The use of systemic immune-inflammation index to predict new onset atrial fibrillation in the context of acute coronary syndrome

Aim The objectives of this study were to determine the relationship between the systemic immune-inflammation index (SII) and new onset atrial fibrillation (NOAF) in patients with acute coronary syndrome (ACS), and to assess the use of this relation, if any, to predict NOAF in the context of ACSMaterial and Methods A total of 622 patients diagnosed with ACS and followed up between September 2019 and September 2021 were included in this study. 35 (5.6 %) of these patients, suffering from NOAF, were designated as the patient group, and the remaining 577 (94.4 %) patients were designated as the control group. SII was calculated with the formula [ (platelet count x neutrophil count) / lymphocyte count] in all patients.Results SII was significantly increased in the NOAF group [1641 (778-4506) vs. 660 (54-2835); p<0.001. The multivariable logistic regression analysis revealed that SII [OR: 1.002, 95 %CI: 1.001-1.002, p<0.001] is one of the independent predictors for NOAF, in addition to age (p=0.003) and left atrium size (p=0.005).Conclusion The SII index is an independent predictor of NOAF in ACS patients. This index can be used as an easily accessible value in the clinic. Assessment of risk factors for NOAF may permit early treatment and close follow-up of patients with poor prognosis who may develop AF.