Rapid safe approach to determining which patients who present to the Emergency Department with chest pain of a possible cardiac origin may be safely discharged.

Observational. Prospective recruitment of patients identified by our protocol as non- high risk are followed up at thirty days from their index presentation to the Emergency Department (ED). Patients are eligible for the protocol if they have chest pain, a non-diagnostic electro-cardio-gram (ECG) and no immediate non-cardiac cause. Based on the clinical presentation a Senior ED Physician assesses the pre-test risk for a thirty day event. High sensitivity cardiac troponin T is taken as close to arrival time as possible with a second troponin at two hours, based on serial clinical observation ECG and High sensitivity troponin testing a post test judgement of high or non-high risk is made by a senior ED physician. An initial troponin T of <14ngm/l with a two hour delta of 5 or less is non-high risk, an initial troponin of between 14 and 52ngm/l with a delta of <5ngm/l equals non-high risk a value >52ngm/l equals high risk. Senior physician gestalt trumps the protocol.