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Monthly Archives: May 2012

ImageAspirin is arguably one of the greatest drugs invented. Only antibiotics have saved more human lives than this wonder drug. In the history of cardiovascular medicine itself, aspirin has prevented more deaths than all bypass surgeries and angioplasties put together. Considering the low cost of this drug, and the immense cardiovascular benefits it provides, one is not exaggerating when aspirin is spoken of as a public health measure than a mere miracle drug.

The simplicity of the aspirin’s action lies in its ability to prevent platelets, small blood cells, from clumping together and forming clots within blood vessels. Typically, it is these clots in the arteries that cause heart attacks and paralytic brain strokes. Needless to say, both heart attacks and strokes are often fatal.

In patients who have already had myocardial infarction or stroke, aspirin treatment is mandatory to prevent recurrent events. This is spoken of as secondary prevention. Given the impressive cost-benefit ratio, doctors have always looked at aspirin as a potential drug to prevent first heart attacks and strokes in patients who have never experienced cardiovascular events. This ability to help in primary prevention has been a matter of study, now for decades.

The flip side to daily aspirin treatment is its side effect. By virtue of its ‘blood thinning’ effect aspirin is capable of causing unexpected bleeding. Often, the bleeding is from the stomach & intestine, (‘peptic ulcer bleeds’). But, any internal hemorrhage can result, including rare instances of brain hemorrhage in some patients. Some minor injuries, which may otherwise be well tolerated, can result in serious bleeding in patients on aspirin therapy.

Traditionally, patients who were deemed to be at a higher risk for developing heart attacks and strokes were put on aspirin on a regular basis. Typically, these were patients with diabetes, hypertension, high blood cholesterol, smokers and patients with family history of heart attacks. Higher the risk – e.g., a diabetic who is also a smoker with a family history, greater was the benefit provided by aspirin therapy. In an analysis published in 2011 (link), investigators from Brisbane concluded that the aspirin not only protected against heart attacks and strokes, but reduced overall risk of death.

However, a new meta-analysis of a number of previous studies, published in the Archives of Internal Medicine has contested this traditional wisdom. Prof Kausik Ray from St George’s University, London, who is the senior investigator of this analysis, has spoken extensively on the new conclusions arising out of this analysis about aspirin (link). The paper says that in most instances aspirin only protects against ‘non-fatal’ heart attacks. Regular intake of aspirin does not protect against mortality. And, the worst part of it all is that aspirin caused an increase in the risk of ‘non-trivial’ bleeding (translates as serious bleeding needing hospitalization, blood transfusion, necessitating surgery or leading to death).

With this the debate as to whether aspirin should be prescribed to patients who are perceived to be ‘at risk’ for heart attacks & strokes has come to a full circle. Traditional wisdom is being questioned.

But given its intuitively attractive risk-benefit ratio, as far as protection against heart attacks are concerned, my personal opinion is that one can’t be categorical about whether aspirin should or should not be used.
Individuals have varying risk of developing heart attacks based on their medical history. Some are at very high risk whereas some have a negligible risk. Likewise, bleeding risk too varies between individuals. The trick with preventive cardiovascular medicine is to identify patients at high risk of cardiovascular events but lower risk of bleeding and offer primary protection with aspirin. Higher cardiovascular risk can be identified with use of risk calculators which are recommended by experts in the USA or Europe.

In the practice of cardiovascular medicine ‘cure’ has never been cost effective with burgeoning hospitalization costs for angioplasties and by-pass surgeries. With cardiac disease prevalence assuming epidemic proportions, one can safely say that the day is not far when not enough hospitals and doctors will be available to treat all cardiac patients especially in a country like India. Thus, despite (?over)cautious observations such as this report, primary prevention with aspirin will continue to hold a key for the future.

(Image courtesy Harvard Health Blog)