Evolution of Patients with Pulmonary Arterial Hypertension Starting Macitentan After the Discontinuation of Other Endothelin-Receptor Antagonists: Results of a Retrospective Study.

Background: Macitentan is the latest endothelin-receptor antagonist (ERA) approved for the treatment of pulmonary arterial hypertension (PAH), presenting enhanced properties over previous ERAs.

Objective: We describe the clinical and echocardiographic evolution of patients with PAH who started macitentan after discontinuing bosentan/ambrisentan.

Methods: This was a retrospective series of patients with different etiologies who started macitentan after the suspension of other ERAs under routine clinical practice at five Spanish hospitals. World Health Organization functional class (WHO-FC), 6-min walk distance (6MWD), levels of N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and cardiac imaging data were collected and described at baseline (before macitentan initiation) and after 3, 6, and 12 months, when available.

Results: In total, 12 patients (ten women; mean age 65.63 ± 13.27 years) were observed. At baseline, most patients were receiving concomitant PAH medications, and five patients were classed as WHO-FC III. After 3 months of macitentan treatment, WHO-FC had improved in four patients, 6MWD increased in eight patients, and NT-proBNP levels and right atrial area were lowered in seven and eight patients, respectively. Similar results were observed after 6 and 12 months. Macitentan was well-tolerated, with no PAH hospitalizations, septostomies, transplants, or deaths registered.

Conclusions: Our results suggest that switching to macitentan in patients with PAH who discontinued bosentan/ambrisentan was well-tolerated and effective. Further studies are needed to confirm these observations.