For many years, there has been a relatively accepted notion that taking a baby aspirin every day (100 mg) was a good preventative strategy to prevent heart attack and stroke. The information to support this concept came from a number of trials in people with established vascular disease or those with strong risk factors, showing around a 25% reduction in vascular events by taking around 100 mg of aspirin on a daily basis.
Recently, however, there have been three major trials of primary prevention i.e. taking a therapy before the disease has manifested, to show no clear benefit from taking aspirin. There is no doubt that aspirin does reduce vascular risk and there have been a number of trials even suggesting a small but definite reduction in many of the common cancers (in particular bowel cancer) from taking this low-dose of aspirin on a daily basis.
So, what is the problem? I think it is best to illustrate this with a personal anecdote. A number of years ago, when my mother was alive, she was living on the North coast of New South Wales and I had not seen her for over 9 months. She arrived at my house for a holiday and I noticed immediately that she was extremely short of breath and looked very pale and tired. I then switched into doctor mode and collected some simple blood tests showing that my mother’s haemoglobin level (an indication of the amount of red cells in the body) was incredibly low. I asked my mother had she had any gastrointestinal bleeding or noticed bleeding from any other orifice and the answer was no. Had she had a change in her bowel habit? The answer was no. Had she had reflux or any form of dyspepsia? Again the answer was no. I then asked was she taking any new medication such as arthritis pills and again the answer was no. I then said “Mum, are you taking aspirin?” She said “yes, I am taking aspirin.” I said why are you taking aspirin? She replied, I read it was good for the heart!
I pointed out to my mother that I had been a cardiologist for the last 25 years and she could have asked me. She replied, I did not want to bother you son and I answered by saying you are bothering me now. I organised a gastroscopy and colonoscopy and my mother had severe gastritis as a consequence of taking a daily aspirin.
A recent study showed that in the US alone there are over 6 ½ million adults who daily taken aspirin to prevent heart disease without a doctor’s recommendation. The study demonstrated that 50% of people over the age of 70 are taken daily aspirin as a form of primary prevention. Aspirin basically reduces platelet stickiness and thus thins the blood. But in people taking aspirin for primary prevention the bleeding risks appear to outweigh the cardiovascular benefits. It appears that 10% of people taking aspirin do suffer some form of upper gastrointestinal problem with peptic ulceration and/or bleeding. The risk appears to be higher in older people and those with a past history of peptic ulcer or gastrointestinal bleeding.
If you include a doctor’s recommendation to take aspirin it appears that ¼ of people over the age of 40 are taking aspirin which equates to 2 million Australians.
What is the answer here? It is my opinion from reviewing all the recent studies that there is no place for daily aspirin as a preventative but it certainly should be taken in people who have established vascular disease such as a prior heart attack, stent, coronary artery bypass grafting or stroke or are at high risk for cardiovascular disease such as those with cholesterol abnormalities, high blood pressure that is being well treated, cigarette smokers, those with risk for diabetes or a strong family history of early vascular disease. There is also probably some benefit for people who are at a high risk for bowel cancer. If you have poorly controlled blood pressure, there is always the risk for cerebral haemorrhage, which can be made worse by aspirin.
It is important to realise that aspirin is a pharmaceutical drug with significant side effects and with all aspects of medical care you should discuss this with your doctor prior to commencing any therapy. Although it is my opinion that aspirin is one of the greatest drugs ever discovered and prescribed, there are no totally safe pharmaceutical agents and it is important for an expert to decide whether the benefits outweigh the potential harm.