Anticoagulation in New Onset Postoperative Atrial Fibrillation After CABG

An increased risk of death among patients with new onset postoperative atrial fibrillation (AF) following coronary artery bypass graft (CABG) has been linked with anticoagulation medication. Ischemic stroke is not reduced in patients discharged on anticoagulation regardless of risk evaluation with CHA₂DS₂-VASc score. These are among the findings published in Heart Rhythm O².

Researchers aimed to evaluate the association between treating postoperative AF with anticoagulation and long-term outcomes. They conducted a retrospective analysis of 38,936 adult patients identified through the Society of Thoracic Surgeons Adult Cardiac Surgery Database and linked to the Medicare Database. Patients had postoperative AF following CABG, and 25% were discharged on oral anticoagulation therapy. The researchers used propensity score matching to show the association of discharge anticoagulation therapy with increased mortality (hazard ratio [HR] 1.16; 95% CI, 1.06-1.26). They found significantly greater bleeding (HR 1.60; 95% CI, 1.38-1.85) among patients discharged on anticoagulation therapy, but no difference in ischemic stroke between those on anticoagulation therapy and those not on anticoagulation therapy (HR 0.97; 95% CI, 0.82-1.15).

Patients with CHA₂DS₂-VASc scores of 5 or higher had a greater incidence of complications than patients with scores of 2 to 4, though neither subgroup seemed to benefit from anticoagulation therapy. Following discharge on anticoagulation therapy, myocardial infarction was lower in the first 30 days, but less so after 30 days.

Study limitations include the retrospective nature not completely accounting for confounding variables and true outcomes may not have been estimated accurately. There may also be prescribing bias in some clinicians.

“Anticoagulation is associated with increased mortality after new onset [postoperative] AF following CABG,” the researchers noted. They also found “no reduction in ischemic stroke among those discharged on anticoagulation regardless of CHA2DS2-VASc score.”

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

Reference

Riad FS, Grau-Sepulveda M, Jawitz OK, et al. Anticoagulation in new onset postoperative atrial fibrillation: an analysis from the Society of Thoracic Surgeons Adult Cardiac Surgery Database. Heart Rhythm O2. Published online June 15, 2022. doi:10.1016/j.hroo.2022.06.003