New onset postoperative atrial fibrillation and early anticoagulation after cardiac surgery.

Objectives: New onset postoperative atrial fibrillation (POAF) after cardiac surgery is associated with increased risk for thromboembolic complications. Compliance with anticoagulation treatment is prerequisite for successful outcome after POAF. We hypothesized that a disciplined anticoagulation protocol initiated instantly after POAF secures a long-term outcome.

Design: A total of 519 consecutive patients undergoing cardiac surgery were retrospectively analyzed. Patients received anticoagulation using warfarin whenever POAF lasted longer than five min. Postoperative outcome including mortality, myocardial infarction and stroke were compared with patients on sinus rhythm (non-POAF).

Results: Mean age of the study cohort was 64.3 ± 9.0 years and median follow-up time was 76 months. There were 177 (34%) POAF and 342 (66%) non-POAF patients. At discharge, 144 (81%) POAF patients complied with warfarin, while 82 (24%) non-POAF patients received warfarin for non-rhythm causes (p < .001). Mortality was higher in POAF as compared with non-POAF patients (p = .03). After adjustment for comorbidities, major adverse clinical events (MACE)- including a combination of late cardiovascular mortality, myocardial infarction, stroke and late atrial fibrillation- was independently associated with POAF (OR 2.73, 95%CI 1.69-4.45, p < .0001).

Conclusions: POAF after cardiac surgery was associated with high risk of MACE. Early anticoagulation may be justified in POAF patients to secure a long-term outcome after cardiac surgery.