Conceptual Reconsideration of the Classification of Pulmonary Hypertension: From 5 Groups to 2 Groups.

Pulmonary hypertension (PH) is a hemodynamic condition arising from heterogeneous, often overlapping triggers. Although the etiology-driven 5-group classification provides an essential framework for disease definition and research standardization, it is frequently challenged in real-world practice, where cardiopulmonary multimorbidity is common and often delays therapeutic decision making. Here, we propose a complementary, treatment-oriented binary framework that stratifies pulmonary hypertension by dominant structural mechanisms: pulmonary microvasculopathy versus pulmonary large-vessel stenosis. Although anatomically grounded, this distinction primarily reflects pathophysiological processes, hemodynamic behaviors, and therapeutic responsiveness. Rather than supplanting current classifications, it highlights lesion-level features directly relevant to therapeutic strategy. We outline pragmatic diagnostic pathways integrating anatomical imaging, hemodynamic confirmation, and systematic evaluation of cardiopulmonary comorbidities, emphasizing early identification of potentially revascularizable large-vessel disease, where surgical or endovascular intervention may yield substantial and durable clinical benefit. This pathophysiology-driven perspective aims to simplify frontline decision making, reduce diagnostic delay, and support treatment precision across diverse clinical settings.