“Hidden” cerebrovascular changes are common in patients with heart disease, regardless of whether they have experienced a stroke, Australian research suggests.
The team from the George Institute for Global Health in Sydney conducted a meta-analysis of 221 observational studies published between 1988 and 2022, comparing the prevalence of silent brain infarction (SBI) and cerebral small vessel disease (CSVD) in adults with heart disease with or without recent stroke.
Cardiac conditions among the cohort included coronary artery disease, heart failure or cardiomyopathy, heart valve disease, and patent foramen ovale.
Findings showed that in patients with AF, just over one-third had any form of SBI (35%), a quarter had lacune (25%) and almost two-thirds had white matter hyperintensity/hypoattenuation (62%). A quarter had evidence of asymptomatic microbleeds in the brain tissue (27%) and over one half had brain atrophy (57%).
The findings were comparable across patients with different heart diseases except for those with patent foramen ovale, who had a lower prevalence of SBI and CSVD.
Writing in Neurology [link here], the researchers said prevalence of SBI possibly attributed to cardioembolism or moderate-to-severe covert cerebrovascular changes was 4%–17% for SBI, 15%–30% for white matter hyperintensity/hypoattenuation, and 9%–13% for multiple cerebral microbleeds.
There were no differences in the prevalence of SBI between those with or without a recent stoke and no apparent sex differences in the results, the researchers noted.
While they identified a difference in the prevalence of SBI and white matter hyperintensity/hypoattenuation between those with and without heart disease, there was no evidence of a difference in cerebral microbleed prevalence.
Lead author Dr Zien Zhou from The George Institute for Global Health said that identifying these changes could play an important role in treatment selection since patients with heart disease were often overlooked for routine brain imagining.
“While several potential mechanisms of the association between heart disease and hidden cerebrovascular injury have been proposed, the two conditions share common risk factors such as ageing, hypertension, type 2 diabetes, hyperlipidaemia, and smoking,” he said.
“It’s possible that a gradual decline in cardiac output in some patients with heart disease might affect how much blood is reaching the brain tissue, contributing to vascular changes and cognitive dysfunction in these patients.
“It’s also possible that hidden brain changes and cognitive dysfunction are a consequence of tiny blood clots traveling to the brain through the arterial circulation after forming in the heart.”
Dr Zhou said that more research was needed to help establish the exact causes of the brain changes and the implications for managing such patients.
“We need to know whether performing an additional MRI in those considered for anticoagulation therapy – which is required for most people with heart disease – would be cost-effective in terms of preventing unwanted side effects,” he said.
“But refining the risks of brain clots and bleeds from anticoagulants and using this information to make the best treatment choice could improve treatment safety for people with heart disease.”