Detection of subclinical atherosclerosis by electron beam tomography in females with heterozygous familial hypercholesterolaemia.
F amilial hypercholesterolaemia (FH) is a common genetic disorder that affects around 1 in 500 people in its heterozygous form (HeFH). HeFH is associated with an early onset of coronary heart disease (CHD), especially in men. In women the risk of first CHD event is much less than in men, generally , 1% by 40 years of age, 12% by 50 years, 58% by 60 years, and 74% by 70 years of age. In spite of increased cholesterol values, the clinical expression of CHD in HeFH is variable and is also dependent on other risk factors. Currently there is consensus that males with HeFH should be treated early and aggressively with lipid lowering drugs. However, there is some controversy over when females with HeFH should be treated with statins since CHD generally manifests itself 10 years later than in men and there are restrictions to the use of statins in women during their reproductive years. Most importantly, cost effectiveness data on this issue are not available. Current CHD prevention guidelines recommend the use of clinical scores such as the Framingham risk charts in order to predict CHD risk and to guide pharmacological treatment. However, these scores were not developed for HeFH patients, therefore clinicians should rely empirically on plasma lipid concentrations, early CHD family history, and on the presence or absence of other CHD risk factors to institute treatment. The detection of subclinical atherosclerosis could be helpful in determining selected subjects at high risk and therefore candidates for more aggressive and early lipid lowering. 4 Coronary artery calcification (CAC), as determined by electron beam tomography, is a marker of coronary artery plaque burden. Severe CAC—that is, above the 75th centile for the population distribution for age and sex—is associated with a high risk of CHD. A few studies have evaluated the presence of subclinical atherosclerosis by electron beam tomography in FH patients. 6 In these studies the cholesterol–age product, a marker of exposure to the cholesterol burden during lifetime, was associated with the presence of CAC. The objective of our study was to evaluate CAC in asymptomatic female HeFH patients and compare it to normal women. We also evaluated whether the cholesterol– age product correlates with the intensity of CAC in females with and without HeFH.