Poster Session I: Cardiac rehabilitation and chronic heart failure

Abstract

P85 The effect of high-intensity training on ventilatory efficiency in chronic heart failure MGJ Gademan, J Myers, K Brunner, W Kottman, C Boesch, P Dubach Palo Alto Veterans Affairs Medical Center / Stanford University, Palo Alto, United States of America, Kantosspital, Chur, Switzerland Topic: Cardiovascular rehabilitation Background: The oxygen uptake efficiency slope (OUES) is a relatively new measure of ventilatory efficiency which has prognostic value in chronic heart failure (CHF) patients. The OUES has the advantage that it is independent of exercise capacity achieved. Little is known regarding the effects of exercise training on OUES in CHF. Hypothesis: High-intensity training improves the OUES in patients with CHF. Methods: Fifty CHF patients were randomized to a 2-month high-intensity residential exercise training program (EXTR, N1⁄424) or to a control group (CTRL, N1⁄426). Before and after the study period, maximal cardiopulmonary exercise testing was performed. Peak oxygen uptake (VO2peak), VE/VCO2 slope, OUES, and minute-by-minute lactate responses were measured. Results: Exercise training significantly increased VO2peak (23%), peak minute ventilation (23%), exercise time (29%) andpeakworkload (28%),whereasno improvementswereobserved in controls (p<0.05). These responses also improved at the lactate threshold (VO2peak 44%, minute ventilation 44%, exercise time 71% and workload 69%). The OUES increased by 11% in the EXTR group and 4% in the CTRL group (p1⁄40.46 between groups). However, the within group change in the EXTR group was highly significant (p1⁄40.003). At baseline, EXTR patients had an OUES that was 69% of the predicted value, and this improved to 78% after finishing the program (p within group1⁄40.004). Conversely, no differences were observed in the VE/VCO2 slope. Conclusions: In these relatively healthy CHF patients, high intensity training resulted in marked improvements inVO2peak, exercise time andworkload.Trainingalso improved theOUESbut not the VE/VCO2 slope. Among measures of ventilatory inefficiency, the OUES may respond more favorably to exercise training than the VE/VCO2 slope. Therefore, an improvement in the OUES may be a more achievable outcome from exercise training in relatively healthy CHF patients.