Dec. 8, 1999 (Atlanta) -- "Calm down before you give yourself a heart attack!" Everyone's heard or thought something like that at some point in their lives. And for people with heart conditions, it's good advice. But how to effectively calm down is another thing entirely. That question might soon receive more research, thanks to the results of a new study.
Physical response to mental stress helps predict health outcomes for patients with coronary artery disease (CAD), according to a group of researchers whose work is published in the Dec. 1 issue of The American Journal of Cardiology. Ischemia, or lack of blood flow to the heart by blockages in the arteries, is a common cause of heart disease. Thus, a new direction for therapy may involve blocking the ability of mental stress to cause the heart to work harder in heart patients.
"Behavioral triggers are important in cardiovascular disease," senior author John S. Gottdiener, MD, tells WebMD. "Not only do they account for most of the episodes for cardiac ischemia, but they have importance for indicating the outcome for coronary artery disease ... While an exercise event is more potent [for showing blocked blood flow to the heart], most people don't have 20 to 30 episodes during the day where they're performing vigorous exercises. ... However, people are constantly mentally and emotionally engaged. ... So, the extent that those type of mental or emotional activities are able to affect the way blood flow goes to the heart in patients with coronary disease ... [has] become extremely important."
Gottdiener, who was a professor of medicine at Georgetown University Medical Center in Washington while participating in the study, says about half of the people who have restricted blood flow while exercising also will have restricted blood flow brought on by mental stress. Therefore, those heart patients who show signs of restricted blood flow from mental stress are at a greater risk of heart failure than are those who show the restricted flow on standard exercise tests.
The 79 patients included in this follow-up study had participated in two previous studies examining the effect of mental stress-induced ischemia on those with coronary artery disease. Tests were performed on these patients using either ultrasound or radionucleotide ventriculography (RNV), a procedure where radiated dye is injected into the person to help show areas where blood flow is restricted. These measurements, as well as heart rate and peak changes in blood pressure, were taken at rest, during mental stress, and during exercise. Mental stress was induced by public speaking and mental arithmetic tasks. New or worsened heart abnormalities were detected in 77% of patients during exercise testing and 57% during mental stress. Nearly all patients who experienced restricted blood flow during mental stress also experienced it during exercise.
For the latest portion of the study, 78 of these 79 patients were monitored for three to four years with respect to incidences of cardiac events, defined as minor or major surgery, nonfatal heart attacks, or fatal heart attacks. Twenty-eight cardiac events occurred during follow-up, and patients with ischemia brought on by mental stress experienced a cardiac event significantly more frequently than those without mental stress-induced ischemia (20 patients vs. eight, respectively).
"Our patients have been telling us for years that stress causes heart attacks," says Diane Becker MPH, ScD, who reviewed the study for WebMD. "Likewise, as health care providers, we have long known that mental stress is not good for people with known coronary disease. Sadly, we do not have effective treatments for stress. There is not one ounce of solid and generalizable evidence that we can reverse this process. Thus, clinically, we simply work with people to lower the stress in their lives through relaxation and simplifying their lifestyles. [We also] pay attention to what patients tell us and help them make good life choices. This in no way should be interpreted to mean that people should stop working or take medications."
"Worse," Becker says, "I would hate to see this have legal ramifications where someone could hold another person or employer liable for a stress-induced coronary disease event. We simply do not know enough about how to manage stress or whether this will affect outcomes. We simply can offer plain, common-sense recommendations. The old 'take it easy' advice is still all we have." Becker is a professor of medicine and director of the Center for Health Promotion at Johns Hopkins University.
However, Gottdiener, who is currently director of cardiac noninvasive imaging at St. Francis Hospital in New York, may have better news. "Right now," he says, "there's consideration being given to a therapeutic trial of mental stress-induced ischemia, where some of the possibilities include everything from behavioral therapy to psychoactive drugs. If [we] can block the ability of mental activation ... [to] produce ischemia, we can probably improve the outcome in a lot of people."
This research received funding from the National Institutes of Health and the Uniformed Services of the Health Sciences in Bethesda, Md.
- Ischemia, or lack or blood flow to the heart, is a common cause of heart disease that is often measured with exercise testing.
- About half of patients who experience ischemia during exercise also experience it during mental stress, and this group of patients is more likely to suffer adverse cardiac events.
- Physicians can advise patients to lower stress through relaxation and simplification of lifestyle, but further research is being conducted to learn more about stress reduction.