在每天服用的抗血小板藥物clopidogrel (Plavix)配合著阿斯匹靈服用，將能降低患有心肌梗塞與心血管疾病，且進行血管造形術與移填模手術病患的死亡率達到百分之三十一。這些發現，公佈在八月十八日的The Lancet期刊上，因其潛在的公共衛生價值，馬上被進一步追蹤報導。這研究是根源於一來自clopidogrel研究的子團體。來自這項試驗的成果最先是在今年初的美國心臟學院會議中被報導出來，而其他更進一步的細節分析則是在這禮拜的The New England Journal of Medicine期刊中發表。
One-Year Benefits Seen in Angioplasty, Stenting Patients
By Aman Shah, MD
WebMD Medical News
Reviewed by Michael W. Smith, MD
Aug. 16, 2001 -- A daily dose of the antiplatelet drug clopidogrel (Plavix) with a standard aspirin chaser cuts the risk of MI and cardiovascular death by 31% in patients who undergo angioplasty or coronary stenting. The findings, published in the Aug. 18 issue of The Lancet, were fast-tracked due to their potential public health implications.
The study is based on a subgroup of patients from a larger clopidogrel study. Results from the larger CURE trial were first reported earlier this year at the American College of Cardiology meeting, and a more detailed analysis of those results is published this week in TheNew England Journal of Medicine.
Co-author Salim Yusuf, DPhil, tells WebMD that cardiologists asked for the separate analysis because there is heightened interest in "performing percutaneous coronary interventions (PCI) and in being a little more aggressive with these interventions." The larger study lumps together results from people who were treated with bypass surgery and those who received PCI. "Everyone was asking us, 'What about PCI?' ... This paper is a confirmation of the findings presented in Orlando [at the ACC meeting]," says Yusuf, professor of cardiology at McMaster University in Toronto.
The Lancet study reports findings from 2,658 patients who were diagnosed with non-ST elevation acute coronary syndrome and underwent PCI. The patients were randomized to aspirin plus clopidogrel or aspirin and placebo for a median of 6 days before treatment in a double-blind fashion. All subjects were then treated with thienopyridine, of which clopidogrel is a derivative, for about 4 weeks; clopidogrel was then restarted 4 weeks after treatment for up to a year (median, 8 months).
The larger study showed that 11.5% of patients in the placebo arm met the composite primary end point of cardiovascular death, MI, or revascularization, compared with 9.3% of the clopidogrel patients. Looking just at the patients who underwent PCI, 4.5% of the patients taking clopidogrel met the primary end point by the 1-year point, compared with 6.4% of the patients taking placebo. There was no difference in bleeding between the two groups.
In an accompanying editorial, R.H. Stables, DM, consulting cardiologist at Royal Liverpool University, writes that while it is clear that clopidogrel offers a benefit in the short term -- within the first 30 days after the procedure -- long-term benefit is not so clear. "This is standard treatment now," he tells WebMD. "But I think the jury is still out on continuing the drug long term."
Yusuf and lead author Shamir R. Mehta, MD, say that Stables is only partly right in his criticism. The PCI study "is not powered to show significance" at 1 year, says Mehta, professor of cardiology at McMaster University in Toronto. For that reason, PCI has to be considered in the context of the larger CURE study, says Yusuf.
Although Yusuf says the jury is still out on whether to extend clopidogrel treatment beyond a year, he favors treatment for at least a year. He tells WebMD that studies that established a survival benefit for daily aspirin use were "all 1-year studies, but we are all fairly comfortable in extending aspirin therapy indefinitely." In his own practice, he uses clopidogrel for a year and then assesses risks at the 1-year mark. "In high-risk patients, I will continue clopidogrel beyond a year," he says.
One big difference between clopidogrel and standard aspirin is cost: Clopidogrel costs about $3 per day. Yusuf admits that he, too, is concerned about the cost, but he points out that $1,000 a year is less than the cost of bypass surgery or a repeat PCI.