Getting to the Heart of the Matter: Sex Differences in Cardiomyopathy

Artwork by Mengmeng Tu, MSc Science Communication student

This festive period, Three Wise Women from the Faculty of Medicine will be giving us the gift of wisdom.

Could variation in the architecture of men and women’s hearts explain why their risk of cardiomyopathy differs? Dr Paz Tayal, Clinical Senior Lecturer in Cardiology at the National Heart and Lung Institute is investigating this with the aim of improving outcomes for patients affected by this disease of the heart muscle. Dr Tayal also discusses the ‘juggle struggle’ of balancing work and family life, and the importance of truth telling in academic medicine.

As winter sets in, I start to pack away the summer dresses and bring out the woolly jumpers and sturdy boots. When I do this, I will not be going into my husband’s closet to find things that fit me, nor indeed will I be wearing his shoes.

That seems obvious right, because we are different sizes.

We don’t think twice about that, yet in medicine, we are only just beginning to realise that male and female patients might need to have tailored ways to diagnose and treat disease.

Even in health, male and female hearts are not the same. At birth, the hearts of male and female babies are about the same size. However, at puberty, male hearts have a faster period of growth compared to female hearts. Whilst this eventually settles down, throughout adult life the mismatch persists, and the female heart remains smaller.

Male vs. Female Hearts

You might say female hearts are smaller than male hearts because generally females are smaller than males. You’d be right, but that’s not the full explanation. The female heart is not just a scaled-down, smaller version of a male heart. It is completely unique, both at the big picture functional level and small picture cellular level. Female hearts have more heart muscle cells than male hearts, which we would not expect from the size difference. We are just beginning to understand what this might mean.

I am a cardiologist and a scientist. I study how and why the hearts of male and female patients differ in disease, and what impact this might have for how we diagnose or treat heart muscle diseases (cardiomyopathies). Heart muscle diseases affect up to 1 in 250 people, often at a young age. Whilst many patients can be treated with medications, a rare few experience very serious complications from their condition such as sudden death or needing a heart transplant. We urgently need ways to improve outcomes for all patients with these diseases.

These heart muscle diseases can occur due to abnormalities in the genes involved in the way the heart works. Sometimes having the genetic problem is enough to cause disease, but in some patients an additional trigger is needed to develop the disease. We have studied this with alcohol, certain viruses and chemotherapy. We call these additional triggers ‘environmental factors’.

Sex specific research

Female patients have a totally unique set of environmental factors that are generally not accounted for when treating patients or studying heart disease. Each female has a reproductive lifespan, spanning from menarche to menopause, and for some, there are pregnancies, multiple pregnancies, pregnancy complications, infertility, polycystic ovary disease, and early menarche or early menopause along the way. The impact of these reproductive factors on the risk of developing heart muscle disease, or of getting complications from heart muscle disease are currently not understood. This is what I hope to tackle in my research programme, which began this year with the award of an MRC Clinician Scientist Fellowship.

I will explore what the impact of reproductive risk factors are in the heart muscle diseases and I will look at whether we should have sex-specific criteria for diagnosis and treatment. I will also see if there are sex-specific signals in heart gene abnormalities.

Sex specific research, that is, research specifically designed to address the similarities and differences between male and female patients has been overlooked in medical research. We have been very good at studying the minutiae of an organ, or a fancy biomarker, but sometimes the bigger picture view gets missed.

As a result, many treatments have been trialled on study groups that are predominantly male, and then applied to female patients on the assumption that they will respond similarly. For example, many trials of life saving defibrillators in heart failure only had between 9-27% female patients.

Dr Paz Tayal

Improving female academic leadership

We are also beginning to understand that the make up of the scientific team affects how research is done. Heart disease trials that have a senior female academic leading the team recruit more female participants. That is astonishing, and we are trying to understand why that should be the case.

It makes a strong argument for improving female senior academic leadership, however there are currently very few senior female academics in cardiology. We desperately need to make research careers more attractive to female clinicians and scientists and institutions and government must work harder to identify and then address barriers to progression.

The juggle struggle

 I am a full time clinical academic and also a very proud mother to three young children. I’m incredibly passionate about my patients and the research I do for them, which motivates me. But the ‘juggle struggle’ as I call it is immensely challenging. This is the tricky act of balancing being a consultant cardiologist, scientist, grant writer, paper publisher, supervisor, teacher, journal reviewer, and national committee member (the Royal Society, British Cardiovascular Society) with being a mum, wife, daughter, friend, chef, taxi-driver, school rep, costume maker, cake baker, as well as official rememberer of all school events. Can we have everything and do it all? Yes, but just not on the same day!

I strongly believe affordable childcare should be a national infrastructure priority to enable parents to return to the workplace productively if they wish. Employers should continue to respect and value flexible working, for many reasons that extend beyond the benefits to working parents. I also believe we need to be more honest and open about how hard it is, and that that’s ok. The image of this being effortless is not doing anyone justice.

Still a work in progress

In academic medicine as a whole, I think we could do with more truth telling. We only ever really see everyone else’s successes in terms of grants or papers, we never see the inevitable failures behind closed doors. Talent in this game will only get you so far, it’s resilience that will take you to the top. However not all of us are born with steely resilience and it’s a skill to be learnt, just like driving a car.  I’m still a work in progress. But there are things that help. Figure out what empties your stress bucket instead of filling it up. For me, that’s playing with my kids, exercising and reality tv (I did just say we need more honesty, no judgements!). I have an incredible support network of family, friends, colleagues, and mentors. I was selected to be part of the AMS SUSTAIN mentoring programme and the dedicated programme of leadership, coaching, mentoring, presentation, and media training has been invaluable.  I’d encourage everyone at whatever career stage to get a mentor, there are great schemes at the Academy of Medical Sciences and Imperial. Find your tribe and uplift someone in theirs, it makes the world of difference.

Dr Paz (Upasana) Tayal is an MRC Clinician Scientist at the National Heart and Lung Institute and a Consultant Cardiologist specialising in cardiomyopathy and cardiac imaging. She is based at the Cardiovascular Research Centre at the Royal Brompton Campus. 

One comment for “Getting to the Heart of the Matter: Sex Differences in Cardiomyopathy

  1. What a clear thoughtful article. Great read and I am both wiser and more ready to admit failures at the end of it.

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