Implementation of a Sensitive Troponin I Assay and Risk of Recurrent Myocardial Infarction and Death in Patients With Suspected Acute Coronary Syndrome

 Increasing the sensitivity of troponin assay can improve early diagnosis of myocardial infarction  Only values at or above the diagnostic threshold of 0.20 ng/mL  Provide assess to better intervention for patients with suspected acute coronary syndrome

 Determine the effect of sensitive assay on the rate diagnosis of MI  Whether small increases in troponin predict the future risk of adverse clinical outcomes  How lowering the diagnostic thresholds would affect clinical outcomes

 Original diagnostic threshold was 0.20 ng/mL with laboratory coefficient of variation of <10%  Assay was reformulated to achieve a greater analytical sensitivity of 0.01 ng/mL

 Patients who were admitted with suspected ACS to Royal Infirmary of Edinburgh  Validation period: February 1 to July 31, 2008  Only concentrations above the original diagnostic threshold >= 0.20 ng/mL were reported  Implementation period: February 1 to July 31, 2010  Concentrations above >= 0.05 ng/mL were reported in the implementation phase

 3434 patients met the inclusion criteria but 1342 patients had at least 1 exclusion criteria  Total study population was 2092 patients  Inclusion criteria:  Symptoms of chest pain of suspected cardiac origin measurement of plasma troponin I concentration on admission

 Exclusion criteria:  Noncardiac chest pains  Tachyarrhythmia  Anemia  Severe valvular heart disease  Pericarditis  Cocaine use

 The increase sensitivity allowed for the detection of MI by 29%  Identified patients who were at highest risk of recurrent MI and death  Lowering the diagnostic threshold allowed for 50% reduction in the rate of death or recurrent MI in the subgroup of patients  Patients are from a homogenous population