Living alone, financial difficulties, excessive use of alcohol and poor results on a heart failure questionnaire were associated with the onset of depression among outpatients with heart failure, according to a new study in the Dec. 21, 2004 issue of the Journal of the American College of Cardiology.
“The relationship was so strong that a patient with three out of four of those factors had about a 70 percent chance of having depression a year later,” said Edward P. Havranek, M.D., F.A.C.C., at the University of Colorado Health Sciences Center and Denver Health Medical Center. “Honestly, we were more surprised by what we didn't find than by what we did find. Factors like these predict depression in the general population, but the things that doctors usually use to assess the severity of heart failure, such as exercise tests, echocardiograms, blood tests, did not predict who would become depressed.”
The study, which also included researchers at the Denver Veterans Administration Medical Center, the Mid-America Heart Institute and the University of Missouri in Kansas City, looked at 245 heart failure outpatients who did not have symptoms of depression. At the time of enrollment and again a year later, the participants were given a full clinical evaluation that included social and economic status. They also filled out two questionnaires, the Medical Outcomes Study-Depression questionnaire and the Kansas City Cardiomyopathy Questionnaire, which measures how much a patient feels the disease interferes with daily life.
In multivariable analysis, living alone, alcohol abuse, perception of medical care as being a substantial economic burden and health status as measured by the Kansas City questionnaire were independent predictors of developing depressive symptoms.
In this study, 21 percent of the heart failure patients developed symptoms of depression within a year. However, the rate was almost 70 percent among those with three out of four of the risk factors, compared to less than 8 percent among those patients without any of the risk factors.
Dr. Havranek said these results linking depression with social factors and patients’ perceptions of the burden of disease are at odds with common theories about why heart failure patients may be up to five times as likely to be depressed as are similar individuals who do not have heart failure.
“The reason we were surprised was that most of the theories about how depression develops in heart failure patients are based on physiologic factors, like high levels of stress hormones brought on by heart failure. If these theories were correct, the predictors of depression should have been things like poor exercise test results, low ejection fraction and high levels of heart-failure-related hormones like BNP,” Dr. Havranek said.
B-type Natriuretic Peptide (BNP) is a hormone released from heart ventricles.
Dr. Havranek said the results suggest physicians should systematically screen heart failure patients for depression, particularly those with one or more of the risk factors identified in this study.
“If depression is found and treated, patients may feel better even without an improvement in the status of their heart failure,” he said. “We believe we will be better able to devise an effective treatment strategy if we understand the factors that uniquely contribute to the development of depression in heart failure patients.”
For now, Dr. Havranek suggested doctors monitor alcohol use by patients and pay close attention to patients’ perceptions of disease, not just their medical test results.
He said that further work is needed in order to devise treatments for depression that are tailored specifically for patients with heart failure. He also noted that this study cannot prove cause and effect, for instance, whether alcohol use increases the risk of depression or is a sign that a patient with depression is “self-medicating” with alcohol. However, he pointed out that at the beginning of the study, the patients did not show symptoms of depression.
Martha J. Radford, M.D., F.A.C.C., at Yale University in New Haven, Conn., who was not connected with this study, said the findings of this prospective look at heart failure patients are in line with what doctors tend to see in their clinical experience.
“What this tells practicing physicians is that they need to keep an eye out for depression among their heart failure patients and deal with it if it should occur,” Dr. Radford said.
She said the influence of social factors was bigger than she would have expected.
"The magnitude of it was fairly striking. Just by treating heart failure alone, we're not going to make much of an impact on the incidence of depression among heart failure patients. And that's a message for physicians: they need to address their patients' other needs, as well," she said. "This is what patient-centered care is all about."
The American College of Cardiology, a 31,000-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.