Background

Optimal antiplatelet monotherapy during the chronic maintenance period in patients who undergo coronary stenting is unknown. We aimed to compare head to head the efficacy and safety of aspirin and clopidogrel monotherapy in this population.

Methods

We did an investigator-initiated, prospective, randomised, open-label, multicentre trial at 37 study sites in South Korea. We enrolled patients aged at least 20 years who maintained dual antiplatelet therapy without clinical events for 6–18 months after percutaneous coronary intervention with drug-eluting stents (DES). We excluded patients with any ischaemic and major bleeding complications. Patients were randomly assigned (1:1) to receive a monotherapy agent of clopidogrel 75 mg once daily or aspirin 100 mg once daily for 24 months. The primary endpoint was a composite of all-cause death, non-fatal myocardial infarction, stroke, readmission due to acute coronary syndrome, and Bleeding Academic Research Consortium (BARC) bleeding type 3 or greater, in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT02044250.

Findings

Between March 26, 2014, and May 29, 2018, we enrolled 5530 patients. 5438 (98·3%) patients were randomly assigned to either the clopidogrel group (2710 [49·8%]) or to the aspirin group (2728 [50·2%]). Ascertainment of the primary endpoint was completed in 5338 (98·2%) patients. During 24-month follow-up, the primary outcome occurred in 152 (5·7%) patients in the clopidogrel group and 207 (7·7%) in the aspirin group (hazard ratio 0·73 [95% CI 0·59–0·90]; p=0·0035).

Interpretation

Clopidogrel monotherapy, compared with aspirin monotherapy during the chronic maintenance period after percutaneous coronary intervention with DES significantly reduced the risk of the composite of all-cause death, non-fatal myocardial infarction, stroke, readmission due to acute coronary syndrome, and BARC bleeding type 3 or greater. In patients requiring indefinite antiplatelet monotherapy after percutaneous coronary intervention, clopidogrel monotherapy was superior to aspirin monotherapy in preventing future adverse clinical events.

Funding

ChongKunDang, SamJin, HanMi, DaeWoong, and the South Korea Ministry of Health and Welfare.

中文翻译：

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经皮冠状动脉介入治疗 (HOST-EXAM) 后阿司匹林与氯吡格雷长期维持单药治疗：一项由研究者发起的前瞻性、随机、开放标签、多中心试验

背景

在接受冠状动脉支架置入术的患者的长期维持期内，最佳抗血小板单药治疗尚不清楚。我们旨在比较阿司匹林和氯吡格雷单药治疗在该人群中的疗效和安全性。

方法

我们在韩国的 37 个研究地点进行了一项由研究者发起的前瞻性、随机、开放标签、多中心试验。我们招募了年龄至少为 20 岁的患者，这些患者在使用药物洗脱支架 (DES) 进行经皮冠状动脉介入治疗后 6-18 个月内维持双重抗血小板治疗且未发生临床事件。我们排除了有任何缺血性和大出血并发症的患者。患者被随机分配 (1:1) 接受氯吡格雷 75 mg 每天一次或阿司匹林 100 mg 每天一次的单药治疗 24 个月。主要终点是意向治疗人群中的全因死亡、非致命性心肌梗死、中风、急性冠状动脉综合征再入院和出血学术研究联盟 (BARC) 3 型或更大出血的复合终点。该试验已在 ClinicalTrials.gov 注册，NCT02044250。

发现

在 2014 年 3 月 26 日至 2018 年 5 月 29 日期间，我们招募了 5530 名患者。5438 (98·3%) 名患者被随机分配到氯吡格雷组 (2710 [49·8%]) 或阿司匹林组 (2728 [50·2%])。5338 名 (98·2%) 患者完成了主要终点的确定。在 24 个月的随访期间，主要结局发生在氯吡格雷组 152 名（5·7%）患者和阿司匹林组 207 名（7·7%）患者（风险比 0·73 [95% CI 0·59 –0·90]；p=0·0035)。

解释

氯吡格雷单药治疗与阿司匹林单药治疗相比，在经皮冠状动脉介入治疗后的慢性维持期内显着降低了全因死亡、非致死性心肌梗死、卒中、急性冠状动脉综合征再入院和 BARC 出血类型的复合风险3 或更大。在经皮冠状动脉介入治疗后需要无限期抗血小板单药治疗的患者中，氯吡格雷单药治疗在预防未来不良临床事件方面优于阿司匹林单药治疗。

资金

ChongKunDang、SamJin、HanMi、DaeWoong 和韩国保健福祉部。