Postoperative atrial fibrillation following coronary artery bypass graft: clinical factors associated with in-hospital death.

Objective: To identify factors associated with a higher likelihood of in-hospital death in patients submitted to coronary artery bypass graft surgery (CABG) who developed atrial fibrillation (AF) postoperatively.

Methods: The authors analyzed data from 397 consecutive patients submitted to CABG that developed AF postoperatively between 2000 and 2003. The patients were divided into 2 groups: group 1 (G1) comprised patients who survived (n=369); and group 2 (G2) comprised patients who died during hospital stay (n=28). Statistical analysis was performed using Student's t test and chi-square test, and p values < 0.05 were considered significant.

Results: A comparative analysis between G1 and G2 showed that there was no difference between the groups as regards age (67.3 +/- 8.4 versus 69.3 +/- 9.6; p = 0.4), male gender (75.9% versus 64.3%; p = 0.1), systemic arterial hypertension (75.3% versus 85.7%; p = 0.2) and congestive heart failure (17% versus 17%; p = 1). Group 2 presented higher rates for previous acute myocardial infarction (14.6% versus 28.6%; p = 0.05), left ventricular ejection fraction < 40% (12.2% versus 32.1%; p = 0.003), previous cerebrovascular accident (0.8% versus 17.9%; p = 0.03), previous percutaneous coronary intervention (19.5% versus 39.3%; p = 0.01) and previous CABG (19.3% versus 35.7%; p = 0.03).

Conclusion: Clinical history of acute myocardial infarction, CABG, percutaneous coronary intervention, cerebrovascular accident and severe ventricular dysfunction were significantly more frequent in the group that died during hospital stay, which suggests a possible association of these factors with a higher likelihood of death following CABG.