Preoperative interatrial block is associated with postoperative atrial fibrillation after cardiac surgery

Objectives: Atrial fibrillation is common complication after heart surgery potentially leading to chronic atrial fibrillation, heart failure, and mortality. The aim of this study was to explore the relationship between preoperative interatrial block and the occurrence of postoperative atrial fibrillation.

Methods: Perioperative 12-channel ECGs of patients in sinus rhythm, scheduled for heart surgery including bypass and/or valve surgery were analysed. Patients with pre-existing atrial fibrillation, amiodarone therapy, atrioventricular block II or III, or pacemaker were excluded from the study. Clinical parameters in patients with vs without atrial fibrillation were compared. To evaluate the association between interatrial block and postoperative atrial fibrillation univariable and multivariable regression analysis was performed.

Results: Out of 2374 patients, 1350 were amenable to analysis. Postoperative atrial fibrillation was documented in 505 (37.4%). In multivariable regression analysis prediction models with and without interatrial block were established. Step-wise regression analysis identified interatrial block (2.64[2.02; 3.46], p < 0.001), age (1.11[1.03; 1.20], p = 0.007), EuroScore II (1.05[1.03; 1.07], p < 0.001), pulmonary hypertension (1.91[1.24; 2.97], p = 0.006), history of cardiogenic shock (2.05[1.11; 3.87], p = 0.032), statins (1.66[1.21; 2.27], p = 0.002), COPD (2.11[1.25; 3.65], p = 0.009), and cardiopulmonary bypass time (1.78[1.04; 3.05], p = 0.047) as independent predictors for postoperative atrial fibrillation.

Conclusions: Preoperative interatrial block was associated with higher incidence of postoperative atrial fibrillation. Inclusion of ECG-derived preoperative conduction disturbances can enhance risk stratification of postoperative atrial fibrillation after heart surgery.