Role of cardiac troponins in the emergency department in patients with atrial fibrillation

Abstract Atrial fibrillation (AF) is the most frequent arrhythmia among those encountered in the emergency department. It’s well known that elevated values ​​of cardiac troponin in "stable” conditions is generally indicative of myocardial cytonecrosis and is associated with a worse prognosis in various clinical conditions. The role of cardiac biomarkers in the context of an AF episode has not yet been fully understood and is a source of debate in the cardiology community. Recent studies suggest the association of elevated troponin values in the context of an AF episode with an increased incidence of major cardiovascular events. Consequently, its measurement could be extensively taken into consideration also in the Emergency Department and implemented for risk stratification. There is currently insufficient evidence to support the dosing of cardiac troponins in all AF patients for risk stratification. The aim of this study is to investigate the significance of elevated troponin values ​​during AF and whether these are related to an increased cardiovascular risk. Methods and Results This is a retrospective and observational study and focuses on a population of patients who arrived in the Emergency Department of San Raffaele Hospital in Milan between the 1st of January 2018 and 22nd May 2021 with atrial fibrillation. Data were collected for 625 patients of whom 232 were enrolled for statistical analysis. The population was stratified based on cardiovascular risk factors and prior AF ablation. At 12–month follow–up we found that elevated troponin values ​​during atrial fibrillation in the Emergency Department do not correlate with an increase of deaths from any cause, major cardiovascular events or hospitalizations for heart failure. The presence of elevated cardiac troponin was not associated with an increased rate of CAD at coronary CT nor coronaru angiography. A weak association was seen between non–elevated cTnT–hs and higher rate of AF ablation. Conclusions Our data reject the hypothesis according to which elevated levels of highly sensitive cardiac troponin measured during an atrial fibrillation episode could be correlated with an higher incidence of major adverse cardiovascular events at 1–year follow up.