Duke Researchers Find Heart Tests Used for Men Just as Effective for Women
NEW ORLEANS, LA. -- Two routine tests that have been used almost
exclusively in men have been shown to be just as accurate in detecting
heart disease and predicting outcomes in women.
in two separate studies the reliability of exercise treadmill tests and
myocardial perfusion imaging (MPI) in women, researchers at Duke
University Medical Center said physicians will be much better equipped
to screen and treat their women patients.
Treadmill testing will
provide an accurate way to screen those women who have symptoms but
who, in fact, do not have heart disease, the researchers concluded
after screening more than 1,600 women tested at Duke.
treadmill testing, the reliable and inexpensive workhorse of
cardiology, can predict heart disease as accurately in women as in men
is significant, the Duke researchers said, since cardiologists
traditionally skip treadmill testing in favor of more high-priced and
high-tech radiological tests for women patients with chest pain.
has long been the perception that we can't rely on non-invasive
techniques for women heart patients," said Leslee Shaw, research
associate at the Duke Clinical Research Institute (DCRI). "However, our
data demonstrate that the Duke Treadmill Score (DTS) provides equally
accurate information for women and men.
"This is a good message
for women -- treadmill testing is tried and true, and cost-effective,"
she said. "We will be able to screen out those women who don't, in
fact, have heart disease without sending them on for more invasive
diagnostic procedures. It is wonderful to have a screening test for
women that works, is inexpensive and is non-invasive."
disease is the leading cause of death for both women and men, and the
way women report symptoms makes it more difficult for physicians to
quickly diagnose heart disease, Shaw said.
clinical histories can be difficult to interpret, many physicians tend
to send their women heart patients directly to the more expensive and
invasive tests," Shaw said.
The DTS is a composite score based on
three different measurements taken while patients are undergoing an
exercise treadmill test -- duration of exertion, changes in the EKG
readings during the test, and the amount of chest pain reported by
patients. The DTS was developed by Duke in 1983 and is widely used by
cardiologists across the country. "After adjusting for such variables
as age, prior heart attacks, diabetes, hypertension and other factors,
we found that the DTS was the most important predictor of cardiac
survival," said study statistician Karen Kesler, who prepared the
findings for presentation Wednesday (Nov. 13) at the annual scientific
meeting of the American Heart Association. "The DTS reliably predicted
the risk of death in both men and women."
For the treadmill
study, researchers looked at 5,665 patients who were referred to Duke
for treadmill testing and subsequent catheterization from 1969 to 1991.
Of those patients, 1,617 were women. The study was supported by the
Duke Clinical Research Institute, which has been collecting and
analyzing data about heart disease for 27 years.
In the second
study, researchers demonstrated that the sophisticated MPI system can
now be used with confidence in detecting damaged heart muscle in women.
the past, cardiologists had tended to avoid MPI in women because it was
thought that breast tissue between the heart and the MPI camera could
lead to misleading images. However, the development of new
radioisotopes has allowed the cameras to make accurate readings in
women and heavy-set patients.
In an MPI test, trace amounts of radioactive isotopes are injected into the patient undergoing a stress test.
isotope is taken up by the blood and goes wherever it goes," said Shaw,
principal investigator of the END (Economics of Non-Invasive
Diagnostics) study, which looked at 8,411 patients. "Areas where there
is no flow show up as a 'hole' or a 'cold spot.' We can then clearly
see any areas of the heart that aren't receiving adequate blood flow."
disease, once was thought to be a man's disease, is killing men and
women in equal numbers, though the rates are increasing for women as
the rates for white men decrease, Shaw said.
"This decrease is
due to early detection of heart disease," Shaw said. "It is important
that in studies like these we can study large numbers of women and
develop accurate detection tools for women. Women also tend to be more
concerned about breast cancer than they are about heart disease, which
is unfortunate, because more women die from heart disease. The good
news is that we now have non-invasive tools to accurately diagnose
heart disease in women."