Clinical Efficiency of Macitentan in Patients with Pulmonary Hypertension. Real World in Argentina

Background: Pulmonary Arterial Hypertension (PAH) is a chronic and progressive disease characterized by an increase in the pulmonary pressure and pulmonary vascular resistance that leads to high morbidity and mortality. Macitentan is an endothelin receptor antagonist (ERA), that has shown benefit in terms of morbidity and mortality (as a composite endpoint) in a randomized controlled trial (SERAPHIN), but information regarding the use of this drug in the daily clinical practice is limited in our region. Objective: To describe clinical outcomes in patients with a diagnosis of Pulmonary Hypertension (PH) treated with Macitentan in Argentina. Methods: Retrospective, observational study including adult patients with a diagnosis of PH, confirmed by right heart catheterization, who were treated with Macitentan in Argentina between March 2015 and April 2019. All the information was obtained from a designed database. Patients receiving Macitentan for at least 9 months were included and the clinical outcome was defined as improvement in the functional class (FC) from advanced (III/IV) to non-advanced (I/II) and in the 6-minute walk test (6MWT). Results: 126 patients with a median age of 46 years, with a predominance of female gender (74%) and PH group 1 (97%) were included. Before starting Macitentan, 78.9% of patients had advanced FC and the average number of meters walked in the 6MWT was 311 (SD 121 m). At six and twelve months, the percentage of patients in advanced FC was significantly reduced and the 6MWT distance increased to 360 and 361 meters respectively, both results with statistically significant benefit (p<0.001). Conclusions: In our cohort of patients, treatment with Macitentan was associated with a significant clinical benefit, with improvement both in FC and in the 6MWT distance at 6 and 12 months. This information is consistent with the results of the SERAPHIN study, and it is the first contribution on the use of this drug in a real-world scenario in our region.