Objectives Pulmonary hypertension associated with chronic obstructive pulmonary disease (PH-COPD) is associated with poor outcomes, yet resting haemodynamics incompletely capture disease severity. We evaluated whether integrating submaximal cardiopulmonary exercise testing variables with transthoracic echocardiographic and pulmonary function test parameters improves prognostic assessment in PH-COPD beyond resting haemodynamics alone. Setting Single-tertiary pulmonary vascular disease referral centre in the USA. Participants 67 patients with PH-COPD who underwent right heart catheterisation and complementary non-invasive testing between 2019 and 2024. Primary outcome measures The primary outcome was a composite of heart failure hospitalisation or all-cause mortality. Methods Associations between physiologic variables and outcomes were assessed using Cox proportional hazards models and survival tree analysis. Results The composite outcome occurred in 47.1% of patients over a median follow-up of 518 (229–897) days. Several non-invasive dynamic physiologic variables were associated with adverse outcomes, including lower gas exchange-derived pulmonary vascular capacitance (Gx CAP ) (HR 0.997, 95% CI 0.995 to 0.999; p=0.013), lower oxygen uptake efficiency slope (HR 0.983, 95% CI 0.968 to 0.998; p=0.030), lower submaximal VO 2 (HR 0.978, 95% CI 0.959 to 0.997; p=0.022) and lower ETCO 2 (HR 0.886, 95% CI 0.820 to 0.957; p=0.002). Higher estimated right ventricular systolic pressure (eRVSP) on echocardiogram (HR 1.015, 95% CI 1.001 to 1.029; p=0.032) and pulmonary vascular resistance (PVR) on right heart catheterisation (HR 1.087, 95% CI 1.005 to 1.176; p=0.038) were also associated with adverse outcomes, although no optimal prognostic PVR threshold was identified. In the survival tree model, Gx CAP 45 mm Hg represented the highest-risk subgroup (relative HR 4.4). Including PVR did not improve prognostic performance of the analysis. Conclusions Dynamic exercise-derived physiologic markers provide prognostic information complementary to resting haemodynamic assessment in PH-COPD and may improve risk stratification across this heterogeneous population.
Tarras et al. (Mon,) studied this question.