Outcomes Associated With Oral Anticoagulants Plus Antiplatelets in Patients With Newly Diagnosed Atrial Fibrillation

Question What outcomes are associated with combination therapy using oral anticoagulants (OAC) plus antiplatelet drugs in patients with newly diagnosed atrial fibrillation? Findings This cohort study of 24 & x202f;436 patients with de novo atrial fibrillation found that, after adjusting for baseline characteristics and comedications, patients treated with OAC plus antiplatelet drugs had significantly higher incidence rates of stroke and any bleeding event than those receiving OAC alone. Use of OAC plus antiplatelet drugs was not associated with reduced risk of experiencing acute coronary syndromes. Meaning These findings suggest that patients with atrial fibrillation treated with OAC plus antiplatelet drugs may have significantly higher risk of stroke and bleeding compared with those receiving OAC alone. This cohort study compares outcomes of treatment with oral anticoagulants plus antiplatelet drugs vs oral anticoagulants alone in patients with newly diagnosed atrial fibrillation. Importance Patients with nonvalvular atrial fibrillation at risk of stroke should receive oral anticoagulants (OAC). However, approximately 1 in 8 patients in the Global Anticoagulant Registry in the Field (GARFIELD-AF) registry are treated with antiplatelet (AP) drugs in addition to OAC, with or without documented vascular disease or other indications for AP therapy. Objective To investigate baseline characteristics and outcomes of patients who were prescribed OAC plus AP therapy vs OAC alone. Design, Setting, and Participants Prospective cohort study of the GARFIELD-AF registry, an international, multicenter, observational study of adults aged 18 years and older with recently diagnosed nonvalvular atrial fibrillation and at least 1 risk factor for stroke enrolled between March 2010 and August 2016. Data were extracted for analysis in October 2017 and analyzed from April 2018 to June 2019. Exposure Participants received either OAC plus AP or OAC alone. Main Outcomes and Measures Clinical outcomes were measured over 3 and 12 months. Outcomes were adjusted for 40 covariates, including baseline conditions and medications. Results A total of 24 & x202f;436 patients (13 & x202f;438 [55.0%] male; median [interquartile range] age, 71 [64-78] years) were analyzed. Among eligible patients, those receiving OAC plus AP therapy had a greater prevalence of cardiovascular indications for AP, including acute coronary syndromes (22.0% vs 4.3%), coronary artery disease (39.1% vs 9.8%), and carotid occlusive disease (4.8% vs 2.0%). Over 1 year, patients treated with OAC plus AP had significantly higher incidence rates of stroke (adjusted hazard ratio [aHR], 1.49; 95% CI, 1.01-2.20) and any bleeding event (aHR, 1.41; 95% CI, 1.17-1.70) than those treated with OAC alone. These patients did not show evidence of reduced all-cause mortality (aHR, 1.22; 95% CI, 0.98-1.51). Risk of acute coronary syndrome was not reduced in patients taking OAC plus AP compared with OAC alone (aHR, 1.16; 95% CI, 0.70-1.94). Patients treated with OAC plus AP also had higher rates of all clinical outcomes than those treated with OAC alone over the short term (3 months). Conclusions and Relevance This study challenges the practice of coprescribing OAC plus AP unless there is a clear indication for adding AP to OAC therapy in newly diagnosed atrial fibrillation.