Phenotyping exercise limitation of patients with Interstitial Fibrosing Lung Disease: the importance of exercise hemodynamics

Introduction and objective: Left-heart dysfunction and pulmonary vasculopathy are increasingly recognized as contributing factors of exercise capacity limitation in interstitial fibrosing lung disease (IFLD). Moreover, the clinical significance of exercise pulmonary hypertension (ePH) in pulmonary and cardiac diseases has been documented, representing a risk factor for decreased exercise capacity and survival, progression to resting pulmonary hypertension (PH) and overall clinical worsening. We conducted a prospective study aiming at: (a) assessing the prevalence of PH and ePH in a cohort of 40 functionally limited patients with IFLD, (b) determining the post-capillary (postC) or pre-capillary (preC) etiology of either PH or ePH in this cohort, and (c) examining the correlations between invasively and non-invasively measured exercise variables among hemodynamic groups.