美比较了阿司匹林vs华法令减少脑卒中风险的效果

根据一项最新研究发现：当用于减少大脑动脉不完全阻塞患者血液凝结的时候，阿司匹林与华法令共同应用的副作用较少。

阿司匹林和华法令用于降低那些颅内血管狭窄患者脑卒中的风险已经长达数十年，但是医生没有证据在这两种方法中进行选择。在这项叫做“华法令和阿司匹林治疗症状性颅内血管疾病的临床试验”的最新研究中，59个美国医疗中心的研究人员在总计569例患者中比较了每日使用1300毫克阿司匹林与华法令平均达1.8年期间的效果。所有患者颅内大动脉阻塞比例超过50％，在开始治疗的90天之内，经历了脑短暂性缺血发作或者非致残的脑卒中发作。

研究人员发现，不考虑患者所接受的治疗，大约22％患者继发缺血性脑卒中、脑出血或者由于其它血管相关疾病而死亡。但是，所有原因导致的大出血和死亡率在那些接受华法令治疗的患者(8.3%出血大出血；9.7%死亡)显著高于接受阿司匹林治疗的患者(3.2%出血；4.3%死亡)。根据这些结果，考虑到给予华法令患者的安全性，临床试验患者的入选比计划提前终止。

“这项试验的结果只与颅内血管狭窄的患者相关。”主持这项试验Emory大学的Marc I.Chimowitz博士解释说。因为与阿司匹林相比，华法令价格更贵治疗更复杂，如果不使用华法令预防与其相关的出血并发症，根据Chimowitz博士估计，每年将为美国节约200万美元。

研究人员指出：临床试验凸显示了这样一个事实，即颅内血管狭窄患者患脑卒中的风险特别高，需要更好的治疗方法。他们的研究结果发表在2005年3月31日的《新英格兰医学期刊》。
 
 
Aspirin vs Warfarin to Reduce Stroke Risk
 
Aspirin works as well as warfarin and has fewer side effects when used to reduce blood clotting in patients with partial blockage of arteries in the brain, according to a new study.

Both aspirin and warfarin have been used for decades to reduce the risk of stroke in patients with the condition known as intracranial stenosis, but doctors have had no evidence for choosing one therapy over the other. In the new study, called the Warfarin Aspirin Symptomatic Intracranial Disease (WASID) trial, investigators at 59 U.S. medical centers compared warfarin to 1,300 mg per day of aspirin in a total of 569 patients for an average of 1.8 years. All the patients had a greater-than-50% blockage of a major intracranial artery and had experienced a transient ischemic attack (TIA) or nondisabling stroke within 90 days of the start of the study.

Investigators found that about 22% of patients had a subsequent ischemic stroke, brain hemorrhage, or death from other blood-vessel-related causes, regardless of which therapy they received. However, the rates of major hemorrhage and death from all causes were significantly higher in those patients treated with warfarin (8.3% for major hemorrhage and 9.7% for death) than those treated with aspirin (3.2% for hemorrhage and 4.3% for death). Based on these results, enrollment in the trial was terminated earlier than planned because of concern for the safety of patients given warfarin.

“The results of this study are only relevant to people with intracranial stenosis,” explained Dr. Marc I. Chimowitz, of Emory University (Atlanta, GA, USA), who led the trial. Since warfarin is a more expensive and complicated therapy than aspirin, not using warfarin and preventing the bleeding complications associated with it would save more than U.S.$20 million a year in the United States alone, estimated Dr. Chimowitz.

The trial underscored the fact that patients with intracranial stenosis are at particularly high risk for stroke and that better therapies are needed, noted the investigators. Their results were published in the March 31, 2005, issue of The New England Journal of Medicine.