Dr. Shilpa Kshatriya–Awareness of Heart Disease in Women
February 6th was this year’s Go Red Day when we recognize that heart disease is the leading cause of death for women. About 1 in 3 women die from heart disease. The rates of death from coronary artery disease continue to increase in young women ( < 55 years). However, awareness of the importance of heart disease in women is improving and according to a 2012 American Heart Association National Survey 56% of women were aware that heart disease is the leading cause of death compared to only 30% in 1997.
Women often suffer worse consequences from heart disease compared to men. Among individuals with a history of a heart attack at a young age ( < 50 years) women experience a 2 fold higher mortality rate compared to men. Women also experience higher rates of angina and recurrent hospitalizations. A greater proportion of women die of sudden cardiac death before their arrival at a hospital (52%) contrasted with 42% of men.
Paradoxical sex differences are observed where women have less anatomical obstructive coronary artery disease (CAD), but yet have a higher prevalence of angina. Symptomatic women undergoing coronary angiography have less extensive and severe CAD, despite being older with a greater risk factor burden, compared to men. Women have a more adverse prognosis compared to men despite relatively less CAD. The term “Female Specific Ischemic Heart Disease” is a more appropriate description that CAD and includes heart disease secondary to microvascular dysfunction, plaque erosion and abnormal coronary reactivity which are often seen in women.
About 30% women who present with chest pain, normal coronary angiograms and endothelial dysfunction developed obstructive CAD during a 10 year follow-up, emphasizing the fact that nonobstructive CAD is not a benign prognosis. In the Dallas Heart Study, angina was not related to atherosclerosis measured by Coronary Calcium score but was related to risk factors like obesity, insulin resistance and serum inflammatory markers. 29% women in this study had angina in the absence of atherosclerosis (about 1/3 of women).In treating women with chest pain and nonobstructive disease, therapies should be directed at improving endothelial function, including statins, beta blockers and angiotensin converting enzymes inhibitors. Exercise training improves symptoms. Ranolazine has showed improvement in anginal symptoms in women with ischemia and nonobstructive CAD.
The Framingham risk score underestimates cardiovascular risk in women but the use of the Reynolds Risk Score which also adds high sensitivity C-reactive protein and family history better risk stratifies women. Assessment of a CT Calcium Score also improves risk prediction in women with the presence of any coronary calcium being associated with a 6 fold increased risk of coronary artery disease. The 2011 Effectiveness Based Guidelines for the Prevention of Coronary Artery Disease in Women classifies women into three categories based on risk factors—-high risk, at risk, optimal risk. In addition to traditional risk factors, having risk factors such as poor diet, elevated calcium score, autoimmune diseases like systemic lupus erythematosus or rheumatoid arthritis, pre-eclampsia and gestational diabetes automatically classifies women into the AT RISK category.
Why is mortality due to Acute Coronary Syndrome higher in women? Women are often less aggressively treated and are less likely to receive aspirin, heparin, beta blockers and less likely to undergo timely coronary intervention. They experience higher rates of bleeding after procedures. Women are also less likely to seek rapid and appropriate care when symptoms start, and present to the Emergency Room an average of an hour later than men.
In summary, Ischemic Heart Disease is a more appropriate term to describe the spectrum of CAD in women. Despite lower prevalence, women have higher mortality, hospitalization rates and are more likely to have persistent symptoms. Framingham risk score can underestimate risk. Nonobstructive CAD should be recognized as an entity and is not a benign diagnosis. Future investigation should be tailored to identifying diagnostic and therapeutic strategies to improve outcomes in women.