Women under the age of 50 who have suffered a recent heart attack are more likely to experience myocardial ischemia—which causes a decrease in blood flow to the heart—in the presence of psychological stress, a recent study conducted at Emory University in Atlanta found.
The Myocardial Infarction and Mental Stress (MIMS) study followed 49 men and 49 women, between the ages of 38 and 59, all of whom had suffered a heart attack within the past six months. The researchers measured how the patients responded to two kinds of stress: exercise-induced and mental stress. To test mental stress, the participants were given a public speaking task, in which they were allotted a short amount of time to prepare a speech on a real-life stressful situation, like a relative being mistreated in a nursing home.
The participants’ hearts were then examined via SPECT (single-photon emission computed tomography) to determine the blood flow within the heart. The study participants then underwent a standard exercise stress test on a treadmill at a later date.
Why Women Under 50?
The results of the study, which were presented at the American Heart Association Scientific Sessions meeting in Dallas on Nov. 20, found that 52 percent of the women under 50 experienced mental stress-induced ischemia, as opposed to 25 percent of the men in their same age group.
"We saw a dramatic difference in mental stress-induced ischemia specifically in younger women. In addition, when ischemia was graded in a continuous way, we saw that it was twice as severe among the younger women,” Dr. Viola Vaccarino, study leader and chair of the Department of Epidemiology at Rollins School of Public Health, said in a press release.
The two factors that showed the most dramatic differences between the sexes were inflammation and heart rate variability. To determine the levels of inflammation, the researchers measured the amount of interleukin-6 (IL-6)—a byproduct of inflammation—in the patients’ blood before and after the public speaking task. In both cases, women under 50 fared much worse than men of the same age, with more IL-6 present in their blood and a much lower heart rate variability in response to the mental-stress test.
The researchers noted that while cases of women under 50 suffering heart attacks are generally rare, the women in the study were more often poor and of minority race, in addition to having higher rates of depression and a history of sexual abuse.
"Yet if we look at the statistics, factors such as poverty, race, and depression do not explain the difference," Vaccarino added. "Yes, women have more stressors, but our data show that women also may be more vulnerable to the effects of mental stress on the heart."
Vaccarino hopes that these results will encourage the medical community to pay closer attention and take into account emotional and psychological stress when treating women who have had heart attacks.
Can Estrogen Treatment Help with Women's Heart Health?
A recent follow-up to a long-term study from the Women’s Health Initiative (WHI) examining the effects of estrogen therapy on postmenopausal women found that this hormone therapy correlated to a significant reduction in the risk of heart disease and mortality for women in their 50s.
However, the researchers noted that despite this benefits for women in their 50s, the opposite was true for women in their 70s.
An earlier study by the WHI saw no change in the risk of heart attack as compared with the placebo group. When the estrogen therapy was combined with progestin, another type of hormone, there was an increased risk of heart attack, in addition to an increased risk for breast cancer and stroke.