Heart Problems Before Stroke Make for Worse Cognition After

Having a stroke is a strong risk factor for cognitive decline and dementia.

Having cardiovascular disease before suffering a stroke increases cognitive decline and likelihood of dementia after, according to a new study.

Researchers found that stroke survivors with the highest pre-stroke cardiovascular risk had more than twice the risk of developing dementia within 10 years compared with those at the lowest risk. They also experienced more rapid declines in overall thinking ability, even after researchers accounted for cognitive function before the stroke occurred. The findings suggest that managing cardiovascular risk factors before a stroke may help improve long-term brain health afterward.

The study pooled data from four large U.S. population studies and included 1,808 adults who experienced a first stroke but did not have dementia beforehand. Researchers tracked participants' changes in memory, thinking, and executive function for years following their stroke.

What is Cardiovascular Disease

Cardiovascular Disease (CVD) refers to diseases of the heart and blood vessels, heart attack, atherosclerosis (plaque deposits in the arteries), abnormal heart rhythms, and heart valve problems. High blood pressure can cause heart disease. CVDs are the leading cause of death around the world. 

Cardiovascular disease seems to make the brain more vulnerable. CVDs can damage small blood vessels in the brain, increase inflammation, promote brain shrinkage, or accelerate other detrimental changes in the brain, making a stroke more injurious and more difficult to heal from.

Many treatments exist for cardiovascular diseases. Early treatment is most effective.

Lifestyle is an important factor in limiting CVD risk. Exercise, eating a healthy diet high in fruits and vegetables, and avoiding taboo, alcohol, and exposure to air pollution are recommended. Management of diabetes and high cholesterol reduces risk of CVDs.

Cardiovascular Health May Influence Recovery

Researchers estimated each participant's risk of developing atherosclerotic cardiovascular disease (ASCVD), when cholesterol builds plaques in the arteries, before their stroke. They used the American Heart Association's PREVENT risk equation. This calculator estimates risk based on medical history, lab work results, body mass index, age, and cigarette use. 

People with higher cardiovascular risk scores had lower scores on tests of global cognition, memory, and executive function at the beginning of the post-stroke period. Their overall cognitive abilities continued to decline more rapidly after the stroke than participants with a lower cardiovascular risk calculation.

The association was strongest for global cognition, a broad measure of thinking abilities that includes attention, memory, language, and problem-solving. Interestingly, while participants with higher cardiovascular risk also had lower memory and executive function scores immediately after their stroke, those specific abilities did not decline faster over time.

Dementia Risk More Than Doubled

During the 10-year follow-up period, 182 participants developed dementia.

Researchers found a clear pattern: dementia risk was higher with pre-stroke cardiovascular risk increase. Compared with participants in the lowest cardiovascular risk group, those in the highest two risk categories were at least 2.5 times more likely to develop dementia after their stroke. Overall, every 1% increase in pre-stroke cardiovascular risk was associated with a 5% increase in the risk of post-stroke dementia.

The researchers also estimated how quickly cognition declined over time. Stroke survivors in the lowest cardiovascular risk group were projected to take nearly 18 years to experience a clinically meaningful decline in global cognition. Those in the highest risk group were projected to reach that same level of decline in less than eight years.

Reducing cardiovascular risk factors before a stroke occurs may ultimately help preserve cognitive function afterward.

Stroke survivors with high cardiovascular risk should be monitored closely for signs of cognitive decline and dementia.