Aspirin unwarranted for primary prevention of cardiovascular disease

Richard Philip

While several guidelines recommend it, giving low-dose aspirin to prevent heart attacks and strokes in people who have not developed cardiovascular disease (CVD) should be stopped, says a recent review paper.

“Overall, we believe that the currently available evidence does not justify the routine use of low-dose aspirin for the primary prevention of CVD in apparently healthy individuals, including those with elevated blood pressure or diabetes; this is because of the potential risks and lack of effect on mortality,” said the review, which was published in the Drug and Therapeutics Bulletin – a monthly journal that provides independent evaluation and advice on treatments and disease management.

The review stated that while a number of guidelines published from 2005 to 2008 have encouraged aspirin-use for the primary prevention of CVD for a range of patients (for example, those aged 50 or above, type 2 diabetics or those with high blood pressure) there is no evidence to back such therapy.

A UK National Institute for Health and Clinical Excellence (NICE) guideline, which came out in 2008, recommended 75 mg of aspirin for patients with type 2 diabetes who are at least 50 years old if their blood pressure is lower than 145/90 mmHg and for younger patients with CV risk factors such as smoking and hypertension, noted the paper. [DTB 2009;47:122-125]

It also pointed out another recommendation from the Fourth Joint Taskforce of the European Society of Cardiology Guidelines published in 2007, which proposed 75 mg of aspirin per day for individuals without symptoms if their 10-year CVD death risk is more than 10 percent and blood pressure is controlled to the target of less than 140/90 mmHg.

Other recommendations for the use of aspirin in primary prevention of CVD came, for example, from the Joint British Societies’ 2005 guidelines and the Scottish Intercollegiate Guideline Network.

“Worldwide, many people take aspirin daily in the belief that doing so helps to prevent CVD. This approach is established for the secondary prevention of recurrent vascular events … there have been doubts about any benefits of aspirin in people with no history of CVD outweighing the risks,” said the article.

There is substantial research showing that aspirin may not be useful in the primary prevention of CVD. An example is a collaborative meta-analysis of six randomized controlled trials that appeared recently in the Lancet. While results from the analysis showed that all-cause mortality and death resulting from coronary heart disease (CHD) and stroke did not differ between the aspirin group and the control group, those who received aspirin had an increased chance of severe gastrointestinal or extracranial bleeding.

“In primary prevention without previous disease, aspirin is of uncertain net value as the reduction in occlusive events needs to be weighed against any increase in major bleeds,” the authors of the meta-analysis noted. They added that currently available trial findings do not appear to support the routine use of aspirin in all apparently healthy persons above a moderate level of CHD risk. [Lancet 2009;373:1849-60]

The paper called upon physicians to review all patients currently on low-dose aspirin for primary prevention, either as prescribed or over-the-counter treatment. It stated that the decision as to whether the patient should continue or stop the medication should be made only after physicians have fully apprised patients of the available evidence.

“We believe, therefore, that low dose aspirin prophylaxis should not be routinely used for primary prevention,” it concluded.

from : mims online