Comparison in women versus men of composition of atherosclerotic plaques in native coronary arteries and in saphenous veins used as aortocoronary conduits.

OBJECTIVES: This study quantifies and compares the components of atherosclerotic plaques in native coronary arteries and in saphenous vein grafts used for aortocoronary bypass surgery in women versus those in men.
BACKGROUND: Plaque composition has been described in various manifestations of fatal coronary artery disease and after the bypass operation, but no reports have investigated this composition according to gender.
METHODS: A total of 979 5-mm segments of native coronary arteries and 842 5-mm segments of saphenous vein grafts were examined by computerized planimetric technique in 11 women and 11 men who were matched for survival time after the bypass operation.
RESULTS: Comparison of the plaque components revealed that atherosclerotic plaques in women, compared with those in men, contained significantly more cellular fibrous tissue, both in native coronary arteries (mean 38% vs. 4%, p < 0.001) and in saphenous vein grafts (mean 70% vs. 36%, p < 0.05). In contrast, the proportion of dense fibrous tissue was significantly less in the atherosclerotic plaques of women than in those of men, both in native coronary arteries (mean 50% vs. 85%, p < 0.001) and in saphenous vein grafts (mean 25% vs. 57%, p < 0.05).
CONCLUSIONS: Cellular fibrous tissue is often found at an early stage of plaque development, whereas dense fibrous tissue is a major component in later stages. Thus, the plaque composition of the native coronary arteries and saphenous venous conduits differed in men and women, with the plaques of the women appearing younger than those of the men.