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Poverty Doubles Risk of Heart Death

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Duke Health News 919-660-1306

ATLANTA -- In the first analysis of its kind, Duke
University Medical Center researchers have shown that the
poorest of poor Americans are more than twice as likely to die
of severe heart disease than similar patients with higher
incomes. Furthermore, it may be that the main explanation comes
from what happens in these patients' lives after hospital
discharge.

The researchers studied 2,207 patients enrolled in a
multi-center clinical trial in which they all received the same
standardized treatments. The analysis revealed that patients
with an annual household income of less than $10,000 had a
30-day mortality rate 2.6 times higher than those more well
off, and a six-month mortality rate 2.1 times higher.

"In a clinical trial, patients are supposed to receive
similar care, but actually did not," said lead investigator
Sunil Rao, M.D., who prepared the results of the Duke study for
presentation today (March 17) at the 51st annual scientific
sessions of the American College of Cardiology. "Despite the
standardization of many treatments, poverty was associated with
a lower rate of some evidence-based medications at the time of
hospital discharge and a lower rate of some procedures during
the hospitalization.

"After adjusting for these differences, poverty was still
associated with a generally worse outcome, suggesting that the
situation these patients return to may be responsible," he
continued. "It may be that once out of the hospital, these
patients return to risky habits such as smoking or bad diet, or
more likely they cannot afford the medications prescribed for
them to treat their heart disease."

Their findings raise important health-care policy issues,
the researchers say, since most of the very poor tend to be
elderly. In the current analysis, the average age of the
low-income group was 65.

"The elderly, whose numbers continue to grow, are those who
are the most impacted by heart disease," Rao continued. "They
keep coming to the hospital with heart problems, which we treat
and then send them home on medications they may have trouble
affording."

Past studies, which have been observational, have shown that
poor patients tend to have higher mortality rates after
suffering a heart attack. The problem with these studies, the
researchers said, is that instead of using solid income numbers
to measure socio-economic status, the studies used such
"proxies" as education levels or the median income for their
ZIP code.

In order to obtain more concrete income data, the Duke
researchers mined the results of the economic substudy of the
much larger PURSUIT (Platelet Glycoprotein IIb/IIIa in Unstable
Angina: Receptor Suppression Using Integrilin Therapy) trial,
which enrolled 10,928 patients in a study of a new drug to
prevent blood clots from forming in heart attack patients. In a
2,207-patient subanalysis of this multi-center trial, the
PURSUIT researchers asked about household incomes, in
increments of $10,000.

"This was the first time that this type of information was
collected in an American clinical trial in cardiology," Rao
said. "Since everyone enrolled in a specific clinical trial
receives the same standardized care while in the hospital, this
set of data gave us a unique opportunity to look at these
economic issues without being clouded by other factors."

Of the 2,207 patients, 22 percent had household incomes
under $10,000 per year. They tended to be female, older and
have such other ailments as hypertension, diabetes and heart
failure. They were also less likely to receive medications that
past clinical trials had demonstrated to be effective, and they
were also less likely to receive revascularization
procedures.

"However, once we controlled for all these risk factors and
differences in care, the poor still had a significantly higher
short- and long-term risk of having another heart attack or
dying," Rao said.

For the past decade, Duke cardiologist Eric Peterson, M.D.,
senior member of the research team, has been conducting
research on discrepancies between outcomes for elderly and
African-American patients. He believes that this current study
represents a significant step forward in better understanding
the complex issues of socio-economic status and outcomes in
heart patients.

"What makes the results of this study so important is that
within the setting of a clinical trial, you would expect the
outcomes to be similar," Peterson said. "We looked at the
obvious reason why there might be such a discrepancy -- fewer
procedures, less usage of evidence-based medicines, or that
they may have been sicker when they enrolled in the trial.

"Now, based on this study, the answers are less clear in
that the differences we find are only partially explained by
these factors," Peterson continued. "We have to spend more time
looking at the larger issue of the continuity of care and
long-term compliance issues to ensure that all patients obtain
the same outcomes from medical care."

The Duke team has several projects under way to better
understand what happens to patients after discharge. In one,
they plan to monitor how compliant patients are with their
medications 180 days after discharge, as well as finding out if
these patients have a solid social support network to take care
of them.

The PURSUIT trial was funded by COR Therapeutics, San
Francisco, Calif. The Duke Clinical Research Institute
supported Rao's analysis.

Other members of the team, all from Duke, are Padma Kaul,
Ph.D., Kristin Newby, M.D, Robert Harrington, M.D., and Daniel
Mark, M.D.

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