The balance of benefits and harms no longer favors aspirin for primary prevention

Référence

Moriarty F, Ebell MH. A comparison of contemporary versus older studies of aspirin for primary prevention. Fam Pract 2020;37(3):290-296.

Sommaire

Aspirin is recommended as primary prevention by the United States Preventive Services Task Force, primarily based on studies that recruited patients in the 1980s and 1990s. Those studies concluded that there was more benefit than risk: primarily a reduction in cardiovascular mortality, cardiovascular events, and colorectal cancer. Today, however, when we do a much better job of addressing other risk factors, such as tobacco use, hypertension, and hyperlipidemia, and when we routinely screen for colorectal cancer, does that benefit persist? The researchers (yes, I was one of them!) performed a meta-analysis of 4 large studies of aspirin for primary prevention that recruited patients after 2005, and compared them with individual patient data meta-analyses that recruited patients before 2000. In the newer studies, there was no longer any reduction in cancer death (relative risk [RR] 1.11; 95% CI 0.92 - 1.34) or cancer incidence (RR 1.06; 0.99 - 1.14). There was also no longer a significant reduction in nonfatal myocardial infarction (RR 0.90; 0.76 - 1.06) or cardiovascular mortality (RR 0.92; 0.81 - 1.06). Overall, for every 1200 persons who take aspirin instead of placebo for 5 years, there will be 4 fewer major cardiac events and 3 fewer ischemic strokes, but there will be 3 more intracranial hemorrhages and 8 more major bleeding events.