Clinical utility of hematological inflammatory indices in predicting pulmonary embolism in patients with lower extremity deep vein thrombosis

Aim: Despite advances in diagnostic strategies, easily accessible biomarkers that can reliably predict pulmonary embolism (PE) in patients with deep vein thrombosis (DVT) are lacking. Recently, systemic inflammatory indices, such as the systemic immune-inflammation index (SII), systemic inflammatory response index (SIRI), and aggregate index of systemic inflammation (AISI), have been investigated as potential prognostic tools. This study aimed to evaluate the predictive value and clinical applicability of these markers in identifying PE in patients with lower extremity DVT.Material and Methods: A retrospective propensity score–matched cohort study was conducted in patients diagnosed with acute proximal lower extremity DVT. Two groups were compared: patients with isolated DVT and those with concurrent DVT and PE were compared. Propensity score matching yielded 290 patients in each group. Novel systemic inflammatory indices derived from hematological parameters (SII, SIRI, and AISI) were evaluated together with neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and traditional biomarkers (C-reactive protein (CRP) and D-dimer). Comparative analyses, logistic regression, and receiver operating characteristic (ROC) curve assessments were performed.Results: Inflammatory indices (NLR, PLR, SII, and SIRI) and conventional biomarkers (CRP and D-dimer) were higher in the DVT and PE group compared to the isolated DVT group (all p