Cardiac Risk and Stent Effect on Adverse Perioperative Hawn 1 Anticipated Impact: Veterans needing surgery after cardiac stent implantation face a poorly defined increased risk of adverse peri-operative events and mortality due to the risk for acute stent thrombosis with cessation of antiplatelet therapy. As a consequence, surgery may be significantly delayed or modified to attenuate the perceived risk. The current rate of surgery after stent implantation is unknown. Our study will add much needed knowledge regarding the need for subsequent surgery following stent implantation, the risk of adverse peri-operative events and mortality in patients undergoing surgery. Furthermore, we will assess adoption and effectiveness of current guidelines regarding surgery in patients with cardiac stents. These findings will allow for more informed decision making for veterans needing surgery and lay the groundwork for future trials on management of antiplatelet therapy in this patient population. Project Background: Percutaneous coronary intervention and stenting of critical stenosis with drug eluting stents has increased stent patency rates. However, acute stent thrombosis due to cessation of antiplatelet therapy, especially within the first year post stent placement, is a known occurrence. More recently, there have been reports of acute stent thrombosis in the peri-operative period, leading to guidelines recommending the delay of surgery for 12 months post stent placement, or if more urgent surgery is necessary, to continue antiplatelet therapy through the peri-operative period. Standard practice is to stop antiplatelet therapy 5-7 days prior to surgery to prevent bleeding complications associated with invasive procedures. Empiric evidence about the rate of subsequent surgical procedures and their complications of acute stent thrombosis, major adverse cardiac events and bleeding complications for patients with drug eluting or bare metal stent undergoing surgery is absent. Furthermore, there is no evaluation of whether the risk for surgical patients decreases after the one year period to warrant delaying surgery. Project Objectives: To determine the rate of subsequent surgical procedures in patients after cardiac stent implantation. To assess whether a) time between cardiac stent and surgical procedure, and b) type of cardiac stent is associated with adverse perioperative events compared with controls. To assess current beliefs and practices of cardiologists, anesthesiologists and surgeons regarding the risk of stent thrombosis and bleeding in the peri-operative period. To evaluate whether surgery performed within the current guidelines is safer than those performed outside the guidelines. Project Methods: We propose a detailed analysis of surgical outcomes for patients identified in the Cardiovascular Assessment Reporting and Tracking system for Cath Labs (CART-CL) national database that underwent subsequent non-cardiac surgical procedures and were tracked in the National Surgical Quality Improvement Program (NSQIP) database. We will also perform a quantitative survey to characterize knowledge, attitudes and beliefs concerning the current guidelines and describe the concordance among surgeons, anesthesiologists and cardiologists.

Cardiac Risk and Stent Effect on Adverse Perioperative Hawn 1 Using a retrospective cohort study design, we will estimate the incidence of subsequent surgical procedures in a cohort of patients that have had cardiac stent implantation (Aim1). To assess the risks associated with cessation of antiplatelet therapy in this cohort, we will compare their surgical complications and mortality with a non-stent surgical cohort (Aim 2). We will determine whether adherence to current American College of Cardiology guidelines attenuate the risk of subsequent surgical procedures in patients with cardiac stent implantation (Aim 3). To further understand guideline adherence, we will perform a survey of cardiologists, anesthesiologists and surgeons to assess their knowledge, attitudes and beliefs (Aim 3). These finding will guide future intervention studies on management of antiplatelet therapy in this patient population.