As Markers of Myocardial Damage

Troponins, as markers of myocardial damage, take time to rise after an ischaemic event, so blood samples taken in the first few hours after symptoms have lower sensitivity than those taken later.

However, recent data suggest that newer assays have better early sensitivity and, if a low threshold for a positive test is used, a negative troponin can effectively rule out AMI as early as 6 hours after worst symptoms in a patient with low risk chest pain.11

Certainly it seems reasonable to conclude that a patient with low risk chest pain, who has no detectable troponin in a sample taken at least 6 hours after their worst symptoms, will gain little benefit from hospital admission.11