Stents Cardiovascular

Keywords Gene therapy, tissue reconstruction, injectable biopolymers, polymeric drug-elut-ing stents, cardiovascular polymers... 

Elevated homocysteine concentrations have been associated with an increased risk for cardiovascular disease in both epidemiologic and clinical studies.43 Several studies have evaluated the benefit of lowering homocysteine levels with folic acid supplementation. One study reported a reduction in major cardiac events with the combination of folic acid, vitamin B12, and vitamin B6 following PCI.44 However, a more recent study found an increased risk of instent restenosis and the need for target-vessel revascularization with folate supplementation following coronary stent placement.45 The role of folate in the management of IHD is currently unclear. 

For patients undergoing primary PCI, clopidogrel is administered as a 300-to 600-mg loading dose followed by a 75 mg/day maintenance dose, in combination with aspirin 325 mg once daily, to prevent subacute stent thrombosis and long-term cardiovascular events. 

Walter DH, Fichtlscherer S, Sellwig M, Auch-Schwelk W, Schachinger V, Zeiher AM. Preprocedural C-reactive protein levels and cardiovascular events after coronary stent implantation. J Am Coll Cardiol 2001 37 839-846. 

Zotarolimus (53 Endeavor stent) Sirolimus (33) Macrolide antibiotic Semi-synthetic NP Microbial Cardiovascular surgery Inhibits cell proliferation, preventing scar tissue formation and minimizes restenosis in angioplasty patients 467 74... 

Acute coronary syndrome For patients with acute coronary syndrome (unstable angina/non-Q-wave Ml) including patients who are to be managed medically and those who are to be managed with percutaneous coronary intervention (with or without stent) or coronary artery bypass graft (CABG), clopidogrel has been shown to decrease the rate of a combined endpoint of cardiovascular death. Ml, or stroke, as well as the rate of a combined endpoint of cardiovascular death. Ml, stroke, or refractory ischemia. 

Rapamycin (sirolimus), a macrolide antibiotic, has been used recently in organ transplantation for its potent immunosuppressive actions by inhibiting both cytokine mediated and growth factor mediated proliferation of smooth muscle cells and lymphocytes [55, 56]. In the RAVEL trial of non-acute single vessel lesions, the Sirolimus-eluting stent was compared to bare metal stent (BMS) in a 1 1 fashion [57]. One-year major adverse cardiovascular events and 6 month neointimal proliferation as assessed by late luminal loss (-0.01 0.33 mm in Sirolimus stent versus 0.80 0.53 mm in BMS) were improved. The Sirolimus-eluting stent thus virtually eliminated in-stent restenosis with no evidence of edge effect, dissection, or in-stent thrombosis. 

Hausleiter J, Kastrati A, Mehili J, et al. Predictive factors for early cardiovascular events and angiographic restenosis after coronary stent placement in small coronary arteries. J Am Coll Cardiol 2002 40 882-889. 

Shape-memory alloys (e.g. Cu-Zn-Al, Fe-Ni-Al, Ti-Ni alloys) are already in use in biomedical applications such as cardiovascular stents, guidewires and orthodontic wires. The shape-memory effect of these materials is based on a martensitic phase transformation. Shape memory alloys, such as nickel-titanium, are used to provide increased protection against sources of (extreme) heat. A shape-memory alloy possesses different properties below and above the temperature at which it is activated. Below this temperature, the shape of the alloy is easily deformed due to its flexible structure. At the activation temperature, the alloy can be changed by applying a force, but the structure resists this deformation and returns back to its initial shape. The activation temperature is a function of the ratio of nickel to titanium in the alloy. In contrast with Ni-Ti, copper-zinc alloys are capable of a two-way activation, and therefore a reversible variation of the shape is possible, which is a necessary condition for protection purposes in textiles used to resist changeable weather conditions. 

Gene therapy offers new possibilities for the treatment of cardiovascular diseases. This area of research has focused mainly on the treatment of postangioplasty restenosis, in-stent restenosis, and vein graft thickening. First clinical trials have shown that vascular gene transfer to humans is generally safe and well tolerated. Even... 

Limited data are available to link clopidogrel nonresponsiveness to the occurrence of thrombotic events. Matetzky et al. studied clopidogrel responsiveness in patients undergoing stenting for acute ST-elevation Ml. They found that patients who exhibited the highest quartile of ADP-induced aggregation had a 40% probability for a recurrent cardiovascular... 

PLATE LETS-lb studies, a 600 mg loading dose was associated with increased platelet inhibition compared to a 300 mg loading dose, In turn, increased platelet inhibition was accompanied by a decrease in the release of myocardial necrosis and inflammation (19,20). In a very recent study of 106 patients undergoing stenting, high post-treatment platelet reactivity was asso-ciated with an increased risk of recurrent cardiovascular events (22). 

Cuisset T Frere C, Quilici J, et al, High post-treatment platelet reactivity identified low-responders to dual antiplatelet therapy at increased risk of recurrent cardiovascular events after stenting for acute coronary syndrome, J Thromb Haemost 2006 4 542-549. 

I 8 De Scheerder I, Huang Y Schacht E. Now concepts for drug eluting stents, 6th Local Drug Delivery Meeting and Cardiovascular Course on Radiation and Molecular Strategies, Geneva, Switzerland, Jan 27-29, 2000. 

Sousa JE, Costa MA, Farb A, et al. Images in cardiovascular medicine, Vascular healing 4 years after the implantation of sirolimus-eluting stent in humans a histopathological examination, Circulation 2004 I 10( I ) e5—e6. 

Lally C, Dolan p Prendergast PJ. Cardiovascular stent design and vessel stresses a finite element analysis. J Biomech 2005 38 1574-1581. 

Nowak SA, Sabaj KM, Zielinski DA, et al. The effects of adding a polymer topcoat on the elution rate from drug-eluting stents (abstr), Cardiovascular Revascularization Therapeutics 2005 503-505. 

One hundred and seventy-three patients (134 males and 39 females), symptomatic patients with stable angina pectoris (Canadian Cardiovascular Society I, 2, 3, or 4) or unstable angina pectoris with documented ischaemia (Braunwald Class IB-C, IIB-C, or IIIB-C) or documented ischemia with a single de novo lesion in a coronary artery suitable for treatment with a single BiodivYsio DD OC-coated coronary stent preloaded with Batimastat of I 1, 15, 18, 22, or 28 mm length by 3.0, 3.5, or4.0-mm diameter were included in the study, providing they met the selection criteria. 

Flugelman MY Weisz A, Koren B, Fischer L, Lewis BS. Stent-based gene therapy from transfection efficiency to biological effect. Sixth International LDD R Local Drug delivery meeting and Cardiovascular Course on Radiation Molecular strategies—Abstract book, (abstr 26), January 28, 2000. 

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