05 Jan Depression Linked To Functional Decline In Heart Disease Patients
Medical Research: What is the background for this study? What are the main findings?
Dr. Sin: Older patients with coronary heart disease often experience declines in functional status, which is the ability to perform daily activities such as bathing, walking, and doing housework. The key factors that contribute to functional status among cardiac patients are not well-understood. Previous studies have found only weak or no associations between cardiovascular disease severity and functional status. Psychological factors—such as depression—are known to increase the risk of functional impairment, but this has not been studied long-term in patients with coronary heart disease.
It is unclear the extent to which long-term functional status is determined by psychological factors versus cardiovascular disease severity. The purpose of our study was to compare the contributions of depressive symptoms with those of cardiovascular disease severity (specifically, left ventricular ejection fraction, exercise capacity, and angina frequency) for predicting subsequent functional decline in 960 older adults with stable coronary heart disease.
Across a 5-year period, people who had more severe depressive symptoms were at greater risk of functional decline, independent of cardiovascular disease severity, demographics, health behaviors, cognitive function, and other factors. Low exercise capacity was also strongly related to future functional decline, but ejection fraction and angina frequency were not. These findings underscore the importance of considering both mental and physical health in determining long-term functional status.
Medical Research: What should clinicians and patients take away from your report?
Dr. Sin: The promotion of functional status is a critical goal of disease management for patients with coronary heart disease. The results of our study suggest that efforts to alleviate depressive symptoms may be as important as treating cardiovascular disease severity for improving and maximizing functional status. Yet, the model of care delivery for patients with both depression and cardiovascular disease in the primary care setting is an important topic that requires additional investigation.
Medical Research: What recommendations do you have for future research as a result of this study?
Response: The mechanisms that link depressive symptoms to subsequent functional status are unclear; more work is needed to understand potential biological pathways, as well as depression-related changes in behaviors and attitudes that may contribute to functional decline. In addition, randomized controlled trials in cardiac patients have produced mixed findings for the effect of depression treatment on functional status and cardiovascular outcomes. Further research should address how best to incorporate depression treatment into the management of coronary heart disease to improve functional status.