背景:低剂量直接口服抗凝药(DOACs)辅助抗血小板治疗,被称为双途径抑制(DPI),已在心血管疾病(CVD)患者中进行了预防缺血事件的测试。我们进行了系统评价和荟萃分析,以确定低剂量DOAC的总体安全性和有效性与安慰剂在抗血小板治疗的背景下。
方法:所有随机对照试验(RCT)比较低剂量DOAC(定义为低于批准用于预防中风的最低剂量)与在至少50%的人群中接受单一或双重抗血小板治疗的CVD患者中服用安慰剂,并随访至少6个月,包括在内。使用具有95%置信区间(CIs)的发生率比(IRRs)来克服试验中不同的随访持续时间。主要疗效终点为主要不良心血管事件(MACE)和主要安全性终点为大出血。对不同的DOAC剂量方案进行预先指定的亚组分析。
结果:共纳入来自7个RCTs的55,782例患者。与安慰剂相比,低剂量DOAC与MACE(IRR0.85,95%CI0.78-0.91)和心肌梗死(IRR0.86,95%CI0.78-0.95)的显着降低以及主要(IRR2.05,95%CI1.50-2.80)或所有出血(IRR1.82,95%CI1.49-2.22)的显着增加。CV死亡(内部收益率0.90,95%CI0.79-1.03),颅内出血(IRR1.18,95%CI0.71-1.96)和致命性出血(IRR1.13,95%CI0.76-1.69)在两种策略之间没有显著差异.所有原因死亡(IRR0.90,95%CI0.80-1.01)和中风(IRR0.73,95%CI0.53-1.01)的非显着降低有利于低剂量DOAC。Meta回归分析显示DAPT使用百分比与大出血风险增加之间存在显著交互作用(p=0.04),颅内出血(p=0.035)和卒中(p=0.0003)。极低剂量DOAC的亚组分析,定义为≤中风预防最低批准剂量的1/3(即,与其他低剂量DOAC方案相比,利伐沙班2.5mg,每日两次)似乎可以减轻出血风险,而无需权衡疗效。
结论:在CVD患者中,低剂量DOAC方案与安慰剂,在抗血小板治疗的背景下,以增加大出血和所有出血为代价有效减少缺血事件,但是没有显著增加颅内或致命的出血,而心血管疾病和总死亡率的降低没有统计学意义。使用极低剂量DOAC(即利伐沙班每天两次2.5mg)的DPI显得特别有利,特别是当与单一抗血小板药物联合使用时,在高缺血和低出血风险的患者中使用。
背景:本研究在PROSPERO(CRD42021232744)中注册。
BACKGROUND: Low-dose direct oral anticoagulants (DOACs) in adjunct to antiplatelet therapy, known as dual pathway inhibition (DPI), have been tested to prevent ischaemic events in patients with cardiovascular disease (CVD). We conducted a systematic review and meta-analysis to determine the overall safety and efficacy of low-dose DOACs vs. placebo on a background of antiplatelet therapy.
METHODS: All randomized controlled trials (RCTs) comparing low-dose DOAC (defined as a dosage below the lowest approved for stroke prevention) vs. placebo among patients with CVD receiving single or dual antiplatelet therapy in at least 50% of the population and followed for at least 6 months, were included. Incidence rate ratios (IRRs) with 95% confidence intervals (CIs) were used to overcome different follow-up durations across trials. The primary efficacy endpoint was major adverse cardiovascular events (MACE) and the primary safety endpoint major bleeding. A pre-specified subgroup analysis was performed for different DOAC-dose regimens.
RESULTS: A total of 55,782 patients from 7 RCTs were included. Low-dose DOACs vs placebo were associated with significant reductions in MACE (IRR 0.85, 95% CI 0.78-0.91) and myocardial infarction (IRR 0.86, 95% CI 0.78-0.95) and significant increases of major (IRR 2.05, 95% CI 1.50-2.80) or all bleeding (IRR 1.82, 95% CI 1.49-2.22). CV death (IRR 0.90, 95% CI 0.79-1.03), intracranial (IRR 1.18, 95% CI 0.71-1.96) and fatal bleeding (IRR 1.13, 95% CI 0.76-1.69) did not differ significantly between strategies. Non-significant reductions of all-cause death (IRR 0.90, 95% CI 0.80-1.01) and stroke (IRR 0.73, 95% CI 0.53-1.01) favoured low-dose DOACs. Meta-regression analyses showed a significant interaction between percentage of DAPT use and increased risk of major bleeding (p = 0.04), intracranial Haemorrhage (p = 0.035) and stroke (p = 0.0003). Subgroup analysis of very low-dose DOAC, defined as ≤ 1/3 of the lowest approved dose for stroke prevention (i.e., rivaroxaban 2.5 mg twice daily) seems to mitigate the risk of bleeding without any trade-off in efficacy compared to other low-dose DOAC regimens.
CONCLUSIONS: In patients with CVD, a low-dose DOAC regimen vs. placebo, on a background of antiplatelet therapy, is effective in reducing ischaemic events at the expense of increased major and all bleeding, but without significantly increasing intracranial or fatal bleeds, while the reduction of cardiovascular and total mortality is not statistically significant. A DPI with very low-dose DOAC (i.e. rivaroxaban 2.5 mg twice daily) appears particularly advantageous, especially when combined with a single antiplatelet agent and used among patients at high ischaemic and low bleeding risk.
BACKGROUND: This study is registered in PROSPERO (CRD42021232744).