Venous Congestion in Pulmonary Hypertension: A Post Hoc Analysis for Risk Stratification Using a Doppler-based Composite Score in a Tertiary Care Center

INTRODUCTION: Pulmonary hypertension (PH) poses unique challenges in critically ill patients, as systemic venous congestion significantly impacts multiple organ systems. The Venous Excess Ultrasound Score (VExUS) serves as a valuable tool for assessing overall congestion severity but lacks granularity in representing individual organ contributions. Although VExUS incorporates Doppler assessments of hepatic, renal, and mesenteric venous flow patterns, it does not differentiate the specific roles of these systems in clinical outcomes. This limitation highlights the need for a more nuanced approach that considers the individual contributions of organ congestion to overall outcomes, offering greater insight into disease dynamics. OBJECTIVES: This post hoc analysis investigates a composite scoring system that integrates Doppler parameters of the hepatic, portal, and renal veins—components of the original VExUS grading system but assessed as individual entities. The study aims to address VExUS's limitations by offering a refined representation of venous congestion in ICU patients with PH, making it an important tool for risk stratification. MATERIALS AND METHODS: This retrospective post hoc analysis utilized data from a prospective observational study conducted in the ICU of a tertiary care hospital in Chennai. The original study evaluated venous congestion in critically ill patients, focusing on Doppler-based VExUS grading's role in predicting patient outcomes. The current analysis was performed using anonymized data without additional patient interactions. INCLUSION CRITERIA: ICU admissions with PH confirmed via echocardiography, Doppler ultrasound of hepatic, portal, and renal veins within 48 hours, and complete clinical data. EXCLUSION CRITERIA: Patients leaving against medical advice or with incomplete data. A composite score (1–9) was calculated based on validated VExUS criteria for Doppler parameters from hepatic, portal, and renal veins. Mortality and discharge outcomes were analyzed using proportions and the Chi-square test. RESULTS: After excluding one AMA case, 20 patients with composite scores ranging from 3 to 9 (mean: 6.4, median: 6.5) were analyzed. Patients were categorized into Low Risk (composite score ≤ 6, n = 8) and High Risk (composite score > 6, n=10). The Low Risk group had a 90% discharge rate, while the High Risk group exhibited a 50% mortality rate, demonstrating an association between higher scores and adverse outcomes. DOPPLER EVALUATIONS REVEALED SIGNIFICANT VARIABILITY IN VENOUS CONGESTION: Hepatic Veins: 55% showed moderate congestion (S < D flow), 25% had severe congestion with systolic reversal, and 20% had minimal congestion (S > D). Portal Veins: 45% exhibited moderate congestion (pulsatility 30–50%), 30% had severe congestion (>50% pulsatility), and 25% had mild congestion (<30%). Renal Veins: Severe congestion (Grade 3 flow) was observed in 45% of patients. The Chi-square test (p=0.14) and Fisher's Exact Test (odds ratio 0.11) indicated clinically relevant trends but lacked statistical significance. The VExUS grading system had an AUC of 0.86, outperforming the composite scoring system, which had an AUC of 0.74. While VExUS demonstrated superior predictive accuracy, the composite score offered unique organ-specific insights. DISCUSSIONS/CONCLUSIONS: The composite scoring system complements VExUS by addressing its inability to quantify individual organ congestion. By representing specific venous systems, the composite score enables a more detailed understanding of how congestion patterns contribute to clinical outcomes. Its linear scale facilitates trend analysis during patient follow-up and aids in timely escalation of decongestion strategies when early results are lacking. However, this study is limited by its small sample size, arbitrary high-risk categorization, and exclusion of patients with PH without congestion, which may have impacted cohort comparisons. Expanding the study to include such patients could strengthen findings and provide more robust cohorts. While less accurate for outcome prediction than VExUS, the composite scoring system provides critical organ-specific insights, akin to how GCS represents its components. Future research should explore integrating the composite score with VExUS, comparing cohorts with no congestion, low risk, and high risk, and validating its role in broader ICU populations.