Conventional and Two-dimensional Strain Echocardiography in Predicting Postoperative Atrial Fibrillation after Coronary Artery Bypass Grafting Surgery in Shahid Madani Hospital of Tabriz, Iran

Objectives: Atrial fibrillation (AF) is a common complication of heart surgery with favorable short- and long-term outcomes. Preoperative left atrial (LA) dysfunction may be a significant component in identifying patients at risk for postoperative atrial fibrillation (POAF) after coronary artery bypass grafting (CABG (surgery. Advances in imaging technologies and an understanding of AF pathophysiology can lead to more definitive potential therapeutic approaches.  The paper has the aim to present the role of conventional echocardiography and LA two-dimensional (2D) strain. 2D Strain echocardio graphies in assessing LA function in predict POAF after CABG surgery. 
Materials and Methods: In this study, all patients with sinus rhythm who underwent CABG surgery were selected. All the patients had undergone conventional echocardiography and LA 2D-strain echocardiography 24 hours before surgery. In addition to demographic, clinical, and intraoperative features, other assessments, including electrocardiogram (ECG) and Holter monitoring, were recorded. The obtained information was recorded, and the study results were reported using descriptive statistics (mean, standard deviation, and percentage frequency).  A Chi-square test was used to evaluate the qualitative variables, and a t-test was used to compare the quantitative variables. Given the multi-factorial nature of AF, univariate and multivariate methods were used to analyze the data and the effect of STRAIN. In this study, P < 0.05 was considered significant. 
Results: According to the findings, 85 patients (81%) were male with a mean age of 60.26 ± 10.61 years. 50% of the patients underwent off-pump CABG surgery, and 50% underwent on-pump surgery with a mean time of 98.52 ± 22.44 minutes. POAF was seen in 22.9% of patients during hospitalization, and AF's duration was 13.85 ± 14.41 hours. AF patients had higher LA volume index (LAVI) than non-AF patients (p = 0.018). There was no significant difference between the two groups in terms of left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular ejection fraction (LVEF), E/e, E/A,and deceleration time(DT) . Non-AF patients had higher rates of LA reservoir (26.97 ± 6.87 VS. 20.46 ± 4.27, p <0.001), LA contractile (14.98 ± 3.68 VS. 12.76 ± 3.72, p =0.012) and LA global (24.28 ± 6.57 VS. 17.71 ± 4.11, p <0.001) than AF patients. The results of the multivariate logistic regression showed that LAVI (p= 0.014) and LA global (p = 0.027) were significant predictors of AF detection. Thus with increasing LAVI, the probability of developing AF increases, and with decreasing LA global, this probability decreases. 
Conclusions: Compared to conventional echocardiography, 2D-strain echocardiography is a more effective diagnostic tool in predicting the possibility of post-CABG AF.