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Cardiology Core Curriculum - part 3

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Tham khảo tài liệu 'cardiology core curriculum - part 3', y tế - sức khoẻ, y học thường thức phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Cardiology Core Curriculum Intracoronary stents There is a wide variety of intracoronary stents available for deployment in the coronary arteries after PTCA. These will reduce the rate of restenosis as compared with PTCA alone when introduced into vessels of sufficiently large caliber. Two randomized trials compared Palmaz-Schatz stent placement following PTCA versus PTCA alone for elective procedures in large vessels 3-0 mm and convincingly demonstrated that angiographic restenosis and need for repeat interventions were lower in stented patients. This benefit was derived at the cost of longer hospital stays and a greater incidence of vascular complications in the stented group because of the need for aggressive anticoagulation following stent placement. The incidence of stent thrombosis for which a patient is at risk for approximately 30 days following the procedure was less than 4 in those studies. Because stent deployment strategies now include only aspirin and clopidogrel for 1 month instead of a combination of aspirin and coumadin there are currently no disadvantages to using stents other than cost. Although the incidence of lesion recurrence is decreased with stenting in-stent restenosis is a difficult situation to treat because of a high incidence up to 70 of a second restenosis especially if the renarrowing involves the majority of the stent length. Intravascular radiation brachytherapy using either p or Y emitters have been demonstrated to reduce conclusively the incidence of recurrent instent restenosis although at a greater risk for stent thrombosis. Consequently patients receiving coronary brachytherapy are treated with aspirin and clopridogel for 6-9 months rather than the usual 30 days. A promising alternative is the use of coated stents which locally release antiproliferative pharmaceuticals continuously over several weeks. Initial results using paclitaxel and sirolimus eluting stents have shown a marked reduction in in-stent restenosis although .