Association between rivaroxaban and the prognosis of patients with acute myocardial infarction and new-onset atrial fibrillation

Abstract Background New-onset atrial fibrillation (AF) in the setting of acute myocardial infarction (AMI) is associated with higher risks of stroke and mortality. However, current guidelines lack specific antithrombotic recommendations for this population. Purpose This study aimed to explore the association between rivaroxaban and the prognosis of patients with AMI and new-onset AF. Methods This retrospective cohort study included patients with AMI and new-onset AF receiving dual antiplatelet therapy between August 2016 and June 2023 in China. New-onset AF, including transient and recurrent AF, was defined as the first diagnosis of AF in the setting of AMI. The primary outcome was stroke. The secondary outcomes included ischemic stroke, hemorrhagic stroke, all-cause mortality, cardiovascular mortality, bleeding, and major bleeding. Results A total of 2,477 patients were identified, including 141 rivaroxaban users and 2,336 non-users. Over a median follow-up of 922 days, rivaroxaban users had an approximate 5.7% lower risk of stroke compared to non-users, although this was not statistically significant (19.9% vs. 25.6%; P=0.152). Despite the suggestion of a protective trend, multivariable Cox regression showed that rivaroxaban use was not associated with a lower risk of stroke (hazard ratio, 0.77; 95% confidence interval, 0.52-1.13, P=0.187). In the propensity score matched cohort (1:3 ratio), no significant association was observed between rivaroxaban use and risks of stroke, ischemic stroke, hemorrhagic stroke, all-cause mortality, cardiovascular mortality, bleeding, or major bleeding in patients with transient or recurrent AF. Conclusions Among patients with AMI and new-onset AF receiving dual antiplatelet therapy, no significant association was observed between rivaroxaban use and the risks of stroke, ischemic stroke, hemorrhagic stroke, all-cause mortality, cardiovascular mortality, bleeding, or major bleeding.Rivaroxaban in AMI with new-onset AF.