While cardiovascular disease (CVD), including coronary artery disease (CAD) and stroke, is the leading cause of death in both men and women in the United States, more women die than men each year.1 CAD alone is the primary cause of death among American women, more than from all cancers combined, and accounts for over 300,000 deaths per year.1 While women are most concerned with death due to breast cancer, the mortality risk from CVD greatly exceeds that from breast cancer after age 50 years (Fig. 20-1).2 The detection of heart disease in women presents an important challenge to the clinician. This chapter will review the data on women and heart disease and the value of nuclear myocardial perfusion imaging (MPI) in assessment and prognosis.
Comparison of percentage of deaths related to breast cancer or heart disease and age. (Data from Ref 1.)
THE PROFILE OF WOMEN WITH HEART DISEASE
There are well-recognized differences in the presentation of women and men with heart disease. Although women do experience typical symptoms of CAD, there are gender differences in both how women present with acute coronary syndromes and the symptoms they report. Women have a higher mortality than men, even though they present more commonly with unstable angina vs. ST elevation MI.3–6 Fewer women survive their initial MI than men, with higher 30-day and 1-year mortality rates.7–9 Women are more likely to sustain non-Q-wave and silent MIs and have a higher rate of reinfarction as well as heart failure post-MI.9–11 Often women do not have or do not recognize prodromal symptoms as evidenced by the fact that two thirds of women have fatal MI without recognized symptoms as their initial presentation of CAD.1 CAD is less prevalent in premenopausal women, and its incidence tends to lag 10–15 years behind that of men until approximately the seventh decade of life.1
Women share the major cardiac risk factors of hypertension, diabetes, high cholesterol, smoking, and family history with men, although the relative importance of each risk factor, and the number of risk factors at presentation, differs.11–14 For example, the mortality rate for women without diabetes is half that of men without diabetes, but women with diabetes have an equal mortality as compared to men with diabetes.15 In addition, in women, the presence of metabolic syndrome (increased abdominal girth, hypertension, impaired glucose tolerance, low HDL-C, and high triglycerides) is associated with atherosclerosis and increased cardiovascular events.16
Differences have been demonstrated in referral patterns for women with suspected CAD. The greatest difference in referral rates is in the initial screening for CAD.17,18 Pope et al.19 performed a prospective emergency room study analyzing the ...