Clinical characteristics of pulmonary hypertension patients living in plain and high-altitude regions.

Objective: The demographic characteristics, ratio of aetiologies and biochemical parameters of adult patients with pulmonary hypertension (PH) living in plain and high-altitude regions were investigated and analysed.

Methods: In total, 2846 adult patients with PH hospitalized from 2010 to 2015 in the Second Xiangya Hospital of Central South University and Qinghai Red Cross Hospital were retrospectively investigated.

Results: (1) In the present study, the numbers of patients with PH in both the plain and high-altitude regions increased annually (P < 0.05), and the in-hospital prevalence of PH significantly increased over time in the high-altitude region. PH was more common in women in the plain region. Furthermore, compared with PH patients living in the plain region, those living in the high-altitude region were older (P < 0.05) and had higher smoking rates (P < 0.05). In the plain region, the greatest proportion of patients with PH belonged to group 2 (PH because of left heart disease), while in the high-altitude region, group 3 (PH because of lung diseases and/or hypoxia) was the most common (P < 0.05). (2) Haemoglobin levels, red blood cell counts, mean platelet volumes and platelet volume distribution widths were lower in PH patients living in the plain region than in those living in the high-altitude region. Furthermore, platelet counts were higher in patients living in the plain region than in those living in the high-altitude region (P < 0.05). The BNP/NT-proBNP levels were higher in PH patients living in the plain region (45.5%), which were mostly in group 4, than in those living the high-altitude region (P < 0.05).

Conclusions: The data from the hospitals in both the plain and high-altitude regions show a tendency towards increased in-hospital prevalence of PH over the last 6 years. The most common aetiologies of PH in patients living in the plain region and high-altitude regions were left heart disease and lung disease, respectively. Compared with PH patients living in the plain region, those living in the high-altitude region had better cardiac function and less severe PH.