Discovering hidden changes in the brain of people with heart disease

US – Brain blood vessel changes that increase the risk of stroke and dementia are common in those with heart disease, a study has found.

The study, published by the journal Neurology, is the most comprehensive systematic review of “hidden” brain changes in those suffering from a range of heart diseases to date.

The study’s lead author, Dr. Zhen Zhu from the George Institute for Global Health, said identifying these changes could play an important role in choosing treatments for these patients.

He added: “Although people with heart disease are two to three times more likely than the general population to suffer from changes in the brain’s vascular system, they are often overlooked, because these patients do not undergo routine brain imaging unless they have had heart disease.” With a stroke. But it can put them at greater risk of brain bleeding than medications typically used to treat or prevent blood clots. “Intracranial hemorrhage is a life-threatening complication with no proven treatment and a survival rate of less than 50%.”

Changes in the blood vessels in the brain that can only be detected by brain imaging such as silent cerebral infarction (SBI) and cerebral small vessel disease (CSVD) are known to occur more commonly in the elderly or those with high blood pressure.

Although it is not enough to cause obvious neurological symptoms, it can lead to subtle neurological deficits and increase the risk of stroke or dementia in the long term.

To determine the prevalence of these subtle or hidden cerebrovascular changes in adults with atrial fibrillation, coronary artery disease, heart failure or cardiomyopathy, heart valve disease, or patent foramen ovale (hole in the heart), researchers from the George Institute conducted an analysis Statistically based on 221 observational studies published between 1988 and 2022.

The results showed that among people with heart disease:

– Nearly one-third had any form of silent cerebral infarction

– A quarter of them had vacuoles (small cavities where nerve tissue died after a previous blockage or leakage from small arteries)

– Two-thirds of them have lesions in the white matter (damage to the protective layer around nerve fibers)

A quarter of them have evidence of small, asymptomatic hemorrhages in the brain tissue.

– More than half of them have cerebral atrophy (shrinking of the brain due to loss of neurons or connections between neurons).

The prevalence of these brain changes was generally the same between those who had and had not had a recent stroke, and there were no clear gender differences in outcomes.

Dr. Chu said that the study also confirmed that heart disease is one of the main causes of these changes that reflect the “weakness” of the brain.

He added: “While several potential mechanisms have been proposed for the association between heart disease and occult cerebrovascular injury, the two conditions share common risk factors such as aging, high blood pressure, type 2 diabetes, hyperlipidemia, and smoking.”

He continued: “It is possible that the gradual decrease in cardiac output in some people with heart disease may affect the amount of blood that reaches the brain tissue, which contributes to vascular changes and cognitive dysfunction in these patients.” It is also possible that hidden changes in the brain and cognitive dysfunction are the result of small blood clots that travel to the brain through the arterial circulation after forming in the heart.”

Dr. Chu emphasized that more research is needed to look into the exact causes of these brain changes and the implications for the management of these patients.

Source: Science Daily