Why is this research needed?

Having atrial fibrillation (AF), a type of irregular heart rhythm, is a risk factor for ischaemic stroke – both having a stroke in the first place and going on to have further strokes after the first one. Fortunately, if you have AF your risk of having a stroke can be reduced with treatments such as blood thinners.

For this reason, ischaemic stroke survivors in the UK are usually offered up to three days of heart monitoring after a stroke. However, having AF doesn’t necessarily mean that your heart is always beating irregularly. With a monitoring window of only three days, it can be easy to miss AF.

Prolonged cardiac monitoring (PCM) involves wearing a heart monitor for up to a month and gives a much better chance of detecting AF. Unfortunately, only about 1 in 20 stroke clinicians in the UK have access to PCM for their patients, and it can be hard to know who to prioritise for this longer testing.

One way this could be done is by looking at levels of NT-proBNP, a protein that the heart releases into the bloodstream when it’s under stress. From previous research, the OASIS team know that people who have AF tend to have high levels of NT-proBNP in their bloodstreams, but we don’t yet know what would happen in a real-world setting if we used NT-proBNP levels as a guide for deciding whether someone should receive standard heart monitoring or PCM.

What are the aims of this research?

Professor Jesse Dawson, Dr Alan Cameron, and the rest of the OASIS team are recruiting around 1200 people who’ve had an ischaemic stroke or a TIA (transient ischaemic attack, sometimes called a ‘mini-stroke’) from hospitals across Scotland. Because this is a study about figuring out who does and doesn’t have AF, people who already have a diagnosis of AF aren’t eligible to take part.

Participants are asked to provide blood samples so that the team can check NT-proBNP levels. They’re also asked to have three days of heart monitoring, the current standard in the UK.

The team expect that some people’s heart monitors will detect AF in those three days. Everyone else will be asked to carry on having PCM for a full month, because at the three-day mark it’s impossible to tell whether a negative result means that someone really doesn’t have AF, or if it’s just not been detected yet. 

Later, the team will assess whether there is a good match between someone’s NT-proBNP level and whether they turned out to have AF, and use this to calculate how many AF-related strokes could be avoided if the NHS used NT-proBNP levels to decide who gets longer heart monitoring and whether it would be cost-effective. They’ll also explore what stroke survivors and healthcare professionals think about PCM.

What is the benefit of this research?

Many stroke survivors say that one of their biggest fears is having another stroke, and untreated AF can make that more likely. If the OASIS team are correct that NT-proBNP could be used to identify more stroke survivors with AF, that also means more stroke survivors can access treatment that will reduce the risk of future strokes. In time, NT-proBNP testing could become a standard part of AF screening.

The OASIS team are hopeful that the simple blood test NT-proBNP, which is available in most NHS labs, can help target heart monitors to those who really benefit from them. This would increase detection of AF and save people who will definitely not have AF from the time and effort of extra tests. By increasing the number of people who are found to have AF and start blood thinners, this would help to reduce the risk of people having further strokes.

What PSP priorities does this research link to?

From 2019 to 2021, we worked with the James Lind Alliance on the Stroke Priority Setting Partnership (PSP). During the PSP process, we collaborated with people with lived experience of stroke and stroke professionals to find out what they thought were the top priorities in stroke research. From this, we identified the top ten priorities in two areas: prevention, diagnosis and short-term care, and rehabilitation and long-term care.

Now, when researchers apply to us for funding, we require that their work addresses at least one of these priorities, or a priority from the Childhood Neurological Disabilities PSP Top 10 as it relates to childhood stroke.

OASIS addresses the following priority from the Stroke PSP:

  • Prevention and acute care 5: Preventing secondary strokes

Meet the team

OASIS is led by Professor Jesse Dawson and Dr Alan Cameron.

Jesse is Professor of Stroke Medicine at the University of Glasgow and Consultant Physician at Queen Elizabeth University Hospital. We’ve previously funded multiple other projects led by Jesse, including the ELAN clinical trial which showed that blood thinners to reduce the risk of current stroke can be safely given to patients with AF much sooner after stroke than previously thought possible.

Jesse says, “We are hopeful that a simple blood test, available in most NHS labs, can help us target heart monitors to those who really benefit from them. This would increase detection of AF and save people who will definitely not have AF from the time and effort of extra tests.”

Alan is an Senior Clinical Lecturer at the University of Glasgow and Consultant in Stroke Medicine at NHS Greater Glasgow and Clyde. Alan also holds a Stroke Association Senior Clinical Lectureship for Medical Professionals and leads the Stroke Association-funded ASPIRE project.

The other members of the team include:

  • Jeremy Dearling, the team’s patient and public involvement (PPI) representative. Jeremy uses his personal experience of stroke to help guide the progress of the project, interpret findings, and share results with the stroke community, and works with Terry to support others affected by stroke to get involved with OASIS.
  • Terry Quinn, Professor in Cardiovascular Ageing at the University of Glasgow and Honorary Consultant in Stroke Medicine at NHS Greater Glasgow and Clyde. Terry works with Jeremy on ensuring that people affected by stroke and the general public are meaningfully involved in OASIS.
  • Alex McConnachie, Professor of Clinical Trial Biostatistics at the University of Glasgow. Alex leads on statistical analysis for the study.
  • Paul Walsh, Professor of Molecular Epidemiology at the University of Glasgow. Paul provides guidance on interpreting blood analysis results.
  • Deirdre Lane, Professor of Cardiovascular Health at the University of Liverpool. Together with Maggie, Deirdre works on understanding what makes it easier or harder for people affected by stroke to participate in OASIS.
  • Maggie Lawrence, Professor of Stroke Prevention at Glasgow Caledonian University. Together with Deirdre, Maggie leads on identifying factors that could help or hinder getting NT-proBNP screening used for AF screening across the NHS.
  • Dr Ross Campbell, Senior Clinical Lecturer at the University of Glasgow and Honorary Consultant Cardiologist at Queen Elizabeth University Hospital and Golden Jubilee National Hospital. Ross provides expert guidance on heart health and checks whether heart monitoring has correctly diagnosed AF.
  • Annelysse Jorgenson, a study manager, who oversees the day-to-day delivery of the project across the five sites where OASIS is taking place.
  • Research nurses from the Scottish Stroke Research Network who co-ordinate research activities such as contacting participants to check in with them during the heart monitoring period.