Clinical Implications of Preoperative Nonvalvular Atrial Fibrillation with Respect to Postoperative Cardiovascular Outcomes in Patients Undergoing Non-Cardiac Surgery

Background and Objectives: Atrial fibrillation (AF) is associated with a higher long-term risk of major cardiovascular events. However, its clinical implications with respect to peri-operative cardiovascular outcomes in patients undergoing non-cardiac surgery is unclear. We tried to examine the association between pre-operative AF and peri-operative cardiovascular outcomes. Methods: We retrospectively analyzed data from 26,501 consecutive patients who underwent comprehensive preoperative cardiac evaluations for risk stratification prior to receiving non-cardiac surgery at our center. Preoperative AF was diagnosed in 1,098 patients (4.1%), and their cardiovascular outcomes were compared with those of patients without AF. The primary outcome was the rate of major adverse cardiac and cerebrovascular events (MACCE) during immediate post-surgery period (<30 days). Results: Patients with AF were older and had higher proportion of male sex, higher rate of extra-cardiac comorbidities, higher CHA(2)DS(2)-VASc score, and higher revised cardiac risk index (RCRI) compared with those without AF. The rate of MACCE was significantly higher in AF patients compared to non-AF patients (4.6% vs. 1.2%, p<0.001). Preoperative AF was associated with higher risk of MACCE, even after multivariable adjustment (odds ratio, 2.97; 95% confidence interval, 2.13-4.07, p<0.001). The relative contribution of AF to MACCE was larger in patients with lower RCRI (p for interaction=0.010). The discriminating performance of RCRI was significantly enhanced by addition of AF. Conclusions: In patients undergoing non-cardiac surgery, preoperative AF was associated with a higher risk of peri-operative cardiovascular outcomes.