Sex-related differences in benefits of anticoagulation therapy in elderly patients with atrial fibrillation: a subanalysis of the EMERG-AF study

Objectives. To analyze the long-term benefits and safety of oral anticoagulation therapy prescribed in emergency departments for elderly patients with atrial fibrillation, and to detect any sex-related differences present.Methods. Post-hoc analysis of data compiled by the EMERG-AF group (Spanish acronym for Emergency Department Stroke Prophylaxis and Guidelines Implementation in Atrial Fibrillation). Consecutive patients aged 75 years or older with atrial fibrillation who were treated in 62 EDs were included. We recorded clinical data and anticoagulants prescribed. Patients were followed for 1 year. The main outcome variable was a composite of death, thromboembolism, or major bleeding within 1 year.Results. Data for 690 patients were registered; 386 (55.9%) were women. At discharge, 575 patients (83.3%) were on anticoagulants; therapy was started in the ED for 96 of them. A total of 158 patients (22.9%) had experienced at least 1 component of the main outcome within 1 year: 118 (17.1%) died, 22 (2.7%) had thromboembolic complications, and 34 (4.9%) had major bleeding. After adjustment for main clinical characteristics, hazard ratios (HRs) showed that anticoagulation therapy was associated with a reduction in the composite outcome (HR, 0.372; 95% CI, 0.236-0.587; P <.001) but not specifically with major bleeding overall. When data for women were analyzed separately, anticoagulant therapy was again associated with a reduction in the composite outcome (HR, 0.372; 95% CI, 0.236-0.587; P <.001) and also with death (HR, 0.281; 95% CI, 0.168-0.469; P <.001), even in patients with anticoagulant prescriptions initiated on discharge from the ED. These associations did not reach statistical significance in men.Conclusions. ED anticoagulant prescription for elderly patients with atrial fibrillation is safe and contributes to a reduction in mortality. Women in this age group benefited more than men from starting anticoagulation during the acute phase in the ED.