Rothwell P M, Gutnikov S A, Warlow C P
Stroke Prevention Research Unit, University Department of Clinical Neurology, Radcliffe Infirmary, Oxford, UK.
Stroke. 2003 Feb;34(2):514-23. doi: 10.1161/01.str.0000054671.71777.c7.
The European Carotid Surgery Trial (ECST) and North American Symptomatic Carotid Endarterectomy Trial (NASCET) have shown that endarterectomy reduces the risk of stroke in certain patients with recently symptomatic carotid stenosis. However, they differed in the degree of stenosis above which surgery was reported to be effective. This disparity has led to inconsistent clinical recommendations but may have been due to differences between the trials in the methods of measurement of carotid stenosis and definitions of outcome events.
To allow direct comparison of analyses from ECST and NASCET, we remeasured the prerandomization ECST carotid angiograms and redefined the outcome events the same way as in NASCET.
We randomized 3018 patients and followed them up for a mean of 73 months. Surgery reduced the 5-year risk of any stroke or surgical death by 5.7% (95% CI, 0 to 11.6) in patients with 50% to 69% stenosis (n=646, P=0.05) and by 21.2% (95% CI, 12.9 to 29.4) in patients with 70% to 99% stenosis without "near occlusion" (n=429, P<0.0001). These benefits were maintained at the 10-year follow-up. However, surgery was of no benefit in patients (n=125) with near occlusion. The effect of surgery in this group was highly significantly different from that in patients with 70% to 99% stenosis without near occlusion (P=0.002). Surgery was harmful in patients with <30% stenosis (n=1321, P=0.007) and of no benefit in patients with 30% to 49% stenosis (n=478, P=0.6).
Results of the ECST and NASCET were consistent when analyzed in the same way. In ECST, surgery was highly beneficial for 70% to 99% stenosis and moderately beneficial for 50% to 69% stenosis. However, contrary to clinical recommendations and current practice, surgery was of little benefit in patients with carotid near occlusion.
欧洲颈动脉外科试验（ECST）和北美症状性颈动脉内膜切除术试验（NASCET）表明，内膜切除术可降低近期有症状的某些颈动脉狭窄患者的中风风险。然而，它们在报告手术有效的狭窄程度方面存在差异。这种差异导致了临床建议的不一致，但可能是由于两个试验在颈动脉狭窄测量方法和结局事件定义上存在差异。
为了直接比较ECST和NASCET的分析结果，我们重新测量了随机分组前的ECST颈动脉血管造影，并按照与NASCET相同的方式重新定义结局事件。
我们将3018例患者随机分组，并对他们进行了平均73个月的随访。对于狭窄程度为50%至69%的患者（n = 646，P = 0.05），手术使任何中风或手术死亡的5年风险降低了5.7%（95% CI，0至11.6）；对于狭窄程度为70%至99%且无“接近闭塞”的患者（n = 429，P < 0.0001），手术使该风险降低了21.2%（95% CI，12.9至29.4）。这些益处维持到了10年随访时。然而，对于接近闭塞的患者（n = 125），手术并无益处。该组手术效果与狭窄程度为70%至99%且无接近闭塞的患者相比差异极为显著（P = 0.002）。对于狭窄程度<30%的患者（n = 1321，P = 0.007），手术有害；对于狭窄程度为30%至49%的患者（n = 478，P = 0.6），手术无益处。
以相同方式分析时，ECST和NASCET的结果是一致的。在ECST中，手术对于70%至99%的狭窄高度有益，对于50%至69%的狭窄中度有益。然而，与临床建议和当前实践相反，手术对于颈动脉接近闭塞的患者益处不大。
