Atrial fibrillation screening with a smartphone app improves detection of the condition compared to usual symptom-based care
Detection of atrial fibrillation detection using a smartphone-based screening app more than doubles the rate of detection compared to usual care according to the results of a randomised trial by researchers based in Munich, Germany.
Atrial fibrillation (AF) is the most common cardiac arrhythmia and in 2019, was estimated to have a global burden of 59.7 million. The condition is diagnosed with an electrocardiogram trace showing AF and although most patients will experience symptoms such as chest pain, palpitations, shortness of breath, and fatigue, others have no symptoms, a condition referred to as asymptomatic or “silent” AF. Patients with AF are at an increased risk of stroke and one meta-analysis found that AF might be newly detected in nearly a quarter of patients with stroke or transient ischaemic attack, highlighting the need for early detection. Although smart device-based photoplethysmography technology could be a feasible approach for AF screening, whether such methods can increase detection more than usual, symptom-based care is uncertain.
For the current study, the German team therefore undertook an open-label, randomised trial to compare digital screening (using the smartphone app) or usual care. Eligible patients were free of AF at baseline and if there were any abnormalities detected via the app (based on pulse irregularities), these were verified using external ECG loop recorders. The study was conducted over a 6-month period and the primary efficacy endpoint was the first diagnosis of treatment-relevant AF and which led to the initiation of oral anticoagulant therapy. The secondary endpoints were newly diagnosed AF, stroke and newly prescribed oral anticoagulants. After the first 6 months, participants crossed over for a second phase of the study with reverse assignment.
Atrial fibrillation diagnoses
A total of 5,551 participants with a mean age of 65 years (31% female) were randomly assigned to digital monitoring (2,860) or usual care. Among the whole cohort, 15% had coronary heart disease and 6% a history of stroke.
Within the first 6 months, the primary endpoint was reached by 1.33% of those in the smartphone group compared to 0.63% in the usual care arm (odds ratio, OR = 2.12, 95% CI 1.19 – 3.76, p = 0.010).
A total of 4,752 individuals for whom the primary endpoint was not reached, crossed over for a second 6-month period. As with the first phase, the proportion achieving the primary endpoint was 1.38% vs 0.51% (OR = 2.75, 95% CI 1.42 – 5.34, p = 0.003).
There were also significant differences for the secondary endpoints of newly diagnosed AF (1.68% vs 0.89%, p = 0.011), newly prescribed anticoagulants (1.71% vs 0.85%, p = 0.006) but not for stroke (p = 0.95).
The authors concluded that smartphone-based screening increases the detection of AF compared with routine-symptom-based screening and suggested that future studies should focus on whether digital screening for AF leads to better treatment outcomes.
Rizas KD et al. Smartphone-based screening for atrial fibrillation: a pragmatic randomized clinical trial Nat Med 2022