A heart attack may affect more than just your cardiovascular health — it could also increase the risk of faster memory loss and cognitive decline as you age.
New research has found that heart attack survivors had a 5 percent higher yearly risk of developing cognitive impairment, compared with people who never had a heart attack — suggesting that protecting heart health may also help preserve brain function later in life.
“There is emerging data that heart and brain health are intimately connected,” says Shyam Prabhakaran, MD, professor and chair of neurology at the University of Chicago, who specializes in vascular neurology who wasn’t involved in the new study. “What’s good for your heart is often also good for the brain, and vice versa.”
Heart Attacks, Including ‘Silent’ Ones,’ Linked to Cognitive Decline
The study followed more than 20,000 Black and white adults enrolled in a long-term U.S. health study for roughly a decade to analyze the potential link between a previous history of heart attack and cognitive function over time.
Participants underwent a medical interview and electrocardiogram at the start of the study to determine if they’d had a heart attack at any point in their past.
Then, during the 10-year study period, researchers tracked changes in cognitive function using yearly or biannual cognition tests. One test, for instance, asked participants to name as many animals as possible in 60 seconds. Lower scores suggested worse cognitive performance.
Researchers found:
- People who’d had a heart attack were 5 percent more likely to experience signs of cognitive decline each year, compared to those who didn’t have a previous heart attack.
- People who experienced a “silent” heart attack (an undiagnosed heart attack with symptoms that are mild, atypical, or unnoticed) also had an increased rate of cognitive decline, compared with those without a prior heart attack history.
“Our study found that those who have had a heart attack, including silent heart attacks, are one of those groups at higher risk. It’s important for clinicians who care for heart attack survivors to also provide counseling on ways to avoid cognitive decline and dementia.”
How Does a Heart Attack Affect the Brain?
Previous evidence suggests that a heart attack may cause blood vessel damage throughout the body, including the brain, says Fernando Testai, MD, PhD, director of vascular neurology and professor in the department of neurology and rehabilitation at the University of Illinois in Chicago. Dr. Testai, who wasn’t involved in the new study, has authored a recent national guideline on the association between heart disease and brain health.
Cardiovascular events like a heart attack may contribute to cognitive impairment via several pathways, he says including reduced blood flow to the brain, inflammation, vascular damage, tiny “silent” strokes or brain injuries, and changes in the blood-brain barrier.
“We have long known that cardiovascular risk factors affect both the brain and the heart,” says Michael J. Schneck, MD, a professor of neurology and neurosurgery at Loyola University in Chicago, who specializes in vascular neurology and neurocritical care.
“For example, the same risk factors that result in heart disease also result in strokes. Significantly, patients with cardiovascular risk factors (including hypertension, hyperlipidemia [high cholesterol], and/or diabetes) also have a greater risk of Alzheimer disease,” Dr. Schneck says. “This is because those factors result in microvascular changes to the brain vessels that affect blood flow but also brain metabolism.”
Still, more studies are needed to understand the specific mechanisms behind why and how heart attacks may contribute to cognitive decline, and whether specific interventions after a heart attack could help lower risk for dementia.
“A heart attack may represent an early warning sign not only for future cardiac problems, but also for future cognitive vulnerability,” says Dr. Prabhakaran.
The Study Has Some Limitations
Testai points out that while the researchers adjusted for many factors that could impact cognitive decline, they did not consider everything, including some established risk factors like sleep disorders, poor diet, obesity, and a family history of Alzheimer’s.
The researchers also noted that the screening tool used was relatively simple, rather than more detailed neurological testing that could capture specific types of dementia.
“To me, that’s the biggest limitation, that the findings are based on a screening tool,” says Michelle Johansen, MD, PhD an associate professor of cerebrovascular neurology at Johns Hopkins University in Baltimore, who wasn’t involved in the research. “That’s not to say that these results aren’t valid, they’re just more limited.”
Because the study was observational, it can’t prove that heart attacks directly caused cognitive decline — only that there is a connection.
In addition, participants were drawn from an ongoing study focused on stroke risk in the southeastern United States representative of two ethnic backgrounds, which limits how broadly the findings could apply to all populations. And self-reported data from participants was also used, rather than confirmed heart attack medical history.
Tips for Healthy Heart and Brain Aging
“It is never too late or too early to engage in life-style modifications to improve brain health,” Schneck says. “Even a little amount of exercise is better than no exercise; even some improvement in diet will help. Anything you can do to reduce risk — such as weight loss, cigarette cessation, walking, reading— will help.”
Schneck also recommends regular talks with your healthcare provider about improving your heart health. “As with cars, so with people: Preventive maintenance with regular visits, just like oil changes for cars or checking the brakes for electric cars, can have a positive impact on your health,” he says.
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