Association of the Neutrophil-to-Lymphocyte Ratio, Platelet-to-Lymphocyte Ratio, Lymphocyte-to-Monocyte Ratio, and Monocyte-to-High-Density Lipoprotein Cholesterol Ratio with In Situ Vena Cava Thrombosis

Although several studies have investigated the roles of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and monocyte-to-high-density lipoprotein (HDL) cholesterol ratio (MHR), the findings remain inconclusive and warrant further investigation, particularly regarding their utility in predicting in situ inferior vena cava thrombosis (iIVCT). This study aimed to explore the relationship between composite inflammatory ratios (CIRs) measured within 24 hours after inferior vena cava filter (IVCF) placement and the development of iIVCT, as well as to evaluate their predictive value. A retrospective case-control study was conducted on 154 patients with proximal deep vein thrombosis (DVT) who underwent IVCF implantation between April 2016 and June 2023. Among them, 50 developed iIVCT, while 104 did not. Compared with the non-iIVCT group, patients who developed iIVCT had significantly higher PLR, NLR, LMR, and MHR levels. Multivariate regression analysis showed that NLR, PLR, LMR, and MHR were independently associated with iIVCT, with adjusted hazard ratios of 1.25, 1.16, and 3.32, respectively. Receiver operating characteristic analysis demonstrated that NLR had the highest area under the curve (area under the curve = 0.79), significantly outperforming PLR, LMR, and MHR in predictive accuracy (all <i>p</i> < 0.05, DeLong's test). These findings suggest that CIRs are useful and easily accessible biomarkers for identifying patients at risk of iIVCT following IVCF placement. Notably, NLR emerged as the most effective marker, showing superior discriminatory power compared with the other indicators.