Gender Differences in the Epidemiology, Clinical Presentation, Prevention, and Prognosis of Acute Coronary Syndromes

Abstract

In this issue of Angiology, Shehab et al describe gender differences in cardiovascular (CV) risk factors, clinical manifestations, treatment, and short-term prognosis in patients admitted with acute coronary syndrome (ACS). Women were older and had higher prevalence of hypertension, dyslipidemia, and diabetes. Obesity was more frequent in women, while smoking was more frequent in men. In-hospital mortality and complications were greater in women than in men. There are several points of interest in this study. In the general population, coronary heart disease (CHD) affects men more than women. For example, in the United States its prevalence was 37.4% in men and 35.0% in women, in 2008. Different distribution of various CV risk factors was suggested between men and women with CHD. Epidemiological studies, including the Framingham study, showed that CHD presents at an earlier age in men than in women. The INTERHEART study included 12 461 patients with a first myocardial infarction (MI) and 14 637 ageand sexmatched controls from 52 countries. Among these, 6787 were women. Women with MI were older than men (median age 65 vs 56 years, P 80% after the adjustment for 9 modifiable CV risk predictors. These included smoking, exercise, alcohol abuse, fruit and vegetable consumption, hypertension, diabetes, abdominal obesity, psychosocial factors, and increased apolipoprotein (apo) B/apoA1 ratio. This finding implied that the earlier age of MI in men reflects the higher levels of several risk factors, such as smoking, which men possess in younger ages. Therefore, the higher prevalence of smoking in men in the Shehab et al study could at least in part explain the gender-related difference in the age of ACS occurrence. Younger women benefit from the protective effects of endogenous estrogens, including estradiol. Estradiol inhibits many processes involved in age-related vascular remodeling. These include vascular smooth muscle cell proliferation and endothelial dysfunction. Furthermore, estradiol lowers cholesterol levels and improves the vascular tone. On the other hand, menopause has been recognized as a risk factor for CV disease due to the reduction in endogenous estrogen. In this context, early loss of endogenous estrogens in young oophorectomized women may increase CV risk. The role of hormone replacement therapy (HRT) in CV disease prevention in postmenopausal women is debated. Despite promising data from observational studies regarding decreased risk of CV events in women on HRT, no such protective effect was documented by randomized clinical trials. The study by Shehab et al is consistent with numerous studies, showing that among patients with ACS, hypertension, diabetes, and hypercholesterolemia are more prevalent in women than in men. On the other hand, men smoke more. In the INTERHEART study, the predictive value for MI in hypertension, diabetes, physical inactivity, and alcohol abuse was higher in women than in men. In contrast, smoking better predicted MI in men. Interestingly, the presence of smoking and diabetes increased the risk of CHD more in women than in men. This relationship appears to be greater in younger women (<55 years). In Shehab et al’s study, the prevalence of obesity was higher in women with ACS than in men. Obesity often coexists with various cardiometabolic risk factors in metabolic syndrome (MetS). Except for abdominal obesity, MetS components include high blood pressure, dysglycemia together with hyperinsulinemia as well as raised triglyceride (TG) and low high-density lipoprotein cholesterol (HDL-C) levels. The MetS independently predicts ACS. Although metabolic abnormalities were more prevalent in women than in men, according to Shehab et al the majority of MetS patients were men. This finding is more interesting considering the higher age of women. It was suggested that the prevalence of MetS increases with age. Especially for women, this risk was