Registry data suggest that while in younger individuals the prevalence of heart failure is higher in men than women, the trend reverses over the age of 65 years, when a greater proportion of women than men have heart failure.

According to Professor Marisa Crespo-Leiro (University Hospital Coruña, Spain), cardiovascular disease is the leading cause of death in older women, and women are more likely to be hospitalised for their condition. Registry data suggest that while in younger individuals the prevalence of heart failure is higher in men than women, the trend reverses over the age of 65 years, when a greater proportion of women than men have heart failure. This age-related pattern of gender-based heart failure prevalence is a reflection of the fact that women are more likely than men to develop heart failure with preserved ejection fraction (HFpEF). The pathophysiology of heart failure differs between the sexes and this may be compounded by a greater increase in the rates of risk factors, including iron deficiency, diabetes, obesity, hypertension and auto-immune diseases, in women compared with men.

In terms of treatment, studies suggest men are more likely to receive optimum treatment than women. In a US study of cardiac resynchronisation therapy (CRT), women received CRT less frequently than men, despite deriving greater benefits from it. Another recent study reported that women were less likely than men to receive continuous flow left ventricular assist devices (CF-LVAD) and that sex was a significant predictor of waitlist mortality.

Women are less likely to appear in registries, which may suggest that they receive treatment less frequently than men, explains Prof. Crespo-Leiro. In the ESC Heart Failure Long-term Registry (2011 to 2013), only 37.3% of patients with acute disease and 28.8% with chronic disease were female. In the SwedeHF Registry, 41% of participants were women. As being included in the registry was associated with reduced all-cause mortality, this could suggest that women are at a potential outcome disadvantage.

The underrepresentation of women in clinical trials is particularly concerning, says Professor Theresa McDonagh (King’s College Hospital, London, UK), as these trials form the basis of the process by which heart failure treatment safety and efficacy is measured and gender biological, phenotypical and hormonal differences may play a role. Currently only around one-third of participants in phase III trials are women and the problem extends back to the first-in-human studies. Insufficient female participation may mean a lack of information regarding the best treatments and regimens for women with heart disease. Prof. McDonagh suggests that reasons for the relatively lower numbers of female clinical trial participants include the older age of women with heart failure—and the fact that the age-associated increase in comorbidities will exclude them from many trial protocols—the greater risk aversion of women compared with men and the fact that many women will be carers and so will lack the time for trial participation. The relatively poorer representation of women in clinical trials has been recognised by the major cardiology societies and licensing agencies and efforts are being made to encourage women to take part.

Clinicians can help the recruitment of women into trials by being more gender-specific when investigating concerns that deter individuals from taking part.

“We still have a lot to learn about heart failure in women,” says Prof. Crespo-Leiro, “but we must make sure that we do not limit their opportunities to improve their outcomes.”

This article is a news release from Heart Failure 2019 Congress. Read the original here.