Cardiovascular disease (CVD) is the leading cause of death in women. For more than 2 decades, more women have died from CVD compared to men.1 However, for several decades, CVD was regarded as a male disease. Women were underrepresented in cardiovascular clinical trials and comprised <27% of trial participants.2 Only 33% of clinical trials reported sex-specific outcomes.2 These low enrolment numbers resulted in most clinical trials being underpowered to evaluate for gender-specific outcomes. This has had significant implications because for carrying out clinical translation of research in a specific population group, that population group should adequately represented in research study. This has not been the case for women in most major cardiovascular trials. Moreover, a growing body of evidence has suggested that there may be differences in the clinical presentation of CVDs in men and women, in addition to sex differences in terms of impact of cardiovascular risk factors, CVD prevention, and even the pathophysiology of CVD.
The first milestone toward reducing the cardiovascular disparities in women, was the 1985 Report of the Public Health Service Task Force on Women's Health Issues.3 This report highlighted concerns that there was a scarcity of health information available to women, and that women were underrepresented in clinical research. In 1991 the National Institute of Health (NIH), under the direction of Dr Bernadine Healy, established a policy that all NIH-funded trials must include both women and men in studies of conditions that affect both genders. As a result, the majority of studies on women and CVD commenced following this mandate. In 1992, the National Heart, Lung and Blood Institute (NHLBI) conducted a conference on Cardiovascular Health and Disease in Women.4 This conference identified several knowledge gaps affecting ideal cardiovascular health-care delivery in women. The Heart and Estrogen/Progestin Replacement Study (HERS)5 and the Women's Health Initiative (WHI)6 were the next 2 important landmarks in women's health. The WHI was initiated in 1992 and was designed to evaluate the efficacy of hormone replacement therapy for the primary prevention of coronary heart disease (CHD) in postmenopausal women.7 In 1993, the HERS study began enrolment of postmenopausal women with a uterus and with CHD to study the efficacy and safety of estrogen plus progestin therapy for secondary prevention of CHD in women.8 Both studies showed that menopausal hormonal therapy did not reduce the risk of CVD in menopausal women. Rather the risk of myocardial infarction and stroke increased in the healthy women in the WHI study who were on hormone replacement therapy compared with placebo. These 2 studies redirected the clinical focus on implementing standard cardiovascular management strategies in women, rather than focusing on hormonal replacement therapy as the solution for CVD in women. The 2001 Institute of Medicine (IOM) report took sex disparity in CVD to the next level by stating that sex differences in disease and medical research should be explored and implemented in the ...