Depression and anxiety in cardiac rehabilitation: differential associations with changes in exercise capacity and quality of life

Background Cardiac rehabilitation (CR) has been successful in improving exercise capacity (EC) and quality of life (QoL). However, depression and anxiety are highly prevalent among cardiac patients and might represent risk factors for rehabilitation outcomes. The aim of this study was to investigate the role of depression and anxiety as possible independent risk factors for CR outcomes. Methods The study applied a pre-post-design. The sample comprised N = 3'434 cardiac disease patients taking part in a Swiss inpatient CR center. Variables measured at the beginning (T1) and end of rehabilitation (T2) included depression and anxiety (HADS), EC, and QoL (MacNew). A path analysis was conducted. Results Depression at T1 had a significant negative relationship with improvements in EC and in all aspects of QoL during rehabilitation. Anxiety at T1 was positively related to improvements in EC and in emotional and physical QoL. Improvements in depression during CR were positively related with improvements in all outcomes. Improvements in anxiety showed no significant association with the outcomes. Conclusion Depression and anxiety should be screened for during CR. Depression should be treated due to the negative association found with rehabilitation outcomes. Underlying mechanisms of the positive association of anxiety with rehabilitation outcomes need further investigation.