Survival and Hemodynamic Effects of Parenteral Prostanoids in High-Altitude Group 1 Pulmonary Hypertension: A...

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.

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).

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.

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.