Achilles tendon ultrasonography in the clinical screening of familial hypercholesterolaemia - a cross-sectional analysis

BACKGROUND AND AIMS

People with familial hypercholesterolaemia are 13 times more likely to develop cardiovascular disease than the general population. However, familial hypercholesterolaemia remains largely underdiagnosed. Tendon xanthoma is a specific clinical feature of familial hypercholesterolaemia and its presence alone implies a probable diagnosis of familial hypercholesterolaemia according to the Dutch Lipid Clinic Network Score (DLCNS). The aim of the study was to determine whether ultrasound detects more Achilles tendon xanthomas (ATX) than clinical examination.

METHODS

We recruited 100 consecutive patients with LDL-C ≥4 mmol/l. Achilles tendons were evaluated through clinical examination by trained physicians and sonographic examination by another physician blind to the results of clinical examination. Blind second readings of ultrasound images were performed by an expert in musculoskeletal ultrasound. We compared the proportion of patients with ATX detected by either clinical examination or ultrasound and the proportion of patients with a probable/definite familial hypercholesterolaemia diagnosis on the DLCNS before and after ultrasound.

RESULTS

Mean (SD) age was 47 (12) years; mean highest LDL-C was 6.57 mmol/l (2.2). ATX were detected in 23% of patients by clinical examination and in 60% by ultrasound. In consequence, 43% had a probable/definite diagnosis of familial hypercholesterolaemia on the DLCNS using clinical examination compared with 72% when ultrasound was used.

CONCLUSION

Compared to clinical examination, ultrasound examination of the Achilles tendon substantially improves the detection of ATX and may help to better identify patients with familial hypercholesterolaemia who are at high risk for premature cardiovascular disease.

High-Sensitivity C-Reactive Protein and Carotid Intima Media Thickness as Markers of Subclinical Inflammation and Atherosclerosis in Pediatric Patients with Hypercholesterolemia

Hypercholesterolemia is a major cause of atherosclerosis development and premature cardiovascular disease (CVD). It leads to inflammation, which further accelerates atherosclerosis progression. Familial hypercholesterolemia (FH) is an autosomal dominant disorder characterized by elevated serum LDL-c from birth, due to a disease-causing variant in one of the causative genes (LDLR, APOB, PCSK9). In polygenic hypercholesterolemia (PH), the disease-causing genetic variant is absent; it is likely the cumulative result of multiple single nucleotide polymorphisms in LDL metabolism-related genes and other factors, such as lifestyle and environment. In high risk groups, such as patients with FH, an effective primary prevention of CVD must begin in childhood. High-sensitivity C-reactive protein (hsCRP) and carotid intima media thickness (cIMT) are two potential minimally invasive correlates of inflammation and subclinical atherosclerosis progression. hsCRP and cIMT have been shown to be significantly increased in patients with FH and PH relative to healthy controls, with some studies yielding conflicting results. In this review, we aim to summarize current knowledge and recent findings regarding the applicability of hsCRP and cIMT as markers of low-grade inflammation and subclinical atherosclerosis, focusing especially on children and adolescents with hypercholesterolemia.

Atherosclerotic cardiovascular disease risk assessment in familial hypercholesterolemia: does one size fit all?

PURPOSE OF REVIEW

Familial hypercholesterolemia is a frequent genetic disease associated with lifelong elevation of LDL-cholesterol and premature atherosclerotic cardiovascular disease (ASCVD). Statins are the cornerstone of treatment. However, with the introduction of novel LDL-cholesterol-lowering therapies, it is necessary to identify familial hypercholesterolemia patients presenting a significantly high residual ASCVD risk. The aim of this review is to provide an update on the recent literature concerning cardiovascular risk stratification including the role of coronary imaging.

RECENT FINDINGS

Several factors have shown to be independent predictors of ASCVD in familial hypercholesterolemia. These include clinical scores with cardiovascular risk factors, coronary imaging and novel protein biomarkers. However, the recent introduction of the SAFEHEART risk-equation (SAFEHEART-RE) could allow a more accurate ASCVD risk prediction in familial hypercholesterolemia.

SUMMARY

This article highlights the SAFEHEART-RE as a model to predict incident ASCVD in familial hypercholesterolemia. This equation is a simple and widely applicable tool for use in every clinical setting. Furthermore, coronary atherosclerosis assessed by coronary computed-tomographic angiography (coronary-CTA) is independently associated to the cardiovascular risk estimated according to the SAFEHEART-RE. This equation, as well as coronary-CTA and new biomarkers, could increase individual ASCVD risk stratification and could improve the efficiency and the use of new lipid-lowering therapies in familial hypercholesterolemia.

Cardiac computed tomography imaging in familial hypercholesterolaemia: implications for therapy and clinical trials

PURPOSE OF REVIEW

The purpose of the present review is to summarize the potential clinical applications of computed tomographic angiography (CTA) in familial hypercholesterolemia so far and recent advances of CTA research in other high-risk patients.

RECENT FINDINGS

Long-term, aggressively statin-treated, asymptomatic familial hypercholesterolemia patients may still have dramatic coronary artery disease (CAD). A clear association between the presence and the extent of nonobstructive CAD and all-cause mortality was found in the COronary CT Angiography EvaluatioN For Clinical Outcomes: An InteRnational Multicenter registry. Notably, baseline statin therapy was associated with a significantly lower mortality for individuals with atherosclerotic plaque on CTA, but not for individuals with normal coronary arteries.

SUMMARY

CTA imaging has made clear that an increased plaque burden can be present even among asymptomatic, long-term aggressively statin-treated familial hypercholesterolemia patients. In the COronary CT Angiography EvaluatioN For Clinical Outcomes: An InteRnational Multicenter registry, nonobstructive CAD predicted all-cause mortality and statin treatment improved the life span of persons with nonobstructive CAD. Clinical trials with CTA are required to develop and test identification of CAD and personalized treatment strategies for familial hypercholesterolemia.

Multiple tendon xanthomas in patient with heterozygous familial hypercholesterolaemia: sonographic and MRI findings

Tendon xanthomas are a component of familial hypercholesterolaemia, which is a hereditary disease and characterised by elevated low-density lipo protein cholesterol plasma levels and premature coronary artery disease. Tendon xanthomas are diagnostic for heterozygous familial hypercholesterolaemia (HFH) and they mostly occur in Achilles tendon. Sonography and MRI are superior to clinical assessment and are useful in detecting tendon xanthomas. In this report, we present ultrasonographic and MRI findings of multiple tendon xanthomas in a case of HFH.

Displacement and strain estimation for evaluation of arterial wall stiffness using a familial hypercholesterolemia swine model of atherosclerosis

PURPOSE

To track variations in the deformation of the arterial wall noninvasively by estimating the accumulated displacement and strain over a cardiac cycle may provide useful indicators of vascular health.

METHODS

In this paper, we propose an approach to track a region of interest (ROI) locally and estimate arterial stiffness variation in a familial hypercholesterolemic swine model of spontaneous atherosclerosis that allows for systematic and reproducible study of progression of the disease mechanism.

RESULTS

Strain and displacement indices may be derived from the variations of the accumulated displacement and accumulated strain (obtained from the gradient of the accumulated displacement) over a cardiac cycle to predict not only the likelihood of developing vascular diseases, but also the sites where they may occur. Currently, an ROI thickness value of less than one mm within the arterial wall is necessary for the axial accumulated displacement and strain to obtain reproducible estimates.

CONCLUSIONS

Accumulated axial displacement and strain estimation on the artery wall shown in this paper indicate the repeatability of these measurements over several cardiac cycles and over five familial hypercholesterolemic swine. Our results also demonstrate the need for a small region of interest within the arterial walls for accurate and robust estimates of arterial function.

Ultrasound markers that describe plaques are more sensitive than mean intima-media thickness in patients with familial hypercholesterolemia

A widely adopted ultrasound surrogate marker for predicting cardiovascular risk is mean intima-medial thickness (mean-IMT). There are, however, certain limitations to this methodology. We compared the severity of carotid atherosclerosis in adult patients with high cardiovascular risk (patients with familial hypercholesterolemia [FH] and without previous statin treatment) and in their adult FH-free first-degree relatives using not only mean-IMT, but also maximum-IMT, plaque number, plaque score and percent area stenosis. Mean-IMT has not differed in both groups (0.64 ± 0.18 mm vs. 0.58 ± 0.13 mm in the control group, p = 0.349). Maximum-IMT (0.99 ± 0.35 vs. 0.76 ± 0.19, p = 0.0057), plaque number (3 ± 3 vs. 1 ± 2, p = 0.0009), plaque score (5.14 ± 4.97 mm vs. 1.58 ± 3.09 mm, p = 0.0009) and percent area stenosis (38% ± 22% vs. 12% ± 20%, p = 0.0004) were significantly higher for FH patients than for their relatives. We have demonstrated that plaque number, plaque score and percent area stenosis markers were more sensitive than mean-IMT for cardiovascular risk estimation in patients with familial hypercholesterolemia.

Mutations in the LDL receptor gene in four Chinese homozygous familial hypercholesterolemia phenotype patients

BACKGROUND AND AIMS

Familial hypercholesterolemia (FH) is an autosomal dominant disorder of lipoprotein metabolism caused by mutations in the low-density lipoprotein receptor (LDL-R) gene, leading to elevated levels of cholesterol and an increased risk of coronary heart disease. In this article, from four homozygous FH phenotype probands we identified disease causing mutations and analyzed the relationship between genotype and phenotype.

METHODS AND RESULTS

DNA sequencing identified five LDL-R point mutations in four unrelated families. We found a novel homozygous mutation (C210R), a homozygous mutation at W462X, a compound heterozygous mutation of C122Y and T383I, and a G>A intron 3 splice site homozygous mutation. The functional alteration caused by the novel C210R mutation was confirmed by FACS analysis. Four probands have high low-density lipoprotein cholesterol (LDL-C) levels, ranging from 14.65 to 27.66 mmol/L. Their heterozygous parents had relatively low levels. B-mode ultrasound supplemented by Doppler was used to examine aortic/mitral valve structural alterations and carotid intima-media thickness (ITM) in all probands. The ITM values were between 1.2 and 2.3mm, much higher than the normal value of <0.8mm.

CONCLUSION

Our data demonstrated that all the probands were associated with severe hypercholesterolemia, thick carotid IMT and a low CFVR (coronary flow velocity reserve) value. The novel mutation (C120Y) is a disease causing mutation.

Non-invasive detection of aortic and coronary atherosclerosis in homozygous familial hypercholesterolemia by 64 slice multi-detector row computed tomography angiography

Homozygous familial hypercholesterolemia (HoFH) is a rare disorder characterized by the early onset of atherosclerosis, often at the ostia of coronary arteries. In this study we document for the first time that aortic and coronary atherosclerosis can be detected using 64 slice multiple detector row computed tomographic coronary angiography (CTCA). We studied five HoFH patients (three females, two males, mean age 19.8+/-2.9 years, age range 15-23 years, with a mean low density lipoprotein (LDL) cholesterol 618+/-211 mg/dL) using 64 slice CTCA. None of the patients showed evidence of ischemia with standard exercise testing. Calcified and mixed atherosclerotic plaques adjacent to or compromising the coronary artery ostia were found in all study subjects. Coronary plaques causing significant obstruction were found in one patient, who had previously undergone coronary artery bypass surgery and aortic valve replacement. Two other patients were noted to have non-obstructive calcified, mixed and non-calcified coronary artery plaques. Our data suggest that CTCA could be a useful non-invasive method for detection of early aortic and coronary atherosclerosis specifically affecting the coronary ostia in HoFH subjects.

Combined cardiohepatic transplantation due to severe heterozygous familiar hypercholesteremia type II: first case in Argentina--a case report

Heterozygous familial hypercholesteremia type II is a recessive autonomic disease with a population incidence <or=1:500. It develops as a consequence of a mutation in the LDLR gene. Patients suffer extremely high LDL and VLDL cholesterol values, dying from coronary compromise at early ages. As cholesterol synthesis is an hepatic process, and as there is a lack of gene therapy, hepatic transplantation is the only therapeutic option in cases refractory to medical treatment. In this report, we have described the first case of combined cardiohepatic transplantation in Argentina, which was performed in a male patient with severe aortic stenosis and terminal ischemic cardiopathy secondary to severe familial hypercholesteremia type II.

Measurement of the reflectivity of the intima-medial layer of the common carotid artery improves the discriminatory value of intima-medial thickness measurement as a predictor of risk of atherosclerotic disease

Our aim was to assess the predictive value of a measurement of intima-medial layer (IML) reflectivity in the differentiation of pathological from physiological increases in intima-medial thickness (IMT). Both common carotid arteries (CCA) of familial hypercholesterolemia (FH) patients and age- and sex-matched controls (no cardiovascular risk factors) were imaged using a 10- to 15-MHz linear array transducer (n = 30). Images of the CCA far wall were analyzed in the IMT "plug-in" of "HDI Lab." The IML reflectivity, averaged over an 8- to 12-mm length of arterial wall, was expressed as a ratio of reflectivity at a point 0.21-mm deep to the intima-medial interface divided by the reflectivity at the intima-medial interface, termed the intima-medial reflectivity index (IMRI). The risk of atherosclerosis was assessed in terms of IMT alone and IMT coupled with IMRI. Defining high risk of atherosclerosis in FH, in terms of both IMT alone and IMT coupled with IMRI, produced an appropriate, when compared with cholesterol-years score, statistically significant stratification (p < 0.01 and p < 0.005). Analysis of the low-risk subjects revealed a tendency to define a subject as "high risk" based on a physiological increase in IMT, but when IMRI is included in the assessment, all controls are correctly identified as low risk. This method of quantifying the reflectivity of the IML improved the discriminatory performance of IMT increase as an indicator of atherosclerotic risk by enabling a smaller, therefore earlier, increase in IMT to be considered pathologic when accompanied by an increase in IMRI.

Noninvasive detection of coronary atherosclerotic plaque by multidetector row computed tomography

BACKGROUND

Coronary artery disease continues to be one of the leading causes of death and disability around the globe, challenging the efficacy of currently applied schemes to predict the risk for future coronary events. In fact, algorithms such as the Framingham risk score that are based on traditional risk factors like hypertension and dyslipidemia are not very sensitive, leaving a majority of the population at intermediate risk.

METHODS

Advances in multidetector computed tomography (MDCT) technology with submillimeter slice collimation (approximately 0.6 mm) and high temporal resolution now permit contrast-enhanced imaging of the coronary artery lumen and wall in a single breath hold. The current generation of MDCT provided in-plane resolution of 0.5 mm and a temporal resolution of 210 ms. The simultaneous acquisition of 16/64 parallel cross-sections reduces image acquisition time to about 10-20s using 60-80 ml of contrast agents to opacify the coronary artery lumen. CT imaging for coronary calcification is an established method with low radiation exposure. The amount of calcification is expressed as an Agatston Score (AS).

RESULTS

The presence and amount of coronary calcification significantly increases the relative risk for future coronary events, independent from traditional risk factors (risk ratio 8.7 [95% Cl, 2.7-28.1]). Especially, individuals with a high AS (>400) who are at intermediate 10-y Framingham event risk may benefit from this additional risk stratification. However, calcification is rarely present in children and adolescents. However, there is a growing body of evidence suggesting that contrast-enhanced MDCT can detect both calcified and noncalcified plaques with high sensitivity and specificity for the detection of plaques > 0.5 mm when compared to intravascular ultrasound. Moreover, initial data suggest that plaque characteristics such as plaque area, volume, quantify and coronary plaque remodeling index can be quantified in good agreement with IVUS. The composition of noncalcified plaque may be further stratified into predominantly fibrous or lipid-rich plaque. Noncalcified plaque may be present already in children and adolescents with multiple risk factors.

CONCLUSION

The available data indicate that high resolution MDCT can reliably detect, quantify and characterize calcified and noncalcified coronary atherosclerotic plaque. With MDCT, we now have a unique opportunity to study the natural history and response to therapy of noncalcified coronary plaques, which may be already present in obese children or children with multiple risk factors.

Data density curves of B-mode ultrasound arterial wall thickness measurements in unaffected control and at-risk populations

AIM

Atherosclerosis is a slow disease process of arterial walls with onset decades prior to its clinical manifestations. Lifelong follow-up data may help to identify and understand the pathophysiology of this process. These longitudinal data are scarce. Using a standardized imaging and image analysis protocol, we acquired cross-sectional data of carotid and femoral arterial wall segments in populations at different cardiovascular disease risk.

METHODS

B-mode ultrasound intima-media thickness (IMT) data of carotid and femoral arteries were acquired in individuals at high cardiovascular disease risk: 44 young adolescents with familial hypercholesterolemia (FH), 248 adult FH patients and 184 patients with coronary artery disease (CAD), as well as in disease free unaffected individuals, 44 young adolescents, 26 middle-aged adults and 48 senior adults.

RESULTS

Per patient combined average IMT (SD) and % of lesions in the high risk populations were 0.55 (0.05) mm, 0.1%, 0.86 (0.18) mm, 15%, and 0.9 (0.18) mm, 18%, respectively. In the unaffected groups these values were 0.53 (0.03) mm, 0%, 0.59 (0.07) mm, 0%, and 0.77 (0.12) mm, 8%. Of all arterial segments, the far wall of the common femoral artery (CFA) of the FH patients exhibited the highest absolute IMT (1.12 [0.61] mm), the most rapid estimated IMT increase since adolescence (+0.58 mm) and the highest percentage of lesions (39% of CFA measurements).

CONCLUSIONS

Regardless of location, carotid and femoral arterial walls increase in thickness with age and cardiovascular disease risk. This increase in thickness and prevalence of lesions is not similarly distributed among anatomical segments. The strong preponderance in arterial wall segments with the highest estimated atherosclerosis progression indicates the existence of a threshold value beyond which plaque formation is greatly increased. In the set of arterial locations we studied, this process might be best represented by the far wall of the CFA.

The use of Achilles tendon sonography to distinguish familial hypercholesterolemia from other genetic dyslipidemias

OBJECTIVE

Achilles tendon (AT) xanthomas, specific for familial hypercholesterolemia (FH), may be clinically undetectable. We assessed the usefulness of AT sonography in the diagnosis of FH.

METHODS AND RESULTS

Sonographic AT characteristics were evaluated in 127 subjects with FH (81 genetically ascertained), 84 familial combined hyperlipidemia, 79 polygenic hypercholesterolemia, and 88 normolipidemic controls. Abnormal echostructure (sonographic xanthoma) was noted only in FH. AT thickness was higher (P<0.001) in FH men and women compared with all of the other groups and, in FH mutation carriers but not in others, correlated positively with low-density lipoprotein cholesterol (r=0.345; P<0.001) and negatively with high-density lipoprotein cholesterol (r=-0.265, P=0.015). Thickness thresholds for the diagnosis of FH with specificity >80%, as were derived from receiver operating curves, were 5.3 and 5.7 mm in men < and >45 years, and 4.8 and 4.9 mm in women < and >50 years, respectively. In FH mutation carriers, sonographic findings increased the clinical diagnosis of xanthomas from 35 (43%) to 55 (68%). Using thresholds in validation sets of 70 genetically identified FH and 54 dyslipidemic non-FH correctly classified 80% and 88%, respectively.

CONCLUSIONS

Sonographic AT characteristics are normal in non-FH dyslipidemias. Identification of suspected FH by ultrasound using sex- and age-specific AT thickness thresholds is recommended.

[The pathological changes of abdominal and peripheral arteries in familial hypercholesterolemia--the result of high-resolution color Doppler ultrasonography]

OBJECTIVE

To explore changes of abdominal and peripheral arteries in familial hypercholesterolemia (FH) patients with definite etiopathogenesis by high-resolution color Doppler ultrasound; to identify the arteriosclerotic progression of FH patients and offer the valuable foundation for clinic treatment.

METHODS

Observe the interior-media thickness (IMT), stenotic degree and hemodynamics change of arteries by ultrasonography in six children in five family constellations (index case) and six normal controls.

RESULTS

There was significant difference between FH and control group in IMT of the posterior wall in left external carotid artery (origination), right common carotid artery (approaching piece) and IMT of the anterior and posterior wall right common carotid artery (intermediate piece) (P = 0.015). Significant thickening of IMT was not observed in vertebral arteries, subclavicular arteries, abdominal aorta, renal arteries, iliac arteries and popliteal arteries both in FH and control group.

CONCLUSION

The arteriosclerotic aggravation of FH patients could not be revealed by the level of the blood fat, but could be revealed correctly by ultrasonography. It is possible to provide significant foundation for individualized treatment of FH patients by regular non-invasive ultrasonography.

Measurement of arterial wall thickness as a surrogate marker for atherosclerosis

Large observational studies and atherosclerosis regression trials of lipid-modifying pharmacotherapy have established that intima-media thickness of the carotid and femoral arteries, as measured noninvasively by B-mode ultrasound, is a valid surrogate marker for the progression of atherosclerotic disease. To exploit fully the potential of ultrasound imaging in atherosclerosis research, standardized and strictly implemented imaging protocols should be used in both observational studies and applied clinical research. This article describes such a protocol developed at the Academic Medical Center of the University of Amsterdam, the Netherlands. Results are presented from a study that estimated atherosclerosis progression from childhood into old age by measuring intima-media thickness in subjects with familial hypercholesterolemia compared with healthy controls.

Effects of atorvastatin and simvastatin on low-density lipoprotein subfraction profile, low-density lipoprotein oxidizability, and antibodies to oxidized low-density lipoprotein in relation to carotid intima media thickness in familial hypercholesterolemia

BACKGROUND

Little is known about the effects of statins on the quality of circulating low-density lipoprotein (LDL) in relation to atherosclerosis progression.

METHODS

In a double-blind, randomized trial of 325 patients with familial hypercholesterolemia (FH), we assessed the effects of high-dose atorvastatin (80 mg) and conventional-dose simvastatin (40 mg) on LDL subfraction profile (n = 289), LDL oxidizability (n = 121), and circulating autoantibodies to oxidized LDL (n = 220). Progression of atherosclerosis was measured by carotid intima media thickness (IMT) (n = 325).

RESULTS

At baseline, the patients showed an intermediate LDL subfraction profile composed of three LDL subfractions (LDL1, LDL2, LDL3), with LDL2 as the predominant subfraction. A strong negative correlation was found between plasma triglycerides and the LDL subfraction profile (r = -.64, p = .000). Both plasma levels of triglycerides and small dense LDL3 correlated weakly with baseline IMT (r = .11, p = .04 and r = .15, p = .01, respectively; n = 289). No association was found between baseline IMT and oxidation parameters or circulating antibodies to oxidized LDL. Atorvastatin reduced triglycerides, LDL cholesterol, and all LDL subfractions to a greater extent than did simvastatin and led to regression of carotid IMT. However, LDL subfraction pattern and plasma levels of autoantibodies to oxidized LDL remained unchanged in both treatment groups, and LDL oxidizability increased minimally to a similar extent in both groups. Significant treatment differences were found for the rate of in vitro oxidation of LDL and the amount of dienes formed during in vitro oxidation of LDL, which both decreased more following atorvastatin than after simvastatin.

CONCLUSION

Change of IMT after statin treatment was associated with baseline IMT (r = .41), LDL cholesterol (r = -.20), and the amount of dienes formed during in vitro oxidation of LOL (r = .28) but not with plasma levels of antibodies to oxidized LDL, in vitro LDL oxidizability, and LDL subfraction profile.

Arterial intima-media thickness in children heterozygous for familial hypercholesterolaemia

Patients with familial hypercholesterolaemia have severe coronary-artery disease early in adult life. Whether lipid-lowering treatment should be started in childhood remains to be established. We therefore assessed 201 children heterozygous for familial hypercholesterolaemia and 80 unaffected siblings (both age ranges 8-18 years) with B-mode ultrasound to measure carotid wall intima-media thickness. Mean combined carotid intima-media thickness of heterozygotes was significantly greater than that of unaffected siblings (0.494 mm [SD 0.051] vs 0.472 [SD 0.049], p=0.002). A significant deviation in intima-media thickness was noted from age 12 years in children with familial hypercholesterolaemia. Findings on multivariate analysis showed LDL cholesterol, age, and sex to be strong and independent predictors of intima-media thickness. Since raised LDL cholesterol concentrations can be lowered efficiently, clinical studies are needed to investigate long-term safety and effectiveness of statin treatment in children with familial hypercholesterolaemia.

Measurement of intima-media thickness of common carotid arteries using ultrasound in patients with familial and non-familial hypercholesterolaemia and correlation of intima-media thickness to obesity

Ultrasonographic measurements of the intima-media thickness (IMT) of common carotid arteries (CCA) were taken in 50 patients with familial hypercholesterolaemia (FH) and 57 patients with non-familial hypercholesterolemia (NFH). The lipid profile, body mass index (BMI) and waist-hip ratio (WHR) of each patient were recorded. In FH patients, the IMT was significantly higher in overweight and elevated WHR subgroups compared to the normal with significant correlations between BMI and WHR to the IMT. In NFH patients, the IMT was significantly higher in the elevated WHR compared to the normal subgroup but the correlations between either BMI or WHR to IMT were insignificant. These suggest that the environmentally modified anthropometric indices may have an effect on atherosclerosis in genetically determined hypercholesterolaemia in FH patients.

Increased carotid artery intima-media thickness is associated with a novel mutation of low-density lipoprotein receptor independently of major cardiovascular risk factors

The current study sought to investigate the role of low-density lipoprotein receptor (LDLr) mutations in assessing the risk profile of familial hypercholesterolemia (FH) patients, independently of major cardiovascular risk factors. FH due to LDLr mutations is associated with premature atherosclerosis. The variable clinical severity of the disease in heterozygotes has been related to cholesterol levels and the coexistence of other cardiovascular risk factors, but the independent role of different LDLr mutations is still unclear. cDNA of LDL gene was sequenced in 102 patients with clinical features of heterozygous FH. Carotid artery intima-media thickness (IMT) was measured by B-mode ultrasound imaging in all patients. Sixteen different mutations (5 never described) were found in 82 patients (49 families; mean age, 39 years; 53% women). One of the newly described mutations, the 2312-3 C-->A, was found in 24 patients (13 families). The mean of maximum thicknesses was significantly higher in the 2312-3 C-->A group than in patients with other LDLr mutations (P=.004 after adjustment for major cardiovascular risk factors). Similar results (P=.001) were obtained in the adjusted comparisons of probands only, and of the patients with similar baseline cholesterol (P=.002). This study indicates that the identification of an LDLr mutation can help to assess the risk profile of FH patients independently of the major cardiovascular risk factors.

Regression of carotid and femoral artery intima-media thickness in familial hypercholesterolemia: treatment with simvastatin

OBJECTIVE

To investigate whether high-dose simvastatin therapy could reduce carotid and femoral artery intima-media thickness (IMT) in patients with familial hypercholesterolemia (FH) to prevent cardiovascular disease.

BACKGROUND

Imaging of arterial walls with B-mode ultrasonography is increasingly used as a noninvasive surrogate marker of cardiovascular disease. Intervention trials using this modality have shown that by reducing risk factors, progression of atherosclerosis was inhibited.

METHODS

After a washout period of 6 weeks, all patients with FH started monotherapy with simvastatin, 80 mg/d, for 2 years. The primary end point was the change (in millimeters) of the mean combined far-wall IMT of predefined carotid and femoral arterial segments at 2 years.

RESULTS

We included a total of 153 patients with FH. Mean +/- SD combined baseline IMT was 1.07 +/- 0.23 mm. After treatment with simvastatin for 2 years, this IMT decreased by a mean of 0.081 mm (95% confidence interval, -0.109 to -0.053; P<.001), with its largest reduction in the femoral artery (-0.283 mm; P<.001). An actual decrease of combined IMT was seen in 69.8% of all patients.

CONCLUSIONS

High-dose simvastatin therapy reduces arterial wall IMT in more than two thirds of the patients, with its largest effect on the femoral artery. Furthermore, patients with FH who were treated with both statin and antihypertensive medication experienced a significantly greater benefit in terms of IMT reduction.

Transthoracic echocardiographic assessment of proximal ascending aorta elasticity in familial heterozygous hypercholesterolemia patients

BACKGROUND

Decreased elasticity of the aorta is associated with aging and several risk factors of atherosclerosis. The data regarding this phenomenon in patients with familial hypercholesterolemia are rather sparse.

OBJECTIVES

To evaluate non-invasively the elasticity of the proximal ascending aorta of 51 heterozygous FH patients compared to 42 normal age and gender-matched controls.

METHODS

Aortic elasticity was estimated by transthoracic echocardiography using the "pressure-strain" elastic modulus and aortic strain formulas.

RESULTS

The elastic modulus score was higher in the FH group than in the controls (1.12 +/- 0.91 10(6) dynes/cm2 vs. 0.65 +/- 0.46 10(6) dynes/cm2 respectively, P = 0.01). This was consistent in both the pediatric (0.5 +/- 0.2 10(6) dynes/cm2 vs. 0.4 +/- 0.1 10(6) dynes/cm2 respectively, P = 0.009) and adult subgroups (1.3 +/- 1.0 10(6) dynes/cm2 vs. 0.8 +/- 0.5 10(6) dynes/cm2 respectively, P = 0.0004). Aortic strain was significantly lower in patients with FH than in controls (6 +/- 4% vs. 9 +/- 5% respectively, P = 0.0002). These findings reflected decreased elasticity of the proximal ascending aorta in the FH patients. In multivariate analysis, age, serum cholesterol level and serum triglycerides level were the independent predictors of the elastic modulus score, whereas age was the predictor of aortic strain.

CONCLUSIONS

The elasticity of the proximal ascending aorta is decreased in heterozygous FH patients.

Prickly pear induces upregulation of liver LDL binding in familial heterozygous hypercholesterolemia

BACKGROUND

The hypoglycemic effect of prickly pear is well known by native local Indian population since a long time. Beside the beneficial effects on lipid metabolism, oxidation injury and platelet function has been claimed in experimental animals. We recently found an upregulation of apo-B/E receptor.

MATERIAL AND METHODS

We therefore examined 10 patients with isolated heterozygous familial hypercholesterolemia (FH) being enrolled in a dietary run-in phase of 6 weeks after dietary counselling and a further 6 weeks of prickly pear addition. Uptake of autologous (123)I-radiolabeled LDL was determined at entry as well as after 6 weeks of daily prickly pear ingestion.

RESULTS

We found a significant (p < 0.0001) increase in LDL-uptake by the liver (24.5 +/- 4.9 vs. 31.1 +/- 5.2%) and an enhanced decay in circulating blood. Total (298.0 --> 268.0 mg/dl; p < 0.0001) and LDL-cholesterol (210.5 --> 176.4 mg/dl; p = 0.0001) were significantly affected, while HDL (p = 0.0629) and triglycerides were not.

CONCLUSIONS

These findings demonstrate a significant upregulation of (123)I-LDL binding by prickly pear in FH-patients invivo and indicate that prickly pear exerts a significant hypolipidemic action via receptor upregulation.

Intima-media thickness and atherosclerotic plaques in familial defective apolipoprotein B-100 and familial hypercholesterolemia

Familial defective apolipoprotein B-100 (FDB) is a genetic disorder characterized by a decreased binding of low-density lipoprotein (LDL) particles to the LDL receptor due to defective apo B-100. Impaired LDL clearance could also be due to defects of the LDL receptor (familial hypercholesterolemia, FH). FDB was suggested to be clinically indistinguishable from classical FH. The measurement of the intima-media thickness (IMT) is an accepted method for the direct evaluation of early atherosclerosis. Thus, the aim of this study was to examine the IMT in patients with FDB in comparison to FH. Our data indicate that IMT in FDB does not differ from IMT in FH.

Positive family history for coronary heart disease and 'midband lipoproteins' are potential risk factors of carotid atherosclerosis in familial hypercholesterolemia

Patients with heterozygous familial hypercholesterolemia (FH) were examined with B-mode ultrasound in order to determine intima-media thickness (IMT) in the common carotid artery, and to uncover potential risk factors responsible for the development of IMT. Ninety seven FH subjects and 132 non FH type IIa hyperlipidemic subjects were involved in the present study. Age was found to correlate positively with IMT in both FH and non FH groups. FH individuals showed a higher IMT, along with elevated low density lipoprotein (LDL) cholesterol levels, compared with age-matched non FH individuals. To clarify potential factors contributing to the formation and development of carotid atherosclerosis, we divided the FH subjects into two subgroups, namely FH with high IMT group (HIG), and those with low IMT group (LIG). We investigated those two subgroups on the presence of angiographically documented coronary heart disease (CHD), of family history of CHD and of 'midband lipoproteins' by polyacrylamide gel electrophoresis (PAGE) analysis, by matching for age and LDL-cholesterol (LDL-C) level. Fifty percent of FH men in HIG was found to have CHD, whereas only 14% of those in LIG had CHD (P<0.05). Thirty-three percent of FH women in HIG was found to have CHD, whereas only 12% of those in LIG had CHD (P<0.05). Fifty percent of FH men in HIG was found to have 'midband lipoproteins', whereas only 7% of those in LIG had 'midband lipoproteins' (P<0.01). Seventy-three percent of FH women in HIG had 'midband lipoproteins', whereas only 21% of those in LIG had 'midband lipoproteins' (P<0.0005). Fifty-five percent of FH men in HIG was had positive family history for CHD, whereas only 14% of those in LIG had positive family history for CHD (P<0.05). Sixty-three percent of FH women in HIG was found to have positive family history for CHD, whereas only 29% of those in LIG had positive family history for CHD (P<0.05). Based on these findings, we propose that, besides age and elevated levels of LDL-C, positive family history for CHD and 'midband lipoproteins' are important determinants for the development of carotid atherosclerosis in FH individuals in Japanese population.

The use of Achilles tendon ultrasonography for the diagnosis of familial hypercholesterolemia

Differentiating FH from other causes of hypercholesterolemia has important clinical and therapeutic implications but is often not possible by standard clinical criteria. As accumulation of cholesterol in tendon is generally considered as pathognomonic of FH, we evaluated the sensitivity and specificity of clinical and ultrasonographic tendon characteristics using the data of 127 genetically ascertained FH and 160 controls with various lipid profiles. Upon clinical examination, none of the controls and 29% of FH individuals (17% FH women and 38% FH men) presented with xanthomata in Achilles tendons, but no female and only 6% of male FH patients also showed xanthomata in the extensor tendon of the hand. Amongst all possible quantitative parameters (thickness, breadth, section and roundness) of Achilles tendon (AT) measured by ultrasonography, the thickness presented the best receiver operating curves. AT thickness above 5.8 mm was the most useful threshold for diagnosis of FH, procuring sensitivity of 75% and specificity of 85%. Analysis of variation of AT thickness with age and sex indicated that this clinical criterion performed better in females older than 45 and in males under 45. In patients carrying the APOB-R3500Q mutation, AT-thickness appeared significantly less important compared with those carrying LDLR mutations. In conclusion, this study recommends identification of possible FH individuals amongst hypercholesterolemic patients using a criteria of AT-thickness over 5.8 mm eventually associated with a specific genetic test for APOB-R3500Q mutation.

Sustained long-term improvement of arterial endothelial function in heterozygous familial hypercholesterolemia patients treated with simvastatin

Patients with heterozygous familial hypercholesterolemia (hFH) are at very high risk for premature coronary heart disease. In the last decade, treatment with statins has reduced cardiovascular mortality in these patients. The aim of this study was to analyze arterial endothelial function assessed as flow-mediated dilatation (FMD) and soluble E-selectin (sE-selectin) levels in patients with hFH under a long-term lipid-lowering treatment. Twenty-five patients who completed the study received a dose of simvastatin to achieve a treatment goal of at least 30% reduction in serum low-density lipoprotein (LDL)-cholesterol (LDL-C) for 52 weeks. Functional and biochemical measurements were taken at entry, and at week 12 and 52 of treatment. FMD was measured by vascular ultrasound of the brachial artery. sE-selectin, tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 were determined by enzyme linked immunosorbent assay (ELISA). LDL-C levels were significantly reduced by treatment at week 12 and maintained at week 52 (reduction vs. baseline, 44+/-12 and 43+/-11%, respectively, P<0.0001). A significant improvement in endothelial function, measured as FMD (baseline, 4.7+/-6.2%; 12 weeks, 12.3+/-5.9%; 52 weeks, 9.7+/-4.7%; P<0.005) and a reduction in sE-selectin levels (baseline, 16.2+/-3.4 ng/ml; 12 weeks, 11.0+/-3.2 ng/ml; 52 weeks, 12.3+/-4.2 ng/ml; P<0.01) were observed. Endothelial-independent relaxation induced by nitroglycerin was not modified during the study. Our results indicate that a long-term treatment with simvastatin produced a sustained beneficial effect in endothelial function in hFH patients.

Quantification of coronary artery calcification in patients with FH using EBCT

BACKGROUND

Calcification of the coronary vessel wall is regarded as a marker of advanced coronary atherosclerosis.

METHODS

To test whether patients with heterozygous familial hypercholesterolemia (FH) exhibit excessive calcification of the coronary vessel wall, we quantified coronary artery calcium in LDL-apheresis treated FH-patients with known severe coronary artery disease (CAD) (n = 10), in patients with moderate hypercholesterolemia and known severe CAD (n = 10), and in asymptomatic controls (n = 10) using electronic beam CT. The total coronary calcium score (Agatston-Score), the number of calcified lesions and the calcified plaque volume were evaluated for this study.

RESULTS

CAD-patients with FH, although on average 10 years younger, had a significantly higher total coronary calcium score (702/2018/2890), number of lesions (34/43/49) and calcified plaque volume (700/1818/2313) compared to patients with CAD only (480/641/1362, 10/16.5/22, 480/588/1209, respectively) and controls (10/47/137, 2/4/10, 15/50/144, respectively). Furthermore, we observed a significant correlation (r = 0.93; P < 0.01) between LDL-cholesterol levels (pretreatment levels of the CAD-FH group) and the total coronary calcium score in all three groups. Our results demonstrate that coronary artery calcification is more extensive in CAD-patients with FH than in CAD-patients with moderate hypercholesterolemia. In addition, we provide evidence that the amount of calcium in the coronary vessel wall in FH patients result from a long lasting history of elevated LDL-Cholesterol levels.

CONCLUSION

These findings emphasize the significance of LDL-cholesterol as a risk factor for atherosclerosis and underline the importance of early diagnosis of CAD and early cholesterol lowering therapy in FH patients.

Arterial mechanical changes in children with familial hypercholesterolemia

Atherosclerosis is preceded by a phase of changes in the arterial wall that could have functional consequences even before the appearance of atheromatous changes. We hypothesized that early alterations of the mechanical properties of the arterial wall could precede clinical and echographic modifications. We used an automatic, computerized, ultrasonic procedure to evaluate geometric and mechanical characteristics of the common carotid artery (CCA) in normotensive children with primary familial class IIA hypercholesterolemia (FH; n=30; mean+/-SD age, 11+/-2 years old; mean+/-SD systolic/diastolic blood pressure, 109+/-9/55+/-7 mm Hg). These subjects were compared with age-matched, nonobese control subjects (n=27; 11+/-3 years old; 112+/-10/55+/-7 mm Hg). Noninvasive ultrasonic measurements were performed by the same investigator to measure the CCA luminal systolic and diastolic diameters and intima-media thickness (IMT). The cross-sectional compliance, cross-sectional distensibility, and the incremental elastic modulus of the CCA wall were then calculated. Finally, we assessed the degree of reactive hyperemia in the brachial artery produced after distal cuff occlusion and release. The changes in brachial arterial diameter in response to reactive hyperemia (endothelium-dependent dilation) and to glyceryltrinitrate (endothelium-independent dilation) were then measured. In patients with FH, we observed a significant reduction of systodiastolic variations in diameter (by 20%, P:<0.001) without a significant difference in IMT. Cross-sectional compliance and cross-sectional distensibility were significantly reduced in FH subjects (by 15%, P:<0.05 and 19%, P:<0.01, respectively). In parallel, the incremental elastic modulus was significantly increased (by 27%, P:<0.01) in children with FH. No correlation was evident between the carotid incremental modulus and either IMT or plasma low density lipoprotein cholesterol level. There was no difference in diameter of the brachial artery at rest in control and FH subjects (3.0+/-0.5 versus 3.0+/-0.4 mm). The reactive hyperemia and glyceryltrinitrate dilation were also similar in the 2 groups. However, the flow-mediated dilation of the brachial artery was smaller in the FH subjects (4.2+/-2.9%) than in controls (9.0+/-3.1%, P:<0.001). In FH, endothelium-dependent dilation was negatively correlated with the plasma low density lipoprotein cholesterol level (P:<0.04). These results indicate that increased stiffness of the CCA wall in children with FH is independent of blood pressure and could be related to endothelial dysfunction. Thus, alterations in CCA wall mechanics could be early and easily measurable markers of atheromatous changes in the arterial wall.

Long-term effects of LDL apheresis on carotid arterial atherosclerosis in familial hypercholesterolaemic patients

OBJECTIVES

To assess the long-term effect of LDL apheresis on carotid arterial atherosclerosis in severe familial hypercholesterolaemic (FH) patients.

DESIGN

Changes in existing plaque, new plaque formation and annual progression rate of carotid early plaque were evaluated by B-mode ultrasonography.

SUBJECTS

LDL apheresis group: two homozygous FH and nine heterozygous FH patients received a combination of LDL apheresis and cholesterol-lowering drug therapy for a mean of 7.8 years.

CONTROL GROUP

10 heterozygous FH patients were maintained by medication only for a mean of 5.5 years.

RESULTS

As a result of LDL apheresis treatment, LDL cholesterol levels reduced from 16.0+/-3.60 to 6.43+/-0.07 mmol L(-1) in homozygous FH patients and from 11.5+/-2.46 to 4.32+/-1.2 mmol L(-1) in heterozygous FH patients. During the long-term treatment period, the existing plaque tended to progress and new plaque formation in carotid arteries was also observed in both groups. The annual progression rate of mean maximum intima-media thickness in the common carotid artery was a mean of -0.0023+/-0.0246 mm year(-1) in heterozygous FH patients in the LDL apheresis group, suggesting regression. This was significantly lower when compared with the control group, which had a mean of 0.0251+/-0.0265 mm year(-1) CONCLUSION: The results suggest that the long-term treatment with combined LDL apheresis and drugs may delay the progression of the atherosclerotic process and prompt the stabilization of atheromatous plaque in severe FH patients.

Frequency analysis of echo texture in tendon

A texture discriminant based on spatial frequencies is proposed for characterizing B-scans of Achilles' tendon. The anisotropic echo texture of normal tendon has an ellipsoidal spatial spectrum that can be quantified by the ratio of the major-to-minor axis and by the direction of the major axis. Applying a moving window to the B-scan, a corresponding tissue elliptical axis ratio (TEAR) image is derived that segments out tendon. The algorithm was applied to B-scan images taken from 13 volunteers, 6 of whom had tendon abnormalities: tendon rupture (n = 3) or cholesterol deposits (xanthomas) in patients with heterozygous familial hypercholesterolemia (n = 3). The average TEAR value was 1.75 +/- 0.17 for normal tendon, 1.04 +/- 0.06 for torn tendon, and 1.31 +/- 0.16 for tendons with xanthomas. The dispersion of the directionality vectors was used to further differentiate tendons with xanthomas from normal tendons. This technique appears to be useful for characterizing both diffuse and focal tendon abnormalities.

Characteristic cardiovascular manifestation in homozygous and heterozygous familial hypercholesterolemia

BACKGROUND

The aortic valve dysfunction of patients with homozygous familial hypercholesterolemia (FH) suggests that hypercholesterolemia affects not only coronary arteries but also the aortic valve. We studied the aortic root of patients with homozygous FH and those of patients with heterozygous FH to characterize the premature atherosclerotic lesions by using histopathologic specimens.

METHODS AND RESULTS

The aortic roots of 10 patients with homozygous FH, age 9 to 58 years, were studied by cardiac catheterization with several angiographies. The aortic roots of 39 patients with heterozygous FH under age 60 years were also examined for aortic and mitral valvular functions by color Doppler echocardiography, and 30 normocholesterolemic patients with coronary artery disease were examined as control subjects. In addition, in 22 patients with FH and 20 control subjects, the internal diameter of the aortic annulus and the aortic ridge in cardiac cycles were measured. Of the 10 homozygotes with FH, 8 patients had aortic regurgitation demonstrated by aortography; 3 of them showed significant transvalvular pressure gradients. Stenotic changes of coronary ostia were observed in 8 of the 10 homozygotes with moderate coronary atherosclerosis. Of the 39 heterozygotes with FH, 10 patients had aortic regurgitation shown by Doppler echocardiography, as did only 1 of the 30 control subjects (P <.05). The average diameter and distensibility of the ascending aorta were significantly reduced in the heterozygotes compared with the control subjects. The surgically resected cusp specimens of aortic valves obtained from 1 homozygous and 1 heterozygous patient showed significant thickening of the cusp with foam cell infiltration.

CONCLUSIONS

Premature atherosclerosis in FH had a characteristic distribution, affecting the aortic root dominantly. The involvement of the aortic valve indicating "hypercholesterolemic valvulopathy" was a peculiar feature of FH, especially its homozygous form, but was reminiscent of ubiquitous processes caused by hypercholesterolemia.

Assessment by transesophageal echography of atherosclerosis of the descending thoracic aorta in patients with hypercholesterolemia

This study assesses atheromatous lesions and aortic stiffness of the descending thoracic aorta (DTA) in patients with hyperlipidemia by transesophageal echography (TEE) and investigates the relations between atherosclerotic lesions and aging or serum cholesterol levels in these patients. Subjects included 16 patients with familial hypercholesterolemia (FH), 15 non-FH hyperlipidemic patients (non-FH), and 17 age-matched normal subjects. With use of TEE, the DTA was divided into 4 longitudinal portions of equal length, and the atheromatous lesions of each portion of DTA were scored according to their character and extension by biplane 2-dimensional TEE. The scores of atheromatous lesions from all 4 portions were added together to give the total atheromatous score. Then, after measuring the instantaneous dimensional changes of DTA in a cardiac cycle by M-mode TEE and blood pressure (BP) by a cuff method, we calculated the aortic stiffness parameter beta = ln(systolic BP/diastolic BP)/([Dmaximum - Dminimum]/Dminimum). The beta was significantly higher in FH and non-FH subjects than in normal subjects. In both FH and non-FH subjects, the total atheromatous score correlated with total serum cholesterol levels (r = 0.64 [p <0.01]; r = 0.58 [p <0.05], respectively). There were significant correlations between age and beta in all 3 groups (FH, r = 0.67 [p <0.005]; non-FH, r = 0.53 [p <0.05]; normal subjects, r = 0.49 [p <0.05]), and the slopes of the regression lines of FH and non-FH subjects were much steeper than those of normal subjects. The incidence of atherosis in the DTA was significantly higher in hyperlipidemic patients than in normal subjects, even among the younger members of the hyperlipidemic population with progressive aortic stiffness.

Large-artery elastic properties in young men : relationships to serum lipoproteins and oxidized low-density lipoproteins

Measures of arterial elasticity have been proposed as surrogate markers for asymptomatic atherosclerosis. We investigated the relations of serum lipoproteins, oxidized low-density lipoprotein (ox-LDL), and familial hypercholesterolemia (FH) to arterial elasticity among young men. As a marker of arterial elasticity we measured compliance in the thoracic aorta by using magnetic resonance imaging and in the common carotid artery by using ultrasound. LDL diene conjugation was used as a marker of ox-LDL. In study I, 25 healthy men (aged 29 to 39) were classified into 2 extreme groups according to previously measured high-density lipoprotein cholesterol to total cholesterol ratio (HDL-C/TC ratio). In study II, the healthy men were used as controls for 10 age matched asymptomatic patients with FH. In healthy men, the group with low HDL-C/TC ratio had decreased carotid artery compliance (2. 3+/-0.4% versus 1.9+/-0.5%/10 mm Hg, P=0.034). In univariate analysis, the compliance of the carotid artery associated with ox-LDL (r =-0.49, P=0.016) and HDL-C/TC ratio (r=0.41, P=0.040). In multivariate regression analyses, ox-LDL was the only independent determinant for compliance of the carotid artery (P=0.016). Aortic elasticity was not related to standard lipid variables, but the compliance of the ascending aorta associated with ox-LDL (r=-0.44, P=0.030). In FH patients, arterial elasticity was similar to that in controls. We conclude that elasticity of the common carotid artery is affected by serum lipid profile in young men. The current study demonstrates for the first time an in vivo association between ox-LDL and arterial elasticity suggesting that oxidative modification of LDL may play a role in the alteration of arterial wall elastic properties.

Usefulness of electron beam tomography in adolescents and young adults with heterozygous familial hypercholesterolemia

BACKGROUND

Because of the success of secondary prevention of coronary events by intense risk factor modification, a more precise measure of atherosclerosis in youth would have great clinical value both in the design of clinical trials for the demonstration of the usefulness of coronary disease prevention early in life and in guiding therapy. Identification of calcium in coronary arteries by electron beam tomography has been associated with severity of atherosclerosis in adults.

METHODS AND RESULTS

Twenty-nine youths 11 to 23 years old with familial hypercholesterolemia (average LDL cholesterol, 5.95 mmol/L) underwent electron beam tomography as well as comprehensive risk factor assessment with measurement of total cholesterol, triglycerides, HDL cholesterol, lipoprotein (a), apolipoprotein E phenotype, blood pressure, body mass index, and history of tobacco use. Significant coronary calcium was identified in 7 of 29 subjects. Increased body mass index was significantly associated with the presence of coronary calcium (25.3 versus 20.6 kg/m2, P<0.03). No other risk factors were associated with the presence of coronary calcium.

CONCLUSIONS

Coronary calcium, uncommonly identified before the fourth decade, was found in a significant percentage of adolescents and young adults with familial hypercholesterolemia. Overweight may increase the likelihood of coronary calcium being present in individuals already at high risk.

Sonography of Achilles tendon xanthomas in patients with heterozygous familial hypercholesterolemia

OBJECTIVE

Xanthomas are an essential diagnostic criteria of familial hypercholesterolemia. The objective of this study was to determine if xanthomas of the Achilles tendon can be revealed on sonography when the condition is clinically unsuspected in patients with heterozygous familial hypercholesterolemia.

SUBJECTS AND METHODS

Ninety-four patients (52 females, 42 males; 12-73 years old; mean age, 44 years) with a proven diagnosis of heterozygous familial hypercholesterolemia were studied. Achilles tendons of these patients were clinically evaluated and examined with sonography. Size and echo structure of the Achilles tendons were categorized as normal, having hypoechoic nodules (grade 1), or diffusely hypoechoic with a heterogeneous echo structure (grade 2).

RESULTS

Sixty-two patients had positive physical examination findings for Achilles tendon xanthomas. Fifty-seven (92%) of these patients had abnormally large tendons (> or =7.1 mm) on sonography. Grade 1 or grade 2 echo structure compatible with xanthomatosis was found in at least one Achilles tendon of all 62 patients. Of the 94 patients in the study group, 32 patients had negative or indeterminate physical examination findings for Achilles tendon xanthomas. Sonography showed that two (6%) of these patients had an enlarged (> or =7.1 mm) Achilles tendon. Grade 1 or grade 2 echo structure compatible with xanthomatosis was found in 26 (81%) of these 32 patients.

CONCLUSION

Sonography is significantly more sensitive than physical examination for the detection of Achilles tendon xanthomas in patients with heterozygous familial hypercholesterolemia and normal-sized Achilles tendons. Our study suggests that sonography may play an important role in the early diagnosis of heterozygous familial hypercholesterolemia.

Antibody titers against oxidized LDL are not elevated in patients with familial hypercholesterolemia

Antibodies against oxidized low density lipoproteins (Ox-LDLs) have been proposed to be independent predictors of atherosclerosis development. The main aims of the current study were to (1) compare antibody titers to Ox-LDL in patients with heterozygous familial hypercholesterolemia (n=51) with those in matched controls (n=45) and (2) analyze whether the antibody titers were related to the extent of atherosclerosis, as assessed cross-sectionally and prospectively by ultrasonography in the 2 study groups. Antibody titers were determined with a solid-phase ELISA, and plates were coated with the antigens Ox-LDL or malondialdehyde-treated LDL (MDA-LDL) as well as with the postcoat only (5% dry milk powder). Antibody titers were expressed as absorbance [(value in patient serum minus that in postcoat) divided by (Internal Standard Serum minus postcoat)]. There were no significant differences in antibody titers against Ox-LDL or MDA-LDL between the group of patients with familial hypercholesterolemia and the controls. In cross-sectional comparisons, no significant associations were observed between the intima-media thickness of the carotid or femoral arteries and antibody titers against Ox-LDL or between plaque occurrence and these titers. Patients with a history of myocardial infarction had significantly lower IgM titers against Ox-LDL compared with patients without a history of myocardial infarction and with controls. In conclusion, mean values for antibody titers against Ox-LDL were not increased in the patient group compared with a healthy control group, and no positive, significant relationship was observed between antibody titers and the extent of atherosclerosis, as measured by ultrasound, in the carotid or femoral arteries. Taken together, these findings indicate that the relationship between the autoimmune response to Ox-LDL and the extent of atherosclerosis is more complex than previously anticipated.

[Noninvasive investigation of endothelial function in patients with hypertension and hypercholesterolemia (HCE)]

AIM

Functional assessment of endothelium by endothelium-dependent and non-endothelium dependent response of the brachial artery (BA) in patients with risk factors for atherosclerosis.

MATERIALS AND METHODS

The ACUSON 128 XP/10 unit furnished with linear meter with phase grid (7.0 MHz) was employed in two-direction scanning mode to measure BA diameter at rest, under reactive hyperemia (endothelium-dependent response) and after sublingual intake of 0.01 mg of nitroglycerin (non-endothelium-dependent response) in 12 patients with blood hypertension (group 3), 10 subjects with family hypercholesterolemia (group 2) and 10 healthy subjects (group 1, control).

RESULTS

The flow-dependent dilatation remained unchanged in BH patients (9.4%) and lowered in HCE patients (3.0%) compared to controls (9.5%). Nitroglycerin-induced dilatation was not significantly different in patients with family hypercholesterolemia (16.6%), hypertensive subjects (14.5%) and healthy controls (20.5%).

CONCLUSION

The ultrasound method of detection of endothelial dysfunction is demonstrated. Endothelial dysfunction in patients with familial hypercholesterolemia may contribute to development of atherosclerosis.

[Familial hypercholesterolemia: involvement of cerebral major arteries (communication 1)]

Ultrasound dopplerography, MR tomography were performed to assess the brain, major cerebral arteries and audiometry was conducted to study cochleovestibular system in 38 patients aged 16-63 years with heterozygous family hypercholesterolemia. Vascular disorders and defects in the white brain matter (in patients with transitory hypertension) were registered. Complications of cerebral atherosclerosis (brain infarction, perception cochleovestibular alterations) contributed to aggravation of ischemic heart disease. Patients with heterozygous family hypercholesterolemia should be observed and treated by cardiologist, neuropathologist and psychoneurologist to prevent cardiocerebral complications.

Non-invasive ultrasound detection of endothelial dysfunction

With high resolution ultrasound we assessed endothelial function in subjects at risk of atherosclerosis. We used ACUSON 128XP/10 system with 7.0 MHz linear array transducer. Three groups of patients (pts) were studied: 12 patients with essential hypertension, ten patients with 2A familial hyperholesterolamia and ten controls without vascular risk factors. We measured the diameter of brachial artery at rest, during reactive hyperaemia (with increased flow causing endothelium-dependent dilation), and after sublingual 0.01 mg nitroglycerin (causing endothelium-independent dilation). Flow-mediated dilation is not impaired in essential hypertension (9. 4%) compared with controls (9.5%) and impaired in patients with familial hyperholesterolaemia (3.0%). NTG-induced dilation is not impaired in familial hyperholesterolaemia (16.6%) and essential hypertension (14.5%) compared with controls (20.5%). The effect of hypolipidaemic influence (probucol and plasmapheresis) was assessed in a separate study. These results demonstrate the capability of ultrasound in detection of endothelial dysfunction, and suggest that endothelial dysfunction in patients with familial hyperholesterolaemia is one of the risk factors for atherosclerosis. The parameters of endothelial function may be used as markers of hypolipidemic influence on patients with hyperholesterolaemia.

Cholesterol and carotid artery wall in children and adolescents with familial hypercholesterolaemia: a controlled study by ultrasound

The carotid artery wall was studied with ultrasound in 23 children and adolescents with familial hypercholesterolaemia and in 23 age-matched healthy controls. The study revealed changes in the carotid artery wall related both to familial hypercholesterolaemia and to age. In the control subjects, the carotid artery wall became stiffer with age. In the patients with hypercholesterolaemia, no clear age-dependence was found, but wall stiffness correlated with total and low-density lipoprotein cholesterol. The intimal-medial wall thickness was associated with serum total cholesterol, low-density lipoprotein and triglyceride concentrations, and correlated inversely with the ratio of high-density lipoprotein to total cholesterol. Carotid artery wall properties seem to be associated with the degree of hypercholesterolaemia and the high-density lipoprotein-to-total cholesterol ratio even in children. In childhood and adolescence it is already possible, with ultrasound, to detect changes in the arterial wall related both to familial hypercholesterolaemia and to age.

Long-term follow-up by coronary angiography in a patient with heterozygous familial hypercholesterolemia: a case report

A 47-year-old man with heterozygous familial hypercholesterolemia was followed up by coronary angiography for 9 years. During these 9 years, he experienced inferior myocardial infarction twice, at segment 1 of the right coronary artery. A coronary atherosclerotic lesion (50% stenosis) was also present at segment 6 of the left anterior descending coronary artery. This lesion remained unchanged for the first 7 years, but then rapidly progressed to 90% stenosis in the 8th year. While the rate of the progression of coronary atherosclerosis is generally unpredictable, it may progress rapidly in this case of heterozygous familial hypercholesterolemia.

[Favorable effect of treatment with statins on the intima of the common carotid artery in patients with familial hyperlipoproteinemia]

BACKGROUND

In recent years evidence was provided that by measuring the width of the intima of the carotid artery, evaluated by sonography, it is possible to assess the development of arteriosclerosis. The authors used this method to evaluate hypolipidaemic treatment.

METHODS AND RESULTS

The authors followed-up by clinical and laboratory methods and treated for a period of 47 months 63 patients with familial hyperlipoproteinaemia. At the beginning and at the end of the follow-up period they made sonographic examinations of the common carotid artery. In 31 patients treated by statins they observed statistically significant changes: cholesterol declined by 23%, LDL cholesterol by 25.3%. The maximal rate in the common carotid artery (ACC) declined from 93 +/- 22 to 73 +/- 13 cm/s. The diameters of the ACC increased from 6.0 +/- 0.8 to 6.5 +/- 0.8 mm. The intima of the ACC diminished from 0.84 +/- 0.26 to 0.75 +/- 0.20 mm. In 22 patients treated with fibrates the anticipated lipid changes occurred. The diameter of ACC did not change, the decline in the width of the intima of the ACC was not statistically significant. In 10 patients who decided that they wanted only dietary treatment the changes in the investigated parameters were small.

CONCLUSIONS

In patients with familial hyperlipidaemia who were treated with statins for almost four years the authors observed a diminution of the width of the intima of the common carotid artery which is considered a sign of regressing atherosclerosis.

Carotid intima-media thickness in young patients with familial hypercholesterolaemia

OBJECTIVE

To assess the extent of early atherosclerotic changes of the carotid arteries in young patients with familial hypercholesterolaemia (FH) detected as increased intima-media thickness (IMT), and to determine the relations between IMT and some clinical and blood variables such as lipid and lipoprotein(a) (Lp(a)) concentration and haemostatic factors.

DESIGN

The IMT of the carotid bifurcation, the proximal 1 cm of the internal carotid artery, and the distal 1 cm of the common carotid artery was determined in all subjects using B mode ultrasonography. Blood lipids, fasting glucose, and several haemostatic variables were also analysed.

SUBJECTS

28 patients with FH (12 males and 16 females aged 11 to 27 years, one homozygote, 27 heterozygotes) and 28 sex and age matched normolipidaemic healthy subjects.

RESULTS

The mean carotid IMT (the average of six measurements of the maximum far wall IMT in the three carotid segments on each side) was significantly greater in patients with FH than in controls (mean (SD) 0.71 (0.15) v 0.49 (0.08) mm, P < 0.001). In all subjects, the mean IMT was significantly correlated with total cholesterol (r = 0.59), low density lipoprotein (LDL) cholesterol (r = 0.60), triglycerides (r = 0.27), and systolic blood pressure (r = 0.47). No correlation was found between the mean IMT and Lp(a), fibrinogen, tissue plasminogen activator, and plasminogen activator inhibitor 1.

CONCLUSIONS

The majority of young patients with FH have a greater intima-media thickness of the carotid arteries than healthy subjects. Since the individual susceptibility of patients with FH to increased LDL cholesterol is different, B mode ultrasonography could provide a useful tool to identify those who are more likely to develop premature atherosclerotic disease.