Atrial fibrillation after cardiac surgery: incidence, risk factors, and economic burden.

Objective: To evaluate the incidence of postoperative atrial fibrillation (POAF), the predisposing factors, the results of treatment before discharge, and the impact on duration and costs of hospitalization.

Design: A prospective observational study.

Methods: Patients who underwent cardiac surgery from January 1, 2007 to December 31, 2007.

Interventions: Electrocardiography was continuously monitored after surgery. Patients with symptomatic new-onset atrial fibrillation or lasting >15 minutes were treated with amiodarone and with DC shock in prolonged cases.

Results: POAF occurred in 29.7%, with the higher incidence between the 1st and 4th postoperative day. Age (p < 0.001), atrial size >40 mm (p < 0.001), previous episodes of AF (p < 0.001), female sex (p = 0.010), and combined valve and bypass surgery (p = 0.012) were multivariate predictors of POAF at logistic regression. Sinus rhythm was restored by early treatment in 205 of 215 patients. This was associated with a low incidence of cerebrovascular events (<0.5%) and with a limited increase of average length of hospitalization (24 hours) in patients with POAF.

Conclusions: The overall incidence of POAF in the authors' center is close to 30%; 95.3% of patients were discharged in sinus rhythm. The increase in length and costs of hospitalization (on average, 1.0 day with a burden of about €1,800/patient) were significantly lower than in previous investigations.