This is a multicenter multidisciplinary study designed to investigate patient, provider, and system-related factors that are associated with the quality and safety of initial management for suspected ST-segment elevation myocardial infarction (STEMI) evolving for less than 12 hours in daily practice. The primary hypotheses are that delayed reperfusion therapy for suspected STEMI independently relates to provider practice patterns and system barriers. It is further postulated that non-compliance with target delays in implementing percutaneous coronary intervention (PCI) or fibrinolytic therapy is associated with worse in-hospital clinical outcomes. The secondary hypotheses are that the delivery of acute reperfusion therapy within target delays is associated with increased rates of false-positive cardiac catheterization laboratory activation, inadvertent fibrinolytic therapy, and bleeding events.