Atrial Fibrillation Screening Using Smartphones Significantly Increases Detection Rate

Axel Bauer, MD

Screening for atrial fibrillation (AF) using digital technology in smartphones provides benefits in detection and treatment rates in older patients compared with routine screening, according to late-breaking findings from the European Society of Cardiology Congress 2022.

The eBRAVE-AF study met its primary endpoint, suggesting that digital screening more than doubled the detection rate of treatment-relevant AF in each trial phase.

“Screening using common smartphones significantly increased the detection rate of therapy-relevant atrial fibrillation,” said presenting author Professor Axel Bauer, MD, Innsbruck Medical University in a statement. “Importantly, app-based pre-screening was only one part of the programme, which also included electrocardiogram (ECG) validation and assessment of the findings by an independent physician.”

Despite being the most common heart rhythm disorder, AF often has no symptoms and may remain undiagnosed. With a five times greater risk of stroke in those affected compared to peers, patients may be unprotected as a result.

The potential of smart devices for large-scale AF screening has been observed, but the research primarily included younger adults, of whom screening has lower relevance and required the participants to own particular hardware. Thus, it remains unclear how older adults may deal with digital technologies and if screening results in initiation of oral anticoagulation.

In the eBRAVE-AF trial, smartphone screening was compared to usual screening for the ability to detect AF. The siteless, randomized study included policyholders of a Germany insurance company who were aged 50 to 90 years and were free of AF at baseline to digital screening or usual care.

From 67,488 invite policyholders, the trial enrolled 5,551 with a mean age of 65 years and 31% women. Each participant was randomly assigned to a six-month digital or convention AF screening strategy. The digital arm downloaded an app to their own smartphone in order to measure pulse wave irregularities using the built-in photoplethysmographic (PPG) sensor.

Participants were required to measure twice a day for 14 days and then twice a week, with reminders sent using push notifications. The conventional arm consisted of AF screening in real-world practice, including by symptoms and routine ECG screening.

Both groups collected information on newly detected AF via app-based questionnaires as well as telephone calls and insurance claims data. The primary efficacy endpoint was newly diagnosed AF within 6 months leading to initiation of oral anticoagulation by an independent physician.

The study included a total of 2,860 participants assigned to digital screening and 2,691 participants were assigned to conventional screening. Investigators observed the primary endpoint occurred in 38 participants (1.33%) in the digital arm and 17 (0.63%) in the conventional arm, with an odds ratio (OR) of 2.12 (95% confidence interval [CI}, 1.19 - 3.76; P = .010).

Then, all who did not meet the primary endpoint within the first six months were invited to partake in a second six-month study phase with crossover assignment to convention screening, respectively. Bauer and colleagues noted this gave all participants the opportunity to undergo digital screening and enabled validation of the primary results.

The second study phase crossed over a total of 4,752 (85.6%) of participants, wherein digital screening was once more superior to convention screening in detecting AF and initiating oral anticoagulation (33 of 2,387 versus 12 of 2,365 participants; OR, 2.95; 95% CI, 1.52 - 5.72; P = .001). Secondary analyses suggest findings on AF, PPG-detected AF, and abnormal PPG significantly predicted major adverse cardiac and cerebrovascular events (MACCE).

“We found that digital screening was well received by older participants, who tended to perform even more PPG measurements than younger participants in the study,” Bauer added. “Digitally detected atrial fibrillation as well as abnormal PPG measurements per se were of prognostic significance as they predicted MACCE.”

“eBRAVE-AF - Smartphone-based AF screening,” was presented at ESC 2022.