@article {Degani- Costa1397, author = {Luiza Helena Degani- Costa and Barbara Levarge and Subba R. Digumarthy and R. Scott Harris and Gregory D. Lewis}, title = {Pulmonary vascular response patterns during exercise in interstitial lung disease (ILD)}, volume = {44}, number = {Suppl 58}, elocation-id = {1397}, year = {2014}, publisher = {European Respiratory Society}, abstract = {When overt pulmonary hypertension (PH) arises in ILD it contributes to exercise intolerance. Objectives: We sought to determine the functional significance of abnormal pulmonary arterial pressure (PAP) responses to exercise in ILD. Methods: 27 ILD patients without cardiac disease and 11 matched healthy controls underwent invasive cardiopulmonary exercise testing (iCPET). mPAP was indexed to cardiac output (QT) during exercise, with mPAP-QT slope>=3 mmHg-min/L defined as an abnormal pulmonary vascular (PV) response. Results: All control subjects had mPAP-QT slope\<3, whereas 13 ILD patients had mPAP-QT slope>=3 and 2 other subjects had resting PH with inability to complete iCPET; these 15 patients were labeled ILD-PH. Subjects without PH and with mPAP-QT slope\<3 were labeled ILD-nonPH (n=12). ILD-PH and ILD-nonPH did not differ in terms of age, gender, BMI, pulmonary function testing or degree of exercise desaturation. mPAP-QT slope was 3.9{\textpm}0.2 in ILD-PH, but there was no difference between slopes in ILD-nonPH and controls (1.9{\textpm}0.2 vs. 1.5{\textpm}0.1 respectively, p\>0.05). ILD-PH had lower peak QT than ILD-nonPH (9.3{\textpm}0.6 vs. 12.5{\textpm}0.8; p=0.006), but peak QT was similar between ILD-nonPH and controls (p\>0.05). Peak VO2 was lower in ILD-PH than in ILD-nonPH (13.0{\textpm}0.9 ml/kg/min vs. 17{\textpm}1.1, p=0.012) and controls (19.8{\textpm}1.7, p=0.003). ILD-PH had increased dead space ventilation (VD), with greater VD/VT and VE/VCO2. Conclusion: In ILD, a mPAP-Q\>3 is associated with lower peak VO2 and QT, as well as increased VD. While non-invasive parameters were unable to predict those with abnormal PV response to exercise, iCPET-derived mPAP-QT slope may aid in identifying physiologically significant early PV disease in ILD.}, issn = {0903-1936}, URL = {https://erj.ersjournals.com/content/44/Suppl_58/1397}, eprint = {https://erj.ersjournals.com/content}, journal = {European Respiratory Journal} }