Real-World Safety and Clinical Outcomes of Macitentan in Asian Patients with Pulmonary Arterial Hypertension: A Prospective Multicenter Study

Background and Objective Macitentan is approved for treating pulmonary arterial hypertension. However, the real-world evidence of macitentan use is limited. Therefore, we evaluated the safety and clinical outcomes of macitentan use in clinical practice under a post-marketing surveillance. Methods Patients with pulmonary arterial hypertension receiving macitentan treatment were prospectively and consecutively enrolled from 2014 to 2020 at 50 medical centers in Korea. Safety and clinical outcomes were monitored from baseline to the nearest timepoint of 24 weeks after macitentan initiation. The adverse events and adverse drug reactions were identified. Changes in the World Health Organization functional class were assessed as the primary clinical outcome, which was used to estimate the final effectiveness (both improved and maintained). Factors associated with safety and final effectiveness were identified. Results Among 474 patients enrolled in the study, 467 and 440 were included in the safety and clinical outcome analyses, respectively. Dyspnea, nasopharyngitis, and worsening pulmonary arterial hypertension were the most frequent adverse events with incidences of 5%, 3%, and 3%, respectively. The final effectiveness rate was 93%. Older age (adjusted odds ratio [aOR] = 1.021, p = 0.003) and higher level (III vs II) of baseline World Health Organization functional class (aOR = 1.784; p = 0.022) were significantly associated with a higher adverse event occurrence. Younger age (aOR = 0.947; p = 0.001) and shorter disease duration (aOR = 0.991; p = 0.010) were significantly associated with positive final effectiveness. Conclusions This real-world study demonstrated the safety and clinical outcomes of macitentan use in Korean patients with pulmonary arterial hypertension. Macitentan was well tolerated and significantly effective with no new safety concerns during the 24 weeks.