The NORwegian atrial fibrillation self-SCREENing (NORSCREEN) trial: rationale and design of a randomized controlled trial.

Aims: Atrial fibrillation (AF) is a common arrhythmia, and many cases of AF may be undiagnosed. Whether screening for AF and subsequent treatment if AF is detected can improve long-term outcome remains an unsettled question. The primary aim of the NORwegian atrial fibrillation self-SCREENing (NORSCREEN) trial is to assess whether self-screening for AF with continuous electrocardiogram (ECG) for 3-7 days in individuals aged 65 years or older with at least one additional risk factor for stroke, and initiation of guideline-recommended therapy in patients with detected AF, will reduce the occurrence of stroke.

Methods and results: This study is a nationwide open, siteless, randomized, controlled trial. Individuals ≥65 years of age are randomly identified from the National Population Register of Norway and are invited to take a digital inclusion/exclusion test. Individuals passing the inclusion/exclusion test are randomized to either the intervention group or the control group. A total of 35 000 participants will be enrolled. In the intervention group, self-screening is performed continuously over 3-7 days at home with a patch ECG device (ECG247) at inclusion and after 12-18 months. If AF is detected, guideline-recommended therapy will be initiated. Patients will be followed up for 5 years through national health registries. The primary outcome is time to a first stroke (ischaemic or haemorrhagic stroke). The first participant in the NORSCREEN trial was enrolled on 1 September 2023.

Conclusion: The results from the NORSCREEN trial will provide new insights regarding the efficacy of digital siteless self-screening for AF with respect to stroke prevention in individuals at an increased risk of stroke.

Trial registration: Clinical trials: NCT05914883.