Reviewer: Dr. Mustafa Ferhat Keten

Name of the Study: Rationale and design of a digital trial using smartphones to detect subclinical atrial fibrillation in a population at risk: The eHealth-based bavarian alternative detection of Atrial Fibrillation (eBRAVE-AF) trial

Published Congress: ESC 2022

Link : https://www.escardio.org/The-ESC/Press-Office/Press-releases/Atrial-fibrillation-screening-using-smartphones-increases-detection-and-treatment

Background:

Atrial fibrillation is the most common heart rhythm disorder, affecting more than 40 million people worldwide.2 Those affected have a five times greater risk of stroke than their peers. Atrial fibrillation often has no symptoms and remains undiagnosed, leaving patients unprotected from stroke. Prior studies have shown the potential of smart devices for large-scale atrial fibrillation screening but they made no comparison with conventional screening, included primarily younger adults for whom screening has low relevance, and required participants to own certain hardware.

Objective:

It has been unclear to what extent older adults, who would benefit most from screening, could cope with digital technologies and whether screening results in initiation of oral anticoagulation. It was aimed to compare the conventional screening strategy and digital screening strategy in elderly patients.

Methods:

Patients over 50 years of age, with a policy of a major insurance company, with CHA2DS2-VASc ≥1 (women ≥2), without atrial fibrillation and not using oral anticoagulation were included in the study. Participants were randomly assigned to a six-month digital or conventional atrial fibrillation screening strategy. Those in the digital arm downloaded a certified app to their own smartphone that measures pulse wave irregularities using the phone's photoplethysmographic (PPG) sensor.6 To start a one-minute PPG measurement, participants placed their finger on the smartphone's camera. Participants were instructed to measure twice a day for 14 days, then twice a week – push notifications were used as reminders. In case of abnormal results, participants were posted a patch to record a 14-day ECG which they then returned by post. The researchers evaluated the ECG, sent the results to participants and asked them to consult their local physician, who made the treatment decision and was not involved in the study. The primary efficacy endpoint was newly diagnosed atrial fibrillation within six months leading to initiation of oral anticoagulation by an independent physician.

Results:

The primary endpoint occurred in 38 participants (1.33%) in the digital arm and 17 (0.63%) in the conventional arm, for an odds ratio (OR) of 2.12 (95% confidence interval [CI] 1.19–3.76? p=0.010). Those who did not reach the primary endpoint in the first six months were invited to take part in a second six-month study phase with crossover assignment to conventional or digital screening, respectively. This gave all participants the opportunity to undergo digital screening, increased the statistical power for secondary analyses, and enabled validation of the primary results. A total of 4,752 (85.6%) participants crossed over and entered the second study phase. Again, digital screening was superior to conventional screening in detecting atrial fibrillation that was then treated with oral anticoagulation (33 of 2,387 versus 12 of 2,365 participants? OR 2.95; 95% CI 1.52–5.72? p=0.001). In secondary analyses, atrial fibrillation, PPG-detected atrial fibrillation, and abnormal PPG findings significantly predicted major adverse cardiac and cerebrovascular events (MACCE)

Conclusion:

Screening and detecting AF in the target patient population with digital screening was found to be more sensitive than conventional methods.

Interpretations:

This study focused on a target population for atrial fibrillation screening rather than everyone else. Digital scanning appeared to do well with older participants, who tended to measure more PPG than younger participants in the study. Abnormal PPG measurements, as well as digitally detected atrial fibrillation, were found to have prognostic significance as they predicted MACCE.