New-onset atrial fibrillation (NOAF) during hospitalization for acute coronary syndrome (ACS) is considered a frequent complication in the setting of acute coronary syndromes.

To discuss the role of admission serum laboratory parameters and hematological indices in the occurrence of atrial fibrillation (AF) during ACS.

A total of 402 patients who were hospitalized with a diagnosis of ACS were prospectively enrolled in the study. The patients were divided into two groups: the NOAF and the non-NOAF group.

In our study, 39 patients develop NOAF during hospitalization for ACS. Mean platelet volume (MPV), neutrophil to lymphocyte ratio (NLR), C-reactive protein (CRP), creatinine and serum uric acid (SUA) were higher in the NOAF group compared with non NOAF group, while Hemoglobin (119±1.8g/l vs. 130±1.9g/l, P=0.001) and red cell counts were significantly lower in the NOAF group than the non-NOAF group. In multivariate regression analysis, age, indexed left atrial volume, left ventricular ejection fraction, increased levels of CRP, MPV, SUA, NLR indepentently predict NOAF.

Admission serum levels of MPV, SUA, CRP, NLR, hemoglobin were found to be independent predictors of NOAF after ACS.