New-onset postoperative atrial fibrillation and long-term survival after aortic valve replacement surgery

Abstract

Background: Atrial fibrillation (AF) is recognized as a common complication of open cardiac surgery, occurring in up to 65% of patients. The advancing age and increasing risk profile of patients receiving aortic valve replacement (AVR) surgery is expected to raise incidence of new-onset postoperative AF resulting in potentially higher risk of adverse outcomes. In the early postoperative course, new-onset post-AVR AF is considered relatively easy to treat and is believed to have little impact on patients' long-term outcome. However, the effect of new-onset post-AVR AF on long-term survival is unclear.

Methods: Survival was assessed in 1,039 consecutive patients without preoperative AF who underwent AVR with or without simultaneous coronary artery bypass graft at Baylor University Medical Center, Dallas, Texas between January 1, 1997 and December 31, 2006.

Results: Ten-year unadjusted survival was 50.8% for patients with new-onset postoperative AF and 59.4% for patients without. A propensity-adjusted model controlling for risk factors identified by the Society of Thoracic Surgeons and other clinical-nonclinical details was used to investigate the association between new-onset AF post-AVR and survival. After adjustment, new-onset AF post-AVR was significantly associated with increased risk of death (hazard ratio: 1.48; 95% confidence interval 1.12 to 1.96).

Conclusions: This study provides evidence that new-onset post-AVR AF is significantly associated with increased long-term risk of mortality independent of the preoperative severity of disease. After controlling for a comprehensive array of risk factors associated with post-AVR adverse outcomes, risk of long-term mortality in patients who developed new-onset post-AVR AF was 48% higher than in patients without it.