P229 Feasibility of cardiopulmonary exercise testing in idiopathic pulmonary fibrosis

Introduction Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease of irreversible declining lung function. Reductions in forced vital capacity (FVC) and diffusion capacity for carbon monoxide (DL CO ) are the common clinical endpoints for prognostic monitoring and assessing treatment outcomes. The use of cardiopulmonary exercise testing (CPET) in IPF remains largely unexplored. Objectives To explore the feasibility of CPET as a clinical measure in IPF and identify associations with established clinical variables. Methods Seventeen patients with IPF were approached, and fifteen (88%) were recruited (13 male, 68.1±7.5 years). Incremental exercise testing to exhaustion was undertaken via electronically braked cycle ergometer. Variables included: peak oxygen consumption (VO 2peak ), peak work rate (WR peak ), nadir SpO 2 , ventilatory drive (V E /VCO 2 ), alongside standard clinical pulmonary function tests of FVC and DL CO . Pearson’s correlation coefficients established relationships between variables. Results One participant was excluded (high baseline systolic blood pressure). Eight out of fourteen (57%) participants reached volitional exhaustion. Five CPETs were terminated early due to desaturation (SpO 2 CO , 56.5%±11.4%; VO 2peak , 1.4±0.4 L.min -1 , 16.5±5.5 mL.kg -1 .min -1 ; WR peak , 104±42 W; SpO 2 , 90±3%; V E /VCO 2 , 27.1±6.4. Significant correlations were identified between: FVC and SpO 2 ( r =0.58, p=0.032), DL CO and V E /VCO 2 ( r =0.81, p peak ( r =0.58, p=0.03). Body-mass relative VO 2peak held moderate, but not significant relationships with FVC ( r =0.44, p=0.11) and DL CO ( r =0.53, p=0.51). Conclusions Initial findings from this study have found CPET to be acceptable to patients with IPF and potentially feasible as a testing measure. Preliminary results identified common exercise desaturation, suggesting less conservative SpO2 termination criteria (e.g. 80% cut-off) could be considered. Although exercise parameters held limited relationships with FVC and DL CO , results from VO 2peak identifies potential additional and dynamic prognostic information and warrants further investigation.