Cardiopulmonary Exercise Testing

Objective CPET-based VO2 peak as primary endpoint advances beyond the subjective patient-reported outcomes used in prior aerobic exercise trials in IBD. A clinically significant improvement is defined as a 5% increase in VO2 peak (1.41 mL/kg/min) from a baseline mean of 28.2 mL/kg/min. Superiority on VO₂peak is only concluded if superiority is first established for SF-36v2 physical function, implementing a gatekeeping procedure to control Type I error. CPET is the proposed non-invasive gold standard for preoperative fitness assessment, with consistent prognostic accuracy confirmed across large studies. In the METS substudy, nearly half of participants completed CPET before the 6MWT on the same day, which may have confounded 6MWT results. A CPET is considered suboptimal if peak respiratory exchange ratio does not exceed 1.1 or peak heart rate has not reached more than 85% of predicted. The same testing centre must be used for each participant at every time point to minimise inter-site variability. All CPETs in RESTORE are performed by cycle ergometry with rest, unloaded warm-up, ramp, and recovery phases. CPET is conducted and reported by certified cardiac rehabilitation specialist…