The effect of acute maximal exercise on the regional distribution of ventilation using ventilation MRI in CF

• Published in: Journal of cystic fibrosis 2021-07, Vol.20 (4), p.625-631
• Main Authors: Smith, Laurie J., Marshall, Helen, Bray, Jody, Wildman, Martin, West, Noreen, Horsley, Alex, Wild, Jim M.
• Format: Article
• Language: English
• Subjects: 129Xe MRI; Adolescent; Adult; Child; Cystic Fibrosis - diagnostic imaging; Cystic Fibrosis - physiopathology; Cystic Fibrosis - therapy; Exercise; Exercise Therapy; Female; Humans; Longitudinal Studies; Lung - physiopathology; Lung function; Magnetic Resonance Imaging; Male; Pulmonary Ventilation; Respiratory Function Tests; Ventilation; Young Adult
• ISSN: 1569-1993; 1873-5010
• DOI: 10.1016/j.jcf.2020.08.009

•In patients with CF, maximal exercise appears to often improve lung function.•Ventilation MRI detects significant changes in ventilation as a direct result of exercise.•Some have a worsening of ventilation post exercise, possibly due to proximal mucus plugging.•Ventilation MRI detects regional and global changes in lung ventilation.•The relationship of ventilation MRI and exercise capacity metrics needs further investigation. The importance of exercise in the management of people with CF is well recognised, yet the effect of exercise on lung function is not well understood. FEV1 is insensitive to the detection of small changes in lung function. Ventilation MRI and LCI are both more sensitive to mild lung disease than FEV1 and may be better suited to assess the effects of exercise. Here we assessed the short-term effects of maximal exercise on the distribution of ventilation using ventilation MRI and LCI. Patients with CF and a range of lung disease were assessed. Baseline LCI and ventilation MRI was followed by a maximal cardio-pulmonary exercise test (CPET). Repeated ventilation MRI was performed within 30 minutes of exercise termination, followed by LCI and finally by FEV1. 13 patients were recruited and completed all assessments. Mean (SD) age was 25 (10) years and mean (SD) FEV1 z-score was -1.8 (1.7). Mean LCI at baseline was 8.2, mean ventilation defect percentage on MRI (VDP) was 7.3%. All patients performed maximal CPET. Post-exercise, there was a visible change in lung ventilation in 85% of patients, including two patients with increased ventilation heterogeneity post-CPET who had normal FEV1. VDP and LCI were significantly reduced post-exercise (p < 0.05) and 45% of patients had a significant change in VDP. Acute maximal exercise directly affects the distribution of ventilation on ventilation MRI in patients with CF. This suggests that exercise is beneficial in CF and that ventilation MRI is suitable to assess airway clearance efficacy.