How do sex-differences affect atrial fibrillation?

Atrial fibrillation (AFib), the most common type of heart arrhythmia, affects millions worldwide, with significant differences between men and women. While men are more likely to develop AFib, women face distinct challenges, particularly in terms of symptoms, complications, and treatment. These differences offer valuable insights into how the disease progresses and why tailored care, taking sex-differences into consideration, is essential.

Understanding the risk differences in AFib prevalence

Men are generally more likely to be diagnosed with AFib than women, with studies showing that men are around 1.5 times more likely to develop the condition. However, in populations over 75 years of age, women show a greater prevalence, largely due to living for longer on average. For example, in a review of data published in 2019, it was shown that 55% of new AFib cases in older adults were female. This reflects how sex differences in lifespan, can have an impact on overall disease patterns.¹

Men often seek medical care earlier due to more pronounced symptoms like palpitations and chest pain. On the other hand, women frequently report atypical symptoms such as fatigue and dizziness, which may delay diagnosis and treatment.²

This disparity in how AFib presents can affect the timing of diagnosis, which is critical for preventing complications such as stroke.

How do symptoms differ, according to sex?

Men tend to experience AFib with more classic symptoms, including rapid heartbeat and shortness of breath, which are easier for healthcare providers to identify. In contrast, women often report more generalised symptoms such as fatigue, dizziness, and anxiety​.¹

These symptoms, although troublesome, can be harder to connect directly to AFib, leading to a potential under-diagnosis or delayed treatment for women.

Additionally, women are more likely to experience frequent or more severe symptoms than men, even though men are more commonly diagnosed with AFib.² This paradox suggests it’s possible that women may endure a longer period of untreated AFib, before seeking medical attention or receiving an accurate diagnosis.

Stroke risk is a serious complication for women

While women are less likely to develop AFib, they are at a significantly higher risk of stroke once they do. Research has shown that women with AFib face a 1.5-fold greater risk of ischemic stroke compared to men, even after adjusting for age and other factors​.^2,3​

This higher stroke risk may be due to both biological and clinical factors.

Women with AFib are often diagnosed later in life, which can increase their CHA2DS2-VASc scores—a widely used metric to assess stroke risk in AFib patients. More advanced age at diagnosis, combined with additional risk factors such as hypertension and diabetes, all contribute to heightened vulnerability for women.¹

Furthermore, delayed treatment in women can have negative implications for these risks. As a lack of timely intervention to manage conditions effectively, could open the door to the possibility of an increase in symptom severity over time.

Equality in treatment: are women receiving adequate care?

Sex-based differences in the treatment of AFib are well-documented. Women are less likely to undergo invasive treatments such as catheter ablation or electrical cardioversion, despite being more symptomatic​.¹ These disparities raise concerns about whether women are receiving the most appropriate care for their condition.

Women may be steered toward less aggressive treatments due to age or the perception that they are more fragile, but this can be a disadvantage in managing AFib effectively. In a large European registry, women were 1.5 times less likely to receive catheter ablation than men, even though they were more symptomatic.²

This conservative approach to treating women, although perhaps well-intentioned, may leave many women under-treated and at a higher risk for complications like stroke or heart failure.

Medication use also presents challenges for women. Women tend to experience more side effects from AFib medications, such as beta-blockers or antiarrhythmics, which can lead to lower adherence to treatment regimens​.¹ This complicates the management of AFib, as inconsistent medication use can further increase the risk of stroke or other adverse outcomes.

The mechanisms underpinning sex differences

Several factors contribute to these sex disparities, including hormonal influences. Oestrogen, for example, has been linked to increased clot formation, which may partly explain why women with AFib have a higher stroke risk than men​.³

Additionally, structural differences in the heart may play a role. Women with AFib have been shown to develop more atrial fibrosis—a type of tissue scarring—compared to men, which can make certain treatments like catheter ablation less effective​.¹

Pregnancy is another factor that influences AFib risk. Research indicates that women who have had multiple pregnancies are at a higher risk of developing AFib later in life, likely due to the cardiovascular strain experienced during pregnancy​.¹

These unique risk factors highlight the need for more tailored, sex-specific, approaches to both the prevention and treatment of AFib.

What can we do to address these gaps in care

While much progress has been made in understanding how AFib affects men and women differently, there is still a long way to go in ensuring equitable care. More research is needed to explore the underlying mechanisms that drive these sex differences, as well as to improve the early detection and treatment of AFib in women.

Tailoring AFib management strategies to account for these differences could significantly improve outcomes for both men and women. Recognising that women often present with different symptoms and may require different treatment approaches is key to addressing the current disparities in AFib care.

Moreover, one way to better manage care, regardless of sex, is through home monitoring. This can be achieved with the M7 Intelli IT AFib, X7 Smart AFib and the M6 Comfort AFib blood pressure monitors with the latest AFib detection functionality.

In conclusion: with personalised treatments, that take sex-differences into consideration, plus a more flexible approach to monitoring and recording AFib symptoms, healthcare systems can work towards reducing the burden of AFib and its associated complications for all patients – both male and female.