Oral anticoagulation and outcomes in patients with acute myocardial infarction: Insights from the Hungarian Myocardial Infarction Registry

Introduction Anticoagulation reduces the risk of stroke and embolization and is recommended in most patients with atrial fibrillation. Patients after coronary intervention and acute coronary syndromes require antiplatelet treatment. Although oral anticoagulation (OAC) therapy may interfere with the outcome of patients after coronary intervention, its exact impact remains unclear. Importantly, risk-benefit relations may be considerably different after myocardial infarction. Material and Methods Data of patients registered from the Hungarian Myocardial Infarction Registry, a mandatory nationwide program for hospitals treating patients with myocardial infarction, were processed. Patients registered between 01.2014. and 12.2017 were included. All-cause mortality, the composite of cardiac events (MACE), and transfusion were compared between patients receiving OAC treatment and a propensity score (PS) matched control group. Subgroup analyses of different anticoagulation and antiplatelet strategies were performed with propensity weighted Cox proportional hazards' models to estimate risk during the first year after the index event. Results From 30 681 patients 1875 cases received OAC treatment and had apparently worse prognosis. After PS-matching, however, we found no difference regarding mortality (hazard ratio [HR]: 0.91 95% CI 0.77-1.09, P = .303), MACE (HR: 0.92 95% CI 0.78-1.09, P = .335) or transfusion (HR: 1.21, 95% CI 0.97-1.49, P = .086). In PS-adjusted analyses for the OAC group, patients who received aspirin were associated with lower mortality (HR: 0.77, 95% CI: 0.60-0.997, P = .048) and MACE (HR:0.73, 95% CI 0.58-0.92, P = .008) compared to those without aspirin. Conclusions In patients with acute myocardial infarction, the prognosis of OAC-treated patients was comparable to the PS matched control; however, the omission of aspirin therapy was associated with unfavorable outcomes.