老年人應該堅持服用小劑量阿司匹林預防心血管疾病嗎？

老年人應該每天服用小劑量阿斯匹林以降低心血管病風險，這好像已經成為大家的共識。然而今天讀到最新發表在最權威的醫學雜誌「新英格蘭醫學」上的一片文章，讓我想建議父母關於要不要吃阿司匹林最好還是要三思而行。因為根據作者的研究，不僅阿斯匹林的預防效果有限，更重要的是長期服用加大了腦出血，胃腸道出血的危險。所以對於只有高血壓而沒有過冠心病腦梗塞發作的老年人，在這個問題上一定要慎重。

這個研究招募了近兩萬居住在澳大利亞和美國的相對健康的老年人。他們被隨機分為兩組，服用阿司匹林組和服用安慰劑對照組。總體上講，服用阿司匹林組患心血管病的比例略低一些，每1000人-年中是10.7次，對照組是11.3。服用阿司匹林增加了出血的機會，包括腦出血和胃腸道出血。雖然有嚴重出血的人沒有得心血管病的人那麼多，但是服用阿斯匹林的人和對照組的人在出血機率方面是有著顯著差異的。在阿司匹林組，比例是每1000人-年中8.6次，對照組是6.2次。更具體的患病種類和人數可參見後面論文提供的附表。

此論文摘要的譯文如下：

題目：阿斯匹林對健康老年人心血管事件和出血的影響

摘要：

背景介紹：服用阿司匹林是用於心血管事件二級預防的成熟療法。然而，其在心血管疾病一級預防中的作用尚不清楚，特別是在風險增加的老年人中。

* （解釋：冠心病的預防分為一級預防和二級預防，一級預防指減少或控制冠心病的危險因素，降低發病率；二級預防是對已患有冠心病的患者採用藥物或非藥物的措施以預防複發或防止病情加重。）

方法：從2010年到2014年，我們招募了在澳大利亞和美國社區居住的年齡大於70歲的沒有心血管疾病，老年痴呆症或殘疾的男性和女性（如是美國黑人和西班牙裔人，則年齡≥65歲即可）。參與者被隨機分配接受100毫克腸溶阿司匹林或安慰劑。主要終點指標是死亡，痴呆或持續性身體殘疾的綜合癥狀，其結果報導於該期刊的另一篇文章。次要終點指標包括主要出血和心血管疾病（定義為致死性冠心病，非致死性心肌梗死，致死性或非致死性腦中風或需住院治療的心力衰竭）。

結果：共19114人參與試驗。其中9525人服用阿司匹林，9589人接受安慰劑。經過中位數為4.7年的隨訪，心血管事件發病率為阿司匹林組1000人中10.7次，安慰劑組1000人中11.3次（阿司匹林風險機率0.95；95%可信區間0.83 to 1.08）。主要出血事件發病率分別為1000人中8.6次，和1000人中6.2次（風險機率為1.38；95%可信區間1.18to 1.62，兩者有顯著區別）。

結論：服用低劑量阿斯匹林作為老年人一級預防的策略明顯增加了主要出血的風險，但並沒有比對照組有明顯降低心血管疾病的風險。

Effect of Aspirin on Cardiovascular Events and Bleeding in the Healthy Elderly

J.J.McNeil and others

The New England Journal of Medicine

Published on September 16, 2018

BACKGROUND: Aspirin is a well-established therapy for the secondary prevention of cardiovascular events. However, its role in the primary prevention of cardiovascular disease is unclear, especially in older persons, who have an increased risk.

METHODS: From 2010 through 2014, we enrolled community-dwelling men and women in Australia and the United States who were 70 years of age or older (or ≥65 years of age among blacks and Hispanics in the United States) and did not have cardiovascular disease, dementia, or disability. Participants were randomly assigned to receive 100 mg of enteric-coated aspirin or placebo. The primary end point was a composite of death, dementia, or persistent physical disability; results for this end point are reported in another article in the Journal. Secondary end points included major hemorrhage and cardiovascular disease (defined as fatal coronary heart disease, nonfatal myocardial infarction, fatal or nonfatal stroke, or hospitalization for heart failure).

RESULTS: Of the 19,114 persons who were enrolled in the trial, 9525 were assigned to receive aspirin and 9589 to receive placebo. After a median of 4.7 years of follow-up, the rate of cardiovascular disease was 10.7 events per 1000 person-years in the aspirin group and 11.3 events per 1000 person-years in the placebo group (hazard ratio, 0.95; 95% confidence interval [CI],). The rate of major hemorrhage was 8.6 events per 1000 person-years and 6.2 events per 1000 person-years, respectively (hazard ratio, 1.38; 95% CI, 1.18 to 1.62; P<0.001).

CONCLUSIONS: The use of low-dose aspirin as a primary prevention strategy in older adults resulted in a significantly higher risk of major hemorrhage and did not result in a significantly lower risk of cardiovascular disease than placebo.

文章主要附表及翻譯如下