systemic immune-inflammation index as a predictor of left atrial thrombosis in nonvalvular atrial fibrillation

Background: the systemic immune-inflammation index (sii) has recently been investigated for cardiovascular diseases. we aimed to evaluate the relationship between sii and left atrial thrombosis (lat). methods:this retrospective, case-control study recruited patients with nonvalvular atrial fibrillation (nvaf) who underwent transesophageal echocardiography (tee) for lat detection before cardioversion or catheter ablation at a tertiary hospital between 2012 and 2021. demographic characteristics were obtained from the hospital data system. according to tee findings, the patients were categorized into lat (+) and (-) groups. age, gender, history of chronic diseases, urea, creatinine, albumin, hemogram parameters, the neutrophil-lymphocyte ratio (nlr), the platelet-lymphocyte ratio (plr), sii, the chads₂ score, the cha₂ds₂-vasc score, echocardiographic parameters, antiaggregant-anticoagulant use, and nonparoxysmal atrial fibrillation were included and analyzed. results: the study population consisted of 403 patients, including 228 men (56.6%), at a mean age of 60.84±12.26 years. a high white blood cell count (wbc) (or, 1.26; 95% ci, 1.05 to 1.51; p=0.013), a high sii (or, 1.00, 95% ci, 1.00 to 1.00; p=0.003), and a low ejection fraction (or, 0.95; 95% ci, 0.90 to 0.99; p=0.018) were independent predictors of lat (+). a spontaneous echo contrast (or, 2.43; 95% ci, 1.35 to 4.39; p=0.003) was associated with lat (+). sii values above 693.6 predicted lat (+) with 71.6% sensitivity and 71.7% specificity (auc, 0.77; p<0.001). the predictiveness of sii was similar to that of nlr (0.77 vs 0.74, p=0.093) but higher than plr (0.77 vs 0.67; p<0.001) and wbc (0.77 vs 0.69; p=0.031). conclusion: sii is an independent predictor of lat in patients with nvaf.