Use of Anticoagulation Therapy in Patients With Perioperative Atrial Fibrillation After Cardiac Surgery: A Systematic Review and Meta-analysis

Background: Perioperative atrial fibrillation (POAF) after cardiac surgery is associated with an increased risk of stroke. However, the efficacy and safety of using anticoagulation therapy in this population are unknown. Methods: We performed a systematic review and meta-analysis of studies comparing use of anticoagulation therapy vs no anticoagulation therapy in patients with POAF after cardiac surgery. Outcomes included arterial thromboembolism (ie, stroke ± systemic embolism) and bleeding. Data were pooled using fixed-effects models. We reported summary risk ratios (RRs) for studies with multivariable adjustment and estimated absolute risk differences with 95% confidence intervals (CIs). Results: Nine observational studies met eligibility criteria. No randomized trials were identified. Of the 254,200 POAF patients included, 27.3% received anticoagulation. Six studies reported outcomes after long-term follow-up (median 5.0 years; range 4.2-10.0). The risk of arterial thromboembolism was lower in patients receiving anticoagulation therapy (RR 0.83; 95% CI, 0.69-0.99; I² = 57%; P = 0.04; 6 studies). The estimated short-term and long-term absolute risk reductions in arterial thromboembolism with use of anticoagulation therapy were 0.8% (95% CI, 0.4-1.4) and 2 events per 1000 person-years (95% CI, 0-4), respectively. The risk of bleeding was higher in patients receiving anticoagulation therapy (RR 3.22; 95% CI, 2.82-3.68; I² = 98%; P < 0.001; 2 studies). The estimated short-term and long-term absolute risk increases in bleeding with use of anticoagulation therapy were 0.5% (95% CI, 0.4-0.6) and 42 events per 1000 person-years (95% CI, 35-51), respectively. Conclusions: Use of anticoagulation therapy is associated with a small reduction in the risk of arterial thromboembolism, but also an increased risk of bleeding. Randomized controlled trials are needed to address this issue.