012\u2005Outcomes following confirmed myocardial injury in patients with atrial fibrillation: a post hoc subgroup analysis of the high-STEACS trial

Abstract

Troponin rise in patients with atrial fibrillation may be falsely attributed to oxygen demand-supply mismatch rather than acute atherothrombotic events requiring urgent percutaneous coronary intervention. The purpose of this study was to compare the differences in clinical presentation, management and outcomes between patients in atrial fibrillation and sinus rhythm presenting to the Emergency Department with a suspected acute coronary syndrome. This is the first report to describe the atrial fibrillation patient population recruited to the High-STEACS trial. Patients recruited to the High-Sensitivity Troponin in the Evaluation of patients with suspected Acute Coronary Syndromes (High-STEACS) trial from three sites across South East Scotland with confirmed myocardial injury diagnosed by high-sensitivity cardiac troponin I were included in a post hoc subgroup analysis (n=3597). Baseline patient characteristics, coronary revascularisation treatment and one-year mortality outcomes were compared between individuals in atrial fibrillation and sinus rhythm. 517 (14.4%) of patients presenting to Emergency Departments with confirmed myocardial injury were found to be in atrial fibrillation. One year all-cause mortality was higher in this population compared to patients presenting in sinus rhythm (24.8% vs 16.9%; p<0.001). Patients in atrial fibrillation were less likely to undergo invasive coronary angiography (21.5% vs. 59.8%; p<0.001) or urgent revascularisation with either percutaneous coronary intervention or coronary artery bypass grafting (13.2% vs. 45.2%; p<0.001). These patients were also more likely to receive an adjudicated diagnosis of myocardial injury or type 2 myocardial infarction (67.1% vs. 25.2%; p<0.001). However, there was no related increase in the incidence of unplanned coronary revascularisation in the year following index presentation (4.5% vs. 6.9%; p=0.05). Although patients in atrial fibrillation have poorer clinical outcomes, these results are likely to indicate an older population with higher multimorbidity rather than a missed opportunity for active treatment during initial presentation to the Emergency Department.