Completed Heart, Stroke & Blood Psychology & Behaviour

Impact of clinically silent atrial fibrillation on cerebrovascular disease and cognitive decline in the UK Biobank Imaging Cohort

Funder BHF Charity-funded
Recipient organisation University of Oxford
Funding £2.5M
Period Jul 2019 — Jun 2024

In plain English

AI plain-English summary

A quarter of a million people in the UK carry a hidden heart condition—silent atrial fibrillation—that may be quietly damaging their brains without ever causing noticeable symptoms. This study will strap portable ECG monitors to 20,000 volunteers over 60 from the UK Biobank, tracking their heart rhythms for weeks to catch fleeting, symptomless episodes that standard check-ups miss. The problem is that doctors have long assumed atrial fibrillation causes strokes by throwing blood clots directly from the heart. But silent AF episodes don’t neatly line up with stroke timing, suggesting the link is more complex. It remains unknown whether these hidden arrhythmias slowly chip away at brain health, accelerating cognitive decline and dementia in the general population—not just in high-risk hospital patients. If this research succeeds, it could reshape how GPs screen for stroke risk. Instead of relying on a single pulse check, doctors might use longer monitoring periods in older adults, combined with genetic and blood markers, to catch silent AF before it causes irreversible brain damage. The findings could also refine the UK’s stroke prevention guidelines, potentially sparing thousands from preventable dementia and hospitalisation.

View original technical description
Silent paroxysmal atrial fibrillation (SCAF) can be detected by prolonged ECG monitoring in a significant proportion of individuals in sinus rhythm who have no previous history of AF. In specific patient groups, SCAF has been associated with a higher risk of stroke, although no proximate temporal relationship between SCAF episodes and stroke has been demonstrated, challenging the conventional view that the excess stroke risk in patients with AF is a direct consequence of the arrhythmia. It is unclear whether SCAF is associated with increased risks of cerebrovascular tromboembolism leading to cognitive decline in the general population. By performing long-term ECG monitoring in 20,000 individuals older than 60 years enrolled in the UK Biobank Imaging Cohort, we propose to assess the impact of SCAF on brain MRI and cognitive function (in the short-term) and on the incidence of clinical AF, stroke, myocardial infarction, hospitalization, dementia, and death (in the medium/long-term). This study will also allow a comprehensive evaluation of the relevance of biochemical, genetic, anthropometric and behavioral factors to SCAF and clinical paroxysmal and non-paroxysmal AF in the UK population, and provide the opportunity to test their value (in conjunction with brain, heart and carotid imaging) in refining stroke risk stratification.

View the original record at the funder ↗

Researchers

Barbara Casadei (EPMC Awardee)

Related Research

Grants with similar aims, by meaning.

Screening for Atrial Fibrillation
Identifying patients at raised risk of stroke due to paroxysmal or persistent atrial fibrillation in primary care populations
Afib - Investigating the influence of ethnicity in Atrial Fibrillation, focusing on the epidemiology, risk factors and outcomes; a population based study.
Atrial Cardiac Magnetic Resonance Imaging in Patients with Embolic Stroke of Unknown Source without Documented Atrial Fibrillation
Evaluation of electrocardiographic monitoring stategy to identify atrial fibrillation on patients with recent acute stroke. (Was CZG/3/4)

Original classification

None

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