Abstract
Pulmonary arterial hypertension (PAH) in intermediate-risk patients poses a challenge for clinicians, particularly in determining the optimal timing for escalating pharmacological treatment. We conducted a multicenter cross-sectional study that analyzed data from the Colombian Pulmonary Hypertension Network (HAPredCO) on patients diagnosed with PAH. Participants were stratified into low- and high-intermediate risk groups using the four-level ESC/ERS score, which incorporates optimized cutoff values for WHO functional class (WHO FC), the 6-min walk test (6MWT), and N-terminal pro-brain natriuretic peptide (NT-proBNP)/brain natriuretic peptide (BNP) concentration. A bivariate analysis was conducted to compare study variables at baseline and during clinical follow-up. Additionally, a survival analysis was performed using Kaplan-Meier curves to compare outcomes between the intermediate-risk groups. A total of 175 patients were analyzed, with a mean age of 44.85 years (SD 15.5), of which 86% (150/175) were women. In the baseline, a total of 75% (131/175) were classified as intermediate-low-risk. In clinical follow-up, 40% (61/154) were classified as intermediate-low-risk, 21% (32/154) were classified as intermediate-low-risk, 23% (35/154) were classified as intermediate-low-risk, and 16% (26/154) as intermediate-high-risk. At baseline, WHO FC III was 61% (107/174), compared to 35% (56/154) at follow-up (p = 0.083). The use of bosentan decreased from 36% (63/175) to 28% (46/154) (p < 0.001), while ambrisentan increased from 18% (31/175) to 30% (47/154), and macitentan increased from 25% (44/175) to 36% (57/154). The use of parenteral prostanoids and selexipag increased by 20% (4% vs. 24%) and 3% (1% vs. 4%) during clinical follow-up, respectively. Overall survival at 1 year of follow-up was 96%, at 2 years 92%, and at 3 years 88%. The survival rates at 1, 2, and 3 years were 98%, 95%, and 90% in the intermediate-low-risk group, and 90%, 80%, and 80% in the intermediate-high-risk group. In this real-world study of PAH in the Colombian HAPredCO registry, the median survival in the intermediate-low-risk group was slightly higher than in the intermediate-high-risk group. At baseline, most patients were classified as intermediate-low-risk. However, during clinical follow-up, risk distribution changed, with a notable proportion shifting across different risk categories.