The way to a woman’s heart

10 April 2018

As we grow older, our chances of developing heart disease gradually increase. However, misdiagnosis of the condition among women, relative to men, remains at worryingly high levels. Greg Noone talks to Professor Maja-Lisa Løchen about the steps that can be taken to bring female heart disease into sharper focus.

The masculinity of the heart attack begins with syntax. The phrase suggests a sudden, targeted form of violence – an ambush, an assassination – expressed through a frenzied and overwhelming assault. All of this is consistent with its most famous symptom – a sudden, crushing pain in the chest – dragging the victim down into a weakened and feeble state.

The subliminal maleness of heart disease in mainstream science has served to obscure the vulnerability of women to the condition, at a scale that is only now becoming clear. According to the US Centers for Disease Control (CDC), heart disease is now the leading cause of death for women in the US.

Despite this, only 54% of women were able to recognise this fact, while two thirds of women who died of coronary heart disease exhibited ‘no previous symptoms’.

More recent breakthroughs in our understanding of female heart disease suggests that the last two figures are linked. While it is possible for some women to exhibit no symptoms at all, others may experience nausea, sweating, a loss of hand-eye coordination, and pain in the jaw and neck, ailments that are not immediately associated with heart trouble. In one survey of female victims of acute myocardial infarction in 2015, researchers found that doctors had overlooked symptoms that, in some cases, had persisted over several weeks. “Almost all of them reported that they had to convince people, [and] almost ‘sell’ the idea that they might have something serious,” the report’s co-author, Dr Harlan Krumholz, told The Atlantic.

Deep divide

Maja-Lisa Løchen first understood the depth of the gender bias in cardiology during her time as a medical student in Tromsø in the 1980s, when she saw her PhD supervisor’s reaction to her interest in that area of research.

It’s been my focus all the way, to look for it, to try and understand the differences between men and women when it comes to heart disease.

“He was a very, kind of...” says Løchen, pausing for a moment. “Not really angry, but he didn’t like my focus on sex differences. It was not very popular at that time and they did not think that there really were any differences between males and females.”

Now a professor in cardiology herself, with a specialisation in population studies, Løchen has spent most of her career up until now proving him wrong. “It’s been my focus all the way, to look for it, to try and understand the differences between men and women when it comes to heart disease,” she says. “And what is really great for me, now, is that this is really a big research area worldwide.”

One of her most recent reports, titled ‘Hidden Hearts’ and published by the Mary Mackillop Institute for Health Research in October 2016, is part of a series of investigations Løchen has conducted into the role gender differences play, not only in the diagnosis of heart disease in women, but also its treatment and causes. Focusing on Australian women, Løchen and her fellow researchers found that the condition was responsible for more than 31,000 deaths a year, surpassing several forms of cancer as the dominant cause of death for women in the country. Out of this total, almost 3,000 women were predicted to die before they were even given medical assistance.

In response, ‘Hidden Hearts’ recommended raising national awareness of cardiovascular disease, in particular its toll on women, as well as a revision of the guidelines for its treatment and management. Løchen and her fellow researchers also recommended funding new studies that would help lift the veil of ignorance surrounding gender differences in heart conditions in Australian medicine, and alleviate the A$3 billion a year spent on treating its victims.

Overarching view

Compared with men, women have smaller body sizes on average, a different selection of hormones and a higher amount of body fat, all of which can lead to more severe side effects if they are prescribed heart medication in dosages originally formulated with male patients in mind. Women also have smaller hearts and arteries which, in practical terms, can mean that certain forms of heart disease are more difficult to spot.

“Females, more often than males, have disease in the microvasculature of the heart, which is not possible to diagnose with angiography,” says Løchen. “You have to have different diagnostic methods to discover it, which is more complex.”

It is more complex because, even as gender differences in heart disease began to be recognised from the 1980s onwards, centuries of consensus as to the maleness of the condition had deeply influenced the course of research into the phenomenon. Studies linking heart disease with cholesterol and aspirin intake included few, if any, female test subjects, and therefore symptoms of the condition in the male body became the template for women, too.

The reality was often more complicated. Løchen herself was only 12 years old when her mother suffered her first heart attack, following months of shoulder pain diagnosed by her local GP as muscle strain or rheumatism. She typified attitudes among many women who suffer from symptoms of heart disease, such as pain in the neck, chest or abdomen, that they nonetheless consider too trivial to justify a trip to the doctor.

The long-term causes of heart disease also vary between the genders. While both sexes are equally vulnerable to common risk factors, such as smoking and poor dietary habits, cardiovascular disease often strikes men earlier in life. “In women, heart failure is more often caused by older age, hypertension and obesity,” Løchen explains. “And this kind of heart failure in women is very often undetected.”

Females, more often than males, have disease in the microvasculature of the heart, which is not possible to diagnose with angiography.

All of these factors were present in the data presented by ‘Hidden Hearts’. What makes it unique is Australia’s large indigenous population, who sustain a much higher risk of heart disease thanks to their societal marginalisation and all the consequent impact this has on the diet and lifestyle of Aboriginal women.

“They are poor, they are often [unemployed], they have no education and they smoke like we did in your country, in my country, 50 years ago,” explains Løchen. “It’s very much due to preventable risk factors.”

Homeland concerns

The inclusion of such a large indigenous population makes Australia more or less unique when it comes to population studies of heart disease in the Western world. In Løchen’s home country of Norway, for example, the gender differences in heart disease patients are drawn primarily along geographical and educational lines. After all, only 13% of the population actually smokes. However, those who do are predominantly concentrated in places like Finnmark and eastern Oslo, as opposed to the more affluent areas west of the country’s capital.

Many of Løchen’s insights were gleaned during the research period for Women’s Hearts, a compendium of case studies on female heart disease patients she co-authored with journalist Eva Gerdts. Written for the widest possible audience, the book made a singular impact in publicising the pervasive gender imbalance in treatment and perception of the condition. “It’s written for health workers and journalists, but also for the general public,” says Løchen.

Her next project will continue in this vein. In 2015, The Arctic University was invited by C Noel Bairey Merz, director of the Women's Heart Center at the Cedars-Sinai Heart Institute, “to participate in a study to develop what we call a female-specific risk calculator”, she explains. While this work has not begun just yet, the women have already collaborated on a research paper on gender difference in heart disease.

There are already many different types of risk calculators for heart disease, among men and women, and at the European and national level. They are, however, lacking when it comes to measurement of risk factors unique to women.

There are, Løchen says, “six specific risks” missing, including whether or not the patient has developed hypertension or diabetes during pregnancy, or inflammatory diseases such as rheumatoid arthritis. Many of these conditions are more prevalent in women and remain uncovered by existing risk calculators.

“They’re [the US working group] going to use our data from our population to work with her on this,” explains Løchen. “Hopefully, in the future, we’ll get good funding. [It’s] a research area that many people are looking into, but it’s not really been developed yet.” One hopes that it will, sooner rather than later.

Women suffering heart disease sometimes don't seek help from a GP because they consider their symptoms too trivial.
Heart disease may sometimes be harder to spot in women than men.
Professor Maja-Lisa Løchen: Professor Maja-Lisa Løchen is professor of preventative medicine at UiT The Arctic University of Norway in Tromsø. Her most recent book is Women’s Hearts: A medical textbook on common heart diseases, co-authored with Professor Eva Gerdts.

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