When doing nothing does harm

Do no harm. This injunction and its modern variants are among the most basic tenets of the Hippocratic oath that doctors take when they start out in medicine. But what happens when a treatment that saves lives through treating one disease increases the risk of patients becoming ill, or even dying, of another? And what if this process has the potential to disproportionately affect one sector of society, one sex?

As Australia heads into Women’s Health Week, these questions reverberate not just for what they tell us about the assumptions and inequities that still underpin our society, and our medicine, but also for what they tell us about what we must do to improve – and save – women’s lives, starting now.

It’s a challenge the Heart Foundation is tackling on several fronts, most recently through a major investment in research designed to plug gaps in our understanding of the prevention and treatment of heart disease, with a particular focus on women. More on that in a minute.

But first, let’s talk about cancer.

This year, an estimated 145,483 new cases of cancer will be diagnosed in Australia. Fortunately, an increasing number of these patients will survive due in part to advances in treatment. Australia now has one of the highest rates of cancer survival in the world. Yet at the same time, a growing number of cancer survivors are going on to die of heart disease.

This pattern is not unique to Australia. A recent paper from the European Society of Cardiology describes “a growing epidemic of cardiovascular disease” in patients during and after cancer treatment. International studies have shown that cancer patients are up to 15 times more likely than those without a history of cancer to develop heart disease.

The reasons are intertwined, and derive in part from ageing populations and overlapping risk factors (including obesity and smoking) for the two conditions. But for a significant number of cancer patients, the treatment itself will leave a potentially lethal legacy.

Intensive cancer regimens, including types of chemotherapy, immunotherapy and radiotherapy, can damage the heart muscle and valves as well as blood vessels. This collateral damage can lead to heart failure and premature death in people with and without a history of heart disease, and is the focus of the emerging field of cardio-oncology.

Paradoxically, a recent Australian study, partly funded through a Heart Foundation research grant, found that cancer patients and survivors are less likely than people without a history of cancer to be taking drugs to prevent blood clots or treat high cholesterol – despite being at similar risk of heart disease and stroke.

What does all this have to do with women?

There is evidence that women may be at particular risk from cardiotoxic treatments. Studies show that women who had cancer as children are at greater risk than men of going on to develop conditions including heart failure. Women exposed to ionising radiation during therapy for breast cancer may have an increased risk of heart attack or heart disease later in life, according to some studies.

We know too that a sustained focus on, and investment in, the treatment of breast cancer has resulted in many more women now surviving that disease.  

Sadly, the same cannot be said of women with heart disease, which kills more than twice as many women as breast cancer does, but which has traditionally been seen as a male problem.

Underpinning all this is the fact that gender disparities in research, prevention, diagnosis and treatment mean that heart disease in women is less well understood and treated than in men. Not only are many of our assumptions based on male data and physiology, but women are less likely to receive in-hospital therapies and ongoing treatment.

This is a global problem, but it has particular resonance here in Australia, where a 2019 report in the Medical Journal of Australia noted that medical research in Australia now lags behind North America and Europe in recognising sex and gender as “key determinants of health”.

In June, the Heart Foundation and Federal Government jointly announced $8 million for cutting-edge research into Australia’s biggest killers, heart disease and stroke, an initiative that will benefit all Australians while working to redress these sex and gender biases. The strategic grants focus on four emerging fields of cardiovascular research, and include $2 million to bring cardiologists and oncologists together to collaborate on preventing and treating heart disease in cancer survivors.

Two other projects will in turn focus on predictive modelling to help accurately predict individual risk, and secondary prevention, such as supporting patients to attend cardiac rehabilitation – both areas in which women have been underrepresented. The fourth project focuses directly on women and heart disease, aiming to address sex and gender-based disparities in treatment and care.

As I’ve said before, we are still a long way from heart health equality. We have work to do, including overturning some entrenched beliefs. But doing nothing is not an option.

If you would like to help the Heart Foundation further address such inequities donate now.

For the women you love.