New approach for submaximal cardiopulmonary exercise testing in COPD aiming to reduce variability in endurance time

Abstract

Use of cardiopulmonary exercise testing (CPET) at a submaximal level (Endurance test) is limited, in monitoring disease status and treatment effect in COPD, both in clinical practise and clinical trials, due to large interindividual variability. The present study targeted the heterogeneity in the duration of Endurance test intending to modify both the intensity and the method of applying workload, in order to accomplish shorter (between 180s-480s) and less variable endurance time,according to recommendations of ERS. 21 COPD patients were included in a cycle CPET double-blind,randomised cross-over study (LABA/LAMA vs placebo) comparing: 1) Standard Endurance Test (SET),with a 1-minute loadless pedalling warm-up period followed by a constant load at 75% of Wmax (maximum workload), 2) New Endurance Test (NET), with a 4-min warm-up (1-min loadless pedalling followed by 3-min at 30% of Wmax), followed by an instant increase at 70% of Wmax and thereafter a linear increase of 1% of Wmax per min up to 90% of Wmax. We argue that a submaximal incremental test with a warm-up period at 30% of Wmax, followed by a linear increase of workload can significantly reduce endurance time variation compared to a submaximal constant workload exercise test .Whether such an incremental test could detect differences after intervention remains to be seen.