It was compared method of highly sensitive troponin I determination that was introduced into cardiac center practice with other previously applied techniques. The study was conducted using chemiluminescent immunoassay on ChemiFlex microcorpuscles. Two quantitative methods of troponin I level measurement were compared namely ARCHITEST STAT Troponin I and ARCHITEST STAT high sensitive Troponin I («Abbott»). It was shown that the use of test for highly sensitive troponin I (ARCHITEST STAT high sensitive Troponin I) increased number of patients with acute coronary syndrome who underwent invasive treatment and those who needed for medical assistance in target time period. It was concluded that ARCHITEST STAT high sensitive Troponin I technique has higher sensitivity, specificity and diagnostic value of both positive and negative results. Also use of reduced diagnostic threshold for myocardial necrosis increases myocardial infarction detection rate.