Abstract 4361924: Right heart dimensions and pulmonary arterial wedge pressure in pulmonary arterial hypertension: exploring a controversial relationship

Introduction: Pulmonary capillary wedge pressure (PCWP) provides an indirect estimate of left ventricular (LV) end-diastolic pressure.Its assessment is crucial in evaluating pulmonary hypertension. Hypothesis: Recent research indicates a correlation between advanced pulmonary arterial hypertension (PAH) and worsened pulmonary congestion, suggesting a paradoxical relationship between right ventricular (RV) dysfunction and elevated lung water content. However, the correlation between PCWP and cardiac chamber size or RV afterload remains unclear in PAH. Aim: This study aims to evaluate the correlation between PCWP, right and left ventricular dimensions, and right ventricular overload, in a large, multicenter cohort of patients with PAH. Methods: A post-hoc analysis was conducted from 401 idiopathic, heritable, or PAH associated with connective tissue disease patients, prospectively included in the ULTRAsound RIGHt venTricular eVALUation (ULTRA RIGHT VALUE) registry. This is the first multicentre, observational registry, involving 8 European expert referral PAH centers, characterized by centralized echocardiography reading with high-quality data imaging, according to FDA/EMA regulatory standards. Each patient received a comprehensive clinical, echocardiographic, and hemodynamic evaluation. All echocardiographic images were electronically transmitted to a core laboratory at Sapienza University of Rome for standardized evaluation. Echocardiographic studies were performed on average 0±31 days from RHC. Correlations between PCWP and ventricular dimensions were assessed using Pearson’s correlation coefficient (r). Results: From January 2022 to December 2023, the study included 401 patients with prevalent PAH. The mean age was 52±17 years. The majority of patients were female (275 patients,68%), with idiopathic PAH (244 patients,61%). One hundred thirty (32.4%) of patients had at least one cardiometabolic comorbidity. Two hundred eighty-nine (72%) patients completed echocardiographic studies within 24 hours after RHC. No significant correlations were observed between PCWP and RV end-diastolic area (r=0.07;p=ns), LV end-diastolic index (r=-0.06;p=ns), and LV end-diastolic area (r=-0.004;p=ns) at baseline. Additionally, no correlation was found between delta PCWP and delta PVR (r=-0.06;p=ns) in 150 patients (37%) from baseline to follow-up. Conclusion: Increased PVR and echocardiographic data of cardiac chamber size from patients with PAH were not associated with increased PCWP