Which is the best way to differentiate between stable angina and NSTEMI?

Cardiac markers are used in the diagnosis and risk stratification of patients with chest pain and suspected acute coronary syndrome (ACS). The cardiac troponins, in paicular, have become the cardiac markers of choice in acute coronary syndrome which includes NSTEMI. However, in chronic Stable angina, the symptoms arise on exeion/emotion or post-prandially and have characteristic ST-segment depression on exercise testing. Cardiac biomarkers are normal as no cell death occurs in this case.