生物谷援引：根据一项新研究指出，接受经皮冠状动脉介入（PCI）的ST段上升心肌梗塞（STEMI）的病患，预先以两倍剂量的clopidogrel（Plavix）治疗，可以降低心脏血管事件死亡风险近一半。
研究人员发现在装设心血管支架前，给予患者至少600毫克的 clopidogrel，而不是标准300 毫克之剂量，可以减少装设心血管支架之主要并发症：血栓形成的风险。此外，大剂量并不会增加严重出血的风险。这项研究有重要的临床意义。
抗血栓形成的治疗目标是避免患者于PCI之后发生血栓形成的并发症，并且使手术后的出血减到最小并节省治疗费用。通常第一次给予Clopidogrel的剂量为300毫克，之后每天投予75毫克；所有病患同时接受由医师决定的血栓溶解治疗以及aspirin；接受血栓解治疗的病患同时也使用48小时的heparin。
这项研究将于2007 年5月9 日- 12 日于奥兰多举行的第30届美国心血管造影和介入治疗学会年会中提出。
（编译/姜欣慧） (资料来源 : Bio.com)
英文原文：
High-dose Anticlotting Drug Cuts Heart Attack, Death Risk In Half
05/14/07 -- Pretreatment with double-dose anticlotting medication just before percutaneous coronary intervention (PCI) cuts the combined risk of heart attack and cardiac death by half, according to a new study.
Researchers found that giving patients at least 600 mg of clopidogrel before stenting, rather than the standard 300-mg dose, halved the risk of major complications associated with blood clotting, or thrombosis. In addition, the higher dose did not increase the risk of serious bleeding.
"This research has important clinical and cost implications," said Giuseppe G. Biondi-Zoccai, M.D., an assistant professor of cardiology at the University of Turin, in Turin, Italy. "The goal of antithrombotic management for PCI is to maximize protection from thrombotic complications during and shortly after PCI, while minimizing bleeding and costs."
Clopidogrel interferes with the action of platelet cells, which stimulate the formation of blood clots. Interventional cardiologists give patients a loading dose of this medication before PCI to protect against blood clotting. After the procedure, most patients take a lower daily dose (75 mg) for up to a year, depending on the type of stent used to prop open the clogged coronary artery.
To evaluate the effect of the clopidogrel loading dose, researchers from University of Turin and Virginia Commonwealth University, in Richmond, performed a meta-analysis of data from 10 studies involving more than 1,500 patients. Roughly half of the patients were pretreated with 300 mg of clopidogrel and the other half with 600 mg. A few received either 450 mg or 900 mg of clopidogrel.
Overall, pretreatment with high-dose clopidogrel (600 mg or more) was associated with a 50 percent reduction in the risk of cardiac death or nonfatal heart attack, both during the initial hospitalization and within 30 days of the PCI procedure, a finding that was highly statistically significant (p=0.009). There was no statistically significant increase in major or minor bleeding (p=0.55 and p=0.98, respectively). Findings remained the same when the analysis was restricted to 7 randomized controlled trials only. Further analysis showed that the higher the underlying risk of complications related to blood clotting, the greater the benefit from high-dose clopidogrel.
The study was presented at the 30th Annual Scientific Sessions of the Society for Cardiovascular Angiography and Interventions, May 9--12, 2007, in Orlando, FL by Antonio Abbate, M.D., an assistant professor of medicine, Virginia Commonwealth University, Pauley Heart Center, Richmond, VA.
Source: Society for Cardiovascular Angiography and Interventions
