Secondary outcomes will be change in chest pain score for patients treated for STEMI in the field and in-hospital mortality. Chest pain is assessed on a 11-point Numeric Rating Scale (NRS). The initial pain score is assessed and documented by paramedics. The same NRS is used by the triage nurse upon ED arrival. A priori, a decrease of 1.39 will be considered the minimum clinically significant difference (MCSD) based on prior literature. Planned subgroup analysis for these outcomes will be patients requiring PCI for proximal right coronary artery lesion on catheterization.