Post-cardiotomy pericardial effusion and postoperative atrial fibrillation risk.

Postoperative atrial fibrillation is a poor prognostic factor associated with increased mortality rates. Patients experiencing significant pericardial effusion develop postoperative atrial fibrillation; however, little is explored about the association between postoperative atrial fibrillation and post-cardiotomy pericardial effusion. This retrospective, single-center study included adult patients who underwent cardiovascular surgery via median sternotomy from January 2016 to December 2019. Patients who underwent routine postoperative computed tomography at 7 ± 3 days after surgery (n = 294) were included. Pericardial effusion was measured at the thickest point. Patients were classified into those with (n = 127) and without (n = 167) postoperative atrial fibrillation. The association of pericardial effusion with other factors was evaluated. A possible confounder-adjusted logistic regression analysis after multiple imputation was performed to obtain odds ratios for postoperative atrial fibrillation using previously published risk factors. Age, intraoperative bleeding volume, and pericardial effusion size were all significantly higher in the group with postoperative atrial fibrillation. Multivariate logistic regression after multiple imputation revealed that age, intraoperative bleeding volume, and postoperative pericardial effusion were significantly associated with postoperative atrial fibrillation. Our findings suggest that post-cardiotomy pericardial effusion is associated with postoperative atrial fibrillation. However, the causality remains unknown, making further studies mandatory.