Predictors of Atrial Fibrillation Developing in Hospital Stage After Coronary Artery Bypass Surgery

Aim    To identify independent predictors associated with in-hospital atrial fibrillation (AF) following coronary artery bypass grafting (CABG).Material and methods     The study included 80 patients (88.75 % men) who had elective CABG surgery at the Sklifosovsky Research Institute of Emergency Medicine. Based on the development of AF during the hospital stage of treatment (up to 10 days after CABG surgery), patients were divided into two groups. The group with AF consisted of 19 patients, and the group without AF consisted of 61 patients. All patients underwent electrocardiography (ECG), transthoracic echocardiography (EchoCG) with calculation of the left ventricular (LV) geometry type, and assessment of operational indexes. During surgery, biopsy of a part of the right atrial (RA) appendage was taken from 61 patients to verify the severity of myocardial fibrosis on a four-score scale where 0 is no interstitial fibrosis, 1 is slight fibrosis, 2 is moderate fibrosis, and 3 is severe fibrosis.Results    All included patients had a low risk of developing postoperative complications according to the EuroSCORE II scale. According to EchoCG data, patients with AF had significantly higher ratios of left ventricular myocardial mass to body surface area (LVMM / BSA) (p = 0.0006) and of left atrial volume to body surface area (LA volume / BSA), p = 0.008). The distribution of patients by type of LV geometry was as follows: in the group with AF, 52.63 % (n=10) of patients were diagnosed with concentric LV hypertrophy (LVH) whereas in the group without AF, the majority of patients (83.60 %, n=51) had normal LV geometry and concentric LV remodeling (LVR) (p<0.0001). According to the results of histological study, patients of the AF group more frequently had moderate and severe interstitial fibrosis in the AF appendage (p = 0.003). After multivariate regression and ROC analysis, the predictive value remained for concentric LVH (p=0.002), LVMM / BSA ratio ≥97 g / m2 (p=0.006), LA volume / BSA ratio ≥ 34.4 ml / m2 (p=0.04), and for RA appendage interstitial fibrosis score ≥2 (p=0.004). Based on the identified predictors, a regression model was developed to predict the development of AF at the hospital stage after CABG (p<0.0001). The sensitivity and specificity of the model were 86.67 % and 78.26 %, respectively.Conclusion    In patients at low perioperative risk, the LVMM / BSA ratio ≥97 g / m2, the LA volume ratio / BSA ≥34.4 ml / m2, a RA appendage interstitial fibrosis score ≥2, and the presence of LVH were independent predictors of the development of AF at the hospital stage after CABG operation.Conclusion In patients at low perioperative risk, a LVMM / BSA ratio ≥97 g / m2, a LA volume / BSA ratio ≥34.4 ml / m2, a RA appendage interstitial fibrosis score ≥2, and the presence of LVH were independent predictors of the development of AF at the hospital stage after CABG.