It is natural for a person’s memory and thinking abilities, or cognitive function, to decline gradually with age — even when they are otherwise healthy. However, new research suggests that the rate of cognitive decline may accelerate after a person experiences a heart attack or angina.

 

Studies that have explored the relationship between circulation problems and cognitive decline have usually focused on conditions that affect the brain’s blood supply, such as stroke.

 

However, few earlier studies examined the long-term connection between incident coronary heart disease (CHD) — including heart attacks and angina — and cognitive decline.

 

A recent study published in the Journal of the American College of Cardiology is unique because it tracked cognitive changes both before and after the occurrence of CHD.

 

The researchers concluded that incident CHD is associated with accelerated cognitive decline after the event, but not before it occurs. They believe the findings highlight an important long-term relationship between coronary heart disease and cognitive decline.

 

Lead and corresponding study author Wuxiang Xie, Ph.D., explains that because there is currently no cure for dementia, detecting and managing early signs of cognitive decline is crucial to delaying the progression of the condition.

 

“Even small differences in cognitive function can result in an increased risk of dementia in the long term,” explains Xie, who holds research positions at Peking University Clinical Research Institute in China and the School of Public Health at Imperial College London in the United Kingdom.

 

Coronary heart disease, also known as coronary artery disease, develops when the arteries that supply blood to the heart become narrowed and restrict blood flow.

 

This narrowing occurs because fatty deposits, known as plaques, accumulate inside the artery walls. Medical professionals refer to this process as atherosclerosis.

 

Reduced blood flow prevents the heart muscle from receiving sufficient oxygen, increasing the likelihood of a heart attack. The reduced blood supply can also cause chest pain, commonly known as angina.

 

According to the World Health Organization (WHO), coronary heart disease is the leading cause of death worldwide. In 2016 alone, the condition was responsible for more than 9 million deaths.

 

Xie and his colleagues believe their study is one of the largest investigations examining cognitive decline before and after a diagnosis of coronary heart disease.

 

Their analysis included data from 7,888 participants aged 50 years and older who were enrolled in the English Longitudinal Study of Ageing (ELSA).

 

The ELSA study collected data twice each year between 2002 and 2017. At the beginning of the study period, none of the participants had experienced a heart attack, angina, or stroke, and none had been diagnosed with dementia or Alzheimer’s disease.

 

The researchers excluded individuals who did not complete all cognitive assessments or who experienced a stroke during the median follow-up period of 12 years.

 

During the study, participants completed three types of cognitive tests conducted over eight assessment waves. These tests measured verbal memory, semantic fluency, and temporal orientation, which refers to a person’s sense of time.

 

During the study period, 5.6% of participants experienced either angina or a heart attack. Individuals in this group showed a faster decline in cognitive performance compared with those who did not experience a coronary heart disease event.

 

Participants who developed angina demonstrated a faster decline in temporal orientation. Meanwhile, those who experienced heart attacks showed more rapid declines in verbal memory and semantic fluency.

 

The study authors noted that incident coronary heart disease was significantly associated with faster cognitive decline following the diagnosis, although it was not linked to cognitive changes in the years before the event or to short-term changes immediately afterward.

 

The researchers speculate that reduced oxygen supply to the brain may explain the connection between coronary heart disease and accelerated cognitive decline.

 

Previous studies have linked coronary heart disease to disruptions in blood flow to the brain and to cerebral microinfarcts — small areas of brain tissue damage caused by limited blood supply.

 

These findings suggest that coronary heart disease may contribute to small vessel disease, which is considered a major factor in the development of dementia among older adults.

 

Because of these risks, the researchers emphasize that patients who experience heart attacks or angina should receive careful long-term monitoring of their cognitive health.