Physiological predictors of resting pulmonary hypertension associated with COPD: a retrospective analysis

Abstract

BackgroundResting pulmonary hypertension (PH) is not uncommon in patients with chronic obstructive pulmonary disease (COPD). In the current study, we aimed to identify physiological predictors of resting PH in patients with COPD.MethodsWe retrospectively analyzed data derived from right heart catheterization in sixty-nine stable patients with COPD. Patients were categorized into COPD-PH (n = 33) and COPD-non-PH (n = 36), based on the “6th World Symposium on PH.”ResultsDemographics, forced expiratory volume in 1 s (FEV1), lung volumes, cardiac output, and cardiac index were similar between groups, yet COPD-PH had greater pulmonary vascular resistance (PVR) and lower resting PaO2 (P < 0.05). The proportion of COPD-PH patients did not differ across the range of FEV1 (χ2 = 3.01, P = 0.22). No correlations were found between PVR and the degree of airflow obstruction or resting hyperinflation. Resting PaO2 was the only predictor of both pulmonary artery pressure and PVR.ConclusionsIncreased PVR, in response to arterial hypoxemia or directly induced by tobacco smoking, is likely the key factor that led to resting PH in the current sample of patients with moderate-severe COPD, regardless of the degree of airflow limitation or resting hyperinflation.