Patients with heart disease who are depressed are more likely to smoke, not exercise and not take heart medications correctly than those who are not depressed, thereby putting themselves at greater risk for stroke, heart attack, heart failure, and death, according to a five-year study of over one thousand heart patients led by a researcher at the San Francisco VA Medical Center.
The study, which appears in the November 26, 2008 issue of the Journal of the American Medical Association, also showed that risk increases with the degree of depression.
“It’s long been known that there’s a link between depression and bad outcomes among people with heart disease, and now we have some idea why,” says lead author Mary Whooley, MD, an SFVAMC staff physician and a professor of medicine at the University of California, San Francisco.
Whooley is principal investigator of the Heart and Soul Study, which followed 1,017 patients with stable coronary heart disease for an average of five years. Over the course of the study, participants who initially reported depressive symptoms were 50 percent more likely to develop cardiovascular events than those without depressive symptoms. A cardiovascular event was defined as a transient ischemic attack (a brief interruption of blood supply to the brain), a stroke, a heart attack, heart failure, or death. Depression was measured using the Patient Health Questionnaire, a standard self-administered checklist of depressive symptoms.
The researchers found that the depressed patients were significantly more likely to smoke and significantly less likely to exercise and comply with medication instructions than patients who were not depressed. They also found that the more depressive symptoms a patient reported, the more likely the patient was to have a cardiovascular event.
Whooley notes that treating depression itself has not been shown to improve health outcomes among heart patients. “This study suggests that helping these patients with their health behaviors might be a better way to go,” says Whooley. “Get them into exercise programs, help them reduce smoking, and help them take their heart medications with better compliance, and then let’s see how they do.”
Whooley says that one drawback of the study is that the causes and effects of inactivity are not clearly delineated: “Depressed patients are exercising less, but less physical activity might cause depression, so it’s hard to know whether depression preceded or succeeded physical inactivity.” However, she says, “it doesn’t matter which came first, because the answer is the same in either case: exercise more, which will reduce the risk of cardiovascular events associated with depression.”
The Heart and Soul Study, which began in 2000 and ended in January 2008, has so far yielded 60 peer-reviewed papers on a variety of topics related to heart disease, according to Whooley. “In designing the study, I knew it would be used to investigate research questions that I didn’t anticipate, and so we collected a large amount of baseline and ongoing data very carefully,” she says. “But I really didn’t expect this rate of publication, which is due to the work of the amazing residents and fellows here at SFVAMC.”
Coauthors of the paper are Peter de Jonge, PhD, of the University of Gronigen and Tilburg University, the Netherlands; Eric Vittinghoff, PhD, and Mitchell D. Feldman, MD, MPhil, of UCSF; Christian Otte, MD, of University Hospital Hamburg-Eppendorf, Germany; Rudolf Moos, PhD, of Palo Alto VA Health Care System and Stanford University; Robert M. Carney, PhD, of Washington University, St. Louis; Sadia Ali, MD, MPH, Sunaina Dowray, MPH, and Beeya Na, MPH, of SFVAMC; Nelson B. Schiller, MD, of SFVAMC and UCSF; and Warren S. Browner, MD, MPH, of UCSF and California Pacific Medical Center, San Francisco.
The study was supported by the Department of Veterans Affairs, the National Heart, Lung, and Blood Institute, the American Federation for Aging Research, the Robert Wood Johnson Foundation, the Ischemia Research and Education Foundation, and the Nancy Kirwan Heart Research Fund. Some of the funds were administered by the Northern California Institute for Research and Education.
NCIRE - the Veterans Health Research Institute - is the largest research institute associated with a VA medical center. Its mission is to improve the health and well-being of veterans and the general public by supporting a world-class biomedical research program conducted by the UCSF faculty at SFVAMC.
SFVAMC has the largest medical research program in the national VA system, with more than 200 research scientists, all of whom are faculty members at UCSF.
UCSF is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care.