中国神经内科网
当前位置: 主页 > 资讯中心 > 临床进展 >

阿司匹林对房颤患者的卒中预防无效且不安全

时间:2011-10-20 13:17来源:卒中网 作者:admin 点击:

 

2011年10月《Thrombosis and Haemostasis》杂志上发表一项丹麦新的研究证实,阿司匹林对房颤患者的卒中预防无效且不安全(摘自www.theheart.org)。
阿司匹林对房颤患者卒中的预防无效且不安全  
该研究的第二作者、英国伯明翰大学的Gregory Lip教授指出,此研究是迄今为止已发表的有关阿司匹林和口服抗凝药物用于房颤患者卒中预防、规模最大的真实世界的队列研究。该研究明确证实了,阿司匹林对任何卒中风险的房颤患者都无临床净获益,既不安全也无效。
至今只有SPAF-1研究证实了阿司匹林可降低房颤患者的卒中风险,而随后的众多研究表明阿司匹林可能并不能有效预防房颤患者的卒中风险,可能也并不比华法林安全。尽管如此,临床医生还是选择了阿司匹林。
日本的一项研究曾证实,阿司匹林对低风险的房颤患者无益。据此,2010年ESC更新指南,不建议阿司匹林用于任何房颤患者的卒中预防。Gregory Lip教授说,该丹麦研究为ESC指南的最新推荐提供了进一步证据支持。
华法林对除外低风险的房颤患者都有效
该研究的另一重要发现是,华法林对所有房颤患者都有效,但除外卒中风险极低的患者(CHA2DS2-VASc评分为0)。Gregory Lip教授说,在卒中风险极低的患者,华法林导致的出血风险大于临床获益。
出血风险越大的患者,华法林的临床获益越大
丹麦这项新研究的另一个发现是,出血风险最高的患者,华法林的临床获益也最大。Gregory Lip教授解释说,因为这类患者通常也有极高的卒中风险,华法林降低卒中风险的绝对获益很容易高于出血风险。但是,很多医生担心华法林的出血风险,很可能用阿司匹林代替,殊不知,这类患者最适合华法林(或新型口服抗凝剂中的一种),而不是阿司匹林。而且,对单纯房颤患者,一种口服抗凝药是最佳选择,即使是伴有稳定型心绞痛的房颤患者,也没有必要在华法林的基础上再加服阿司匹林。
Gregory Lip教授补充说,随着对华法林的应用越来越好,以及使用更加方便的新一代口服抗凝药的诞生,我们确信我们可以为合并一种或一种以上卒中危险因素的房颤患者提供有效的卒中预防。
 
Aspirin should not be used for stroke prevention in AF patients
London, UK - More evidence that aspirin is neither safe nor effective for the prevention of stroke in AF patients has come from a new Danish registry study.
The study, published in the October 2011 issue of Thrombosis and Haemostasis, was conducted by a group led by Dr Jonas Bjerring Olesen (Copenhagen University Hospital Gentofte, Hellerup, Denmark).
Second author Dr Gregory Lip (University of Birmingham, UK) commented to heartwire: "Our study is the largest real-world cohort study ever published looking at the use of aspirin and oral anticoagulation in AF patients, and it clearly shows that the net clinical benefit for aspirin is not positive at any level of stroke risk. It is neither safe nor effective."
He explained that there is a perception that aspirin is a safer alternative to oral anticoagulation for stroke prevention in AF patients, but "now we know that this simply is not the case."
As background, Lip noted that a meta-analysis of randomized trials of aspirin in AF suggested a 19% reduction in stroke, with confidence limits that crossed zero, and many of the trials included less than 10% of patients screened. The suggested benefit in this meta-analysis was driven by only one positive trial (SPAF-1). "Since then, increasing data have suggested that aspirin may not be effective at preventing stroke in this situation and may not be any safer than warfarin either. Despite this, doctors have embraced aspirin," Lip said.
He said the results of the new Danish study were in line with the latest European Society of Cardiology (ESC) guidelines, which were updated last year. These advised against using aspirin for stroke prevention in any AF patients after a Japanese study showed no benefit in low-risk patients. "The ESC updated the guidelines based on this study. Now our study has provided more real-world data in support of this recommendation."For the Danish study, the researchers estimated the risk of thromboembolism and bleeding in 146 000 AF patients by linking data from the Danish National Patient Registry (which documents all patient hospitalizations), the Danish Registry of Medicinal Product Statistics (which records all prescription medicines prescribed to individual patients), and the National Causes of Death Registry.
 
Warfarin effective for all but very lowest risk
Another important finding was that warfarin was associated with a net clinical benefit in all AF patients except those at the very lowest risk of stroke (CHA2DS2-VASc score of 0). "It is only in these very low-risk patients that the bleeding risk of warfarin outweighs the benefit," Lip stated.
He added that these data did not apply to the new generation of oral anticoagulants, as they are only now reaching the market and so were not included in this study. "It is possible that the new drugs may be beneficial in the very lowest-risk patients, but we don't have data on this yet. All we can say for now is that warfarin is not beneficial for this one group, but it is beneficial for all other AF patients."
Lip explained that the CHA2DS2-VASc score is more inclusive of stroke risk factors than the CHADS2 score, and the two scores tend to be complementary. "If the CHADS2 score is already known to be 2, for example, there is no need for a CHA2DS2-VASc score, because we know that patient needs to be on anticoagulation. But if the CHADS2 score is 0, patients could still have some stroke risk factors, and then the CHA2DS2-VASc score should be used as well. A CHA2DS2-VASc score of 0 signifies a very low risk indeed of thromboembolism—about 0.78 per 100 person-years."
Most benefit of warfarin in those at highest bleeding risk
Another finding of note in the Danish study was that the net clinical benefit of warfarin was highest in those patients with the highest bleeding risk. Lip explained that this was because these patients usually have the highest stroke risk too, and the absolute benefit of warfarin on reducing stroke risk easily outweighs the bleeding hazard. "These are the very patients that many doctors are wary of giving warfarin to, and they may be using aspirin instead, but these are actually the patients who need warfarin (or one of the new oral anticoagulants) the most. Aspirin is not the answer for these patients.
"I can't say that no AF patient should be taking aspirin, because many such patients may have other indications such as having had a stent, but for patients with AF alone, an oral anticoagulant is best, and even in AF patients with stable vascular disease there is no requirement to add aspirin on top of warfarin," he said.
But he added that this study suggests that oral anticoagulants are vastly underused for stroke prevention in AF. "We are now getting better at managing warfarin, and we have a new generation of easier-to-use oral anticoagulants, so we must make sure that we are offering effective stroke prevention to all AF patients with one or more stroke risk factors," Lip urged.
顶一下
(15)
100%
踩一下
(0)
0%
------分隔线----------------------------
发表评论
请自觉遵守互联网相关的政策法规,严禁发布色情、暴力、反动的言论。
评价:
表情:
用户名: 验证码:点击我更换图片
栏目列表
精彩内容
推荐内容