The fight over sex discrimination is often waged in the courtroom or political arena. But the reality is that inequality between the sexes reaches into all aspects of life, including health. To say that this is a life or death battle is not an exaggeration.

Study after study shows that compared to men with similar cardiovascular conditions, women are less likely to receive timely and appropriate medical care. A study lead by Dr. Pooja Dewan, published in the Journal of the American College of Cardiology, provides a progress report on recent efforts to reduce the gap in cardiovascular care between the sexes. While there are some positive findings, it is clear that we still have a long way to go to realize equal care.

Progress

The study by Dr. Dewan and her colleagues from the British Heart Foundation Cardiovascular Research Centre at the University of Glasgow examined data collected as part of two large clinical trials. These two clinical trials – PARADIGM-HF and ATMOSPHERE – included over 15,000 patients and tested new treatment options for patients with heart failure. Dr. Dewan’s group re-assessed data collected in these studies and compared the results for men and women.

Women in PARADIGM-HF and ATMOSPHERE trial were more likely to be older, obese and have high blood pressure. Men were more likely to have a history of heart attacks, stroke and coronary artery disease. Some treatments for heart failure were similar between the sexes: diruetics, beta-blockers and mineral corticoid receptor antagonists were prescribed at similar rates for women and men.

Room for Improvement

While the study from Dewan and colleagues show equality with some treatments, key differences between the sexes remain.

Digoxin, a heart failure medication that helps the heart to contract, was prescribed to women at a slightly higher rate than men. In this case more may not be better – digoxin may have negative effects in women (Rathore et al., 2002).

The cholesterol-lowering group of drugs called ‘statins’ were much less likely to be given to women. On its face this seems like discrimination. However, lower rates of coronary artery disease in women may explain this difference in statin use.

Finally, even though diruetics were given at equal rates to men and women, Dewan suggests that higher rates of fluid retention in women warrant a higher rate of use of these drugs by female heart failure patients.

Perhaps the most striking issue was the low use of cardiac devices in women. Heart failure patients are at high risk of developing heart rate disorders called arrhythmias. These irregular beating patterns decrease the ability of the heart to function and increase the risk of blood clots. Blood clots may cause heart attacks or strokes. Cardiac devices like pacemakers or implantable cardioverter-defibrillators (ICD) help to maintain the normal rhythm of the heart. Women were up to 50% less likely to receive these devices than men were, despite the fact previous studies show women strongly benefit from their use (Zusterzeel et al., 2014).

Treatment Isn’t Just a Pill

The treatment of heart failure doesn’t end with a drug prescription. Heart failure patients benefit from rehabilitation and exercise programs. These activities help to enhance the health of heart failure patients and improve their quality of life.

Dewan and colleagues found that women reported greater physical limitations, higher social limitations and an overall lower quality of life with heart failure. The reason women experience a lower quality of life after leaving the hospital may be related to inequality in enrollment in exercise and rehabilitation programs. Previous studies have found that cardiac rehabilitation is generally under-utilized, with only one-third of all patients enrolling in a program (Fang et al., 2015; Grace et al., 2014). But participation by women is even lower. Compared to men, women in these programs also have poorer adherence and higher dropout rates (Bittner, 2018).

The reasons for these differences are not known but may include a lack of communication between patients and healthcare professionals, socioeconomic barriers faced by women with heart failure, and the older average age of female heart failure patients. What is clear is that the lack of access to cardiac rehabilitation and disease management programs likely contributes to a lower quality of life for women with heart failure.

A Life-Threatening Knowledge Gap

In 1961, Kannel and colleagues first described differences in the rates of heart disease between men and women. Since then it has become widely accepted that sex influences the risk for cardiovascular disease. But in 2001, a report on women’s health noted that sex and heart disease remained largely unexplored (Institute of Medicine). Almost a decade later the Institute of Medicine (2010) produced a progress report that lauded advances in sex-specific treatments and management for some types of heart disease, while bemoaning the continued lack of sex-specific analysis of heart failure. The result, they noted, was the persistence of a knowledge gap about how biological sex affects cardiovascular disease in general and heart failure in particular.

Why does this lack understanding of heart failure in women remain? Clinical trials represent the most current research into the diagnosis and treatment of heart failure. Historically, women have not been widely included in these studies. A 2018 review by Eisenberg and colleagues showed that in 22 clinical trials, none had more than 40% female patients.

Research into the basic science of the heart often focuses on a single sex because of the high costs of including twice as many research subjects. Unsubstantiated concerns about including females whose sex hormone levels fluctuate naturally lead many researchers to include only males. Fortunately, agencies that fund science are increasingly promoting or even mandating that studies include both sexes in research, which should make a difference.

Consequences

What effect does our lack of understanding about the role of sex in heart failure have on patients? To put it bluntly: a hugely negative one.

Clinical trials test which treatments are most effective for which patients. For heart failure studies, the vast majority of these patients men. As such, information used to establish clinical guidelines are largely based on information collected from men. Research shows that the types of heart failure that occur most commonly in men are not the same as those that occur in women. This means diagnosis, treatment and rehabilitation strategies are unlikely to be the same.

Equal, But Not the Same

Significant advances have been made towards achieving equality of the sexes over the last half-century. But there is still a long way to go. In cardiology, one problem that remains is the issue of inclusion. Until women are equally included in research and clinical trials, equality will remain elusive. Adding to this challenge is the increasing understanding that heart failure in women is not the same as in men. This means that equality is unlikely to come from prescribing the same treatments, but rather by creating a new knowledge base about heart failure in women.

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