Patients with pulmonary hypertension (PH) as a complication of chronic obstructive pulmonary disease (COPD) have worse functional impairment and higher mortality, compared with patients who have idiopathic pulmonary arterial hypertension (IPAH).
Despite these factors, some patients with more severe PH in COPD may respond to treatment and show clinical improvement after treatment, according to recent research published in the journal CHEST®.
Carmine Dario Vizza, MD, of the pulmonary hypertension unit, department of cardiovascular and respiratory diseases at Sapienza University of Rome, and colleagues evaluated patients in the Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension (COMPERA) database, enrolled up to August 2020, identifying 68 patients with moderate PH and COPD and 307 patients with severe PH and COPD. The researchers compared the PH and COPD groups with 307 patients who had idiopathic pulmonary arterial hypertension.
Overall, mostly older men made up the group of patients with moderate (50%; mean, 68.5 years) and severe PH in COPD (61%; mean 68.4 years), compared with those who had IPAH (37%; mean 61.7 years. Oral monotherapy for patients with PH and COPD was the main treatment, consisting of phosphodiesterase-5 inhibitors, while most patients with IPAH received endothelin receptor antagonists.
On functional tests, patients in the PH and COPD group tended to perform poorer on the 6-minute walking distance (6MWD) and World Health Organization functional class (WHO FC) than patients with IPAH. Specifically, among 42.7% of patients in both group for whom follow-up data were available, there was a similar frequency of improvement for 6MWD of 30 meters or more from baseline for both PH and COPD and IPAH groups (46.9% vs. 52.6%; P = .294), but there were significant differences between 6MWD between patients with moderate and severe PH and COPD (51.6% vs. 31.6%; P = .04). There was a nonsignificant improvement in WHO FC improvement of one or more classes for 65.6% of patients with PH and COPD and 58.3% of patients with IPAH with follow-up data available, with 28.5% of patients with PH in COPD improving compared with 35.8% of patients with IPAH (P = .078) and nonsignificant differences between moderate and severe PH and COPD (19.0% vs. 30.4%; P = .188).
Comparing outcomes
Follow-up data were available for 84% of patients with IPAH and 94% of patients with PH and COPD. Dr. Dario Vizza and colleagues found 45.7% of patients in the PH and COPD group and 24.9% of patients in the IPAH group died during follow-up, while 1.1% in the PH and COPD group and 1.5% of patients in the IPAH group underwent lung transplantations. For patients with moderate PH and COPD, 31.3% died and none underwent lung transplantation, while 49.0% of patients in the severe PH and COPD group died and 1.4% underwent lung transplantations.
Patients in the moderate PH and COPD group were more likely to discontinue treatment (10.9%), compared with patients with IPAH (6.6%) and patients with severe PH and COPD (5.2%). The most common reasons for discontinuations were tolerability and efficacy failure; the IPAH group had 63% of patients discontinue because of tolerability and 7% for efficacy failure, 47% of patients in the severe PH and COPD group discontinued because of tolerability and efficacy, and 29% discontinued treatment for tolerability and 57% for efficacy failure in the moderate and COPD group.
The researchers said male sex, low 6MWD, and high pulmonary vascular resistance at baseline were predictive of poorer outcomes for PH and COPD, but patients with more severe PH and COPD had better outcomes if they improved by 30 meters or more in 6MWD, or improved in WHO FC after receiving medical therapy. For patients with IPAH response to therapy was better among patients who were younger, had higher WHO FC, had high diffusing capacity of the lung for carbon monoxide, had high mean pulmonary artery pressure, and had low PCO2.
“Our data suggest that PH-targeted drug therapy in patients with COPD and severe PH may improve exercise tolerance and WHO FC in a subgroup of patients and that patients with COPD and PH who respond to therapy may have a better prognosis than patients who do not show clinical improvement. These findings need to be explored further in prospective, randomized controlled clinical studies,” the authors concluded.