Evaluating inferior vena cava reflux and RV/LV ratio as predictors of acute pulmonary thromboembolism severity

PURPOSE: This study aimed to evaluate the predictive value of inferior vena cava (IVC) reflux and the right ventricle to left ventricle ratio (RV/LV ratio) in risk stratification of acute pulmonary thromboembolism (APTE) patients. METHODS: In this retrospective, cross-sectional study, eighty-six patients diagnosed with APTE underwent computed tomography pulmonary angiography (CTPA). The pulmonary arterial obstruction index (Qanadli score) was evaluated by an experienced radiologist, along with the RV/LV ratio and IVC reflux grading (1-6) based on CTPA. Correlations between the Qanadli score, IVC reflux grade, and RV/LV ratio were analyzed. Linear regression was performed after confirming regression assumptions. Additionally, IVC reflux grade and Qanadli score were compared between patients with RV/LV ratios below and above 0.9. RESULTS: The mean Qanadli score was 7.20 ± 8.04. A significant correlation was found between the Qanadli score and IVC reflux grade (r = 0.601, p < 0.001), whereas no significant correlation was observed between the Qanadli score and RV/LV ratio (r = 0.131, p = 0.230). Further analysis demonstrated a significant linear association between the Qanadli score and IVC reflux grade, with a regression coefficient of 3.98 ± 0.55 (p < 0.001) and an adjusted R² of 0.38. However, patients with an RV/LV ratio > 0.9 did not show a significant difference in IVC reflux grade (p = 0.176) or Qanadli score (p = 0.439). CONCLUSION: Our study highlights IVC reflux as a potential valuable imaging marker for assessing APTE severity, while also pointing out the limitations of relying solely on the RV/LV ratio for risk stratification.