<scp>CMR</scp> ‐derived left ventricular pressure‐volume loops enhance individualized assessment of disease severity and prognosis in pulmonary arterial hypertension in adults

In pulmonary arterial hypertension (PAH), increased pulmonary vascular resistance (PVR) causes right ventricular pressure overload and left ventricular (LV) underfilling. We investigated LV mechanics and their prognostic value in PAH using cardiovascular magnetic resonance (CMR)-derived LV pressure-volume (PV) loops. We included 96 patients (median age 64 years, 70% women) with PAH and clinically indicated CMR between 2003 and 2025, and 32 age- and sex-matched healthy controls. CMR-based LV PV-loops were computed. Right heart catheterization, brachial blood pressure, treatment, and time of death or lung transplantation were retrieved from medical records. Patients demonstrated lower stroke work (SW) and ventricular efficiency (VE), and higher contractility (Ees), arterial elastance (Ea), ventriculo-arterial coupling (VAC), and energy per ejected volume (EEV) than controls. SW and Ea correlated with PVR, VE and VAC correlated with diastolic transpulmonary gradient (p < 0.001). After 3 years median follow-up, 64 (68%) patients died or underwent lung transplantation. Supra-median SW was associated with better prognosis in patients ≤55 years. Exploratory data suggested increasing SW in treatment responders only. CMR-based PV-loops showed LV mechanics alterations in PAH. SW, VE, Ea, and VAC correlated with disease severity. SW predicted survival in patients ≤55 years and might help monitor treatment response.