Background

Among asymptomatic patients with severe carotid artery stenosis but no recent stroke or transient cerebral ischaemia, either carotid artery stenting (CAS) or carotid endarterectomy (CEA) can restore patency and reduce long-term stroke risks. However, from recent national registry data, each option causes about 1% procedural risk of disabling stroke or death. Comparison of their long-term protective effects requires large-scale randomised evidence.

Methods

ACST-2 is an international multicentre randomised trial of CAS versus CEA among asymptomatic patients with severe stenosis thought to require intervention, interpreted with all other relevant trials. Patients were eligible if they had severe unilateral or bilateral carotid artery stenosis and both doctor and patient agreed that a carotid procedure should be undertaken, but they were substantially uncertain which one to choose. Patients were randomly allocated to CAS or CEA and followed up at 1 month and then annually, for a mean 5 years. Procedural events were those within 30 days of the intervention. Intention-to-treat analyses are provided. Analyses including procedural hazards use tabular methods. Analyses and meta-analyses of non-procedural strokes use Kaplan-Meier and log-rank methods. The trial is registered with the ISRCTN registry, ISRCTN21144362.

Findings

Between Jan 15, 2008, and Dec 31, 2020, 3625 patients in 130 centres were randomly allocated, 1811 to CAS and 1814 to CEA, with good compliance, good medical therapy and a mean 5 years of follow-up. Overall, 1% had disabling stroke or death procedurally (15 allocated to CAS and 18 to CEA) and 2% had non-disabling procedural stroke (48 allocated to CAS and 29 to CEA). Kaplan-Meier estimates of 5-year non-procedural stroke were 2·5% in each group for fatal or disabling stroke, and 5·3% with CAS versus 4·5% with CEA for any stroke (rate ratio [RR] 1·16, 95% CI 0·86–1·57; p=0·33). Combining RRs for any non-procedural stroke in all CAS versus CEA trials, the RR was similar in symptomatic and asymptomatic patients (overall RR 1·11, 95% CI 0·91–1·32; p=0·21).

Interpretation

Serious complications are similarly uncommon after competent CAS and CEA, and the long-term effects of these two carotid artery procedures on fatal or disabling stroke are comparable.

Funding

UK Medical Research Council and Health Technology Assessment Programme.

中文翻译：

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第二次无症状颈动脉手术试验 (ACST-2)：颈动脉支架置入术与颈动脉内膜切除术的随机比较

背景

在有严重颈动脉狭窄但没有近期卒中或短暂性脑缺血的无症状患者中，颈动脉支架置入术 (CAS) 或颈动脉内膜切除术 (CEA) 可以恢复通畅并降低长期卒中风险。然而，从最近的国家登记数据来看，每种选择都会导致约 1% 的致残性中风或死亡的手术风险。比较它们的长期保护作用需要大规模的随机证据。

方法

ACST-2 是一项国际多中心随机试验，在被认为需要干预的严重狭窄无症状患者中进行 CAS 与 CEA 对比，并与所有其他相关试验一起解释。如果患者有严重的单侧或双侧颈动脉狭窄，并且医生和患者都同意应该进行颈动脉手术，则他们符合条件，但他们基本上不确定选择哪一种。患者被随机分配到 CAS 或 CEA，并在 1 个月后进行随访，然后每年进行一次，平均 5 年。程序性事件是干预后 30 天内的事件。提供了意向治疗分析。包括程序危害在内的分析使用表格方法。非程序性中风的分析和荟萃分析使用 Kaplan-Meier 和对数秩方法。该试验已在 ISRCTN 登记处注册，

发现

2008 年 1 月 15 日至 2020 年 12 月 31 日期间，130 个中心的 3625 名患者被随机分配，其中 1811 名接受 CAS，1814 名接受 CEA，依从性好，药物治疗良好，平均随访 5 年。总体而言，1% 的患者在程序上发生致残性卒中或死亡（15 人分配到 CAS，18 人分配到 CEA），2% 发生非致残性程序性卒中（48 人分配到 CAS，29 人分配到 CEA）。Kaplan-Meier 估计每组 5 年非手术性卒中的致命性或致残性卒中为 2·5%，CAS 为 5·3%，而 CEA 为 4·5%（发生率比 [RR] 1 ·16, 95% CI 0·86–1·57；p=0·33)。结合所有 CAS 与 CEA 试验中任何非手术性卒中的 RR，有症状和无症状患者的 RR 相似（总体 RR 1·11，95% CI 0·91-1·32；p=0·21）。

解释

接受 CAS 和 CEA 后，严重并发症同样不常见，这两种颈动脉手术对致命或致残中风的长期影响相当。

资金

英国医学研究委员会和卫生技术评估计划。