 This clinical trial is being conducted to 1 evaluate the possible usefulness of a panel of cardiac markers in assessing emergency department patients with possible acute coronary syndrome, 2 evaluate the usefulness of BNP in assessing emergency department patients with possible acute coronary syndrome, 3 determine if BNP can be used to predict adverse events during hospitalization and in the emergency department, and 4 evaluate how a Point-of-Care testing platform affects resource utilization in the emergency department. 