Feasibility Of A Cardiopulmonary Exercise Test ( Cpet) Derived High-Intensity Interval Training Programme (Hiit) In Idiopathic Pulmonary Fibrosis (Ipf)

Introduction: Exercise training is recommended for IPF patients but the optimum program and the mechanisms underlying improvements in exercise capacity are unknown. We tested feasibility of a HIIT in IPF. Methods: A single-centre study of IPF patients. An 8-week twice-weekly cycle-ergometer based HIIT was personalised using participants volume of oxygen consumption at anaerobic threshold (VO2AT) and peak (VO2peak) assessed by incremental CPET. Primary outcome was endurance time on constant load test at 75% VO2peak. Ethical approval obtained (REC 17/SC/0342). Results: Interim analysis of 11 patients. Baseline demographics as follows; males 82% with mean (SD) age 73.5years (6.8), FVC% 76.5 (13.4) and DLCO% 50.1 (15.8). Participants had significantly impaired exercise capacity at baseline with mean (SD) VO2peak of 12.3ml/kg/min (3.3) and VO2AT 8.3ml/kg/min (1.3). Participants had good adherence to HITT with mean of 15/16 sessions attended with no serious adverse events. HITT led to clinically meaningful improvement in mean endurance time [pre 8.3min vs post 16.8min difference 8.5min (95%CI 4.2-12.8) p<0.01] and 6min walk [pre 374m vs post 409m difference 35m (95%CI 0.6-69.4) p<0.05]. Significant increase was also observed in mean peak minute ventilation (peakVE) [pre 60.2L/min vs post 69.3L/min p=0.02]. However no change was observed in either VO2peak or VO2AT following HITT. Conclusion: A CPET derived HIIT was feasible in this cohort of IPF patients and led to significant improvement in endurance time and 6min walk. Increased peakVE following HITT suggests improved ventilatory mechanics may in part account for increased exercise test performance.