Outcome of pulmonary hypertension associated with respiratory disease

Introduction: Pulmonary hypertension (PH) is a common complication in chronic lung diseases, but its characteristics are mostly unknown. The Spanish Registry for PH associated with respiratory diseases (REHAR) was created to define these characteristics. Methods: Patients were enrolled in the REHAR registry by 13 PH centres (September 2017-January 2019). Functional parameters, respiratory gases, lung hemodynamics, PH treatment and survival data were analysed according to the underlying diagnosis (COPD: chronic obstructive pulmonary disease; ILD: interstitial lung disease; CPFE: combined pulmonary fibrosis/emphysema). Baseline risk was assessed with 2 scores (Hoeper M et al, ERJ 2017; Boucly A et al, ERJ 2017). Results: patients (n=115) did not show differences in hemodynamic, functional status or gas exchange, except for the expected differences in pulmonary function profiles and lower mixed venous blood saturation (SvO2) in the COPD compared to the ILD group (63% vs 71%, p = 0.03). A minority of patients, mostly with severe PH (defined as in 6th World Symposium on PH) received PH therapy. The COPD group showed better survival (3-year: COPD 63%, ILD 22%, CPFE 27%, p<0.001), but no differences were found among groups when only severe PH was considered nor between treated and untreated patients. Neither of the two risk-stratification methods correlated significantly with mortality. Conclusions: results from the REHAR registry show that half of the patients suffered from severe PH, likely due to referral bias; that PH treatment is restricted to patients with severe PH and not associated with better outcome; that the risk-stratification tools used do not reflect outcomes in this cohort of patients. Funded CIBERES, SEPAR