Aspirin may prevent heart attacks in men more than women
Publication Date:19/10/2007
A daily aspirin is recommended to prevent heart attacks in people at high risk of having one. Now new research suggests that although aspirin helps protect men against heart attack, it may not work as well for women.
What do we know already?
A lot of research has shown that taking a low-dose aspirin daily can reduce the chances of having a heart attack by about one third. Aspirin is often prescribed for people at high risk of having a heart attack or stroke.
But the research on aspirin to prevent heart attacks is quite mixed. Some studies have shown a big effect, while others have shown no effect at all. Scientists have been trying to work out what caused the differences between the results. This might help us find out who benefits most from taking aspirin.
A low-dose aspirin is safe for most people. But, because aspirin stops your blood from clotting, some people taking aspirin find that cuts take longer to stop bleeding, and they bruise more easily. Also, aspirin can irritate your stomach lining. Rarely, this can cause bleeding in the stomach.
If aspirin is protecting you from heart attacks, the risk of these side effects is worthwhile. That's why it's important to know whether aspirin works for everyone, or just for some people.
What does the new study say?
The new research looked at 23 studies into taking aspirin to prevent heart attacks. Researchers looked at the data to see if the differences between the results of the studies could be explained by the numbers of men and women taking part.
The researchers say their results show men are much more likely to benefit from taking aspirin than women. They say that trials with mostly men in them showed the biggest protective effect from aspirin, while trials with more women in them showed little or no effect.
The researchers say they don't know why women don't seem to get the same benefit from aspirin that men get. They say it might be because more women have a condition called aspirin resistance, where aspirin doesn't make a difference to blood clotting.
Where does the study come from?
The study was carried out by researchers at the University of British Columbia, Vancouver, Canada. It was published in an online medical journal, called BMC Medicine, owned by a publishing company called Biomed Central.
How reliable are the findings?
The study is interesting, but the results aren't certain enough to change the way that doctors try to prevent heart attacks. We don't know what other factors might have made a difference between the results of the different studies.
The researchers said they took into account how old the people in the studies were, and whether they smoked. They said this didn't make a difference to their findings, but other things (like what other diseases they had) might.
Importantly, the researchers didn't look separately at the individual results of the men and women in the studies. So we don't know for sure that, in the studies with both men and women, the men in the studies did better than the women. We only know that studies with more men in them had more positive results than studies with more women.
Also, some of the studies looked at people who were healthy at the start of the study, while others looked at people who'd already had one or more heart attacks or strokes. In some studies, the dose of aspirin was much higher than others. So it's hard to untangle what made the biggest difference between the studies.
What does this mean for me?
Daily low-dose aspirin is usually recommended for people who:
- Have had a heart attack or stroke before
- Have cardiovascular disease
- Have more than a 20 percent chance of having a heart attack, and are aged over 50
- Have diabetes, and are aged over 50 or also having treatment for high blood pressure.
If you are in one of these groups, taking aspirin may prevent a heart attack by stopping your blood from forming clots. The research doesn't change these recommendations.
It's important to note that the study doesn't say that no women benefit from taking aspirin to prevent a heart attack. Some women might benefit more than others. We need more research to find out.
Also, the study just looked at the effect of aspirin on preventing heart attacks. Many people also take aspirin once a day to prevent stroke. We don't know whether this works differently for men and women.
What should I do now?
If you are taking aspirin to prevent a heart attack, and you're a woman, there's no need to change your treatment as a result of this study. Don't change your heart attack medicine without talking to your doctor first. Low-dose aspirin has few serious side effects, and it may be protecting your heart.
If you are considering taking aspirin to protect your heart, it's a good idea to talk to your doctor first. He or she can advise you about your risk of having a heart attack, and tell you what's the safest dose to take.
From:
Yerman T, Gan WQ, Sin DD. The influence of gender on the effects of aspirin in preventing myocardial infarction. BMC Medicine. 2007; 5: 29.
To find out more, see our information on treating a heart attack.
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© BMJ Publishing Group Limited ("BMJ Group") 2007. All rights reserved
This information does not replace medical advice. If you are concerned you might have a medical problem please ask your Boots pharmacy team in your local Boots store, or see your doctor.
