datasheet3_Pros and Cons of Aspirin for the Primary Prevention of Cardiovascular Events: A Secondary Study of Trial Sequential Analysis.pdf

Background and Aims: Aspirin leads to substantial benefits for the secondary prevention of cardiovascular disease (CVD). We aimed to cast more light on aspirin’s role for the primary prevention of CVD.
Methods: Databases were searched for clinical trials comparing aspirin vs. no aspirin use in this meta-analysis. Efficacy and safety profiles were rigorously investigated. Trial sequential analysis (TSA) was used to determine the robustness of the results.
Results: Fourteen studies with 163,840 participants were eligible (mean follow-up 6.2 y). Aspirin intake was found to be associated with 9, 13, and 12% reductions in the risk of cardiovascular events (CV events) (relative risk [RR]: 0.91, 95% confidence intervals [CI]: 0.87–0.96; risk difference (RD): 0.29%; absolute risk percentage (AR%): 7.61%; number needed to treat (NNT): 345), myocardial infarction (RR: 0.87, 95% CI: 0.77–0.97; RD: 0.21%; AR%: 11.11%; NNT: 488) and ischemic stroke (RR: 0.88, 95% CI: 0.80–0.96; RD: 0.21%; AR%: 16.14%; NNT: 476), respectively; aspirin intake was also associated with 40%, 30%, and 57% increases in the risk of major bleeding (RR: 1.40, 95% CI: 1.29–1.53; RD: 0.47%; AR%: 27.85; NNT: 214), intracranial bleeding (RR: 1.30, 95% CI: 1.11–1.52; RD: 0.10%; AR%: 22.99%; NNT: 1,000) and major gastrointestinal bleeding (RR: 1.57, 95% CI: 1.38–1.78; RD: 0.32%; AR%: 36.70%; NNT: 315), respectively. Further, populations with low doses of aspirin intake (≤100 mg), populations <65 y old or populations with body mass index (BMI) ≧ 25 experienced more advantages; high-risk (10-y cardiovascular risk ≧10%) and full diabetic individuals reported hardly clinical benefits.
Conclusion: Aspirin intake was associated with a reduced risk of CV events and an increased incidence of bleeding profiles in primary prevention. It is necessary to identify individual’s CVD risk using clear examinations or assessments before aspirin intake, and truly realize individualized prescription.

研究背景与研究目的：阿司匹林在心血管疾病（cardiovascular disease, CVD）的二级预防中具有显著临床获益，本研究旨在进一步阐明阿司匹林用于心血管疾病一级预防的作用。

研究方法：本项荟萃分析通过检索数据库，筛选对比阿司匹林与不使用阿司匹林的临床试验，严格评估其疗效与安全性特征，并采用试验序贯分析（trial sequential analysis, TSA）检验研究结果的稳健性。

研究结果：最终纳入符合标准的临床试验共14项，涉及受试者163840名，平均随访时长6.2年。结果显示，服用阿司匹林可分别使心血管事件（cardiovascular events, CV events）、心肌梗死及缺血性卒中的发病风险降低9%、13%和12%：相对风险（relative risk, RR）分别为0.91、0.87、0.88，95%置信区间（confidence interval, CI）分别为0.87~0.96、0.77~0.97、0.80~0.96；风险差（risk difference, RD）分别为0.29%、0.21%、0.21%；绝对风险百分比（absolute risk percentage, AR%）分别为7.61%、11.11%、16.14%；需治疗人数（number needed to treat, NNT）分别为345、488、476。同时，服用阿司匹林可分别使大出血、颅内出血及主要胃肠道出血的发病风险增加40%、30%和57%：大出血的RR分别为1.40、1.30、1.57，95%CI分别为1.29~1.53、1.11~1.52、1.38~1.78；RD分别为0.47%、0.10%、0.32%；AR%分别为27.85、22.99、36.70；NNT分别为214、1000、315。亚组分析显示，服用低剂量阿司匹林（≤100mg）、年龄<65岁人群或体重指数（body mass index, BMI）≥25的受试者可获得更多临床获益；而10年心血管风险≥10%的高风险人群及糖尿病患者几乎未获得临床获益。

研究结论：在心血管疾病一级预防中，服用阿司匹林可降低心血管事件的发病风险，但同时会增加出血事件的发生率。因此，在服用阿司匹林前，需通过明确的检查或评估手段明确个体的心血管疾病风险，真正实现个体化给药方案。