The prohemorrhage interaction of amiodarone with direct oral anticoagulants produces a greater risk for bleeding-related hospitalizations with apixaban or rivaroxaban than with flecainide or sotalol, conclude investigators who conducted a retrospective cohort study of older adults.
Among U.S. Medicare beneficiaries aged 65 years or older, these patterns were apparent using a primary outcome measure of time to event for bleeding-related hospitalizations: “There were 91,590 patients (mean age, 76.3 years; 52.5% female) initiating use of study anticoagulants and antiarrhythmic drugs, 54,977 with amiodarone and 36,613 with flecainide or sotalol. Risk for bleeding-related hospitalizations increased with amiodarone use (rate difference [RD], 17.5 events [95% CI, 12.0 to 23.0 events] per 1,000 person-years; hazard ratio [HR], 1.44 [CI, 1.27 to 1.63]). Incidence of ischemic stroke or systemic embolism did not increase (RD, −2.1 events [CI, −4.7 to 0.4 events] per 1,000 person-years; HR, 0.80 [CI, 0.62 to 1.03]). The risk for death with recent evidence of bleeding (RD, 9.1 events [CI, 5.8 to 12.3 events] per 1,000 person-years; HR, 1.66 [CI, 1.35 to 2.03]) was greater than that for other deaths (RD, 5.6 events [CI, 0.5 to 10.6 events] per 1,000 person-years; HR, 1.15 [CI, 1.00 to 1.31]) (HR comparison: P = 0.003). The increased incidence of bleeding-related hospitalizations for rivaroxaban (RD, 28.0 events [CI, 18.4 to 37.6 events] per 1,000 person-years) was greater than that for apixaban (RD, 9.1 events [CI, 2.8 to 15.3 events] per 1,000 person-years) (P = 0.001).”