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BackgroundHeart disease is the leading cause of premature death for women in Canada. Ischemic heart disease (IHD) is categorized as myocardial infarction (MI) with no obstructive coronary artery disease (MINOCA), ischemia with no obstructive coronary arteries (INOCA), and atherosclerotic obstructive coronary artery disease (CAD) with MI (MI-CAD) or without MI (non-MI CAD). This study aims to study the prevalence of traditional and non-traditional IHD risk factors and their relationships with (M)INOCA compared to MI-CAD and non-MI CAD in young women.MethodsThis study investigated women who presented with premature (≤55 years old) vasomotor entities of (M)INOCA or obstructive CAD confirmed by coronary angiography, who are currently enrolled in either the Leslie Diamond Women’s Heart Health Clinic Registry (WHC) or the Study to Avoid cardioVascular Events in BC (SAVEBC). Univariable and multivariable regression models were applied to investigate associations of risk factors with odds of (M)INOCA, MI-CAD or non-MI CAD.ResultsA total of 254 women enrolled between 2015-2022 were analyzed: 77 INOCA and 37 MINOCA from the WHC and 66 with non-MI CAD and 74 MI-CAD from SAVEBC. Regression analyses demonstrated that migraines and preeclampsia/gestational hypertension were the most significant risk factors with higher likelihood to associate with premature (M)INOCA relative to obstructive CAD. Conversely, the presence of diabetes and a current or previous smoking history had the highest likelihood to associate with premature CAD.ConclusionThere are significant differences in the risk factor profiles of patients with premature (M)INOCA compared to obstructive CAD.

Background: Homozygous familial hypercholesterolemia (HoFH) is a rare genetic disorder characterized by extremely elevated plasma low-density lipoprotein cholesterol and accelerated atherosclerosis. Accurate identification of patients with HoFH is essential as they may be eligible for specialized treatments. We hypothesized that a subset of patients with clinically diagnosed heterozygous FH (HeFH) may in fact have HoFH, and this could be identified by genetic diagnosis. Methods: We recruited patients with a clinical diagnosis of HeFH based on a Dutch Lipid Clinic Network score ≥6 and no secondary cause of hypercholesterolemia. We performed targeted next-generation sequencing of the low-density lipoprotein receptor ( LDLR ), apolipoprotein B ( APOB ), proprotein convertase subtilisin/kexin type 9 ( PCSK9 ), and low-density lipoprotein receptor adapter protein 1 ( LDLRAP1 ) genes, followed by long-read sequencing of the LDLR gene in patients with >1 pathogenic LDLR variant. We examined lipid levels and cardiovascular events. Results: Among 705 patients with clinically diagnosed HeFH, we identified a single pathogenic variant in 300 (42.6%) and >1 pathogenic variant in the LDLR gene in 11 patients (1.6%). We established a genetic diagnosis of HoFH in 6 (0.9%) patients (3 true homozygotes and 3 compound heterozygotes). The mean baseline low-density lipoprotein cholesterol and prevalence of premature cardiovascular disease of patients with genetically identified HoFH was significantly higher than patients with HeFH. Conclusions: In a cohort of patients with clinically diagnosed HeFH, genetic testing including long-read sequencing revealed that 0.9% had HoFH. These patients tended to have a more severe clinical phenotype. Genetic testing of patients with clinical FH may identify patients with HoFH that had eluded clinical diagnosis.

BackgroundProtein truncating mutations in the titin gene are associated with increased risk of atrial fibrillation (AF). However, little is known regarding the underlying pathophysiology.MethodsWe identified a heterozygous titin truncating variant in a patient with unexplained early-onset AF using whole exome sequencing. We used atrial and ventricular patient induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs), CRISPR/Cas9 genetic correction, and engineered heart tissue (EHT) constructs to evaluate the impact of the titin truncating variant on electrophysiology, sarcomere structure, contractility, and gene expression.ResultsWe generated atrial and ventricular iPSC-CMs from the AF patient with the titin truncating variant and a CRISPR/Cas9 genome corrected isogenic control. We demonstrate that the titin truncating variant increases susceptibility to pacing-induced arrhythmia (prevalence of arrhythmogenic phenotypes, 85.7% versus 14.2%;P= 0.03), promotes sarcomere disorganization (mean ± SEM, 66.3 ± 6.8% versus 88.0 ± 2.9%;P= 0.04) in atrial iPSC-CMs, and reduces contractile force (0.013 ± 0.003 mN versus 0.027 ± 0.004 mN;P< 0.01) in atrial EHTs compared to isogenic controls. In ventricular iPSC-CMs, this variant led to altered electrophysiology (90.0% versus 33.3%;P= 0.02) and sarcomere organization (62.0 ± 3.9% versus 82.9 ± 2.9%;P< 0.01) with no change in EHT contractility compared to isogenic controls. RNA-sequencing revealed an upregulation of cell adhesion and extracellular matrix genes in the presence of the titin truncating variant for both atrial and ventricular EHTs.ConclusionsIn a patient with early-onset unexplained AF and normal ventricular function, iPSC-CMs with a titin truncating variant showed structural and electrophysiological abnormalities in both atrial and ventricular preparations, while only atrial EHTs demonstrated reduced contractility. Whole transcriptome sequencing showed upregulation of genes involved in cell-cell and cell-matrix interactions in both atrial and ventricular EHTs. Together, these findings suggest titin truncating variants promote the development of AF through remodeling of atrial cardiac tissue and provide insight into the chamber-specific effects of titin truncating variants.

Doxorubicin is a commonly used chemotherapeutic drug, but its use is limited by doxorubicin-induced cardiotoxicity (DIC), which can lead to irreversible heart failure and death. A missense variant rs2229774 (p.S427L) in the retinoic acid receptor gamma (RARG) gene is associated with increased susceptibility to DIC, but the precise mechanism underlying this association is incompletely understood. We performed molecular dynamic simulations to determine the effect of this variant on RARG structure and then validated these predictions using CRISPR-Cas9-genome-edited, induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). We found that this variant leads to reduced activation of its target genes in response to doxorubicin, including gene pathways involved in DNA repair and consequently an inability to mediate DNA repair after exposure to doxorubicin. Our findings establish a role of RARG p.S427L in attenuating DNA repair in DIC and provide insight into the pathogenesis of this cardiotoxic effect.

Homozygous familial hypercholesterolemia (HoFH) is a rare genetic disease characterized by extreme elevations of low-density lipoprotein cholesterol (LDL-C) and extremely premature atherosclerotic cardiovascular disease. To date, impacts of HoFH and its treatment on the psychosocial wellbeing of patients have been poorly characterized.We performed a systematic review of the association between HoFH and health-related quality of life (HRQL).This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) consensus guidelines. We searched MEDLINE, Embase, The Cochrane Controlled Register of Trials (CENTRAL), Pubmed, Scopus, AfricaWide (via EBSCO), and six trial registries and grey-literature databases from inception to May 2021 for published English-language literature examining HRQL and its determinants in HoFH. Studies were eligible if they included patients with confirmed HoFH and evaluated HRQL using validated tools. We performed a narrative synthesis of qualitative findings from included studies and, where data permitted, random-effects meta-analysis reporting standardized mean differences (SMD) and 95% confidence intervals (CIs).Our review identified seven eligible studies examining HRQL in HoFH participants. Pooling data from two included studies, we found that relative to the general population, HoFH patients demonstrated significantly poorer HRQL in multiple dimensions of the 36-item Short-Form Health Survey (SF-36) with lower scores in physical functioning (SMD -0.37; 95% CI: -0.60, -0.15), role limitations due to physical health (SMD -0.63; 95% CI: -1.24, -0.02), social functioning (SMD -0.61; 95% CI: -1.19, -0.03), bodily pain (SMD -0.24; 95% CI: -0.46, -0.01), and general health (SMD -1.55; 95% CI: -1.80, -1.31). No differences were observed in domains of energy and vitality, mental health and emotional well-being, or role limitations due to emotional problems. Patients suffered high treatment burdens related to lipoprotein apheresis that compromised educational attainment and employment. However, few patients received psychological support in navigating their treatment challenges. No studies evaluated the association of HoFH with incident anxiety, depression, or other psychopathology.Limited data are available on quality of life for patients with HoFH. The available data suggest that these patients may suffer disease-related impairments in quality of life. Future work should aim to elucidate relationships between HoFH and mental health outcomes and develop interventions to improve quality of life in this population.

Familial combined hyperlipidemia (FCHL) is one of the most common inherited lipid phenotypes, characterized by elevated plasma concentrations of apolipoprotein B-100 and triglycerides. The genetic inheritance of FCHL remains poorly understood. The goals of this study were to investigate the polygenetic architecture and cardiovascular risk associated with FCHL.We identified individuals with an FCHL phenotype among 349,222 unrelated participants of European ancestry in the UK Biobank using modified versions of 5 different diagnostic criteria. The prevalence of the FCHL phenotype was 11.44% (n = 39,961), 5.01% (n = 17,485), 1.48% (n = 5,153), 1.10% (n = 3,838), and 0.48% (n = 1,688) according to modified versions of the Consensus Conference, Dutch, Mexico, Brunzell, and Goldstein criteria, respectively. We performed discovery, case-control genome-wide association studies for these different FCHL criteria and identified 175 independent loci associated with FCHL at genome-wide significance. We investigated the association of genetic and clinical risk with FCHL and found that polygenic susceptibility to hypercholesterolemia or hypertriglyceridemia and features of metabolic syndrome were associated with greater prevalence of FCHL. Participants with an FCHL phenotype had a similar risk of incident coronary artery disease compared to participants with monogenic familial hypercholesterolemia (adjusted hazard ratio vs controls [95% confidence interval]: 2.72 [2.31-3.21] and 1.90 [1.30-2.78]).These results suggest that, rather than being a single genetic entity, the FCHL phenotype represents a polygenic susceptibility to dyslipidemia in combination with metabolic abnormalities. The cardiovascular risk associated with an FCHL phenotype is similar to that of monogenic familial hypercholesterolemia, despite being ∼5x more common.

Familial hypercholesterolemia (FH), familial combined hyperlipidemia (FCHL), and elevated lipoprotein (a) (Lp[a]) increase risk of premature coronary artery disease (CAD). The objective of this study was to assess the prevalence of FH, FCHL, elevated Lp(a) and their impact on management in patients with premature CAD.We prospectively recruited men ≤ 50 years and women ≤ 55 with obstructive CAD. FH was defined as Dutch Lipid Clinic Network scores ≥ 6. FCHL was defined as apolipoprotein B1.2 g/L, triglyceride and total cholesterol90th population percentile, and family history of premature cardiovascular disease. Lp(a) ≥ 50 mg/dL was considered to be elevated.Among 263 participants, 9.1% met criteria for FH, 12.5% for FCHL, and 19.4% had elevated Lp(a). Among patients with FH, 37.5% had FH-causing DNA variants. Patients with FH, but not other dyslipidemias, were more likely than nondyslipidemic patients to have received lipid-lowering therapy before presenting with CAD (33.3% vs 12.3%, P = 0.04) and combined lipid-lowering therapy after the presentation (41.7% vs 7.7%, P0.001). One year after presentation, 58.3%, 54.5%, and 58.8% of patients with FH, FCHL, and elevated Lp(a) had low-density lipoprotein cholesterol (LDL-C)1.8 mmol/L, respectively, compared with 68.0 % in reference group. Patients with FCHL were more likely to have non-high-density lipoprotein (HDL) and apolipoprotein B above recommended lipid goals (70.0% and 87.9%, respectively).FH, FCHL, and elevated Lp(a) are common in patients with premature CAD and have differing impact on treatment and achievement of lipid targets. Assessment for these conditions in patients with premature CAD provides valuable information for individualized management.

Aims Patients with familial hypercholesterolaemia (FH) are at increased risk of cardiovascular disease (CVD) due to extremely high circulating LDL cholesterol (LDL-C) concentrations. Our objective was to study the effect of the type of LDL receptor (LDLR) mutation on the incidence of major adverse cardiovascular events (MACEs). Methods and results This was a multinational prospective cohort study, which included patients with heterozygous FH aged 18–65 years, without a prior history of CVD, and carrying a pathogenic or likely pathogenic variant in the LDLR gene. A total of 2131 patients (20 535person-years of follow-up) were included in the study, including 1234 subjects carrying a defective mutation in the LDLR and 897 subjects carrying a null mutation. During the follow-up, a first MACE occurred in 79 cases (6%) in the defective group and in 111 cases (12%) in the null group. The mean baseline LDL-C concentration was 17% higher in the null group than in the defective group (7.90 vs. 6.73 mmoL/L, P < 0.0001). In a Cox regression model corrected for traditional cardiovascular risk factors, the presence of a null mutation was associated with a hazard ratio of 2.09 (1.44–3.05), P = 0.0001. Conclusion Carriers of a null mutation have an independent ∼2-fold increased risk of incident MACE compared with patients carrying a defective mutation. This study highlights the importance of genetic screening in FH in order to improve patient care.

Background: Familial hypercholesterolemia (FH) is a common genetic disorder resulting in high levels of low-density lipoprotein cholesterol and increased risk of atherosclerotic cardiovascular disease. Genetic testing for FH is recommended but is not available in most of Canada. Consequently, there is a paucity of data regarding patient experiences with genetic testing. The objectives of this study were to investigate the attitudes and perspectives of patients with FH who underwent genetic testing. Methods: We administered an anonymous online survey to participants in the British Columbia Familial Hypercholesterolemia Registry who had undergone research-based genetic testing for FH. The survey included 25 questions and explored patients’ experiences with the genetic testing process, willingness to recommend genetic screening, and motivation to lower cholesterol levels. Results: Among 183 respondents, 38 (20.7%) had a positive genetic test result, 27 (14.8%) had a negative result, and 118 (64.4%) were awaiting their results. Compared with individuals awaiting their test results, participants with a positive genetic test were more likely to believe lipid-lowering therapy was highly important (74.3% vs 55.4%; P = 0.05). They were also more likely to strongly agree that a diagnosis of FH was important to them (71.1% vs 46.2%; P = 0.008), and were more likely to recommend genetic screening to their family members (85.9% vs 72.9%; P = 0.04). Conclusions: To our knowledge, this is the first study in Canada to explore the perspectives of patients with FH who underwent genetic testing. These results suggest that genetic testing for FH might offer benefits in important patient-centred outcomes. Résumé: Introduction: L’hypercholestérolémie familiale (HF) est une maladie génétique fréquente qui entraîne des concentrations élevées de cholestérol à lipoprotéines de faible densité et un risque accru de maladies cardiovasculaires athérosclérotiques. L’analyse génétique de l’HF est recommandée, mais n’est pas disponible dans la plupart des régions du Canada. Par conséquent, il existe peu de données sur les expériences des patients ayant subi une analyse génétique. Les objectifs de la présente étude étaient d’enquêter sur les attitudes et les points de vue des patients atteints d’HF qui avaient subi une analyse génétique. Méthodes: Nous avons administré une enquête anonyme en ligne aux participants inscrits dans le registre British Columbia Familial Hypercholesterolemia qui avaient subi une analyse génétique fondée sur la recherche pour l’HF. L’enquête comptait 25 questions et portait sur les expériences des patients sur le processus d’analyse génétique, la volonté de recommander le dépistage génétique et la motivation à abaisser les concentrations de cholestérol. Résultats: Parmi les 183 répondants, 38 (20,7 %) avaient des résultats positifs à l’analyse génétique, 27 (14,8 %) avaient des résultats négatifs et 118 (64,4 %) attendaient leurs résultats. Comparativement aux individus qui attendaient leurs résultats d’analyse, les participants qui avaient des résultats positifs à l’analyse génétique étaient plus susceptibles de penser que le traitement hypolipémiant était très important (74,3 % vs 55,4 %; P = 0,05). Ils étaient aussi plus susceptibles d’être tout à fait d’accord sur le fait que le diagnostic d’HF était important pour eux (71,1 % vs 46,2 %; P = 0,008) et de recommander le dépistage génétique aux membres de leur famille (85,9 % vs 72,9 %; P = 0,04). Conclusions: À notre connaissance, au Canada, c’est la première étude sur les points de vue des patients atteints d’HF qui avaient subi une analyse génétique. Ces résultats indiquent que le dépistage génétique de l’HF pourrait favoriser des résultats importants axés sur le patient.

Purpose of review Contemporary polygenic scores, which summarize the cumulative contribution of millions of common single-nucleotide variants to a phenotypic trait, can have effects comparable to monogenic mutations. This review focuses on the emerging use of 'genome-wide' polygenic scores for plasma lipoproteins to define the etiology of clinical dyslipidemia, modify the severity of monogenic disease, and inform therapeutic options. Recent findings Polygenic scores for low-density lipoprotein cholesterol (LDL-C), triglycerides, and high-density lipoprotein cholesterol are associated with severe hypercholesterolemia, hypertriglyceridemia, or hypoalphalipoproteinemia, respectively. These polygenic scores for LDL-C or triglycerides associate with risk of incident coronary artery disease (CAD) independent of polygenic scores designed specifically for CAD and may identify individuals that benefit most from lipid-lowering medication. Additionally, the severity of hypercholesterolemia and CAD associated with familial hypercholesterolemia-a common monogenic disorder-is modified by these polygenic factors. The current focus of polygenic scores for dyslipidemia is to design predictive polygenic scores for diverse populations and determining how these polygenic scores could be implemented and standardized for use in the clinic. Summary Polygenic scores have shown early promise for the management of dyslipidemias, but several challenges need to be addressed before widespread clinical implementation to ensure that potential benefits are robust and reproducible, equitable, and cost-effective.

Supplemental Digital Content is available in the text., Background: Familial hypercholesterolemia (FH) is a common autosomal codominant genetic disorder, which causes elevated levels of low-density lipoprotein cholesterol (LDL-C) and increased risk of premature atherosclerotic cardiovascular disease (ASCVD). Even among individuals with monogenic FH, there is substantial interindividual variability in LDL-C levels and risk of ASCVD. We assessed the influence of an LDL-C polygenic score on levels of LDL-C and risk of ASCVD for individuals with monogenic FH. Methods: We constructed a weighted LDL-C polygenic score, composed of 28 single-nucleotide variants, for individuals with monogenic FH from the British Columbia FH (n=262); Nutrition, Metabolism and Atherosclerosis Clinic (n=552); and UK Biobank cohorts (n=306). We assessed the association between LDL-C polygenic score with LDL-C levels and ASCVD risk using linear regression and Cox-proportional hazard models, respectively. ASCVD was defined as myocardial infarction, coronary or carotid revascularization, transient ischemic attack, or stroke. The results from individual cohorts were combined in fixed-effect meta-analyses. Results: Levels of LDL-C were significantly associated with LDL-C polygenic score in the Nutrition, Metabolism and Atherosclerosis Clinic cohort, UK Biobank cohort, and in the meta-analysis (β [95% CI]=0.13 [0.072–0.19] per a 20% increase in LDL-C polygenic score percentile, P

Spontaneous coronary artery dissection (SCAD) is a non-atherosclerotic cause of myocardial infarction (MI), typically in young women. We undertook a genome-wide association study of SCAD (Ncases = 270/Ncontrols = 5,263) and identified and replicated an association of rs12740679 at chromosome 1q21.2 (Pdiscovery+replication = 2.19 × 10−12, OR = 1.8) influencing ADAMTSL4 expression. Meta-analysis of discovery and replication samples identified associations with P, Spontaneous coronary artery dissection (SCAD) is a cause of myocardial infarction Here, the authors present a genome-wide association study of SCAD, finding an association at 1q21.2 which potentially affects expression of ADAMTSL4.

Lipoprotein(a) is an atherogenic low-density lipoprotein-like particle and circulating levels are largely determined by genetics. Patients with familial hypercholesterolemia (FH) have elevated lipoprotein(a); however, it remains unclear why.This study compared the levels of lipoprotein(a) and associated genetic factors between individuals that were ascertained for FH clinically versus genetically.We investigated causes of elevated lipoprotein(a) in individuals with clinically diagnosed FH (FH cohort, n = 391) and in individuals with genetically diagnosed FH from the general population (UK Biobank; n = 37,486).Patients in the FH cohort had significantly greater lipoprotein(a) levels than either the general population or non-FH dyslipidemic patients. This was accounted for by increased frequency of the rs10455872-G LPA risk allele (15.1% vs. 8.8%; p 0.05). However, within the FH cohort, lipoprotein(a) levels did not differ based on the presence or absence of an FH-causing variant (means = 1.43 log mg/dl vs. 1.42 log mg/dl; p = 0.97). Lipoprotein(a) levels were also not statistically different between individuals with and without an FH-causing variant in the UK Biobank cohort, which represents a population sample not biased to cardiovascular ascertainment (n = 221 vs. 37,486). We performed a phenome-wide association study between LPA genotypes and 19,202 phenotypes to demonstrate that elevated lipoprotein(a) is associated with increased low-density lipoprotein cholesterol, a family history of cardiovascular disease, premature coronary artery disease, and a diagnosis of FH.These results suggest that FH does not cause elevated lipoprotein(a), but that elevated lipoprotein(a) increases the likelihood that an individual with genetic FH will be clinically recognized.

[Background]: Homozygous familial hypercholesterolaemia (HoFH) is a rare inherited disorder resulting in extremely elevated low-density lipoprotein cholesterol levels and premature atherosclerotic cardiovascular disease (ASCVD). Current guidance about its management and prognosis stems from small studies, mostly from high-income countries. The objective of this study was to assess the clinical and genetic characteristics, as well as the impact, of current practice on health outcomes of HoFH patients globally., [Methods]: The HoFH International Clinical Collaborators registry collected data on patients with a clinical, or genetic, or both, diagnosis of HoFH using a retrospective cohort study design. This trial is registered with ClinicalTrials.gov, NCT04815005., [Findings]: Overall, 751 patients from 38 countries were included, with 565 (75%) reporting biallelic pathogenic variants. The median age of diagnosis was 12∙0 years (IQR 5∙5–27∙0) years. Of the 751 patients, 389 (52%) were female and 362 (48%) were male. Race was reported for 527 patients; 338 (64%) patients were White, 121 (23%) were Asian, and 68 (13%) were Black or mixed race. The major manifestations of ASCVD or aortic stenosis were already present in 65 (9%) of patients at diagnosis of HoFH. Globally, pretreatment LDL cholesterol levels were 14∙7 mmol/L (IQR 11∙6–18∙4). Among patients with detailed therapeutic information, 491 (92%) of 534 received statins, 342 (64%) of 534 received ezetimibe, and 243 (39%) of 621 received lipoprotein apheresis. On-treatment LDL cholesterol levels were lower in high-income countries (3∙93 mmol/L, IQR 2∙6–5∙8) versus non-highincome countries (9∙3 mmol/L, 6∙7–12∙7), with greater use of three or more lipid-lowering therapies (LLT; highincome 66% vs non-high-income 24%) and consequently more patients attaining guideline-recommended LDL cholesterol goals (high-income 21% vs non-high-income 3%). A first major adverse cardiovascular event occurred a decade earlier in non-high-income countries, at a median age of 24∙5 years (IQR 17∙0–34∙5) versus 37∙0 years (29∙0–49∙0) in high-income countries (adjusted hazard ratio 1∙64, 95% CI 1∙13–2∙38)., [Interpretation]: Worldwide, patients with HoFH are diagnosed too late, undertreated, and at high premature ASCVD risk. Greater use of multi-LLT regimens is associated with lower LDL cholesterol levels and better outcomes. Significant global disparities exist in treatment regimens, control of LDL cholesterol levels, and cardiovascular event-free survival, which demands a critical re-evaluation of global health policy to reduce inequalities and improve outcomes for all patients with HoFH., Amsterdam University Medical Centers, Location Academic Medical Center; Perelman School of Medicine at the University of Pennsylvania; and European Atherosclerosis Society

The online version of this article (https://doi.org/10.1016/j. gim.2021.09.012) contains supplementary material, which is available to authorized users. Purpose: In 2015, the American College of Medical Genetics and Genomics (ACMG) and the Association for Molecular Pathology (AMP) published consensus standardized guidelines for sequence-level variant classification in Mendelian disorders. To increase accuracy and consistency, the Clinical Genome Resource Familial Hypercholesterolemia (FH) Variant Curation Expert Panel was tasked with optimizing the existing ACMG/AMP framework for disease-specific classification in FH. In this study, we provide consensus recommendations for the most common FH-associated gene, LDLR, where >2300 unique FH-associated variants have been identified. Methods: The multidisciplinary FH Variant Curation Expert Panel met in person and through frequent emails and conference calls to develop LDLR-specific modifications of ACMG/AMP guidelines. Through iteration, pilot testing, debate, and commentary, consensus among experts was reached. Results: The consensus LDLR variant modifications to existing ACMG/AMP guidelines include (1) alteration of population frequency thresholds, (2) delineation of loss-of-function variant types, (3) functional study criteria specifications, (4) cosegregation criteria specifications, and (5) specific use and thresholds for in silico prediction tools, among others. Conclusion: Establishment of these guidelines as the new standard in the clinical laboratory setting will result in a more evidence-based, harmonized method for LDLR variant classification worldwide, thereby improving the care of patients with FH. Clinical Genome Resource (ClinGen) is primarily funded by the National Human Genome Research Institute through the following 3 grants: U41HG006834, U41HG009649, and U41HG009650. ClinGen also receives support for content curation from the Eunice Kennedy Shriver National Institute of Child Health and Human Development through the following 3 grants: U24HD093483, U24HD093486, and U24HD093487. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. J.R.C. acknowledges her PhD fellowship funded by the Science and Technology Foundation (SFRH/BD/108503/2015). L.T. and T.F. are supported by the Ministry of Health of the Czech Republic (grant NU20-02-00261). S.E.H. is an Emeritus British Heart Foundation Professor and is funded by PG08/ 008 and by the National Institute for Health Research University College London Hospitals Biomedical Research Centre. M.T. is supported by a Vanier Canada Graduate Scholarship. L.R.B. is a Michael Smith Foundation for Health Research scholar and a Canada Research Chair in Precision Cardiovascular Disease Prevention. R.A.H. is supported by the Jacob J. Wolfe Distinguished Medical Research Chair, the Edith Schulich Vinet Canada Research Chair in Human Genetics, the Martha G. Blackburn Chair in Cardiovascular Research, and operating grants from the Canadian Institutes of Health Research (Foundation Grant) and the Heart and Stroke Foundation of Ontario (G-18- 0022147). J.W.K. is supported by the National Institutes of Health through grants P30DK116074 (to the Stanford Diabetes Research Center), R01 DK116750, R01 DK120565, and R01 DK106236 and by the American Diabetes Association (grant #1-19-JDF-108). info:eu-repo/semantics/publishedVersion

Objective: Familial hypercholesterolemia (FH) is associated with a high risk of premature atherosclerotic cardiovascular disease (ASCVD). However, this risk is highly heterogeneous and current risk prediction algorithms for FH suffer from limitations. The primary objective of this study was to develop a score predicting incident ASCVD events over 10 years in a large multinational FH cohort. The secondary objective was to investigate the prediction of major adverse cardiovascular events and cardiovascular mortality using this score. Approach and Results: We prospectively followed 3881 patients with adult heterozygous FH with no prior history of ASCVD (32 361 person-years of follow-up) from 5 registries in Europe and North America. The FH-Risk-Score incorporates 7 clinical variables: sex, age, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, hypertension, smoking, and lipoprotein (a) (Lp(a)) with a Harrell C-index for 10-year ASCVD event of 0.75, which was superior to the SAFEHEART-RE (Spanish Familial Hypercholesterolemia Cohort; 0.69). Subjects with an elevated FH-Risk-Score had decreases in 10-year ASCVD-free survival, 10-year major adverse cardiovascular event-free survival, and 30-year survival for CV mortality compared with the low-risk group, with hazard ratios of 5.52 (3.94–7.73), 4.64 (2.66–8.11), and 10.73 (2.51–45.79), respectively. The FH-Risk-Score showed a similar performance in subjects with and without an FH-causing mutation. Conclusions: The FH-Risk-Score is a stronger predictor of future ASCVD than the SAFEHEART-RE and was developed in FH subjects with no prior cardiovascular event. Furthermore, the FH-Risk-Score is the first score to predict CV death and could offer personalized cardiovascular risk assessment and treatment for patients with FH. Future studies are required to validate the FH-Risk-Score in different ethnic groups.

Background Premature atherosclerotic cardiovascular disease (ASCVD) is highly heritable. The screening of first-degree relatives (FDR) of patients with premature ASCVD is recommended but not routinely performed, and the diagnostic yield of different approaches to such screening is unknown. Purpose To determine the feasibility and diagnostic yield of clinical and radiological screening of FDRs of patients with premature coronary artery disease (CAD) in clinical setting. Method We recruited FDRs of patients with angiographically-proven CAD with stenosis of ≥50% who presented at the age of ≤50 years for males and ≤55 years for females. After clinical and laboratory assessment, patients with no personal history of cardiovascular disease underwent either coronary computed tomography angiography (CCTA), coronary calcium scoring assessment (CAC), or carotid ultrasound (CUS). Subclinical atherosclerosis was defined as 1) CAC score >100 Agatston units or >75% percentile for age and sex; 2) Stenosis >50% in at least one coronary artery or segment involvement scores >50th percentile in males and >75th in females; or, 3) Carotid plaque on ultrasonography. Results We enrolled 220 FDRs between 2017 and 2020, 129 completed clinical assessment (Figure 1). Of them, 28 (21.7%) had a personal history of ASCVD and 101 were tested for subclinical atherosclerosis. The characteristics of these patients are shown in Table 1. The most prevalent cardiovascular risk factors were dyslipidemia (40.6%), hypertension (22.8%), and obesity (21.8%). When assessed with the Framingham risk score calculator without adjustment for family history, only 5.1% and 28.6%, of patients had high or moderate cardiovascular risk, respectively. After adjusting for family history and the presence of statin-indicated conditions, 39.6% and 14.9% of patients were placed in high and moderate risk groups, respectively. Subclinical atherosclerosis was found in 43.6% of all patients (Figure 1) and 57.7% of patients over 40 years of age. The diagnostic yield of procedures was 29.6% for CUS, 37.8% for CCTA and 61.1% for CAC scoring. After the radiological assessment, 13.9% of patients were reclassified to a higher risk group (Table 1). Conclusion Non-invasive cardiovascular imaging detected subclinical atherosclerosis in 43.6% of healthy patients with a family history of premature ASCVD, moving 1 in 7 patients to a higher risk group and suggesting that this screening approach may improve risk prediction in this population. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Canadian Institutes of Health Research.St. Paul's Hospital Foundation and the Vancouver General Hospital Foundation. Figure 1Table 1

Whether low-density lipoprotein (LDL) receptor (LDLR) residual activity influences the LDL-lowering effect of statins in heterozygous familial hypercholesterolemia (HeFH) remains unclear. The objective of this study was to investigate the relationship between the LDLR genotype and statin-induced LDL cholesterol (LDL-C) reductions in HeFH.A total of 615 individuals with HeFH (receptor-defective [RD] genotype: n = 226; receptor-negative [RN] genotype: n = 389) from 7 lipid clinics across Canada who initiated statin monotherapy were included in this retrospective longitudinal study. Statin-induced reductions in LDL-C among individuals with RD and RN genotypes were compared with the use of linear models.There were 334 women and 281 men with a mean untreated LDL-C concentrations of 6.97 ± 1.65 mmol/L. Untreated and on-statin LDL-C levels where higher among patients with an RN genotype: untreated: RN 7.24 (95% confidence interval [CI] 6.98-7.50) mmol/L vs RD 6.70 (95% CI 6.41-6.98) mmol/L (P = 0.0002); on-statin: RN 4.50 (95% CI 4.31-4.70) vs RD 4.05 (95% CI 3.84-4.26) mmol/L (P = 0.0004). After adjustments for age, sex, smoking status, untreated LDL-C concentrations, statin type and dose, as well as the clinic where the patients were treated, the LDL-C-lowering effect of statins was significantly weaker for individuals with an RN mutation than for individuals with an RD mutation: RN: -31.1% (95% CI -34.7% to -27.4) vs RD -36.5% (95% CI -40.4% to -32.6%); P0.0001. The LDLR genotype was the strongest nonmodifiable independent correlate of statin-induced LDL-C reductions (RThe LDLR genotype is significantly associated with statin-induced reductions in LDL-C concentrations in HeFH.

Aims Homozygous familial hypercholesterolaemia (HoFH) is a genetic condition characterized by extremely elevated levels of low-density lipoprotein cholesterol and premature atherosclerotic cardiovascular disease and death. Due to its rarity, accurate assessment of cardiovascular outcomes associated with HoFH and how they have changed over time has been challenging. The goal of this study was to assess the prevalence and age-of-onset of major adverse cardiovascular events (MACE) among patients with HoFH. Methods and results We searched MEDLINE, EMBASE, Pubmed, Cochrane Central Register of Controlled Trials, Scopus, Africa-Wide, Google Scholar, Open Grey, and various clinical trial registries from inception to February 2020 to identify studies reporting on MACE in HoFH patients. We determined the pooled prevalence and mean age-of-onset of MACE outcomes individually using a random effects inverse variance model. We identified 94 studies that met our eligibility criteria. Myocardial infarction and coronary revascularization were common with a prevalence of 15.1% [95% confidence interval (95% CI) 10.7–20.0] and 28.3% (95% CI 22.5–34.3), respectively. The mean age-of-onset was 24.5 (95% CI 19.2–29.8) years for myocardial infarction and 32.2 (95% CI 26.6–37.8) years for revascularization. Sub-group analyses based on the year of publication revealed significant delays in the onset of MACE outcomes post-1990 compared to pre-1990. Egger’s regression suggested possible bias, likely due to small study effects. Conclusions Atherosclerotic cardiovascular disease is common among HoFH patients and occurs at a young age. Age-of-onset of myocardial infarction was delayed by more than a decade from pre-1990 to post-1990, likely attributable to widespread use of statins and other therapies, reflecting substantial progress in the management of this rare but severe disorder.

ImportanceThe emerging genetic basis of spontaneous coronary artery dissection (SCAD) has been defined as both partially complex and monogenic in some patients, involving variants predominantly in genes known to underlie vascular connective tissue diseases (CTDs). The effect of these genetic influences has not been defined in high-risk SCAD phenotypes, and the identification of a high-risk subgroup of individuals may help to guide clinical genetic evaluations of SCAD.ObjectiveTo identify and quantify the burden of rare genetic variation in individuals with SCAD with high-risk clinical features.Design, Setting, and ParticipantsWhole-exome sequencing (WES) was performed for subsequent case-control association analyses and individual variant annotation among individuals with high-risk SCAD. Genetic variants were annotated for pathogenicity by in-silico analysis of genes previously defined by sequencing for vascular CTDs and/or SCAD, as well as genes prioritized by genome-wide association study (GWAS) and colocalization of arterial expression quantitative trait loci. Unbiased genome-wide association analysis of the WES data was performed by comparing aggregated variants in individuals with SCAD to healthy matched controls or the Genome Aggregation Database (gnomAD). This study was conducted at a tertiary care center. Individuals in the Canadian SCAD Registry genetics study with a high-risk SCAD phenotype were selected and defined as peripartum SCAD, recurrent SCAD, or SCAD in an individual with family history of arteriopathy.Main Outcomes and MeasuresBurden of genetic variants defined by DNA sequencing in individuals with high-risk SCAD.ResultsThis study included a total of 336 participants (mean [SD] age, 53.0 [9.5] years; 301 female participants [90%]). Variants in vascular CTD genes were identified in 17.0% of individuals (16 of 94) with high-risk SCAD and were enriched (OR, 2.6; 95% CI, 1.6-4.2; P = 7.8 × 10−4) as compared with gnomAD, with leading significant signals in COL3A1 (OR, 13.4; 95% CI, 4.9-36.2; P = 2.8 × 10−4) and Loeys-Dietz syndrome genes (OR, 7.9; 95% CI, 2.9-21.2; P = 2.0 × 10−3). Variants in GWAS-prioritized genes, observed in 6.4% of individuals (6 of 94) with high-risk SCAD, were also enriched (OR, 3.6; 95% CI, 1.6-8.2; P = 7.4 × 10−3). Variants annotated as likely pathogenic or pathogenic occurred in 4 individuals, in the COL3A1, TGFBR2, and ADAMTSL4 genes. Genome-wide aggregated variant testing identified novel associations with peripartum SCAD.Conclusions and RelevanceIn this genetic study, approximately 1 in 5 individuals with a high-risk SCAD phenotype harbored a rare genetic variant in genes currently implicated for SCAD. Genetic screening in this subgroup of individuals presenting with SCAD may be considered.

Background Familial hypercholesterolemia is a genetic condition characterized by life-long elevations of plasma low-density lipoprotein cholesterol. In addition to life-threatening cardiovascular complications, intratendinous cholesterol deposits (xanthomas) can lead to pain and tendon thickening, particularly in the Achilles. Clinical detection of xanthomas currently relies upon visual assessment and palpation, or ultrasound-based measures of tendon thickening or echotexture. Misdiagnosis of xanthoma can delay the commencement of potentially life-saving lipid-lowering therapy. Our primary purpose was to determine whether analysis of separated fat and water magnetic resonance images may be able to differentiate between xanthomatic and nonxanthomatic Achilles tendons through quantification of intratendinous fat content. The main hypothesis was that Achilles tendon xanthomas will demonstrate greater lipid content than Achilles tendinopathy or healthy control tendons. Methods Bilateral MRI scans of Achilles tendons from 30 participants (n = 10 Achilles tendon xanthoma, n = 10 Achilles overuse tendinopathy, n = 10 healthy controls) were analyzed for total lipid content using the Dixon method of fat and water signal separation. Secondary outcome measures included tendon water content, as well as ultrasound characterization of tendon tissue organization and thickness. Results Fat content was greater in Achilles tendon xanthomas compared to the tendinopathy (p Conclusion MRI-derived measures of Achilles tendon fat content may be able to distinguish xanthomas from control and tendinopathic tissue. Dixon method MRI warrants further evaluation in an adequately powered study to develop and test clinically relevant diagnostic thresholds.

Background A pathogenic variant in LDLR, APOB, or PCSK9 can be identified in 30% to 80% of patients with clinically-diagnosed familial hypercholesterolemia (FH). Alternatively, ∼20% of clinical FH is thought to have a polygenic cause. The cardiovascular disease (CVD) risk associated with polygenic versus monogenic FH is unclear. Objectives This study evaluated the effect of monogenic and polygenic causes of FH on premature (age Methods Targeted sequencing of genes known to cause FH as well as common genetic variants was performed to calculate polygenic scores in patients with “possible,” “probable,” or “definite” FH, according to Dutch Lipid Clinic Network Criteria (n = 626). Patients with a polygenic score ≥80th percentile were considered to have polygenic FH. We examined the risk of unstable angina, myocardial infarction, coronary revascularization, or stoke. Results A monogenic cause of FH was associated with significantly greater risk of CVD (adjusted hazard ratio: 1.96; 95% confidence interval: 1.24 to 3.12; p = 0.004), whereas the risk of CVD in patients with polygenic FH was not significantly different compared with patients in whom no genetic cause of FH was identified. However, the presence of an elevated low-density lipoprotein cholesterol (LDL-C) polygenic risk score further increased CVD risk in patients with monogenic FH (adjusted hazard ratio: 3.06; 95% confidence interval: 1.56 to 5.99; p = 0.001). Conclusions Patients with monogenic FH and superimposed elevated LDL-C polygenic risk scores have the greatest risk of premature CVD. Genetic testing for FH provides important prognostic information that is independent of LDL-C levels.

Purpose of review Sepsis is a common syndrome of multiorgan system dysfunction caused by a dysregulated inflammatory response to an infection and is associated with high rates of mortality. Plasma lipid and lipoprotein levels and composition change profoundly during sepsis and have emerged as both biomarkers and potential therapeutic targets for this condition. The purpose of this article is to review recent progress in the understanding of the molecular regulation of lipid metabolism during sepsis. Recent findings Patients who experience greater declines in high-density lipoprotein during sepsis are at much greater risk of succumbing to organ failure and death. Although the causality of these findings remains unclear, all lipoprotein classes can sequester and prevent the excessive inflammation caused by pathogen-associated lipids during severe infections such as sepsis. This primordial innate immune function has been best characterized for high-density lipoproteins. Most importantly, results from human genetics and preclinical animal studies have suggested that several lipid treatment strategies, initially designed for atherosclerosis, may hold promise as therapies for sepsis. Summary Lipid and lipoprotein metabolism undergoes significant changes during sepsis. An improved understanding of the molecular regulation of these changes may lead to new opportunities for the treatment of sepsis.

Rationale: High-density lipoprotein (HDL) cholesterol (HDL-C) levels decline during sepsis, and lower levels are associated with worse survival. However, the genetic mechanisms underlying changes in HDL-C during sepsis, and whether the relationship with survival is causative, are largely unknown.Objectives: We hypothesized that variation in genes involved in HDL metabolism would contribute to changes in HDL-C levels and clinical outcomes during sepsis.Methods: We performed targeted resequencing of HDL-related genes in 200 patients admitted to an emergency department with sepsis (Early Infection cohort). We examined the association of genetic variants with HDL-C levels, 28-day survival, 90-day survival, organ dysfunction, and need for vasopressor or ventilatory support. Candidate variants were further assessed in the VASST (Vasopressin versus Norepinephrine Infusion in Patients with Septic Shock Trial) cohort (n = 632) and St. Paul's Hospital Intensive Care Unit 2 (SPHICU2) cohort (n = 203).Measurements and Main Results: We identified a rare missense variant in CETP (cholesteryl ester transfer protein gene; rs1800777A) that was associated with significant reductions in HDL-C levels during sepsis. Carriers of the A allele (n = 10) had decreased survival, more organ failure, and greater need for organ support compared with noncarriers. We replicated this finding in the VASST and SPHICU2 cohorts, in which carriers of rs1800777-A (n = 35 and n = 12, respectively) had significantly reduced 28-day survival. Mendelian randomization was consistent with genetically reduced HDL levels being a causal factor for decreased sepsis survival.Conclusions: Our results identify CETP as a critical regulator of HDL levels and clinical outcomes during sepsis. These data point toward a critical role for HDL in sepsis.

Familial hypercholesterolemia (FH) is the most common monogenic disorder causing premature atherosclerotic cardiovascular disease. It affects 1 in 250 individuals worldwide, and of the approximately 145,000 Canadians estimated to have FH, most are undiagnosed. Herein, we provide an update of the 2014 Canadian Cardiovascular Society position statement on FH addressing the need for case identification, prompt recognition, and treatment with statins and ezetimibe, and cascade family screening. We provide a new Canadian definition for FH and tools for clinicians to make a diagnosis. The risk of atherosclerotic cardiovascular disease in patients with "definite" FH is 10- to 20-fold that of a normolipidemic individual and initiating treatment in youth or young adulthood can normalize life expectancy. Target levels for low-density lipoprotein cholesterol are proposed and are aligned with the Canadian Cardiovascular Society guidelines on dyslipidemia. Recommendation for the use of inhibitors of proprotein convertase kexin/subtilisin type 9 are made in patients who cannot achieve therapeutic low-density lipoprotein cholesterol targets on maximally tolerated statins and ezetimibe. The writing committee used the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology in the preparation of the present document, which offers guidance for practical evaluation and management of patients with FH. This position statement also aims to raise awareness of FH nationally, and to mobilize patient support, promote knowledge translation, and availability of treatment and health care resources for this under-recognized, but important medical condition.

Doxorubicin is a chemotherapeutic drug used for the treatment of various malignancies; however, patients can experience cardiotoxic effects and this has limited the use of this potent drug. The mechanisms by which doxorubicin kills cardiomyocytes has been elusive and despite extensive research the exact mechanisms remain unknown. This review focuses on recent advances in our understanding of doxorubicin induced regulated cardiomyocyte death pathways including autophagy, ferroptosis, necroptosis, pyroptosis and apoptosis. Understanding the mechanisms by which doxorubicin leads to cardiomyocyte death may help identify novel therapeutic agents and lead to more targeted approaches to cardiotoxicity testing.

PurposeIn 2015, the American College of Medical Genetics and Genomics (ACMG) and the Association for Molecular Pathology (AMP) published consensus standardized guidelines for variant classification in Mendelian disorders. To increase accuracy and consistency, the Clinical Genome Resource (ClinGen) Familial Hypercholesterolemia (FH) Variant Curation Expert Panel (VCEP) was tasked with optimizing the existing ACMG/AMP framework for disease-specific classification in FH. Here, we provide consensus recommendations for the most common FH-causing gene, LDLR, where >2,300 unique FH-associated variants have been identified.MethodsThe multidisciplinary FH VCEP met in person and through frequent emails and conference calls to develop LDLR-specific modifications of ACMG/AMP guidelines. Through iteration, pilot testing, debate and commentary, consensus among experts was reached.ResultsThe consensus LDLR variant modifications to existing ACMG/AMP guidelines include: 1) alteration of population frequency thresholds; 2) delineation of loss-of-function variant types; 3) functional study criteria specifications; 4) co-segregation criteria specifications; and 5) specific use and thresholds for in silico prediction tools, among others.ConclusionEstablishment of these guidelines as the new standard in the clinical laboratory setting will result in a more evidence-based, harmonized method for LDLR variant classification worldwide, thereby improving the care of FH patients.