Atrial fibrillation in patients hospitalized with acute myocardial infarction: analysis of the china acute myocardial infarction (CAMI) registry

Background: The incidence, clinical outcomes and antithrombotic treatment spectrum of atrial fibrillation (AF) in patients hospitalized with acute myocardial infarction (AMI) have not been well studied in Chinese population. Methods: Twenty-six thousand five hundred ninety-two consecutive patients diagnosed with AMI were enrolled in CAMI registry from January 2013 to September 2014. After excluding 343 patients with uncertain AF status and 1,591 patients transferred out during hospitalization, 24,658 patients were finally included in this study and involved in analysis. Results: In the CAMI registry, 740 (3.0%) patients were recorded with AF prevalence during hospitalization. Higher-risk baseline clinical profile was observed in patients with AF. These patients were less likely to receive reperfusion/revascularization than those without AF. The in-hospital mortality (including death and treatment withdrawal) was significantly higher in patients with AF than that of without AF (25.2% vs. 7.2%, respectively; p < 0.01). The case of composite of adverse events was similar, which included death, treatment withdrawal, re-infarction, heart failure or stroke (42.1% vs. 16.0%, p < 0.01). In multivariate logistic regression analysis, AF was an independent predictor for in-hospital mortality (odds ratio, 1.88; 95% confidence interval: 1.27-2.78) and the composite of adverse events (odds ratio, 2.11; 95% CI: 1.63-2.72). Only 5.1% of patients with AF were treated with warfarin, and 1.7% were treated with both warfarin and dual antiplatelet therapy. Conclusions: The analysis was based on the CAMI registry in China. The patients hospitalized for AMI who developed AF were at significantly higher risk for in-hospital mortality and other adverse events. However, the anticoagulants including warfarin have been largely underused post hospital discharge.