Association between complete blood cell count-derived inflammatory indices and left atrial thrombus in patients with nonvalvular atrial fibrillation: a cross-sectional study

Background Systemic inflammation plays a key role in thrombogenesis, yet the value of routine complete blood count-derived inflammatory indices for predicting left atrial thrombus (LAT) in patients with non-valvular atrial fibrillation (NVAF) remains unclear. Methods In this cross-sectional study of 623 patients with NVAF (59 with LAT, 9.5%), we evaluated eight inflammatory indices for their association with LAT, using multivariable logistic regression and receiver operating characteristic (ROC) curve analysis. Results Among the inflammatory markers analyzed, neutrophil-to-lymphocyte ratio (NLR), neutrophil-to-mean platelet volume ratio (NMR), systemic immune-inflammation index (SII), systemic inflammation response index (SIRI), and pan-immune-inflammation value (PIV) were significantly associated with LAT risk after multivariable adjustment. ROC curve analysis indicated moderate predictive accuracy for these five indices, with area under the curve values ranging from 0.582 to 0.601, though no significant differences were found between them. Other indices, including monocyte-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and white blood cell-to-mean platelet volume ratio, showed no significant predictive value. Conclusion NLR, NMR, SII, SIRI, and PIV are readily accessible and cost-effective inflammatory biomarkers that show association with LAT risk in NVAF patients. These indices may offer supplementary information for risk stratification in clinical practice. Their potential to guide more intensive assessment or therapeutic strategies requires further prospective validation.