Point-of-care i-STAT cardiac troponin I for assessment of patients with symptoms suggestive of acute coronary syndrome

Background: Few studies have investigated the role of cardiac troponin point-of-care (POC) testing for predicting adverse outcomes in acute coronary syndrome (ACS) patients. We investigated the use of a POC cTnI assay in ACS patients. Methods: We studied consecutive patients (n = 367) presenting with symptoms suggestive of ACS who were admitted through the emergency department. We measured plasma cTnI with the i-STAT assay. Patients were risk-stratified based on cTnI concentrations defined by the predetermined 99th percentile reference limit for plasma (0.04 mu g/L). Patients were followed for 60 days. We computed survival and event curves with the Kaplan-Meier method and compared risk stratification groups with the log-rank test. Results: Acute myocardial infarction (MI) was diagnosed in 8.1% of patients. Odds ratios and 95% confidence intervals for all-cause death (ACD), MI or ACD, MI or cardiac death, and cardiac death at 60 days were all statistically significant after adjustment for age, diabetes, hypertension, and history of renal failure as follows: 2.54 (1.24-5.20), P = 0.009; 2.76 (1.37-5.58)1 P = 0.003; 5.98 (1.65-21.7), P = 0.008; and 2.54 (1.24-5.20), P = 0.009. Kaplan-Meier curves showed early separation between patients with increased vs. reference concentrations before 30 days for ACD, MI or ACD, and MI or cardiac death. Conclusion: The i-STAT POC cTnI assay can be added to the list of assays for risk stratification. (c) 2006 American Association for Clinical Chemistry