Poor adherence to guideline recommendations among patients with atrial fibrillation and acute myocardial infarction

Abstract

Background The prevalence of atrial fibrillation in patients with acute myocardial infarction is largely unknown. The aims of the present study were to assess the prevalence of atrial fibrillation in a nationwide cohort of patients with acute myocardial infarction, to assess the prescription of anticoagulation therapy, and to study the long-term outcomes. Design A nationwide registry-based cohort study. Methods All patients registered in the Norwegian Myocardial Infarction Registry between 2013 and 2016 were included and followed up through 2017. Stroke rates during follow-up were obtained through linkage with the Norwegian Patient Registry. Results In total, 47,204 patients were registered in the Norwegian Myocardial Infarction Registry. Atrial fibrillation on admission was recorded in 5393 (11%) patients, and 2190 (5%) additional patients developed atrial fibrillation during their hospital stay. Only 45% of patients with atrial fibrillation on admission and CHA2DS2-VASc score\u2009≥\u20092 were treated with anticoagulation therapy prior to myocardial infarction, and 56% of patients with atrial fibrillation and CHA2DS2-VASc score\u2009≥\u20092 were prescribed anticoagulation therapy at discharge. Patients with myocardial infarction and atrial fibrillation had an increased risk of stroke or death during 822 (426, 1278) days of follow-up compared with patients without atrial fibrillation (multivariate adjusted hazard ratio 1.4, 95% confidence interval 1.3–1.4). Conclusions Almost half of patients with atrial fibrillation and myocardial infarction were not prescribed the guideline recommended treatment with anticoagulation therapy at discharge, and their long-term risk of stroke and death was increased compared with patients without atrial fibrillation. Increased efforts to improve the treatment of patients with myocardial infarction and atrial fibrillation are needed.