This trial is designed as a prospective, multi-center, observational study of "all-comers" eligible adult subjects presenting to participating emergency departments with symptoms suggestive of acute coronary syndrome (ACS)

This trial is designed as a prospective, multi-center, observational study of "all-comers" eligible adult subjects presenting to participating Emergency Departments (EDs) with symptoms suggestive of ACS and/or myocardial ischemia. Subjects presenting with symptoms suggestive of ACS will be screened and approached for consent for study enrollment by trained personnel.

After obtaining written informed consent, subjects will have up to 4 blood samples collected for cTnI testing using the Meritas Troponin I test and Meritas point-of-care (POC) Analyzer. Blood draws and testing will occur at 4 intervals over 24 hours.

Inclusion Criteria:

1. The informed consent must be signed by the subject, or the subject's legal authorized representative.
2. 21 years of age or greater at the time of enrollment
3. Subjects presenting to the ED with any symptoms suggestive of ACS and/or myocardial ischemia, such as but not limited to: subjects currently having chest pain, pressure or a burning sensation across the precordium and epigastrium, pain that radiates to neck, shoulder, jaw, back, upper abdomen and either arm.

Exclusion Criteria:

1. Informed consent form not signed
2. Age <21 years
3. Known pregnancy -

Approximately 1000 to 1500 adult subjects presenting to emergency departments (ED) with symptoms suggestive of acute coronary sydrome (ACS) and/or myocardial ischemia