There are key differences today in clinical practice regarding perioperative management of post-PCI patients on DAPT undergoing NCS. Moreover, there are significant differences between bridging agents, and improved safety of current-generation DES. Given the significant limitations of current studies a well-designed registry to study current U.S. practice patterns and the bleeding or ischemic risks associated with the various perioperative DAPT management strategies including bridging and no bridging will significantly add to the understanding of the current problem and associated risks of patients. These data could form the basis for conducting future randomized clinical trials (RCTs) in this area. NCS in post-PCI patients on chronic DAPT presents a complex interaction of both ischemic and bleeding risks. The MARS registry will study the area of perioperative antiplatelet therapy management through a multicenter observational national registry designed to collect pre-operative, intra-operative and post-operative clinical strategies, therapeutic interventions and outcomes data. This proposal outlines the role of a highly experienced clinical trial team to conduct a multicenter prospective registry. This question is highly relevant to a diverse group of medical providers and millions of patients in the US and around the world; this will be the first such U.S. registry to address this critically important public health issue. Study objectives: i. To collect data on contemporary clinical practice in the U.S. on managing post percutaneous coronary intervention (PCI) DAPT in patients scheduled to undergo NCS and CS. ii. To assess ischemic and bleeding endpoints in this group of patients during the study period. iii. To generate initial data to plan for future large-scale randomized clinical trials on perioperative management of DAPT.