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Doctors
Can Predict Heart Failure Death
A quick analysis of patients hospitalized
for heart failure can pick out those at highest risk of dying,
Canadian physicians report.
"We found that a simple model using
data available in the initial hours of hospital presentation predicted
mortality in hospitalized heart failure patients at 30 days and
one year," says a report in the Nov. 19 Journal of the American
Medical Association by a team at the University of Toronto.
The model fills a gap in medical
practice, says study leader Dr. Douglas S. Lee.
"Up to this point in time, there
have been essentially no methods for clinicians to measure the
prognosis for heart failure patients in the real world," Lee says.
"Evidence from clinical trails has been useful, but participants
in those trials tend to be different from the patients we see
in everyday life. They generally are younger, in better health,
and with fewer co-morbid conditions."
Lee and his colleagues collected
comprehensive data on more than 4,000 patients admitted to hospitals
in the province of Ontario between 1997 and 2001 for heart failure,
a progressive loss of the ability of the heart to pump blood.
Heart failure is known to be a
warning sign of trouble ahead. Previous studies have found a one-year
death rate in heart failure patients in the neighborhood of 40
percent. The Toronto researchers say they were able to assess
the risk of individual patients by measuring factors such as blood
pressure, respiratory rate, and blood levels of sodium and urea
nitrogen, and by including other medical problems, formally known
as co-morbid conditions -- lung disease, dementia such as Alzheimer's
disease, cirrhosis of the liver, and so on.
Following the patients after their
hospital admissions, the Toronto researchers were able to identify
the factors that predicted the risk of death. "The strongest predictors
were kidney function, blood pressure and age," Lee says.
There was a striking difference
between patients facing the highest and lowest risk, he says.
"The mortality rate in the highest-risk group at one year was
79 percent," Lee says. "In the lowest-risk group it was 7 percent,
a tenfold difference."
"We hope that the data from this
study can be used to identify patients who may need closer monitoring
and more aggressive intervention," he says. "A patient admitted
with heart failure in the high-risk category potentially could
be admitted to a monitored or intensive care setting, rather than
a hospital ward. And future research may show whether intervention
in the high-risk group can lower their risk."
It's hoped that other doctors will
pick up the study and extend its results. "We're interested in
what kind of feedback we get," Lee says.
The reaction of Dr. Richard B.
Devereux, professor of medicine at Weill Medical College of Columbia
University, is that the study "is the right way to develop a predictive
model."
"It is a very nice job of looking
at a number of things that are individually well known to be associated
with risk and producing a comprehensive model," Devereux says.
"This is very nice medical science."
It's a model that can be put to
work without much difficulty, Devereux says: "Something that can
be easily put into a computer to see how well it predicts outcome
in other populations."
Devereux is co-author of a paper
in the November issue of the American Journal of Hypertension
about a warning sign of danger in people with high blood pressure.
An analysis of studies of more than 1,000 patients shows that
enlargement of the left ventricle, the main pumping chamber of
the heart, signals that aggressive treatment is needed to reduce
the risk of heart attack, stroke and other cardiovascular problems,
the report says.
"Left ventricular hypertrophy has
long been known as an indicator of risk," Devereux says. "What
has not been known before is that reversing it is beneficial to
patients."
No special treatment is needed
to reverse the enlargement and bring the heart muscle back to
normal, he says, just greater attention to the standard methods
of controlling blood pressure, such as medication and weight loss
for obese people. "All blood pressure lowering treatments have
beneficial effects," he says.
More information
An overview of heart failure can
be found at the American
Heart Association and MedlinePlus.
Reference
Source 101
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