Pulmonary Hypertension Common in Patients With COPD Referred for Catheterization, Study Finds

Pulmonary hypertension (PH), which is associated with high mortality, was found to be more common in patients with chronic obstructive pulmonary disease (COPD) who were referred for a right heart catheterization (RHC), according to a study published in Pulmonary Circulation.

The study was conducted using data extracted from the University of Vanderbilt’s Synthetic Derivative database, which is a deidentified version of Vanderbilt’s electronic medical record. All patients who underwent RHC between 1998 and 2017 were identified. All patients needed to be 45 years and older to be included in this study to increase specificity for COPD; indeterminate status of COPD disqualified a patient from participating.

A total of 1509 patients with COPD were included in this study. PH was prevalent in 80% of patients with COPD, but this decreased to 66% when applying the historical mean pulmonary artery pressure (mPAP) cutoff of at least 25 mm Hg.

Patients with COPD-PH were younger and had a higher body mass index (BMI), compared with patients with COPD without PH; were more likely to be Black; and had a higher prevalence of diabetes, atrial fibrillation, and heart failure than patients with COPD without PH.

The risk of death was increased in patients with COPD-PH compared with patients with COPD (HR, 1.70; 95% CI, 1.28-2.26) when adjusting for age, sex, and race. Patients with COPD-combined postcapillary and precapillary-PH had the highest risk of death (HR, 2.39; 95% CI, 1.64-3.47) vs patients with COPD alone. COPD-precapillary-PH (HR, 1.92; 95% CI, 1.22-3.02) and COPD-isolated postcapillary-PH (HR, 1.60; 95% CI, 1.16-2.22) had similar increased mortality risk.

Elevations in risk of death were also found in patients with COPD-PH defined as mPAP of 21 to 24 mm Hg with pulmonary vascular resistance greater than or equal to 3 WU or mPAP of 25 to 34 mm Hg and COPD with severe PH as mPAP of at least 35 mm Hg or mPAP greater than or equal to 25 mmHG with low cardiac index. COPD-PH had a 61% increased mortality risk (HR, 1.61; 95% CI, 1.20-2.21) whereas COPD-PH severe had a 106% greater risk (HR, 2.06; 95% CI, 1.50-2.82).

Patients with COPD-PH referred to RHC had higher right atrial pressure, reduced right ventricular function, increased left atrial diameter, and decreased stroke volume and PA oxygen saturation compared with patients with COPD alone.

There were some limitations to this study. It was conducted at a single center, the selection of patients with only RHC data may have led to subgroup bias, exercise testing was not performed during RHC but could have increased the number of patients with PH in the study, and treatment options and guidelines for COPD changed in the 17 years that the study took place and could not be accounted for. Using Global Initiative for Chronic Obstructive Lung Disease criteria to determine COPD in patients also likely increased specificity for COPD but sacrificed sensitivity, as it is likely some patients who were deemed indeterminate had COPD.

The researchers concluded that PH is common in patients with COPD who are referred for RHC. They also concluded that PH is often associated with multimorbidity and high mortality, which have implications for risk factor management.

“These results support an integrated approach to objectively identify both diseases at an early stage and to optimize control of respiratory and cardiovascular conditions. Additional studies providing new data on the pathogenesis and management of patients with COPD and PH are needed,” the authors wrote.

Reference

Cook DP, Xu M, Martucci VL, et al. Clinical insights into pulmonary hypertension in chronic obstructive pulmonary disease. Pulm Circ. 2022;12:e12006. doi:10.1002/pul2.12006