Depression is common among patients with heart failure and has a profound effect on their overall cardiovascular health. Scientists have theorized that depression leads to chemical and physical changes in the body that affect the function of the heart.
Although previous studies have linked depression as a whole to worsening symptoms in heart failure patients, the Duke study is the first to detail how fluctuating depression symptoms, even mild ones, impact a patient's outcome.
The Duke University Medical Center research team evaluated the emotional and physical health of 147 patients with heart failure. The patients completed a depression screening questionnaire, called the Beck Depression Inventory (BDI), at the beginning of the study and again one year later. The BDI is a 21-question, multiple choice, self-reporting exam that helps determine the severity of depression symptoms. BDI scores range from 0 to 63. A score of 10 to 16 suggests mild depression; 17-20 suggests moderate depression; 30-63 suggests severe depression.
An increase in the BDI score over time suggests that a patient's depression may be getting worse.
Among the findings:
- Heart failure patients with a 3-point or greater increase in BDI score after one year from baseline, indicating worsening of depression symptoms, were more than twice as likely to die or be hospitalized because of cardiovascular problems during a median follow-up period of five years, compared to those whose depression did not get worse.
- Even mild changes in depression symptoms affect heart failure outcomes. For each point increase in the BDI score over a one-year period, a patient's risk of having a cardiovascular event during follow-up increased by 7%.
Routine screening for depression in patients with heart failure may help doctors develop better treatment and disease management plans, the researchers say.
The findings will be published in the Jan. 25 issue of the Journal of the American College of Cardiology.