Clinical efficiency of macitentan in patients with pulmonary hypertension. our experience in Argentina

Introduction: Pulmonary Hypertension (PH) is a disease characterized by an increase in pulmonary resistances that leads to right heart disfunction, heart failure and death. There are multiple associated pathophysiological mechanisms that are used as therapeutic targets. Macitentan (M) is a non‐selective inhibitor of endothelin receptors, which has demonstrated clinical benefits in morbidity and mortality in a Phase III study. (Macitentan and Morbidity and Mortality in Pulmonary Arterial Hypertension SERAPHIN trial). Objective: To describe the clinical efficacy in our population of Macitentan in PH patients. Material and methods: A prospective, consecutive, open, phase IV registry of patients with PH who started treatment with M (Opsumit MR) in Argentina, from March 2015 to November 16, was performed. We included those p who received M for at least 6 months or presented an event. Baseline characteristics, functional class (FC), 6‐minute gait test (TM6M), adverse effects and survival were determined according to the recommendations of the national and international guidelines, at baseline and at 6 month. Clinical efficacy was determined by the improvement in FC from III‐IV (advanced) to FC I‐II (not advanced), and improvement in 6MWT> 15%. The data was loaded into an Excel database and evaluated with the Bioestat 5.0 program. The normality of the sample was analyzed by the D'Agostino‐Pearson test. In relation to the distribution, the t test was used for quantitative variables, Chi2 for qualitative and McNemar test for paired variables. A p value of <0.05 was defined as a significant difference between baseline and 6 months. Results: We included 151 p, 74% women, the average of age was 46 years (28‐63) and 98.4% had HP group 1. 98.6% received M 10 mg and 1.4% 5 mg. At baseline, functional class evaluation presented the following distribution: FC I 2.4%, II 19.4%, III 65.3% and IV 12.9% (advanced FC 78.2%). Themean baseline TM6M was 321 m (250‐400). At 6 months FC I was 13.5%, II 62.2% and III 24.3% (advanced FC 24.3%), with significant statistical benefit (p <0.001). The mean TC6M reached 397.2 m (320‐467), an increase of 24%, with a significant difference (p <0.0001, 95% IC‐533‐51.6). Conclusion: In our PH registry, administration of Macitentan was associated with a significant benefit in achieving the objectives of functional class improvement and the distance reached in the 6MWT (76 meters), at 6 months. These data are in agreement with those obtained in the randomized study SERAPHIN.