Venus excess lung ultrasound (VExUS) score for the estimation of right atrial pressure

Background The venous excess ultrasound (VExUS) score is a four-staged validated protocol which evaluates the presence and severity systemic venous congestion examining the inferior vena cava (IVC) diameter and collapsibility, and the flow in the hepatic vein (HV), the portal vein (PV), and the interlobar renal veins (IRVs). The purpose of our study was to determine if VExUS score predicts the right atrial pressure (RAP) in patients undergoing right heart catheterization. Methods In this perspective study, all consecutive patients undergoing indicated right heart catheterization (RHC) from September to December 2024 in two Italian centres underwent echographic scan examining IVC, HV, PV and IRVs within one hour from RHC. Results We enrolled 72 patients (46% women, mean age 57±17 years). After a complete assessment, the patients received the following diagnosis: 57 (79%) pulmonary arterial hypertension, 2 (3%) post-capillary pulmonary hypertension (PH), 3 (4%) PH associated with lung disease, 5 (7%) chronic thrombo-embolic PH, 2 (3%) PH with unclear and/or multifactorial mechanisms, 3 (4%) normal haemodynamics. The VExUS index was evaluated as a predictor of RAP, showing a significant association (Kruskal-Wallis χ² test, p < 0.001). The receiver operating characteristic (ROC) analysis yielded an AUC of 0.81, indicating good discriminative ability (figure 1). The optimal VExUS cutoff of 1 was identified, achieving a sensitivity of 0.83 and a specificity of 0.70 for predicting RAP >8 mmHg. Figure 2 represents the distribution of RAP across VExUS levels. Conclusion Our findings suggest that VExUS is a valuable non-invasive tool for assessing venous congestion and for estimating right atrial pressure.