1. Clinically based risk stratification tools used in non-cardiac surgery (e.g., Revised Cardiac Risk Index) are of moderate utility and assign patients only to broad risk categories. This study will examine the usefulness of pre-operative biomarkers (BNP, HbA1c, and others) in supporting cardiac risk stratification and will address the question: Is there a set of preoperative criteria that can accurately inform the decision to monitor troponin postoperatively?