Coronary heart disease (CHD) is the leading cause of death in the United States; more than 600,000 Americans suffer a fatal cardiac event each year. Traditional CHD risk factors such as high blood pressure, smoking, and elevated cholesterol do not fully account for the timing and occurrence of CHD events. The term "cardiovascular vulnerable patient" has been used to describe patients susceptible to acute coronary events based upon plaque, blood, or myocardial characteristics. Psychosocial factors also have been shown to be associated with increased adverse health outcomes and increased cardiovascular vulnerability. For example, clinical depression and elevated depressive symptoms are associated with increased morbidity and mortality, and as a result, the American Heart Association has recommended that clinicians should routinely assess depression in CHD patients. Although much research and clinical recommendations have focused on depression, the significance of anxiety has been largely ignored, despite the fact that anxiety disorders are as prevalent as depression in the general population and are associated with similar levels of disability.
Despite the prevalence and prognostic significance of anxiety in CHD populations, there have been few randomized clinical trials (RCTs) specifically targeting anxious CHD patients. Anxiolytic medications, including selective serotonin reuptake inhibitors (SSRIs), have been shown to be effective in treating anxiety. SSRIs have been evaluated for the treatment of clinical depression in cardiac patients, with equivocal results. Surprisingly, to our knowledge, there have been no RCTs examining the efficacy of medications for treating anxiety in CHD patients. Moreover, because many cardiac patients are reluctant to take additional medications and psychotropic medications may not be effective for everyone or may produce unwanted side effects, there continue to be a need to identify alternative approaches for treating anxiety in cardiac patients. The investigators believe that exercise may be one such approach.
The purpose of this study is to evaluate the following hypotheses in a population of CHD patients with elevated symptoms of anxiety. The present study will examine the impact of a 3-month intervention of either exercise, Lexapro, or placebo on anxiety symptoms and CHD biomarkers among individuals with cardiac disease and elevated anxiety. The investigators hypothesize that: (1) Both exercise training and medication will reduce anxiety symptoms to a greater extent than placebo; (2) Exercise training will improve CHD biomarkers of risk including autonomic regulation, vascular endothelial function, and inflammation more than either medication or placebo; and (3) Improvements in CHD biomarkers will be mediated by reductions in symptoms of anxiety. The investigators also will explore potential moderators of treatment (e.g., anxiety diagnoses, CHD severity) as well as the longer-term benefits of treatment by documenting medical events and health care costs over a follow-up period of up to 4 years.
