Pulmonary arterial hypertension (PAH) is a progressive disease characterized by increased pulmonary vascular resistance and pressure, leading to right ventricular failure and reduced survival. Estimated incidence and prevalence are approximately 6 and 48–55 cases per million adults, respectively [1,2], and the disease remains associated with poor long-term survival, with 5-year survival rates around 50–60% despite advances in targeted therapies [3–5]. Although right heart failure represents the leading cause of death in patients with PAH [6,7] —supporting the central prognostic role of right ventricular function— approximately 13–26% of patients experience sudden death (SD) [8–10], whose underlying determinants remain poorly understood.
