The proposed research will provide an innovative and workable change to the medical decision-making process for patients presenting acutely to Emergency Departments with chest pain that might possibly be due to a heart attack. It is a randomised trial comparing current care with a new 'fast-track' pathway. Use of very early blood tests in a targeted low risk group of presenting patients, could possibly rule out heart attack approximately 10 hours earlier. This would then allow onward cardiac tests to be performed much sooner and make a tangible contribution to health care by preventing hospital admission and facilitating early discharge home. This outcome is beneficial for patients, who can be reassured earlier that heart attack has been ruled-out and who avoid the inconvenience and risks of hospital admission. It is beneficial for the health service, which avoids unnecessary admissions, duplication of staff activities and pressure upon urgent care services.