Red cell transfusion is associated with an increased risk for postoperative atrial fibrillation

Atrial fibrillation (AF) is a common complication after cardiac surgery and is associated with increased resource utilization. Recent evidence supports a role of inflammation in the development of AF. It is also known that red blood cell transfusion modulates inflammation by increasing plasma levels of inflammatory markers. Therefore, we tested the hypothesis that red blood cell transfusion increases the risk of postoperative AF for patients undergoing cardiac surgery.

Between February 2002 and January 2005, 5,841 patients underwent isolated coronary artery bypass grafting with or without valve replacement. Patient and procedural variables associated with development of new-onset AF were identified by logistic regression. Propensity score matching was used to confirm results.

In addition to older age, prior history of AF, higher preoperative hematocrit, beta-blocker withdrawal, longer aortic clamp time, valve surgery, and intensive care unit inotropic usage, intensive care unit red blood cell transfusion increased risk for AF (odds ratio per unit transfused, 1.18; 95% confidence limits, 1.14, 1.23; p < 0.0001). For the 1,360 propensity-matched pairs, intensive care unit red blood cell transfusion was associated with a significant increase in new-onset AF (620 [46%] versus 522 [38%]; p < 0.001).

Intensive care unit red blood cell transfusion is associated with increased occurrence of postoperative AF after cardiac surgery. This factor should be considered in identifying patients who might benefit from prophylaxis to prevent this common postoperative complication.