Transoesophageal echocardiography for prediction of postoperative atrial fibrillation after isolated aortic valve replacement: two-dimensional speckle tracking for intraoperative assessment of left ventricular longitudinal strain

Abstract

Objectives: Recent studies suggested association between impaired left ventricular long-axis function and arrhythmic events early after open heart surgery. This prospective study investigated the predictive value of a depressed intraoperative global longitudinal strain (GLS) for postoperative atrial fibrillation after isolated aortic valve replacement in patients with preserved ejection fraction.

Methods: A total of 107 patients with ejection fraction ≥50% and moderate-to-severe aortic stenosis undergoing isolated aortic valve replacement were enrolled. All patients underwent intraoperative transoesophageal echocardiography before surgical incision (T1) and after closure of the sternotomy (T2) with semiautomated measurement of GLS, and were followed for the occurrence of postoperative atrial fibrillation during the hospitalization.

Results: The incidence of postoperative atrial fibrillation was 37/107 (34.6%). Patients with postoperative atrial fibrillation were associated with increased length of hospitalization and a higher risk of low cardiac output syndrome and pulmonary complications. On univariate analysis, significant risk factors associated with postoperative atrial fibrillation were E/e' ratio, left atrial volume index (LAVi), GLST2 and ΔGLS%. On multivariable analysis, GLST2 (odds ratio: 1.21; 95% confidence interval (CI): 1.06-1.56, P = 0.031) and ΔGLS% (odds ratio: 3.66; 95% CI: 1.85-6.79, P = 0.001) were independent predictors of postoperative atrial fibrillation. The best cut-off values for the prediction were GLST2 >-12.75% and ΔGLS% >19.50%, the latter of which had incremental predictive value for postoperative atrial fibrillation.

Conclusions: A significant reduction of intraoperative GLS provides independent information for predicting postoperative atrial fibrillation in patients undergoing aortic valve replacement, and may help to identify patients who are most likely to benefit from targeted prophylaxis.

Keywords: Aortic valve replacement; Atrial fibrillation; Transoesophageal echocardiography.