The study is a prospective observational study focused on monitoring the effects of various treatment options for acute coronary syndrome (ACS) patients by measuring serum neopterin levels. Serum neopterin is a marker for measuring macrophage activation. Prior studies have illustrated that there are elevated serum neopterin levels in ACS. The investigators' study focused on comparing different treatment arms with regard to their neopterin levels and correlating neopterin levels to the Thrombolysis in Myocardial Infarction (TIMI) risk score. Patients enrolled are those with ACS. Blood samples are drawn at presentation, and at 72 hours after admission, or at office visits and at 72 hours later. Neopterin levels are measured via a commercially available assay.