Depressive symptoms as a sex-specific predictor of physical performance development in cardiac rehabilitation

Background Mental health including depression and anxiety can affect the prognosis after cardiovascular events, and sex-specific differences in psychological distress during rehabilitation have been described. However, the extent to which sex-specific psychological factors can predict individual performance development during rehabilitation remains insufficiently investigated. Here, we examined the relationship between mental health and changes in physical performance capacity in men and women during cardiac rehabilitation. Methods Within a prospective, longitudinal study, women and men with coronary artery disease attending cardiac rehabilitation were enrolled. At two time points (T0, admission; T1, discharge), validated questionnaires were used: the Patient Health Questionnaire (PHQ-9) for depressive symptoms (clinical significance ≥10), the Generalized Anxiety Disorder Scale (GAD-7; clinical significance ≥10), and the Hospital Anxiety and Depression Scale (HADS-A; clinical significance ≥11). To assess cardiorespiratory fitness, all patients completed cardiopulmonary exercise testing (CPET) at T0 and T1 and the relative maximum oxygen uptake (VO2/kg) was analyzed as the primary performance parameter. Results 477 patients with complete CPET were included (male: n=361, age: 55.2±7.1 years; female: n=116, age: 55.7±7.5 years). At rehabilitation start, sex differences were observed in depressive symptoms (PHQ-9: 6.2±4.3 [men]; vs. 9.1±5.4 [women]), anxiety symptoms (GAD-7: 5.7±4.2 vs. 8.4±4.9), and anxiety tendency (HADS-A: 6.1±3.9 vs. 8.1±4.4 (all p<0.001). During rehabilitation, men and women showed comparable reductions in anxiety tendency (HADS-A: -1.0±3.0 vs. -1.3±3.9; p=0.510), while female patients showed significantly greater reductions in depressive symptoms (PHQ-9: -2.2±3.1 vs. -3.4±3.6; p=0.024) and anxiety symptoms (GAD-7: -2.2±3.5 vs. -4.4±2.2; p=0.001). Regarding improvement in physical fitness, psychologically affected female patients showed the smallest increase (WomenPHQ≥10: 0.0±2.2 ml/min/kg, pANOVA =0.0486). Male patients showed increased performance capacity regardless of psychological abnormality (+1.3±2.4 [MenPHQ≥10] vs. 1.4±2.6 ml/min/kg [MenPHQ<10]; p=0.708). Conclusion Our results confirm that psychological distress is more frequent and more pronounced in women undergoing cardiac rehabilitation than in men. Despite generally comparable and sex-independent performance gains and psychological improvements during rehabilitation, psychologically affected female patients showed limitations in improving physical fitness. Whether elevated psychological distress impairs training and recovery capacity, particularly in female rehabilitation patients, for example through psychoneuroimmunological mechanisms, requires further investigation. Overall, our findings underscore the importance of cardiopsychological care as part of cardiac rehabilitation, particularly for female patients with elevated psychological distress.