Left Atrial Strain to Predict Postoperative Atrial Fibrillation in Patients Undergoing Off-pump Coronary Artery Bypass Graft

Abstract

ObjectivePostoperative atrial fibrillation (POAF) is associated with increased morbidity, mortality, and length of stay. The objective of this study was to assess the utility of left atrial strain (LAS) to predict POAF in patients undergoing off pump coronary artery bypass grafting (OPCABG). DesignRetrospective Observational Study. SettingTertiary Care Level Hospital. Participants103 undergoing OPCABG. InterventionsNone. Measurements and ResultsIn addition to comprehensive TTE, LAS was measured for reservoir (R), conduction (CD), and contraction (CT) components. The POAF was defined as new electrocardiography evidence of AF requiring treatment. Logistic regression was done to assess the factors associated with POAF. The diagnostic accuracy of variables in predicting POAF was assessed by ROC analysis.POAF was documented in 24 (23.3%) patients. There was no difference in EF, average GLS and proportion of LVDD grades between patients with POAF and patients without POAF. All the three components of LAS: LAS R (19.2 ± 4.7 vs 23.5 ± 4.8; p<0.001), LAS CD (8.9 ± 3.7 vs 12.3 ± 4.8; p=0.1) and LAS CT (10.3 ± 3.9 vs 12.1 ± 4.1; p=0.04) were significantly lower among patients with POAF as compared to patients without POAF respectively. According to univariate analysis, all components of LAS were found to be statistically significant predictors of POAF. On multivariate analysis, only age (OR=1.08; p=0.025) and LAS R (OR=0.84; p=0.004) were independently associated with POAF. The LAS R was a better predictor of POAF with AUC of 0.758, than LAS CD (AUC=0.67) and LAS CT (AUC=0.62). The LAS R had optimal cut-off of 23% with sensitivity of 95.8% (C.I. 78.9%- 99.9%) and specificity of 49.4% (37.9%- 60.9%) to predict POAF. ConclusionsLAS R is significant predictor of POAF and its use can be recommended for screening of OPCABG patients at high risk of POAF.