Published: Aug. 12, 2001
Updated: Nov. 3, 2004
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By Duke Medicine News and Communications
DURHAM, N.C. -- Duke University Medical Center researchers have found that congestive heart failure patients with major depression appear twice as likely than those who are not depressed to die or be re-admitted to the hospital within 12 months.
Since up to half of patients with clinically significant heart failure die within five years of diagnosis -- a rate that has not improved significantly over the years despite improvements in treatments -- the Duke researchers recommend that all congestive heart failure (CHF) patients be tested for the presence of major depression.
"Heart failure is a deadly disease, and now we know that those patients who are suffering from major depression are at a much greater risk of death," said Duke researcher Dr. Wei Jiang, who published the results of her study Monday (Aug. 13) in the journal Archives of Internal Medicine. The study was supported by grants from the National Institutes of Health and the Claude D. Pepper Older Americans Independence Centers.
Dr. Christopher O'Connor, Duke cardiologist, and Dr. Ranga Krishnan, chairman of Duke's Department of Psychiatry, were senior mentors for the research team.
"If more cardiologists considered the impact of depression on their heart failure patients and treated the depression, the outcomes for these patients may improve," she continued. "Given what we know about depression and heart disease in general, psychiatric screening should be a part of all cardiac workups."
When compared to CHF patients without depression, the patients with major depression in the Duke study died at a 2.5-times higher rate three months after admission, and 2.23-times higher rate one year later. As for hospital re-admissions, the patients with major depression returned at a 1.9-times higher rate at three months, and a 3.07-times higher rate at one year.
The researchers controlled for such factors as age and severity of heart disease, and found that major depression was an independent risk factor for increased death and re-admission.
While the link between depression and worse outcomes for patients with coronary artery disease has been firmly established, Jiang said that very few studies have looked for an association with CHF, which isn't so much a single disease, but a constellation of conditions with many underlying causes. The end result is that the quantity of blood pumped by the heart each minute is insufficient to meet the body's normal requirements for oxygen and nutrients.
The Duke researchers screened consecutive CHF patients admitted to Duke University Hospital during a 15-month period and found that of the 357 patients screened, 35.3 percent had some symptoms of depression, with 13.9 percent of those diagnosed with major depression.
Specifically, CHF patients who weren't depressed had mortality rates of 5.7 percent at three months and 13.7 percent at one year. However, for those with major depression, the death rates jumped to 13 percent at three months and 26.1 percent at one year.
As for hospital re-admissions, 36.5 percent of the non-depressed patients were re-admitted within three months, and 52.3 percent at one year. For those with major depression, the rates increased to 52.2 percent at three months, and 80.4 percent at one year.
"Obviously, the next step is to see whether treating these patients' depression will have a beneficial outcome on their heart failure," Jiang said. "No studies have yet been conducted to see if strategies for treating depression can help these patients."
That task will be a challenge, Jiang said, because most CHF patients take as many as eight different medications for their disease and current anti-depressive medications can interact with them. Other non-pharmacologic approaches such as cognitive-behavioral therapy or other forms of psychotherapies also need to be considered, she added.
"This article makes an important contribution by showing that patients with congestive heart failure and depression are twice as likely to die within one year after hospitalization as those with congestive heart failure alone," said Dr. Stanley L. Slater, Deputy Associate Director for Geriatrics, National Institute on Aging. "Future research must focus on whether adding treatment for depression to treatment for congestive heart failure will increase survival in patients sufferingfrom both diseases."
Jiang emphasized that major depression is a clinically distinct condition, and not just the expected feelings of sadness a patient may experience as a result of having a serious and potentially life-threatening medical or physical condition.
While it is not known by what mechanism major depression influences heart function, several theories are being considered.
"People with major depression tend to have poor social support networks or perceive their social support insufficient and may not be as compliant with their medications," Jiang said. "Also, some studies have shown an association with depression and higher activity of platelets, which can cause clots in arteries."
More than 2 million Americans have CHF, with 400,000 new cases being diagnosed each year, according to the National Heart, Lung and Blood Institute. Also, treating CHF is the largest single expense for the Medicare system, with more that $7 billion spent annually on more than 1 million admissions.
Duke colleagues involved in the study included Dr. Jude Alexander, Dr. Eric Christopher, Maragatha Kuchibhatia, Laura Gaulden, Dr. Michael Cuffe, Dr. Michael Blazing, Charles Davenport and Dr. Robert Califf.