Aspirin: Does it really prevent hearat attacks and strokes?
Is an Aspirin a day really beneficial?
Every day four million Canadians wake up in the morning and take a coated 81mg Aspirin because they feel it will be help them prevent having a heart attack or a stroke. It may help some of them but it actually may be doing others more harm than good.
A few months ago The United States Food and Drug Administration refused a decade-old request from Bayer Health Care LLC, the maker of Aspirin, to label this popular drug as an effective way of preventing heart attacks and strokes. This came as a surprise because since about 1980, cardiologists and family doctors have been recommending that their patients take an Aspirin every day to prevent cardiovascular events.
It has become routine that if you are over fifty, your doctor will tell you to take a baby aspirin a day even if you have nothing wrong with you. On the other hand if you have diabetes or you have had a coronary incident they will insist you take it. It is important to note that you are instructed to take an 81mg enteric coated baby aspirin and not the regular 325mg aspirin which is used for pain and headaches.
There are also many studies showing that a baby aspirin daily can help prevent colon cancer, breast cancer and most recently pancreatic cancer even though the evidence for all these claims is very scant and based on very small studies.
The United States Food and Drug Administration were asked the question, “Can an aspirin a day help you ward off a heart attack or a stroke? “The large study that answered the question began with the words. “That depends. Scientific evidence shows that taking an aspirin daily can help prevent a heart attack or a stroke in some people, but not in everyone. It can also produce some unwanted and in some cases severe side-effects.”
The indisputable evidence is that taking an aspirin a day can significantly reduce the risk of another heart attack or stroke by twenty five per cent in people who have already suffered significant cardiovascular problems.
The controversy involves the people who have never had a cardiac incident and are considered healthy. The studies show that there is no benefit for these people, only risks of developing a harmful side-effect from the drug.
Aspirin reduces blood platelets and this reduces the clotting ability of your blood. These internal blood clots in your arteries and capillaries are the cause of most heart attacks and strokes and so a baby aspirin once a day seems like a logical choice as we age. The problem is that if Aspirin were discovered today it would definitely be a prescription drug and not available over the counter. The reasons for this are the many serious side-effects caused by this drug. It can cause all types of gastrointestinal bleeding including severe stomach ulcers. Some of these ulcers do not cause any pain but are only detected when blood is discovered in the stool. Long term use can even cause different types of gastrointestinal cancers such as stomach cancer.
The axiom in medicine is “Do the benefits outweigh the risks?”
Sometimes this can be a very fine line.
The most recent study on the benefits of Aspirin was published in the Archives of Internal Medicine in 2012. The researchers found that for every 120 people who took a baby aspirin once a day, one cardiac event was prevented. However, using the same criteria they found one gastrointestinal bleeding event occurred once in every 73 people taking Aspirin.
They concluded that almost twice as many people would be harmed as will benefit from a daily regimen of Aspirin. There was no effect on longevity or mortality found in the study.
Benefits to Woman versus Men
In a very recent study done at Duke University by Jeffrey S. Burger MD and published in the Journal of the American Medical Association in the Jan 18 edition this year, there were significant different benefits depending on your sex. The study involved 51,000 women and 44,000 men and found that an aspirin a day reduced cardiac incidents in men by 32 per cent but only by 17 per cent in women. However, it also concluded that 70 per cent of both women and men in the study developed severe gastrointestinal bleeding and stomach ulcers.
Although the FDA refused to allow Aspirin to be labelled as a drug that would prevent heart attacks and strokes they did say that the ultimate decision rests with the individual physicians and their patients.
Guidelines in Canada and the US differ significantly on the issue of Aspirin for cardiac prevention.
The American Heart Association recommends daily aspirin for anyone with moderate risks for heart disease, even if they have not had a heart attack or stroke. Risk factors include smoking, obesity, high blood pressure, high cholesterol or diabetes.
The Canadian Cardiovascular Society guidelines are much more cautious. They actually say that routine administration of daily aspirin is NOT recommended for everybody but can be of value to select patients. In spite of the recommendations 40 million Americans and 4 million Canadians take an aspirin every day regardless of the fact that most of these people are healthy and probably don’t need it.
Aspirin was discovered in 1897 when it was synthesized as acetyl salicylic acid. It does differ from the original salicylic acid which can be found in white willow bark and has been around since the time of Hippocrates. However, only the addition of the acetyl group (COCH3) to the salicylic acid molecule gives it the ability to reduce blood platelets and thin the blood.
We know that aspirin can reduce inflammation, take away the pain of a headache or injury and when we were children it was used to bring down our fevers. However because of the association between Reye’s syndrome (a disease of the liver that could cause death) and aspirin, we stopped giving to our children and switched to Tylenol. However, whether it is effective in reducing heart attacks or strokes still cannot be determined even now. Taking any drug, and Aspirin is certainly a drug, comes down to a mutual decision made between you and your physician based on your existing medical conditions. As I said earlier you must always consider the benefits of a drug versus the risks and weigh them very carefully before embarking on an aspirin regimen.