Clinical phenotypes and outcomes of severe pulmonary hypertension associated with chronic obstructive pulmonary disease

Introduction: Severe pulmonary hypertension (PH) is rare in COPD. The characteristics of this population, as their evolution under PAH treatments, remain largely unknown. We aimed to characterize phenotypes of patients with severe PH associated with COPD and to evaluate the efficacy and safety of specific PAH treatments in this population. Methods: We conducted a multicenter retrospective observational study including patients with severe PH associated with COPD. Patients underwent right heart catheterization and complete PFT at baseline, and between 3 and 12 months after diagnosis. Results: Heighty-nine patients with severe PH were included (mean mPAP=46mmHg, mean CI=2.53+/−0.6L/min/m2, mean PVR of 8.5+/−3.2WU). Seventy-one percent of patients had mild to moderate airway obstruction (mean FEV1=64%). A greater hemodynamic and vascular impairment was found in patients with FEV1 ≥ 80%. The median survival was 25.5 months, and unrelated to FEV1. Among the 65 patients who received PAH drugs and had at least 3 months of follow-up, significant improvements were found in hemodynamics (mean ΔCI=+0.58(+0.05;+1.10)), dyspnea, 6MWD (+61m (+16.73;+141.94)) and survival in these patients compared to untreated patients. Conclusion: Patients with severe PH associated with COPD have a poor prognosis, unrelated to the degree of airway obstruction. The severity of hemodynamic impairment in patients with low obstruction raises the question of a specific phenotype and the existence of other factors than airway obstruction responsible for the development of pulmonary hypertension. The real effect of specific PAH treatments calls for a randomized study.