Evolocumab treatment reduces carotid intima-media thickness in paediatric patients with heterozygous familial hypercholesterolaemia

Background

Familial hypercholesterolemia (FH) is characterised by high plasma levels of low-density lipoprotein cholesterol (LDL-C) and increased risk of premature atherosclerotic cardiovascular disease (ASCVD). Previous studies show that carotid intima-media thickness (cIMT) is increased in children with FH, an indicator of early ASCVD. Add-on treatment with the proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor, evolocumab, substantially reduced atherosclerotic lipid levels in children with heterozygous FH (HeFH) and was safe and well tolerated. The effect of evolocumab on cIMT in paediatric patients (pts) has not been investigated.

Purpose

To investigate the effect of evolocumab treatment on cIMT progression in paediatric pts with HeFH.

Methods

HAUSER-RCT was a multicenter, randomised, placebo-controlled study in which paediatric FH pts (ages 10–17 years) received monthly subcutaneous injections of evolocumab 420 mg or placebo. Of 157 pts, 150 continued to an open-label extension study (HAUSER-OLE) during which all received up to 80 weeks of monthly evolocumab 420 mg on top of stable background statin therapy. cIMT was measured by B-mode ultrasound scanning at baseline, week 24 of the RCT, and weeks 24, 48, and 80 of the OLE. cIMT was measured on anterior, lateral, and posterior imaging angles of the right and left common carotid artery. Mean thickness at each visit and mean changes from baseline were summarised by treatment received during the RCT and artery location. In addition, the largest measurements (anterior, lateral, or posterior) from a patient's left and right carotid artery were averaged to calculate a summary score.

Results

Mean baseline cIMT summary score was 0.568 mm (SD=0.06) for 46 placebo pts and 0.586 mm (SD=0.06) for 82 evolocumab pts. During the RCT, 37 placebo pts had a mean increase of 0.006 mm (SD=0.05) from baseline to week 24; in contrast, 76 evolocumab pts had a mean decrease of 0.003 mm (SD=0.05). Although this treatment group difference was not statistically significant (P=0.403), the pattern of increased cIMT for placebo and decreased cIMT for evolocumab was consistent across artery locations (Table). During the OLE, for pts who initially received placebo, mean cIMT summary score decreased by 0.019 mm (SD=0.04, n=34) from baseline to week 80 (P=0.007) (Figure). Pts who received evolocumab in both the RCT and OLE showed continued improvement during the OLE; at week 80, mean cIMT summary score decreased by 0.012 mm (SD=0.05, n=59) from baseline (P=0.067). For all pts at week 80 (n=128), the mean decrease in LDL-C from baseline was 35.3% (SD=28.0).

Conclusions

Open-label evolocumab treatment for up to 80 weeks led to reductions in mean cIMT. In this small sample of pts with FH, the data suggest that the addition of PCSK9 inhibition to background lipid-lowering therapy has the potential to reduce the risk of ASCVD progression and future cardiovascular events in this vulnerable paediatric population.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Amgen, Inc.

Comparison over 25 years of the burden of familial hypercholesterolemia on hospitalizations for coronary heart disease in a French-Canadian founder population

Background

Over the last 25 years, effective treatments, such as potent statins, ezetimibe and PCSK9 inhibitors have gradually emerged to treat heterozygous familial hypercholesterolemia (FH) and guidelines have been progressively developed internationally to promote FH health surveillance, early diagnosis and optimal clinical management. However, the impact of these measures on the burden of FH is not well documented. Although recent genetic and epidemiological studies suggest that the prevalence of familial hypercholesterolaemia (FH) is approximately twice than initialy expected (1:250) (1), it remains significantly higher among French Canadians (FC) (2,3).

Purpose

To compare over 25 years the management and burden of FH among patients hospitalized for an acute coronary heart disease (CHD) event in a FC founder population with a high prevalence of FH.

Methods

Lipid profiles, cardiovascular risk factors, lipid management and FH status of 2,029 FC patients consecutively hospitalized for an acute CHD event between 2017 and 2022 (2022 Cohort) were compared to those of 2,506 patients with angiographically-confirmed CHD who were admitted between 1995 and 1998 (1998 Cohort) (4). FH status was based on molecular, Simon Broome or FH Canada (5) criteria. Statistical comparisons were made using Chi-square and Student's t-tests for independent samples.

Results

Over a 25-year interval, most patients hospitalized for CHD were men (74.5% in 1998 vs 73.4% in 2022). At the time of admission, 23.0% of CHD patients had LDL-Cholesterol levels >5.0 mmol/L in 1998 compared to 1.3% in 2022 (p<0.001). FH was diagnosed in 9.6% of patients in the 1998 cohort compared to 5.5% in 2022 (p<0.001). Overall, the prevalence of obesity, type 2 diabetes and uncontrolled hypertension tended to be higher in 1998, including in FH (p<0.05). The proportion of FH patients hospitalized for CHD who were treated with a statin or a combination of lipid-lowering agents at the moment of admission was 28.4% in 1998 compared to 61.2% in 2022 (p<0.001). FH patients hospitalized for CHD were significantly older in 2022 than in 1998 (59.03±11.17 vs 50.14±11.32 years; p<0.001). Accordingly, the prevalence of premature CHD requiring an hospitalization significantly decreased from 1998 to 2022 in FH (64.3% vs. 44.1%, p<0.001).

Conclusions

Over a 25-year period, FH patients hospitalized for CHD tend to be older and contribute to a lower proportion of hospitalizations. Despite significant improvement in treatment, FH diagnosis and management remain sub-optimal, even in a founder population where FH represents a significant population burden.

Funding Acknowledgement

Type of funding sources: None.

4944The contribution of familial hypercholesterolemia (FH) to premature coronary artery disease decreased by 2-fold between 1998 and 2018 in a founder population with high prevalence of FH

Background

Familial hypercholesterolemia (FH) is an autosomal dominant trait associated with high risk of premature coronary artery disease (CAD). The worldwide prevalence of FH is estimated at 1:250 to 1:500. In certain populations, including French Canadians (FC), the prevalence is significantly higher however. From 1995 to 1998, FH contributed to 9.6% of angiographically proven CAD in a FC founder population, the burden being the highest in men aged <50 years (20.6%). In the past 2 decades, powerful statins, ezetimibe and other low-density lipoprotein-Cholesterol (LDL-C) modulators, such as PCSK9 inhibitors, have been progressively introduced and several FH diagnosis scoring systems or guidelines have been developed and disseminated in order to facilitate FH recognition and management. The impact of these measures on the FH burden is however not documented.

Purpose

To compare the burden of FH twenty years apart in FC patients hospitalized for CAD.

Methods

Lipid profiles, cardiovascular risk factors and FH status of 1,132 FC patients who were hospitalized for a CAD event and who consecutively attended the cardiovascular disease clinic in 2017 and 2018 were compared to those of 2,506 who consecutively presented angiographically proven CAD two decades ago. FH status was based on Simon Broome and FH Canada definitions. In 1998, all consenting CAD patients were also molecularly screened for the most prevalent FH causing mutations in FC. Comparisons between groups were performed using Chi-square and independent samples Student's t-test.

Results

Most patients in both cohorts were males (74.5% vs 73.9% in 1998 vs. 2018, respectively). At admission, mean LDL-C (± SD) was 3.99±1.67 in 1998 vs. 2.22±1.06 in 2018 (p<0.001). The proportion of patients who were treated with a statin or another lipid lowering agent was 32.9% in 1998 compared to 67.6% in 2018 (p<0.001) and the drug regimen was also significantly different. In 1998, 24.6% of patients had LDL-C >5.0 mmol/L at admission compared to 4.2% in 2018. Definite FH was diagnosed in 9.6% of patients in the 1998 cohort compared to 4.7% in the 2018 cohort (p<0.001). FH patients hospitalized for CAD were significantly older in 2018 than in 1998 (56.3±11.3 vs. 49.2±10.9 in men, p=0.001; 61.1±11.8 vs. 53.2±12.3 in women, p=0.02). In the same period, the relative burden of diabetes and other lipid disorders, including high-density lipoprotein dysmetabolism significantly increased (p<0.001).

Conclusions

Over a period of 20 years, in a founder population with a high prevalence of FH, the contribution of FH to hospitalizations for CAD decreased by 2-fold and affected patients now tend to be hospitalized at an older age than 2 decades ago. This suggests that early diagnosis and more effective management of FH in the last 2 decades have contributed to significantly decrease its burden.

Acknowledgement/Funding

ECOGENE-21, Amgen, Sanofi

Visceral fat enhances blood pressure reactivity to physical but not mental challenges in male adolescents

BACKGROUND

Excess visceral fat is a major risk factor for hypertension. Enhanced blood pressure (BP) reactivity and delayed BP recovery from physical and mental challenges predict future hypertension.

OBJECTIVES

Determine whether visceral fat is associated with higher BP reactivity and delayed BP recovery from physical and mental challenges during adolescence.

METHODS

In a community-based sample of 283 male and 308 female adolescents, we measured visceral fat with magnetic resonance imaging, total body fat with bioimpedance, and beat-by-beat BP with a Finometer at rest and during physical (10-min standing) and mental (2-min math stress) challenges.

RESULTS

Males vs. females showed greater BP reactivity and no differences in BP recovery from either type of challenges. Visceral fat was positively associated with BP reactivity to standing up only and in males only (+8.4 ± 3.6 mmHg per 1 log cm(3) of visceral fat, P = 0.008), and this association was independent of total body fat. No association was seen between visceral fat and BP recovery from either type of challenge in either sex. All these associations were independent of age, puberty stage, height and initial BP.

CONCLUSIONS

Adolescent males vs. females demonstrate greater BP reactivity but similar BP recovery from physical and mental challenges. Excess visceral fat enhances BP reactivity to physical but not mental challenges in males only.

Saguenay Youth Study: a multi-generational approach to studying virtual trajectories of the brain and cardio-metabolic health

This paper provides an overview of the Saguenay Youth Study (SYS) and its parental arm. The overarching goal of this effort is to develop trans-generational models of developmental cascades contributing to the emergence of common chronic disorders, such as depression, addictions, dementia and cardio-metabolic diseases. Over the past 10 years, we have acquired detailed brain and cardio-metabolic phenotypes, and genome-wide genotypes, in 1029 adolescents recruited in a population with a known genetic founder effect. At present, we are extending this dataset to acquire comparable phenotypes and genotypes in the biological parents of these individuals. After providing conceptual background for this work (transactions across time, systems and organs), we describe briefly the tools employed in the adolescent arm of this cohort and highlight some of the initial accomplishments. We then outline in detail the phenotyping protocol used to acquire comparable data in the parents.

DNA methylation variations at CETP and LPL gene promoter loci: new molecular biomarkers associated with blood lipid profile variability

BACKGROUND

Recent findings suggest that DNA methylation, a well-known epigenetic mechanism, is involved in high-density lipoprotein cholesterol (HDL-C) metabolism and increased cardiovascular disease risk. The aim of this study was thus to assess whether DNA methylation within key genes of lipoprotein metabolism is associated with blood lipid profile variability.

METHODS AND RESULTS

Ninety-eight untreated familial hypercholesterolaemia patients (61 men and 37 women) were recruited for leucocyte DNA methylation analyses at the LDLR, CETP, LCAT and LPL gene promoter loci using bisulfite pyrosequencing. LPL DNA methylation was correlated with HDL-C (r = 0.22; p = 0.031) and HDL particle size (r = 0.47, p = 0.013). In both sex, CETP DNA methylation was negatively associated with low-density lipoprotein cholesterol levels (r < -0.32; p < 0.05). In men, CETP DNA methylation was associated with HDL-C (r = -0.36; p = 0.006), HDL-triglyceride levels (r = 0.59; p < 0.001) and HDL particle size (r = -0.44, p = 0.019). In visceral adipose tissue from 30 men with severe obesity, the associations between LPL DNA methylation, HDL-C (r = -0.40; p = 0.03) and LPL mRNA levels (r = -0.61, p < 0.001) were confirmed.

CONCLUSION

CETP and LPL DNA methylation levels are associated with blood lipid profile, suggesting that further studies of epipolymorphisms should most certainly contribute to a better understanding of the molecular bases of dyslipidemia.

The g.-469G>A polymorphism in the GPIHBP1 gene promoter is associated with hypertriglyceridemia and has an additive effect on the risk conferred by LPL defective alleles

BACKGROUND AND AIMS

Hypertriglyceridemia (hyperTG) is a component of the metabolic syndrome and a cardiovascular or pancreatitis risk factor. Although both genetic and environmental factors influence its expression, the biological component of hyperTG is still underestimated and has been reported in 10-20% of cases only. Given its key role in the lipolysis of TG-rich lipoproteins, glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1) is a biological candidate for hyperTG. The aim of this study was to assess the association of new GPIHBP1 gene variants with hyperTG (fasting plasma TG values ≥ 2.0 mmol/L).

METHODS AND RESULTS

Sequencing the GPIHBP1 gene identified a g.-469G > A (rs72691625) polymorphism in the promoter. A sample of 541 Caucasians (263 normoTG and 278 hyperTG) was then screened for this polymorphism using a 5'nuclease TaqMan. In multivariate analyses, GPIHBP1 g.-469G > A polymorphism carriers were at significantly higher risk of hyperTG (≥ 2.0 mmol/L) than non-carriers, the odds ratio (OR) being 1.67 (p = 0.025) among heterozygotes and 5.70 (p = 0.004) in homozygotes. The simultaneous presence of loss-of-function LPL polymorphisms had an incremental additive effect on the risk of hyperTG (OR: 7.30; p < 0.001), highlighting the importance of gene-gene interactions in the expression of hyperTG.

CONCLUSIONS

In this study, the g.-469G >A polymorphism in the GPIHBP1 gene promoter was associated with an increased risk of hyperTG and had an additive effect on the risk conferred by LPL defective alleles.

Dynamic genetic linkage of intermediate blood pressure phenotypes during postural adaptations in a founder population

Blood pressure (BP) is a dynamic phenotype that varies rapidly to adjust to changing environmental conditions. Standing upright is a recent evolutionary trait, and genetic factors that influence postural adaptations may contribute to BP variability. We studied the effect of posture on the genetics of BP and intermediate BP phenotypes. We included 384 sib-pairs in 64 sib-ships from families ascertained by early-onset hypertension and dyslipidemia. Blood pressure, three hemodynamic and seven neuroendocrine intermediate BP phenotypes were measured with subjects lying supine and standing upright. The effect of posture on estimates of heritability and genetic covariance was investigated in full pedigrees. Linkage was conducted on 196 candidate genes by sib-pair analyses, and empirical estimates of significance were obtained. A permutation algorithm was implemented to study the postural effect on linkage. ADRA1A, APO, CAST, CORIN, CRHR1, EDNRB, FGF2, GC, GJA1, KCNB2, MMP3, NPY, NR3C2, PLN, TGFBR2, TNFRSF6, and TRHR showed evidence of linkage with any phenotype in the supine position and not upon standing, whereas AKR1B1, CD36, EDNRA, F5, MMP9, PKD2, PON1, PPARG, PPARGC1A, PRKCA, and RET were specifically linked to standing phenotypes. Genetic profiling was undertaken to show genetic interactions among intermediate BP phenotypes and genes specific to each posture. When investigators perform genetic studies exclusively on a single posture, important genetic components of BP are missed. Supine and standing BPs have distinct genetic signatures. Standardized maneuvers influence the results of genetic investigations into BP, thus reflecting its dynamic regulation.

Efficacy and long-term safety of alipogene tiparvovec (AAV1-LPLS447X) gene therapy for lipoprotein lipase deficiency: an open-label trial

We describe the 2-year follow-up of an open-label trial (CT-AMT-011-01) of AAV1-LPL(S447X) gene therapy for lipoprotein lipase (LPL) deficiency (LPLD), an orphan disease associated with chylomicronemia, severe hypertriglyceridemia, metabolic complications and potentially life-threatening pancreatitis. The LPL(S447X) gene variant, in an adeno-associated viral vector of serotype 1 (alipogene tiparvovec), was administered to 14 adult LPLD patients with a prior history of pancreatitis. Primary objectives were to assess the long-term safety of alipogene tiparvovec and achieve a ≥40% reduction in fasting median plasma triglyceride (TG) at 3-12 weeks compared with baseline. Cohorts 1 (n=2) and 2 (n=4) received 3 × 10(11) gc kg(-1), and cohort 3 (n=8) received 1 × 10(12) gc kg(-1). Cohorts 2 and 3 also received immunosuppressants from the time of alipogene tiparvovec administration and continued for 12 weeks. Alipogene tiparvovec was well tolerated, without emerging safety concerns for 2 years. Half of the patients demonstrated a ≥40% reduction in fasting TG between 3 and 12 weeks. TG subsequently returned to baseline, although sustained LPL(S447X) expression and long-term changes in TG-rich lipoprotein characteristics were noted independently of the effect on fasting plasma TG.

Decreased NKCC1 activity in erythrocytes from African Americans with hypertension and dyslipidemia

BACKGROUND

Recent studies demonstrated a key role of ubiquitous isoform of Na+,K+,2Cl- co-transport (NKCC1) in regulation of myogenic tone and peripheral resistance. We examined the impact of race, gender, and plasma lipid on NKCC1 activity in French Canadians and African Americans with hypertension and dyslipidemia.

METHODS

NKCC and passive erythrocyte membrane permeability to K+, measured as ouabain-resistant, bumetanide-sensitive, and (ouabain+bumetanide)-resistant 86Rb influx, respectively, were compared in 111 French-Canadian men, 107 French-Canadian women, 26 African-American men, and 45 African-American women with essential hypertension and dyslipidemia.

RESULTS

The African-American men and women were 7 years younger and presented twofold decreased plasma triglycerides compared to their French-Canadian counterparts (P < 0.01) whereas body mass index (BMI), total cholesterol, low-density lipoprotein, and high-density lipoprotein (HDL) were not different. NKCC was respectively 50 and 38% lower in the African-American men and women than in the French Canadians (P < 0.005) without any differences in passive erythrocyte membrane permeability for K+. We did not observe any impact of age on NKCC in all groups under investigation, whereas plasma triglycerides correlated positively with the activity of this carrier in the French-Canadian men only.

CONCLUSIONS

NKCC1 activity is lower in erythrocytes of African Americans with essential hypertension and dyslipidemia than in Caucasian counterparts. We suggest that decreased NKCC1 may contribute to the feature of the pathogenesis of salt-sensitive hypertension seen in African Americans.

Managing chronic kidney disease in a nurse-run, physician-monitored clinic: the CanPREVENT experience

The purpose of this study was to examine the nature of the care provided to people with chronic kidney disease within a larger study of nurse-run, physician-monitored clinics, as well as how patients, nurses, and nephrologists described their experience with the clinics. Interviews were conducted with 7 nurses, 5 physicians, and 23 patients. Data collection also entailed review of 40 randomly selected charts. Identified themes related to characteristics of the nurse, patient-centred care, health promotion, teaching, dealing with problems, time, protocols, consultation and referrals, clinic logistics, paperwork/documentation, and nurse-physician collaboration. Challenges and outcomes were also described as part of the experience with the clinic. Patients were actively engaged in self-management and reported high levels of satisfaction with care as well as improvements in selected outcomes. Overall, the perceptions of this model of care were positive and the approach warrants further exploration.