Even Mild Depression Increases Long-Term Mortality in Heart Failure
DURHAM, N.C. – Duke University Medical Center researchers
have found a strong association between depression and a higher
long-term risk of death for patients with chronic heart
Additionally, and just as importantly, the researchers said
even a psychological status previously considered to be
sub-depressive puts these patients at higher risk of death.
While it has been known that depression is associated with
higher short-term mortality rates, this is the first study to
measure the long-term risks of depression, they said.
The researchers, led by medical psychiatrist Wei Jiang,
M.D., believe that their findings should help convince
physicians who care for heart failure patients to pay close
attention to their patients' psycho-social status, since these
patients may be helped by aggressive heart failure and/or
Jiang presented the results of her study March 7, 2005, at
the annual scientific sessions of the American College of
Cardiology in Orlando. The study was supported by the National
Institute of Mental Health.
"Our findings provide further evidence to non-psychiatric
physicians that depression can have a major impact on how their
patients fare," Jiang said. "Approximately half of all patients
with heart failure will die within five years of diagnosis, and
we believe that our study appears to identify a group of these
patients who are at a higher risk for dying."
Heart failure is a condition marked by the inability of the
heart muscles to pump enough oxygen and nutrients in the blood
to the body's tissues. Also known as congestive heart failure,
its many causes include infections of the heart, coronary
artery disease, high blood pressure, previous heart attacks and
valve problems. An estimated 4.7 million Americans suffer from
the condition, with 400,000 new cases reported each year, and
according to the researchers, it is the only cardiovascular
disease that is rising in incidence.
The condition often leaves patients exhausted and
breathless, severely restricting the normal activities of
everyday life. Although there is no cure, a variety of drugs
are often used to improve the strength of the heartbeat
(digoxin), to relax blood vessels (ACE inhibitors), or to
remove the excess buildup of fluid in the lungs
The Duke team followed 1,005 heart failure patients admitted
to Duke University Hospital for various cardiac events. During
their hospitalization, patients were given the Beck's
Depression Inventory (BDI), a commonly used depression
screening test. Patients were followed for seven years to
determine the ability of BDI scores to predict death.
In general, patients with a BDI score of 10 are considered
mildly depressed, while patients with scores of 12 to 19 can be
considered mild to moderately depressed. Jiang said that the
traditional cutoff value of BDI for assessing the prognostic
predictability was a score of 10.
"In our group of patients, those who had a score of 10 or
higher had a 44 percent greater risk of dying," Jiang said.
"However, the greatest risk occurred when we lowered the
threshold to a score of eight or greater. In our study,
patients scoring seven or higher had a 51 percent higher risk
"This adverse association of depression and increased
long-term mortality was independent of other factors, including
age, marriage, cardiac function and the root cause of the heart
failure," Jiang said.
Jiang said that many cardiologists or primary care
physicians who treat heart failure patients may be unfamiliar
with, or too busy to include, a psychological assessment into
their practice. However, she pointed out, tests like the BDI do
not require special training and can be completed in 10
minutes. Patients respond to 21 sets of questions with a number
ranging from 0 to three.
For example, one such graded question set is: "I don't feel
disappointed in myself – 0;" "I am disappointed in myself – 1;"
I am disgusted with myself – 2;" or "I hate myself – 3."
"As you can see, it would not be difficult to get a score of
eight or greater, pointing out how important it is to identify
patients with depressive symptoms early and provide the
appropriate treatment or support," Jiang said.
While this and other studies have demonstrated links between
depression and worse outcomes for patients with cardiovascular
disease, the mechanisms behind the correlation are not well
understood, Jiang said. It is known that depressed patients
have altered blood platelet aggregation properties, elevated
immune-inflammatory responses and a decrease in the heart's
ability to react appropriately to the stresses of everyday
life, she said.
"We also know that depressed patients tend not to comply
with their treatments, are not as motivated to stick with
exercise or rehabilitation programs, and often miss doctor's
appointments" Jiang said. "Also, depressed patients tend to
make unhealthy life-style choices in such areas as diet and
While anxiety is often present with depression, previous
studies by Jiang have shown that depression appears to be the
main risk factor for these patients. In the Nov.
30 issue of the journal Circulation, Jiang found that while
anxiety and depression are highly correlated in heart failure
patients, depression alone predicts a significantly worse
progrnosis after one year.
Jiang is currently investigating whether the use of
anti-depressant medication has an effect on the outcomes of
depressed heart failure patients.
Joining Jiang in the study were Duke colleagues Maragatha
Kuchibhatla, Ph.D., Michael Cuffe, M.D.; Greg Clary, M.D., Eric
Christopher, M.D., Jude Alexander, M.D., Ranga Krishnan, M.D.,
and Christopher O'Connor, M.D.