Background The placement of stents in coronary arteries has been shown to reduce restenosis in comparison to balloon angioplasty. However, clinical use of intracoronary stents is impeded by the risk of subacute stent thrombosis and complications associated with the anticoagulant regimen. To reduce these complications, the hypothesis that systemic anticoagulation is not necessary when adequate stent expansion is achieved was prospectively evaluated on a consecutive series of patients who received intracoronary stents. Methods and Results From March 1993 to January 1994, 359 patients underwent Palmaz-Schatz coronary stent insertion. After an initial successful angiographic result with Conclusions The Palmaz-Schatz stent can be safely inserted in coronary arteries without subsequent anticoagulation provided that stent expansion is adequate and there are no other flow-limiting lesions present. The use of high-pressure final balloon dilatations and confirmation of adequate stent expansion by intravascular ultrasound provide assurance that anticoagulation therapy can be safely omitted. This technique significantly reduces hospital time and vascular complications and has a low stent thrombosis rate.

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Intracoronary Stenting Without Anticoagulation Accomplished With Intravascular Ultrasound Guidance

Background—There are limited studies of stent thrombosis in the modern era of second-generation stents, high-pressure deployment, and current antithrombotic regimens. Methods and Results—Six recently completed coronary stent trials and associated nonrandomized registries that enrolled 6186 patients (6219 treated vessels) treated with ≥1 coronary stent followed by antiplatelet therapy with aspirin and ticlopidine were pooled for this analysis. Within 30 days, clinical stent thrombosis developed in 53 patients (0.9%). The variables most significantly associated with the probability of stent thrombosis were persistent dissection NHLBI grade B or higher after stenting (OR, 3.7; 95% CI, 1.9 to 7.7), total stent length (OR, 1.3; 95% CI, 1.2 to 1.5 per 10 mm), and final minimal lumen diameter within the stent (OR, 0.4; 95% CI, 0.2 to 0.7 per 1 mm). Stent thrombosis was documented by angiography in 45 patients (0.7%). Clinical consequences of angiographic stent thrombosis included 64.4% incidence of death or myoc...

Stent Thrombosis in the Modern Era A Pooled Analysis of Multicenter Coronary Stent Clinical Trials

Background Vascular interventions that maximize initial lumen diameter provoke extensive neointimal hyperplasia but minimize its effects, causing long-term lumen size to be greater. Nevertheless, interventions such as endovascular stents, which increase lumen size above that achieved with balloon angioplasty, are subject to frequent thrombosis and restenosis. It has been unclear whether the response to stent-induced injury is determined solely by the degree of stent-induced arterial expansion or whether the geometric configuration of the stent or the material left in contact with the vessel wall also contribute. Methods and Results We examined the vascular response to steel stents deployed in denuded rabbit iliac arteries for 14 days. In one set of experiments, the effects of stent configuration were examined, holding diameter, mass, surface area, and stent surface material constant. In another set, stent surface material was changed, with mass, configuration, and diameter unaltered. Changing stent config...

Endovascular Stent Design Dictates Experimental Restenosis and Thrombosis

Percutaneous transluminal coronary angioplasty appears to be an effective alternative to coronary artery bypass surgery in patients whose coronary artery anatomy is suitable--that is, an individual with single (or, at most, double) vessel coronary artery disease whose stenoses are proximal, discrete, subtotal, concentric and noncalcified. Since emergent coronary artery bypass surgery is required in 5% to 7% of patients even when angioplasty is attempted by an experienced physician, the patient should be an acceptable candidate for surgery from both a cardiac and noncardiac standpoint. Unfortunately, ideal angioplasty candidates are a distinct minority among those with coronary artery disease. If the procedure is reserved for ideal (or nearly ideal) candidates, the rate of success should approach 75% to 80%, and the incidence of major complications should be below 10%. Although the procedure appears to be effective in alleviating angina, it is unlikely that it will exert a beneficial effect on survival when compared to either medical therapy or coronary artery bypass surgery.

Percutaneous transluminal coronary angioplasty.

http://www.sarasotaanesthesia.com/reading/literature/Stent_Wilson.pdf

Connie A. Zimmerman

Papers

Thrombosis of a flexible coil coronary stent: frequency, predictors and clinical outcome.

Intracoronary stenting compared with conventional therapy for abrupt vessel closure complicating coronary angioplasty. A matched case-control study