When you have a heart attack, your heart is not pumping oxygen to the rest of your body. This can restrict blood blow to the brain, causing cognitive impairment.

© izusek | Getty Images

Myocardial infarction, commonly known as a heart attack, is the most common cause of death in the western world. Although most people survive a heart attack, they may be left with disabilities caused by the heart attack. In fact, a heart attack is also the leading cause of disability. Heart attack research now shows that one common disability found after a heart attack is a mental disability, called cognitive impairment.

What Is Cognitive Impairment?

Cognitive impairment is any loss of high-level intelligence that includes brain functions like memory, attention, language, judgment, reasoning, and understanding. Cognitive impairment can be severe, like Alzheimer’s disease and or mild cognitive impairment that comes with aging. There are many causes of cognitive impairment, but all the causes result from damage to brain cells called neurons.

Cognitive Impairment and Heart Attack?

A heart attack is decreased blood flow through the arteries that supply your heart muscles. When your heart is not getting enough blood, it is not getting enough oxygen carried by your blood, so heart muscle cells become damaged and may die. Also, when you are having a heart attack, your heart is not pumping out blood to the rest of your body very well.

A heart attack deprives your body of oxygen, explaining heart attack symptoms like shortness of breath and dizziness. Another type of body cell that needs a constant supply of blood and oxygen are your brain cells, called neurons. Damage to neurons starts to occur quickly if blood flow is decreased, which can happen during a heart attack. Recent studies find that about half the people who have a heart attack have enough decreased blood flow to the brain to cause some cognitive impairment.

What Does the Research Show About Memory Loss After Heart Attack?

Back in 2011, a study reported in the American Heart Journal found that out of 772 patients who had a heart attack and were tested for cognitive function one month later, only about 45 percent had normal cognitive test results. About 30 percent had mild cognitive impairment and 25 percent had moderate to severe impairment. The authors of the study concluded that cognitive impairment after a heart attack could be a common problem and suggested that patients have support and assistance after coming home from a heart attack and that they participate in a cardiac rehabilitation program.

In 2019, one of the largest studies on cognitive impairment after a diagnosis of coronary heart disease was published in the Journal of the American College of Cardiology. It included close to 8000 patients. These patients did not have dementia before their heart disease diagnosis. Over a period of 12 years, they were tested for memory, language, and knowledge of present circumstances. Patients with a diagnosis of heart attack had significant impairment in all three tests over the 12 years. The authors of this study conclude that cognitive impairment after a heart attack is common and probably due to decreased blood flow. They suggested that the best way to prevent this type of impairment is to prevent heart disease, called primary prevention.

Most recently, in a study presented at the 2022 meeting of the American College of Cardiology, researchers pointed out the accumulating evidence of the link between heart attack and cognitive impairment. This study found a high rate of cognitive impairment in patients after a heart attack who had no diagnosis of cognitive impairment before their heart attack.

The researchers tested 220 patients with a cognitive test called the Mini-Mental State Examination. They tested at the beginning of the study and six months later.  According to the mini-mental exam, 40 to 41 percent of the patients had cognitive impairment right after the heart attack. At six months, the rate of cognitive impairment went down to between 33 and 34 percent. The authors of this study concluded that cognitive impairment after a heart attack may be both temporary and permanent and that patients after a heart attack should be checked regularly for any signs of cognitive impairment.

What Are the Symptoms of Cognitive Impairment?

You may notice symptoms of cognitive impairment yourself, but more often a friend or loved one will notice warning signs. These signs and symptoms may come and go at first, so it is important to tell your health care provider about them:

• Trouble remembering
• Asking the same questions over and over
• Telling the same stories over and over
• Difficulty learning new information
• Missing appointments
• Trouble concentrating enough to follow a conversation, book, or movie
• Trouble finding the right words when speaking, or losing your train of thought while talking
• Becoming easily confused and agitated
• Trouble doing simple tasks

Prevention and Treatment

All the things you do for heart health will also help protect your brain before or after a heart attack. Lifestyle changes that reduce your risk of heart disease and cognitive impairment include:

• Regular physical activity
• Proper sleep, at least seven hours every night
• Relaxation techniques to reduce stress
• The Mediterranean diet, which is low in saturated fat and features whole grains, fruits, vegetables, and fish
• Limiting your use of alcohol
• Not smoking
• Maintaining a healthy weight

Work with your doctor to control your blood sugar, blood pressure, and cholesterol. If you have sleep apnea, get that under control. You can also protect your brain by building up cognitive resilience. The more exercise you give your brain by doing brain-teasing puzzles or learning new activities that require thought and memory, the more you can lose some brain cells and still have enough reserve to avoid cognitive impairment.