Switch from Bosentan to Macitentan in Adult Outpatients with Pulmonary Arterial Hypertension: A Real-World Study

MARIA TERESA POLITI; NICOLAS CARUSO; JAVIER LESCANO; JUAN MARIA FARINA; DAMIAN NESTOR SPAGNUOLO; RAUL FERREYRA; BORTMAN, GUILLERMO

San Diego

Congreso; THE INTERNATIONAL SOCIETY FOR HEART AND LUNG TRANSPLANTATION Annual Meeting and Scientific Sessions; 2017

THE INTERNATIONAL SOCIETY FOR HEART AND LUNG TRANSPLANTATION

Purpose: Macitentan is a dual endothelin receptor antagonist approved byFDA in 2013 for the treatment of symptomatic pulmonary arterial hypertension(PAH) in adult patients. It has shown clinical efficacy and possiblyless interactions than bosentan. However, documented clinical experience inswitching from bosentan to macitentan in real-world settings is still scarce.Methods: We designed a prospective cohort study to evaluate the clinicaleffectiveness and safety of switching from bosentan to macitentan inadult outpatients with PAH. Patients over 18 years-old that were in WHOfunctional class II-III/IV and receiving bosentan 250 mg/day plus sildenafil75-150 mg for over a period of 6 months were asked to take part of thisstudy. Patients who agreed to participate were switched to macitentan 10mg/day plus the same dosis of sildenafil in combination. WHO functionalclass, baseline 6-minute walk test distance and Borg Dyspnea Score wereevaluated. The primary clinical endpoint was the prevalence of patients inWHO functional class III/IV after drug switch. The primary safety endpointwas change in hemoglobin values.Results: Between March 2015 and February 2016, 21 adult outpatients withPAH were included in this study. 6 months after switching from bosentan tomacitentan the proportion of patients in WHO functional class III/IV wasreduced five-fold (47.6 to 9.5%; p < 0.010) and mean 6-minute walk testdistance increased significantly (348.1±75.6 to 384.0±63.7 meters; p< 0.001).Laboratory endpoints also showed improvement: median brain natriureticvalues (98 [68-132] to 78 [62-120] pg/ml; p< 0.010) and mean uric acid levels(6.1± 0.9 to 5.7±0.6; p< 0.001) were significantly reduced. Hemoglobinvalues did not show significant changes (40.2±0.7 to 39.8±0.6; p= 0.100)while liver enzymes decreased significantly (AST: 40.7 to 27.9 IU/l; p