TAM (Treatments and Medicines) NHS Highland
- AF: Atrial fibrillation
- DDAF: Device-detected atrial fibrillation
- DOAC: Direct oral anticoagulants
- ECG: Echocardiogram
- TIA: Trans ischaemic attack
Management of device-detected atrial fibrillation (Guidelines)
Warning
Audience
- All NHS Highland
- Primary and Secondary Care
- Adults only
Device-detected atrial fibrillation (DDAF) lasting more than 6 minutes occurs in 20% of patients with implanted pacemakers, defibrillators or long-term cardiac loop recorders. DDAF may be associated with an increased risk of stroke.
The risk of stroke in patients with DDAF is much lower (1% per year) than in patients who present with symptomatic ECG-documented AF, because DDAF usually occurs for much shorter durations and there is a lower overall AF burden.
Meta-analysis of two large trials (NOAH-AFNET 6 and ARTESiA) conducted in patients with DDAF episodes lasting > 6 mins and additional risk factors for stroke (mean age 77, mean CHADS-VASc 4) found that direct oral anticoagulants (DOACs):
- Reduced the relative risk of stroke by 30%, but increased the relative risk of major bleeding by 60%.
- Reduced the absolute risk of ischaemic stroke by 0.3% per year (3 fewer ischaemic strokes per thousand patient-years), but increased the absolute risk of major bleeding by 0.7% per year (7 more major bleeds per 1000 patient-years).
- A reduction in the risk of stroke and a smaller increase in major bleeding was observed only in the subgroup of patients with prior vascular disease, who already had an indication for antithrombotic therapy.
If DDAF > 6 mins occurs in a patient WITHOUT documented vascular disease (e.g. prior stroke/TIA, coronary or peripheral artery disease), it is NOT recommended to offer a DOAC.
This is because their < 1% annual risk of stroke does not justify the increased risk of major bleeding. If DDAF episodes are lasting > 24 hours, an individual risk assessment is advised (e.g. CHADSVA score), although weak evidence for a DOAC has not identified a difference compared to DDAF episodes lasting < 24 hours.
If DDAF > 6 mins occurs in a patient who is already prescribed an antiplatelet drug for documented vascular disease, such as aspirin or clopidogrel: a switch from their antiplatelet drug to a DOAC will offer a 1% lower annual risk of stroke, balanced with a 0.6% higher annual risk of major bleeding.
Our recommendations for DDAF are as follows:
| DDAF episode category | Risk of stroke |
Recommendations |
|
Less than 6 mins |
Not elevated |
Continued device monitoring |
|
More than 6 mins in patients without vascular disease |
< 1% per year |
Continued device monitoring and clinical monitoring for vascular disease |
|
More than 6 mins in patients with vascular disease |
2% per year |
Switch antiplatelet to apixaban. if no contraindications |
| More than 24 hours | > 1% per year |
Consider apixaban based on risk assessment (e.g. CHADSVA score) |
This guidance does NOT take into account important factors such as patient preferences or comorbidities.
- A DOAC is unsuitable for patients with a contraindication, e.g. due to high bleeding risk or frailty.
- The final decision whether to switch antiplatelet therapy to a DOAC in patients with vascular disease and DDAF should be individualised and shared between the physician/GP and the patient.
- The dose of apixaban for DDAF is the same as for ECG-documented AF.
DDAF guidance is indicated only for patients with implanted cardiac devices (pacemaker, defibrillator or loop recorder) that provide continuous ECG monitoring and high diagnostic accuracy. There are prospective randomised trials to indicate their risk and management.
If personal ECG devices suggest an arrhythmia (e.g. Apple watch, KardiaMobile or similar handheld ECG) the patient can be referred to the cardiologist via clinical dialogue with a copy of the ECG trace, if it would change their medical management.
Devices that analyse pulse waveform (photoplethysmography) without ECG capability cannot be used to diagnose arrhythmias. An ECG-based method must be used to confirm the diagnosis.
Please use clinical dialogue for any specific patient queries and a cardiologist can advise you further.