Coronary Artery Disease in Women - A Paradox

In the U.S., more than 250,000 women die each year from ischemic heart disease (IHD). Current projections indicate that this will increase with our aging population and epidemics of obesity, metabolic syndrome, and diabetes mellitus.

Notably, IHD is the leading killer of women at all ages, with annual mortality rates affecting greater numbers of younger and older women than breast cancer. Additionally, resource consumption patterns in women are characterized by more frequent angina diagnosis, more office visits, more avoidable hospitalizations, higher myocardial infarction (MI) mortality, and higher rates of heart failure as compared with men.

Clear gender differences in the presentation, pathophysiology, and treatment of ischemic heart disease underscore the need for more study of women.

Three paradoxes are evident with regard to gender differences in IHD.

First, women have a higher prevalence of angina (chest pain or discomfort caused when the heart muscle doesn’t get enough oxygen-rich blood) compared to men, yet have an overall lower prevalence of atherosclerosis and obstructive coronary artery disease (CAD).

Second, symptomatic women undergoing coronary angiography have less extensive and severe CAD, despite being older with a greater risk factor burden, compared to men.

Third, despite relatively less CAD, women have a more adverse prognosis compared to men.

These three paradoxical findings suggest an alternative, gender-specific pathophysiology for IHD in women, given our traditional understanding that the majority of angina and adverse cardiovascular outcomes stem from obstructive CAD.

Advanced cardiac imaging can be used to further our understanding of the pathophysiology of these paradoxes of ischemic heart disease in women. Identification of nonobstructive CAD, MCD, and abnormal nonsegmental perfusion abnormalities are associated with an elevated risk of adverse events similar to obstructive CAD.

A new study that followed nearly 70,000 women for two decades concluded that three-quarters of heart attacks in young women could be prevented if women closely followed six healthy lifestyle practices.

Healthy habits were defined as:

1. Not smoking
2. A normal body mass index
3. Physical activity of at least 2.5 hours per week
4. Watching seven or fewer hours of television a week
5. Consumption of a maximum of one alcoholic drink per day on average
6. A diet in the top 40 percent of a measure of diet quality based on the Harvard School of Public Health healthy eating plate.

During 20 years of follow-up, 456 women had heart attacks and 31,691 women were diagnosed with one or more cardiovascular disease risk factors, including Type 2 diabetes, high blood pressure or high levels of blood cholesterol.

The average age of women in the study was 37.1 years at the outset; the average age of a heart disease diagnosis was 50.3, and the average age for diagnosis with a risk factor for heart disease was 46.8.

Researchers found that women who adhered to all six healthy lifestyle practices had a 92 percent lower risk of heart attack and a 66 percent lower risk of developing a risk factor for heart disease.

This lower risk would mean three-quarters of heart attacks and nearly half of all risk factors in younger women may have been prevented if all of the women had adhered to all six healthy lifestyle factors, the authors said.

For women who were diagnosed with a risk factor, adherence to at least four of the healthy lifestyle factors was associated with a significantly lower risk of going on to develop heart disease when compared to those who did not follow any of the healthy lifestyle practices.

Independently, not smoking, adequate physical activity, better diet, and lower BMI were each associated with a lower risk for heart disease.

Women who consumed moderate amounts of alcohol — approximately one drink per day on average — saw the lowest risk compared to those who did not drink at all and those who drank more.