Stress triggers fatal heart attacks, study says

You probably know the main risk factors for heart disease: high blood pressure, high cholesterol, smoking, diabetes, obesity and a sedentary lifestyle. It’s likely that your doctor has checked you more than once for these risks and, hopefully, offered advice or treatment to help you avoid a heart attack or stroke.

But has your doctor also asked you about the level of stress in your life? Chronic psychological stress, as recent studies indicate, can be as important — and possibly more — to your heart health as traditional heart risk factors.

In fact, in people with less healthy hearts, mental stress outweighs physical stress as a potential trigger for fatal and non-fatal heart attacks and other cardiovascular events, according to a recent study.

The new report, published in November in JAMA (Journal of the American Medical Association, in Portuguese), evaluated the evolution of 918 patients known to have underlying but stable heart disease to see how their bodies would react to physical and mental stress.

Participants underwent standardized stress tests to see if their hearts developed myocardial ischemia — significantly reduced blood flow to the heart muscles, which can be a trigger for cardiovascular events — during one or both forms of stress. Then the researchers followed them for four to nine years.

Among study participants who experienced ischemia on one or both tests, this adverse reaction to mental stress had a significantly greater impact on patients’ hearts and lives than physical stress. They were more likely to have a nonfatal heart attack or die of cardiovascular disease in the following years.

I wish I had known this in 1982, when my father had a heart attack that nearly killed him. Upon leaving the hospital, he was warned about the risk of physical stress, such as not lifting anything heavier than 30 kilos. But he was never warned about undue emotional stress, or the risks of overreacting to frustrating circumstances, such as when the driver in front of him drives too slowly into a no-go zone.

The new findings underscore the results of a previous study that evaluated the relationship between risk factors and heart disease in 24,767 patients from 52 countries. Patients who experienced a high level of psychological stress during the year prior to study entry were found to be twice as likely to have a heart attack during an average follow-up of five years, even when traditional risk factors were taken into account. consideration.

The study, known as Interheart, showed that psychological stress is an independent risk factor for heart attacks, similar in heart-damaging effects to more commonly measured cardiovascular risks, explained Dr. Michael T. Osborne, a cardiologist at Massachusetts General Hospital.

But what about the effects of stress on people whose hearts are still healthy? Psychological stress comes in many forms. It can occur acutely, caused by incidents such as the loss of a job, the death of a loved one, or the destruction of the home in a natural disaster.

A recent study in Scandinavia found that in the week following a child’s death, the parents’ risk of having a heart attack was more than three times the expected rate.

Emotional stress can also be chronic, resulting, for example, from ongoing economic insecurity, living in a high-crime area, or experiencing relentless depression or anxiety. In the Scandinavian study, bereaved parents continued to experience an elevated heart risk years later.

How stress harms the heart

The Doctor. Osborne was part of a team of experts led by Dr. Ahmed Tawakol, also of Massachusetts General Hospital, of an analysis of bodily reactions to psychological stress. He said the accumulating evidence of how the brain and body respond to chronic psychological stress strongly suggests that modern medicine has overlooked a critically important danger to heart health.

It all starts in the brain’s fear center, the amygdala, which reacts to stress by activating the so-called fight-or-flight response, triggering the release of hormones that over time can increase body fat levels, blood pressure, and insulin resistance.

In addition, as the team explained, the cascade of stress reactions causes inflammation in the arteries, promotes blood clotting, and impairs blood vessel function, all of which promote atherosclerosis, the arterial disease that underlies most heart attacks and strokes.

The team of Dr. Tawakol explained that advanced neuroimaging tests have made it possible to directly measure the impact of stress on various tissues in the body, including the brain.

A previous study of 293 people initially free of cardiovascular disease, who underwent whole-body scans that included brain activity, had a telling result. Five years later, subjects with high amygdala activity showed higher levels of inflammation and atherosclerosis.

This means that people with high levels of emotional stress have developed biological evidence of cardiovascular disease. In contrast, said Dr. Osborne, “people who are not very tense” are less likely to experience the effects of stress on the heart.

The researchers are now investigating the impact of a stress-reduction program called Smart-3RP (which stands for Relaxation Response Resilience Program and Training in Stress Management and Resilience) on the brain, as well as biological factors that promote stress. atherosclerosis.

The program is designed to help people reduce stress and increase resilience through mind-body techniques such as mindfulness-based meditation, yoga and tai chi. Such measures activate the parasympathetic nervous system, which calms the brain and body.

Deactivating stress and its effects

Even without a formal program, Osborne said, individuals can minimize the body’s harmful stress reactions. One of the best ways is with regular exercise, which can help reduce stress and inflammation throughout the body.

Because poor sleep increases stress and promotes arterial inflammation, developing good sleep habits can also reduce your risk of cardiovascular damage. Adopt a consistent bedtime and wake time pattern, and at bedtime avoid exposure to screens that emit blue light, such as smartphones and computers, or use blue light filters for these devices.

Practice relaxing measures like mindfulness meditation, calming techniques that slow breathing, yoga, and tai chi.

Several common medications can also help, said Dr. Osborne. Statins not only lower cholesterol, they also fight arterial inflammation, resulting in a cardiovascular benefit greater than their mere cholesterol-lowering effects.

Antidepressants, including the anesthetic ketamine, can also help minimize excessive amygdala activity and relieve stress in people with depression.

Translated by Luiz Roberto M. Gonçalves