaptation at the practice level and in-person training and refreshers by study staff for medical assistants. Though AF screening was offered at all visits during the study period, the optimal frequency of screening is uncertain. Intervention PCPs knew that single-lead ECGs would be reviewed by cardiologists who would notify them of any concerning findings. Though similar to what is done when obtaining a 12-lead ECG in our network, this level of study oversight may not be feasible as part of routine primary care. Lastly, the 30-s single-lead ECG is most likely to detect persistent AF, where there is little uncertainty regarding the net benefit of anticoagulation for patients with elevated predicted stroke risk. Our intervention study and survey were done before the COVID pandemic, and PCPs favoring office-based over outpatient screening for undiagnosed AF may have changed with increased experience with virtual visits.