CSAF-AW study

Stroke is a leading cause of morbidity and mortality in the United Kingdom with more than 100,000 hospital admissions recorded in the UK per year. 25% of these are recurrent events, suggesting many patients remain high risk despite thorough investigation and medications. The fear of recurrence leads to significant anxiety in patients when no cause is found despite a thorough diagnostic workup, also known as Cryptogenic strokes (CS).

Atrial fibrillation (AF) is found in more than a third of stroke events and is a treatable cause. However- it comes and goes, sometimes silently, meaning it may not be picked up during a hospital admission.

In cryptogenic strokes- the longer we look the more AF we find. Studies that have used continuous heart rhythm monitors implanted under the skin have shown that AF actually can be found in up to a 33% of these patients. When long-term monitoring isn't performed - its only found in 2%.

This is where CSAF-AW comes in- can we replicate high AF detection rates WITHOUT the invasive implantation of a monitor under the skin? The Apple Watch allows high-frequency heart rhythm monitoring and has an ECG recording system in place.

The research hypothesis is:

"Can a prolonged, non-invasive heart rhythm monitoring strategy using the Apple Watch increase the AF detection rate in patients after a cryptogenic stroke."

We're recruiting 192 patients and randomising half to continue with standard care and half to receive additional Apple Watch heart rhythm monitoring to try and answer this question. Patients in the Apple Watch group will be able to send their recordings to a team of Cardiologists who will analyse them and be able to advise asap.

We're recruiting patients from 4 stroke centres in the London Stroke Network:

Whipps Cross University Hospital

Royal London Hospital

Newham General Hospital

National Hospital for Neurology & Neurosurgery.

This study has been approved by the Health Research Authority Ethics Board (West Midlands Solihull REC) and is sponsored by Barts Health NHS Trust. The devices have been kindly provided by Apple Inc and funding for research nurse support has been provided by Barts Charity.

If you're interested in finding out more, please email bartshealth.bartsaf@nhs.net