This prospective, multicentre, observational study aims to test pre-operative platelet function when taking anti-platelet medications. The investigators are using a simple bedside blood test called Thromboelastography (TEG) and Platelet Mapping Assay (PMA). The investigators will then follow the patient throughout their hospital stay for any major cardiac complications (MACE) after surgery (peri-operative). The investigators hope to determine if there is an association between how well platelets were inhibited by these drugs before surgery and MACE during the perioperative period, 30 day, and one year follow-up. Also, the response of various people to anti-platelet medications and their chances of getting a major adverse cardiac outcome are determined by their genetic makeup. The investigators will try to determine if certain genes are associated with higher cardiac risk.