Could your personality be putting you at risk for a heart attack?Researchers are beginning to look beyond the accepted risk factors of heart disease, such as high blood pressure and high cholesterol, and are taking a closer look at mental health — exploring how factors such as personality and depression can raise the risk of a heart attack.
It’s well established that the immune system plays a role in the progression of heart disease. And studies have shown that sudden bursts of anger or stressful events can trigger a heart attack. But a recent review of these types of studies found that there are several psychological factors that influence heart disease through different mechanisms at various stages of the disease’s progression.
Dr. Willem Kop, of the Department of Medical and Clinical Psychology at the Uniformed Services University in Bethesda, Maryland says psychological risk factors for heart disease are classified into three categories: acute triggers, episodic factors, and chronic factors. His review is published in a recent issue of the journal Brain, Behavior, and Immunity.
To understand how mental health is related to heart disease and the immune system, Kop says it’s important to understand why heart attacks occur. As plaques accumulate along the walls of blood vessels they often become unstable. If a plaque ruptures, sticky particles called collagen spill into the arteries. The immune system responds by clotting this rupture off, treating it as if it were a cut on a finger. But when the clot fills the vessel, blood flow is blocked through the artery and the heart is deprived of oxygen.
"The immune factors that may play a role in plaque instability are actually activated by stress," said Dr. Kop.
Normally, when a person is stressed the arteries in the body, particularly those in the heart, become dilated. But in the case of heart disease, mental stress produces a narrowing of the coronary arteries.
"So the heart has to work harder to respond to the challenge," said Dr. Kop, because the heart is receiving less oxygenated blood through the constricted blood vessels.
Mental stress is an example of an acute risk factor. Kop says it can impair heart function in 30 to 60 percent of patients with heart disease. And outbursts of anger can double the risk of a heart attack in people with advanced coronary disease.
Episodic risk factors are not brief outbursts, instead these events last anywhere from two weeks to two years. Depression and exhaustion are the most common, and they are usually triggered by major stressful events, such as the loss of a job or the loss of a loved one. Episodic risk factors are associated with increased risk of a first heart attack, particularly during the first year of depression, according to Dr. Kop.
"Those episodic factors are associated with increased markers of inflammation, and C-reactive protein is one of the most pertinent ones," said Dr. Kop.
Studies have shown that high levels of C-reactive protein are associated with an increased risk of heart disease. And Dr. Kop says the association between depressive symptoms or fatigue and C-reactive protein is particularly strong in those over the age of 65 years. The good news is, according to Kop, the risk of a heart attack drops significantly after the first year of ongoing depression.
And finally, stable characteristics such as hostile personality, Type-A behavior pattern, and low socioeconomic status are associated with long-term risks for heart attack. These are considered chronic psychological risk factors. Low socioeconomic status results in greater exposure to pathogens, which can trigger the inflammatory immune response. Hostility causes lipids like cholesterol to be deposited along the arteries and also increases inflammation, which can lead to plaque rupture.
So researchers like Dr. Kop are now looking beyond diet, exercise, and family history to help diagnose a patient with heart disease.
"Aspecific complaints such as fatigue and depressive symptoms," said Dr. Kop, "may indicate in a small group of people a progression of underlying coronary disease."
And he suggests it may be good to do a blood work-up on these patients to look for certain inflammatory markers, like C-reactive protein, that can indicate heart disease risk.
A good diet and plenty of exercise continue to be the best means for preventing heart disease. Studies looking at psychological interventions to reduce depression have been inconclusive in their ability to reduce the incidence of heart attacks. But Dr. Kop believes focusing on mental health can play a role in better patient care.
"I think if we combine psychological interventions with optimal pharmacological interventions," said Dr. Kop, "you might add not only to patients quality of life—because it’s not fun to be having psychological distressful situations—but also you may have positive health outcomes."
