For people who have coronary artery disease (CAD), mental stress is associated with recurrent heart attacks and blockages of the coronary arteries requiring angioplasty. Laboratory tests that simulate stressful situations trigger ischemia (reduced blood flow to the heart) in 40% to 70% of people with CAD. However, studies of mental stress and CAD have not examined the death rate among CAD patients who experience mental stress. A study recently published in Circulation suggests that CAD patients who are regularly exposed to mental stress may be at increased risk of dying from any cause.

About the study

Researchers from several U.S. medical schools collected and analyzed follow-up data on 196 CAD patients from the Psychological Investigations of Myocardial Ischemia (PIMI) Study. Only 26 of the 196 PIMI participants were women. CAD patients were excluded from the PIMI study if they had a serious noncardiac illness, unstable angina, or neurologic disease. Patients who could not safely stop taking cardiac medications or who had undergone angioplasty or thoracic surgery were also excluded.

In the PIMI study, patients had undergone exercise stress tests and mental stress tests designed to see if physical or mental stress induced ischemia. A 5-minute speech test was used to simulate a mentally stressful situation. The patient role-played the part of a person whose close relative was being mistreated in a nursing home.

After an average of 5 years of follow-up on the PIMI patients, the researchers checked the Social Security death records to determine which patients had died. The researchers compared the number of deaths among CAD patients who had ischemia during the speech test with those who did not.

The findings

During the 5-year follow-up period, CAD patients who had ischemia during the speech test were nearly 3 times more likely to have died than their counterparts who did not have stress-induced ischemia. In calculating this statistic, the researchers factored in other factors that could influence mortality, such as age, history of heart attack, diabetes, high blood pressure, and tolerance on the exercise stress test.

Although these results are interesting, there are limitations to this study. Because there were very few women in this study and none of them died during the 5-year follow-up period, more research is needed to understand how stress-induced ischemia affects mortality risk among female CAD patients. It's also not clear what role stress-induced ischemia plays in nonfatal cardiovascular events, because no information on nonfatal events was collected. In addition, this study only examined the total death rate, so it's not known if the people died of causes related to their CAD.

How does this affect you?

This study provides evidence that if you have CAD, managing your stress levels may be as important as eating a heart healthy diet and exercising regularly. To help reduce mental and emotional stress in your life, consider learning relaxation exercises, yoga or tai chi, or talking to a counselor about problems or stressful relationships in your life. Talk to your health care provider about which stress management options may be best for you, and request a referral to a stress management program.