Oral Anticoagulants for the Treatment of Postoperative Atrial Fibrillation?

The authors of a letter to the editor published in the Canadian Journal of Cardiology, recommend caution when altering oral anticoagulants (OAC) prescriptions for patients with postoperative atrial fibrillation (POAF), following the publication of conflicting evidence.

This letter was published in response to a study in which treatment with POAFs after noncardiac surgery was examined. In this study, OAC treatment was found to be associated with increased risk for major bleeding (adjusted hazard ratio [aHR], 1.2; 95% CI, 1.1-1.32), but not with a reduction of the risk for thromboembolic events (aHR, 0.89; 95% CI, 0.73-1.07). In addition, overall stroke rate was 1.5 per 100 patient-years. These results highlight the potential negative aspects of OAC use in patients with POAF.

It remains unclear whether new-onset AF after noncardiac surgery truly is AF, or whether its occurrence is benign and reversible. The authors of the letter highlight limitations of this study, which include its observational design, the use of administrative data, and a heterogeneous definition of major bleeding events.

In addition, these results are in conflict with the current European Society of Cardiology guidelines, in which it is stated that all patients at risk for thromboembolic events, including those with POAF after noncardiac surgery, are candidates for long-term OAC treatment.

The authors of the letter also note that alterations to current recommendations and clinical practice should only be implemented following results from adequately powered randomized clinical trials.

The Anticoagulation for Stroke Prevention In Patients With Recent Episodes of Perioperative Atrial Fibrillation After Noncardiac Surgery (ASPIRE-AF; ClinicalTrials.gov Identifier: NCT03968393) study is one such ongoing randomized trial. The Atrial Fibrillation Occurring Transiently with Stress (AFOTS) study is an ongoing follow-up cohort study which continuously monitorspatients with POAF for AF recurrence.

The authors note that the results of these forthcoming studies will likely help the community determine the best strategy for managing risk for thromboembolic and bleeding events in patients with POAF after noncardiac surgery, and that clinical practices should remain unchanged until these studies have been completed.

This opinion letter was biased by the fact that 2 of the authors are the principle investigators of the ASPIRE-AF and AFOTS studies.

Reference

McIntyre W F, Wang M K, Conen D. Balancing the risks and benefits of oral anticoagulant use in patients with post-operative atrial fibrillation. Can J Cardiol. 2020;S0828-282X(20)31066-7. doi:10.1016/j.cjca.2020.10.011