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African-American Heart Attack Patients Fare Worse Long Term

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Duke Health News 919-660-1306

DURHAM, N.C. -- In the largest analysis of its kind,
researchers from the Duke Clinical Research
Institute
(DCRI) found that African-American heart attack
patients have a 1.7 times higher death rate than Caucasians one
year after being treated in the hospital.

The researchers also found that while mortality rates within
the first 30 days after treatment were similar between the two
ethnic groups, African-Americans were more likely to suffer a
major bleeding event or a stroke.

Importantly, differences between Caucasians and
African-Americans in terms of patient characteristics and
cardiovascular risk factors accounted for only a portion of the
disparity in long-term mortality outcomes, according to Duke
cardiologist Rajendra Mehta, M.D.

"No matter what patient or treatment feature we adjusted for
statistically, this disparity in long-term outcomes still
remained," said Mehta, who presented the results of the Duke
analysis Nov.9, 2004, at the American Heart Association's
annual scientific sessions in New Orleans.

"There has to be something else going on that we don't fully
understand," Mehta said. "In order to improve the outcomes for
African-American heart attack patients, we feel that there
should be prospective clinical study to help us understand what
these factors may be and how best to address them."

While the current analysis was not designed to uncover the
reasons for these differences, behind, Mehta said he suspects a
combination of socio-economic factors, including compliance
with long-term drug therapy, mistrust of the medical system,
and lack of medical insurance.

According to Mehta, health professionals have assumed
African-Americans with coronary artery disease suffer worse
outcomes because of their higher prevalence of risk factors,
such as hypertension and diabetes, delays in seeking care,
lower quality of care and access issues.

However, most studies addressing these questions have
involved small numbers of patients or included patients with a
wide range of heart disease.

The Duke team chose to focus on a specific group of patients
who suffered a kind of heart attack known as an acute
ST-elevation myocardial infarction (STEMI). This
categorization, based on an electrocardiogram test, is the most
severe form of heart attack with the worst short-term outcomes
as well as long-term outcomes.

STEMI patients are typically treated quickly in the hospital
with clot-busting drugs to restore blood flow to the heart.
Many then receive a subsequent angioplasty procedure or
coronary artery bypass surgery.

For its analysis, the team pooled data from five different
multi-center clinical trials of fibrinolytic, or clot-busting,
agents. Of the 32,419 patients in the analysis, 5.1 percent
were African-American.

"We found that, when compared to the Caucasian patients, the
African-Americans tended to be younger, more likely female, had
higher prevalence of cardiovascular risk factors, and were more
likely to have higher blood pressure and heart rates," Mehta
said. "However, African-Americans also tended to have arteries
that responded better to treatment, more likely to have less
severe coronary artery disease, and were less likely to have
multi-vessel disease."

The researchers found that 6.7 percent of African-Americans
had died within thirty days after treatment, compared to 6.6
percent of Caucasian patients. Furthermore, 5 percent of
additional African-American patients had died within one year
after treatment, compared to 2.9 percent of additional
Caucasians.

"What we found particularly intriguing was that
African-Americans had worse outcomes despite their average
younger age," Mehta continued. The African-Americans were on
average 57 years old, compared to 61.1 for Caucasians. "It is
well-known that older age is one of the strongest predictors of
adverse outcomes for heart attack patients."

The 5.1 percent participation rate of African-Americans in
the trials from which the data was drawn is consistent with the
historical range of 2 percent to 9 percent African-American
participation of in other cardiology trials, Mehta said.
African-Americans make up approximately 13 percent of the U.S.
population.

"It has been shown that African-Americans are hesitant to
participate in clinical trials and that there is a lack of
trust in the medical profession, when compared to Caucasians,"
Mehta said. "This trend is seen more so in certain regions of
the country."

Because of the historical under-representation of
African-Americans in clinical trials, Mehta said that there is
a paucity of data that might help explain the disparity in
outcomes. He added that clinical trials involving large numbers
of African-Americans will be required to gain reliable data on
the epidemiology and biology of heart disease.

"Our data, combined with that gathered from previous
studies, show a significant difference in the clinical features
and patterns of care between African-Americans and Caucasians,"
Mehta said. "These differences, coupled with poorly understood
genetic, biologic and other socio-economic factors appear to
result in higher mortality rates for African-Americans.

"This data also shows that just treating the heart attack
acutely may not be enough," he continued. "We also need to
focus on improving such issues as compliance, access to care,
and trust in the health care system."

The five clinical trials from which data was drawn were
GUSTO-I, GUSTO-IIb, GUSTO-III, ASSENT-2 and ASSENT-3. Mehta's
analysis was supported by the DCRI.

Other members of the Duke team were SeeHyang Sohn, Karen
Pieper and Christopher Granger, M.D. David Marks, M.D., Medical
College of Wisconsin, Milwaukee, was also a member of the
team.

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