1The North-Western Federal Medical Research Center named after V.A.Almazov, the research laboratory of chronic heart failure - Saint-Petersburg, - Russian Federation
Introduction: In the world practice, the selection of physical training intensity of patients with CHF is on the basis of anaerobic threshold achievement during cardiorespiratory test (CPET). But the majority of patients with severe CHF are not able to achieve it during the CPET, that requires the use of certain indicators in the appointment of physical training. This alternative indicator can be lactate threshold, which achieved first during the execution of the CPET.
Purpose: To evaluate the effectiveness of aerobic physical exercise in HF patients, selected on the basis of achievement the lactate threshold during CPET and based on functional class of heart failure and comorbidity.
Methods: 77 patients, CHF NYHA II -III (under the supervision of cardiologists-experts in heart failure) were randomized into two groups - primary (aerobic training) and control (standard treatment of heart failure). Main group - 64 patients, mean age 54±12,5 years, body mass index (BMI) 26,46±6,4 kg/m2, among them 46 patients (72%) had III CHF functional class and 18 patients (28%) – II CHF functional class. The control group - 13 patients, age 53±17 years, BMI was 25,4±6.8 kg/m2, 12 patients had III CHF functional class, 1 patient – I. CPET, quality of life (QOL), exercise tolerance (ET) was assessed at baseline and after 1,3,6 months of follow-up. The CPET served on tredmile using hardware " Охусоn Рrо ", Jaeger, Germany. Echocardiography (EchoCG) were performed at baseline and after 6 months. The data were statistically processed using software package "Statistika, 6.0".
Results: In the main group after 6 months of training EF increased by 7.5±0.5% and End-diastolic volume decreased by 6±2.0 ml from baseline, QOL was changed by 17.5±8 points (significant regression of symptoms), ET increased by 9±1 points. After 1 month of observation VO2 peak increased by 2.6±0.1 ml/min/kg after 6 months – 4.4 ml/min/kg. In the control group showed an increase EF 4±1,1%, End-diastolic volume decreased by 68±14,8 ml, the change of QOL 14± 7,22 points, the increase in ET at 1.5 points. Decreased VO2 peak in a month 1,05±1,2 ml/min/kg, after 6 months – 1,7 ml/min/kg. Revealed a strong positive correlation between the initial values of VO2 peak and EF (rEF=0,4, p), and between baseline levels of sodium, hemoglobin and the effectiveness of physical rehabilitation (rNa= 0,41, p,0,05; rHb = 0,45, p<0,05).. There was a positive impact of the initial content of red blood cells (rEr=0,6, p=0.03), sodium (rNa=0,4, p=0.05), LV EF (r=0.5, p=0.05) and level VE at the peak of exercise load (r=0.5,p=0.01) on training effectiveness. The level of BNP and a long history of CHF had a negative effect on the result of physical training (rBNP=-0,7, p=0.05; rCHF=-0,6, p=0.05).
Conclusion: Aerobic physical exercise in CHF patients, selected on the basis of lactate threshold achievement during the CPET, is effective in improving values of CPET, EchoCG, QOL and increasing exercise tolerance.