Oral Anticoagulants Touted as Having “Excellent Efficacy” in Postoperative Atrial Fibrillation

A recent prospective, observational study looked to investigate the use of direct oral anticoagulants (DOACs) for use in patients with postoperative atrial fibrillation (POAF).

POAF, the most common complication after cardiac surgery, has an incidence of 16% to 85%. Stroke is the most important clinical outcome of POAF and significantly affects the prognosis of the patient. The authors noted that at their medical facility, 24% of the 761 patients who underwent isolated coronary artery bypass grafting experienced POAF, and 1.4% of these patients also experienced a stroke. Although anticoagulation therapy consisting of heparin and warfarin was administered shortly after POAF, stroke still occurred in 1.4% of patients. This led the authors to administer DOAC immediately after the occurrence of POAF in patients after undergoing cardiac surgery.

The study looked at data from 135 total patients who were classified into 3 drug treatment groups: apixaban (n = 31), edoxaban (n = 87), and rivaroxaban (n = 17). Primary end points were either bleeding or thromboembolic events. Secondary end points were changes in hemoglobin prothrombin time, activated partial thromboplastin time, serum creatinine, estimated glomerular filtration rate, and pleural/pericardial effusion.

Despite no significant differences observed in age, sex, body weight, creatinine clearance, basic disease, risk factors, and presurgical anticoagulation therapy, the onset of POAF was similar across the 3 treatment groups. Although no hospital deaths occurred, the total number of events was significantly higher in the rivaroxaban group (P = .007).

In terms of primary end points, gastrointestinal (GI) bleeding was observed in 3% (n = 1), 1% (n = 1), and 12% (n = 2) of the apixaban, edoxaban, and rivaroxaban groups, respectively. Pleural bleeding was seen in 6% of patients in the rivaroxaban group (n = 1). Major bleeding and GI bleeding were more common in the rivaroxaban group (major bleeding: P = .011; GI bleeding: P = .047).

Analysis of the secondary end points found that in all 3 groups, there were no significant changes in hemoglobin from pretreatment to post DOAC treatment (P = .543), but hemoglobin did increase 1 month after administration of DOAC treatment (P < .0001) in each group. Prothrombin time was significantly more prolonged in apixaban than edoxaban at week 1 and month 1 (one week: P = .017; one month: P = .012). Similarly, activated partial thromboplastin time was more prolonged in the apixaban group than the rivaroxaban group (P = .011). In terms of pleural and pericardial infusion, there were no statistically significant differences across treatment groups (P = .840). Differences in serum creatinine and creatinine clearance were also not statistically significant. Notably, stroke was observed in 1 patient in the rivaroxaban group.

The authors found that the safety of DOACs was favorable, noting a low incidence of major bleeding. As there was only 1 case of stroke observed in the study, the authors wrote that “the efficacy of DOAC is excellent.” However, the authors also recommended that a future randomized, multicenter clinical trial should be conducted in order to further investigate the differences among DOACs.

Reference

Sezai A, Taoka M, Osaka S, et al. A comparative prospective observational study on the use of direct oral anticoagulants after cardiac surgery for the management of atrial fibrillation. Ann Thorac Cardiovasc Surg. Published online November 18, 2020. doi:10.5761/atcs.oa.20-00213