Intracoronary artery predominant method of percutaneous revascularization because of its relative ease of use and lower frequency of clinical and angiographic restenosis compared to balloon angioplasty.
Coronary stents are metallic scaffolds that prevent vessel recoiling and reduce the risk of arterial restenosis.
Coronary artery stents are currently used in more than 90% of patients undergoing PCI because they improve procedural success and clinical outcomes.
Indicated over percutaneous coronary angioplasty for the treatment of de novo or restenotic lesions situated in large vessels 3 mm or greater in size.
Preferred method of percutaneous revascularization due to improved procedural safety as compared with balloon angioplasty and reduced rates of restenosis.
The frequency of restenosis may be more than 30% in patients with diabetes, small coronary vessels and long lesions.
There are two types of coronary stents available: bare metal and drug eluting..
The use of sirolimus-eluting stent reduces the rates of restenosis and associated clinical events compared the use of standard stents.
In multivessel disease offers the same degree of protection against death, stroke and myocardial infarction.
Necessitates fewer repeated revascularization procedures than does angioplasty without stenting.
Lowers the rates of abrupt closure, emergency coronary artery bypass graft surgery and restenosis, but does not prevent myocardial infarction or death at six months.
Among patients recently undergone coronary artery stent placement aspirin and clopidogrel should be given in combination for up to 1 year.
Dual antiplatelet therapy is recommended for 4 to 6 weeks after the placement of a bare metal stent and for 12 months after a drug eluting stent placement to minimize the risk of stent thrombosis.
Approximately 5% patients who undergo stenting of coronary arteries require surgery within a year of the stent placement.
Following a stent placement and antiplatelet treatment, urgent surgeries may be required during the critical re-endothelialization period: it is generally accepted to withdraw antiplatelet agents, 7 to 10 days before a surgical procedure or endoscopic procedure to lessen the risk of excessive bleeding.
Premature discontinuation of antiplatelet drugs, markedly increases the risk of stent thrombosis with possible catastrophic consequences of myocardial infarction and death.
Premature withdrawal of antiplatelet drugs following stent placement increases the risk of perioperative cardiac death rate of 5 to 10 fold, with an average incidence of death 30%.
For patients that develop stent thrombosis the case fatality rate is about 25%.
For patients who have stents and two or beyond the critical period of stent endothelization and to require surgery is continuing clopidogrel and continuing aspirin is an option: however, stopping clopidogrel during the critical period places the patient at increased risk of stent thrombosis, even if aspirin is continued, aspirin alone is not sufficient to prevent stent thrombosis in patients who are not beyond the critical period of stent re-endothelialization.
Overall the best option for the patient who requires a surgical procedure is to not interrupt the antiplatelet therapy for patients with a drug eluting stent and who require surgery within 12 months of its placement, and also the drugs should be continued for patients with a bare metal stent within six weeks of placement of the stent.