Incidence, Predictors, and Impact of Postoperative Atrial Fibrillation after Coronary Artery Bypass Grafting in Military Veterans

Abstract

Little is known about the frequency and clinical implications of postoperative atrial fibrillation in military veterans who undergo coronary artery bypass grafting (CABG). We examined long-term survival data, clinical outcomes, and associated risk factors in this population. We retrospectively reviewed baseline, intraoperative, and postoperative data from 1,248 consecutive patients with similar baseline risk profiles who underwent primary isolated CABG at a Veterans Affairs hospital from October 2006 through March 2013. Multivariable logistic regression identified predictors of postoperative atrial fibrillation. Kaplan-Meier analysis was used to evaluate long-term survival (the primary outcome measure), morbidity, and length of hospital stay. Postoperative atrial fibrillation occurred in 215 patients (17.2%). Independent predictors of this sequela were age ≥65 years (odds ratios [95% confidence intervals], 1.7 [1.3-2.4] for patients of age 65-75 yr and 2.6 [1.4-4.8] for patients >75 yr) and body mass index ≥30 kg/m² (2.0 [1.2-3.2]). Length of stay was longer for patients with postoperative atrial fibrillation than for those without (12.7 ± 6.6 vs 10.3 ± 8.9 d; P ≤0.0001), and the respective 30-day mortality rate was higher (1.9% vs 0.4%; P=0.014). Seven-year survival rates did not differ significantly. Older and obese patients are particularly at risk of postoperative atrial fibrillation after CABG. Patients who develop the sequela have longer hospital stays than, but similar long-term survival rates to, patients who do not.

Keywords: Atrial fibrillation/epidemiology/etiology/mortality; coronary artery bypass/adverse effects; hospitals, veterans/statistics & numerical data; length of stay; postoperative complications; predictive value of tests; proportional hazards models; retrospective studies; risk assessment; treatment outcome.

Fig. 1

Graph shows Kaplan-Meier analysis of survival outcomes and number at risk in the 1,248 patients who had and did not have postoperative atrial fibrillation (Postop AF).