Original articleCombined exercise and cognitive behavioral therapy improves outcomes in patients with heart failure
Introduction
Depression is increasingly recognized as a strong predictor of health status and poor clinical outcomes in patients with heart failure (HF) [1], [2]. Patients with HF have two to three times higher rates of depression than the general population and twice the rate of most other chronic medical illnesses [3], [4]. Major depression is estimated to occur in approximately 25% of HF patients; another 30% to 35% experience minor depression. Depressed HF patients experience a more rapid loss of physical function and onset of physical disability [5], [6], [7], [8], greater symptom severity, poorer health-related quality of life (HRQOL), more frequent hospitalizations, and higher mortality rates than nondepressed HF patients [9], [10], [11], [12]. Despite the deleterious consequences of depression in patients with HF, there are surprisingly few trials of treating depression in cardiovascular disease that has specifically targeted this population.
Depression increases both in prevalence and severity as HF worsens. For example, in a recent meta-analysis, Rutledge [13] reported that the rates of depression continued to increase nearly 10% per New York Heart Association (NYHA) class (11% NYHA Class I up to 42% in NYHA Class IV), or a four-fold difference between Class I (asymptomatic) and Class IV (symptomatic at rest) patients. Numerous reports also suggest that depression increases morbidity and mortality in HF patients, independent of traditional cardiovascular risk factors [e.g., smoking, hypertension, low left ventricular ejection fraction (LVEF), high cholesterol and obesity] [2], [13], [14], [15]. Similar underlying physiological mechanisms including hypothalamic pituitary axis, sympathoadrenal medullary, and immune responses are activated, bidirectionally and additively, when both HF and depression are present [2], [13]. It is through these physiological pathways and behavioral mechanisms (sedentary, nonadherence, unhealthy lifestyle) that depression is thought to increase risk for adverse cardiac events and worsen clinical outcomes in HF patients. It is well established that HF patients who are depressed more often fail to adhere to prescribed medical regimens [16] and participate in high-risk behaviors such as smoking and alcohol use [1], [17], [18]; they also use more health care resources [19], [20], [21] and have poorer HRQOL [22], [23], [24], [25] than nondepressed patients.
Considerable evidence supports that depression and physical function are mutually reinforcing and change in the same direction over time; when one worsens, the other also worsens [4]. Patients who are depressed perceive greater symptom severity, poorer physical function, and often curtail physical activity level to avoid worsening exertional intolerance and considerably lower HRQOL in patients with HF. Reduced physical activity enhances the deleterious peripheral and musculoskeletal pathological changes that are known to worsen HF symptom severity and accelerate disease progression [2], [6], [8], [13]. An intervention that concomitantly maximizes physical function and fosters problem-focused coping, therefore, may provide the best opportunity for reducing depression, improving clinical outcomes, and enhancing HRQOL in patients with HF.
Treating depression is especially challenging in patients with HF because they are often older, have multiple comorbidities, and are on complex medication regimens [2], [13], [26]. Antidepressants often do not completely resolve depression in patients with HF, and relapse rates are high [27], [28], [29]. In addition, patients with HF who take antidepressants may be at higher risk for adverse events and hospitalization [26]. Moreover, the largest randomized study conducted to date in patients with HF experiencing depression, the Safety and Efficacy of Sertraline for Depression (SADHART) in Chronic Heart Failure [30], found that nurse-led control visits were as effective as antidepressant therapy for depression. For these reasons, nonpharmacological interventions for depression in HF may be particularly suitable [31], [32]. Nonpharmacological interventions may provide important advantages over antidepressant therapy alone, including fewer drug interactions, greater short-term relief of depressive symptoms, and more involvement of patients in their self-care, but none have been reported in patients with HF [31], [32], [33], [34].
Cognitive behavioral therapy (CBT) incorporates techniques such as self-monitoring, problem solving, and mutual goal setting that reinforce the benefits of exercise (EX) as well as other essential self-care strategies that improve clinical outcomes in patients with HF [35], [36]. Coping skills can be taught using CBT strategies that attend to the physical and functional changes and consequences of HF, promote a positive health attitude, and facilitate adaptation, reducing the psychological burden [33], [34], [35], [36], [37]. Exercise holds promise for improving outcomes in HF, yet EX alone has not been shown to change the distorted thought patterns and negative perceptions that contribute to maladaptive coping in depressed HF patients. Exercise is known to partially reverse the underlying skeletal muscle changes that contribute to worsening HF and symptom severity [38], [39], [40], [41], [42], [43], [44], [45], [46] and has also been shown to increase physical function and improve HRQOL in a number of studies, but it has not been specifically used to alleviate depression in patients with HF [13].
The purpose of this randomized, controlled, repeated measures study was to compare the efficacy of three interventions (a combined 12-week home-based EX/CBT program, CBT alone, and EX alone with usual care (UC) in stable, NYHA II to III HF patients with minor or major depression at baseline (BL) according to Diagnostic and Statistical Manual-IV (DSM-IV) criteria [47]. We hypothesized that patients in the combined EX/CBT group would have a greater reduction in depression severity and better physical function and HRQOL compared to the other groups at 12 and 24 weeks.
Section snippets
Methods
Men and women between the ages of 30 and 70 who were an outpatient in an HF clinic in Northeast Georgia with a documented diagnosis of NYHA Class II to III heart failure and a Beck Depression Inventory II (BDI-II) [48] score of 10 or higher were asked to participate in the study. Participant inclusion criteria included (a) documented medical diagnosis of HF; (b) LVEF of ≥15% documented within the last year by echocardiogram, cardiac catheterization ventriculography, or radionuclide
Depression outcome
Examining the results for the entire participant pool, there were declines in HAM-D scores over 5 time points (BL, 4, 8, 12, and 24 weeks) in all four groups (Fig. 2), but none were statistically significant. Notably, when compared to the other groups, only the combined EX/CBT group had a sustained reduction in depression at 12 and 24 weeks. However, data analysis revealed that when participants were dichotomized as having minor depression (HAM-D scores between 11 and 14) or moderate-to-major
Discussion
The combined EX/CBT group was the only group that showed sustained improvement on all primary outcome variables at 12 and 24 weeks, and that the intervention effects were stronger in patients with moderate-to-major depression (HAM-D 15 or higher). All patients who had minor depression (HAM-D, 11–14) improved over time despite group assignment, indicating that intervention may not be necessary in these patients. Because 40% of our patients had minor depression and the small sample size in each
Acknowledgments
Funding for the study was provided by the Southeast Affiliate of the American Heart Association Beginning Grant-in-Aid, Atlanta Clinical and Translational Science Institute at Emory University School of Medicine.
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