Implantable cardiac monitors to detect atrial fibrillation after cryptogenic stroke

1.1 Reveal LINQ is recommended as an option to help to detect atrial fibrillation after cryptogenic stroke, including transient ischaemic attacks (TIA), only if:

1.2 Clinicians should consider if disabled people may need support from a carer to help set up the MyCareLink Patient Monitor, to ensure data from Reveal LINQ are transmitted for review.

1.3 There is not enough evidence to recommend the routine adoption of BioMonitor 2‑AF (or its successor device BIOMONITOR III) or Confirm Rx to help to detect atrial fibrillation after cryptogenic stroke. Further research is recommended to assess the diagnostic yield (a measure of how many people with atrial fibrillation are diagnosed) of these devices for atrial fibrillation when used in people who have had a cryptogenic stroke (see section 5.1).

Why the committee made these recommendations

After a cryptogenic stroke (a stroke with no identified cause), implantable cardiac monitors can be used for long-term monitoring to identify people with atrial fibrillation if this is thought to have been a cause of the stroke. Clinical trial evidence shows that using Reveal devices increases the detection of atrial fibrillation in people who have had a cryptogenic stroke (including TIA). If people then have an oral anticoagulant medicine, it is also likely to reduce the number of further strokes or TIAs compared with not using implantable cardiac monitors. How much this reduces strokes or TIAs is not known. There are other uncertainties about the impact of using the device in the NHS, such as how many times it produces a false positive alert (that is, incorrectly identifies atrial fibrillation).

However, even after considering these uncertainties, the committee concluded that Reveal LINQ is still likely to be a cost-effective use of NHS resources, if it's used after non-invasive ECG and no other cause for the stroke has been found. There is an unmet need for people who have had a cryptogenic stroke because there is no other option for long-term monitoring for suspected atrial fibrillation. Therefore Reveal LINQ is recommended for use in the NHS.

There's not enough evidence to show if using Confirm Rx or BioMonitor 2‑AF (or any previous versions of the technologies) increases atrial fibrillation detection compared with not using implantable cardiac monitors in people who have had a cryptogenic stroke. The evidence from Reveal devices cannot be used to make decisions about Confirm Rx or BioMonitor 2‑AF. This is because the devices use different algorithms to identify potential atrial fibrillation episodes and it's not certain that they will show similar performance in detecting atrial fibrillation when used in people who have had a cryptogenic stroke. Further research is needed to find out if these devices are clinically and cost effective. Therefore they are not recommended for routine adoption in the NHS.