Comparison of Prognostic Usefulness of Coronary Artery Calcium in Men Versus Women (Results from a Meta- and Pooled Analysis Estimating All-Cause Mortality and Coronary Heart Disease Death or Myocardial Infarction)

Abstract

Women with coronary heart disease (CHD) have higher mortality compared with men. Atherosclerotic imaging risk markers are associated with higher mortality and relative risk of CHD events in women compared with men. However, data on the predictive accuracy of coronary artery calcium (CAC) in women are scarce. We performed a systematic review of the published literature from 2003 to 2006 on the prognostic value of CAC in women and men. Two investigators reviewed Medline for prospective registries on annual rates of CHD death or myocardial infarction (MI) by CAC results. Three studies in 6,481 women and 13,697 men reported results by gender. We also analyzed 2 observational registries for annual all-cause death rates by CAC scores in women (n = 17,779) and men (n = 17,850). Summary relative risk ratios and 95% confidence intervals were calculated using a random effects model. For all-cause mortality, rates were 0.1% to 1.6% per year for women and 0.1% to 2.6% for men with CAC scores from 0 to 10 to > or =1,000, respectively (p <0.0001). For CHD death or MI, annual rates were 0.2% to 1.3% in women and 0.3% to 2.4% for men with low- to high-risk CAC scores. For women with a CAC score of 0, annual CHD death or MI rates were 0.16%, similar to that of men (p = 0.55). Summary relative risk ratios increased 4.9-fold (p = 0.006), 5.5-fold (p = 0.002), and 8.7-fold (p <0.0001) for mild-, moderate-, and high-risk CAC scores, respectively. A comparative analysis of gender differences showed no significant differences between women and men for mild- to high-risk CAC scores (p = 0.66), suggesting an equivalent ability to risk stratify by gender. In conclusion, this meta- and pooled analysis revealed that CAC screening is equally accurate in stratifying risk in women and men.