Female sex: a protective role in suspected myocardial ischemia

Sex-related differences in the angiographic results of 14,500 cases referred for suspected coronary artery disease

OBJECTIVE

To investigate sex differences of angiographic results in patients undergoing coronary angiography for suspected coronary artery disease (CAD).

METHODS

We retrospectively assessed the coronary angiograms of 2840 women and 11,610 men from 1984 to 2003. We examined sex differences regarding the extent and topography of significant stenoses (SS) (i.e. > or =50% of the luminal diameter), the age of presentation, and the variation of the annual frequency of the angiographic findings across the study period.

RESULTS

SS were recorded in 1817 women and 9984 men (64 vs. 86%, P<0.001). Women were more likely to present with nonsignificant stenoses (i.e. <50% of the luminal diameter) or angiographically normal coronaries (P<0.001). In patients with SS, women had a higher chance to present with one-vessel (P<0.001) or peripheral branches (P<0.05) disease, whereas men were more likely to have two-vessel disease (P<0.005). Compared with men, women were less likely to exhibit SS in the right coronary artery (P<0.001), left circumflex (P<0.01), intermediate artery (P<0.01) and first obtuse marginal branch (P<0.01). No significant sex differences were recorded in the frequency of SS in the left anterior descending artery. In patients aged from 31 to 60 years, SS were more common in men, whereas in patients 61-80 years of age SS were more common in women. The annual frequency of SS in women gradually increased throughout the study period.

CONCLUSION

SS were less common in women, were found later in life, and were less likely to involve the right coronary artery, left circumflex, intermediate artery and first obtuse marginal branch than in men.

Effects of sex hormone levels on aortic vascular reactivity and variables associated with the metabolic syndrome in sucrose-fed female rats

We studied the effect of varying levels of sex hormones, induced by ovariectomy and administration of testosterone or estradiol, on aortic reactivity in female rats with metabolic syndrome (MS) induced by a sucrose diet. Vasoreactivity of aortic rings, blood pressure, intra-abdominal fat, serum triglycerides, nitrates and nitrites, and TBARS were evaluated. Intact MS and ovariectomized MS had higher BP than intact control (C) and ovariectomized C, respectively; estradiol administration decreased BP in ovariectomized MS but not in ovariectomized C. Triglycerides and fat were both higher in MS. Triglycerides were not modified by surgery or hormone treatment, but ovariectomy increased fat. When ovariectomy was combined with hormones, however, fat was reduced to the level of intact rats. Ovariectomy decreased, but hormones increased, serum nitrates and nitrites. Vasoconstriction was larger in intact MS and ovariectomized MS + testosterone aortas than in intact C and ovariectomized C + testosterone, respectively. Vasodilation was reduced in intact MS and ovariectomized MS + testosterone compared with intact C, ovariectomized C + testosterone, ovariectomized MS, and ovariectomized MS + estradiol. The results suggest endothelial dysfunction in intact MS and ovariectomized MS + testosterone, but protection by ovariectomy + estradiol in MS due to hormones. Indomethacin reduced all contractions, but the effect was greater in estradiol-treated rats. l-NAME increased contractility, more in the ovariectomized C and MS groups and less in the estradiol-treated groups.