Optimal management of familial hypercholesterolemia: treatment and management strategies

The effect of preoperative statins on postoperative mortality, renal, and neurological complications in patients undergoing cardiac surgeries: a retrospective cohort study

BACKGROUND

Cardiac surgery is performed worldwide to treat severe cases of cardiovascular diseases. Statins have shown controversial effects on complications after cardiac surgeries. We aimed to investigate the effect of preoperative statin therapy on the frequency of postoperative mortality, renal, and neurological complications.

METHODS

In a retrospective cohort study, the database of patients operated on in two hospitals in southern Iran during 2008-2019 was used to compare preoperative statin use with no use on the composite outcome of mortality, renal, and neurological complications as well as on each component of the composite, separately. Effects of low dose (<40 mg simvastatin equivalence) vs. high dose (≥40 mg) statins were also evaluated. Confounders that could affect the outcomes were considered in the logistic regression model, and multiple imputation techniques were used to categorize patients with unknown statin dose use as either high or low-dose users.

RESULTS

Of total 7329 patients, 17.6% of statin users and 17% of non-statin users developed the composite outcome (P=0.51). Statin use had no statistically significant association with the composite outcome (aRR 1.01 [95% CI: 0.88-1.16]). There was no significant association with mortality [aRR: 0.75 (95% CI: 0.34-1.69)], neurological [aRR: 1.25 (95% CI: 0.77-2.12)], or renal complications [aRR: 1.03 (95% CI 0.90-1.19)] after surgery. Neither low nor high doses had any statistically significant effect on the composite or any of its components.

CONCLUSIONS

In this large study, preoperative statin use, either high dose or low dose, did not affect short-term postoperative mortality, neurological, or renal complications.

Use of Longitudinal Strain Bull’s-Eye Plot by Speckle Tracking Echocardiography for Evaluation of Homozygous Familial Hypercholesterolemia with Myocardial Ischemia

Background: In recent years, two-dimensional speckle tracking echocardiography (2D-STE) has been increasingly used to detect left ventricular myocardial ischemia with high accuracy for a reliable and comprehensive assessment of myocardial function by myocardial strain analysis. The present study aimed to assess whether the longitudinal strain (LS) bull’s eye plot could accurately detect left ventricular myocardial ischemia in homozygous familial hypercholesterolemia (HoFH) patients. Methods: A total of 28 HoHF patients, who underwent 2D-STE and myocardial perfusion imaging (MPI), were classified into two groups as diagnosed by MPI for myocardial ischemia. The myocardial ischemia score by MPI, LS bull’s-eye plot, and strain parameters were analyzed and compared. Results: Among the 28 HoFH patients, MPI detected 30.77% and 2D-STE showed 30.19% ischemic segments in 13 and 15 HoFH patients with myocardial ischemia, respectively. All segmental LSs in the left anterior descending artery (LAD) perfusion territory were significantly decreased in patients with myocardial ischemia. The diagnostic capability of 2D-STE for myocardial ischemia was 85.29%, 95.34%, and 93.91% for sensitivity, specificity and accuracy, respectively. Conclusion: Left ventricular LS bull’s-eye plot can assist rapid and accurate evaluation of myocardial ischemia in HoFH patients. The myocardial ischemia is mainly distributed in the LAD perfusion territory in these patients.

The Effect of Mipomersen in the Management of Patients with Familial Hypercholesterolemia: A Systematic Review and Meta-Analysis of Clinical Trials

Background: Familial hypercholesterolemia (FH) lead to significant adverse effects in coronary arteries. Mipomersen is a second-generation antisense oligonucleotide that inhibits the synthesis of apolipoprotein B-100, an essential component of low density lipoprotein (LDL), and thus decreases the production of LDL. We aimed to determine the effect of mipomersen in patients with FH. Methods: We searched Ovid Medline, Ovid EMBASE, WHO ICTRP search portal, ISI database, the reference lists of relevant articles, and also Google Scholar to retrieve articles. All randomized controlled trials (RCTs) comparing patients with FH receiving mipomersen as an add-on and a parallel group receiving a placebo or no intervention were selected. Results: Five studies with more than 500 patients were included. All had low risk of bias. Pooling data showed that mipomersen probably reduces LDL compared with placebo [mean difference: −24.79, 95% CI (−30.15, −19.43)] but with a moderate level of certainty. There was a high level of evidence for injection site reactions [RR = 2.56, CI (1.47–4.44)] and a low level for increased serum alanine transaminase (ALT) > 3 times upper limit of normal (ULN) [RR = 5.19, CI (1.01–26.69)]. Conclusion: A moderate level of evidence in decreasing serum LDL indicates that we are uncertain if this drug provides benefit in any outcome important to patients. Although a low level of evidence for an increase in serum ALT leaves uncertainty about this adverse effect, injection site reactions in 10% or more of patients can be an important concern.

The curative treatment of familial hypercholesterolemia: Liver transplantation

BACKGROUND

Familial hypercholesterolemia (FH) is an autosomal dominant genetic disorder characterized by premature mortal cardiovascular complications. Liver transplantation (LT) is the only curative treatment option. In this study, the long-term clinical follow-up data of 8 patients who underwent LT with a diagnosis of FH in our center are presented.

MATERIALS AND METHODS

A total of 638 LT were performed between December 1985 and June 2019 at Baskent University, of which 8 patients underwent LT with a diagnosis of FH and were evaluated retrospectively.

RESULTS

Of the 8 patients, 4 underwent deceased donor and 4 living donor transplantation. Five patients had preoperative cardiovascular disease and consequent interventional operations. There was significant reduction in postoperative LDL-C and TC levels starting from the first week, and stabilizing at the first month and first year. The median survival time of patients was 5 years (2-12 years). All patients are still alive. None of the complications of patients with preoperative cardiovascular complications had progressed.

CONCLUSION

Liver transplantation is the preferred curative treatment for the pathophysiology of FH. In our study, LDL-C levels were brought under control with LT performed on patients with FH. Median 5-year follow-up of patients showed that the progression of cardiac complications was abated.

Intracellular cholesterol accumulation and coenzyme Q10 deficiency in Familial Hypercholesterolemia

Familial Hypercholesterolemia (FH) is an autosomal co-dominant genetic disorder characterized by elevated low-density lipoprotein (LDL) cholesterol levels and increased risk for premature cardiovascular disease. Here, we examined FH pathophysiology in skin fibroblasts derived from FH patients harboring heterozygous mutations in the LDL-receptor. Fibroblasts from FH patients showed a reduced LDL-uptake associated with increased intracellular cholesterol levels and coenzyme Q₁₀ (CoQ₁₀) deficiency, suggesting dysregulation of the mevalonate pathway. Secondary CoQ₁₀ deficiency was associated with mitochondrial depolarization and mitophagy activation in FH fibroblasts. Persistent mitophagy altered autophagy flux and induced inflammasome activation accompanied by increased production of cytokines by mutant cells. All the pathological alterations in FH fibroblasts were also reproduced in a human endothelial cell line by LDL-receptor gene silencing. Both increased intracellular cholesterol and mitochondrial dysfunction in FH fibroblasts were partially restored by CoQ₁₀ supplementation. Dysregulated mevalonate pathway in FH, including increased expression of cholesterogenic enzymes and decreased expression of CoQ₁₀ biosynthetic enzymes, was also corrected by CoQ₁₀ treatment. Reduced CoQ₁₀ content and mitochondrial dysfunction may play an important role in the pathophysiology of early atherosclerosis in FH. The diagnosis of CoQ₁₀ deficiency and mitochondrial impairment in FH patients may also be important to establish early treatment with CoQ₁₀.

Homozygous Familial Hypercholesterolemia: Anesthetic Challenges and Review of Literature

Homozygous familial hypercholesterolemia (HoFH; Fredrickson IIa) is a rare autosomal dominant hereditary disease associated with increased low-density lipoprotein cholesterol. We hereby report anesthetic challenges in a rare case of HoFH having severe progressive aortic stenosis, mitral regurgitation, diffuse aortic and carotid vessel involvement, and severe left ventricular dysfunction. The patient underwent a Konno aortoventriculoplasty with mechanical prosthesis along with mitral valve repair.

Lipid profiles of donors and recipients of liver transplant: like father like son

BACKGROUND/PURPOSE

Dyslipidemia is common in liver transplant recipients. This retrospective study investigates whether donors play a role.

METHODS

Prospectively collected data of donors and recipients of deceased-donor liver transplantation (DDLT) and living-donor liver transplantation (LDLT) were reviewed. Total cholesterol, triglyceride, low-density lipoprotein, high-density lipoprotein (HDL) and fasting glucose were compared between groups. HDL ≥1.6 mmol/L at 2 years after transplant was considered the marker of a favorable post-transplant lipid profile in recipients. Univariate and multivariate analyses were performed to identify predictive factors for this marker.

RESULTS

There were 85 DDLTs and 80 LDLTs. LDLT donors were younger (30 vs. 50 years, p < 0.001) and lighter (58.2 vs. 63.4 kg, p = 0.008) and had a lower body mass index (21.2 vs. 23.7, p < 0.001). The DDLT group had more fatty grafts (p = 0.001) and longer cold (375 vs. 103.5 min, p < 0.001) and warm (50.5 vs. 46 min, p = 0.034) ischemia. LDLT donors had lower fasting glucose (4.85 vs. 7.21 mmol/L, p < 0.001) and triglyceride (0.87 vs. 1.22 mmol/L, p = 0.016) but higher HDL (1.58 vs. 1.39 mmol/L, p = 0.022). LDLT recipients also had higher HDL at 1 year (1.48 vs. 1.28 mmol/L, p = 0.026) and 2 years (1.43 vs. 1.21 mmol/L, p = 0.008). Fourteen (16.5%) DDLT recipients and 27 (33.8%) LDLT recipients had HDL ≥1.6 mmol/L at 2 years. On multivariate analysis, donor HDL ≥1.6 mmol/L (RR 4.311, 95% CI 1.666-11.158, p = 0.003) and recipient body mass index <24 (RR 2.753, 95% CI 1.064-7.127, p = 0.037) were the two independent predictive factors.

CONCLUSION

LDLT recipients had better lipid profiles than DDLT recipients. The feature of high HDL level in donors was transferred to recipients.

Liver transplantation for homozygote familial hypercholesterolemia: the only curative treatment

FH is an autosomal dominant genetic disorder characterized by increased TC and LDL level, which leads to xanthomas, atherosclerosis, and cardiac complications even in childhood. The treatment options are diet, medical treatment, lipid apheresis, and LT. The aim of our study was to analyze our data of patients with FH. Between 2004 and 2015, there were 51 patients who underwent pediatric LT at our center. All patients with FH were identified, and the data were retrospectively analyzed. There were eight patients with homozygous FH in the median age of 10 years (IQR 6-12) who underwent LT. The median pre-operative TC and LDL levels were 611 mg/dL (IQR: 460-844) and 574 mg/dL (IQR: 398-728) and decreased to normal levels 1 week after LT (TC: 193 mg/dL and LDL: 141 mg/dL). Two patients died two and 18 months after LT due to sudden cardiac arrest. Both patients were diagnosed with cardiovascular disease pre-operatively. The LT is the only curative treatment for this disease. To achieve an excellent outcome, it should be performed before the development of cardiovascular disease, because the regression of severe cardiovascular disease after transplantation is limited.

Panvascular Disease in Familial Hypercholesterolaemia Treated with Endovascular Simultaneous Bilateral Carotid Stenting

Familial Hypercholesterolaemia (FH) is a monogenic autosomal dominant disorder affecting 1 in 500 individuals. We report a case of 32-year-old female with FH, previously not on any treatment, who presented with recurrent bilateral Middle Cerebral Artery (MCA) territory strokes and dyspnoea on exertion due to severe panvascualar disease involving descending aorta, innominate, subclavian, common carotid, internal carotid and coronary vessels. Her complete clinical work up was done and was started on lipid lowering drug treatment and low calorie diet. She underwent simultaneous bilateral carotid stenting followed by coronary artery bypass surgery at a later date. In the present scenario we want to emphasize the importance of early detection and treatment of individuals with FH, failing of which results in premature and accelerated atherosclerosis causing multisystemic vascular disease with significant morbidity and mortality. Screening of first degree relatives is important owing to the autosomal dominant inheritance pattern of the FH.

Episomal Nonviral Gene Therapy Vectors Slow Progression of Atherosclerosis in a Model of Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is a life-threatening genetic disorder characterized by elevated levels of plasma low-density lipoprotein cholesterol (LDL-cholesterol). Current attempts at gene therapy for FH have been limited by the use of strong heterologous promoters which lack genomic DNA elements essential for regulated expression. Here, we have combined a mini-gene vector expressing the human LDLR cDNA from a 10 kb native human LDLR locus genomic DNA promoter element, with an efficient miRNA targeting 3-hydroxy-3-methylgutaryl-coenzyme A reductase (Hmgcr), to further enhance LDLR expression. We show that the combined vector suppresses endogenous Hmgcr transcripts in vivo, leading to an increase in LDLR transgene expression. In a diet-induced Ldlr^-/- mouse model of FH, we show that administration of the combined vector reduces atherogenic plasma lipids by ~32%. Finally, we demonstrate that our episomal nonviral vectors are able to reduce atherosclerosis by ~40% after 12 weeks in vivo. Taken together, the vector system we describe exploits the normal cellular regulation of the LDLR to provide prolonged expression of LDLR through targeted knockdown of Hmgcr. This novel gene therapy system could act alone, or in synergy with current therapies that modulate intracellular cholesterol, such as statins, greatly enhancing its therapeutic application for FH.

Homozygous familial hypercholesterolaemia in two boys aged 5 and 10 years

Familial hypercholesterolaemia (FH) is an autosomal dominant lipid disorder. Homozygous FH (HFH), though rare, presents in early childhood. Two different presentations of HFH are reported. The first child presented at 5 years of age with xanthomas on the knees, elbows and buttocks and failure to thrive since the second year of life. He was found to be hypertensive with moderate aortic regurgitation. He is now stable on statins and antihypertensives. The second child presented at 10 years of age with multiple xanthomas and severe aortic stenosis. He died of refractory cardiac failure despite emergency aortic balloon valvoplasty due to diffuse coronary artery disease. Strong clinical suspicion can aid early diagnosis and delay cardiovascular complications.

Liver transplantation as a definitive treatment for familial hypercholesterolemia: A series of 36 cases

FH is a genetic disorder characterized by an increase in serum LDL and total cholesterol values. The afflicted patients are at increased risk of premature atherosclerosis and myocardial infarction. Different treatment modalities are present, including pharmacological agents and surgical procedures. The most effective method of therapy in refractive cases is liver transplantation. Herein, we report our experience on 36 cases of patients with FH undergoing liver transplantation in our center, the main referral center of liver transplantation in Iran. The clinical findings, hospital courses, post-operative complications, and patient follow-up are also described.

Long-term efficacy and safety of mipomersen in patients with familial hypercholesterolaemia: 2-year interim results of an open-label extension

AIMS

To evaluate the efficacy and safety of extended dosing with mipomersen in patients with familial hypercholesterolaemia (HC) taking maximally tolerated lipid-lowering therapy.

METHODS AND RESULTS

A planned interim analysis of an ongoing, open-label extension trial in patients (n = 141) with familial HC receiving a subcutaneous injection of 200 mg mipomersen weekly plus maximally tolerated lipid-lowering therapy for up to 104 weeks. The mean changes in low-density lipoprotein cholesterol (LDL-C) from baseline to weeks 26 (n = 130), 52 (n = 111), 76 (n = 66), and 104 (n = 53) were -28, -27, -27, and -28%; and in apolipoprotein B -29, -28, -30, and -31%, respectively. Reductions in total cholesterol, non-high-density lipoprotein-cholesterol, and lipoprotein(a) were comparable with decreases in LDL-C and apolipoprotein B levels. Mean high-density lipoprotein cholesterol increased from baseline by 7 and 6% at weeks 26 and 52, respectively. The long-term safety profile of mipomersen was similar to that reported in the associated randomized placebo-controlled Phase 3 trials. Adverse events included injection site reactions and flu-like symptoms. There was an incremental increase in the median liver fat during the initial 6-12 months that appeared to diminish with continued mipomersen exposure beyond 1 year and returned towards baseline 24 weeks after last drug dose suggestive of adaptation. The median alanine aminotransferase level showed a similar trend over time.

CONCLUSION

Long-term treatment with mipomersen for up to 104 weeks provided sustained reductions in all atherosclerotic lipoproteins measured and a safety profile consistent with prior controlled trials in these high-risk patient populations. CLINICALTRIALS.GOV: NCT00694109.

Lomitapide: a review of its use in adults with homozygous familial hypercholesterolemia

Lomitapide (Juxtapid(TM)), an orally administered inhibitor of the microsomal triglyceride transfer protein, inhibits the synthesis of chylomicrons and very low-density lipoprotein, thereby reducing plasma levels of low-density lipoprotein cholesterol (LDL-C). Lomitapide is used to lower lipid levels in adults with homozygous familial hypercholesterolemia, a rare, potentially life-threatening genetic disease that is commonly caused by mutations in the LDL receptor gene or other genes that affect the function of the LDL receptor. In a multinational single-arm, open-label, 78-week, phase III trial, lomitapide reduced mean plasma LDL-C levels by 50 % from baseline in 23 evaluable adults with homozygous familial hypercholesterolemia over a 26 week treatment period. Reductions from baseline in LDL-C levels were sustained for up to 78 weeks with continued lomitapide treatment. In this study, the initial dosage of lomitapide was 5 mg once daily for two weeks, with upward titration thereafter to 10, 20, 40, and 60 mg at weeks 2, 6, 10, and 14, respectively, or until an individually assessed maximum dosage was achieved. Prior to the start of treatment with lomitapide, other lipid-lowering therapy (including LDL apheresis) was stabilized over a 6-week period, and then continued throughout the lomitapide treatment phase. Lomitapide was generally well tolerated; the most common adverse events in the phase III trial were gastrointestinal events.

Giant Tuberous Xanthomas in a Case of Type IIA Hypercholesterolemia

Tuberous xanthomas are papulonodular skin lesions present in lipoprotein metabolism disorders. A patient presented with multiple large swellings (up to 20 cm in size) all over the body, which on excision were found to be tuberous xanthomas. Investigations revealed the diagnosis of familial hypercholesterolemia. This case is reported to document the unusual presentation of giant tuberous xanthomas.

Homozygous familial hypercholesterolemia: case series and review of the literature

Introduction. Familial hypercholesterolemia (FH) is caused by nonfunctioning low-density lipoprotein (LDL) receptors, resulting in high serum cholesterol. Two types of FH are described: the heterozygous form is diagnosed in adults and responds well to medical therapy; the homozygous form is rare, diagnosed in children, and often requires multiple treatments to prevent complications. Cholesterol accumulation in tissues produces common clinical manifestations including cutaneous xanthomas, coronary artery disease, and aortic stenosis. Treatment options consist of lifestyle modifications, lipid-lowering medications, LDL aphaeresis, and orthotopic liver transplantation (OLT). Case Presentation. Two patients with FH presented at young ages due to characteristic cutaneous xanthomas. The patients underwent cardiac testing that revealed atherosclerotic changes. The patients received maximal medical therapy, but only experienced a small decrease in serum cholesterol and LDL levels. After several years of medical treatment without improvement of symptoms, the patients were listed for OLT. The transplantations were successful, and only one patient had a postoperative complication of acute rejection, treated successfully. Currently, both patients are doing well with regression of the cutaneous xanthomas and atherosclerotic changes. Conclusion. OLT is a safe and effective option for patients with homozygous FH refractory to maximal medical therapy and may represent the optimal treatment for these patients.

Molecular pathology of familial hypercholesterolemia, related dyslipidemias and therapies beyond the statins

The development of the statin class of cholesterol-lowering drugs is one of the most significant success stories of modern pharmacotherapy. World-wide there are an estimated 150 million people on statins, with the emerging economies of India and China predicted to contribute significantly to that number. Notwithstanding their success, a significant number of people cannot tolerate statins because of serious side effects; of equal concern, a substantial proportion of high risk patients fail to reach cholesterol-lowering targets. For these subjects there is an urgent need for new cholesterol-lowering agents to be used alone or in combination with statins. The success of statins has been largely underpinned by knowledge of cholesterol homeostasis at a molecular level, knowledge that was first gleaned in the 1980s from Brown and Goldstein's pioneering studies of familial hypercholesterolemia (FH, OMIM 143890). Follow-up work that has identified a number of intracellular and circulating factors, all capable of disrupting LDL clearance, has revealed that the low-density lipoprotein receptor- (LDLR) mediated clearance pathway is substantially more complex than previously thought. These factors were discovered in studies of individuals with very rare inherited conditions that lead to either hypo- or hypercholesterolemia. These investigations, besides providing clearer insight into the molecular mechanisms regulating plasma LDL concentrations, have also revealed a number of novel therapeutic targets independent from statins. Consequently, a number of novel therapeutic approaches that are based on small interfering bio-molecules, including antisense oligonucleotides, are now in clinical development. These are aimed at impairing the assembly, synthesis and secretion of apolipoprotein B-containing lipoproteins and/or accelerating their hepatic catabolism. The aim of this article is to focus on these recent advances in the understanding of the molecular basis of cholesterol metabolism that should herald novel cholesterol-lowering agents beyond the statins.