Aspirin, also known as acetylsalicylic acid, is a widely available over-the-counter medication. It has long been recognised for its analgesic and anti-inflammatory properties. However, in past years, there has been growing interest in its potential role as a preventive drug for various medical conditions.

Aspirin in cardiovascular disease?

• In individuals with established cardiovascular disease, aspirin has shown positive results for prevention of future events, such as a heart attack or a stroke. This is commonly known as “secondary” prevention. Hence, the decision to take an aspirin in that setting is always encouraged.

• In patients who do not have an established cardiovascular disease, the use of aspirin would be considered for “primary” prevention: in other words, for the purpose of delaying or preventing a first heart attack or a first stroke.

Until a few years ago, low-dose aspirin at 50 to 150 milligrams daily was also recommended in this cohort, especially if the individual is 50 years or older. However, since 2018, several studies have investigated the role of aspirin in that setting. The most notable ones are called ASPREE and ARRIVE trials. They were large and well designed, and they found that daily low-dose aspirin did not reduce the incidence of major cardiovascular events, and it was associated with a slightly increased risk of bleeding in this “primary” prevention population.

However, the decision to consider aspirin for primary prevention is still pursued case by case, largely determined by the patient’s baseline risk for future cardiovascular events. In that regard, there are many risk assessment scores used that combine age, diabetes, hypertension, high cholesterol and other parameters. If by these scores, the patient is deemed at moderate-to-high future CVD risk, then the use of aspirin could be beneficial.

Another way to make such a decision in primary prevention cases is to use a special imaging study of the coronary arteries called calcium score. Calcium attaches to the coronary vessels if cholesterol plaques are already there. So a high calcium score indirectly implies more cholesterol burden on the heart vessels. With that, aspirin, and as importantly statin use, becomes indicated.

Aspirin for cancer prevention?

The potential of aspirin to reduce the risk of certain cancers has gained considerable attention in recent years.

Studies indicated that aspirin use reduced the long-term risk of colorectal cancer. Subsequent research suggested that the risk reduction was more pronounced with prolonged use and higher dosages.

Beyond colon cancer, emerging evidence suggests that aspirin may also have a preventive effect on other cancer types such as oesophageal, gastric, pancreatic, breast and lung cancers. However, the evidence for these cancer types is still evolving, and further research is needed to establish definitive associations.

Again, the decision to initiate aspirin therapy for this purpose should be carefully weighed against potential side-effects, particularly gastrointestinal bleeding.

Aspirin for Alzheimer’ prevention?

Aspirin's anti-inflammatory properties have sparked interest in its potential for preventing neurological conditions such as Alzheimer's disease, which could be linked to smouldering brain inflammatory changes and consequent cerebral degeneration with mental decline.

In that regard, some observational studies have suggested a possible association between long-term aspirin use and reduced Alzheimer's risk, but more evidence is needed before standard aspirin adoption in that setting.

Aspirin for pre-eclampsia?

Pre-eclampsia is a serious condition that can occur during pregnancy, characterised by a high blood pressure, multiple-organs damage and a potential danger to the mother and foetus.

Several studies have explored the potential role of daily aspirin in preventing pre-eclampsia. They showed a modest risk reduction with low-dose aspirin, in high-risk women. Low-dose aspirin is between 75 and 150mg daily, started at 16 weeks of pregnancy or earlier.

Identifying women at high risk for pre-eclampsia is crucial to determine who may benefit most from aspirin therapy. High-risk factors include a history of pre-eclampsia in prior pregnancies, chronic hypertension, certain medical conditions (such as renal disease or autoimmune disorders), multiple gestations and specific placental abnormalities.

What is the drawback of taking aspirin?

Like any treatment in medicine, aspirin use must be personalised, considering specific patient factors, as aspirin carries an increased risk of bleeding complications, including gastrointestinal and brain bleeding.

In the general population, the risk of such bleeding is about one in a thousand cases, but it is significantly higher in older or frailer individuals, and in patients with other comorbidities such as diabetes, kidney failure, previous gastric ulcer or a blood count disorder. In those patients, the risk of bleeding from aspirin can be ten times higher than the general population.

• Joe Yammine, MD is a consultant cardiologist at the Bermuda Hospitals Board. The information here is not intended as medical advice or as a substitute for professional medical opinion. Always seek the advice of your physician