The clinical and hemodynamic characteristics of pulmonary hypertension in patients with OSA-COPD overlap syndrome

Background Our study aimed to assess the clinical and hemodynamic characteristics of pulmonary hypertension (PH) in patients with overlapping obstructive sleep apnea (OSA) and chronic obstructive pulmonary disease (COPD), referred to OSA-COPD overlap syndrome (OS). Methods We enrolled a total of 116 patients with OS, COPD, or OSA who underwent right heart catheterization (RHC) due to suspected pulmonary hypertension (PH). We conducted a retrospective analysis of the clinical and hemodynamic characteristics of these patients. Results Among the three groups (OS group, n=26; COPD group, n=36; OSA group,n=54), the prevalence of PH was higher in the OS group (n=17, 65.4%)compared to OSA group (n=26,48.1%) and COPD group (n=20,55.6%). Among three groups with PH, the superior vena cava pressure (CVP) and right ventricular pressure (RAP) were higher in the OS group than in the OSA group (P<0.05). Patients in the OS and COPD groups had higher pulmonary artery wedge pressure (PAWP) than in the OSA group (14.88±4.79 mmHg, 13.45±3.68 mmHg vs. 11.00±3.51 mmHg, respectively, P<0.05). OS patients with PH exhibited higher respiratory event index (REI), time spent with SpO2 <90%, oxygen desaturation index (ODI), minimal SpO2 (MinSpO2) and mean SpO2 (MSpO2) compared to OS patients without PH. After adjusting for potential covariates, we found that MinSpO2 (OR 0.937, 95% CI 0.882-0.994, P=0.032), MSpO2 (OR 0.805, 95% CI 0.682-0.949, P=0.010), time spent with SpO2 <90% (OR 1.422, 95% CI 1.137-1.780, P=0.002), and FEV1% pred (OR 0.977, 95% CI 0.962-0.993, P =0.005) were related to the development of PH. Conclusions Patients with OS showed higher prevalence of PH, along with higher PAWP, CVP and RAP. Worse nocturnal hypoxemia was found in OS patients with PH.