The Value of Intraoperative Transesophageal Echocardiography in Predicting the Incidence of Atrial Fibrillation After Coronary Artery Bypass Grafting: A Prospective Cohort Study

Abstract

Background: Postoperative atrial fibrillation (POAF), the most common arrhythmia following coronary artery bypass grafting (CABG), increases both morbidity and hospital stay. Objectives: To assess the predictive value of intraoperative transesophageal echocardiography (TEE)-derived left atrial (LA) indices for POAF after CABG, with the primary endpoint being the incidence of POAF. Methods: A prospective cohort study was conducted at Mansoura University hospitals from January 2022 to January 2023, including 70 adults undergoing on-pump CABG. Patients were classified into atrial fibrillation (AF, n = 18; 25.7%) and No-AF (n = 52; 74.3%) groups. Comprehensive TEE was performed before and after cardiopulmonary bypass (CPB) to assess LA dimensions, left atrial appendage (LAA) area and flow velocity, left atrial kinetic energy (LAKE), and left atrial ejection force (LAEF). Data were analyzed using multivariable logistic regression to identify independent predictors of POAF. Results: The POAF occurred in 25.7% of patients. The AF group was older (66.6 ± 6.1 vs. 61.1 ± 10.0 years; P = 0.031), with a higher prevalence of hypertension (HTN, 83.3% vs. 53.8%; P = 0.027) and prior myocardial infarction (MI, 77.8% vs. 26.9%; P < 0.001). They exhibited a larger LA transverse diameter (4.21 ± 0.23 vs. 4.08 ± 0.19 cm; P = 0.007) and LAA area (3.66 ± 0.62 vs. 2.84 ± 0.26 cm2; P < 0.001), but lower post-cardiopulmonary bypass (post-CPB) LAA velocity (0.39 ± 0.10 vs. 0.63 ± 0.05 m/s; P < 0.001). Intensive care unit (ICU) and hospital stays were longer (4.0 ± 1.1 vs 3.2 ± 0.9 days; P = 0.002 and 7.9 ± 2.1 vs 5.4 ± 2.0 days; P < 0.001, respectively). Independent predictors of POAF included HTN [odds ratio (OR) 5.32; 95% confidence interval (CI) 1.2 - 23.8; P = 0.029], prior MI (OR 9.40; 95% CI 2.2 - 40.1; P = 0.003), pre-cardiopulmonary bypass (pre-CPB) LA transverse diameter (OR 30.43; 95% CI 2.2 - 42; P = 0.011), and pre-cardiopulmonary bypass end-systolic diameter (pre-CPB ESD, OR 5.10; 95% CI 1.9 - 13.2; P = 0.001). Protective factors were higher post-CPB LA appendage maximum velocity (OR ≈ 0.001; 95% CI 0.01 - 0.004; P = 0.022) and post-CPB left upper pulmonary vein systolic-diastolic ratio (LUPVSDR, OR ≈ 0.001; 95% CI 0.002 - 0.014; P = 0.003). Conclusions: Transoesophageal echocardiography-derived parameters, especially LA enlargement and reduced appendage flow, independently predict POAF after CABG and may guide perioperative prophylaxis.