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Contact:
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May 7, 2003
Preserved
Ejection Fraction Doesn't Shield Heart Failure Patients from
Heavy Burden
Editorial comment highlights importance
of the names given to types of heart failure.
(BETHESDA,
MD)—Heart failure patients with high ejection fractions
may not have as rosy a prognosis as many believe, according
to a
new study in the May 7, 2003 issue of the Journal
of the American College of Cardiology.
The
study of 413 heart failure patients hospitalized at Yale-New
Haven Hospital in Connecticut showed that even patients with
an ejection fraction of at least 40 percent still faced a
considerable burden, with a substantial risk of death, and
a risk of readmission, disability, and symptoms comparable
to that of heart failure patients with lower ejection fractions.
Most
research on heart failure has focused on patients with depressed
systolic function, that is, they have lost much of their ability
to pump blood out of the heart with each beat. However, up
to half of older heart failure patients have preserved systolic
function, but their hearts have difficulty relaxing and refilling
between beats. Grace L. Smith, MPH, and colleagues at Yale-New
Haven Hospital, Denver Health Medical Center in Denver, Colorado,
and Emory University School of Medicine in Atlanta, Georgia,
wanted to evaluate the common belief that a higher ejection
fraction was associated with better outcomes. The researchers
said this was also the first study to look at quality of life,
functional ability, and the trajectory of disease in this
group of heart failure patients.
"What
was remarkable about the study was that heart failure with
preserved systolic function puts a substantial burden on patients,"
said Harlan M. Krumholz, MD, FACC. "Even though their
survival was relatively better than the patients with depressed
systolic function, the absolute risk of dying was quite high.
In addition, when you looked at other outcomes that are important
to patients, such as how they function and how they feel,
you see that in fact the outcomes for those with preserved
systolic function were just as bad as those with depressed
systolic function."
After
six months, 13 percent of patients with preserved ejection
fraction had died, compared with 21 percent of patients with
depressed ejection fraction (p = 0.02). However, the rates
of functional decline were similar among those with preserved
and depressed ejection fraction (30 percent vs. 23 percent,
respectively; p = 0.14). After adjusting for demographic and
clinical factors, preserved ejection fraction was associated
with a lower risk of death (hazard ratio [HR] 0.49, 95% confidence
interval [CI] 0.26 to 0.90; p = 0.02), but there was no difference
in the risk of readmission (HR 1.01, 95% CI 0.72 to 1.43;
p = 0.96) or the odds of functional decline or death (OR 1.01,
95% CI 0.59 to 1.72; p = 0.97).
"The
message here is that heart failure is a harbinger of poor
outcome whether or not someone has preserved systolic function,"
Dr. Krumholz said. "The study highlights the urgent need
for research to prevent and treat heart failure with preserved
systolic function. Our study suggests that these patients
incur quite a burden from their disease, even if their hearts
are squeezing well."
Dr.
Krumholz said that while the findings may also offer clues
to possible outcomes for heart failure patients living in
the community, the ability to generalize those findings to
that larger group of patients needs to be tested, since this
study involved only patients who had been hospitalized for
heart failure.
In
an editorial comment in the
journal, Michael R. Zile, MD at the Medical University of
South Carolina in Charleston argued that the name given to
types of heart failure can influence the direction and progress
of medical research. While the Yale study classified patients
as having either preserved or depressed ejection fraction,
Dr. Zile said he prefers terms that identify the underlying
dysfunction, so that patients with preserved ejection fractions
would be said to have diastolic heart failure, as opposed
to systolic heart failure.
"What
I tried to do in the editorial is build a case for why you
should call it diastolic heart failure. What I did in the
editorial is to say, 'What is diastolic heart failure? What
measurements of diastolic function can be used? What diagnostic
criteria can be used?' And I tried to make the point that
while all patients with heart failure have abnormalities in
both systole and diastole; the real question is which one
of those pathophysiologies predominates in which group of
patients," Dr. Zile said.
Dr.
Zile said he believes the debate over terminology and confusion
about measurement and definitions of patient groups is one
reason that there have been relatively few major drug trials
in these heart failure patients.
"It's
taken a very, very long time to get the pharmaceutical industry
interested in doing these trials. And I think one of the reasons
is because of this controversy. Choosing simple pathophysiologically-based
terminology that provides a rationale for existing differences
in treatment focuses research aimed at developing more specific
treatment targets and promotes sponsorship of randomized clinical
trials," Dr. Zile said.
Dr.
Krumholz said that although he agrees patients with preserved
ejection fraction probably have diastolic heart failure, his
research team measured only ejection fractions, not diastolic
heart function, so they felt it was more precise to use the
ejection fraction terminology.
The
American College of Cardiology, a 28,000-member nonprofit
professional medical society and teaching institution, is
dedicated to fostering optimal cardiovascular care and disease
prevention through professional education, promotion of research,
leadership in the development of standards and guidelines,
and the formulation of health care policy.
The
American College of Cardiology (ACC) provides these new reports of clinical studies
published in the Journal
of the American College of Cardiology as a service to physicians, the media,
the public, and other interested parties. However, statements or opinions expressed
in these reports reflect the view of the author(s) and do not represent official
policy of the ACC unless stated so.
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