Aspirin not as effective for primary prevention?

Meta-Analysis Questions Use of Aspirin in Primary Prevention CME

News Author: Sue Hughes
CME Author: Désirée Lie, MD, MSEd

June 9, 2009 — The authors of a new meta-analysis of aspirin use in primary prevention say their results "do not seem to justify general guidelines advocating the routine use of aspirin in all healthy individuals above a moderate level of risk for coronary heart disease. "

The meta-analysis, published in the May 30, 2009 issue of the Lancet, was conducted by the Antithrombotic Trialists' (ATT) Collaboration, led by Dr Colin Baigent (Clinical Trial Service Unit, Oxford University, UK).

Baigent commented to heartwire : "The present data that we have reported here have not been previously available. The current guidelines are based on previous meta-analyses, which have limitations. We have shown for the first time that the very same people at higher risk of heart disease are also at higher bleeding risk with aspirin, which is a very important piece of information and should influence the way in which aspirin is used."

He added: "Medicine has moved on in recent years, and we now know that we can safely reduce risk of heart disease by lowering cholesterol and blood pressure, and the drugs used to lower these risk factors are probably safer than aspirin. A person wanting to lower their risk might well consider taking a statin or an antihypertensive first and only after that add in a less safe drug like aspirin."

Baigent pointed out that the present guidelines, recommending aspirin for primary prevention in all people above a certain risk, are not supported by this new meta-analysis. "It is not for us to recommend changes in guidelines, but I would think the guidelines committees would now want to review their recommendations in light of these new findings," he said. "I'm not saying you should never use aspirin for primary prevention, and certain individuals may wish to still take it after discussing the risks and benefits with their doctor, which I think is fine. But our data suggest there is not good evidence of substantial benefit that outweighs risk enough to justify a public policy recommending routine use above a moderate CHD risk in primary prevention."

He added that this advice does not affect recommendations for secondary prevention, where the absolute benefit of aspirin is much greater and vastly outweighs the risk of bleeding.

source: http://cme.medscape.com/viewarticle/704102?sssdmh=dm1.483760&src=nldne