Survival rates at one and five years for patients with group 1 pulmonary arterial hypertension at high altitude: A retrospective cohort study

Objectives: Group 1 pulmonary arterial hypertension (PAH) causes increased vascular resistance, right heart failure, and reduced survival. High-altitude PAH survival data are limited despite chronic hypoxia's potential impact on disease progression and risk stratification. The objective was to evaluate survival stratified by the European Society of Cardiology/European Respiratory Society (ESC/ERS) baseline risk score, REVEAL risk score 2.0, and etiologies in patients with PAH at high altitudes. Methods: A retrospective cohort study was conducted to evaluate functional and hemodynamic variables and risk stratification using the ESC/ERS baseline risk score and REVEAL risk score 2.0. One-year and five-year survival rates were determined from admission to the pulmonary hypertension program until death or the end of follow-up. Results: A total of 188 patients were included. The overall survival rate at one year was 95.8%, and at five years it was 86.8%. Precisely, 50% (95 out of 188) had congenital heart disease, 34% (63 out of 188) had idiopathic, and 13% (24 out of 188) had connective tissue disease. Risk stratification using REVEAL risk score 2.0 classified 58% (109 out of 188) of patients as low risk, 26% as intermediate risk, and 16% (30 out of 188) as high risk. Using the ESC/ERS baseline risk score, Stratification indicated 78% (146 out of 188) low risk, 21% (40 out of 188) intermediate risk, and 1% (2 out of 188) high risk. High risk according to ESC/ERS baseline risk score (p < 0.001) and REVEAL risk score 2.0 (p < 0.001) was associated with lower survival. Idiopathic etiology was associated with a lower survival rate (p = 0.011). Conclusion: The survival of patients with PAH at a high-altitude expert center was 95.8% at one year and 86.8% at five years. Risk stratification using the REVEAL risk score 2.0 and the ESC/ERS baseline risk score was associated with higher mortality in patients classified as high risk.