Stress Linked to Worse Outcomes for Young Women with Heart Disease

Stress is much more harmful for young and middle-aged women
with cardiovascular disease than for other patients, new research indicates.

“Younger women under the age of 55 tend to do worse than
older individuals and men,” said University of Alberta cardiologist Paolo
Raggi, MD. “The long-term complication rate and the recurrence rate for heart
attacks are much higher.”

Researchers followed 662 heart patients for up to three
years. Each person was assessed for symptoms of mental illness, including
depression, post-traumatic stress disorder (PTSD), anxiety, anger, hostility
and perceived stress. 

The researchers found that in women, higher stress
was associated with higher rates of adverse outcomes including death,
myocardial infarction, stroke, heart failure or unstable angina. In fact, each
measured increase of stress on a psychological distress score was associated
with a 44 per cent increase in further cardiovascular events.

The study is one of dozens of papers produced by a group of
80 psychologists, psychiatrists, radiologists and heart specialists, including
Raggi, who have spent nearly a decade working together to understand the link
between heart disease and mental illness. 

“Why do patients with heart disease and associated
depression or stress fare worse than patients with the same heart condition but
no mental disorders? What are the mechanisms?” Raggi asked. “We don’t yet know
whether mental disorders are the cause of or worsen cardiovascular disease, or
if cardiovascular diseases induce mental disorders.”

While women in general, and specifically young women, are
less likely than men to develop cardiovascular disease, the researchers found
that when they do, they tend to have more serious outcomes. They postulate it
may be because of differences in the way men and women react to stress. In one
study, they examined which parts of men’s and women’s brains were
activated by taking brain scans while patients completed difficult math problems
or were asked to give speeches, both considered forms of simulated mental
stress.

The researchers found that men activate center that are
responsible for computation, defense and alertness, whereas women activate
centers that are more responsible for emotional responses such as sadness,
anxiety and depression.

“The emotional response of women to stress may be one of
the causes of their predisposition to more complications once they develop
coronary heart disease,” Raggi said. 

He explained that in a separate investigation, his team
found strong emotional stress response in women can lead to excessive
stimulation of the sympathetic nervous system, which speeds the heart rate
during stress, and less activation of the parasympathetic nervous system, which
slows the heart rate and modulates other important physiological
functions. 

In another study, the researchers found that women who
suffered a heart attack are twice as likely as men to experience mental
stress-induced myocardial ischemia (decreased blood flow to the heart due to
stress).

“In the long range, women with prior heart attacks who
suffer from prolonged stress may suffer recurrent episodes of reduced blood
supply to the heart and eventually experience another cardiac event,” Raggi
said.

He added the researchers are still investigating the
underlying causes of the fundamental differences between men and women, with
work funded by the U.S. National Institutes of Health. In one study, they found
higher biomarkers of inflammation in the blood of young women with heart
disease than in men of the same age. Based on those findings, the team will do
further testing using simultaneous scans of the brain and heart to determine
the role of inflammation in stress responses.

Raggi said that so far, medications to treat stress or
other mental disorders have not been shown to be effective in reducing adverse
heart outcomes. However, in a pilot study in which they trained eight patients with
coronary artery disease to control their neurological responses to stress using
biofeedback, the researchers showed blood flow to the heart was increased
compared with the control group. Raggi intends to pursue further investigation
along those lines.

The researchers conclude that patients with coronary artery
disease, especially women, should be assessed and treated for psychological
distress in addition to traditional heart disease therapy.

Sources: