Assessment Of Pulmonary Vascular Adaptation To Exercise In Emphysematous Copd Patients With Mri - A Pilot Study

Introduction: In COPD emphysematous patients, parenchymal destruction is accompanied by a loss of pulmonary vessels. Its impact is assessed lately in clinical routine, when pulmonary hypertension with right-heart impairment develops. However, it has been shown that pulmonary vascular (PV) lesions occur early in the disease course and that pulmonary artery flow is impaired during exacerbations. We hypothesized that PV disease might participate to respiratory disability (Capron et al. ERR 2019; 28(152)). Objective: We aim to assess PV adaptation to exercise in emphysematous COPD patients as compared to non-smoker healthy controls. Methods: Magnetic resonance imaging is used to dynamically follow contrast agent passage through the pulmonary capillary bed, allowing for determination of pulmonary blood flow (PBF). This is measured at rest and after moderate exercise on a MRI-compatible cyclo-ergometer, yielding PBF variation (ΔPBF). Right cardiac output at rest and after exercise is accounted for in assessment of distal perfusion. Results expected: In this ongoing study (NCT 04126616), primary outcome is the comparison of ΔPBF between 10 emphysematous COPD patients and 10 age/gender-matched controls. Conclusion: We expect to highlight impaired pulmonary vascular adaptation to exercise which could be a future target for respiratory disability management and for preventive therapeutics.