Survival and Hemodynamic Effects of Parenteral Prostanoids in High‐Altitude Group 1 Pulmonary Hypertension: A Retrospective Cohort Study

Background In Latin America, the evidence regarding the use of prostanoids at high altitude in patients with Group 1 pulmonary hypertension (PH‐1) is limited. Therefore, it is essential to describe the clinical characteristics and outcomes associated with prostanoid treatment in this population. Methods This retrospective study involved patients with PH‐1. Hemodynamic and clinical variables were compared before the initiation of prostanoids and during clinical follow‐up. Overall survival was analyzed using Kaplan–Meier estimation, with survival rates calculated at 3 and 5 years. The strength of the association for each variable concerning the proposed outcomes was estimated by calculating the odds ratio (OR). Results The study included 55 patients (mean age 34.6 ± 10.3 years), 83.6% women, all receiving triple combination therapy with endothelin receptor antagonists (ERAs), phosphodiesterase Type 5 inhibitors, and parenteral prostacyclin analogues. Idiopathic pulmonary arterial hypertension was present in 62%, and 60% were classified as intermediate risk at baseline. Median time from PH‐1 diagnosis to prostacyclin initiation was 8.96 months (IQR 1.88–41.42). At 1 year, complete follow‐up data were available for 49 patients. St. George′s Respiratory Questionnaire scores improved significantly from 49.0 to 36.5 at 1 year and 31.5 at the last follow‐up (p < 0.001). Cardiac index increased from 2.24 to 2.96 L/min/m2 at 1 year (p < 0.001), whereas mixed venous oxygen saturation improved significantly. In survivors, the 6‐min walk test distance increased by 53.5 m, and pulmonary vascular resistance decreased by 3.8 WU. Diffusing capacity for carbon monoxide (DLCO) < 25% was associated with an OR of 7.35 (95% CI: 1.28–41.92; p = 0.015), and tricuspid annular plane systolic excursion to pulmonary artery systolic pressure ratio (TAPSE/PASP) < 0.10 mm/mmHg had an OR of 5.78 (95% CI: 0.64–52.03; p = 0.088). Female sex had an OR of 0.13 (95% CI: 0.02–0.78; p = 0.016). Three‐ and five‐year survival rates were 87.2% and 78.1%, respectively. Conclusion Parenteral prostanoids in patients with PH‐1 demonstrate improvements in hemodynamic variables during clinical follow‐up. A DLCO < 25% and a TAPSE/PASP < 0.10 mm/mmHg were associated with an increased risk of mortality, whereas female sex was identified as a protective factor.