Pulmonary hypertension increases mortality risk in COPD
MedWire News: Pulmonary hypertension (PH) is common in patients with advanced chronic obstructive pulmonary disease (COPD) and is associated with functional impairments and increased mortality risk, research shows.
“Despite a growing body of literature on PH in COPD, the association between pulmonary artery pressure and functional endpoints such as the 6-minute walk distance (6MWD) has not been well explored,” explain Michael Cuttica (Northwestern University, Chicago, Illinois, USA) and team.
To address this, and investigate the effects of PH on survival in patients with advanced COPD, the researchers studied data on 4930 patients, aged an average of 56 years, with the respiratory condition who were listed for lung transplantation between 1997 and 2006.
All the patients underwent right heart catheterization (RHC), which confirmed the presence of PH in 30.4% and pulmonary venous hypertension (PVH) in a further 17.2% of participants.
The patients also underwent the 6MWD test and pulmonary function tests, and data on pre-transplant survival were analyzed.
The researchers found that patients with PH and PVH achieved significantly shorter distances on the 6MWD test than patients with normal hemodynamics, at 238 m and 228 m versus 261 m, respectively.
After accounting for factors such as height, weight, ethnicity, gender, and age at listing, mean pulmonary artery pressure was an independent predictor of 6MWD, as was forced vital capacity and patient age.
The researchers also found that the presence of PH and PVH were associated with increased risks for mortality on the waiting list, at hazard ratios of 1.27 and 1.40, respectively, after adjustment for potential confounding factors.
Cuttica and team conclude in the journal Respiratory Medicine: “We demonstrated that PH of any cause resulted in significant functional impairment as assessed by the 6MWD and was further associated with an increased risk of mortality.”
They add: “Our study underscores the need for right heart catheterization in establishing an accurate diagnosis to distinguish PH from PVH. Each of these diagnoses has potential implications for the management of these patients.”
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By Mark Cowen