Amiodarone plus apixaban/rivaroxaban ups bleeding-related hospitalizations in older AF patients

Use of amiodarone in older patients with atrial fibrillation (AF) who are being treated with apixaban or rivaroxaban results in a higher risk of bleeding-related hospitalizations compared with the use of flecainide or sotalol, reports a study.

“Amiodarone, the most effective antiarrhythmic drug in AF, inhibits apixaban and rivaroxaban elimination, thus possibly increasing anticoagulant-related risk for bleeding,” the researchers said.

This retrospective study included US Medicare beneficiaries aged ≥65 years with AF who initiated anticoagulant use between 1 January 2012 and 30 November 2018 and subsequently treated with antiarrhythmic drugs.

The primary outcome was time to event for bleeding-related hospitalizations, while ischaemic stroke, systemic embolism, and death with or without recent (past 30 days) evidence of bleeding were secondary. Adjustments were made with propensity score overlap weighting.

A total of 91,590 patients (mean age 76.3 years, 52.5 percent female) initiating use of anticoagulants and antiarrhythmic agents were included in the analysis. Of these, 54,977 received amiodarone and 36,613 used flecainide or sotalol.

Amiodarone use correlated with an increased risk for bleeding-related hospitalizations (rate difference [RD], 17.5 events per 1,000 person-years, 95 percent confidence interval [CI], 12.0‒23.0; hazard ratio [HR], 1.44, 95 percent CI, 1.27‒1.63). On the other hand, no increase was observed in the incidence of ischaemic stroke or systemic embolism (RD, ‒2.1 events per 1,000 person-years, 95 percent CI, ‒4.7 to 0.4; HR, 0.80, 95 percent CI, 0.62‒1.03).

The mortality risk with recent evidence of bleeding (RD, 9.1 events per 1,000 person-years, 95 percent CI, 5.8‒12.3; HR, 1.66, 95 percent CI, 1.35‒2.03) was higher compared with that for other deaths (RD, 5.6 events per 1,000 person-years; HR, 1.15, 95 percent CI, 1.00‒1.31; p=0.003).

Additionally, the increased incidence of bleeding-related hospitalizations with rivaroxaban (RD, 28.0 events per 1,000 person-years) was higher than that with apixaban (RD, 9.1 events per 1,000 person-years, 95 percent CI, 2.8‒15.3; p=0.001).