TY - JOUR T1 - Pulmonary vascular response patterns during exercise in interstitial lung disease (ILD) JF - European Respiratory Journal JO - Eur Respir J VL - 44 IS - Suppl 58 SP - 1397 AU - Luiza Helena Degani- Costa AU - Barbara Levarge AU - Subba R. Digumarthy AU - R. Scott Harris AU - Gregory D. Lewis Y1 - 2014/09/01 UR - http://erj.ersjournals.com/content/44/Suppl_58/1397.abstract N2 - 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±0.2 in ILD-PH, but there was no difference between slopes in ILD-nonPH and controls (1.9±0.2 vs. 1.5±0.1 respectively, p>0.05). ILD-PH had lower peak QT than ILD-nonPH (9.3±0.6 vs. 12.5±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±0.9 ml/kg/min vs. 17±1.1, p=0.012) and controls (19.8±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. ER -