Physical activity after myocardial infarction: is it related to mental health?

BACKGROUND: Physical inactivity and poor mental wellbeing are associated with poorer prognoses in patients with cardiovascular disease. We aimed to analyse the cross-sectional and prospective associations between physical activity and mental wellbeing in patients with a history of myocardial infarction. DESIGN: Longitudinal, observational study. METHODS: We investigated 600 older subjects with a history of myocardial infarction (age range 60-80 years) who participated in the Alpha Omega Trial (AOT). They were tested twice at baseline and at 40 months follow-up for physical activity - with the Physical Activity Scale for the Elderly (PASE); depressive symptoms - with the Geriatric Depression Scale (GDS-15); and dispositional optimism - with the Life Orientation Test (LOT-R). Linear (multilevel) and logistic regression analyses were used to examine cross-sectional and longitudinal associations. RESULTS: Physical activity was cross-sectionally associated with depressive symptoms (adjusted beta = -0.143; p = 0.001), but not with dispositional optimism (adjusted beta = 0.074; p = 0.07). We found a synchrony of change between physical activity and depressive symptoms (adjusted beta = -0.155; p < 0.001), but not with dispositional optimism (adjusted beta = 0.049; p = 0.24). Baseline physical activity did not predict depressive symptoms at 40 months follow-up. CONCLUSIONS: Concordant inverse associations were observed for (changes) in physical activity and depressive symptoms. Physical activity did not predict depressive symptoms or low optimism.