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 These assessments have been used for decades to determine patients’
risk of dying from cardiovascular disease. But the results can be
inaccurate because the scoring system was developed based on
experiments done only in middle-aged men, said senior study author
Dr. Leslie Cho, director of the Women’s Cardiovascular Center at the
Cleveland Clinic in Ohio.
“There has been no good data to support its use in women,” Cho said
by email. “The score was likely underestimating risk for some women,
while overestimating it for others, based on their age.”
At the same time, scores from the most commonly used version, known
as the Duke Treadmill Test, focus primarily on exercise ability and
don’t account for health problems like diabetes or high blood
pressure that can influence the risk of developing cardiovascular
disease, Cho noted.
For the current study, Cho and colleagues examined results from a
new assessment designed to better estimate the risk of death from
heart disease in both men and women.
Researchers analyzed data on more than 100,000 adults seen at
Cleveland Clinic from 2000 through 2010 or the Henry Ford Health
System from 1991 through 2009.
All of the study participants had exercise tests.
Researchers could also see medical records to determine other risk
factors for heart disease such as high blood pressure, diabetes,
obesity or elevated cholesterol levels.
Among the subset of almost 60,000 people seen at Cleveland Clinic,
half of the patients were at least 54 years old. They ranged in age
from 45 to 63, and half of them were followed for at least seven
years.
Roughly 60 percent of participants were men. The men generally had
higher exercise capacity and higher odds of a history of coronary
artery disease than the women, researchers report in JAMA
Cardiology.
In this group, 1,779 men, or 5 percent, died during the study
period, compared with 742 women, or 3.1 percent.
For both sexes, death was associated with older age, lower body
weight, diabetes, high blood pressure, elevated cholesterol levels,
a current or previous smoking habit, and history of health issues
like heart attack, artery disease, stroke, heart failure, kidney
disease and chronic obstructive pulmonary disorder.
When researchers developed sex-specific risk scores, however, they
found a history of diabetes was associated with mortality in women,
while a history of heart failure and hypertension were associated
with mortality in men.
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Researchers tested the accuracy of their sex-specific risk scores by
applying these ratings to a separate group of more than 49,000
patients seen at Henry Ford.
While exercise capacity was still the biggest predictor of risk,
accounting for these other patient characteristics offered a more
accurate picture of individual risk in men and women, the authors
conclude.
One limitation of the analysis is that researchers focused on deaths
from all causes rather than mortality tied only to cardiovascular
disease, the authors note. They also lacked access to imaging data
that might help verify, for example, the extent of artery disease.
Even so, the testing criteria proposed in the study may more
accurately reflect women’s risk of dying from heart disease because
the traditional scores generally didn’t account for the fact that
men tend to have better exercise capacity than women, noted Dr.
Armin Zadeh, a researcher at Johns Hopkins University in Baltimore
who wasn’t involved in the study.
“It's not so much that their risk factors are different but that an
important component of the exercise treadmill testing is the
exercise capacity which tends to be greater in men than women,”
Zadeh added by email. “Therefore, the old criteria set an unfairly
high bar for women to clear for the same prognostic value.”
Looking at women separately can offer a more accurate picture of how
well women perform on exercise tests based on what would be
considered a good or bad performance for their female peers, Zadeh
noted.
“When not separating scores, women will be held to a higher
standard, which will bias results,” Zadeh said.
SOURCE: http://bit.ly/2dWSV1f JAMA Cardiology, online October 26,
2016.
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