Background: Troponin I (CnTi) is the biomarker of choice for diagnosis of acute myocardial infarction (AMI). It is preferred due to sensitivity and specificity of heart cell necrosis although it has a slow rise and fall requires multiple testing (0, 4, and 8 hours) before rule out. Currently, all patients have same threshold troponin level. No variation for different patient populations. Rule in defined as any level >99% of normal population (0.10 ng/μL) Study Objectives: Determine whether there are identifiable patient characteristics (age, sex, race) that are associated with differences in peak troponin level. Methods: Study was conducted at large urban, teaching hospital in Washington, DC. All patients presenting to ED from 11/2009-12/31/11 and admitted with final ICD-9 diagnosis of sub-endocardial infarction (410.71) Key variables (age, sex, race, length of stay) automatically extracted. Peak cTnI measured in ED and/or inpatient floors were manually extracted to the database. Exploratory data analysis, simple linear, and multivariable regression were performed using Stata v. 12. Results: 460 total patients. Five patients excluded due to death in emergency department and no troponin measurements. 13 patient were included twice due to second visit to ED. Peak cTnI showed log-normal distribution. Required natural logarithm transformation for further analysis. Multivariate analysis comparing peak troponin to sex are shown in table 2, figure one. There was no-statistical difference between male and female peak troponin levels. The same analysis was completed for race and age. From the initial statistical analysis only race influenced peak cTnI with African-Americans having a lower measured value then other races.Tabled 1 Conclusion: Our study is the first known to look at differences in troponin levels in patients with known NSTEMI. Race was the only characteristic to show statistically significant differences in peak cTnI level with African-Americans having a lower peak than other races. Diagnostically treated levels of cTnI may need to be modified to include differences between race.