Cost-Effectiveness of Screening Strategies for Familial Hypercholesterolaemia: An Updated Systematic Review

BACKGROUND

OBJECTIVE: This study aimed to systematically synthesise the cost-effectiveness of screening strategies to detect heterozygous familial hypercholesterolemia (FH).

METHODS

We searched seven databases from inception to 2 February , 2023, for eligible cost-effective analysis (CEA) that evaluated screening strategies for FH versus the standard care for FH detection. Independent reviewers performed the screening, data extraction and quality evaluation. Cost results were adapted to 2022 US dollars (US$) to facilitate comparisons between studies using the same screening strategies. Cost-effectiveness thresholds were based on the original study criteria.

RESULTS

A total of 21 studies evaluating 62 strategies were included in this review, most of the studies (95%) adopted a healthcare perspective in the base case, and majority were set in high-income countries. Strategies analysed included cascade screening (23 strategies), opportunistic screening (13 strategies), systematic screening (11 strategies) and population-wide screening (15 strategies). Most of the strategies relied on genetic diagnosis for case ascertainment. The most common comparator was no screening, but some studies compared the proposed strategy versus current screening strategies or versus the best next alternative. Six studies evaluated screening in children while the remaining were targeted at adults. From a healthcare perspective, cascade screening was cost-effective in 78% of the studies [cost-adapted incremental cost-effectiveness ratios (ICERs) ranged from dominant to 2022 US$ 104,877], opportunistic screening in 85% (ICERs from US$4959 to US$41,705), systematic screening in 80% (ICERs from US$2763 to US$69,969) and population-wide screening in 60% (ICERs from US$1484 to US$223,240). The most common driver of ICER identified in the sensitivity analysis was the long-term cost of lipid-lowering treatment.

CONCLUSIONS

Based on reported willingness to pay thresholds for each setting, most CEA studies concluded that screening for FH compared with no screening was cost-effective, regardless of the screening strategy. Cascade screening resulted in the largest health benefits per person tested.

A novel equation for the estimation of low-density lipoprotein cholesterol in the Saudi Arabian population: a derivation and validation study

Low-density lipoprotein cholesterol (LDL-C) is typically estimated by the Friedewald equation to guide atherosclerotic cardiovascular disease (ASCVD) management despite its flaws. Martin-Hopkins and Sampson-NIH equations were shown to outperform Friedewald's in various populations. Our aim was to derive a novel equation for accurate LDL-C estimation in Saudi Arabians and to compare it to Friedewald, Martin-Hopkins and Sampson-NIH equations. This is a cross-sectional study on 2245 subjects who were allocated to 2 cohorts; a derivation (1) and a validation cohort (2). Cohort 1 was analyzed in a multiple regression model to derive an equation (equationD) for estimating LDL-C. The agreement between the measured (LDL-CDM) and calculated levels was tested by Bland-Altman analysis, and the biases by absolute error values. Validation of the derived equation was carried out across LDL-C and triglyceride (TG)-stratified groups. The mean LDL-CDM was 3.10 ± 1.07 and 3.09 ± 1.06 mmol/L in cohorts 1 and 2, respectively. The derived equation is: LDL-CD = 0.224 + (TC × 0.919) - (HDL-C × 0.904) - (TG × 0.236) - (age × 0.001) - 0.024. In cohort 2, the mean LDL-C (mmol/L) was estimated as 3.09 ± 1.06 by equationD, 2.85 ± 1.12 by Friedewald, 2.95 ± 1.09 by Martin-Hopkins, and 2.93 ± 1.11 by Sampson-NIH equations; statistically significant differences between direct and calculated LDL-C was observed with the later three equations (P < 0.001). Bland-Altman analysis showed the lowest bias (0.001 mmol/L) with equationD as compared to 0.24, 0.15, and 0.17 mmol/L with Friedewald, Martin-Hopkins, and Sampson-NIH equations, respectively. The absolute errors in all guideline-stratified LDL-C categories was the lowest with equationD, which also showed the best classifier of LDL-C according to guidelines. Moreover, equationD predicted LDL-C levels with the lowest error with TG levels up to 5.63 mmol/L. EquationD topped the other equations in estimating LDL-C in Saudi Arabians as it could permit better estimation when LDL-C is < 2.4 mmol/L, in familial hyperlipidemia, and in hypertriglyceridemia, which improves cardiovascular outcomes in high-risk patients. We recommend further research to validate equationD in a larger dataset and in other populations.

Influence of triglyceride concentration in lipoprotein (a) as a function of dyslipidemia

BACKGROUND

Recently, an inverse relationship between the blood concentration of lipoprotein(a) (Lp(a)) and triglycerides (TG) has been demonstrated. The larger the VLDL particle size, the greater the presence of VLDL rich in apoliprotein E and in subjects with the apoE2/E2 genotype, the lower Lp(a) concentration. The mechanism of this inverse association is unknown. The objective of this analysis was to evaluate the Lp(a)-TG association in patients treated at the lipid units included in the registry of the Spanish Society of Atherosclerosis (SEA) by comparing the different dyslipidemias.

PATIENTS AND METHODS

Five thousand two hundred and seventy-five subjects ≥18 years of age registered in the registry before March 31, 2023, with Lp(a) concentration data and complete lipid profile information without treatment were included.

RESULTS

The mean age was 53.0 ± 14.0 years, with 48% women. The 9.5% of subjects (n = 502) had diabetes and the 22.4% (n = 1184) were obese. The median TG level was 130 mg/dL (IQR 88.0-210) and Lp(a) 55.0 nmol/L (IQR 17.9-156). Lp(a) concentration showed a negative association with TG concentration when TG values exceeded 300 mg/dL. Subjects with TG > 1000 mg/dL showed the lowest level of Lp(a), 17.9 nmol/L, and subjects with TG < 300 mg/dL had a mean Lp(a) concentration of 60.1 nmol/L. In subjects without diabetes or obesity, the inverse association of Lp(a)-TG was especially important (p < 0.001). The median Lp(a) was 58.3 nmol/L in those with TG < 300 mg/dL and 22.0 nmol/L if TG > 1000 mg/dL. No association was found between TG and Lp(a) in subjects with diabetes and obesity, nor in subjects with familial hypercholesterolemia. In subjects with multifactorial combined hyperlipemia with TG < 300 mg/dL, Lp(a) was 64.6 nmol/L; in the range of 300-399 mg/dL of TG, Lp(a) decreased to 38. 8 nmol/L, and up to 22.3 nmol/L when TG > 1000 mg/dL.

CONCLUSIONS

Our results show an inverse Lp(a)-TG relationship in TG concentrations > 300 mg/dL in subjects without diabetes, obesity and without familial hypercholesterolemia. Our results suggest that, in those hypertriglyceridemias due to hepatic overproduction of VLDL, the formation of Lp(a) is reduced, unlike those in which the peripheral catabolism of TG-rich lipoproteins is reduced.

Role of statins in the management of dyslipidaemia

Blood cholesterol has firmly been established as a crucial risk factor for the development of atherosclerotic cardiovascular disease (ASCVD) by elegant epidemiological studies. Naturally, means to reduce blood cholesterol level took the centerstage of research in this field. After initial lukewarm results with nicotinic acid, fibrates and some other agents, statins emerged as the most effective class of medicine to reduce blood cholesterol; in particular, the most atherogenic low density lipoprotein cholesterol (LDL-C). Also, they are very safe and well tolerated. As ASCVD comes in various stages, statins have also been tried in different settings, e.g., primary prevention, secondary prevention, as part of coronary intervention strategy, familial hypercholesterolemia, etc. Almost in all clinical scenarios, statins proved themselves to impart clinical benefit. Though side effects of statins are outweighed by their benefits, nonetheless clinicians should detect the side effects early to avoid major problems.

Spatial lipidomics of coronary atherosclerotic plaque development in a familial hypercholesterolemia swine model

Coronary atherosclerosis is caused by plaque build-up, with lipids playing a pivotal role in its progression. However, lipid composition and distribution within coronary atherosclerosis remain unknown. This study aims to characterize lipids and investigate differences in lipid composition across disease stages to aid in the understanding of disease progression. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) was used to visualize lipid distributions in coronary artery sections (n = 17) from hypercholesterolemic swine. We performed histology on consecutive sections to classify the artery segments and to investigate colocalization between lipids and histological regions of interest in advanced plaque, including necrotic core and inflammatory cells. Segments were classified as healthy (n = 6), mild (n = 6), and advanced disease (n = 5) artery segments. Multivariate data analysis was employed to find differences in lipid composition between the segment types, and the lipids' spatial distribution was investigated using non-negative matrix factorization (NMF). Through this process, MALDI-MSI detected 473 lipid-related features. NMF clustering described three components in positive ionization mode: triacylglycerides (TAG), phosphatidylcholines (PC), and cholesterol species. In negative ionization mode, two components were identified: one driven by phosphatidylinositol(PI)(38:4), and one driven by ceramide-phosphoethanolamine(36:1). Multivariate data analysis showed the association between advanced disease and specific lipid signatures like PC(O-40:5) and cholesterylester(CE)(18:2). Ether-linked phospholipids and LysoPC species were found to colocalize with necrotic core, and mostly CE, ceramide, and PI species colocalized with inflammatory cells. This study, therefore, uncovers distinct lipid signatures correlated with plaque development and their colocalization with necrotic core and inflammatory cells, enhancing our understanding of coronary atherosclerosis progression.

Membrane Transporter of Serotonin and Hypercholesterolemia in Children

The serotonin membrane transporter is one of the main mechanisms of plasma serotonin concentration regulation. Serotonin plays an important role in the pathogenesis of various cardiovascular diseases, stimulating the proliferation of smooth muscle cells, key cells in the process of hypertrophic vascular remodeling. Vascular remodeling is one of the leading prognostically unfavorable factors of atherosclerosis, the main manifestation of familial hypercholesterolemia. Familial hypercholesterolemia is one of the most common genetically determined lipid metabolism disorders and occurs in 1 in 313 people. The aim of our study was to investigate the levels of plasma and platelet serotonin, 5-hydroxyindoleacetic acid, and membrane transporter in a cross-sectional study of two pediatric groups, including patients with familial hypercholesterolemia and the control group, which consisted of apparently healthy children without cardiovascular diseases. The study involved 116 children aged 5 to 17 years old. The proportion of boys was 50% (58/116) and the average age of the children was 10.5 years (CI 2.8-18.1). The concentrations of serotonin in blood plasma and platelets and 5-hydroxyindoleacetic acid were higher in children with familial hypercholesterolemia than in the controls. The concentration of the serotonin transporter in platelets in healthy children, compared with the main group, was 1.3 times higher. A positive correlation was revealed between the level of serotonin (5-HT and PWV: ρ = 0.6, p < 0.001), its transporter (SERT and PWV: ρ = 0.5, p < 0.001), and the main indicators of arterial vascular stiffness. Our study revealed the relationship between high serotonin and SERT concentrations and markers of arterial stiffness. The results we obtained suggest the involvement of serotonin and SERT in the process of vascular remodeling in familial hypercholesterolemia in children.

Causal effects of circulating lipids and lipid-lowering drugs on the risk of urinary stones: a Mendelian randomization study

Background

Previous studies have yielded conflicting findings regarding the association between circulating lipids and lipid-lowering drugs with urinary stones, and the causal relationship between the two remains inconclusive.

Objective

This study aimed to assess the causal relationship between circulating lipids (Triglycerides [TG], low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], apolipoprotein A [APOA], apolipoprotein B [APOB] and Pure hypercholesterolaemia), lipid-lowering drugs (HMGCR [HMG-CoA reductase] inhibitors and PCSK9[Proprotein Convertase Subtilisin/Kexin Type 9] inhibitors) and the risk of urinary stones, using genetic data.

Methods

Genetic instrumental variables (GIVs) for circulating lipids and lipid-lowering drugs were obtained from the UK Biobank and existing literature. Outcome data were extracted from a genetic association database with 3,625 urinary stone cases and 459,308 controls. Two-sample MR analysis, employing the TwoSampleMR software package in R 4.2.3, was conducted to assess the associations between multiple exposures. The primary outcome was determined using the inverse variance weighted (IVW) method for the causal relationship between exposure and outcome, while additional methods such as MR-Egger, weighted median, simple mode, and weighted mode were utilized as supplementary analyses. Robustness of the Mendelian Randomization (MR) analysis results was assessed through leave-one-out analysis and funnel plots.

Results

The MR analysis revealed a significant association between elevated TG levels per 1 standard deviation and the occurrence of urinary stones (odds ratio [OR]: 1.002, 95% confidence interval [CI]: 1.000-1.003, P = 0.010). However, no significant association was observed between factors other than TG exposure and the risk of urinary stone occurrence across all methods(LDL-C: [OR], 1.001; 95% [CI], 1.000-1.003, P=0.132;HDL-C: [OR], 0.999; 95% [CI], 0.998-1.000, P=0.151;APOA:[OR] being 1.000 (95% [CI], 0.999-1.001, P=0.721;APOB: [OR] of 1.001 (95% [CI], 1.000-1.002, P=0.058;Pure hypercholesterolaemia: [OR] of 1.015 (95% [CI], 0.976-1.055, P=0.455) and lipid-lowering drugs (HMGCR inhibitors: [OR], 0.997; 95% [CI], 0.990-1.003, P=0.301 and PCSK9 inhibitors:[OR], 1.002; 95% [CI], 1.000-1.005, P=0.099).

Conclusion

Our findings provide conclusive evidence supporting a causal relationship between an increased risk of urinary stones and elevated serum TG levels. However, we did not find a significant association between urinary stone occurrence and the levels of LDL-C, HDL-C, APOA, APOB, Pure hypercholesterolaemia and lipid-lowering drugs.

Sex differences in lipids: A life course approach

Differences between men and women in lipids and lipoproteins are observed in distribution and trajectory from infancy to adulthood in the general population. However, these differences are more pronounced in hereditary lipid disorders such as familial hypercholesterolemia (FH) when absolute cholesterol levels are higher from birth onwards. In the early life course, girls compared to boys have higher low-density lipoprotein cholesterol (LDL-C) levels and total cholesterol, while high-density lipoprotein cholesterol (HDL-C) levels are similar. In early adulthood to middle-age, women have lower LDL-C and higher HDL-C levels, as LDL-C levels increase and HDLC levels decrease in men. In the elderly, all lipids - total cholesterol, LDL-C, HDL-C and triglyceride levels decrease but are more pronounced in men. Lipid levels are also affected by specific transitions in girls/women such as the menstrual cycle, pregnancy, breastfeeding and menopause. Lipid levels fluctuate during the menstrual cycle. During pregnancy a physiological increase of LDL-C and even a larger increase in triglyceride levels are observed. Pregnancy has a double impact on LDL-C accumulation in women with FH as they have to stop statins, and the absolute increase in LDL-C is higher than in women without FH. In the menopausal transition, women develop a more adverse lipid profile. Therefore, it is important to take into account both sex and the life course when assessing a lipid profile.

Determinants of lipid clinic referral and attendance in a multi-ethnic adult population in south London: a cross-sectional study

BACKGROUND

Primary dyslipidaemias, including familial hypercholesterolaemia, are underdiagnosed genetic disorders that substantially increase risk for premature coronary artery disease in adults. Early identification of primary dyslipidaemias via lipid clinic referral optimises patient management and enables cascade screening of relatives. Improving the identification of primary dyslipidaemias, and understanding disparities in ascertainment and management, is an NHS priority. We aimed to assess determinants of lipid clinic referral or attendance (LCR) in ethnically diverse adults.

METHODS

We did a retrospective cross-sectional study using the Lambeth DataNet containing anonymised data from 41 general practitioner (GP) practices in south London. We looked at referral data for adult patients aged 18 years and older from Jan 1, 1995, until May 14, 2018. LCR was the main outcome. We used sequential multilevel logistic regression models adjusted for practice effects to estimate the odds of LCR assessed across six ethnic groups (reference group White) and patient-level factors (demographic, socioeconomic, lifestyle, comorbidities, total cholesterol [TC] >7·5mmol/L, statin prescription, and practice factors). The study was approved by NHS South East London Clinical Commissioning Group (CCG) and NHS Lambeth CCG.

FINDINGS

780 (0·23%) of 332 357 adult patients were coded as referred (n=538) or seen (n=252) in a lipid clinic. 164 487 (46·49%) were women (appendix). The fully adjusted model for odds of LCR showed the following significant associations for age (odds ratio [OR] 0·96, 95% CI 0·96-0·97, p<0·001); Black, African, Caribbean, or Black-British ethnicity (0·67, 0·53-0·84, p=0·001); ex-smoker status (1·29, 1·05-1·57, p=0·014); TC higher than 7·5 mmol/L (12·18, 9·60-15·45, p<0·001); statin prescription (14·01, 10·85-18·10, p<0·001); diabetes (0·72, 0·58-0·91, p=0·005); high-frequency GP attendance at seven or more GP consultations in the past year (1·49, 1·21-1·84, p<0·001); high GP-density (0·5-0·99 full-time equivalent GPs per 1000 patients; 2·70, 1·23-5·92, p=0·013). Sensitivity analyses for LCR restricted to familial hypercholesterolaemia-coded patients (n=581) found associations with TC higher than 7·5 mmol/L (4·26, 1·89-9·62, p<0·001), statin prescription (16·96, 2·19-131·36, p=0·007), and high GP-density (5·73, 1·27-25·93, p=0·023), with no significant associations with ethnicity. The relative contribution of GP practices to LCR was 6·32% of the total variance. There were no significant interactions between ethnicity and deprivation, age, or obesity.

INTERPRETATION

While interpretation is limited by the accuracy and completeness of coded records, the study showed factors associated with a higher likelihood of LCR included individuals recorded as having TC higher than 7·5 mmol/L, statin prescription, ex-smoker status, high-frequency GP attendance, and registration at a GP practice with 0·5-0·99 GP density. Patients with increasing age; Black, African, Caribbean, or Black-British ethnicity patients; and patients with diabetes had lower odds of LCR. Finally, the difference in odds of LCR between Black and White patients highlights potential health inequalities.

FUNDING

NHS Race & Health Observatory.

Decreased Serum Stromal Cell-Derived Factor-1 in Patients with Familial Hypercholesterolemia and Its Strong Correlation with Lipoprotein Subfractions

Stromal cell-derived factor-1 (SDF-1) is a chemokine that exerts multifaceted roles in atherosclerosis. However, its association with hyperlipidemia is contradictory. To date, serum SDF-1 and its correlations with lipid fractions and subfractions in heterozygous familial hypercholesterolemia (HeFH) have not been investigated. Eighty-one untreated patients with HeFH and 32 healthy control subjects were enrolled in the study. Serum SDF-1, oxidized LDL (oxLDL) and myeloperoxidase (MPO) were determined by ELISA. Lipoprotein subfractions were detected by Lipoprint. We diagnosed FH using the Dutch Lipid Clinic Network criteria. Significantly lower serum SDF-1 was found in HeFH patients compared to healthy controls. Significant negative correlations were detected between serum total cholesterol, triglycerides, LDL-cholesterol (LDL-C), apolipoprotein B100 (ApoB100) and SDF-1. Furthermore, serum SDF-1 negatively correlated with VLDL and IDL, as well as large LDL and large and intermediate HDL subfractions, while there was a positive correlation between mean LDL-size, small HDL and SDF-1. SDF-1 negatively correlated with oxLDL and MPO. A backward stepwise multiple regression analysis showed that the best predictors of serum SDF-1 were VLDL and oxLDL. The strong correlation of SDF-1 with lipid fractions and subfractions highlights the potential common pathways of SDF-1 and lipoprotein metabolism, which supports the role of SDF-1 in atherogenesis.

[Hypercholesterolemia - who, when, how to treat?]

In recent years, clinical scientific data on LDL cholesterol and atherosclerosis has led to lowering of LDL-C targets and the expansion of the indication for lipid drug therapy to larger populations or patients. The calculators SCORE2 and SCORE-OP were newly developed to calculate the cardiovascular risk in primary prevention. When assessing the cardiovascular risk of patients, in addition to e.g., pre-existing cardiovascular disease, familial hypercholesterolaemia and type II diabetes, type I diabetes, diabetic complications, renal insufficiency and subclinical arteriosclerosis are also considered. Statins are the basic therapy for hypercholesterolemia. Alternative medication are ACL inhibitors e.g., Bempedoic acid and Inclisiran which represent new drug therapy options for statin intolerance. Nevertheless, a dietary intervention belongs at the beginning of every lipid-lowering therapy.

Association between Eating Patterns and Quality of Life in Patients with Familial Hypercholesterolemia

(1) Background: Familial hypercholesterolemia (FH) is a genetic disease that has autosomal dominant inheritance, being characterized by increased levels of low-density lipoproteins (LDLs) due to a decreased clearance of the circulant LDLs. Alimentation is a key factor in patients with FH. Implementing a restrictive diet may have a significant impact on their quality of life, besides the social and environmental factors. (2) Methods: We realized a prospective study that was conducted in the Cardiovascular Rehabilitation Clinic from the Clinical Rehabilitation Hospital and that included 70 patients with FH and 20 controls (adults with no comorbidities). We evaluated their lipid profile, their quality of life through the Short Form-36 Questionnaire, and their eating habits. (3) Results: Lower scores in the quality-of-life questionnaire were obtained in the FH group both in the case of the physical (73.06 vs. 87.62) and the mental component (75.95 vs. 83.10). Women had better physical function (85 vs. 75) and physical role than men (100 vs. 75). The group aged over 65 has the score lowest for all 10 components. Overeating was driven by boredom and was more frequent on weekends in the FH group. None of the patients in the control group felt loneliness or depression associated with overeating. (4) Conclusions: Overeating in patients with FH is associated with a lower quality of life. The complexity of these patients needs a multidisciplinary approach. Thus, the quality-of-life questionnaire should be implemented in their periodic follow-ups in order to increase their general status, paying special attention to geriatric patients.

Algorithms for Treating Dyslipidemia in Youth

PURPOSE OF REVIEW

The goal of this article is to review algorithms for treating dyslipidemia in youth, discuss pitfalls, propose enhanced algorithms to address pitfalls, and consider future directions.

RECENT FINDINGS

The presence of modifiable and non-modifiable cardiovascular disease (CVD) risk factors during childhood is associated with CVD-related events in adulthood. Recent data has shown that childhood initiation of statin therapy in youth < 18 years of age with familial hypercholesterolemia reduces the risk of adult CVD. However, pediatric dyslipidemia remains undertreated in part due to a lack of primary health care providers with adequate understanding of screening guidelines and pediatric lipidologists with experience in treatment and follow-up of this unique population. Management algorithms have been published by the National Heart, Lung, and Blood Institute and American Heart Association as tools to empower clinicians to manage dyslipidemia. We propose enhanced algorithms, which incorporate recently approved pharmacotherapy to address the management gaps. Future algorithms based upon clinical risk scores may enhance treatment and improve outcomes. Algorithms for dyslipidemia management which target youth < 18 years of age are tools which empower clinicians to manage dyslipidemia in this unique population. Enhanced algorithms may help address pitfalls. We acknowledge the need for further risk assessment tools in pediatrics for tailored dyslipidemia management.

[Actual nutrition in adults with familial hypercholesterolemia]

Familial hypercholesterolemia (FH) is a highly atherogenic, genetically based lipid disorder. For patients with FH, dietary modification is the cornerstone of complex lipidlowering therapy. The aim of the research was to assess the actual nutrition in adults with familial hypercholesterolemia. Material and methods. The study included 100 patients over 18 years old (including 46% men) with "probable" or "definite" FH according to the Dutch Lipid Clinic Network or Simon Broome criteria from the GENMOTIV-FH study (ClinicalTrials: NCT04656028) in 2019-2021. Actual nutrition was assessed using the 24-hour dietary recall method. The frequency of the main meal groups' consumption and food-related behavior were assessed using a questionnaire method. The data are presented as the median [Q25; Q75]. Results. The study showed the excess consumption of protein (19.3 [16.7; 24.0] in men and 18.6% [13.6; 24.3] in women, p=0.592), total fat (35.1 [29.4; 41.0] in men vs 39.2% [33.2; 47.5] in women, p=0.018), including saturated fatty acids (9.6 [4.7; 13.0] vs 10.4% [7.5; 14.2], respectively, p=0.151), and cholesterol (265.8 [188.8; 521.9] mg/day in men vs 282.1 [147.2; 542.8] mg/day in women, p=0.936). Consumption of total carbohydrates (44.3 [37.2; 50.0] vs 39.6% [30.1; 48.8], respectively, p=0.100) and fiber (10.7 [7.3; 13.3] g/day in men vs 11.5 [7.9; 13.9] g/day in women, p=0.372) was insufficient. Only 47.9% of patients consumed vegetables daily, 39.1% - fruits and berries. The majority (64.5%) of patients with FH preferred high-fat cheese (>=25%). Cottage cheese of >=5% fat content preferred 52.7% of patients. The daily poultry consumption was more than red meat (19.3 vs 4.3% respectively, p=0.003). Regularly included fish in their meal 53.8% of patients. Conclusion. The actual nutrition in adults with FH does not match international guidelines. The results highlight the importance of dietary interventions for patients with FH.

Population Genomic Screening for Three Common Hereditary Conditions : A Cost-Effectiveness Analysis

BACKGROUND

The cost-effectiveness of screening the U.S. population for Centers for Disease Control and Prevention (CDC) Tier 1 genomic conditions is unknown.

OBJECTIVE

To estimate the cost-effectiveness of simultaneous genomic screening for Lynch syndrome (LS), hereditary breast and ovarian cancer syndrome (HBOC), and familial hypercholesterolemia (FH).

DESIGN

Decision analytic Markov model.

DATA SOURCES

Published literature.

TARGET POPULATION

Separate age-based cohorts (ages 20 to 60 years at time of screening) of racially and ethnically representative U.S. adults.

TIME HORIZON

Lifetime.

PERSPECTIVE

U.S. health care payer.

INTERVENTION

Population genomic screening using clinical sequencing with a restricted panel of high-evidence genes, cascade testing of first-degree relatives, and recommended preventive interventions for identified probands.

OUTCOME MEASURES

Incident breast, ovarian, and colorectal cancer cases; incident cardiovascular events; quality-adjusted survival; and costs.

RESULTS OF BASE-CASE ANALYSIS

Screening 100 000 unselected 30-year-olds resulted in 101 (95% uncertainty interval [UI], 77 to 127) fewer overall cancer cases and 15 (95% UI, 4 to 28) fewer cardiovascular events and an increase of 495 quality-adjusted life-years (QALYs) (95% UI, 401 to 757) at an incremental cost of $33.9 million (95% UI, $27.0 million to $41.1 million). The incremental cost-effectiveness ratio was $68 600 per QALY gained (95% UI, $41 800 to $88 900).

RESULTS OF SENSITIVITY ANALYSIS

Screening 30-, 40-, and 50-year-old cohorts was cost-effective in 99%, 88%, and 19% of probabilistic simulations, respectively, at a $100 000-per-QALY threshold. The test costs at which screening 30-, 40-, and 50-year-olds reached the $100 000-per-QALY threshold were $413, $290, and $166, respectively. Variant prevalence and adherence to preventive interventions were also highly influential parameters.

LIMITATIONS

Population averages for model inputs, which were derived predominantly from European populations, vary across ancestries and health care environments.

CONCLUSION

Population genomic screening with a restricted panel of high-evidence genes associated with 3 CDC Tier 1 conditions is likely to be cost-effective in U.S. adults younger than 40 years if the testing cost is relatively low and probands have access to preventive interventions.

PRIMARY FUNDING SOURCE

National Human Genome Research Institute.

Does low-density lipoprotein fully explain atherosclerotic risk in familial hypercholesterolemia?

PURPOSE OF REVIEW

Familial hypercholesterolemia (FH) is a monogenic disorder of elevated low-density lipoprotein cholesterol (LDL-C) from birth leading to increased risk for atherosclerotic cardiovascular disease. However, not all carriers of FH variants display an FH phenotype. Despite this fact, FH variants confer increased risk for atherosclerotic disease in population cohorts. An important question to consider is whether measurements of LDL-C can fully account for this risk.

RECENT FINDINGS

The atherosclerotic risk associated with FH variants is independent of observed adult LDL-C levels. Modeling adult longitudinal LDL-C accounts for more of this risk compared to using a single measurement. Still, even when adjusting for observed longitudinal LDL-C in adult cohorts, FH variant carriers are at increased risk for coronary artery disease. Genetic analyses, observational studies, and clinical trials all suggest that cumulative LDL-C is a critical driver of cardiovascular risk that may not be fully appreciated by routine LDL-C measurements in adulthood. As such, FH variants confer risk independent of adult LDL-C because these variants increase cumulative LDL-C exposure starting from birth.

SUMMARY

Both research and clinical practice focus on LDL-C measurements in adults, but measurements during adulthood do not reflect lifelong cumulative exposure to LDL-C. Genetic assessments may compliment clinical assessments by better identifying patients who have experienced greater longitudinal LDL-C exposure.

Gene and cell therapy approaches for familial hypercholesterolemia: An update

Familial hypercholesterolemia (FH) is a common autosomal codominant hereditary illness marked by the heightened risk of early atherosclerotic cardiovascular disease and high blood levels of low-density lipoprotein cholesterol (LDL-C). FH patients can have homozygous or heterozygous variants. This condition has been linked to variations in the genes for the LDL receptor (LDLR), apolipoprotein B, proprotein convertase subtilisin/Kexin 9 (PCSK9), and LDLR adaptor protein 1. Drugs such as statins, ezetimibe, and PCSK9 inhibitors are currently widely available, allowing for the theoretical normalization of plasma LDL-C levels mostly in patients with heterozygous FH. However, homozygous FH patients usually have a poor response to traditional lipid-lowering therapy and may have a poor prognosis at a young age. LDL apheresis and novel pharmacological therapies such as microsomal transfer protein inhibitors or anti-angiopoietin-like protein 3 monoclonal antibodies are extremely expensive and unavailable in most regions of the world. Therefore, the unmet need persists for these patients. In this review, we discuss the numerous gene delivery, gene editing, and stem cell manipulation techniques used in this study to correct FH-causing LDLR gene variations in vitro, ex vivo, and in vivo. Finally, we looked at a variety of studies that corrected genetic defects that caused FH using the ground-breaking clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) gene editing technology.

Insulin-like growth factor 1 reduces coronary atherosclerosis in pigs with familial hypercholesterolemia

Although murine models of coronary atherosclerotic disease have been used extensively to determine mechanisms, limited new therapeutic options have emerged. Pigs with familial hypercholesterolemia (FH pigs) develop complex coronary atheromas that are almost identical to human lesions. We reported previously that insulin-like growth factor 1 (IGF-1) reduced aortic atherosclerosis and promoted features of stable plaque in a murine model. We administered human recombinant IGF-1 or saline (control) in atherosclerotic FH pigs for 6 months. IGF-1 decreased relative coronary atheroma in vivo (intravascular ultrasound) and reduced lesion cross-sectional area (postmortem histology). IGF-1 increased plaque's fibrous cap thickness, and reduced necrotic core, macrophage content, and cell apoptosis, consistent with promotion of a stable plaque phenotype. IGF-1 reduced circulating triglycerides, markers of systemic oxidative stress, and CXCL12 chemokine levels. We used spatial transcriptomics (ST) to identify global transcriptome changes in advanced plaque compartments and to obtain mechanistic insights into IGF-1 effects. ST analysis showed that IGF-1 suppressed FOS/FOSB factors and gene expression of MMP9 and CXCL14 in plaque macrophages, suggesting possible involvement of these molecules in IGF-1's effect on atherosclerosis. Thus, IGF-1 reduced coronary plaque burden and promoted features of stable plaque in a pig model, providing support for consideration of clinical trials.

The low-density lipoprotein receptor-mTORC1 axis coordinates CD8+ T cell activation

Activation of T cells relies on the availability of intracellular cholesterol for an effective response after stimulation. We investigated the contribution of cholesterol derived from extracellular uptake by the low-density lipoprotein (LDL) receptor in the immunometabolic response of T cells. By combining proteomics, gene expression profiling, and immunophenotyping, we described a unique role for cholesterol provided by the LDLR pathway in CD8+ T cell activation. mRNA and protein expression of LDLR was significantly increased in activated CD8+ compared to CD4+ WT T cells, and this resulted in a significant reduction of proliferation and cytokine production (IFNγ, Granzyme B, and Perforin) of CD8+ but not CD4+ T cells from Ldlr -/- mice after in vitro and in vivo stimulation. This effect was the consequence of altered cholesterol routing to the lysosome resulting in a lower mTORC1 activation. Similarly, CD8+ T cells from humans affected by familial hypercholesterolemia (FH) carrying a mutation on the LDLR gene showed reduced activation after an immune challenge.

[A practitioner's perspective of the latest lipid guidelines]

The latest ESC recommendations propose several interesting new concepts for the practitioner. The recommendations distinguish between the «apparently healthy» patient and the patient at specific cardiovascular risk (diabetes, renal failure, and familial hypercholesterolemia). New risk calculation tools are proposed (SCORE2 and SCORE2-OP). The proposed LDL-C targets are specific to each group, as a general rule, < 1.8 mmol/l for individuals at high risk and < 1.4 mmol/l for individuals at very high risk. Presence of risk modifiers, comorbidities and patient preferences modulates therapeutic approach which is usually based on optimizing lifestyle and statin medication when necessary.

Multiparametric platform for profiling lipid trafficking in human leukocytes

Systematic insight into cellular dysfunction can improve understanding of disease etiology, risk assessment, and patient stratification. We present a multiparametric high-content imaging platform enabling quantification of low-density lipoprotein (LDL) uptake and lipid storage in cytoplasmic droplets of primary leukocyte subpopulations. We validate this platform with samples from 65 individuals with variable blood LDL-cholesterol (LDL-c) levels, including familial hypercholesterolemia (FH) and non-FH subjects. We integrate lipid storage data into another readout parameter, lipid mobilization, measuring the efficiency with which cells deplete lipid reservoirs. Lipid mobilization correlates positively with LDL uptake and negatively with hypercholesterolemia and age, improving differentiation of individuals with normal and elevated LDL-c. Moreover, combination of cell-based readouts with a polygenic risk score for LDL-c explains hypercholesterolemia better than the genetic risk score alone. This platform provides functional insights into cellular lipid trafficking and has broad possible applications in dissecting the cellular basis of metabolic disorders.

Approaches to Visualising Endocytosis of LDL-Related Lipoproteins

Endocytosis is the process by which molecules are actively transported into cells. It can take on a variety of forms depending on the cellular machinery involved ranging from specific receptor-mediated endocytosis to the less selective and actin-driven macropinocytosis. The plasma lipoproteins, which deliver lipids and other cargo to cells, have been intensely studied with respect to their endocytic uptake. One of the first molecules to be visualised undergoing endocytosis via a receptor-mediated, clathrin-dependent pathway was low-density lipoprotein (LDL). The LDL molecule has subsequently been shown to be internalised through multiple endocytic pathways. Dissecting the pathways of lipoprotein endocytosis has been crucial to understanding the regulation of plasma lipid levels and how lipids enter cells in the arterial wall to promote atherosclerosis. It has also aided understanding of the dysregulation that occurs in plasma lipid levels when molecules involved in uptake are defective, as is the case in familial hypercholesterolemia (FH). The aim of this review is to outline the many endocytic pathways utilised for lipoprotein uptake. It explores the various experimental approaches that have been applied to visualise lipoprotein endocytosis with an emphasis on LDL and its more complex counterpart, lipoprotein(a) [Lp(a)]. Finally, we look at new developments in lipoprotein visualisation that hold promise for scrutinising endocytic pathways to finer detail in the future.

Lipid management across Europe in the real-world setting: a rapid evidence review

OBJECTIVE

To provide a contemporary overview of recent real-world lipid-lowering therapy (LLT) practices and outcomes in patients with hypercholesterolemia/dyslipidemia at high/very high risk of atherosclerotic cardiovascular disease in Europe.

METHODS

A structured literature review of recent (July 2015-July 2020) real-world studies reporting lipid management and outcomes was conducted using a rapid evidence synthesis. Outcomes included patient characteristics, LLT treatment practices, adherence and low-density lipoprotein cholesterol (LDL-C) goal attainment.

RESULTS

Fifty-three real-world observational studies in high/very high risk patients were selected after screening 5664 records (n = 50 national [sample size range 38-237,279] and n = 3 multinational studies [sample size range 6648-8456]). Mean age ranged from 33 to 77 years; hypertension, diabetes and obesity were commonly reported comorbidities. Statins were the most common LLT; patients without familial hypercholesterolemia (FH) mostly received high or moderate intensity statins/LLT, while patients with FH mostly received high intensity statins/LLT. The proportion of patients receiving ezetimibe was low overall (ezetimibe + statin use in those with and without familial hypercholesterolemia [FH] range 5%-59% and 1%-22%, respectively). Overall, the use of proprotein convertase subtilisin/kexin 9 inhibitor (PCSK9i) therapy was limited. Adherence to LLT therapies was defined variably and ranged from 46%-92%. LDL-C goal attainment was suboptimal, irrespective of LLT (overall range in goal attainment with oral LLT was 2%-73% [FH: 2%-23%] and with PCSK9i was 20%-65%).

CONCLUSIONS

LDL-C control is suboptimal and the available LLT armamentarium, most importantly combination therapy, is being underutilized in high/very high risk patients leading to inadequate management of cardiovascular risk.

Dietary Recommendations for Familial Hypercholesterolaemia: an Evidence-Free Zone

We have evaluated dietary recommendations for people diagnosed with familial hypercholesterolaemia (FH), a genetic condition in which increased low-density lipoprotein cholesterol (LDL-C) is associated with an increased risk for coronary heart disease (CHD). Recommendations for FH individuals have emphasised a low saturated fat, low cholesterol diet to reduce their LDL-C levels. The basis of this recommendation is the 'diet-heart hypothesis', which postulates that consumption of food rich in saturated fat increases serum cholesterol levels, which increases risk of CHD. We have challenged the rationale for FH dietary recommendations based on the absence of support for the diet-heart hypothesis, and the lack of evidence that a low saturated fat, low cholesterol diet reduces coronary events in FH individuals. As an alternative approach, we have summarised research which has shown that the subset of FH individuals that develop CHD exhibit risk factors associated with an insulin-resistant phenotype (elevated triglycerides, blood glucose, haemoglobin A1c (HbA1c), obesity, hyperinsulinaemia, high-sensitivity C reactive protein, hypertension) or increased susceptibility to develop coagulopathy. The insulin-resistant phenotype, also referred to as the metabolic syndrome, manifests as carbohydrate intolerance, which is most effectively managed by a low carbohydrate diet (LCD). Therefore, we propose that FH individuals with signs of insulin resistance should be made aware of the benefits of an LCD. Our assessment of the literature provides the rationale for clinical trials to be conducted to determine if an LCD would prove to be effective in reducing the incidence of coronary events in FH individuals which exhibit an insulin-resistant phenotype or hypercoagulation risk.

Use and persistence of lipid-lowering therapy in patients with severe hypercholesterolemia: A prospective study

INTRODUCTION

Statins are the first line of treatment in patients with severe hypercholesterolemia (SH). However, despite the knowledge regarding its effectiveness and security for preventing cardiovascular diseases, treatment is a major challenge.

MATERIAL AND METHODS

A prospective observational study was conducted by telephone survey to determine cardiovascular risk factors, annual monitoring, statins use and persistence and new-onset cardiovascular events (CVE) after 5 years in patients with SH including in a program for detection of familial hypercholesterolemia.

RESULTS

115 participants were analysed, the median age was 56 ±10 being 74% females. 63.4% of women and 43% of men had been correctly controlled in the last year. Patients on lipid lowering drugs stratified by sex was 38.8% in women and 26.7% in men, however, only 22 participants (31.8%) were persistence with statins since 2015.Overall, 48% of the patients presented a CVE and 3.4% died. Multivariate analysis did not reveal predictors for CVE.

CONCLUSIONS

In our population with SH we found a high risk to present a CVE and a dramatic low use and persistence with the treatment.

APOE gene variants in primary dyslipidemia

Apolipoprotein E (apoE) is a major apolipoprotein involved in lipoprotein metabolism. It is a polymorphic protein and different isoforms are associated with variations in lipid and lipoprotein levels and thus cardiovascular risk. The isoform apoE4 is associated with an increase in LDL-cholesterol levels and thus a higher cardiovascular risk compared to apoE3. Whereas, apoE2 is associated with a mild decrease in LDL-cholesterol levels. In the presence of other risk factors, apoE2 homozygotes could develop type III hyperlipoproteinemia (familial dysbetalipoproteinemia or FD), an atherogenic disorder characterized by an accumulation of remnants of triglyceride-rich lipoproteins. Several rare APOE gene variants were reported in different types of dyslipidemias including FD, familial combined hyperlipidemia (FCH), lipoprotein glomerulopathy and bona fide autosomal dominant hypercholesterolemia (ADH). ADH is characterized by elevated LDL-cholesterol levels leading to coronary heart disease, and due to molecular alterations in three main genes: LDLR, APOB and PCSK9. The identification of the APOE-p.Leu167del variant as the causative molecular element in two different ADH families, paved the way to considering APOE as a candidate gene for ADH. Due to non mendelian interacting factors, common genetic and environmental factors and perhaps epigenetics, clinical presentation of lipid disorders associated with APOE variants often strongly overlap. More studies are needed to determine the spectrum of APOE implication in each of the diseases, notably ADH, in order to improve clinical and genetic diagnosis, prognosis and patient management. The purpose of this review is to comment on these APOE variants and on the molecular and clinical overlaps between dyslipidemias.

[Long-lasting LDL-C lowering: silence at last]

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is responsible for the degradation of the LDL-receptor. Inclisiran is a new synthetic interfering ribonucleic acid (siRNA) lowers LDL-cholesterol (LDL-C) levels in the blood by using RNA silencing technology to reduce the production of PCSK9. Inclisiran administered subcutaneously at 0 and 3 months, and then every 6 months has been shown to reduce LDL-C by approximately 50 % in patients at high and very-high cardiovascular risk, or with a diagnosis of familial hypercholesterolemia, but also in patients intolerant to statins. New data are expected, in particular with cardiovascular clinical endpoints, as well as safety for use in adolescents.

Novel behavioural approaches and implementation science for mitigating genetic risk of cardiovascular disease due to elevated lipoprotein(a)

PURPOSE OF REVIEW

Elevated lipoprotein(a) [Lp(a)] is a genetic trait that indicates higher risk of atherosclerotic cardiovascular disease (ASCVD). We review novel strategies to mitigate behavioural risk-factors in this genetic condition.

RECENT FINDINGS

Pharmacological and biological interventions are available for lowering Lp(a). However, the acceptability and feasibility of these approaches are questionable due to cost and lack of clinical evidence for their efficacy. A number of low-cost, minimal patient contact interventions are available for modifying behavioural risk-factors that are associated with increased risk of ASCVD familial hypercholesterolaemia and diabetes. These include lifestyle interventions designed to improve diet and physical activity. These interventions may be particularly important among individuals with elevated Lp(a) to manage their higher risk of diabetes and ASCVD. The following article outlines recent research that has examined such low-cost, minimal patient contact interventions.

SUMMARY

The current research indicated that such interventions, which are grounded in psychological theory, can assist individuals to improve their diet and physical activity. These findings have implications for developing and implementing similar interventions for individuals with elevated Lp(a), so as to assist in reducing behavioural risk-factors associated with ASCVD.

Long term follow-up of children with familial hypercholesterolemia and relatively normal LDL-cholesterol at diagnosis

Familial hypercholesterolemia (FH) is a genetic disorder with high low-density lipoprotein cholesterol (LDL-C) levels and high risk of cardiovascular disease. The long-term importance of carrying an FH mutation despite having relatively normal LDL-C levels in childhood is not known. We investigated the development of LDL-C levels and need of statin therapy in children with an FH mutation, with pretreatment LDL-C ≤ 4.1 mmol/L (~160 mg/dL), followed-up at lipid clinics in Oslo, Norway and Rotterdam, The Netherlands. Of 742 FH children, 109 (15%) had pretreatment LDL-C ≤ 4.1 mmol/L (~160 mg/dL) [mean (SD) 3.5 (0.5) mmol/L; (~130 (19) mg/dL)] measured at 11.8 (3.9) years of age [mean age (SD)]. After 8.2 (5.2) years [mean (SD)] of follow-up, 71.6% had started statin treatment. Therefore, all children carrying an FH mutation, independent of cholesterol levels, should receive follow-up at specialized lipid clinics for optimal and individualized treatment.

Reducing cardiovascular disease risk among families with familial hypercholesterolaemia by improving diet and physical activity: a randomised controlled feasibility trial

OBJECTIVE

Familial hypercholesterolaemia (FH) elevates low-density lipoprotein cholesterol (LDL-C) and increases cardiovascular disease (CVD) risk. This study aimed to provide evidence for the feasibility of conducting a randomised controlled trial to evaluate the efficacy of an intervention designed to improve diet and physical activity in families with FH.

DESIGN

A parallel, randomised, waitlist-controlled, feasibility pilot trial.

SETTING

Three outpatient lipid clinics in the UK.

PARTICIPANTS

Families that comprised children (aged 10-18 years) and their parent with genetically diagnosed FH.

INTERVENTION

Families were randomised to either 12-week usual care or intervention. The behavioural change intervention aimed to improve dietary, physical activity and sedentary behaviours. It was delivered to families by dietitians initially via a single face-to-face session and then by four telephone or email follow-up sessions.

OUTCOME MEASURES

Feasibility was assessed via measures related to recruitment, retention and intervention fidelity. Postintervention qualitative interviews were conducted to explore intervention acceptability. Behavioural (dietary intake, physical activity and sedentary time) and clinical (blood pressure, body composition and blood lipids) outcomes were collected at baseline and endpoint assessments to evaluate the intervention's potential benefit.

RESULTS

Twenty-one families (38% of those approached) were recruited which comprised 22 children and 17 adults with FH, and 97% of families completed the study. The intervention was implemented with high fidelity and the qualitative data revealed it was well accepted. Between-group differences at the endpoint assessment were indicative of the intervention's potential for improving diet in children and adults. Evidence for potential benefits on physical activity and sedentary behaviours was less apparent. However, the intervention was associated with improvements in several CVD risk factors including LDL-C, with a within-group mean decrease of 8% (children) and 10% (adults).

CONCLUSIONS

The study's recruitment, retention, acceptability and potential efficacy support the development of a definitive trial, subject to identified refinements.

TRIAL REGISTRATION NUMBER

ISRCTN24880714.

Proprotein convertase subtilisin/kexin type 9 inhibitor utilization and low-density lipoprotein-cholesterol control in familial hypercholesterolemia

BACKGROUND

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors were approved in August 2015 as an adjunct to maximally tolerated statin treatment in those with familial hypercholesterolemia (FH).

OBJECTIVE

To assess PCSK9 inhibitor utilization patterns and cholesterol control in the high-risk FH population.

METHODS

This study was a retrospective analysis of a large administrative database that includes privately insured and Medicare Advantage patients. Individuals with diagnosis codes for FH from October 2016-September 2019 were identified. Differences in PCSK9 inhibitor utilization between various groups were evaluated using multivariable logistic regression.

RESULTS

During the study period, 1:371 people enrolled in medical/pharmacy plans had a diagnosis of FH. While 62.5% (n = 33,649) had medication fills for statins (without PCSK9 inhibitors), only 2.0% (n = 1062) had medication fills for PCSK9 inhibitors (with or without other medications). Compared to men, women were more likely to be untreated (OR 1.23, 95% confidence interval (CI):1.18-1.28, p < 0.01) but more likely to be treated with PCSK9 inhibitors (OR 2.18, 95%CI:1.90-2.49, p < 0.01). Compared to those younger than 55 years of age, older individuals were more likely to be treated (OR 1.64, 95%CI:1.56-1.72, p < 0.01) but less likely to be treated with PCSK9 inhibitors (OR 0.40, 95%CI:0.34-0.47, p < 0.01). Lastly, those with household incomes ≥$40,000 were more likely to be treated with PCSK9 inhibitors than those with lower household incomes (OR 1.69, 95%CI:1.41-2.02, p < 0.01).

CONCLUSION

PCSK9 inhibitor utilization in FH remains low. Significant differences exist based on demographic factors. Female sex, higher household incomes, and younger age were associated with increased PCSK9 inhibitor utilization.