Atherosclerosis of the carotid arteries in young patients with familial hypercholesterolemia

Non-coronary atherosclerotic cardiovascular disease in patients with familial hypercholesterolaemia

Objective: Familial hypercholesterolaemia (FH) is a common autosomal dominant inherited disease, affecting 1 in 200-500 individuals worldwide. FH is characterized by elevated circulating low-density lipoprotein cholesterol (LDL-C) concentrations. Its association with increased risk of coronary heart disease (CHD) (>10-fold, compared with patients without FH) is well documented. However, the association between FH and non-CHD atherosclerotic cardiovascular disease (ASCVD) risk has been poorly documented.Methods: PubMed was searched for English language publications regarding the association between FH and carotid artery stenosis, stroke, peripheral artery disease (PAD; lower limbs and other arterial beds), aortic valve calcification (AoVC), aortic and renal artery disease, chronic kidney disease, atrial fibrillation and heart failure, from conception until 22 December 2019.Results: Despite the small number of available studies, as well as their characteristics (sample size, diagnostic criteria used, retrospective or cross-sectional design), there is evidence for a positive association between FH and stroke, PAD or AoVC. More data are needed for definitive conclusions regarding aortic and renal artery disease, chronic kidney disease, atrial fibrillation and heart failure. There is paucity of data with respect to homozygous FH. Increased lipoprotein (a) concentrations, often seen in FH patients, may also contribute to this non-CHD atherosclerotic process. A key question is whether statins or other LDL-C-lowering therapies, provide an additional reduction in the risk of these less-recognized vascular and non-vascular complications in FH patients.Conclusions: Heterozygous FH is associated with increased risk for stroke, PAD and AoVC. Clinicians should take these non-CHD ASCVD aspects into consideration for optimal management of FH patients.

Carotid artery plaques and intima medial thickness in familial hypercholesteraemic patients on long-term statin therapy: A case control study

BACKGROUND AND AIMS

Statins reduce subclinical atherosclerosis and premature atherosclerotic cardiovascular disease (ASCVD) in patients with familial hypercholesterolemia (FH). However, some FH patients still develop ASCVD despite statin therapy. We compared subclinical atherosclerosis assessed by carotid plaque presence and intima media thickness (C-IMT), in long-term statin-treated FH patients and healthy controls. Furthermore, we analysed whether carotid ultrasonography findings associated with subclinical coronary atherosclerosis.

METHODS

We assessed the presence of carotid plaques and C-IMT in 221 asymptomatic heterozygous FH patients (48% men; 46 ± 15 years) on long-term (10.0 ± 7.8 years) statin treatment and 103 controls (32% men, 47 ± 16 years).

RESULTS

The frequency of carotid plaques and C-IMT did not differ significantly between the FH patients and controls (69 (31%) versus 24 (23%), p = 0.1 and 0.58 ± 0.13 versus 0.58 ± 0.12 mm, p = 0.9, respectively). In a subgroup of 49 FH patients who underwent cardiac computed tomography, coronary artery calcification correlated with carotid plaque presence (R = 0.47; p = 0.001), but not with C-IMT (R = 0.20; p = 0.2).

CONCLUSIONS

Carotid plaques and C-IMT did not differ between long-term statin-treated heterozygous FH patients and healthy controls. This shows that long-term statin treatment in these FH patients reduces carotid atherosclerosis to a degree of a healthy population. These findings strongly suggests that sonography of the carotid arteries during follow-up of statin-treated FH patients has limited value.

Mechanisms and therapy of atherosclerosis and its clinical complications

In 1913, exactly 100 years ago, Nikolai Nikolaevich Anichkov (1885-1964) and Semen Sergeevich Chalatov (1884-1951) discovered in St. Petersburg, Russia, that atherosclerosis of large arteries is critically dependent on cholesterol. The inflammatory nature of atherosclerosis was first observed and suggested by Rudolf Virchow in 1856. Today, we have orally active drugs at our disposition that not only lower cholesterol levels but also interfere with vascular inflammation and atherogenesis. The disease process is multifactorial and its development is accelerated by modifiable and given risk factors such as cigarette smoking, dyslipidemia, arterial hypertension, diabetes, obesity, physical inactivity, estrogen deficiency, chronic renal disease, genetic predisposition, and the physiological aging process, among others. The present issue of Current Opinion in Pharmacology features a collection of articles by clinicians and scientists-many of whom are world authorities in their field-on mechanisms, preventive measures, clinical complications, and treatment of coronary artery disease. This monograph provides a '2013 update' on the pathogenesis, prevention, and therapy of atherosclerosis.

Coronary computed tomographic angiographic findings in asymptomatic patients with heterozygous familial hypercholesterolemia and null allele low-density lipoprotein receptor mutations

Heterozygous familial hypercholesterolemia (HeFH) can be associated with early coronary artery disease (CAD) in asymptomatic patients. The objectives of the present study were to assess the prevalence and magnitude of subclinical CAD in patients with HeFH using coronary computed tomographic angiography (CCTA) and to determine the clinical and genetic profile of those at the greatest risk of CAD. The study included 50 consecutive patients with HeFH diagnosed according to the Dutch Lipid Clinic Network criteria and a control group of 70 healthy subjects. The findings from CCTA for the patients with HeFH were compared with those from the control group, who had been referred for CCTA as a part of a preventive medical examination. In 82% of the patients with HeFH, genetic DNA was screened for low-density lipoprotein receptor (LDLR) gene mutations using a microarray. CCTA revealed a significantly greater Agatston calcium score in the study group than in the control group (260 vs 46; p = 0.002). The prevalence of CAD in the patients with HeFH was 48%. It was significant in 26%, involving mainly the proximal segments of the coronary arteries. In the control group, the prevalence of CAD was 33% and was significant in 5% (p <0.05 for prevalence and severity of CAD compared to patients with HeFH). In those with HeFH, increased age, null allele LDLR mutations, and low high-density lipoprotein blood levels at diagnosis showed a statistically significant association with CAD (p <0.05). In conclusion, patients with HeFH present with a greater prevalence, extension, and severity of subclinical CAD than the general population. Increased age, low high-density lipoprotein levels, and LDLR null allele mutations are related to the occurrence of CAD. CCTA has emerged as a useful technique for the screening of subclinical CAD in patients with HeFH.

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.

Coexisting dysbetalipoproteinemia and familial hypercholesterolemia. Clinical and laboratory observations

Type III dysbetalipoproteinemia and familial hypercholesterolemia (FH) are two metabolic disorders giving rise to severe disturbances of lipid homeostasis and premature atherosclerosis. Both metabolic abnormalities have a genetic basis and co-occurrence in the same patient has seldom been described. Because of the unique structure of the French Canadian population, there was an opportunity to observe patients with both dysbetalipoproteinemia (E2/2 homozygotes) and FH (N=14) and to compare their clinical data with that of patients with type III (N=75), patients with FH (N0.7 and the presence of beta-VLDL on electrophoresis. Presence of a low density lipoprotein receptor, LDL-R, mutation should be suspected in a type III patient with a LDL-C level above 3.0 mmol/l and a family history of premature CAD. In the group of patients studied, the coexistence of dysbetalipoproteinemia and heterozygous FH does not appear to increase the prevalence of cardiovascular complications above that observed among control type III or control E3/3-FH patients. Thus, the presence of two epsilon2 alleles in these patients affects the expression of the abnormal LDL-R allele and the resulting phenotype substantiates the non additive effects of alleles at these two loci (epistasis).

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.

Short-term efficacy and safety of pravastatin in 72 children with familial hypercholesterolemia

The safety, tolerability, and efficacy of a 12-wk treatment with pravastatin, 5, 10, and 20 mg/d, was evaluated in 72 children with heterozygous familial hypercholesterolemia (FH) in a double-blind, randomized and placebo-controlled study. The results show that pravastatin was well tolerated and that adverse events were mild and equally distributed among the three treatment groups. Plasma total and LDL cholesterol levels were significantly reduced in all pravastatin treatment groups, in comparison with the control group; -24.6% (-28.1 to 21.0) and -32.9% (-37.0 to -28.6), for mean change and 95% confidence interval, respectively. In four children plasma LDL cholesterol levels were reduced within normal limits for sex and age. HDL cholesterol increased in the pravastatin 20-mg group, +10.8% (+3.4 to +18.8), whereas plasma apo B100 and very LDL (VLDL) cholesterol levels were reduced within all pravastatin-treated groups -26.8% (-31.2 [corrected] to -21.7) and -24.5% (-35.0 to -12.3). These data show that short-term pravastatin treatment of children with FH is safe and effective, although long-term dose titration studies with 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors need to be performed, to reduce plasma LDL cholesterol levels below a predefined level. The results of these studies have to be awaited before new treatment strategies are to be considered in these children.

Transesophageal echocardiography in patients with focal cerebral ischemia of unknown cause

BACKGROUND AND PURPOSE

Identification of cardioembolic stroke is often limited by the difficulties involved in the detection of thrombi or the risk factors for thrombus formation. Patients in sinus rhythm with nondiagnostic transthoracic echocardiogram (TTE) and without carotid artery stenosis represent a subset in whom diagnostic recommendations are lacking. The aim of this study was to determine the value of transesophageal echocardiography (TEE) for diagnosis and therapy in this population.

METHODS

Thirty patients with the characteristics described above were studied prospectively with the use of blood analysis, TTE, TEE, and Holter monitoring (in patients with atrial thrombus).

RESULTS

TTE was abnormal in 16 of 30 patients, but no embolic source was identified. TEE disclosed left atrial appendage thrombus in 3 of 30 patients, atrial septal aneurysm in 2 of 30 patients, patent foramen ovale in 7 of 30 patients, and aortic plaques in 19 of 30 patients. The Tee resulted in a change of therapy in 3 of the 30 patients studied.

CONCLUSION

This study demonstrates that TEE is a helpful diagnostic tool in delineating the risk of cardioembolic stroke and demonstrates significant pathology even in a subset of patients deemed to be at low risk. This additional new information led to a substantial change in therapy in 3 of 30 patients.

Concurrent development of hemiplegia and angina pectoris in a 46-year-old man with familial hypercholesterolemia and elevated serum Lp(a) concentrations

We report a 46-year-old man with familial hypercholesterolemia who simultaneously developed angina pectoris and left hemiplegia. Angiography revealed complete tapering occlusion of the right internal carotid artery and a 75% stenosis of the right coronary artery. In addition to hypercholesterolemia, his serum Lp(a) levels were very high, with a mean (+/- SE) of 62 +/- 2 mg/dl.

Who should treat familial hypercholesterolemia?

The treatment of various manifestations of familial hypercholesterolemia can involve a variety of health professionals over the lifetime of a given patient. The first task is to diagnose the condition. This should be done by primary physicians, i.e., pediatricians, family practitioners and internists. The same professionals, with help from dietitians as necessary, should treat the hypercholesterolemia in most cases. Homozygotes and difficult to treat heterozygotes should be referred to endocrinologists or lipidologists. The various cardiovascular manifestations, at one time or another, may require consultation with cardiologists, neurologists, radiologists, and cardiac or vascular surgeons. Physiatrists and physical and occupational therapists also may contribute to patient care.

Familial hypercholesterolaemia: pilot study to identify children at risk

AIMS

To evaluate a more effective method of identifying children with familial hypercholesterolaemia by screening a population at high risk.

METHODS

Domiciliary measurement of random cholesterol concentration was made in 200 children who were first or second degree relatives of subjects with premature onset coronary artery disease. Measurements were taken by a health visitor using a portable analyser.

RESULTS

Twelve new cases of familial hypercholesterolaemia were identified during the first nine months of the study. Random cholesterol concentrations were within the normal range (< 5.2 mmol/l) in 70.5% of samples tested. Forty two (21%) of patients tested had a borderline cholesterol (5.2-5.9 mmol/l) but 50% of these fell within the normal range when fasting capillary samples were analysed. Children with significant hypercholesterolaemia on random testing (concentrations of > 5.9 mmol/l) (8.5%) also had fasting venous blood assayed for high density lipoprotein (HDL) cholesterol and tri-glyceride in the laboratory. Results indicated that 6.5% of patients screened were at high risk of cardiovascular disease (ratio of total: HDL cholesterol of > 4.5), and 1% had a moderately increased risk (ratio 3.5-4.5).

CONCLUSIONS

Children with familial hypercholesterolaemia can be identified from a selected "high risk" population by measuring random capillary cholesterol concentration.

Familial defective apolipoprotein B100: clinical characteristics of 54 cases

Familial defective apolipoprotein B100 (FDB) is a recently identified dominantly inherited genetic disorder, which is characterized by a decreased affinity of low density lipoprotein (LDL) for the LDL receptor. FDB is caused by a G to A mutation at nucleotide 10 708 in exon 26 of the apo B gene creating a substitution of glutamine for arginine in the codon for amino acid 3500. To determine the consequences of the arginine(3500)----glutamine mutation on plasma lipid levels and other clinical features, we have investigated 54 FDB heterozygotes from Germany (24 men, 30 women, mean age 37.2 (4-73) years). The average total cholesterol level in plasma was 308 mg/dl (average LDL-cholesterol 242 mg/dl), which was 116 mg/dl (120 mg/dl) above the 50th percentile of the age and sex-matched controls reported in the LRC population studies (Lipid Research Clinics' Program 1980). Tendon xanthoma and arcus lipoides were present in 25.9% and 22.2% of the patients, respectively. Plaques in the carotid arteries, determined by duplex scanning, were present in 38.9%, and coronary artery disease was present in 22.2%. This study shows that the combination of tendon xanthoma, arcus lipoides and premature atherosclerosis is no longer totally appropriate for the diagnosis of familial hypercholesterolemia (FH). It rather seems that these features are characteristic of a defective LDL receptor pathway, which could be caused by a defective LDL receptor or a defective ligand apo B100. The distinction between FH and FDB may have therapeutic implications, because certain lipid lowering drugs act by stimulation of the LDL receptor, which has a normal function in FDB.

Familial defective apolipoprotein B-100: a common cause of primary hypercholesterolemia

Familial defective apolipoprotein B-100 (FDB) is a recently identified dominantly inherited genetic disorder characterized by a decreased binding of low density lipoprotein (LDL) to the LDL receptor due to defective apo B-100. FDB is caused by a G to A mutation at nucleotide 10,708 in exon 26 of the apo B gene creating a substitution of glutamine for arginine in the codon for amino acid 3500. The arginine (3500)----glutamine mutation has been observed in several populations in North America and Europe with a similar frequency of approximately 1/500 to 1/700. Haplotype analysis has demonstrated that the arginine(3500)----glutamine mutation occurs on the same chromosomal background. The fact that all individuals with FDB are of Caucasian extraction implies that the mutation has its origin in this population. The arginine(3500)----glutamine mutation has a profound impact of varying strength on the plasma LDL cholesterol level, leading to heterogeneous clinical expression comparable to "classic" familial hypercholesterolemia (FH) caused by a defective LDL receptor: tendon xanthoma, premature atherosclerosis and arcus lipoides. The present data suggest that the combination of these clinical features is no longer appropriate for the diagnosis of LDL-receptor-defective FH, but may be a common feature of a defective LDL receptor pathway originating either from defective LDL receptors or from malfunctioning ligand apo B-100.

Relative protection from cerebral atherosclerosis of young patients with homozygous familial hypercholesterolemia

It is well known that hypercholesterolemia is correlated with coronary atherosclerosis, but no definite information is available on its association with cerebrovascular atherosclerosis. We studied 10 young patients (age 3-32 years) with homozygous familial hypercholesterolemia (FH), together with 3 normal relatives as healthy controls. Extra- and intracranial Doppler examination, MRI and cerebral blood flow by SPECT and 99mTc-HM-PAO were performed on all. Six out of 10 patients already had signs and symptoms of coronary heart disease, but all patients were free from ischemic brain lesions, as small as detectable at MRI, and had normal cerebral blood flow. Two patients presented significant stenosis of the carotid arteries at Doppler examination. Young patients with homozygous FH have early and clinically evident coronary atherosclerosis, while overt disease in the cerebral district is delayed despite the extremely elevated plasma cholesterol concentration. This was also confirmed by the autopsy of two patients, who died after the study and whose cerebral arteries were totally free from atherosclerotic lesions. The age, at which flow-reducing atherosclerotic lesions develop in hypercholesterolemic patients, differs with regard to the arterial district involved.

Changes of atherosclerosis of the carotid arteries due to severe familial hypercholesterolemia following long-term plasmapheresis, assessed by duplex scan

Three males, aged 15, 22, and 25 years, have been followed for Familial hypercholesterolemia (FH) from 1968 and 1976 onward, being treated by plasmapheresis for 2 to 5 years continuously, at 1- to 2-week intervals. Whereas two patients have been continuously treated to date, the third discontinued plasma exchange after 4 years and has been reevaluated 6 years later. Discontinuation of plasma exchange led to progression of atherosclerosis of the carotid arteries documented by duplex scan, whereas one patient exhibited marked regression of former impressive soft plaque-formation and one patient showed no significant change. Two-dimensional computer-analysis suggested a reduction of plaque mass of up to 45% in one patient.