Premature Atherosclerotic Cardiovascular Disease Research Articles

Lipoprotein(a): An important piece of the ASCVD risk factor puzzle across diverse populations

Elevated lipoprotein(a) (Lp[a]) is an independent, genetic risk factor for atherosclerotic cardiovascular disease (ASCVD) that impacts ~1.4 billion people globally. Generally, Lp(a) levels remain stable over time; thus, most individuals need only undergo Lp(a) testing through a non-fasting blood draw once in their lifetime, unless elevated Lp(a) is identified. Despite the convenience of the test for clinicians and patients, routine Lp(a) testing has not been widely adopted. This review provides a guide to the benefits of Lp(a) testing and solutions for overcoming common barriers in practice, including access to testing and lack of awareness. Lp(a) testing provides the opportunity to reclassify ASCVD risk and drive intensive cardiovascular risk factor management in individuals with elevated Lp(a), and to identify patients potentially less likely to respond to statins. Moreover, cascade screening can help to identify elevated Lp(a) in relatives of individuals with a personal or family history of premature ASCVD. Overall, given the profound impact of elevated Lp(a) on cardiovascular risk, Lp(a) testing should be an essential component of risk assessment by primary and specialty care providers.

Analysis of routine molecular genetic diagnostics of familial hypercholesterolemia at tertiary care lipid clinics

Abstract Background Familial hypercholesterolemia (FH) is an autosomal dominant genetic disease, causing dyslipidemia and premature atherosclerotic cardiovascular disease (ASCVD), with currently ∼2,000,000 unidentified adult cases as well as ∼500,000 children cases in Europe. Purpose Aim of this study is to analyse the current yield of routine molecular genetic diagnostics for FH and the spectrum of mutations in two specialist lipid clinics. Methods We investigated all genetic tests performed for FH in our clinics over a 4-year period. Reports of causative mutations in the main FH-causing genes including LDLR, APOB, PCSK9 were collected. Variants were classified based on HGVS nomenclature using the mutation database ClinVar. For clinical classification, the Dutch Lipid Clinic Network Score (DLCNS) was used, which is based on off-treatment low-density lipoprotein cholesterol (LDL-C) ranges, family and patient history as well as pathognomonic signs. Results Of 473 patients tested, 102 (21.6%) had a causative mutation (LDLR=84%, APOB=9%, PCSK9=5%), three of which were novel. 14 further, previously unreported variants of unknown significance were identified. The detection rate was 64% in patients with clinically definite FH i.e. DLCNS >8 (10.7% of the cohort), 30% in those with a DLCNS between 6 and 8 (20.6%), 16% in those with a DLCNS between 3 and 5 (47.2%) and 4% in DLCNS <3 (21.5%). The detection rate among those with an off-treatment LDL-C ≥190 mg/dL was 30.5%, and 7.5% in those <190 mg/dL. Median DLCNS at testing was 4, in positively tested 6. Mean off-treatment LDL-C levels were significantly higher in positively compared to negatively tested (266±67 mg/dl vs 198±61 mg/dl; p<0.001), and in those with DLCNS ≥6 compared to <6 (284±67 mg/dl vs 190±53 mg/dl p<0.001). The currently established LDL-C cut-off of 190 mg/dL showed a sensitivity of 90.6% [80.1 - 96.1] and a specificity of 35.9% [29.5 - 42.9], while a DLCNS cut-off of ≥6 shows a sensitivity of 60.3% [48.1 – 71.3], a specificity of 76.7% [71.0 – 81.6]. Both performed well in ROC analyses with an AUC of 0.632 for the LDL-C cut-off of 190 mg/dL vs 0.707 for DLCNS≥6, with an insignificant difference in AUC between the two (-0.075; p=0.053). Conclusions Practically, a simple off-treatment LDL-C cut-off of 190 mg/dL, performing comparably to the more time-consuming DLCNS might enhance the identification of suspected cases especially by non-specialists and in primary care, allowing for a much needed surge in referrals to specialist centers for diagnostic workup, thereby possibly improving diagnosis rates in this severely underdiagnosed disease.Mutation detection within DLCNS groupsOff-treatment LDL-C by mutation status

An investigational in vivo base editing medicine targeting ANGPTL3, VERVE-201, achieves potent and LDLR-independent liver editing in mouse models

Abstract Background VERVE-201 is an investigational medicine composed of a messenger RNA for an adenine base editor and a guide RNA that targets the ANGPTL3 gene packaged in a GalNAc lipid nanoparticle (LNP). Delivered via a one-time intravenous infusion, VERVE-201 is designed to inactivate ANGPTL3 in the liver and thereby lower low-density lipoprotein cholesterol (LDL-C) concentrations to treat atherosclerotic cardiovascular disease (ASCVD). VERVE-201 is initially being developed for the treatment of homozygous familial hypercholesterolemia—a rare genetic disorder in which severe or complete low-density lipoprotein receptor (LDLR)-deficiency leads to marked elevations in LDL-C and premature ASCVD. Purpose We first evaluated the potential of VERVE-201 to achieve on-target ANGPTL3 editing in human liver cells in vitro and humanized ANGPTL3 mice in vivo. Second, while standard LNPs are taken up into hepatocytes primarily by the LDLR, the GalNAc targeting ligand included in the VERVE-201 LNP is expected to enable LDLR-independent delivery via an alternate receptor (ASGPR). We test the hypothesis that VERVE-201mu (mouse surrogate of VERVE-201) can achieve comparable degree of Angptl3 editing in wild-type mice and those with partial (Ldlr+/-) or complete (Ldlr-/-) LDLR-deficiency. Methods VERVE-201 was first assessed in primary human hepatocytes at a range of doses in vitro. To assess whether VERVE-201 edits the human ANGPTL3 gene in vivo, a human ANGPTL3 mouse model was generated and VERVE-201 was evaluated at 7 dose levels ranging from 0.1 to 3.0 mg/kg (n=4 in each group). Next, one of four doses of VERVE-201mu ranging from 0.25 to 2.0 mg/kg or a vehicle control was administered to wild type, Ldlr+/−, and Ldlr−/− mice (n=5 in each genotype treatment group). In mouse experiments, tissue and blood samples were collected 7 days following dosing for evaluation. Results In primary human hepatocytes, VERVE-201 achieved potent and dose-responsive ANGPTL3 editing in cells from each of three donors. In human ANGPTL3 mice, VERVE-201 treatment resulted in dose-responsive liver ANGPTL3 editing. In mice treated with the highest dose of 3 mg/kg, mean liver editing of 64% and reduction in blood ANGPTL3 protein of 98% were observed. In wild type, Ldlr+/−, and Ldlr−/− mice, VERVE-201mu was similarly well-tolerated and achieved highly consistent potency across the doses studied (Figure). In mice treated with the highest dose of 2.0 mg/kg, mean liver Angptl3 editing of 60% and reductions in blood ANGPTL3 protein of 99% were observed, with no detectable differences across wild-type, Ldlr+/−, and Ldlr−/− mice. Conclusions These nonclinical data support the potential of VERVE-201 to enable precise and potent ‘once-and-done’ ANGPTL3 inactivation in the context of the severe or complete LDLR deficiency that occurs in homozygous familial hypercholesterolemia, a patient population that struggles to achieve adequate LDL-C reduction even on multiple lipid-lowering therapies.

Myocardial microvascular dysfunction in asymptomatic patients with hereditary dyslipidemia

Abstract Introduction Microvascular dysfunction underlies the pathophysiology of many cardiovascular disease (CVD) conditions and is strongly associated with future cardiovascular events. Hereditary forms of dyslipidaemia such as familial hypercholesterolemia (FH) and high levels of lipoprotein(a) [Lp(a)] are associated with premature atherosclerotic CVD but the degree of microvascular dysfunction in asymptomatic individuals is not fully explored. Purpose To evaluate the presence of microvascular dysfunction in asymptomatic individuals with the hereditary dyslipidaemias FH and high Lp(a). Methods Asymptomatic individuals without manifest CVD were recruited to four groups with 30 subjects in each; 1) controls with Lp(a)<30 nmol/L, 2) FH+Lp(a)<30 nmol/L, 3) FH+Lp(a)>125 nmol/L, and 4) isolated Lp(a)>125 nmol/L without FH. FH diagnoses were confirmed by genetic analysis. Transthoracic doppler echocardiography was used to record coronary flow in the distal part of the left anterior descending artery at rest and during hyperaemia induced by intravenous infusion of adenosine. Coronary flow reserve (CFR) was calculated by dividing hyperaemic to basal flow. Peripheral microvascular endothelial function was determined by recording reactive hyperaemia index (RHI) by peripheral arterial tonometry in the index fingers of both hands. CFR and RHI were considered impaired if values were <2.5 and <1.67, respectively. Results The four groups were balanced in age (mean 42.6±8.4 years), sex (50% females), BMI (mean 25.0±4.7 kg/m2), and smoking status (5.0% current smokers). Low-density lipoprotein cholesterol was also similar across the four groups (mean 2.8±1.1 mmol/L) with the two FH groups being on cholesterol lowering treatment while the other two were pharmacologically naïve. The three groups with hereditary dyslipidaemia had a higher proportion of subjects with impaired CFR, 30.0% in each group compared to 6.6% in controls (p=0.014) (Figure 1A). The FH+Lp(a)<30 nmol/L and FH+Lp(a)>125 nmol/L groups had received cholesterol lowering treatment for a median (inter quartile range, IQR) of 4.0 (8.0) and 11.0 (11.0) years respectively (p<0.001). In the FH+Lp(a)>125 nmol/L group individuals with normal CFR had received significantly longer treatment (p=0.006) but not in the FH+Lp(a)<30 nmol/L group (p=0.568) (Figure 1B). There were no major differences in median CFR (p=0.550) (Figure 2A) or median RHI (p=0.341) (Figure 2B) levels between the four groups. Conclusion Asymptomatic individuals with the hereditary dyslipidaemias FH and/or high Lp(a) have a higher degree of coronary microvascular dysfunction compared to healthy controls. For individuals with combined traits FH and high Lp(a), the total treatment years of cholesterol lowering is associated with preserved coronary microvascular function suggesting CFR as a potential useful non-invasive tool for cardiovascular risk-stratification in patients with hereditary dyslipidaemias.Figure 1Figure 2

Abstract 14601: Increased Risk of Major Adverse Cardiovascular Events Attributed to Lipoprotein(a) Across Current Atherosclerotic Cardiovascular Disease Risk Categories

Introduction: AHA guidelines recommend measurement of lipoprotein(a) [Lp(a); an inherited, causal risk factor for atherosclerotic cardiovascular disease (ASCVD)] in individuals with a family or personal history of premature ASCVD. Lp(a) measurement is also recommended for recalibrating the 10-year risk score for borderline or intermediate risk individuals. However, there is limited evidence on the risk of MACE attributed to elevated Lp(a) across ASCVD risk categories. Hypothesis: To assess the impact of elevated Lp(a) levels on MACE across ASCVD 10-year risk categories. Methods: This observational, retrospective study included a primary prevention cohort of Caucasian and Black ethnicities from the UK Biobank (2006-2020). Associations of Lp(a) level (categories of 105-150, 150-190, 190-215, and 215-260 nmol/L were compared to Lp(a) <105 nmol/L) with time to first MACE and MI were assessed using Cox proportional hazard models adjusted for age, sex, and ethnicity, stratified by ASCVD 10-year risk score category. Results: The cohort (N=362,061) included 55.2% female, 94.3% Caucasian and 1.6% Black. MACE incidence rates (IR, per 100 person/years) increased with 10-year ASCVD risk score: low risk IR=0.14 (n=161,183), intermediate risk IR=0.72 (n=121,272) and high-risk IR=1.52 (n=27,733). Within and across these risk categories, elevated Lp(a) conferred a significant increase in risk of MACE and myocardial infarction (MI). In the low-risk category, HRs ranged from 1.15-1.55 (MACE) and 1.32-1.72 (MI), in the intermediate risk category HRs ranged from 1.19-1.51 (MACE) and 1.37-1.77 (MI), and in the high-risk category HRs ranged from 1.12-1.55 (MACE) and 1.14-1.76 (MI) (Figure 1). Conclusions: Our study demonstrates that elevated Lp(a) increases the risk of MACE independently of ASCVD risk score. Measuring and considering elevated Lp(a) levels as part of individual ASCVD risk assessment in routine clinical practice may help improve the risk predication.

Sex differences in the perception of cardiovascular risk in familial hypercholesterolemia

Familial hypercholesterolemia (FH), a common genetic condition, is characterized by elevated low-density lipoprotein cholesterol (LDL-C) and premature atherosclerotic cardiovascular disease (ASCVD). Recent data indicate an undertreatment of females with FH. To characterize the role of sex in the perception of FH, its associated ASCVD risk and treatment. A survey investigating for sex differences in the perception of FH was sent to 1073 patients with FH using a cross sectional study design. A total of 412 patients (51.9 % male) responded to the survey; mean age was 56.2 ± 14.4 years. There was a higher proportion of males with ASCVD than females (41.5 % vs. 16.5 %, respectively, p<0.001). Analyses of the survey responses showed that a majority of both males and females agreed that their risk of ASCVD is higher than healthy individuals of same age (70.8 % vs. 74.7 %, respectively, p = 0.434). Females were more concerned about having high LDL-C levels (67.5 % vs. 56.5 % in males, p = 0.024), especially those in secondary prevention programs. As for treatment of FH, approximately 75 % of both sex groups considered statins to be efficient in reducing the risk of myocardial infarction, but less than half of the females considered statins to be safe (44.8 % vs. 60.0 % in males, p = 0.003). No major sex differences were noted regarding the influence of the doctor in their understanding of FH as a disease. Overall, both males and females with FH were well informed about FH, although females were more concerned about having high LDL-C levels and they feared the safety of statins.

OR24-02 Case Series Of Canadian Patients With Homozygous Familial Hypercholesterolemia Treated With ANGPTL3 Inhibitor Evinacumab

Abstract Disclosure: I. Shamsudeen: None. B.W. McCrindle: Consulting Fee; Self; Jansen Pharmaceuticals, Amryt, Ultragenyx, Chiesi, Esperion. R.A. Hegele: Advisory Board Member; Self; Amgen Inc, HLS Pharmaceuticals, Novartis Pharmaceuticals. Consulting Fee; Self; Akcea Therapeutics, Ultragenyx, Medison, Acasti, Amgen Inc, Novartis Pharmaceuticals, Amryt, Amgen Inc, Pfizer, Inc., Arrowhead, Sanofi, HLS Pharmaceuticals, Regeneron Pharmaceuticals. Background: Homozygous familial hypercholesterolemia (HoFH) is an ultrarare, life-threatening condition characterized by markedly elevated levels of low-density lipoprotein cholesterol (LDL-C) due to biallelic LDL receptor variants. Patients have an increased risk of premature atherosclerotic cardiovascular disease (ASCVD). Traditional lipid-lowering agents are minimally effective and the gold standard treatment is serial apheresis. Recently, an angiopoietin-like protein 3 (ANGPTL3) inhibitor, evinacumab, was introduced as a promising new treatment for HoFH. It was FDA-approved in 2021, but is currently available in Canada only through clinical trials or special access programs. Case Presentations: The first five Canadian HoFH patients to receive evinacumab via special access are presented. Their mean age is 24.6 years (SD = 13.9). As of December 2022, they have received evinacumab 15 mg/kg intravenously every four weeks for a mean of 12.2 months (SD = 11.3). Their mean incremental LDL-C reduction is 49.4% (SD = 8.9) on evinacumab along with reduced apheresis frequency for those on serial apheresis. Safety labs for all patients are normal. Brief case summaries are as follows: (a) Patient A is a 36-year-old man with severe ASCVD who has been on evinacumab for 30 months, in addition to a statin, ezetimibe, evolocumab and LDL-apheresis. His time-averaged LDL-C has decreased by 46.2%, from 4.76 to 2.56 mmol/L (184 to 99 mg/dL), on evinacumab. (b) Patient B is a 17-year-old male with elevated LDL-C levels despite being on a statin, ezetimibe and LDL-apheresis. After 14 months on evinacumab, his time-averaged LDL-C reduced by 40.3%, from 8.75 to 5.22 mmol/L (338 to 202 mg/dL). (c) Patient C is a 30-year-old woman with ASCVD and xanthomas on a statin and ezetimibe, but not apheresis. She has been on evinacumab for 12 months with a 57.7% reduction in LDL-C, from 11.43 to 4.83 mmol/L (442 to 187 mg/dL). (d) Patient D is a 36-year-old man with ASCVD on a statin, ezetimibe, evolocumab and lomitapide in addition to plasmapheresis. He started evinacumab 2 months ago and has already had a 42.6% decrease in time-averaged LDL-C, from 4.34 to 2.49 mmol/L (168 to 96 mg/dL). (e) Patient E is a 4-year-old boy with HoFH and xanthomas on a statin, ezetimibe and plasmapheresis. After 3 months of treatment with evinacumab, his time-averaged LDL-C decreased by 59.9%, from 9.45 to 3.79 mmol/L (365 to 147 mg/dL). Concurrently, he has developed unexplained intermittent abdominal pain, with temporary suspension of evinacumab pending further assessment. Discussion: Five HoFH patients with distinctive histories, baseline treatments and ASCVD have all shown marked improvement in LDL-C levels with a mean reduction of 49.4% on evinacumab on top of existing therapy. Overall, observations from our case series suggest that evinacumab is an effective new treatment for HoFH, a life-threatening condition with few therapeutic options. Presentation: Saturday, June 17, 2023

FRI086 Statin Use After Lobar Intracerebral Hemorrhage- Is It Safe?

Abstract Disclosure: D. Vedamurthy: None. M. Ambrosino: None. K. Suri: None. D. Soffer: None. D. Jacoby: None. Background: Observational studies and randomized clinical trials have yielded conflicting data on the role of statins in causing intracerebral hemorrhage. It is unclear whether it is safe to continue statins in patients who have atherosclerotic cardiovascular disease (ASCVD) when they sustain an intracerebral hemorrhage (ICH). It is also not clear whether this risk of ICH (if present) relates to statin use or “too low” levels of LDL-C. Case: 75-year-old female with history of hypertension, hyperlipidemia, and a coronary artery calcium score of 450, presented to the hospital with severe headache and was diagnosed to acute right ICH. She did not smoke, use street drugs or drink excess alcohol. She did not have a family history of premature ASCVD. Her other medication included amlodipine, rosuvastatin and aspirin. Her lipid panel at hospitalization was TC 130 mg/dl, HDL 38 mg/dl, TG 137 mg/dl and LDL-C 70 mg/dl. Imaging studies were negative for cortical venous thrombosis, reversible cerebrovascular constriction, vasculitis, aneurysm, or AV fistula as etiologies. TEE was negative for cardioembolic source. Her hypertension medications were optimized, and she was discharged without any statin therapy. She fortunately recovered with mild deficits. She enrolled in an open-label randomized study- SATURN- which aims to assess safety of statin use in recurrent ICH. Her lipid panel while off statins showed a TC 274 mg/dl, TG 159 mg/dl, markedly elevated LDL-C of 197 mg/dl, and HDL-C 47 mg/dl. She presents to the lipid clinic for risk reduction. Early studies suggested increased ICH related to very low LDL-C levels, especially in the East Asian population. Concerns about statin use and ICH sparked after post-hoc analyses of SPARCL. Data from mendelian randomization studies and meta-analysis have failed to show convincing associations between statin use and ICH. Certain genetic variants, especially related to Apo E, have been shown to enhance this risk for ICH. There is a diversity in management of patients who have sustained an ICH (especially the lobar type as opposed to deep). An open label randomized trial (SATURN) is currently recruiting patients to answer this unresolved question. The dilemma is compounded in patients who have comorbid ASCVD. There are signals that PCSK9 inhibitors may be safer in terms of less propensity to cause intracerebral hemorrhage, but more data is needed. Moreover, the very low LDL-C levels achieved with use of PCSK-9 inhibitors may be concerning. Conclusion: There are no clear major society guidelines to advice clinicians on the best way to manage patients who have sustained a lobar intracerebral hemorrhage and have a compelling reason to be on statins for lipid lowering therapy to treat ASCVD. There are no clear guidelines on how low is “too low” as far as LDL-C targets are concerned. We present this case study as a call for more robust and expedient research in this field. Presentation: Friday, June 16, 2023

Metabolic systems approaches update molecular insights of clinical phenotypes and cardiovascular risk in patients with homozygous familial hypercholesterolemia

BackgroundHomozygous familial hypercholesterolemia (HoFH) is an orphan metabolic disease characterized by extremely elevated low-density lipoprotein cholesterol (LDL-C), xanthomas, aortic stenosis, and premature atherosclerotic cardiovascular disease (ASCVD). In addition to LDL-C, studies in experimental models and small clinical populations have suggested that other types of metabolic molecules might also be risk factors responsible for cardiovascular complications in HoFH, but definitive evidence from large-scale human studies is still lacking. Herein, we aimed to comprehensively characterize the metabolic features and risk factors of human HoFH by using metabolic systems strategies.MethodsTwo independent multi-center cohorts with a total of 868 individuals were included in the cross-sectional study. First, comprehensive serum metabolome/lipidome-wide analyses were employed to identify the metabolomic patterns for differentiating HoFH patients (n = 184) from heterozygous FH (HeFH, n = 376) and non-FH (n = 100) subjects in the discovery cohort. Then, the metabolomic patterns were verified in the validation cohort with 48 HoFH patients, 110 HeFH patients, and 50 non-FH individuals. Subsequently, correlation/regression analyses were performed to investigate the associations of clinical/metabolic alterations with typical phenotypes of HoFH. In the prospective study, a total of 84 HoFH patients with available follow-up were enrolled from the discovery cohort. Targeted metabolomics, deep proteomics, and random forest approaches were performed to investigate the ASCVD-associated biomarkers in HoFH patients.ResultsBeyond LDL-C, various bioactive metabolites in multiple pathways were discovered and validated for differentiating HoFH from HoFH and non-FH. Our results demonstrated that the inflammation and oxidative stress-related metabolites in the pathways of arachidonic acid and lipoprotein(a) metabolism were independently associated with the prevalence of corneal arcus, xanthomas, and supravalvular/valvular aortic stenosis in HoFH patients. Our results also identified a small marker panel consisting of high-density lipoprotein cholesterol, lipoprotein(a), apolipoprotein A1, and eight proinflammatory and proatherogenic metabolites in the pathways of arachidonic acid, phospholipid, carnitine, and sphingolipid metabolism that exhibited significant performances on predicting first ASCVD events in HoFH patients.ConclusionsOur findings demonstrate that human HoFH is associated with a variety of metabolic abnormalities and is more complex than previously known. Furthermore, this study provides additional metabolic alterations that hold promise as residual risk factors in HoFH population.

Effect of causative genetic variants on atherosclerotic cardiovascular disease in heterozygous familial hypercholesterolemia patients.

Heterozygous familial hypercholesterolemia (HFH) is an autosomal dominant genetic disorder leading to a lifetime exposure to high low-density lipoprotein cholesterol (LDL-c) level and an increased risk of premature atherosclerotic cardiovascular disease (ASCVD). We evaluate the effect of a causative genetic variant to predict ASCVD in HFH patients undergoing treatment. A retrospective cohort was conducted on 289 patients with possible, probable, and definite diagnosis of HFH according to Dutch Lipid Clinic Network Score and in whom DNA analyses were performed and mean LDL-c level was above 155 mg/dl. The study population was divided into groups based on the presence or not of a causative variant (pathogenic or likely pathogenic). We observed each of the study's participants for the occurrence of ASCVD. A causative variant was detected in 42.2% of study participants, and ASCVD has occurred in 21.5% of HFH patients. The incidence of ASCVD (27% vs. 17.4%, p = 0.048) and the mean of LDL-c under an optimal medical treatment (226 ± 59 mg/dl vs. 203 ± 37 mg/dl, p = 0.001) were higher in HFH-causative variant carriers than others. After adjusting on confounders, ASCVD was positively associated with LDL-c level [OR = 2.347; 95% (1.305-4.221), p = 0.004] and tends toward a negative association with HDL-c level [OR = 0.140; 95% (0.017-1.166), p = 0.059]. There is no more association between the detection of a causative variant and the occurrence of ASCVD [OR = 1.708; 95% (0.899-3.242), p = 0.102]. Kaplan Meier and log rank test showed no significant differences in event-free survival analysis between study groups (p = 0.523). In this study population under medical care, it seems that the presence of a causative variant did not represent an independent predictor of adverse cardiovascular outcomes in HFH patients, and LDL-c level played an undisputable causal role.

In vitro assessment of the pathogenicity of the LDLR c.2160delC variant in familial hypercholesterolemia

BackgroundFamilial hypercholesterolemia (FH) is an inherited disorder with markedly elevated low-density lipoprotein cholesterol (LDL-C) and premature atherosclerotic cardiovascular disease. Although many mutations have been reported in FH, only a few have been identified as pathogenic mutations. This study aimed to confirm the pathogenicity of the LDL receptor (LDLR) c.2160delC variant in FH.MethodsIn this study, the proband and her family members were systematically investigated, and a pedigree map was drawn. High-throughput whole-exome sequencing was used to explore the variants in this family. Next, quantitative polymerase chain reaction (qPCR), western blot (WB) assays, and flow cytometry were conducted to detect the effect of the LDLR c.2160delC variant on its expression. The LDL uptake capacity and cell localization of LDLR variants were analyzed by confocal microscopy.ResultsAccording to Dutch Lipid Clinic Network (DLCN) diagnostic criteria, three FH patients were identified with the LDLR c.2160delC variant in this family. An in-silico analysis suggested that the deletion mutation at the 2160 site of LDLR causes a termination mutation. The results of qPCR and WB verified that the LDLR c.2160delC variant led to early termination of LDLR gene transcription. Furthermore, the LDLR c.2160delC variant caused LDLR to accumulate in the endoplasmic reticulum, preventing it from reaching the cell surface and internalizing LDL.ConclusionsThe LDLR c.2160delC variant is a terminating mutation that plays a pathogenic role in FH.

Risk of atherosclerotic cardiovascular disease in patients with premature ASCVD: A study from approximately 1 million young adults

Abstract Funding Acknowledgements Type of funding sources: None. Background Risk of atherosclerotic cardiovascular disease (ASCVD) attributable to premature ASCVD remains poorly understood. Purpose To evaluate the risk of ASCVD among those with premature ASCVD versus those without in a large contemporary population. Methods This observational cohort study included young adults (ages 30-55 years) with and without prior ASCVD (as of January 1, 2006) who were members of an integrated healthcare delivery system in Northern California. Adjusted multivariate models were specified to estimate risk ratios (RRs) for incident ASCVD events by ASCVD status at baseline. Incident ASCVD events were defined as a composite of nonfatal myocardial infarction, ischemic stroke, or coronary heart disease death through December 31, 2020. Results A total of 929,214 individuals met the selection criteria of no prior ASCVD and 5,703 with prior ASCVD. Mean age was 43.9 (±7.3) years and 50.0 (±5.2) years, respectively. Fifty-two and thirty percent were women in each cohort, and the median follow-up was 11.8 and 8.3 years, respectively. Crude ASCVD rate was 2.1 and 24.5 events per 1,000 person-years, respectively. Age-adjusted Kaplan-Meier curves for ASCVD in individuals with and without prior ASCVD in Figure. In models adjusted for demographics (sex, age, race) and traditional risk factors (diabetes, hypertension, LDL-cholesterol, HDL-cholesterol, total cholesterol, smoking), individuals with prior ASCVD had RR of 4.6 (95% CI 4.3-5.0) for CHD, RR of 3.0 (95% CI 2.7-3.4) for stroke and RR of 4.1 (95% CI 3.8-4.3) for ASCVD. Conclusions Risk of ASCVD among those with prior ASCVD was several-fold greater compared to those without prior ASCVD. Continued efforts for secondary prevention are needed in this vulnerable high-risk population.

Identification of pathogenic variants in the Brazilian cohort with Familial hypercholesterolemia using exon-targeted gene sequencing

Familial hypercholesterolemia (FH) is a monogenic disease characterized by high plasma low-density lipoprotein cholesterol (LDL-c) levels and increased risk of premature atherosclerotic cardiovascular disease. Mutations in FH‐related genes account for 40% of FH cases worldwide. In this study, we aimed to assess the pathogenic variants in FH-related genes in the Brazilian FH cohort FHBGEP using exon-targeted gene sequencing (ETGS) strategy. FH patients (n = 210) were enrolled at five clinical sites and peripheral blood samples were obtained for laboratory testing and genomic DNA extraction. ETGS was performed using MiSeq platform (Illumina). To identify deleterious variants in LDLR, APOB, PCSK9, and LDLRAP1, the long-reads were subjected to Burrows-Wheeler Aligner (BWA) for alignment and mapping, followed by variant calling using Genome Analysis Toolkit (GATK) and ANNOVAR for variant annotation. The variants were further filtered using in-house custom scripts and classified according to the American College Medical Genetics and Genomics (ACMG) guidelines. A total of 174 variants were identified including 85 missense, 3 stop-gain, 9 splice-site, 6 InDel, and 71 in regulatory regions (3′UTR and 5′UTR). Fifty-two patients (24.7%) had 30 known pathogenic or likely pathogenic variants in FH-related genes according to the American College Medical and Genetics and Genomics guidelines. Fifty-three known variants were classified as benign, or likely benign and 87 known variants have shown uncertain significance. Four novel variants were discovered and classified as such due to their absence in existing databases. In conclusion, ETGS and in silico prediction studies are useful tools for screening deleterious variants and identification of novel variants in FH-related genes, they also contribute to the molecular diagnosis in the FHBGEP cohort.

Clinical characteristics of adult and paediatric patients with familial hypercholesterolemia: A real-life cross-sectional study from the Turkish National Database

Background and aimsFamilial hypercholesterolemia (FH) is the most common cause of premature atherosclerotic cardiovascular disease (ASCVD). Türkiye is among the countries with the highest rate of ASCVD. However, no population-based study has been published so far on the prevalence of FH, demographic and clinical characteristics, burden of ASCVD, treatment compliance, and attainment of low-density lipoprotein cholesterol (LDL-C) targets. MethodsWe performed a study using the Turkish Ministry of Health's national electronic health records involving 83,063,515 citizens as of December 2021 dating back 2016. Adults fulfilling the diagnostic criteria of definite or probable FH according to the Dutch Lipid Network Criteria (DLNC), and children and adolescents fulfilling the criteria of probable FH according to the European Atherosclerosis Society (EAS) Consensus Panel report formed the study population (n = 157,790). The primary endpoint was the prevalence of FH. ResultsProbable or definite FH was detected in 0.63% (1 in 158) of the adults and 0.61% (1 in 164) of the total population. The proportion of adults with LDL-C levels >4.9 mmol/L (190 mg/dL) was 4.56% (1 in 22). The prevalence of FH among children and adolescents was 0.37% (1 in 270). Less than one-third of the children and adolescents, and two-thirds of young adults (aged 18–29) with FH were already diagnosed with dyslipidaemia. The proportion of adults and children and adolescents on lipid-lowering treatment (LLT) was 32.1% and 1.5%, respectively. The overall discontinuation rate of LLT was 65.8% among adults and 77.9% among children and adolescents. Almost no subjects on LLT were found to attain the target LDL-C levels. ConclusionsThis nationwide study showed a very high prevalence of FH in Türkiye. Patients with FH are diagnosed late and treated sub-optimally. Whether these findings may explain the high rates of premature ASCVD in Türkiye needs further investigation. These results denote the urgent need for country-wide initiatives for early diagnosis and effective management of FH patients.

Different clinical phenotypes of a pair of siblings with familial hypercholesterolemia: a case report and literature review

BackgroundFamilial hypercholesterolemia (FH) leads to high plasma low-density lipoprotein cholesterol (LDL-C) levels and early cardiovascular morbidity and mortality. We treated a pair of siblings with FH. The cardiovascular manifestations in the proband were more severe than those in his elder sister, although they had almost similar LDL-C levels, ages, and lifestyles. Herein, we report the cases of this family to explore the possible causes of clinical phenotypic differences within the same genetic background.Case presentationWe treated a 27-year-old male patient and his 30-year-old sister, both with FH. The coronary angiogram in the male patient revealed 80, 70, and 100% stenosis of the initial, distal right coronary artery branch, and left anterior descending branch, respectively, whereas his sister had almost no coronary stenosis. We treated them accordingly and performed family screening. We found that the LDL-C/particle discordance of the proband is much greater than that of his elder sister. In addition, the average size of LDL-C particle in the proband was smaller than that in his sister.ConclusionsPatients with FH have a much higher risk of premature atherosclerotic cardiovascular disease, but the clinical manifestations are heterogeneous. The smaller LDL particle size may be the underlying cause for different clinical outcomes in this pair of FH cases and be a potential novel indicator for predicting the prognosis of FH.

Successful treatment with lomitapide in a patient with homozygous familial hypercholesterolemia and severe fatty liver disease

Introduction and Aims: Homozygous-familial hypercholesterolemia (Ho-FH) is a rare condition due to biallelic mutations in low-density lipoprotein-receptor (LDL-R) genes characterized by high level of LDL-cholesterol (LDL-c) and huge risk of premature atherosclerotic cardiovascular disease (ASCVD), determining low quality of life and life expectancy. Lomitapide represents a therapeutic option for Ho-FH, but caution should be observed when used in fatty liver disease (FLD) and hypertransaminasemia since it is associated with onset/worsening of liver steatosis. We present a case of safe lomitapide therapy in an adult Ho-FH patient with pre-existing FLD. Case presentation: A 39-year-old man with severe hypercholesterolemia since childhood (LDL-c 405 mg/dl) and premature coronary heart disease history, was referred to our Modena Lipid Clinic. He presented an overt metabolic syndrome, FLD with hypertransaminasemia and elastosonographic significant liver fibrosis. Lipid-lowering-therapy (LLT) included rosuvastatin 20 mg, ezetimibe and evolocumab 140 mg twice a month without reaching LDL-c goal. Genetic analysis revealed homozygous pathogenic LDL-R gene mutation. Evolocumab was increased up to 420 mg twice a month and LDL-apheresis was started with quality of life worsening. Therefore, lomitapide 5 mg daily and low-fat diet were started, obtaining weight loss and lipid profile improvement. However, liver enzymes elevation higher than 5-fold was observed, leading to lomitapide discontinuation and baseline liver enzymes values restoration. After one-month wash-out, lomitapide was gradually reintroduced up to 5 mg daily without significant hypertransaminasemia recurrence, leading to LDL-c target achievement and LDL-apheresis discontinuation. Adherence to low-fat diet and weight loss resulted in FLD and fibrosis improvement. Conclusion: Ho-FH requires complex, combined treatment. Metabolic comorbidities co-existence makes Ho-FH management more difficult. Lomitapide can be safely used in Ho-FH patients with FLD and hypertransaminasemia, but strict follow-up of liver disease and a multidisciplinary approach are needed. Before lomitapide introduction, low-fat diet should be started advantageously and weight stabilization should be obtained.

Additive Effect of APOE Rare Variants on the Phenotype of Familial Hypercholesterolemia.

Autosomal dominant hypercholesterolemia (ADH) is due to deleterious variants in LDLR, APOB, or PCSK9 genes. Double heterozygote for these genes induces a more severe phenotype. More recently, a new causative variant of heterozygous ADH was identified in APOE. Here we study the phenotype of 21 adult patients, double heterozygotes for rare LDLR and rare APOE variants (LDLR+APOE) in a national wide French cohort. LDLR, APOB, PCSK9, and APOE genes were sequenced in 5743 probands addressed for ADH genotyping. The lipid profile and occurrence of premature atherosclerotic cardiovascular diseases were compared between the LDLR+APOE carriers (n=21) and the carriers of the same LDLR causative variants alone (n=22). The prevalence of LDLR+APOE carriers in this French ADH cohort is 0.4%. Overall, LDL (low-density lipoprotein)-cholesterol concentrations were 23% higher in LDLR+APOE patients than in LDLR patients (9.14±2.51 versus 7.43±1.59 mmol/L, P=0.0221). When only deleterious or probably deleterious variants were considered, the LDL-cholesterol concentrations were 46% higher in LDLR+APOE carriers than in LDLR carriers (10.83±3.45 versus 7.43±1.59 mmol/L, P=0.0270). Two patients exhibited a homozygous familial hypercholesterolemia phenotype (LDL-cholesterol >13 mmol/L). Premature atherosclerotic cardiovascular disease was more common in LDLR+APOE patients than in LDLR carriers (70% versus 30%, P=0.026). Although an incomplete penetrance should be taken into account for APOE variant classification, these results suggest an additive effect of deleterious APOE variants on ADH phenotype highlighting the relevance of APOE sequencing.

Parental Attitudes and Ideas Regarding Newborn Screening for Familial Hypercholesterolemia.

Familial hypercholesterolemia (FH) is an inherited disease which causes premature atherosclerotic cardiovascular disease. However, less than 10% of individuals with FH have been identified. To assess parental perspectives for inclusion of FH on routine newborn screening (NBS) and to highlight potential benefits, harms, and ethical concerns. Telephone interviews of two groups were conducted: 1) parents of children diagnosed with FH, and 2) parents of children diagnosed with a genetic condition through NBS. Stratified purposive sampling was used to ensure adequate representation. The 11 telephone interviews were conducted in 30-min sessions guided by a semi-structured interview script. At the beginning of the interview, participants were educated on the NBS process and FH. The interviews were transcribed verbatim, and a thematic analysis was performed in multiple steps. All interviewees indicated that they would be interested in having their child be screened for FH on the newborn screen. Reasons supporting screening during the newborn period included knowing their child's diagnosis, the ability to screen family members for FH, incorporation of lifestyle changes, and access to preventive care. Negatives surrounding screening during the newborn period included increased stress or anxiety, knowledge, stigma, and the delay from diagnosis to initiation of pharmacotherapy for FH. While these interviewees were in favor of NBS for FH, further education of parents and clinicians is needed to ensure proper implementation. The results of this study may be useful to formulate family notification and care protocols for newborns diagnosed with FH and other diseases.

Metabolic syndrome predicts cardiovascular risk and mortality in familial hypercholesterolemia

The association between familial hypercholesterolemia (FH) and premature atherosclerotic cardiovascular disease (ASCVD) is well established. Several risk factors other than the cumulative low-density lipoprotein cholesterol (LDL-C) have been shown to modulate the severity of the phenotype in these patients. However, the effect of the metabolic syndrome (MetS) on ASCVD risk in FH remains to be determined. The objective was to study the association between the presence of MetS and the incidence of different ASCVD endpoints and all-cause mortality. This prospective follow up study used data from 5 independent FH cohorts from Europe and North America. We analysed data of 2401 adult heterozygous FH without history of a prior ASCVD event (21,139 person-years of follow-up). Multivariate Cox proportional hazards regression was used to estimate the association between MetS and the incidence of the different endpoints. The prevalence of MetS was 14% in the study population. The presence of MetS was a significant predictor of incident 10-year ASCVD after adjustment for traditional cardiovascular risk factors (HR 2.07, 95% CI 1.34-3.19), as well as of 10-year major adverse cardiovascular event (MACE) (HR 4.59, 95% CI 2.27-9.30), 10-year myocardial infarction (MI) (HR 4.29, 95% CI 1.91-9.63), and 30-year all-cause mortality (HR 4.87, 95% CI 1.99-11.89). Our findings suggests that FH patients with MetS, have an increased cardiovascular risk that is independent from LDL-C and other traditional risk factors. Future studies are required to determine the most appropriate strategy to reduce the cardiovascular burden associated with MetS in this population.

A Systematic Review on the Risk Modulators of Myocardial Infarction in the “Young”—Implications of Lipoprotein (a)

The presence of a myocardial infarction at a younger age is of special interest, considering the psychological and socioeconomic impact, as well as long-term morbidity and mortality. However, this group has a unique risk profile, with less traditional cardiovascular risk factors that are not well studied. This systematic review aims to evaluate traditional risk factors of myocardial infarction in the "young", highlighting the clinical implications of lipoprotein (a). We performed a comprehensive search using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) standards; we systematically searched the PubMed, EMBASE, and Science Direct Scopus databases, using the terms: "myocardial infarction", "young", "lipoprotein (a)", "low-density lipoprotein", "risk factors". The search identified 334 articles which were screened, and, at the end, 9 original research articles regarding the implications of lipoprotein (a) in myocardial infarction in the "young" were included in the qualitative synthesis. Elevated lipoprotein (a) levels were independently associated with an increased risk of coronary artery disease, especially in young patients, where this risk increased by threefold. Thus, it is recommended to measure the lipoprotein (a) levels in individuals with suspected familial hypercholesterolaemia or with premature atherosclerotic cardiovascular disease and no other identifiable risk factors, in order to identify patients who might benefit from a more intensive therapeutic approach and follow-up.