This question always creeps in any coronary care unit.
Often times , there is a significant histo-pathological overlap between severe degrees of Ischemia* and myocyte necrosis . (What is called micro infarcts, lacunar infarcts, make us over diagnose MI). It is not yet clear , whether leaky myocyte cell membrane can release free cytoplasmic enzymes without actual cell necrosis.
Fortunately , there is not much .These bio markers are primarily used as prognostication tools .Many of these patients need to undergo early revascularisation. However , It is unwise,to get alarmed by just Troponin positivity in an other wise comfortable ACS patient.
* Some call severe degrees of Ischemia as Injury ! It is an old thought based entirely on ECG .There is no specific cellular equivalent of electrical injury current !