Risk-Based Screening for the Evaluation of Atrial Fibrillation Trial

Stroke is a leading cause of death and disability. A first diagnosis of atrial fibrillation may occur at the time of stroke (e.g. about 45% of patients with acute stroke). Undiagnosed atrial fibrillation is therefore a major care-gap in stroke prevention.

Against this backdrop, oral anticoagulant therapy is extremely effective at reducing the risk of ischemic stroke in atrial fibrillation, associated with a two-thirds risk reduction. Therefore, a major care gap in stroke prevention is the prevalence of undetected atrial fibrillation in the community. Traditional pulse screening in all patients > 65 years detects new atrial fibrillation in about 1% of people.

The CHA2DS2-VASc score was developed and validated to risk-stratify patients with atrial fibrillation into low, intermediate and high risk of stroke. The Investigators believe that the CHA2DS2-VASc score represents an opportunity to identify patients at high risk of atrial fibrillation, but also identifies this at highest risk of stroke, and therefore those that will derive greatest benefit from anticoagulant therapy.

The advent of external-worn event loop recorders (ELRs) present a more convenient and efficient method of detecting atrial fibrillation. Loop recorders have an in-built diagnostic algorithm that identifies atrial fibrillation, and initiates recordings before and after the event-trigger. This rhythm strip is then examined and confirmed by the trial cardiac technician. The investigators will examine if using external loop recorders in patients identified as high risk will improve the detection rate of paroxysmal atrial fibrillation.

The study is a randomised controlled cross-over multi-centered clinical trial in General Practice. Ethical approval has been sought from the Galway University Hospitals research ethics committee. The investigators have also engaged with Clinical Research Patient and Public Involvement.

The investigators primary research question is whether extended cardiac rhythm monitoring (with ELR for 1 week), compared to standard care, in patients pre-identified to be at high-risk of atrial fibrillation (defined by CHA2DS2-VASc score >2) increases the detection of new atrial fibrillation resulting in introduction of oral anticoagulant therapy, that is efficient, acceptable to patients and cost-effective.

All participating general practices will require the Socrates software package. The investigators will run analyses to identify patients with a CHA2DS2-VASc of 3 or greater. The investigators will exclude all patients with known atrial fibrillation, those in whom contraindications to oral anticoagulant therapy exist, and those who are deemed unsuitable for extended monitoring.

Inclusion criteria

• Signed a study specific Informed Consent Form
• 55 years of age or older
• Attending one of the participating General Practices in the R-BEAT Trial
• Attended at least one GP appointment within the past 12 months
• CHA2DS2-VASc Score >2

Exclusion criteria

• Contraindication to oral anticoagulant therapy

• History of intracerebral haemorrhage
• Prior intolerance or refusal of oral anticoagulant therapy

*(If intolerant or refused warfarin, may be included if considered suitable for non vitamin-K oral anticoagulant, NOAC)

• Gastrointestinal haemorrhage of unexplained or unmodifiable aetiology (i.e. risk of haemorrhage has not been reduced)
• Other major bleed that would exclude oral anticoagulant therapy
• Known Atrial fibrillation/flutter
• Currently prescribed oral anticoagulant therapy
• Unsuitable for anticoagulant therapy, in opinion of attending general practitioner
• Unsuitable for cardiac monitoring, in opinion of attending general practitioner
• Allergies to plasters or adhesives
• Has had cardiac monitoring for >48 hours within the last 12 months, has an implantable loop recorder, or scheduled to have cardiac monitoring/ILR.