Abstract 18745: Major Adverse Cardiac Events After Non-cardiac Surgery Following Previous Percutaneous Coronary Intervention With Stent Implantation

Introduction: It is estimated that 5-16% of patients (pts) previously treated with percutaneous coronary interventions (PCI) and stent implantation will present for elective non-cardiac surgery (NCS) within 1 year. Despite ACC/AHA recommendations on antiplatelet therapy (ATP) the incidence of perioperative major cardiovascular events (MACE) is high. The objective of this multi-center prospective, cohort study was to determine if APT continued throughout perioperative period decreases the incidence of MI in this population and to determine the mechanism of MACE in post-PCI pts undergoing NCS. Hypothesis: There is an association between inadequate platelet inhibition and the incidence of MACE in pts undergoing NCS after previous PCI. Method: After REB approval pts after previous PCI scheduled for elective NCS were recruited. The primary outcome was Major Adverse Cardiac Event (defined as MI, stent thrombosis, need for revascularization or 30 day mortality). The incidence of MI was blindly adjudicated in duplicate using the 3 rd Univ. definition of MI. Troponin levels were measured every 8h for 2 days, then once daily until discharge in addition to ECG measurements. All pts patient was followed up for any clinical symptoms of MI. The location of MI was also judged based on its location (area of stent or not). The platelet inhibition by aspirin (ASA) and/or clopidogrel was measured using the Platelet Mapping Assay (PMA) performed preoperatively, 1h and 24h after surgery. Results: A total of 201 pts were recruited. The incidence of MACE was 21%. Additionally, 11 pts (5%) had isolated troponin elevation. The location of the MI occurred frequently in the area of the stent placement (71%). Pts. exposed to ASA with 5 days of surgery had better platelet inhibition than pts no exposed. There was no difference in platelet inhibition between pts suffering from MI and those who did not. Several factors were associated with increased MACE. These included higher Revised Cardiac Risk Index and pre- and post-operative anemia. 30 patients (15%) suffered from major bleeding complications. Conclusions: Results of this study indicated that use of ASA, or its withdrawal, was not associated with MACE in post PCI patients undergoing NCS.