What Should Be the Definition of “Remission” in Pulmonary Arterial Hypertension?

The recent advent of sotatercept, a novel agent targeting the activin signaling pathway, has significantly improved the treatment of pulmonary arterial hypertension (PAH), with the potential to modify the underlying disease process rather than merely provide symptomatic relief.This paradigm shift has reinvigorated discussions on new therapeutic goalsparticularly the possibility of achieving PAH remission.In oncology and chronic inflammatory diseases, remission is a well-established concept, defined either by the complete disappearance of disease in malignant conditions or by the sustained absence of clinical activity in non-malignant disorders.In contrast, applying the concept of remission to PAH remains challenging, as direct assessment of pulmonary vascular remodeling is not currently feasible in clinical practice.Therefore, the definition of remission must rely on