Thus, 6MWD< 290 m had a good prognostic value of mortality and re-hospitalization for patients with chronic heart failure with EF < 40%. The 6-minute walk test had a better predictive value in mortality and rehospitalization in patients with HFrEF compared to left ventricular diastolic diameter, left atrial diameter, and plasma NT - proBNP and hs-TroponinT levels.