Why gender matters when it comes to heart disease
Cardiology “I was so surprised to learn during your presentation yesterday that women’s outcomes are worse than men’s following a heart attack.”
When it comes to heart disease, we know that women are not just small men. Yet many of our current diagnostic tests and subsequent treatment decisions are based on cardiac research done on (white, middle-aged) male subjects, or with females represented in statistically insignificant numbers. Cardiovascular disease is not alone, by the way: scientific research has historically focused on men, with two-thirds of all diseases that affect both men and women studied exclusively in men. Here are some important heart-related differences:
Women’s blood vessels are exposed to changing levels of estrogen throughout our lives, first during regular menstrual cycles, then pregnancy, and later during and after menopause as estrogen levels decline with age. Estrogen affects how blood vessels narrow and widen and how they respond to injury, so changes in our estrogen levels can mean changes in the behaviour of blood vessels.
New research from Finland suggests that women’s naturally low iron stores until menopause may actually be a protective factor in our risks for heart disease. Women’s vessels may also be ‘programmed’ for more changes than men’s vessels, which could increase the risk of having problems in the lining of the arteries (endothelium) and the smooth muscles in the walls of the arteries. Women in several studies, including the WISE study, have had evidence of damage to the smooth muscle in the small arteries.
In addition to changing hormone levels of menstruation and menopause, there are several other risk conditions for blood vessel problems that are unique to women, such as pre-eclampsia and other pregnancy complications (a condition that I had while pregnant with my first baby). Learn more at Pregnancy Complications Strongly Linked To Heart Disease.
Being appropriately diagnosed when presenting with cardiac symptoms is the key to being appropriately treated. Yet women (especially younger women) with heart disease are far more likely than men to be misdiagnosed.
Research on cardiac misdiagnoses reported in the New England Journal of Medicine* looked at more than 10,000 heart patients (48% women) who had gone to their hospital Emergency Departments with chest pain or other heart attack symptoms. Women younger than 55 were seven times more likely to be misdiagnosed than men of the same age. The consequences of this were enormous: being sent away from the hospital doubled the chances of dying.
Watch these two panel discussions on “The Heart Of AWoman“ with female cardiologists for more on these gender differences, or this 2-minute video from the Mayo Women’s Heart Clinic about why women’s cardiac diagnoses lag behind men’s.
Carolyn Thomas is a heart attack survivor, patient activist, speaker, and blogger on the west coast of Canada. Her writing on women's heart health issues has been published internationally, including in the British Medical Journal (BMJ). She also serves as a Patient Reviewer for the BMJ for cardiology papers submitted for publication as part of the journal's peer review process.