Background:
We hypothesized that patients with new onset atrial fibrillation (AFib) following cardiac or non-cardiac surgery have similar echocardiographic features, regardless of the type of surgery.
Methods:
Study cohort included 4562 consecutive patients without history of atrial fibrillation undergoing general, thoracic or cardiovascular surgeries at a single tertiary academic medical center. Retrospective chart and echocardiogram review was performed. Chi-square, logistic regression, and analysis of variance were performed. Long-term all cause mortality was determined through Social Security Death Index. The study was approved by the institutional IRB.
Results:
Post-operative AFib was noted in 24% (275/1141) after cardiac surgery, 1.2 % (10/804) after thoracic non-cardiac surgery, and 0.7% (18/2617) after general non-cardiac non-thoracic surgery (p<0.0001).
On available echocardiograms, 18% (48/264) had LV dilatation and 38% (98/261) had moderate or severe LV dysfunction. The left atrium was dilated in 53% (139/260). Moderate or severe tricuspid regurgitation was noted in 11% (15/128), mitral regurgitation in 28% (45/16), mitral stenosis in 13% (11/82), aortic insufficiency in 27% (37/135), and aortic stenosis in 63% (19/135).
When adjusted for the presence of coronary artery disease, valvular disease, age, and gender, only aortic valve stenosis remained an important independent predictor of post-operative atrial fibrillation in non-cardiac surgery patients, HR=13.9 (95%CI 1.5-132.3, p<0.022).
Conclusion:
Despite significantly increased prevalence of new onset AFib after cardiac surgery, pre-existing cardiovascular conditions, specifically aortic valve stenosis, confer an increased risk of post-operative atrial fibrillation rather than the procedure itself. Improved resource utilization can be expected if post-operative ECG monitoring is limited to the high risk patients, identifiable during peri-operative screening. Prospective studies of this important subject are needed.
Commentary: Post operative atrial fibrillation: Out of sight out of mind
