The burden of severe hypercholesterolemia and familial hypercholesterolemia in a population-based setting in the US

Prevalence of Severe Hypercholesterolemia and Familial Hypercholesterolemia Phenotype in Patients with Acute Coronary Syndrome

Background and Objectives: Atherosclerotic cardiovascular disease is one of the most common causes of death and disability around the world. Hypercholesterolemia is an established and widely prevalent risk factor; however, the prevalence of severe hypercholesterolemia (which is characteristic for familial hypercholesterolemia) has been studied far less. The aim of this study was to determine the prevalence of severe hypercholesterolemia among patients with acute coronary syndrome. Materials and Methods: A retrospective study of patients hospitalised at Vilnius University Hospital Santaros Klinikos due to acute coronary syndrome was performed. Data were attained from an electronic medical history database. Data such as sex, age, cardiovascular risk factors (hypertension, diabetes) and low-density cholesterol results were collected. Severe hypercholesterolemia was defined as low-density lipoprotein cholesterol levels ≥ 4.9 mmol/L. Results: A total of 34,669 patients were included in this study (12,115 females (34.9%) and 22554 (65.1%) males, p < 0.001). The median age of the entire study population was 67 years. A total of 3434 patients (9.9%) had severe hypercholesterolemia, 371 (1.1%) patients met the criteria for phenotypically probable familial hypercholesterolemia, and 36 (0.1%) patients presented with phenotypically definite familial hypercholesterolemia. The most common concomitant risk factor in this study was arterial hypertension, which was found in 48% of patients. Conclusions: Based on the results of this study, severe hypercholesterolemia is prevalent among patients with acute coronary syndrome, with as many as 9.9% of patients presenting with severe hypercholesterolemia at the time of hospitalisation. The definite familial hypercholesterolemia phenotype is scarcer, with prevalence reaching 0.1% of patients with acute coronary syndrome.

Integrative analysis of miRNAs and proteins in plasma extracellular vesicles of patients with familial hypercholesterolemia

BACKGROUND AND AIMS

Familial Hypercholesterolemia (FH) is a monogenic disease that leads to early-onset atherosclerosis. Causative mutations in FH-related genes are found in 60-80 % of patients, while epigenetic factors may contribute to mutation-negative cases. This study analyzed miRNAs and proteins from plasma-derived extracellular vesicles (EVs) of FH patients to explore their contribution in FH diagnosis.

METHODS

Clinical and laboratory data were obtained from 54 FH patients and 38 normolipidemic individuals. FH-related gene variants were identified using exon-targeted gene sequencing. Plasma EVs miRNome and proteome were analysed using small RNA sequencing and liquid chromatography/mass spectrometry.

RESULTS

Thirteen FH patients carried LDLR deleterious variants (MD group), while 41 did not (non-MD group). Over 2000 miRNAs were detected in plasma EVs, with miR-122-5p higher in FH patients compared to controls, and miR-21-5p higher in the MD group than in the non-MD group (p < 0.05). Proteomic analysis identified 300 proteins with 18 out of 38 proteins more abundant in EVs than in total plasma. Eighteen EVs-derived proteins had differential abundance in FH patients compared to control group (p < 0.05). EV levels of miR-122-5p, miR-21-5p and 12 proteins were correlated with serum lipids (p < 0.05). The integrative analysis between dysregulated miRNAs (miR-122-5p and miR-21-5p) and altered proteins (APOD, APOF, MBL2 and MASP1) from EVs identified several common pathways involved in cholesterol metabolism.

CONCLUSION

Co-regulation of plasma EVs miR-122-5p, miR-21-5p, APOD, APOF, MBL2 and MASP1 and their correlation with serum lipids suggest their involvement in impaired cholesterol metabolism and may be useful as biomarkers of FH severity.

Early-onset atherosclerotic cardiovascular disease

Recent trends indicate a concerning increase in early-onset atherosclerotic cardiovascular disease (ASCVD) among younger individuals (men aged <55 years women aged <65 years). These findings highlight the pathobiology of ASCVD as a disease process that begins early in life and underscores the need for more tailored screening methods and preventive strategies. Increasing attention has been placed on the growing burden of traditional cardiometabolic risk factors in young individuals while also recognizing unique factors that mediate risk of pre-mature atherosclerosis in this demographic such as substance use, socioeconomic disparities, adverse pregnancy outcomes, and chronic inflammatory states that contribute to the increasing incidence of early ASCVD. Additionally, mounting evidence has pointed out significant disparities in the diagnosis and management of early ASCVD and cardiovascular outcomes based on sex and race. Moving towards a more personalized approach, emerging data and technological developments using diverse tools such as polygenic risk scores and coronary artery calcium scans have shown potential in earlier detection of ASCVD risk. Thus, we review current evidence on causal risk factors that drive the increase in early ASCVD and highlight emerging tools to improve ASCVD risk assessment in young individuals.

Subclinical Atherosclerosis to Guide Treatment in Dyslipidemia and Diabetes Mellitus

PURPOSE OF REVIEW

Dyslipidemia and type 2 diabetes mellitus are two common conditions that are associated with an increased risk of atherosclerotic cardiovascular disease (ASCVD). In this review, we aimed to provide an in-depth and contemporary review of non-invasive approaches to assess subclinical atherosclerotic burden, predict cardiovascular risk, and guide appropriate treatment strategies. We focused this paper on two main imaging modalities: coronary artery calcium (CAC) score and computed tomography coronary angiography.

RECENT FINDINGS

Recent longitudinal studies have provided stronger evidence on the relationship between increased CAC, thoracic aorta calcification, and risk of cardiovascular events among those with primary hypercholesterolemia, highlighting the beneficial role of statin therapy. Interestingly, resilient profiles of individuals not exhibiting atherosclerosis despite dyslipidemia have been described. Non-conventional markers of dyslipidemia have also been associated with increased subclinical atherosclerosis presence and burden, highlighting the contribution of apolipoprotein B-100 (apoB)-rich lipoprotein particles, such as remnant cholesterol and lipoprotein(a), to the residual risk of individuals on-target for low-density lipoprotein cholesterol (LDL-C) goals. Regarding type 2 diabetes mellitus, variability in atherosclerotic burden has also been found, and CAC testing has shown significant predictive value in stratifying cardiovascular risk. Non-invasive assessment of subclinical atherosclerosis can help reveal the continuum of ASCVD risk in those with dyslipidemia and diabetes mellitus and can inform personalized strategies for cardiovascular disease prevention in the primary prevention setting.

Impact of 12-SNP and 6-SNP Polygenic Scores on Predisposition to High LDL-Cholesterol Levels in Patients with Familial Hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia (FH) comprises high LDL-cholesterol (LDL-c) levels and high cardiovascular disease risk. In the absence of pathogenic variants in causative genes, a polygenic basis was hypothesized.

METHODS

In a population of 418 patients (excluding homozygotes) with clinical suspicion of FH, the FH-causative genes and the regions of single nucleotide polymorphisms (SNPs) included in 12-SNP and 6-SNP scores were sequenced by next-generation sequencing, allowing for the detection of pathogenic variants (V+) in 220 patients. To make a comparison, only patients without uncertain significance variants (V-/USV-) were considered (n = 162).

RESULTS

Higher values of both scores were observed in V+ than in V-. Considering a cut-off leading to 80% of V-/USV- as score-positive, a lower prevalence of patients positive for both 12-SNP and 6-SNP scores was observed in V+ (p = 0.010 and 0.033, respectively). Mainly for the 12-SNP score, among V+ patients, higher LDL-c levels were observed in score-positive (223 mg/dL -IQR 187-279) than in negative patients (212 mg/dL -IQR 162-240; p = 0.006). Multivariate analysis confirmed the association of scores and LDL-c levels independently of age, sex, and presence of pathogenic variants and revealed a greater association in children.

CONCLUSIONS

The 12-SNP and 6-SNP polygenic scores could explain hypercholesterolemia in patients without pathogenic variants as well as the variability of LDL-c levels among patients with FH-causative variants.

Sex Differences in Diagnosis, Treatment, and Cardiovascular Outcomes in Homozygous Familial Hypercholesterolemia

Importance

Homozygous familial hypercholesterolemia (HoFH) is a rare genetic condition characterized by extremely increased low-density lipoprotein (LDL) cholesterol levels and premature atherosclerotic cardiovascular disease (ASCVD). Heterozygous familial hypercholesterolemia (HeFH) is more common than HoFH, and women with HeFH are diagnosed later and undertreated compared to men; it is unknown whether these sex differences also apply to HoFH.

Objective

To investigate sex differences in age at diagnosis, risk factors, lipid-lowering treatment, and ASCVD morbidity and mortality in patients with HoFH.

Design, Setting, and Participants

Sex-specific analyses for this retrospective cohort study were performed using data from the HoFH International Clinical Collaborators (HICC) registry, the largest global dataset of patients with HoFH, spanning 88 institutions across 38 countries. Patients with HoFH who were alive during or after 2010 were eligible for inclusion. Data entry occurred between February 2016 and December 2020. Data were analyzed from June 2022 to June 2023.

Main Outcomes and Measures

Comparison between women and men with HoFH regarding age at diagnosis, presence of risk factors, lipid-lowering treatment, prevalence, and onset and incidence of ASCVD morbidity (myocardial infarction [MI], aortic stenosis, and combined ASCVD outcomes) and mortality.

Results

Data from 389 women and 362 men with HoFH from 38 countries were included. Women and men had similar age at diagnosis (median [IQR], 13 [6-26] years vs 11 [5-27] years, respectively), untreated LDL cholesterol levels (mean [SD], 579 [203] vs 596 [186] mg/dL, respectively), and cardiovascular risk factor prevalence, except smoking (38 of 266 women [14.3%] vs 59 of 217 men [27.2%], respectively). Prevalence of MI was lower in women (31 of 389 [8.0%]) than men (59 of 362 [16.3%]), but age at first MI was similar (mean [SD], 39 [13] years in women vs 38 [13] years in men). Treated LDL cholesterol levels and lipid-lowering therapy were similar in both sexes, in particular statins (248 of 276 women [89.9%] vs 235 of 258 men [91.1%]) and lipoprotein apheresis (115 of 317 women [36.3%] vs 118 of 304 men [38.8%]). Sixteen years after HoFH diagnosis, women had statistically significant lower cumulative incidence of MI (5.0% in women vs 13.7% in men; subdistribution hazard ratio [SHR], 0.37; 95% CI, 0.21-0.66) and nonsignificantly lower all-cause mortality (3.0% in women vs 4.1% in men; HR, 0.76; 95% CI, 0.40-1.45) and cardiovascular mortality (2.6% in women vs 4.1% in men; SHR, 0.87; 95% CI, 0.44-1.75).

Conclusions and Relevance

In this cohort study of individuals with known HoFH, MI was higher in men compared with women yet age at diagnosis and at first ASCVD event were similar. These findings suggest that early diagnosis and treatment are important in attenuating the excessive cardiovascular risk in both sexes.

Effect of clinical decision support for severe hypercholesterolemia on low-density lipoprotein cholesterol levels

Severe hypercholesterolemia/possible familial hypercholesterolemia (FH) is relatively common but underdiagnosed and undertreated. We investigated whether implementing clinical decision support (CDS) was associated with lower low-density lipoprotein cholesterol (LDL-C) in patients with severe hypercholesterolemia/possible FH (LDL-C ≥ 190 mg/dL). As part of a pre-post implementation study, a CDS alert was deployed in the electronic health record (EHR) in a large health system comprising 3 main sites, 16 hospitals and 53 clinics. Data were collected for 3 months before ('silent mode') and after ('active mode') its implementation. Clinicians were only able to view the alert in the EHR during active mode. We matched individuals 1:1 in both modes, based on age, sex, and baseline lipid lowering therapy (LLT). The primary outcome was difference in LDL-C between the two groups and the secondary outcome was initiation/intensification of LLT after alert trigger. We identified 800 matched patients in each mode (mean ± SD age 56.1 ± 11.8 y vs. 55.9 ± 11.8 y; 36.0% male in both groups; mean ± SD initial LDL-C 211.3 ± 27.4 mg/dL vs. 209.8 ± 23.9 mg/dL; 11.2% on LLT at baseline in each group). LDL-C levels were 6.6 mg/dL lower (95% CI, -10.7 to -2.5; P = 0.002) in active vs. silent mode. The odds of high-intensity statin use (OR, 1.78; 95% CI, 1.41-2.23; P < 0.001) and LLT initiation/intensification (OR, 1.30, 95% CI, 1.06-1.58, P = 0.01) were higher in active vs. silent mode. Implementation of a CDS was associated with lowering of LDL-C levels in patients with severe hypercholesterolemia/possible FH, likely due to higher rates of clinician led LLT initiation/intensification.

Trends of Lipid Concentrations, Awareness, Evaluation, and Treatment in Severe Dyslipidemia in US Adults

OBJECTIVE

To evaluate the contemporary trends of lipid concentrations, cholesterol evaluation, hypercholesterolemia awareness, and statin use among individuals with severe dyslipidemia (low-density lipoprotein cholesterol [LDL-C] level ≥190 mg/dL) between 2011 and 2020.

PATIENTS AND METHODS

This serial cross-sectional analysis included nonpregnant adults ≥20 years of age from the National Health and Nutrition Examination Survey between 2011 and 2020. Age-adjusted weighted trends of LDL-C, triglycerides, cholesterol evaluation in the past 5 years, hypercholesterolemia awareness, and documented statin use among individuals with severe dyslipidemia were estimated.

RESULTS

Among 24,722 participants included, the prevalence of severe dyslipidemia was 5.4% (SE: 0.2%) which was stable across the study period (Ptrend=.78). Among individuals with severe dyslipidemia (mean age: 55.3 [SE: 0.7] years; 52.2% females; 68.8% non-Hispanic White), LDL-C (224.3 [SE: 4.2] mg/dL in 2011-2012 to 224.2 [SE: 4.6] mg/dL in 2017-2020; Ptrend =.83), and triglyceride (123.3 [SE: 1.1] mg/dL in 2011-2012 to 101.8 [SE: 1.1] mg/dL in 2017-2020; Ptrend=.13), levels remained stable from 2011 to 2020. The rates of cholesterol evaluation in the past 5 years (72.0% [SE: 5.7%] in 2011-2012 to 78.0% [SE: 4.8%] in 2017-2020; Ptrend=.91), hypercholesterolemia awareness (48.1% [SE: 5.5%] in 2011-2012 to 51.9% [SE: 5.8%] in 2017- 2020; Ptrend=.77), and documented statin use (34.7% [SE: 4.5%] in 2011-2012 to 33.4% [SE: 4.0%] in 2017-2020; Ptrend=.28) remained stagnant in individuals with severe dyslipidemia between 2011 and 2020.

CONCLUSION

Among individuals with severe dyslipidemia, cholesterol evaluation and hypercholesterolemia awareness rates were stable at ∼75% and ∼50% in the past decade. Only ∼34% of individuals with severe dyslipidemia took statins between 2011 and 2020, which likely contributed to the stable LDL-C levels noted across the study period. Further investigations into the determinants of statin use and adherence to statins are needed.

Longitudinal Trends in Severe Dyslipidemia in the Czech Population: The Czech MONICA and Czech Post-MONICA Study

Background: Severe hypercholesterolemia is associated with an increase in the risk of developing atherosclerotic cardiovascular disease. The aim of this analysis was to assess longitudinal trends in severe dyslipidemia (defined as total cholesterol > 8 mmol/L or LDL-cholesterol > 5 mmol/L) in a representative population sample of the Czech Republic and to analyze the longitudinal trends in the basic characteristics of individuals with severe dyslipidemia. Methods: Seven independent cross-sectional surveys were organized in the Czech Republic to screen for major cardiovascular risk factors (from 1985 to 2015-2018). A total of 20,443 randomly selected individuals aged 25-64 years were examined. Results: The overall prevalence of severe dyslipidemia was 6.6%, with a significant downward trend from the fifth survey onwards (2000/2001). Over the study period of 30+ years, the individuals with severe dyslipidemia became older, increased in BMI, and did not change their smoking habits. Total cholesterol and non-HDL-cholesterol decreased significantly in both sexes throughout the duration of the study. Conclusions: Despite a significant improvement in lipids in the Czech Republic from 1985, substantially contributing to the decline in cardiovascular mortality, the number of individuals with severe dyslipidemia remained high, and in most cases, they were newly detected during our screening examinations and were thus untreated.

Attainment of the low-density lipoprotein cholesterol treatment target and prognosis of heterozygous familial hypercholesterolemia

BACKGROUND AND AIMS

No previous study has investigated the association between attainment of low-density lipoprotein (LDL) cholesterol treatment target and better prognosis in patients with familial hypercholesterolemia (FH). The current research aimed to examine the association between attainment of LDL cholesterol treatment target and major adverse cardiac events (MACEs) in patients with FH to validate the current LDL cholesterol treatment targets in primary (<100 mg/dL) and secondary (<70 mg/dL) prevention settings.

METHODS

The data of patients with FH who were admitted to Kanazawa University Hospital between 2000 and 2020 and who were followed-up were retrospectively reviewed. The number of MACEs, including mortality associated with cardiovascular disease, unstable angina, and myocardial infarction per 1000 person-years, was calculated for each stratum for the attainment of LDL cholesterol target.

RESULTS

The median follow-up duration was 12.6 years. In total, 132 MACEs were recorded during the follow-up period. The numbers of patients who attained the LDL cholesterol target in the primary and secondary prevention groups were 228 (31.9%) and 40 (11.9%), respectively. The event rates per 1000 person-years for LDL cholesterol levels of <100 and ≥100 mg/dL in the primary prevention group were 2.6 and 4.4, respectively. The event rates per 1000 person-years for LDL cholesterol levels of <70 and ≥70 mg/dL in the secondary prevention group were 15.3 and 27.5, respectively.

CONCLUSIONS

Attainment of the LDL cholesterol target is associated with better prognosis in patients with FH. However, the attainment rate is currently inadequate among Japanese.

Familial Hypercholesterolemia and Its Current Diagnostics and Treatment Possibilities: A Literature Analysis

Familial hypercholesterolemia (FH) is a common, inherited disorder of cholesterol metabolism. This pathology is usually an autosomal dominant disorder and is caused by inherited mutations in the APOB, LDLR, and PCSK9 genes. Patients can have a homozygous or a heterozygous genotype, which determines the severity of the disease and the onset age of cardiovascular disease (CVD) manifestations. The incidence of heterozygous FH is 1: 200-250, whereas that of homozygous FH is 1: 100.000-160.000. Unfortunately, FH is often diagnosed too late and after the occurrence of a major coronary event. FH may be suspected in patients with elevated blood low-density lipoprotein cholesterol (LDL-C) levels. Moreover, there are other criteria that help to diagnose FH. For instance, the Dutch Lipid Clinical Criteria are a helpful diagnostic tool that is used to diagnose FH. FH often leads to the development of early cardiovascular disease and increases the risk of sudden cardiac death. Therefore, early diagnosis and treatment of this disease is very important. Statins, ezetimibe, bile acid sequestrants, niacin, PCSK9 inhibitors (evolocumab and alirocumab), small-interfering-RNA-based therapeutics (inclisiran), lomitapide, mipomersen, and LDL apheresis are several of the available treatment possibilities that lower LDL-C levels. It is important to say that the timeous lowering of LDL-C levels can reduce the risk of cardiovascular events and mortality in patients with FH. Therefore, it is essential to increase awareness of FH in order to reduce the burden of acute coronary syndrome (ACS).