Left atrial booster-pump function as a predictive parameter for new-onset postoperative atrial fibrillation in patients with severe aortic stenosis

Postoperative atrial fibrillation (POAF) is associated with increased risk of embolic events and heart failure, but its associated factors remains unknown. Left atrial (LA) subclinical mechanical dysfunction caused by the acute stress of surgery may be clinically manifested as POAF. The purpose of our study was therefore to test the hypothesis that preoperative LA subclinical myocardial dysfunction is a potential predictor of development of POAF in patients with aortic stenosis (AS). We studied 27 patients with severe AS undergoing aortic valve replacement (AVR) with left ventricular (LV) ejection fraction of 63 ± 11 %. All patients were in sinus rhythm and had no history of atrial fibrillation (AF). LA reservoir (SR-LAs), conduit (SR-LAe), and booster-pump (SR-LAa) functions were determined as the averaged global LA speckle-tracking longitudinal strain rates from apical four- and two-chamber views. POAF, defined as any episode of AF within 30-day after AVR, was observed in 15 patients (56 %). There were no differences in clinical characteristics, LA and LV volumes, and global LV function between patients with and without POAF. Multivariate logistic regression analysis identified SR-LAa as the only independent predictor of POAF. Furthermore, SR-LAa >0.79 s⁻¹ predicted POAF with 60 % sensitivity, 92 % specificity, and area under the curve of 0.828 (p < 0.0001). Of the 15 patients with POAF, one developed paroxysmal AF during long-term follow-up. In conclusions, SR-LAa helped to detect subtle LA booster-pump dysfunction and was associated with new-onset POAF in patients with severe AS. These findings may be useful for risk stratification and management of such patients.