Utility of cardiopulmonary exercise testing in children and adolescents with non-cystic fibrosis bronchiectasis and primary ciliary dyskinesia.

<bold>Background:</bold> Cardiopulmonary exercise testing(CPET) is increasingly utilised as a predictor of lung health and prognostic indicator in a number of diseases, including cystic fibrosis(CF). Our aim was to assess the utility of CPET as a prognosticator in non-CF bronchiectasis patients(NCFB), including primary ciliary dyskinesia(PCD). <bold>Methods:</bold> Age and sex matched patients (n=20) from 3 cohorts(PCD/NCFB, CF and Control) had CPET and spirometry data retrospectively analysed. Forced expiratory volume in 1 second(FEV1) z-score, peak oxygen uptake(VO2peak (ml/min/kg)) peak oxygen uptake as a % of predicted(VO2peak %), VO2 at the first ventilatory threshold as a % of the predicted VO2peak(VT1) and breathing reserve at peak exercise(BR%) were analysed. ANOVA with Tukey pairwise comparisons were used to check statistical significance. <bold>Results:</bold> Mean age 12.6 ±2.6 years. 62% were female. CPET and spirometry results presented below. PCD/NCFB had a lower FEV1 than CF and Control and a lower BR% than CF(p<0.05). 43% of PCD/NCFB and 3% of CF had a BR%<15% indicating ventilatory limitation. <table-wrap><object-id>erj;64/suppl_68/OA4663/TB1</object-id><object-id>T1</object-id><object-id>TB1</object-id><table><colgroup><col></col><col></col><col></col><col></col></colgroup><tbody><tr><td></td><td>PCD/NCFB</td><td>CF</td><td>Control</td></tr><tr><td>FEV₁</td><td>-1.68 (−2.2,-1.2)</td><td>-0.20 (−0.7,0.3)</td><td>0.27 (−0.2,0.8)</td></tr><tr><td>VO_2peak</td><td>33.2 (29,37)</td><td>34.5 (31,38)</td><td>38.9 (35,43)</td></tr><tr><td>VO_2peak % pred</td><td>85 (77,94)</td><td>89 (81,97)</td><td>99 (91,108)</td></tr><tr><td>VT1</td><td>45 (39,50)</td><td>52 (46,57)</td><td>53 (48,59)</td></tr><tr><td>BR %</td><td>24 (16,31)</td><td>39 (32,47)</td><td>35 (27,42)</td></tr></tbody></table></table-wrap> <bold>Conclusion:</bold> Patients with PCF/NCFB have reduced lung function and have a greater incidence of ventilatory limitation during CPET compared with CF and control patients. CPET is a useful test, in conjunction with lung function, to assess PCD/NCFB patients annually and may have implications for long term prognosis in this cohort.