Understanding cardiac troponin part 2: early rule out of acute coronary syndrome

Chest pain of suspected cardiac origin is a very common emergency department presentation. Over the past decade, there has been an exponential growth in strategies that promote blood sampling at earlier and earlier time points after presentation to facilitate the rule out of acute coronary syndrome.In part 2 of this series, we examine key concepts from the recent literature with the aim of improving clinicians' understanding of the rule-out strategies available to them and provide a structured overview of strategies that facilitate discharge with blood testing over <3 hours.