Cross-lagged relations between exercise capacity and psychological distress during cardiac rehabilitation

Background Poorer mental health is associated with lower exercise capacity, above and beyond the effect of other cardiovascular risk factors. However, the directionality of this relationship remains unclear.Purpose The main aim of the present study was to clarify, with a cross-lagged panel design, the relationship between psychological status and exercise capacity among patients in a cardiac rehabilitation (CR) program.Methods A clinical sample of 212 CR patients completed exercise-capacity testing and measures of depression and anxiety (Hospital Anxiety and Depression Scale) pre-CR and post-CR. Demographic and clinical data, including BMI and smoking history, were also collected. Multivariate stepwise regression analysis was performed to identify the best predictors of exercise capacity at discharge. Structural equation modeling was utilized to quantify the cross-lagged effect between exercise capacity and psychological distress.Results Multivariate regression analysis revealed that higher levels of psychological distress pre-CR are predictively associated with less improvement in exercise capacity post-CR, beyond the effects of age, sex, and baseline functional status. Results from structural equation modeling supported a 1-direction association, with psychological distress pre-CR predicting lower exercise capacity post-CR over and above autoregressive effects.Conclusions Study results did not support the hypothesis of a bidirectional relationship between psychological distress and EC. High levels of psychological distress pre-CR appeared to be longitudinally associated with lower exercise capacity post-CR, but not vice versa. This finding highlights the importance of assessing and treating both anxiety and depression in the early phase of secondary prevention programs.