Taking a small daily dose of aspirin to prevent cardiovascular disease is of little use to healthy women. This is the conclusion of researchers from the University Medical Center (UMC) Utrecht. They recently published their results in the European Heart Journal.
Aspirin is a blood thinner and can prevent the development of small blood clots in blood vessels and strokes. But a daily dose of aspirin can also cause bruising and blood in the urine and sometimes even bleeding in the stomach or brain. So when do the advantages outweigh the disadvantages? In people who have already had a stroke, aspirin does in general have a beneficial effect. But what about healthy people? This is a discussion that has been going on between doctors for a long time.
Together with researchers from the Harvard Medical School, Dr. Frank Visseren, a specialist in internal medicine, doctor and researcher Jannick Dorresteijn and colleagues from UMC Utrecht analyzed data from the Women’s Health Study. In this study, nearly 40,000 women aged 45 years or older took either aspirin or a placebo for a period of ten years. Aspirin reduces the relative risk of cardiovascular disease for the average woman by nine percent. But the effects of aspirin are not the same in all women.
Mathematical model
Visseren and colleagues developed a mathematical model which can predict the effect of taking aspirin in individual women. This enables them to identify those women who will benefit from taking aspirin and those who will not. The positive effect of aspirin is apparently very low in most women. In nine out of ten women, the risk of developing cardiovascular disease decreases by one percent or less. Aspirin was seen to have beneficial effects in only a few women over the age of 65. But in order to prevent just one case of cardiovascular disease, 50 women need to be treated.
“Taking aspirin has no beneficial effect in women under 65,” says Professor Frank Visseren. “This endorses the Dutch policy of reticence in prescribing aspirin to healthy people. In the United States, however, doctors prescribe aspirin for the prevention of cardiovascular disease much more often.”
Polypill
The results of Visseren’s research may also have consequences for the so-called polypill for cardiovascular disease. The idea of the polypill is to give people a daily pill for the prevention of cardiovascular disease; the pill contains aspirin, a cholesterol-lowering drug and blood pressure-lowering drugs. But Professor Visseren and his colleagues do not believe that a polypill intended for healthy people should have to contain aspirin.
The article was published online on November 16, 2011 in the European Heart Journal. The first author of the paper is Jannick Dorresteijn of UMC Utrecht.