Risk factors and outcomes of HPH in high-altitude residents via echocardiographic evaluation

Abstract Background: Over 80 million people reside above 2,500 meters, where hypobaric hypoxia elevates the risk of hypoxic pulmonary hypertension (HPH). In Qinghai, China (>3,000 m), over 5 million face a high HPH burden amid scarce medical resources. Objective: To assess risk factors and clinical correlates of HPH severity and mortality in high-altitude residents using echocardiography. Methods: This retrospective study included 627 patients diagnosed with HPH (PASP ≥50 mmHg) via echocardiography at a tertiary hospital in Qinghai Province, China, from January 2018 to December 2022. Patients were categorized into moderate (50 ≤ PASP < 70 mmHg) and severe (PASP ≥70 mmHg) HPH groups. Clinical, biochemical, and echocardiographic data were collected, with mortality assessed via telephone follow-up after at least one year. Logistic regression identified factors associated with severe HPH, and Cox regression determined mortality predictors. Results: Of the 627 patients, 360 (57.4%) had moderate HPH and 267 (42.6%) had severe HPH. The severe HPH group exhibited lower albumin (33.50 ± 5.54 g/L vs. 35.45 ± 6.65 g/L, p < 0.001) and higher APTT (34.04 ± 7.48 s vs. 31.44 ± 6.91 s, p < 0.001), LPa (142.27 ± 126.64 mg/L vs. 110.67 ± 101.01 mg/L, p = 0.001), and rates of heart failure, cyanosis, and right ventricular hypertrophy (all p < 0.05). Logistic regression identified APTT (OR = 1.050, 95% CI: 1.014–1.087, p = 0.007), LPa (OR = 1.002, 95% CI: 1.001–1.004, p = 0.003), cyanosis (OR = 1.814, 95% CI: 1.235–2.663, p = 0.002), and right ventricular hypertrophy (OR = 3.501, 95% CI: 1.631–7.514, p = 0.001) as factors associated with severe HPH. Multivariate Cox regression identified LPa (HR = 3.461, 95% CI: 2.021–5.928, p < 0.001), atrial fibrillation (HR = 2.534, 95% CI: 1.365–4.705, p = 0.003), heart failure (HR = 2.316, 95% CI: 1.134–4.730, p = 0.021), and alcohol consumption (HR = 3.230, 95% CI: 1.277–8.171, p = 0.013) as mortality predictors. Conclusion: In high-altitude Qinghai residents, APTT, LPa, cyanosis, and right ventricular hypertrophy drive severe HPH, while LPa, atrial fibrillation, heart failure, and alcohol use predict mortality. Monitoring APTT and LPa may aid early detection, and managing modifiable factors like alcohol and atrial fibrillation could lower mortality in resource-limited settings.