Temporal Trends of Antithrombotic Therapy in Patients With Acute Myocardial Infarction and Atrial Fibrillation: Insight From the KAMIR-NIH Registry

Background: Triple therapy is the combination of dual antiplatelet therapy plus oral anticoagulant after stent implantation. Current guidelines recommend triple therapy for acute coronary syndrome with atrial fibrillation (AF). This study aimed to identify temporal trends of antithrombotic therapy in patients with acute myocardial infarction (AMI) and AF. Methods: Among 13,104 consecutive patients from the Korea Acute Myocardial Infarction Registry-National Institute of Health (KAMIR-NIH) registry, we identified 453 patients with AF after stent implantation for AMI; these patients were then divided into those who did and did not use oral anticoagulant (OAC) [OAC group ( n = 71) vs. non-OAC group ( n = 382), respectively]. Results: The results showed that the prevalence of AF in AMI patients was 5.4% (712/13,104). Among 453 patients, only 15.7% (71/453) were treated with OAC while dual or single antiplatelet therapy was provided for 84.7% (382/453) of patients. In patients with high stroke risk (CHA 2 DS 2 -VASc score ≥ 2), OACs were used only in 17% (69/406). Multivariate analysis revealed that female sex [odds ratio (OR) 2.11; 95% CI: 1.17–3.79], diabetes mellitus (DM) (OR 2.37; 95% CI: 1.35–4.17), prior cerebrovascular accident (CVA) (OR 4.19; 95% CI: 2–8.75), and congestive heart failure (CHF) (OR 1.89; 95% CI: 1.09–3.3) as the significant determinants of OAC use. Conclusion: The study concluded that OAC was underused. Approximately, 15%, of AMI patients with AF undergoing PCI with stent and female gender, DM, prior CVA history, and a history of CHF or the presence of moderate to severe left ventricle systolic impairment were significant determinants of OAC use.