Screening for Atrial Fibrillation Using Economical and Accurate Technology (From the SAFETY Study)

The prevalence of atrial fibrillation (AF) is estimated at more than 3% in the adult population and there has been increased interest in screening for AF. In the SAFETY trial we chose to evaluate if inexpensive, wearable, consumer electrocardiography (ECG) sensing devices (Polar-H7 [PH7] and Firstbeat Bodyguard 2 [BG2]), could be used to detect AF accurately. We undertook a case-control study of 418 participants aged >65 (82 with AF and/or flutter at the study visit and 336 without) attending 3 general practice surgeries in Hampshire, UK for a single screening visit. The PH7 and BG2 devices were tested alongside 2 established AF detection devices (AliveCor and WatchBP) in random order and the diagnosis of AF was confirmed by 12-Lead ECG interpreted by a panel of cardiologists. The sensitivity (95% confidence interval [CI] range), specificity (95% CI range), and overall accuracy (95% CI range) of the 4 devices were: AliveCor: 87.8% (78.7% to 94.0%), 98.8% (97.0% to 99.7%), 96.7% (94.4% to 98.2%); WatchBP: 96.3% (89.7% to 99.2%), 93.5% (90.3% to 95.9%), 94.0% (91.3% to 96.1%): PH7: 96.3% (89.7% to 99.2%), 98.2% (96.2% to 99.3%), 97.9% (96.0% to 99.0%). BG2: 96.3% (89.7% to 99.2%), 98.5% (96.6% to 99.5%), 98.1% (96.3% to 99.2%). The PH7 and BG2 devices were highly reliable (the devices acquired sufficient data and obtained a diagnostic result in all but 1 participant on the first attempt). In conclusion, inexpensive, consumer heart rate monitoring devices (PH7 and BG2) can be used to detect AF accurately with sensitivity and specificity >95%. The consumer devices performed as well or better than WatchBP and AliveCor and have the capability to store or transmit ECG data which could be used to confirm AF.