Coronary Artery Stents: Part I. Evolution of Percutaneous Coronary Intervention

Abstract

The subspecialty of interventional cardiology has made significant progress in the management of coronary artery disease over the past three decades with the development of percutaneous coronary transluminal angioplasty, atherectomy, and bare-metal and drug-eluting stents (DES). Bare-metal stents (BMS) maintain vessel lumen diameter by acting as a scaffold and prevent collapse incurred by angioplasty. However, these devices cause neointimal hyperplasia leading to in-stent restenosis and requiring reintervention in more than 20% of patients by 6 mo. DES (sirolimus and paclitaxel) prevent restenosis by inhibiting neointimal hyperplasia. However, DESs also delay endothelialization, causing the stents to remain thrombogenic for an extended, yet unknown, period of time. Late stent thrombosis is associated with a 45% mortality rate. Premature discontinuation of antiplatelet therapy, particularly clopidogrel, is the strongest predictor of stent thrombosis. Sixty percent of patients receive stents for off-label (unapproved) indications, which also increases the frequency of stent thrombosis. Clopidogrel and aspirin are the cornerstone of therapy in the prevention of stent thrombosis in both BMS and DES. Recommendations pertaining to the optimal duration of dual-antiplatelet therapy have been debated. Both the Food and Drug Administration and the American Heart Association/American College of Cardiologists, in association with other major societies, have made recommendations to extend the duration of dual-antiplatelet therapy in patients with DES to 1 yr. The 6-wk duration of dual-antiplatelet therapy in patients with BMS remains unchanged. All patients with coronary stents must remain on life-long aspirin monotherapy. Since the introduction of percutaneous transluminal coronary angioplasty for the treatment of coronary atherosclerosis, the practice of percutaneous coronary intervention has undergone a dramatic transformation from simple balloon dilation catheters to sophisticated mechanical endoprostheses. These advancements have impacted the practice of perioperative medicine. In this series of two articles, in Part I we will review the evolution of percutaneous coronary intervention and discuss the issues associated with percutaneous transluminal coronary angioplasty and coronary stenting; in Part II we will discuss perioperative issues and management strategies of coronary stents during noncardiac surgery.

Multiple Roles of Connexins in Atherosclerosis- and Restenosis-Induced Vascular Remodelling

“…Restenosis is due to an exaggerated cellular response at the site of the intervention, leading to formation of the neointima and to re-occlusion of the artery [8]. The elaboration of drug-eluting stents has helped tremendously to prevent restenosis by inhibiting neointimal hyperplasia, but drug-eluting stents also delay re-endothelialization, leading to late in-stent thrombosis [115]. The molecular pathways implicated in all of these phenomena remain poorly understood.…”

The Perioperative Management of Treatment With Anticoagulants and Platelet Aggregation Inhibitors

“…Stent thrombosis is a sudden thrombotic occlusion of a coronary stent leading to myocardial infarction, which is fatal in up to 75% of cases (34,35).…”

Pain Management After Thoracic Surgery

“…Patients receiving drug eluting stents require aspirin and clopidogrel for at least 12 months. All patients with stents in situ require aspirin for life [7,9,222]. Dual-antiplatelet therapy is a contraindication to epidural analgesia [6].…”