Inclusion Criteria:  Planned coronary surgery Written informed consent  Exclusion Criteria:  Depression (BDI-II score more than 8) Dementia (MMSE score less than 24; FAB score less than 11; MoCA score less than 20) Life-threatening rhythm disturbances Chronic heart failure (NYHA functional class III and higher) Chronic obstructive pulmonary disease Malignant pathology Drug addiction Stroke Brain injuries