Selak Vanessa, Jackson Rod, Poppe Katrina, Kerr Andrew, Wells Sue
Senior Lecturer, Epidemiology & Biostatistics, University of Auckland, Auckland.
Professor, Epidemiology & Biostatistics, University of Auckland, Auckland.
N Z Med J. 2018 Oct 26;131(1484):19-25.
The 2018 New Zealand Consensus Statement on cardiovascular disease (CVD) risk assessment and management recommends the use of aspirin in people aged less than 70 years with a five-year CVD risk >15% but without prior CVD. We determined whether the estimated number of CVD events avoided by taking aspirin is likely to exceed the number of additional major bleeds caused by aspirin in this patient population.
Major bleeding rates were obtained from the PREDICT primary care study, a large New Zealand cohort of people eligible for CVD risk assessment, after excluding those with no other indications for (eg, established CVD) or contraindications/cautions (eg, prior major bleed) to aspirin use. We modelled the benefits (CVD events avoided) and harms (additional major bleeds) of aspirin for primary prevention of CVD over five years using hypothetical populations aged 40 to 79 years, stratified by sex, age-group and estimated five-year CVD risk. Two clinical scenarios were modelled, according to whether or not optimisation of lipid- and blood pressure-lowering therapy was required prior to aspirin initiation.
In both clinical scenarios the number of CVD events prevented by aspirin over five years was estimated to be, on average, more than the number of bleeds caused by aspirin among people aged less than 70 years with estimated five-year CVD risk of >15%. However, the magnitude of the net benefit of aspirin was modest among people aged 60-69 years, particularly if lipid- and blood pressure-lowering therapy had not already been optimised.
The benefits of aspirin are likely to exceed the risk of major bleeds among people in whom aspirin is recommended for the primary prevention of CVD. A more cautious approach to the use of aspirin is appropriate for people aged 60-69 years who are likely to have a smaller net benefit from aspirin, particularly those in whom lipid- and blood pressure-lowering therapy has not already been optimised or who have other bleeding risk factors, such as diabetes or smoking. More specific recommendations will be possible when bleeding risk equations are developed to complement the recently developed New Zealand CVD risk equations.
《2018年新西兰心血管疾病（CVD）风险评估与管理共识声明》建议，对于年龄小于70岁、5年CVD风险>15%但无既往CVD的人群使用阿司匹林。我们确定了在该患者群体中，服用阿司匹林避免的CVD事件估计数量是否可能超过阿司匹林导致的额外严重出血数量。
主要出血率来自PREDICT初级保健研究，这是一个符合CVD风险评估条件的新西兰大型队列，排除了那些无其他阿司匹林使用指征（如已确诊的CVD）或禁忌证/注意事项（如既往严重出血）的人群。我们使用年龄在40至79岁之间的假设人群，按性别、年龄组和估计的5年CVD风险分层，对阿司匹林在5年内预防CVD一级预防的益处（避免的CVD事件）和危害（额外的严重出血）进行建模。根据在开始使用阿司匹林之前是否需要优化降脂和降压治疗，对两种临床情况进行了建模。
在两种临床情况下，对于年龄小于70岁、估计5年CVD风险>15%的人群，估计阿司匹林在5年内预防的CVD事件数量平均超过阿司匹林导致的出血数量。然而，在60 - 69岁人群中，阿司匹林净益处的幅度较小，特别是如果降脂和降压治疗尚未优化。
对于推荐使用阿司匹林进行CVD一级预防的人群，阿司匹林的益处可能超过严重出血风险。对于60 - 69岁人群，使用阿司匹林时采用更谨慎的方法是合适的，他们可能从阿司匹林中获得的净益处较小，特别是那些降脂和降压治疗尚未优化或有其他出血风险因素（如糖尿病或吸烟）的人群。当开发出血风险方程以补充最近开发的新西兰CVD风险方程时，将有可能提出更具体的建议。
