First experience of using two-dimensional speckle-tracking echocardiography to assess the association of left atrial strain with atrial fibrillation after coronary artery bypass grafting

Aim. To assess left atrial (LA) strain parameters in candidates for coronary artery bypass grafting (CABG) and to evaluate their possible relationship with newly diagnosed atrial fibrillation (AF) after isolated CABG. Material and methods . The study Included 70 patients without prior AF (mean age, 65±8 years; men, 80%). Preoperative speckle-tracking echocardiography with an assessment of LA strain was performed. Two following groups were considered: without postoperative AF (POAF) (n=50), with postoperative POAF (n=20). After surgery, daily electrocardiography (ECG), 3-day postoperative continuous ECG monitoring, Holter ECG monitoring on the 4th-5th day after CABG. The median follow-up was 9 (7; 11) days. Results. Postoperative AF developed in 20/70 (29%) patients. Clinical, demographic and intraoperative parameters of CABG in the groups without and with POAF were comparable. Echocardiographic parameters in the studied groups were also equivalent; LA volume (57,0±8,7 vs 60,0±12,1, respectively), LA size (3,9±0,3 vs 3,9±0,2, respectively). Strain analysis showed its significant decrease in the group with POAF compared to the group without POAF: peak atrial longitudinal strain (PALS) (20,4±3,1 vs 27,8±3,0, respectively), ALS early (8,50±1,5 vs 11,8±1,7, respectively), ALS late (-0,2±0,7 vs -1,0±1,0). ROC analysis established the predictive value of PALS as follows: a value of ≤23,0% with a sensitivity of 90% and a specificity of 78% was a predictor of postoperative AF. Conclusion. Conventional echocardiographic predictors (LA size and volume) indicating a high risk of POAF cannot correctly assess the risk of newly diagnosed postoperative arrhythmia. AF after CABG is probably associated with the existing subclinical LA dysfunction as a result of structural abnormalities due to coronary artery disease. Our study showed that a decrease in LA strain parameters is associated with POAF. Further studies are needed to evaluate the contribution of speckle-tracking echocardiography to prediction of POAF.