Inflammation plays a key role in the initiation and progression of atrial fibrillation (AF). We developed a novel systemic inflammation score (SIS) based on integration of biomarkers used routinely in clinical settings. We aim to explore the association between SIS and AF.

A matched case-control study with 376 pairs of AF cases and controls was performed using a propensity score matching system. The SIS was developed by integrating albumin (ALB), neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), and lymphocytes to monocytes ratio (LMR). Univariate and multivariate analyses were performed to examine the association of each marker and SIS with AF.

The conditional multivariate logistic regression analysis showed that elevated levels of ALB and LMR were significantly associated with decreased risk of AF with an OR of 0.74 (95% CI: 0.65, 0.85) and 0.73 (95% CI: 0.64, 0.83), respectively. Patients with elevated SIS had a significantly higher risk of AF. Compared to the patients with SIS equal to 1, the patients with SIS equal to 3 and 4 had an OR of 2.16 (95% CI: 1.40 3.32), and 2.55 (95% CI: 1.66, 3.92), respectively. The SIS was positively correlated with left atrial diameter and right atrial diameter in patients with AF.

In conclusion, this study provides further clinical epidemiological evidence that systemic inflammatory status was correlated with AF. The SIS, as an index to evaluate the intensity of systemic inflammatory status, could be useful for early prediction of AF development and understanding of AF mechanism.