Preoperative Platelet-to-Lymphocyte Ratio Is Not Associated With Postoperative Atrial Fibrillation

Background. Postoperative atrial fibrillation (POAF) is a common complication after coronary artery bypass grafting (CABG) and is associated with increased short-term and long-term mortality. While the precise etiology of POAF remains unclear, inflammation is a known contributing factor. Preliminary studies have suggested that an elevated preoperative platelet-to-lymphocyte ratio (PLR), an inexpensive and readily available novel inflammatory biomarker, may be associated with increased incidence of POAF after CABG. This study sought to further investigate this hypothesis. Methods. The study cohort included all patients undergoing isolated CABG, with no prior history of arrhythmia, who were operated on between August 1, 2010, and December 31, 2018, at a major Australian tertiary center (n = 1457). Patients were divided into low (86) or high (>= 86) PLR groups based on an optimal cutoff derived from receiver-operating characteristic curve analysis. The incidence of POAF was then compared. Categorical variables were analyzed using the chi-square test and continuous variables using logistic regression. Results. Of 1457 patients, 495 (34.0%) developed POAF. There was no statistically significant difference in the incidence of POAF between patients in the high-PLR and low-PLR groups (34.8% vs 31.0%; P = .22). Using multivariable logistic regression analysis, high PLR was not independently associated with POAF (odds ratio, 1.04; P =.78). Conclusions. Elevated preoperative PLR is not independently associated with POAF in patients undergoing isolated CABG. The findings of this study differ from those of 2 previous smaller studies. (C) 2020 by The Society of Thoracic Surgeons