Association between Postoperative Atrial Fibrillation Recurrences and Interatrial Block by the Time of Open-Heart Surgery

Background: Postoperative atrial fibrillation (PoAF) occurs in more than one third of patients after heart surgery. It may lead to complications such as stroke, heart failure and death. Interatrial block (IAB) has been related to increased risk of new onset atrial fibrillation in general population. However, little is known about the P-wave characteristics in relation to PoAF recurrences after cardiac surgery.

Method: A total of 1,258 patients without history of atrial fibrillation were included in a single-center cohort study. Patients underwent aortic valve replacement (AVR; n = 420), coronary arterial bypass grafting (CABG; n = 447), AVR with CABG (n = 331), mitral valve replacement (MVR) with CABG (n = 21), and mitral valve reconstruction with CABG (n = 39). Twelve-channel ECG recordings were read by three independent readers. Logistic regression analysis was used to identify factors, responsible for PoAF recurrence during the hospital stay. IAB was defined as P-wave ≥120 milliseconds with or without biphasic P wave morphology in the ECG leads II, III, and aVF.

Results: PoAF was detected in 449 (35.7%) patients, recurrent PoAF in 219 (17.4%) patients. Postoperative IAB (p < 0.001) was associated with increased PoAF recurrence in the univariate analysis, while it did not show significant association multivariately (p = 0.051). Recurrent PoAF was independently related to advanced age (p < 0.001), absent statin therapy (p < 0.001), MVR and CABG (p = 0.019), preexisting IAB (p = 0.008), LV-EF <40% (0.111), EuroSCORE II (p = 0.107), rethoracotomy (p = 0.012), increased creatinine levels (p < 0.001), and prolonged mechanical ventilation (p < 0.001), yielding the area under the receiver operating characteristic (AUC) of 0.778.

Conclusion: Approximately one-half of the patients’ experiences PoAF recurrently, preoperative IAB was independently related. Postoperative IAB was associated with PoAF recurrences univariately, while it exhibited borderline association in the multivariate analysis. As secondary endpoints, advanced age, absence of statin therapy, MVR and CABG, LV-EF <40%, EuroSCORE II, rethoracotomy, increased creatinine levels, and prolonged mechanical ventilation turned out to be strong predictors of PoAF in the multivariate analysis.

Publication History

Article published online:
28 January 2023