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

Primary Aims: 1) Demonstrate that a 2hr delta troponin as measured by the i-STAT platform can reliably identify and exclude MI on the initial ED evaluation. 2)Demonstrate that a 2hr delta troponin is useful in the discrimination AMI versus non-AMI conditions in patients with low abnormal baseline Troponin-I values.

Secondary Aims: 1) Demonstrate that a positive 2-hr delta troponin-I identifies patients at highest risk for 30 day ACE. 2) Other Secondary aims TBD.

Inclusion criteria

• Adult patients 18 years of age or older
• Chest pain suspicious for ACS
• Absence of ST-segment elevation AMI (STEMI) or STEMI equivalent on the initial ECG
• Baseline i-STAT troponin less or equal to 1.0 ng/ml
• Enrollment initiated before 2 hour 'delt' troponin value available for review
• Ability and willingness to participate and cooperate with telephone follow-up evaluations

Exclusion criteria

• 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
• Patients with chest pain not deemed to warrant cardiac screening
• Blunt chest trauma
• Tachyarrhythmia (ventricular tachycardia, supraventricular tachycardia, or rapid atrial fibrillation)
• Cardiac Arrest prior to arrival
• Hemodynamically unstable patients
• Pulmonary edema requiring CPAP, BIPAP, or mechanical ventilation
• Baseline i-STAT troponin measurement greater than 1.0 ng/ml
• Baseline and 2-hour i-STAT Troponin measurements not obtained
• Patient (or Legal Representative) unable or unwilling to provide written informed consent
• Subject unwilling or unlikely to comply with study procedures, including protocol-specific blood sampling
• Subject unwilling, unable, or deemed unlikely to respond or participate in telephone follow-up
• Vulnerable populations as deemed inappropriate for the study