Usefulness of a 2-hour Delta Troponin-I During the ED Identification and Exclusion of Acute Myocardial Infarction

Inclusion Criteria: 1. Adult patients 18 years of age or older 2. Chest pain suspicious for ACS 3. Absence of ST-segment elevation AMI (STEMI) or STEMI equivalent on the initial ECG 4. Baseline i-STAT troponin less or equal to 1.0 ng/ml 5. Enrollment initiated before 2 hour 'delt' troponin value available for review 6. Ability and willingness to participate and cooperate with telephone follow-up evaluations Exclusion Criteria: 1. ST-elevation or other ECG criteria that results in the diagnosis of AMI and results in patient being sent for percutaneous coronary interventions (PCI) or being treated with thrombolytics 2. Patients with chest pain not deemed to warrant cardiac screening 3. Blunt chest trauma 4. Tachyarrhythmia (ventricular tachycardia, supraventricular tachycardia, or rapid atrial fibrillation) 5. Cardiac Arrest prior to arrival 6. Hemodynamically unstable patients 7. Pulmonary edema requiring CPAP, BIPAP, or mechanical ventilation 8. Baseline i-STAT troponin measurement greater than 1.0 ng/ml 9. Baseline and 2-hour i-STAT Troponin measurements not obtained 10. Patient (or Legal Representative) unable or unwilling to provide written informed consent 11. Subject unwilling or unlikely to comply with study procedures, including protocol-specific blood sampling 12. Subject unwilling, unable, or deemed unlikely to respond or participate in telephone follow-up 13. Vulnerable populations as deemed inappropriate for the study