Cardiovascular features of homozygous familial hypercholesterolemia: analysis of 16 patients

High density lipoprotein infusion therapy: A review

Increased cholesterol-rich, low-density, non-calcified atheromas as assessed by computer coronary tomography angiography (CCTA) analyses have been shown to predict myocardial infarction significantly better than coronary artery calcium score or the presence of obstructive coronary artery disease (CAD) as evaluated with standard coronary angiography. Low serum high-density lipoprotein (HDL) cholesterol values are an independent risk factor for CAD. Very small, lipid-poor preβ-1 HDL particles have been shown to be most effective in promoting cellular cholesterol efflux. HDL infusions have been documented to reduce aortic atherosclerosis in cholesterol-fed animal models. However, human studies using infusions of either the HDL mimetic containing recombinant apolipoprotein (apo) A-I Milano or Cerenis Compound-001 with native recombinant apoA-I have been mainly negative in promoting coronary atherosclerosis progression as assessed by intravascular ultrasound. In contrast, a study using 7 weekly infusions of autologous delipidated HDL in six homozygous familial hypercholesterolemic patients was effective in promoting significant regression of low-density non-calcified coronary atheroma regression as assessed by computed coronary angiography. This therapy has received Food and Drug Administration approval. Commonwealth Serum Laboratories (CSL) has carried out a large clinical endpoint trial using an HDL complex (native apoA-I with phospholipid), and the results were negative. Our purpose is to review animal and human studies using various forms of HDL infusion therapy to promote regression of atherosclerosis. In our view, differences in results may be due to: 1) the HDL preparations used, 2) the subjects studied, and 3) the methods used to assess coronary atherosclerosis.

Massive Calcification of the Ascending Aorta Secondary to Irradiation for Hodgkin's Disease Decades Earlier in Association with Aortic Valve Stenosis

Described herein are findings in 2 men who developed massively calcified non-dilated ascending aortas decades after receiving mediastinal irradiation for treatment of Hodgkin's disease associated with aortic valve stenosis. The quantity of the intimal aortic calcium was remarkable and much greater than in other aortic conditions. The ascending aorta had to be excised in one patient in order to replace the stenotic aortic valve. The other patient underwent percutaneous transluminal aortic valve implantation.

Supravalvular Aortic Stenosis and the Risk of Premature Death Among Patients With Homozygous Familial Hypercholesterolemia

Patients with homozygous familial hypercholesterolemia (HoFH) have a high risk for premature death. Supravalvular aortic stenosis (SVAS) is a common and the feature lesion of the aortic root in HoFH. The relation between SVAS and the risk of premature death in patients with HoFH has not been fully investigated. The present study analysis included 97 HoFH patients with mean age of 14.7 (years) from the Genetic and Imaging of Familial Hypercholesterolemia in Han Nationality Study. During the median (±SD) follow-up 4.0 (±4.0) years, 40 (41.2%) participants had SVAS and 17 (17.5%) participants experienced death. The proportion of premature death in the non-SVAS and SVAS group was 7.0% and 32.5%, respectively. Compared with the non-SVAS group, SVAS group cumulative survival was lower in the HoFH (log-rank test, p <0.001). This result was further confirmed in the multivariable Cox regression models. After adjusting for age, sex, low density lipoprotein cholesterol (LDL_C)-year-score, lipid-lowering drugs, cardiovascular disease, and carotid artery plaque, SVAS was an independent risk factor of premature death in HoFH on the multivariate analysis (hazard ratio 4.45; 95% confidence interval, 1.10 to 18.12; p = 0.037). In conclusion, a significantly increased risk of premature death was observed in HoFH patients with SVAS. Our study emphasized the importance of careful and aggressive management in these patients when appropriate.

Bench to bedside defining calcific aortic valve disease: osteocardiology

INTRODUCTION

For years, calcific aortic valve disease (CAVD) was thought to be due to a degenerative process, but recent scientific discoveries have proven it to be an active process. Understanding the cellular mechanisms for the development of disease and translating the cellular changes critical in the development of calcific phenotypes. The use of multimodality imaging has been the gold standard to define the development of calcification to determine the timing of therapy.

AREAS COVERED

This review will discuss the scientific literature in a new and evolving field known as osteocardiology, which specifically defines the cellular mechanisms involved in the development of the osteogenic phenotype in the heart and vasculature. The work in this field has been highlighted by the calcific aortic valve disease working group at the NIH. This review will discuss the appropriate use criteria for multimodality imaging techniques to identify early cellular and hemodynamic disease progression in the aortic valve to help determine the timing of therapy, the osteocardiology theory.

EXPERT OPINION

The authors will provide their background in basic science and clinical medicine to support the opinions in this paper.

Aortic Valvular Disease in Elderly Subjects with Heterozygous Familial Hypercholesterolemia: Impact of Lipid-Lowering Therapy

Hypercholesterolemia and statins are risk factors for aortic stenosis (AS) and vascular calcification, respectively. Whether heterozygous subjects with familial hypercholesterolemia (HeFH) treated with statins are at risk of AS is unknown. We study the prevalence of AS, aortic valve calcification (AoVC), and aortic sclerosis (ASc) in elderly subjects with HeFH in a prolonged statin treatment. Case-control study, cases were adults ≥65 years of age with a genetic diagnosis of HeFH, LDLc >220 mg/dl, and statin treatment ≥5 years. Controls were relatives of HeFH patients, with LDLc <190 mg/dl. Participants underwent a cardiac ultrasound for aortic valve analysis. We studied 205 subjects, 112 HeFH and 93 controls, with mean age 71.8(6.5) years and 70.0(7.3) years, respectively. HeHF, with respect to controls, presented greater gradients of aortic transvalvular pressure, 7.4(7.3) mmHg versus 5.0(2.8) mmHg, and maximum aortic velocity, 1.7(0.7) m/s versus 1.5(0.4) m/s, and lower aortic valve opening area, 2.0(0.7) cm² versus 2.4(0.6) cm² (all p < 0.05). AoVC and ASc were also more prevalent in HeFH (p < 0.05 between groups). Moderate/severe AS prevalence was higher among HeFH: 7.1% versus 1.1% (age- and sex-adjusted odds ratio (OR) 8.33, p = 0.03). Independent risk factors for aortic valve disease in HeFH were age and LDLc before treatment. The number of years under statin treatment was not associated with any aortic valve measurement. Subjects ≥65 years with HeFH in prolonged statin treatment show more aortic valvular disease and higher frequency of AS than controls. Life-long elevated LDLc exposure, rather than time of exposure to statins, explains this higher risk.

Syphilitic aortitis: still a current common cause of aneurysm of the tubular portion of ascending aorta

Aortic syphilis today is infrequently diagnosed clinically. Described herein are findings in 5 women who had resection of a fusiform aneurysm of the tubular portion of ascending aorta, and examination of the wall of the aneurysm disclosed classic features of aortic syphilis. The 5 patients were among 36 who had ascending aortic operations at Baylor University Medical Center in Dallas in 2018 and early 2019. Syphilitic aneurysm in each spared the sinus portion and involved diffusely the tubular portion of ascending aorta, beginning at the sinotubular junction. The aneurysmal wall was thicker than normal because of thickening of both intima and adventitia. The latter contained foci of lymphocytes and plasmacytes and thickened and narrowed vasa vasora. The media was disrupted by fibrous scars, which weakened the integrity of the aorta. Aortitis of the tubular portion of ascending aorta in syphilis is a diffuse process, but often is mistakenly called "atherosclerosis" which, when present in this portion of aorta, can be extensive but is focal. Aortic syphilis is important to diagnose so that patients can receive antibiotic therapy to delay, prevent, or treat neurosyphilis, a common accompaniment of aortic syphilis.

Cholesterol removal from human plasma with biologically modified cryogels

In this study, low molecular weight heparin immobilized P(HEMA) cryogels were fabricated for the removal of LDL-C in hypercholesterolemic human plasma. After characterization studies for P(HEMA) cryogels, effects of the parameters including medium pH, CNBr concentration, heparin concentration and contact time on heparin immobilization were investigated. Blood compatibility and cell adhesion tests were also performed, and platelet and leucocyte loss for P(HEMA)-Hp cryogels were found to be 2.95% and 4.91%, respectively. Maximum adsorption capacity for LDL-C from hypercholesterolemic human plasma was found to be 26.7 mg/g for P(HEMA)-Hp cryogel while it was only 1.67 mg/g for bare P(HEMA) cryogel. The P(HEMA)-Hp cryogels exhibit high desorption ratios up to 96% after 10 adsorption-desorption cycles with no significant decrease in the adsorption capacity. The findings indicated that these reusable P(HEMA)-based cryogels proposed good alternative adsorbents for removal of LDL-C.

Operative Recognition of Syphilis of the Aorta

Aortic syphilis has not disappeared. Few patients with aortic syphilis are diagnosed pre-operatively or after histologic examination of the resected aortas. The gross features of the wall of the syphilitic aortic aneurysm, however, are unique allowing diagnosis of this entity on the operating table. Thirty patients aged 33 to 84 years (mean 66) (18 women) had a syphilitic aneurysm involving the tubular portion of ascending aorta resected at Baylor University Medical Center at Dallas from 2009 through 2017. That syphilis was the cause of the aneurysm was not appreciated either preoperatively or at operation. Syphilis produces characteristic changes in the aorta: it is thicker than normal due to fibrous thickening of the intima and adventitia, the intimal surface is 100% abnormal, and the sinus portion of the aorta is uninvolved. The process begins at or just distal to the sinotubular junction. Histologic findings are specific. A negative serologic test for syphilis does not rule out the presence of syphilis of the aorta. The key to identifying at operation syphilis of the aorta is to note that its entire intimal surface is abnormal, that one or more saccular aneurysms may arise from the fusiform aneurysm, that the aneurysmal wall isthicker than normal, and that the wall of the sinus portion of the aorta is spared. Identificationof the syphilitic cause appears to be important because antibiotic therapy is recommended to prevent or retard the development of neurological syphilis, particularly in the younger patients.

Partial Identification of the Average Treatment Effect Using Instrumental Variables: Review of Methods for Binary Instruments, Treatments, and Outcomes

Several methods have been proposed for partially or point identifying the average treatment effect (ATE) using instrumental variable (IV) type assumptions. The descriptions of these methods are widespread across the statistical, economic, epidemiologic, and computer science literature, and the connections between the methods have not been readily apparent. In the setting of a binary instrument, treatment, and outcome, we review proposed methods for partial and point identification of the ATE under IV assumptions, express the identification results in a common notation and terminology, and propose a taxonomy that is based on sets of identifying assumptions. We further demonstrate and provide software for the application of these methods to estimate bounds. Supplementary materials for this article are available online.

Risk factors for degenerative aortic valve disease in India: A case control study

Background

Degenerative aortic valve disease often co-exists with coronary artery disease (CAD) and studies done in western populations have shown that it shares the same risk factors which cause CAD. However little is known in this context among Asian Indians. The current study looks into the risk factors of degenerative aortic valve disease in Asian Indian population.

Methods

Ninety-one consecutive patients with severe aortic stenosis (AS) reporting for left heart catheterization prior to valve replacement surgery at a tertiary care centre were recruited for the study. They were compared with age and sex matched controls selected from a database of 3200 patients referred for elective diagnostic left heart catheterization for suspected CAD. Following traditional cardiovascular risk factors were assessed in all patients: age, gender, family history of CAD, smoking history, presence of diabetes, hypertension and dyslipidemia.

Results

The mean age of the study population was 57.8 ± 8.2 years (range, 40-80 years). Smoking, family history of CAD and hypercholesterolemia were significantly more prevalent in patients with degenerative AS compared to those with normal valves. No significant difference was noted in the presence of diabetes mellitus. On multivariate logistic regression, family history of premature CAD (OR 3.68; CI 1.38-9.78) smoking history (OR, 2.56; CI, 1.21-5.39), and raised LDL levels (OR, 5.55; CI, 2.63-11.69) were independently associated with the aortic stenosis patient cohort.

Conclusions

The study showed a significant association of cardiovascular risk factors with aortic stenosis independent of age and gender in Asian Indian patients.

Familial hypercholesterolemia supravalvular aortic stenosis and extensive atherosclerosis

Familial hypercholesterolemia is an autosomally dominant disorder caused by various mutations in low-density lipoprotein receptor genes. This can lead to premature coronary atherosclerosis and cardiac-related death. The symptoms are more severe in the homozygous type of the disease. Premature malignant atherogenesis leading to aortic root abnormalities causing supravalvular aortic stenosis is rare. Our case demonstrates the diagnostic imaging findings of the phenotype of patients who have severe elevated LDL with familial hypercolesterolemia.

Premature Valvular Heart Disease in Homozygous Familial Hypercholesterolemia

Valvular heart disease frequently occurs as a consequence of premature atherosclerosis in individuals with familial hypercholesterolemia (FH). Studies have primarily focused on aortic valve calcification in heterozygous FH, but there is paucity of data on the incidence of valvular disease in homozygous FH. We performed echocardiographic studies in 33 relatively young patients (mean age: 26 years) with homozygous FH (mean LDL of 447 mg/dL, 73% on LDL apheresis) to look for subclinical valvulopathy. Twenty-one patients had evidence of valvulopathy of the aortic or mitral valves, while seven subjects showed notable mitral regurgitation. Older patients were more likely to have aortic valve calcification (>21 versus ≤21 years: 59% versus 12.5%; p = 0.01) despite lower LDL levels at the time of the study (385 versus 513 mg/dL; p = 0.016). Patients with valvulopathy were older and had comparable LDL levels and a lower carotid intima-media thickness. Our data suggests that, in homozygous FH patients, valvulopathy (1) is present across a wide age spectrum and LDL levels and (2) is less likely to be influenced by lipid-lowering treatment. Echocardiographic studies that focused on aortic root thickening and stenosis and regurgitation are thus likely an effective modality for serial follow-up of subclinical valvular heart disease.

2D-STI combined with gated 99Tcm-MIBI MPI for the diagnosis of myocardial ischemia in hypercholesterolemia patients

This study aimed to investigate the reliability of ultrasound two-dimensional speckle tracking imaging (2D-STI) for the evaluation of myocardial ischemia in familial hypercholesterolemia (FH) patients. We recruited 28 patients clinically diagnosed with homozygous familial hypercholesterolemia (HoFH) and subjected them to 2D-STI, gated transthoracic Doppler echocardiography (TTDE), and ⁹⁹Tc^m-methoxyisobutylisonitrile myocardial perfusion imaging (⁹⁹Tc^m-MIBI MPI). The sensitivity, specificity and diagnostic accordance rate of TTDE and 2D-STI for myocardial ischemia in HoFH patients were compared with the ⁹⁹Tc^m-MIBI scores. According to the diagnosis of ischemia in the three main coronary arteries (LAD, LCX, and RCA) by MPI, patients were further divided into different groups for comparing segmental strain by 2D-STI. The total correlation between TTDE and ⁹⁹Tc^m-MIBI MPI for evaluation of myocardial ischemia was r=0.483 and between 2D-STI and ⁹⁹Tc^m-MIBI MPI was 0.786. The total correlation index for ejection fraction (EF) between TTDE and ⁹⁹Tc^m-MIBI MPI was r=0.606 and for 2D-STI and ⁹⁹Tc^m-MIBI MPI was r=0.919. TTDE indicated that differences among LVDd, LVDs, IVS, LVPW, AO Vmax, PG, E/e', and DT were statistically significant. STI indicated that the total strain of the ischemia group was lower than that of the non-ischemia group. The total systolic strain and total early diastolic strain of the ischemia group were lower than that of the non-ischemia group. TTDE can be used for primary observation and evaluation of ventricular wall ischemia for HoFH patients. Ultrasound 2D-STI is better than TTDE in the evaluation of myocardial ischemia in HoFH patients. Ultrasound 2D-STI shows the same effectiveness as ⁹⁹Tc^m-MIBI MPI for the detection of myocardial ischemia, serving as good tool for prognosis and treatment evaluation in HoFH patients.

Homozygous familial hypercholesterolemia: Summarized case reports

BACKGROUND AND AIMS

Homozygous familial hypercholesterolemia (hoFH) is a rare genetic disorder with potential severe atherosclerosis in the pediatric age.

METHODS

We report on 9 patients with hoFH, who had been diagnosed within the last 30 years and who were consequently treated with apheresis and drugs.

RESULTS

Two deaths occurred: one at age 36 years and the other at age four and a half years before effective treatment was commenced. All other patients are still in good clinical condition today, although four of them have proven aortic stenosis or arterial plaques.

CONCLUSIONS

Our case report highlights that adequate treatment should start as early as possible to delay the onset of clinical manifestations of atherosclerosis. It can be assumed that the introduction of new drugs can improve the outcome and possibly lengthen the life expectancy of patients affected by hoFH.

HtrA2 suppresses autoimmune arthritis and regulates activation of STAT3

Rheumatoid arthritis (RA) is an autoimmune disease that is related to the induction of T helper (Th)17 cells, which secrete interleukin-17, and activation of the signal transducer and activator of transcription (STAT) 3. The expression of high-temperature requirement protein A (HtrA) 2, a serine protease involved in apoptosis, was decreased in RA patients nonresponsive to drug treatment of RA. The aim of this study was to determine whether overexpression of HtrA2 has a therapeutic effect on RA. Th17 differentiation, osteoclastogenesis, and lymphocyte activation are increased in motor neuron degeneration (mnd)2 mice, which lack HtrA2 activity because of a missense mutation (Ser276Cys) in the protease domain of HtrA2. The inhibitor of HtrA2 also increased Th17 differentiation. On the other hand, HtrA2 induced cleavage of STAT3 and overexpression of HtrA2 attenuated CIA in a mouse model. HtrA2 overexpression inhibited plaque development as well as the differentiation of Th17 in ApoE^-/- mice after immunization with proteoglycans to induce a hyperlipidemia-based RA animal model. The therapeutic function of HtrA2 in inflammatory diseases is linked with Th17 development and the STAT3 pathway in splenocytes. These results suggest that HtrA2 participates in immunomodulatory activity where the upregulation of HtrA2 may shed light on therapeutic approaches to RA and hyperlipidemia.

Massive Diffuse Calcification of the Ascending Aorta and Minimal Focal Calcification of the Abdominal Aorta in Heterozygous Familial Hypercholesterolemia

A 41-year-old woman, the mother of 3 offspring, with likely heterozygous familial hypercholesterolemia, had been asymptomatic until age 38 when angina pectoris and exertional dyspnea appeared leading to the discovery of severe multivessel coronary artery disease and a massively calcified ascending aorta. Coronary bypass grafting using the right and left internal mammary arteries did not alleviate the symptoms. Evidence of overt heart failure subsequently appeared and that led to heart transplantation at age 41. She died 22 days later. The occurrence of massive diffuse calcification of the ascending aorta and minimal focal calcification of the abdominal aorta is rare and in the patient described it appears to be the consequence of heterozygous familial hypercholesterolemia.

The genetics of familial hypercholesterolemia and emerging therapies

Familial hypercholesterolemia (FH) results in very high levels of atherogenic low-density lipoprotein (LDL) cholesterol from the time of birth. Mutations of the genes encoding for the LDL receptor, apolipoprotein B and proprotein convertase subtilisin/kexin type 9, are causes for this autosomal dominant inherited condition. Heterozygous FH is very common, while homozygous FH is rare. Affected individuals can experience premature cardiovascular disease; most homozygous patients experience this before the age of 20 years. Since effective LDL cholesterol lowering therapies are available, morbidity and mortality are decreased. The use of statins is the first choice in therapy; combining other lipid-lowering medications is recommended to lower LDL cholesterol sufficiently. In some cases, lipoprotein apheresis is necessary. In heterozygous FH, these measures are effective to lower LDL cholesterol, but in severe cases and in homozygous FH there remains an unmet need. Emerging therapies, such as the recently approved microsomal triglyceride transfer protein inhibitor and the apolipoprotein B antisense oligonucleotide, might offer further options for these patients with very high cardiovascular risk. Early diagnosis and early treatment are important to reduce cardiovascular events and premature death.

Calcific Aortic Valve Disease: Molecular Mechanisms and Therapeutic Approaches

Calcification occurs in atherosclerotic vascular lesions and In the aortic valve. Calcific aortic valve disease (CAVD) is a slow, progressive disorder that ranges from mild valve thickening without obstruction of blood flow, termed aortic sclerosis, to severe calcification with impaired leaflet motion, termed aortic stenosis. In the past, this process was thought to be 'degenerative' because of time-dependent wear and tear of the leaflets, with passive calcium deposition. The presence of osteoblasts in atherosclerotic vascular lesions and in CAVD implies that calcification is an active, regulated process akin to atherosclerosis, with lipoprotein deposition and chronic inflammation. If calcification is active, via pro-osteogenic pathways, one might expect that development and progression of calcification could be inhibited. The overlap in the clinical factors associated with calcific valve disease and atherosclerosis provides further support for a shared disease mechanism. In our recent research we used an in vitro porcine valve interstitial cell model to study spontaneous calcification and potential promoters and inhibitors. Using this model, we found that denosumab, a human monoclonal antibody targeting the receptor activator of nuclear factor-κB ligand may, at a working concentration of 50 μg/mL, inhibit induced calcium deposition to basal levels.

Familial hypercholesterolemia: A review

Familial hypercholesterolemia (FH) is a genetic disorder of lipoprotein metabolism resulting in elevated serum low-density lipoprotein (LDL) cholesterol levels leading to increased risk for premature cardiovascular diseases (CVDs). The diagnosis of this condition is based on clinical features, family history, and elevated LDL-cholesterol levels aided more recently by genetic testing. As the atherosclerotic burden is dependent on the degree and duration of exposure to raised LDL-cholesterol levels, early diagnosis and initiation of treatment is paramount. Statins are presently the mainstay in the management of these patients, although newer drugs, LDL apheresis, and other investigational therapies may play a role in certain subsets of FH, which are challenging to treat. Together these novel treatments have notably improved the prognosis of FH, especially that of the heterozygous patients. Despite these achievements, a majority of children fail to attain targeted lipid goals owing to persistent shortcomings in diagnosis, monitoring, and treatment. This review aims to highlight the screening, diagnosis, goals of therapy, and management options in patients with FH.

Severe Hypercholesterolemia: A Unique Presentation of Non-Hodgkin's Lymphoma in a Patient with Neurofibromatosis Type 1

We report a case of non-Hodgkin's lymphoma (NHL) with an unusual initial manifestation as severe hypercholesterolemia and obstructive jaundice in a patient with neurofibromatosis type 1 (NF 1). NHL should be considered in the evaluation of obstructive jaundice alone or in combination with severe hypercholesterolemia. Relief of biliary obstruction led to the resolution of hypercholesterolemia in our 59-year-old male patient, followed by doxorubicin-based chemotherapy for the underlying lymphoma. NF 1 is a genetic condition that results from a defect in a tumor-suppressor gene and it is likely that this led to the development of NHL in our patient. It is important that clinicians are familiar with the gastrointestinal manifestations of NF 1, especially its association with intra-abdominal malignancies, when treating patients with a personal or family history. To the best of our knowledge, this is the first case of NHL presenting initially as severe hypercholesterolemia and it is also one of the few instances where NHL has been reported in association with NF 1.

The severe hypercholesterolemia phenotype: clinical diagnosis, management, and emerging therapies

The severe hypercholesterolemia phenotype includes all patients with marked elevation of low-density lipoprotein cholesterol (LDL-C) levels. The most common cause is autosomal dominant hypercholesterolemia, an inherited disorder caused by mutations either in LDL receptor, apolipoprotein B (APOB), or proprotein convertase subtilisin kexin type 9 (PCSK9) genes. However, it is now known that many subjects with severe inherited hypercholesterolemia have no defects in these genes. These cases are caused either by mutations in genes yet to be identified or are consequences of polygenic, epigenetic, or acquired defects. Because the clinical consequences of extreme hypercholesterolemia are the same no matter the cause, the focus should be on the identification of subjects with severe hypercholesterolemia, followed by phenotypic screening of family members. Genetic screening is not necessary to diagnose or initiate treatment for the severe hypercholesterolemia phenotype. Management of severe hypercholesterolemia is based on risk factor modification and use of multiple lipid-lowering medications. Lipoprotein apheresis is indicated for coronary artery disease (CAD) patients taking maximally tolerated therapy and with LDL-C levels >200 mg/dl (>300 mg/dl if without CAD). A microsomal triglyceride transfer protein inhibitor and an antisense oligonucleotide against APOB have recently been approved for use in subjects with clinically diagnosed homozygous familial hypercholesterolemia. PCSK9 inhibitors, currently in phase II and III trials, lower LDL-C up to an additional 70% in the setting of maximally tolerated medical therapy and have the potential to reduce LDL-C to <70 mg/dl in most patients. Early identification of affected individuals and aggressive treatment should significantly reduce the burden of cardiovascular disease in society.

Surgical treatment of valvular and supravalvular aortic stenosis in homozygous familial hypercholesterolemia

A 61-year-old male with homozygous familial hypercholesterolemia presented with dyspnea and syncope. He had been treated with low-density lipoprotein apheresis for 26 years. Echocardiography and computed tomography showed severe valvular and supravalvular aortic stenosis. Computed tomography and cardiac catheterization revealed a severely calcified narrowed aortic root and an occlusion in the proximal right coronary artery. During surgery, the ascending aorta was replaced under deep hypothermic circulatory arrest without aortic cross-clamping. After that, the aortic root from the annulus to the sino-tubular junction was enlarged with a two-ply bovine pericardial patch. An aortic valve replacement with a 17 mm mechanical valve and coronary artery bypass grafting to the right coronary artery were performed. The patient recovered from the surgery without any cerebrovascular complications.

Dietary cholesterol increases ventricular volume and narrows cerebrovascular diameter in a rabbit model of Alzheimer's disease

Using structural magnetic resonance imaging in a clinical scanner at 3.0T, we describe results showing that following 12weeks on a diet of 2% cholesterol, rabbits experience a significant increase in the volume of the third ventricle compared to rabbits on a diet of 0% cholesterol. Using time-of-flight magnetic resonance angiography, we find cholesterol-fed rabbits also experience a decrease in the diameter of a number of cerebral blood vessels including the basilar, posterior communicating, and internal carotid arteries. Taken together, these data confirm that, despite the inability of dietary cholesterol to cross the blood-brain barrier, it does significantly enlarge ventricular volume and decrease cerebrovascular diameter in the rabbit - effects that are also seen in patients with Alzheimer's disease.

A young male with familial hypercholesterolemia

A nine-year-old Bangladeshi male with a body mass index 16.5 kg/m(2) presented with progressive tuberous xanthomata on both auricles, elbows, gluteal regions and legs since birth. His father, paternal and maternal grandfather had xanthelasma, however, the siblings had none. Examination of the cardiovascular system was otherwise normal. Laboratory investigations were performed on several occasions since he was 4 years of age and revealed extreme dyslipidaemia with very high total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), triglycerides (TG), apolipoprotein B (Apo-B) and lipoprotein(a), and low apolipoprotein-A (Apo-A) levels. Repeated combination of lipid lowering agents with cholestyramine, atorvastatin and ezetimibe were virtually ineffective in improving the lipid profiles. Supplementation therapy with niacin also had no effect. In view of the unavailability in Bangladesh of lipid apheresis, the cornerstone of therapy, the management of the case becomes complicated.

Chest pain with elevated troponin assay in adolescents

OBJECTIVE

We sought to describe the evaluation, treatment, and follow-up of adolescents who presented to a single institution with chest pain and an elevated troponin I value in the absence of typical symptoms of pericarditis or myocarditis. Materials and methods We performed a retrospective review of patients in the age group of 10-18 years of age with no history of significant heart disease admitted to our institution from 2000 to 2010 after presenting with chest pain and an elevated troponin I value.

RESULTS

A total of 16 patients were identified with a median age of 16.5 years (range 11.2-17.8 years). Of these 13 (81%) were male and 10 (63%) showed evidence of localised ST elevations on electrocardiogram. The median peak troponin I level was 17.8 nanograms per millilitre (range 0.89-227, normal less than 0.4). There were eight patients (50%) with a diagnosis of coronary vasospasm, three patients (20%) with atypical myopericarditis, one patient with coronary anomaly, one patient with hypercoagulable disorder, and one patient with prolonged supraventricular tachycardia. In two patients, no definitive diagnosis was made. There was one patient who needed catheter-based intervention, which involved stenting of a coronary artery after a procedure-related complication.

CONCLUSIONS

In our cohort of adolescents without history of significant cardiac disease, chest pain and elevated troponin I levels were attributed to a variety of causes. Although coronary vasospasm and atypical myopericarditis were seen most commonly, coronary anomaly was identified in one case. Magnetic resonance imaging proved a useful diagnostic tool to assess coronary artery anatomy and myocardial changes suggestive of myocarditis. On the basis of these results and a review of the literature, a general evaluation algorithm is presented.

Adeno-associated virus serotype 8 gene therapy leads to significant lowering of plasma cholesterol levels in humanized mouse models of homozygous and heterozygous familial hypercholesterolemia

Familial hypercholesterolemia (FH) is a life-threatening genetic disease caused by mutations in the gene encoding low-density lipoprotein receptor (LDLR). As a bridge to clinical trials, we generated a "humanized" mouse model lacking LDLR and apolipoprotein B (ApoB) mRNA editing catalytic polypeptide-1 (APOBEC-1) expression and expressing a human ApoB100 transgene in order to permit more authentic simulation of in vivo interactions between the clinical transgene product, human LDLR (hLDLR), and its endogenous ligand, human ApoB100. On a chow diet, the humanized LDLR-deficient mice have substantial hypercholesterolemia and a lipoprotein phenotype more closely resembling human homozygous FH (hoFH) than in previous mouse models of FH. On injection of an adeno-associated virus serotype 8 (AAV8) vector encoding the human LDLR cDNA, significant correction of hypercholesterolemia was realized at doses as low as 1.5 × 10(11) genome copies (GC)/kg. Given that some patients with heterozygous FH (heFH) cannot be adequately treated with current therapy, we then extended our studies to similarly "humanized" mice that were heterozygous for LDLR deficiency, and that have a lipoprotein phenotype resembling heterozygous FH. Injection of AAV8-hLDLR brought about significant reduction in total and LDL cholesterol at doses as low as 5 × 10(11) GC/kg. Collectively, these data demonstrate the safety and efficacy of the liver-specific AAV8-hLDLR vector in the treatment of humanized mice modeling both hoFH and heFH.

Fatal cardiac atherosclerosis in a child 10 years after liver transplantation: a case report and a review

We hereby review liver transplantation for homozygous familial hypercholesterolemia and report the case of a 14-year-old girl presenting with severe bilateral coronary ostial stenosis and tight supra-valvular aortic narrowing 10 years after liver transplantation. Despite normalization of the lipids after liver transplantation, the patient showed evidence of severe cardiac atherosclerosis 10 years later and died of apparent sepsis.

Atherosclerotic lesions in mouse and man: is it the same disease?

PURPOSE OF REVIEW

Genetically-engineered mice with hyperlipidemia are the most widely used atherosclerosis models today, but recent advances in transgenesis open the possibility to create new models in alternative species, such as the rat and pig. It seems relevant at this point in time to review some of the strengths and weaknesses of the mouse.

RECENT FINDINGS

The histology of lesion development in mouse and man has more similarities than differences, and comparative genetics show that many mechanisms of murine and human atherogenesis are shared. Unfortunately, the most feared complication of human atherosclerosis, that is, plaque rupture and thrombosis, occur extremely rarely in mice. This is a major problem. Most patients today are not treated before symptoms ensue, and at this late stage of the disease, mechanisms identified during plaque development in the mouse may not be very important.

SUMMARY

Murine atherosclerosis models are highly valuable for identifying atherogenic mechanisms that can be targeted by preventive medicine. However, models with thrombotic complications and large animal models suitable for interventional procedures and imaging would be more supportive for current clinical practice and are highly wanted.

Relationships of mitral annular calcification to cardiovascular risk factors: the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

Mitral annular calcification (MAC) is a fibrous, degenerative calcification of the mitral valve. The relationship between MAC and cardiovascular disease (CVD) risk factors is not well defined. Thus, we performed a cross-sectional study to determine which CVD risk factors are independently associated with MAC in the Multi-Ethnic Study of Atherosclerosis (MESA).

METHODS

MESA includes 6814 women and men ages 45-84 years old without apparent CVD in 4 ethnic groups (12% Chinese, 38% Caucasian, 22% Hispanic, and 28% African American). MAC was defined by presence of calcium in the mitral annulus by cardiac computed tomography at enrollment. Multivariable logistic regression was used to evaluate relationships between MAC and CVD risk factors.

RESULTS

The overall prevalence of MAC was 9%. The prevalence of MAC was highest in Caucasians (12%), followed by Hispanics (10%), African Americans (7%) and was lowest in Chinese (5%). Characteristics associated with MAC included age (p<0.01), female gender (p<0.01), increased body mass index (BMI) (p=0.03), and former smoking status (p<0.008). The MAC group had a higher prevalence of hypertension, diabetes mellitus (DM), and family history of heart attack (all p<0.001). After adjusting for all variables, age, female gender, diabetes mellitus, and increased BMI remained strongly associated with MAC.

CONCLUSIONS

Age, female gender, DM, and increased BMI were significantly associated with MAC. Prevalence of MAC was strongly associated with female gender and increasing age in all ethnicities.

Nutraceuticals in the early infancy

Atherosclerosis disease and its extent in childhood correlate positively with established risk factors, namely obesity, hypercholesterolemia, diabetes mellitus, and hypertension. The safety and efficacy of some dietary interventions to modulate risk factors in childhood are documented by an increasing body of evidence. The present review analyzes nutritional and nutraceutical current strategies addressed to modify some risk factors of atherosclerosis in childhood. In particular, studies concerning nutrients such as fibers, omega-3-fatty acids, vitamin D, antioxidants, and calcium have been evaluated. An overall analysis suggests that some nutraceuticals might represent an attractive tool to lower the development of atherosclerotic-related cardiovascular complication in children. Nevertheless, at this moment, due to the methodological weakness that characterizes the majority of the analyzed studies, nutrients or supplements should not be considered as a therapeutic tool potentially usable for clinical purpose in children at risk for cardiovascular disease.

Relationship between platelet indices and aortic valve sclerosis

OBJECTIVE

Aortic valve sclerosis (AVS) is a progressive disease that is characterized by aortic valve thickening without causing significant narrowing and in which pathology resembles atherosclerotic coronary heart disease. We aimed to evaluate the relationship between AVS and platelet indices including mean platelet volume (MPV), platelet distribution weight (PDW), and platelet count.

METHOD

Two hundred ten patients who were evaluated in the echocardiography unit due to various reasons between January and October 2008 were consecutively included in the study. The patients were divided into 2 groups according to presence or absence of AVS. The patient group consisted of 150 patients (76 females and 74 males; mean age, 64.5 + or - 11.5 years). Patients without AVS (24 females and 36 males; mean age, 49.8 + or - 15.7 years) were assigned as control group. The MPV, PDW, and platelet count were measured.

RESULTS

The MPV (9.56 + or - 1.3 fL vs 9.15 + or - 1.0 fL, P = .022) and PDW (16.9 + or - 2.3% vs 14.9 +/- 2.3, P = .001) were significantly higher in patients with AVS (+) compared to the AVS (-) group. No significant difference was demonstrated between the groups in terms of white blood cell and platelet counts (P > .05). When the AVS (+) group was compared to the AVS (-) group, a significant difference was found in respect of hypertension, diabetes mellitus, and smoking status.

CONCLUSION

Platelet production indices including MPV and PDW were increased in patients with AVS. The complex interrelationship between increased platelet production indices and AVS and value of antithrombotic therapies in patients with AVS need to be evaluated in further studies.

The challenge produced by familial homozygous hypercholesterolemia when treating premature coronary arterial disease in the young

BACKGROUND

Familial hypercholesterolemia is a monogenic, autosomal dominant disorder caused by mutations in the LDL receptor gene. Familial homozygous hypercholesterolemia results when both the alleles have the defective mutation. It is characterized by cutaneous and tendinous xanthomas, premature corneal arcing, and is associated with an increased risk of coronary arterial disease. It is also seriously underdiagnosed, resulting in delayed treatment.

METHODS

We present a cross-sectional study of 5 patients with familial homozygous hypercholesterolemia who presented to the department of cardiology at Sri Jayadeva Institute of Cardiology, Bangalore, India. All of them underwent coronary angiography as part of the investigation of their angina.

RESULTS

All 5 patients were in 2nd or 3rd decade of life, 4 being male, and 4 presenting with effort angina, the other having unstable angina. All had multiple tendinous xanthomas. The majority had significant high grade coronary arterial stenosis. Coronary arterial bypass grafting was necessary in 3, with the others undergoing percutaneous insertion of coronary arterial stents.

CONCLUSION

Familial homozygous hypercholesterolemia is a potentially dangerous risk factor that can result in premature coronary arterial disease in children and young adults. This can result in severe morbidity and premature death in young individuals. We also emphasise the need to screen first-degree relatives and extended family members, this playing an important role in early detection and treatment. Despite recent advances in treatment using lipid lowering agents, the disease remains a significant challenge.

Aortic calcifications in familial hypercholesterolemia: potential role of the low-density lipoprotein receptor gene

BACKGROUND

We have previously reported premature, extensive aortic calcifications in patients with homozygous familial hypercholesterolemia (hmzFH) due to mutations in the low-density lipoprotein receptor gene (LDL-R). The objective of this study was to measure the degree of aortic calcification in heterozygous FH (htzFH) compared to both hmzFH and controls. We hypothesized that the LDL-R gene may contribute to aortic calcifications in a gene-dosage effect.

METHOD

Patients with htzFH due to the French Canadian mutation (Delta15 kb del. null allele) were selected. All patients underwent computed tomographic scan to measure vascular calcification. We used 22 hmzFH patients from our previous study and patients undergoing computed tomographic virtual colonoscopy as controls.

RESULTS

Mean age for htzFH was 50 +/- 15 years; initial cholesterol level before treatment was 10.45 +/- 1.73 mmol/L. Major cardiovascular events occurred in 9 of 17 patients. A strong correlation between age and calcium score was found (r = 0.72, P = .0016). There was a strong correlation between the cholesterol-year score (an index of lifelong cholesterol burden) and the aortic calcium score (r = 0.62, P = .0105). Aortic calcifications in htzFH subjects occurred later than in hmzFH patients, but much earlier than in controls, suggesting a gene-dosage effect of LDL-R mutations and aortic calcium deposition.

CONCLUSION

Aortic calcification was observed in patients with htzFH but presented at a later time and were less extensive than in hmzFH (34 vs 14 years, respectively). Because aortic calcifications may be partly independent of serum cholesterol levels in patients with familial hypercholesterolemia, implications for screening and the timing of treatment initiation may need reassessment.

Calcific aortic stenosis: lessons learned from experimental and clinical studies

Calcific aortic stenosis is the most common indication for surgical valve replacement in the United States. For years this disease has been described as a passive degenerative process during which serum calcium attaches to the valve surface and binds to the leaflet to form nodules. Therefore, surgical treatment of this disease has been the approach toward relieving outflow obstruction in these patients. Recent studies demonstrate an association between atherosclerosis and its risk factors for aortic valve disease. In 2008, there are increasing number of epidemiology and experimental studies to provide evidence that this disease process is not a passive phenomena. There is an active cellular process that develops within the valve leaflet and causes a regulated bone formation to develop. If the atherosclerotic hypothesis is important in the initiation of aortic stenosis, then treatments used in slowing the progression of atherosclerosis may be effective in patients with aortic valve disease. This review will discuss the pathogenesis and the potential for medical therapy in the management of patients with calcific aortic stenosis by examining the lessons provided from the experimental research.

A case of obstructive jaundice with severe hypercholesterolemia probably due to lipoprotein-Y

AIM

We analyzed the lipoproteins of a patient with pancreatic cancer causing obstructive jaundice, with marked hypercholesterolemia.

METHODS

The patient was a 49-year-old female. Serum total cholesterol, triglyceride, LDL-cholesterol and HDL-cholesterol levels were 1,170 mg/dL, 282 mg/dL, 1,070 mg/dL and 53 mg/dL, respectively. Cholesterol ester and lecithin:cholesterol acyltransferase decreased, and so-called remnant like particle-cholesterol increased remarkably.

RESULTS

Fractionation of the patient's serum by polyacrylamide gel disc electrophoresis showed an abundant VLDL fraction, whereas agarose gel electrophoresis demonstrated a high level of beta-lipoprotein. Sepharose 6B gel filtration of the serum revealed that the levels of free cholesterol and apolipoprotein B were high in the VLDL- corresponding fraction.

CONCLUSION

The results suggested that the high cholesterol level was due to the presence of abnormally large particles rich in free cholesterol and apoB, and this abnormal fraction may correspond to lipoprotein-Y that was increased in obstructive jaundice.

Severe hypercholesterolemia mediated by lipoprotein X in a pediatric patient with chronic graft-versus-host disease of the liver

We describe a case of extreme hypercholesterolemia, mediated by lipoprotein X, in a 12-year-old Caucasian female who underwent an unrelated allogenic bone marrow transplant for relapsed acute myelocytic leukemia (AML). Her post-transplant course was complicated by severe chronic graft-versus-host disease (GVHD) of the liver. Previously normal serum cholesterol and triglycerides rose to 1,122 mg/dl (29.0 mmol/L) and 1,100 mg/dl (12.4 mmol/L), respectively. Serum cholesterol appeared to be dominantly carried by lipoprotein X. Intra-hepatic cholestasis leading to reflux of bile lipoproteins into the blood stream and subsequent formation of lipoprotein X appears to be the mechanism underlying this phenomenon.