Anemia Linked To Heart Failure Complications
Low hemoglobin levels are a predictor
of increased risk of death and complications
among heart failure patients, according
to a report in Circulation: Journal of
the American Heart Association .
Hemoglobin
(Hgb) is the major substance in red blood
cells, and its level indicates the blood’s
ability to carry
oxygen throughout the body.
“If
you are a heart failure patient and your
hemoglobin drops, then you are at a greater
risk of having problems," says Dr. Inder
S. Anand, the study’s lead author,
and professor of medicine at the University
of Minnesota Medical School and director
of the Heart Failure Program, VA Medical
Center, Minneapolis, Minn.
"What
remains unclear, however, is the ideal
level of hemoglobin to be achieved in
patients with heart failure,” he
says.
Researchers
say one of the causes of anemia may be
related to iron deficiency in heart failure
patients because of malabsorption, nutritional
deficiencies, and impaired metabolism.
Excess
fluid retention may also contribute to
anemia in heart failure patients.
Researchers
do not know if anemia worsens heart failure
or if it is a marker of heart failure
severity, or what effect raising hemoglobin
will have on the heart’s function.
“It
is important to pursue hemoglobin’s
role in the risk of death and complications
in heart failure patients,” Dr.
Anand says.
“The
lifetime risk for developing heart failure
for men and women at age 40 is one in
five," he says. "If 30 percent to 60 percent
of these people are at higher risk for
death and complications because of low
hemoglobin, we might have an opportunity
to treat these patients.
“Treatment
for anemia is relatively simple, with
iron supplements, multivitamins, or drugs,"
Dr. Anand notes. "However, we do not yet
know if treatment is the best strategy
and what the goals of treatment should
be.”
Studies
have shown that low hemoglobin, which
may result in anemia, is more common among
patients with heart failure than it is
among people in the general population.
As many as 25 percent to 60 percent of
heart failure patients have anemia, defined
as hemoglobin less than 12 grams/deciliter
(g/dL) in women and 13g/dL in men.
“Studies
have shown that if you have anemia and
heart failure, your risk of death and
complications [is] increased appreciably
- with as much as 30 percent to 60 percent
additional risk of death and hospitalization
from heart failure,” says Dr. Anand.
To
study the association between anemia and
mortality risk, the researchers used a
database on 5,002 patients enrolled in
the Valsartan Heart Failure Trial, a study
evaluating the high blood pressure medication
valsartan.
At
the beginning of the study, researchers
took a complete blood cell count, and
repeated these measurements at regular
intervals up to 24 months. Of the patients
enrolled in the heart failure study, 23
percent were anemic. Anemic patients tended
to be older, have diabetes, and to have
worse heart failure.
The
researchers found that the group of patients
with the largest average decreases in
Hgb over 12 months (defined as an average
decrease of 1.6 g/dL, from 14.2 to 12.6
g/dL) experienced 47 percent more hospitalizations
and 60 percent more deaths, compared to
those in the group that exhibited an insignificant
(0.10 g/dL) change in hemoglobin during
12 months.
The
researchers report that an increase in
Hgb was associated with a 22 percent lower
death rate in patients with anemia, compared
to 21 percent without anemia, at the start
of the study.
Patients
who had anemia at the start of the study
or whose Hgb decreased during the study
had worse heart failure and an associated
elevation of several other risk factors
for heart disease.
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American
College of Cardiology
American
Heart Association
Centers
for Disease Control and Prevention (CDC)
Circulation:
Journal of the American Heart Association
Go
Red for Women Campaign, AHA
National
Heart, Lung, and Blood Institute (NHLBI)
National
Institutes of Health (NIH)
National
Library of Medicine
National
Women's Health Information Center
Stroke:
Journal of the American Heart Association
US
Health and Human Services |
Persons with prehypertension are at much
higher risk of heart attack and heart
disease, according to a study published
in Stroke: Journal of the American Heart
Association .
“If
we were to eliminate prehypertension,
we could potentially prevent about 47
percent of all heart attacks,” says
the study’s lead author Dr. Adnan
I. Qureshi, professor and director of
the Cerebrovascular Program in the Zeenat
Qureshi Stroke Research Center at the
University of Medicine and Dentistry of
New Jersey.
Normal
blood pressure is defined as lower than
120/80 millimeters of mercury (mm Hg).
Prehypertension
is defined as systolic blood pressure
between 120 and 139 and/or diastolic pressure
between 80 and 89 mm Hg.
Systolic
pressure is the force in the arteries
when the heart beats and diastolic pressure
is the force when the heart is at rest.
About
59 million people in the United States
are prehypertensive.
Hypertension
is defined as blood pressure 140/90 mm
Hg or higher.
“There
is a gray zone, where you are not hypertensive
but your blood pressure is not normal
either,” Dr. Qureshi says.
More
than a year ago, a national committee
coined the term “prehypertension”
for this gray area.
But
until this study, Dr. Qureshi notes, physicians
and the public knew little about what
this term meant.
Researchers
examined existing data from the Framingham
Study and found that a prehypertensive
person is more than three times more likely
to have a heart attack and 1.7 times more
likely to have heart disease than a person
with normal blood pressure.
They
did not find a significantly increased
risk of stroke among those with prehypertension.
“This
is somewhat surprising, but it may be
related to the small number of stroke
events in the study,” Dr. Qureshi
says.
“The
differential effect in this gray zone
may be mediated through factors other
than blood pressure, such as insulin resistance,”
he says.
“While
we classically recommend lifestyle modifications
such as weight control, regular physical
activity, and changes in diet for people
with prehypertension, these findings raise
the question of whether we should treat
prehypertensive patients more aggressively.
Always consult your physician for more
information.
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