A comparison of outcome in patients with preoperative atrial fibrillation and patients in sinus rhythm

Background: Approximately 10% to 15% of patients undergoing cardiac operations suffer from atrial fibrillation (AF) at the time of surgery. The current risk stratification methods do not include preoperative arrhythmias. The aim of this study was to assess the effect of preoperative AF on the immediate postoperative outcome of patients undergoing cardiac surgery as well as in the midterm and long-term outcomes.

Methods: We reviewed patient data for our institution for a 10-year period; a total of 14,320 patients undergoing any cardiac operation were included; 12,395 (86.5%) had sinus rhythm preoperatively and 1,925 (13.5%) were in persistent AF. After propensity matching and adjusting for the preoperative and operative characteristics, 1,800 patients remained in each group and were compared.

Results: Before and after adjusting for the preoperative and operative characteristics, inotropic support, ventilation time, renal failure, stroke, and surgical wound infection rates were all significantly higher for the patients with AF (p < 0.001). Intensive care unit stay and hospital stay as well as in-hospital mortality were also significantly higher among the patients with AF compared with the sinus rhythm group (p < 0.001). At 30 days, 5-year and 10-year mortality rates in the AF group were significantly higher compared with those in sinus rhythm group (p < 0.001).

Conclusions: Atrial fibrillation preoperatively is associated with a higher incidence of postoperative complications. This arrhythmia is an important variable that appears to have been excluded from the current risk stratification systems. Our experience suggests that AF should be considered in the development/update of risk-stratifying methodologies to improve the predictive accuracy.