Risk stratification, prognosis, and survival in a pulmonary arterial hypertension cohort in Latin America. A multicenter study.

Background: Pulmonary arterial hypertension (PAH) guidelines suggest that achieving a low-risk profile should be the treatment goal. Our aim was to assess a risk assessment strategy based on three non-invasive variables from the ESC/ERS 2015 guidelines in a Latin American cohort.

Methods: 92 incident patients (mean [SD] age 47, 77% female, 53% idiopathic PAH) were included in this retrospective, multicenter study. Patients were stratified at baseline and at early follow-up, within the first year, using three non-invasive variables (WHO functional class, 6-minute walking distance, BNP/NT-proBNP) from the ESC/ERS 2015 risk assessment instrument. Median (IQR) follow-up was 3.11 years (3.01 years).

Results: At baseline assessment, 25% of patients were at low risk, 61.9% at intermediate-risk, and 13% at high-risk. At early follow-up (median 9.5 months), 56.5% of patients were at low-risk, 40.2% at intermediate-risk, and 3.2% at high-risk (p<0.001 vs. baseline). According to risk stratification at early follow-up, one, three and five-year overall survival was 100% in the low-risk group (no deaths at five-year follow-up), and 100%, 84% (95% CI: 72-98%), and 66% (95% CI: 48-90%) respectively in the intermediate-risk group, p = 0.0003. Mortality in the high-risk patients at early follow-up was 1/3 (33.3%). One, three, and five-year event-free survival (death or transplant or first hospitalization due to worsening PAH) based on early follow-up risk assessment was higher in the low-risk group, p = 0.0003.

Conclusion: Our study validates a risk assessment strategy based on three non-invasive variables and confirms that early achievement of a low-risk profile should be the treatment goal.