Clinical characteristics of patients with a risk of pulmonary artery hypertension secondary to ARDS in a high-altitude area.

Background: Hypoxaemia plays an important role in the development of pulmonary artery hypertension (PAH). Patients with acute respiratory distress syndrome (ARDS) in a high-altitude area have different pathophysiological characteristics from those patients in the plains. The goal of our study was to explore the clinical characteristics of PAH secondary to ARDS in a high-altitude area.

Methods: This was a prospective study conducted in the affiliated Hospital of Qinghai University. Two investigators independently assessed pulmonary artery pressure (PAP) and right ventricular function by transthoracic echocardiography. Basic information and clinical data of the patients who were enrolled were collected. A multivariable logistic regression model was used to evaluate the risk factors for PAH secondary to ARDS in the high-altitude area.

Results: The incidence of PAH secondary to ARDS within 48 hours in the high-altitude area was 44.19%. Partial pressure of oxygen/fraction of inspired oxygen <165.13 mm Hg was an independent risk factor for PAH secondary to ARDS in the high-altitude area. Compared with the normal PAP group, the right ventricular basal dimensions were significantly larger and the right ventricular tricuspid annular plane systolic excursion was lower in the PAH group (right ventricular basal dimensions: 45.47±2.60 vs 40.67±6.12 mm, p=0.019; tricuspid annular plane systolic excursion (TAPSE): 1.82±0.40 vs 2.09±0.32 cm, p=0.021). The ratio of TAPSE to systolic PAP was lower in the PAH group (0.03±0.01 vs 0.08±0.03 cm/mm Hg, p<0.001).

Conclusions: The incidence of PAH in patients with ARDS in our study is high. PAH secondary to ARDS in a high-altitude area could cause right ventricular dysfunction.

Trial Registration Number: NCT05166759.