According to background information in the article, "An estimated 5 million people in the United Stated have heart failure, and more than 500,000 new cases are diagnosed annually."
Clinical depression often exists with other illnesses. It affects 40 percent of patients with heart failure with about 75 percent reporting elevated depressive symptoms. In many cardiac patients, depression is associated with worse clinical outcomes.
The authors said:
"Some evidence suggests that aerobic exercise may reduce depressive symptoms, but to our knowledge the effects of exercise on depression in patients with heart failure have not been evaluated."
The research was conducted by James A. Blumenthal, Ph.D., of Duke University Medical Center, and colleagues in order to assess the effects of exercise on symptoms of depression and to decide whether reduced symptoms had an impact on improved clinical outcomes.
2,322 stable patients that were being treated for heart failure at 82 different medical centers in the U.S., Canada, and France participated in the randomized control trial. The experts measured the patients' depressive symptoms by a questionnaire (Beck Depression Inventory II- BDI-II). The range of depressive scores was 0-59; scores of 14 or higher are thought of as clinically significant. The patients were chosen randomly to receive either supervised aerobic exercise (goal of 90 min/week for months 1-3 followed by home exercise with a goal of greater than or equal to 120 min/week for months 4-12) or to education and usual guideline-based heart failure care.
The median BDI-II score at the beginning of the study was 8; 28 percent of the sample had BDI-II scores of 14 or higher. All 2,322 patients had depression scores available at study entry, 2019 at the third month and 1,738 at the twelfth month. Observations showed that the adjusted 3-month BDI-II average score was 8.95 for the exercise group and 9.70 for usual care (a -.76 difference). At the twelfth month, the adjusted BDI-II score was 8.86 for the exercise group and 9.54 for usual guideline-based care (a -.68 difference).
While observing the subset of participants with clinically significant depressive symptoms, the researchers saw similar results (baseline BDI-II scores >14), with BDI-11 scores at the third and twelfth months lower for patients who participated in the aerobic exercise than for those in usual care group.
The participants that were placed in the aerobic exercise group reported greater adherence to the exercise prescription and achieved larger reductions in depressive symptoms, even though the absolute reduction was small.
Results also showed that elevated depressive symptoms were associated with more than a 20 percent increase in risk for hospitalizations and all-cause mortality. This increased risk was separate from antidepressant use and introduced risk factors in patients with heart failure, such as the patient's age and the severity of the disease.
Written by Sarah Glynn