Effect of Cardiac Training Therapy on Minute Ventilation/carbon dioxide Production Slope and Exercise Parameters in Patients with Severe Chronic Heart Failure in Short‑time Rehabilitation

Aim: Treatment for patients with severe chronic heart failure (CHF) (NYHA III, ejection fraction (EF) 30%) consists of medical or cardiac device theraphy, or heart transplantation. Cardiac exercise traning (CET) has also been shown to be effective and safe. Even though exercise therapy improves quality of life and exercise capacity, is not commonly used. The determination of the VE/VCO2 slope 34 during exercise have been shown to be useful for mortability risk stratification in CHF. This analysis investigated the effects of 3 weeks cardiac rehabilitation (CR) on exercise parameters and VE/VCO2 slope in CHF patients. Materials and Methods: Data from 35 patients with CHF (age 68 ± 11 years, 3 female, EF 29 ± 7%, maximum oxygen uptake (VO2max) 10.8 ± 2.7 mL/min/kg, NYHA class III, all ischemic heart disease) on optimal medication who underwent CR including aerobic endurance training theraphy combined with low dose local muscle strength for 3 weeks were evaluated retrospectively using 6 -min walking test, echocardiography and exercise testing. Results: All patients showed improvement in NYHA class, improvement in 6-min walking distance (285 ± 113 m to 431 ± 120 m, P 0.0001), increasing VO2max (10.8 to 12.9 ± 3.2 mL/kg, P 0.0001) and reduced VE/VCO2-slope (44.8 ± 9 to 37.1 ± 6, P 0.0001). These was no significant effect on EF (29 ± 8% to 32 ± 11%). Conclusion: CET for 3 weeks in severe CHF is associated with reduced VE/VCO2-slope and improved exercise capacity. Longer and randomized studies are needed to evaluate the role of VE/VCO2-slope in mortality risk stratification during training in CHF.