Elevated lipoprotein(a), hypertension and renal insufficiency as predictors of coronary artery disease in patients with genetically confirmed heterozygous familial hypercholesterolemia

Coronary artery event-free or resilient familial hypercholesterolemia: what's in a name?

PURPOSE OF REVIEW

Familial hypercholesterolemia (FH) is an autosomal semi-dominant condition, characterized by excessive circulating low-density lipoprotein cholesterol (LDL-C) from birth that substantially accelerates the onset and progression of atherosclerotic cardiovascular disease (ASCVD), classically coronary artery disease (CAD). Elevated plasma LDL-C integrated over time is unequivocally the major determinant of ASCVD in heterozygous FH (HeFH); however, the wide variation in incidence and progression of ASCVD suggests a role for a wide spectrum of risk modifiers. We reviewed recent evidence describing the features of an ASCVD-free entity referred to as resilient FH among patients with HeFH.

RECENT FINDINGS

Compared with nonresilient FH patients, resilient patients are more likely to be female, and have a lower prevalence of ASCVD comorbidities, higher levels of HDL-C and larger HDL particles, as well as a lower level of lipoprotein(a). A lower SAFEHEART risk score is also an independent predictor of resilient FH. Gene expression studies also demonstrate that resilient FH patients are associated with a less atherogenic gene expression profile in relation to HDL metabolism and immune responses, as reflected by higher expression of ABCA1 and ABCG1, and lower expression of STAT2 and STAT3, respectively.

SUMMARY

A group of HeFH patients, referred as resilient FH, can survive to advance ages without experiencing any ASCVD events. Several key contributors to the event-fee CAD in HeFH patients have been identified. This could not only improve risk stratification and management for FH but also be of major importance for the general population in primary and secondary prevention. However, resilient FH remains an under-investigated area and requires further research.

Clinical practice recommendations on lipoprotein apheresis for children with homozygous familial hypercholesterolaemia: An expert consensus statement from ERKNet and ESPN

Homozygous familial hypercholesterolaemia is a life-threatening genetic condition, which causes extremely elevated LDL-C levels and atherosclerotic cardiovascular disease very early in life. It is vital to start effective lipid-lowering treatment from diagnosis onwards. Even with dietary and current multimodal pharmaceutical lipid-lowering therapies, LDL-C treatment goals cannot be achieved in many children. Lipoprotein apheresis is an extracorporeal lipid-lowering treatment, which is used for decades, lowering serum LDL-C levels by more than 70% directly after the treatment. Data on the use of lipoprotein apheresis in children with homozygous familial hypercholesterolaemia mainly consists of case-reports and case-series, precluding strong evidence-based guidelines. We present a consensus statement on lipoprotein apheresis in children based on the current available evidence and opinions from experts in lipoprotein apheresis from over the world. It comprises practical statements regarding the indication, methods, treatment goals and follow-up of lipoprotein apheresis in children with homozygous familial hypercholesterolaemia and on the role of lipoprotein(a) and liver transplantation.

Familial hypercholesterolemia

Familial hypercholesterolemia is a common genetic disorder of autosomal inheritance associated with elevated LDL-cholesterol. It is estimated to affect 1:250 individuals in general population roughly estimated to be 5 million in India. The prevalence of FH is higher in young CAD patients (<55 years in men; <60 years in women). FH is underdiagnosed and undertreated. Screening during childhood and Cascade screening of family members of known FH patients is of utmost importance in order to prevent the burden of CAD. Early identification of FH patients and early initiation of the lifelong lipid lowering therapy is the most effective strategy for managing FH. FH management includes pharmaceutical agents (statins and non statin drugs) and lifestyle modification. Inspite of maximum dose of statin with or without Ezetimibe, if target levels of LDL-C are not achieved, Bempedoic acid, proprotein convertase subtilisin/kexin type 9 (PCSK9) Inhibitors/Inclisiran can be added.

Clinical practice recommendations on lipoprotein apheresis for children with homozygous familial hypercholesterolemia: an expert consensus statement from ERKNet and ESPN

Homozygous familial hypercholesterolaemia is a life-threatening genetic condition, which causes extremely elevated LDL-C levels and atherosclerotic cardiovascular disease very early in life. It is vital to start effective lipid-lowering treatment from diagnosis onwards. Even with dietary and current multimodal pharmaceutical lipid-lowering therapies, LDL-C treatment goals cannot be achieved in many children. Lipoprotein apheresis is an extracorporeal lipid-lowering treatment, which is well established since three decades, lowering serum LDL-C levels by more than 70% per session. Data on the use of lipoprotein apheresis in children with homozygous familial hypercholesterolaemia mainly consists of case-reports and case-series, precluding strong evidence-based guidelines. We present a consensus statement on lipoprotein apheresis in children based on the current available evidence and opinions from experts in lipoprotein apheresis from over the world. It comprises practical statements regarding the indication, methods, treatment targets and follow-up of lipoprotein apheresis in children with homozygous familial hypercholesterolaemia and on the role of lipoprotein(a) and liver transplantation.

Effect of Omega-3 Fatty Acid Supplementation on the Postprandial Metabolism of Apolipoprotein(a) in Familial Hypercholesterolemia

AIM

Lipoprotein(a) (Lp(a)) is a low-density lipoprotein-like particle containing apolipoprotein(a) (apo(a)) that increases the risk of atherosclerotic cardiovascular disease (ASCVD) in familial hypercholesterolemia (FH). Postprandial redistribution of apo(a) protein from Lp(a) to triglyceride-rich lipoproteins (TRLs) may also increase the atherogenicity of TRL particles. Omega-3 fatty acid (ω3FA) supplementation improves postprandial TRL metabolism in FH subjects. However, its effect on postprandial apo(a) metabolism has yet to be investigated.

METHODS

We carried out an 8-week open-label, randomized, crossover trial to test the effect of ω3FA supplementation (4 g/day) on postprandial apo(a) responses in FH patients following ingestion of an oral fat load. Postprandial plasma total and TRL-apo(a) concentrations were measured by liquid chromatography with tandem mass spectrometry, and the corresponding areas under the curve (AUCs) (0-10h) were determined using the trapezium rule.

RESULTS

Compared with no ω3FA treatment, ω3FA supplementation significantly lowered the concentrations of postprandial TRL-apo(a) at 0.5 (-17.9%), 1 (-18.7%), 2 (-32.6%), and 3 h (-19.2%) (P＜0.05 for all). Postprandial TRL-apo(a) AUC was significantly reduced with ω3FA by 14.8% (P＜0.05). By contrast, ω3FA had no significant effect on the total AUCs of apo(a), apoC-III, and apoE (P＞0.05 for all). The decrease in postprandial TRL-apo(a) AUC was significantly associated with changes in the AUC of triglycerides (r=0.600; P＜0.01) and apoB-48 (r=0.616; P＜0.01).

CONCLUSIONS

Supplementation with ω3FA reduces postprandial TRL-apo(a) response to a fat meal in FH patients; this novel metabolic effect of ω3FA may have implications on decreasing the risk of ASCVD in patients with FH, especially in those with elevated plasma triglyceride and Lp(a) concentrations. However, the clinical implications of these metabolic findings require further evaluation in outcome or surrogate endpoint trials.

Hepatic fat as a novel marker for high-risk coronary atherosclerotic plaque features in familial hypercholesterolaemia

BACKGROUND & AIMS

Hepatic steatosis has been associated with increased risk of coronary artery disease. Individuals with familial hypercholesterolaemia have accelerated but variable progression of coronary artery disease. We investigated whether hepatic steatosis is associated with novel coronary atherosclerosis biomarkers in adults with heterozygous familial hypercholesterolaemia, using comprehensive coronary computed tomographic angiography.

METHODS

We conducted a cross-sectional study of 213 asymptomatic patients with familial hypercholesterolaemia (median age 54.0 years, 59 % female) who underwent coronary computed tomographic angiography for cardiovascular risk assessment in an outpatient clinic. High-risk plaque features, plaque volume and pericoronary adipose tissue attenuation were assessed. From concurrently captured upper abdominal images, severity of hepatic steatosis was computed, as liver minus spleen computed tomography attenuation and stratified into quartiles.

RESULTS

Of 213 familial hypercholesterolaemia patients, 59 % had coronary artery calcium, 36 % obstructive coronary artery disease (≥50 % stenosis) and 77 % high-risk plaque features. Increasing hepatic steatosis was associated with higher calcium scores, more high-risk plaque features and presence of obstructive coronary artery disease. Hepatic steatosis was associated with the presence of high-risk plaque features (OR: 1.48; 95 % CI: 1.09-2.00; p = 0.01), particularly in the proximal coronary segments (OR: 1.52; 95 % CI: 1.18-1.96; p = 0.001). Associations persisted on multivariable logistic regression analysis adjusting for cardiometabolic factors, obstructive coronary artery disease and calcium score. Hepatic steatosis was associated with higher plaque volumes (Q4: 499 mm³ vs Q1: 414 mm³, p = 0.02), involving mainly low attenuation and noncalcified plaques (both p = 0.03). No differences in pericoronary adipose tissue attenuation were observed.

CONCLUSIONS

Hepatic steatosis is associated with multiple indices of advanced coronary atherosclerosis in familial hypercholesterolaemia patients, particularly high-risk plaque features, independent of conventional cardiovascular risk factors and markers. This may involve specific mechanisms related to hepatic steatosis.

CLINICAL TRIAL NUMBER

N/A.

Prevalence of Diabetes and Its Association with Atherosclerotic Cardiovascular Disease Risk in Patients with Familial Hypercholesterolemia: An Analysis from the Hellenic Familial Hypercholesterolemia Registry (HELLAS-FH)

Familial hypercholesterolemia (FH) and type 2 diabetes mellitus (T2DM) are both associated with a high risk of atherosclerotic cardiovascular disease (ASCVD). Little is known about the prevalence of T2DM and its association with ASCVD risk in FH patients. This was a cross-sectional analysis from the Hellenic Familial Hypercholesterolemia Registry (HELLAS-FH) including adults with FH (n = 1719, mean age 51.3 ± 14.6 years). Of FH patients, 7.2% had a diagnosis of T2DM. The prevalence of ASCVD, coronary artery disease (CAD), and stroke was higher among subjects with T2DM compared with those without (55.3% vs. 23.3%, 48.8% vs. 20.7%, 8.3% vs. 2.7%, respectively, p < 0.001). When adjusted for age, systolic blood pressure, smoking, body mass index, hypertension, waist circumference, triglyceride levels, high-density lipoprotein cholesterol levels, and gender, T2DM was significantly associated with prevalent ASCVD [OR 2.0 (95% CI 1.2−3.3), p = 0.004]. FH patients with T2DM were more likely to have undergone coronary revascularization than those without (14.2% vs. 4.5% for coronary artery bypass graft, and 23.9% vs. 11.5% for percutaneous coronary intervention, p < 0.001). T2DM is associated with an increased risk for prevalent ASCVD in subjects with FH. This may have implications for risk stratification and treatment intensity in these patients.

Cardiac markers: Role in the pathogenesis of arterial hypertension

Cardiac biomarkers may play unique roles in the prognostic evaluation of patients with hypertension, as many cardiac biomarker levels become abnormal long before the onset of obvious cardiovascular disease (CVD). There are numerous cardiac markers. However, this review article only reported the roles of creatinine kinase-MB, cardiac troponins, lipoprotein a, osteopontin, cardiac extracellular matrix, C-reactive protein, cardiac matrix metalloproteinases, cardiac natriuretic peptides, myoglobin, renin, and dynorphin in the pathogenesis of hypertension. This article explained recent major advances, as well as discoveries, significant gaps, and current debates and outlined possible directions for future research. Further studies are required to determine the association between myoglobin and other cardiac markers in hypertension. Moreover, therapeutic approaches are required to determine the early control of these cardiac markers, which ultimately reduce the prevalence of CVDs.

Clinical Aspects of Genetic and Non-Genetic Cardiovascular Risk Factors in Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is the most common monogenic metabolic disorder characterized by considerably elevated low-density lipoprotein cholesterol (LDL-C) levels leading to enhanced atherogenesis, early cardiovascular disease (CVD), and premature death. However, the wide phenotypic heterogeneity in FH makes the cardiovascular risk prediction challenging in clinical practice to determine optimal therapeutic strategy. Beyond the lifetime LDL-C vascular accumulation, other genetic and non-genetic risk factors might exacerbate CVD development. Besides the most frequent variants of three genes (LDL-R, APOB, and PCSK9) in some proband variants of other genes implicated in lipid metabolism and atherogenesis are responsible for FH phenotype. Furthermore, non-genetic factors, including traditional cardiovascular risk factors, metabolic and endocrine disorders might also worsen risk profile. Although some were extensively studied previously, others, such as common endocrine disorders including thyroid disorders or polycystic ovary syndrome are not widely evaluated in FH. In this review, we summarize the most important genetic and non-genetic factors that might affect the risk prediction and therapeutic strategy in FH through the eyes of clinicians focusing on disorders that might not be in the center of FH research. The review highlights the complexity of FH care and the need of an interdisciplinary attitude to find the best therapeutic approach in FH patients.

Diabetes and Familial Hypercholesterolemia: Interplay between Lipid and Glucose Metabolism

Familial hypercholesterolemia (FH) is a genetic disease characterized by high low-density lipoprotein (LDL) cholesterol (LDL-c) concentrations that increase cardiovascular risk and cause premature death. The most frequent cause of the disease is a mutation in the LDL receptor (LDLR) gene. Diabetes is also associated with an increased risk of cardiovascular disease and mortality. People with FH seem to be protected from developing diabetes, whereas cholesterol-lowering treatments such as statins are associated with an increased risk of the disease. One of the hypotheses to explain this is based on the toxicity of LDL particles on insulin-secreting pancreatic β-cells, and their uptake by the latter, mediated by the LDLR. A healthy lifestyle and a relatively low body mass index in people with FH have also been proposed as explanations. Its association with superimposed diabetes modifies the phenotype of FH, both regarding the lipid profile and cardiovascular risk. However, findings regarding the association and interplay between these two diseases are conflicting. The present review summarizes the existing evidence and discusses knowledge gaps on the matter.

Improving Familial Hypercholesterolemia Diagnosis Using an EMR-based Hybrid Diagnostic Model

CONTEXT

Familial hypercholesterolemia (FH) confers a greatly increased risk for premature cardiovascular disease, but remains very underdiagnosed and undertreated in primary care populations.

OBJECTIVE

We assessed whether using a hybrid model consisting of 2 existing FH diagnostic criteria coupled with electronic medical record (EMR) data would accurately identify patients with FH in a Midwest US metropolitan healthcare system.

METHODS

We conducted a retrospective, records-based, cross-sectional study using datasets from unique EMRs of living patients. Using Structured Query Language to identify components of 2 currently approved FH diagnostic criteria, we created a hybrid model to identify individuals with FH.

RESULTS

Of 264 264 records analyzed, between 794 and 1571 patients were identified as having FH based on the hybrid diagnostic model, with a prevalence of 1:300 to 1:160. These patients had a higher prevalence of premature coronary artery disease (CAD) (38-58%) than the general population (1.8%) and higher than those having a high CAD risk but no FH (10%). Although most patients were receiving lipid-lowering therapies (LLTs), only 50% were receiving guideline-recommended high-intensity LLT.

CONCLUSION

Using the hybrid model, we identified FH with a higher clinical and genetic detection rate than using standard diagnostic criteria individually. Statin and other LLT use were suboptimal and below guideline recommendations. Because FH underdiagnosis and undertreatment are due partially to the challenges of implementing existing diagnostic criteria in a primary care setting, this hybrid model potentially can improve FH diagnosis and subsequent early access to appropriate treatment.

Lipoprotein(a) as Part of the Diagnosis of Clinical Familial Hypercholesterolemia

PURPOSE OF REVIEW

Individuals with familial hypercholesterolemia have very high risk of cardiovascular disease due to lifelong elevations in LDL cholesterol. Elevated lipoprotein(a) is a risk factor for cardiovascular diseases such as myocardial infarction and aortic valve stenosis. It has been proposed to include elevated lipoprotein(a) in the diagnosis of clinical familial hypercholesterolemia.

RECENT FINDINGS

Lipoprotein(a) is co-measured in LDL cholesterol, and up to one-quarter of all diagnoses of clinical familial hypercholesterolemia are due to high levels of lipoprotein(a). Further, individuals with both familial hypercholesterolemia and elevated lipoprotein(a) have an extremely high risk of myocardial infarction. We discuss the background for familial hypercholesterolemia and elevated lipoprotein(a) as risk factors for cardiovascular disease and the consequences of the fact that LDL cholesterol measurements/calculations include the cholesterol present in lipoprotein(a). Finally, we discuss the potential of including lipoprotein(a) as part of the diagnosis of familial hypercholesterolemia and in consequence possible treatments.

Comorbidities with Familial Hypercholesterolemia (FH): A Systematic Review

Familial hypercholesterolemia (FH) is linked to high levels of low-density lipoprotein cholesterol (LDL-C), atherosclerotic, and aortic stenosis to a lesser extent. We looked at the incidence of prevalent comorbid disorders other than cardiovascular disease (CVD), such as diabetes, chronic kidney disease (CKD), hypertension, and cancer in heterozygous FH (HeFH) patients. PubMed, Web of Science, and Google Scholar were searched systematically for studies reporting comorbidities in FH patients. Finally, 23 studies were included after excluding duplicates, papers with unrelated titles, reviews, abstracts, and papers with not sufficient data. Results showed that among the comorbidities that have been studied; FH patients had a greater prevalence of CKD. In terms of diabetes, the data are inconsistent, with some research indicating a higher prevalence of diabetes in FH patients and mostly indicating the opposite. Polymorphism study showed that hypertension has been linked to FH; however, the prevalence of the hypertensive subjects varies among FH groups. In comparison to the general population, cancer was found to have a lower or similar prevalence in FH patients. More research is needed in this area due to the variability of the results of the relationship between diabetes and FH and the small number of studies on cancer. In conclusion only CKD can be considered as an important and prevalent comorbidity in FH population after CVDs.

Lipoprotein (a) and Hypertension

PURPOSE OF REVIEW

To provide an overview of the associations between elevated blood pressure and lipoprotein (a) and possible causal links, as well as data on the prevalence of elevated lipoprotein (a) in a cohort of hypertensive patients.

RECENT FINDINGS

Elevated lipoprotein (a) is now considered to be an independent and causal risk factor for atherosclerotic cardiovascular disease and calcific aortic valve disease. Despite this, there are limited data demonstrating an association between elevated lipoprotein (a) and hypertension. Further, there is limited mechanistic data linking lipoprotein (a) and hypertension through either renal impairment or direct effects on the vasculature. Despite the links between lipoprotein (a) and atherosclerosis, there are limited data demonstrating an association with hypertension. Evidence from our clinic suggests that ~ 30% of the patients in this at-risk, hypertensive cohort had elevated lipoprotein (a) levels and that measurement of lipoprotein (a) maybe useful in risk stratification.

Effectiveness of proprotein convertase subtilisin/kexin-9 monoclonal antibody treatment on plasma lipoprotein(a) concentrations in patients with elevated lipoprotein(a) attending a clinic

Background

Lipoprotein(a) (Lp[a]) is a causal risk factor for atherosclerotic cardiovascular disease (ASCVD). Proprotein convertase subtilisin/kexin‐9 monoclonal antibodies (PCSK9mAbs) can lower Lp(a) levels in clinical trials, but their effects in patients with elevated Lp(a) in clinical practice remain unclear.

Aims

To investigate the effectiveness and safety of PCSK9mAbs in lowering plasma Lp(a) in patients with elevated Lp(a) concentrations in a lipid clinic.

Methods

This was an open‐label study of 53 adult patients with elevated Lp(a) concentration (≥0.5 g/L). Clinical, biochemical, and safety data were collected before and on treatment with evolocumab or alirocumab over a mean period of 11 months.

Results

Treatment with a PCSK9mAb resulted in a significant reduction of 0.29 g/L (−22%) in plasma Lp(a) concentration (p<.001). There were also significant reductions in low‐density lipoprotein‐cholesterol (LDL‐C) (−53%), remnant‐cholesterol (−12%) and apolipoprotein B (−43%) concentrations. The change in Lp(a) concentration was significantly different from a comparable group of 35 patients with elevated Lp(a) who were not treated with a PCSK9mAb (−22% vs. −2%, p<.001). The reduction in Lp(a) concentration was not associated with the corresponding changes in LDL‐C, remnant‐cholesterol, and apolipoprotein B (p>.05 in all). 7.5% and 47% of the patients attained a target concentration of Lp(a) <0.5 g/L and LDL‐C <1.8 mmol/L, respectively. PCSK9mAbs were well tolerated, the common adverse effects being pharyngitis (9.4%), nasal congestion (7.6%), myalgia (9.4%), diarrhoea (7.6%), arthralgia (9.4%) and injection site reactions (11%).

Conclusion

PCSK9mAbs can effectively and safely lower plasma Lp(a) concentrations in patients with elevated Lp(a) in clinical practice; the impact of the fall in Lp(a) on ASCVD outcomes requires further investigation.

Lipoprotein metabolism in familial hypercholesterolemia

Familial hypercholesterolemia (FH) is one of the most common genetic disorders in humans. It is an extremely atherogenic metabolic disorder characterized by lifelong elevations of circulating LDL-C levels often leading to premature cardiovascular events. In this review, we discuss the clinical phenotypes of heterozygous and homozygous FH, the genetic variants in four genes (LDLR/APOB/PCSK9/LDLRAP1) underpinning the FH phenotype as well as the most recent in vitro experimental approaches used to investigate molecular defects affecting the LDL receptor pathway. In addition, we review perturbations in the metabolism of lipoproteins other than LDL in FH, with a major focus on lipoprotein (a). Finally, we discuss the mode of action and efficacy of many of the currently approved hypocholesterolemic agents used to treat patients with FH, with a special emphasis on the treatment of phenotypically more severe forms of FH.

The interconnection between lipoprotein(a), lipoprotein(a) cholesterol and true LDL-cholesterol in the diagnosis of familial hypercholesterolemia

PURPOSE OF REVIEW

Elevated levels of lipoprotein(a) [Lp(a)] are present in 30-50% of patients with familial hypercholesterolemia. The contribution of Lp(a) towards risk stratification of patients with familial hypercholesterolemia has been recently recognized, with studies showing a significantly worse prognosis if Lp(a) is elevated. However, the role of elevated Lp(a) in diagnosis of familial hypercholesterolemia is less well defined or accepted.

RECENT FINDINGS

An important confounder in the diagnosis of familial hypercholesterolemia is the significant contribution of the cholesterol content on Lp(a) (Lp(a)-C) in individuals with elevated Lp(a). Because Lp(a)-C is incorporated into all clinical LDL-C measurements, it can contribute significantly to the cholesterol threshold diagnostic criteria for familial hypercholesterolemia used in most clinical algorithms.

SUMMARY

In this review, we discuss the interrelationship of Lp(a), Lp(a)-C and correct LDL-C in the diagnosis and prognosis of familial hypercholesterolemia. Future studies of accurately measuring correct LDL-C or in using apoB-100 and Lp(a) criteria may overcome the limitations of using estimated LDL-C in the diagnosis of familial hypercholesterolemia in individuals with concomitant elevation of Lp(a).

Lipoprotein(a) in Patients With Type 2 Diabetes and Premature Coronary Artery Disease in the Coronary Care Unit

INTRODUCTION

Lipoprotein(a) [Lp(a)] and diabetes are independently associated with premature coronary artery disease (pCAD). However, there is an inverse relationship between Lp(a) concentration and type 2 diabetes (T2D) risk. We examine whether Lp(a) distribution in patients with pCAD differs between those with or without T2D, and whether elevated Lp(a) is associated with pCAD in patients with T2D.

METHODS

Lp(a) concentration was measured in consecutive acute coronary syndrome (ACS) patients in two coronary care units (study one: ACS with or without diabetes, study two: ACS and diabetes). Elevated Lp(a) mass concentration was defined as ≥0.5 g/L and pCAD where CAD was diagnosed age <60 years. The association between elevated Lp(a) and pCAD was assessed using logistic regression.

RESULTS

Of 449 patients, 233 (51.9%) had pCAD and 278 (61.9%) had T2D. In patients with pCAD, those with T2D had a significantly lower median Lp(a) concentration (0.13 g/L versus 0.27 g/L, p=0.004). In patients with T2D, elevated Lp(a) was significantly associated with pCAD (OR 2.419, 95% CI 1.513-3.867, p<0.001). After adjusting for gender, smoking, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides, elevated Lp(a) remained significantly associated with pCAD (OR 2.895, 95% CI 1.427-5.876, p=0.003) in patients with T2D.

CONCLUSIONS

In coronary care patients with pCAD, patients with T2D had lower Lp(a) concentrations than those without T2D. Despite this, elevated Lp(a) remained predictive of pCAD in patients with T2D. Measurement of Lp(a) should be considered in younger adults with T2D to identify who may benefit from earlier preventative therapies to reduce pCAD burden.

Lipoprotein(a) and Familial Hypercholesterolemia: A Short Review Including the Laboratory Viewpoint

Lipoprotein(a) (Lp(a)) and low-density lipoprotein cholesterol (LDL-C) are risk factors for cardiovascular disease (CVD). Individuals with familial hypercholesterolemia (FH) have a risk for CVD due to a high LDL-C value. Lp(a) also increases the CVD risk in FH individuals; thus, the Lp(a) value should be carefully managed. The LDL-C value may partly include Lp(a)-cholesterol (Lp(a)-C) in the measurement. Based on the LDL-C value, some individuals are likely misclassified as having FH and/or the status of treatment of FH can be monitored. The present review describes about Lp(a) in FH individuals in terms of the measurement issue of Lp(a) and the related management of FH.

The Knowns and Unknowns of Contemporary Statin Therapy for Familial Hypercholesterolemia

PURPOSE OF REVIEW

Statins are first-line therapy for lowering low-density lipoprotein (LDL) cholesterol in familial hypercholesterolemia (FH), particularly in heterozygous patients. We review advances and new questions on the use of statins in FH.

RECENT FINDINGS

Cumulative evidence from registry data and sub-analyses of clinical trials mandates the value of statin therapy for prevention of atherosclerotic cardiovascular disease (ASCVD) in FH. Statins are safe in children and adolescents with FH, with longer term cardiovascular benefits. The potentially toxic effects of statins in pregnancy need to be considered, but no association has been reported in prospective cohort studies with birth defects. There is no rationale for discontinuation of statins in elderly FH unless indicated by adverse events. FH is undertreated, with > 80% of statin-treated FH patients failing to attain LDL cholesterol treatment targets. This may relate to adherence, tolerability, and genetic differences in statin responsiveness. Statin treatment from childhood may reduce the need for stringent cholesterol targets. Combination of statins with ezetimibe and PCSK9 inhibitors significantly improves the efficacy of treatment. Whether statin use could improve the clinical course of FH patients with COVID-19 and other respiratory infections remains an unsolved issue for future research. Statins are the mainstay for primary and secondary prevention of ASCVD in FH. Sustained long-term optimal statin treatment from an early age can effectively prevent ASCVD over decades of life. Despite their widespread use, statins merit further investigation in FH.

Gaps in the Care of Familial Hypercholesterolaemia in Australia: First Report From the National Registry

BACKGROUND

Familial hypercholesterolaemia (FH) is under-diagnosed and under-treated worldwide, including Australia. National registries play a key role in identifying patients with FH, understanding gaps in care and advancing the science of FH to improve care for these patients.

METHODS

The FH Australasia Network has established a national web-based registry to raise awareness of the condition, facilitate service planning and inform best practice and care services in Australia. We conducted a cross-sectional analysis of 1,528 FH adults enrolled in the registry from 28 lipid clinics.

RESULTS

The mean age at enrolment was 53.4±15.1 years, 50.5% were male and 54.3% had undergone FH genetic testing, of which 61.8% had a pathogenic FH-causing gene variant. Only 14.0% of the cohort were family members identified through cascade testing. Coronary artery disease (CAD) was reported in 28.0% of patients (age of onset 49.0±10.5 years) and 64.9% had at least one modifiable cardiovascular risk factor. The mean untreated LDL-cholesterol was 7.4±2.5 mmol/L. 80.8% of patients were on lipid-lowering therapy with a mean treated LDL-cholesterol of 3.3±1.7 mmol/L. Among patients receiving lipid-lowering therapies, 25.6% achieved an LDL-cholesterol target of <2.5 mmol/L without CAD or <1.8 mmol/L with CAD.

CONCLUSION

Patients in the national FH registry are detected later in life, have a high burden of CAD and risk factors, and do not achieve guideline-recommended LDL-cholesterol targets. Genetic and cascade testing are under-utilised. These deficiencies in care need to be addressed as a public health priority.

Risk of cardiovascular disease with lipoprotein(a) in familial hypercholesterolemia: a review

Introduction

Lipoprotein(a) (Lp[a]) is a risk factor of cardiovascular disease (CVD). Familial hypercholesterolemia (FH), which exhibits high low-density lipoprotein cholesterol (LDL-C) levels, is a risk factor of CVD. The relationship of Lp(a) with CVD has been characterized in populations specific to FH.

Material and methods

Studies reporting on the relationship of Lp(a) with CVD among FH subjects via PubMed up to 2020 were reviewed.

Results

Eight studies were identified as eligible. In the meta-analyses, a high Lp(a) level was significantly and predictively associated with CVD compared to a low Lp(a) level in 2 cross-sectional studies (odds ratio = 2.57; 95% confidence interval (CI): 1.16–5.73) and 6 cohort studies (risk/hazard ratio = 1.91; 95% CI: 1.50–2.43). The totally integrated relative risk of these studies was 1.97 (95% CI: 1.57–2.46).

Conclusions

FH subjects with high Lp(a) levels can have a high CVD risk, and besides LDL-C, attention should be paid to Lp(a) levels in FH subjects.

A potent risk model for predicting new-onset acute coronary syndrome in patients with type 2 diabetes mellitus in Northwest China

AIMS

Type 2 diabetes mellitus (T2DM) is now very prevalent in China. Due to the lower rate of controlled diabetes in China compared to that in developed countries, there is a higher incidence of serious cardiovascular complications, especially acute coronary syndrome (ACS). The aim of this study was to establish a potent risk predictive model in the economically disadvantaged northwest region of China, which could predict the probability of new-onset ACS in patients with T2DM.

METHODS

Of 456 patients with T2DM admitted to the First Affiliated Hospital of Xi'an Jiaotong University from January 2018 to January 2019 and included in this study, 270 had no ACS, while 186 had newly diagnosed ACS. Overall, 32 demographic characteristics and serum biomarkers of the study patients were analysed. The least absolute shrinkage and selection operator regression was used to select variables, while the multivariate logistic regression was used to establish the predictive model that was presented using a nomogram. The area under the receiver operating characteristics curve (AUC) was used to evaluate the discriminatory capacity of the model. A calibration plot and Hosmer-Lemeshow test were used for the calibration of the predictive model, while the decision curve analysis (DCA) was used to evaluate its clinical validity.

RESULTS

After random sampling, 319 and 137 T2DM patients were included in the training and validation sets, respectively. The predictive model included age, body mass index, diabetes duration, systolic blood pressure (SBP), diastolic blood pressure (DBP), low-density lipoprotein cholesterol, serum uric acid, lipoprotein(a), hypertension history and alcohol drinking status as predictors. The AUC of the predictive model and that of the internal validation set was 0.830 [95% confidence interval (CI) 0.786-0.874] and 0.827 (95% CI 0.756-0.899), respectively. The predictive model showed very good fitting degree, and DCA demonstrated a clinically effective predictive model.

CONCLUSIONS

A potent risk predictive model was established, which is of great value for the secondary prevention of diabetes. Weight loss, lowering of SBP and blood uric acid levels and appropriate control for DBP may significantly reduce the risk of new-onset ACS in T2DM patients in Northwest China.

The Prevalence of Elevated Lipoprotein(a) in Patients Presenting With Coronary Artery Disease

BACKGROUND

Elevated lipoprotein(a) (Lp(a)) is an inherited lipid disorder and an independent risk factor for cardiovascular (CV) disease. Although its prevalence in the general population has been well-documented, the prevalence of elevated Lp(a) in patients with clinical coronary artery disease (CAD) is less clear. In this study, we hypothesised that there is an over-representation of elevated Lp(a) in patients with early-onset CAD compared to the general population.

METHODS

Between 6 February and 8 June 2018, we screened consecutive patients aged ≤70 years who presented to the Austin Hospital with any of the following criteria: (1) acute coronary syndrome (ACS); (2) percutaneous coronary intervention (PCI); or (3) coronary artery bypass grafting (CABG). Whilst examining a range of different Lp(a) levels, a dichotomous elevated Lp(a) was defined as concentrations ≥0.5 g/L. Other CV risk factors were documented including hypertension, type 2 diabetes mellitus, and familial hypercholesterolaemia (FH) using the Dutch Lipid Clinic Network Criteria (DLCNC), also incorporating family history and clinical examination.

RESULTS

One hundred and fifty-eight (158) patients were screened; 63 (39.9%) were under 60 years of age. Overall, elevated Lp(a) ≥0.5 g/L was identified in 57 patients (36.1%). Of these, nine patients (15.8%) also had probable or definite FH. General population data was obtained from the Copenhagen General Population Study which studied 6,000 men and women and showed that the estimated prevalence of Lp(a) ≥0.5 g/L in the general population was 20%.

CONCLUSIONS

Elevated Lp(a) is more prevalent in patients with relatively early-onset CAD compared to the general population and may contribute to previously unappreciated residual cardiovascular risk. Patients who present with early-onset CAD, should be routinely screened for elevated Lp(a).

Why patients with familial hypercholesterolemia are at high cardiovascular risk? Beyond LDL-C levels

Familial hypercholesterolemia (FH) is a common genetic cause of elevated low-density lipoprotein cholesterol (LDL-C) due to defective clearance of circulating LDL particles. All FH patients are at high risk for premature cardiovascular disease (CVD) events due to their genetically determined lifelong exposure to high LDL-C levels. However, different rates of CVD events have been reported in FH patients, even among those with the same genetic mutations and comparable LDL-C levels. Hence, additional CVD risk modifiers, beyond LDL-C, may contribute to increase CVD risk in the FH population. In this review, we discuss the overall CVD risk burden of the FH population. Additionally, we revise the prognostic impact of several traditional and emerging predictors of CVD risk and we provide an overview of the role of specific tools to stratify CVD risk in FH patients in order to ensure them a more personalized treatment approach.

An age-matched computed tomography angiographic study of coronary atherosclerotic plaques in patients with familial hypercholesterolaemia

BACKGROUND AND AIMS

Familial hypercholesterolaemia (FH) is characterised by a high, but variable risk of premature coronary artery disease (CAD). Cardiac computed tomography angiography (CCTA) can be employed to assess subclinical coronary atherosclerosis. We investigated the features and distribution of coronary artery plaques in asymptomatic patients with and without genetically confirmed heterozygous FH.

METHODS

We undertook an aged-matched case-control study of asymptomatic phenotypic FH patients with (cases, M+) and without (controls, M-) an FH-causing mutation. Coronary atherosclerosis was assessed by CCTA and calcium scoring. Coronary segments were evaluated for global and vessel-level coronary plaques and degree of stenosis.

RESULTS

We studied 104 cases and 104 controls (mean age 49.9 ± 10.4 years), who had a similar spectrum of non-cardiovascular risk factors. Pre-treatment plasma LDL-cholesterol was higher in the M+ than M- group (7.8 ± 2.1 vs 6.2 ± 1.2 mmol/L, p<0.001). There was a greater proportion of patients with mixed and calcified plaque, as well as a higher coronary artery calcium score and segment stenosis score (all p<0.05), in the M+ compared with the M- group. M+ patients also had a significantly higher frequency of coronary artery calcium in the left main and anterior descending and right coronary arteries (all p<0.05), but not in the left circumflex.

CONCLUSIONS

Among patients with phenotypic FH, those with a genetically confirmed diagnosis had a higher frequency and severity of coronary atherosclerotic plaques, and specifically more advanced calcified plaques.

Familial Hypercholesterolaemia in 2020: A Leading Tier 1 Genomic Application

Familial hypercholesterolaemia (FH) is caused by a major genetic defect in the low-density lipoprotein (LDL) clearance pathway. Characterised by LDL-cholesterol elevation from birth, FH confers a significant risk for premature coronary artery disease (CAD) if overlooked and untreated. With risk exposure beginning at birth, early detection and intervention is crucial for the prevention of CAD. Lowering LDL-cholesterol with lifestyle and statin therapy can reduce the risk of CAD. However, most individuals with FH will not reach guideline recommended LDL-cholesterol targets. FH has an estimated prevalence of approximately 1:250 in the community. Multiple strategies are required for screening, diagnosing and treating FH. Recent publications on FH provide new data for developing models of care, including new therapies. This review provides an overview of FH and outlines some recent advances in the care of FH for the prevention of CAD in affected families. The future care of FH in Australia should be developed within the context of the National Health Genomics Policy Framework.

Clinical and genetic differences between heterozygous familial hypercholesterolemia patients with and without type 2 diabetes

INTRODUCTION AND OBJECTIVES

The lower prevalence of type 2 diabetes mellitus (T2DM) in patients with heterozygous familial hypercholesterolemia (HeFH) could explain why T2DM has not always been identified as an independent predictor of cardiovascular disease (CVD) in different familial hypercholesterolemia cohort studies. The aim of the present study was to evaluate clinical and genetic aspects of HeFH patients with T2DM in the dyslipidemia registry of the Spanish Arteriosclerosis Society.

METHODS

HeFH patients were classified according to the presence or absence of T2DM. The clinical, biochemical and genetic characteristics of the 2 groups were compared.

RESULTS

Of the 2301 patients with primary hypercholesterolemia included in the registry, 1724 with a probable or definite diagnosis according to the Dutch Lipid Clinic Network score were finally included. HeFH patients with T2DM had a higher rate of CVD and a less favorable lipid profile, with higher total cholesterol (366.9±86.7mg/dL vs 342.0±74.7mg/dL; mean difference 24.894; 95%CI, 5.840-43.949) and non-high-density lipoprotein cholesterol (316.9±87.8mg/dL vs 286.4±75.4mg/dL; mean difference 30.500; 95%CI, 11.211-49.790) levels. No significant differences were found between the groups concerning the specific type of HeFH-causing mutation (P=.720). After adjustment for major risk factors, logistic regression analysis confirmed a relationship between T2DM and the presence of CVD (OR, 2.01; 95%CI, 1.18-3.43; P=.010).

CONCLUSIONS

HeFH patients with T2DM have a higher rate of CVD and a less favorable lipid profile, regardless of genetic mutation type. In these patients, T2DM is associated with the presence of CVD.

A modified algorithm with lipoprotein(a) added for diagnosis of familial hypercholesterolemia

Background

Previous studies have observed that high level of lipoprotein (a) [Lp(a)] was common in the phenotypic familial hypercholesterolemia (FH) and may explain part of the clinical diagnosis of FH.

Hypothesis

We aim to develop a modified model including Lp(a) and compare its diagnostic performance with Dutch Lipid Clinic Network (DLCN) criteria.

Methods

Data of 10 449 individuals were utilized for the model establishment (7806 for derivation and 2643 for validation) from January 2011 to March 2018. The novel score model was modified on the basis of DLCN. Furthermore, 718 patients were screened for LDLR, APOB, and PCSK9 gene mutations.

Results

The novel modified model consisted of untreated low‐density lipoprotein cholesterol (LDL‐C) level, Lp(a), personal premature coronary heart disease (CHD), tendon xanthomas and family history of CHD and/or hypercholesterolemia. It has shown high discrimination (area under curve [AUC] 0.991, 95% confidence interval [CI[ 0.988‐0.994, P < .001) for distinguishing clinical FH from non‐FH diagnosed using DLCN. Furthermore, a concordance analysis was performed to compare the modified model with DLCN and it showed a good agreement with DLCN (κ = 0.765). External validation of the novel model also showed good accordance (κ = 0.700). Further genetic analysis showed that the agreements between the new model and mutation improved a little compared to that between DLCN and mutation.

Conclusions

The novel modified model, including Lp(a), could provide new insights into FH diagnosis in Chinese population with more concerns on the patients with high level of Lp(a).

To test, or not to test: that is the question for the future of lipoprotein(a)

INTRODUCTION

Lipoprotein(a) [Lp(a)] is a potent, highly heritable and common risk factor for atherosclerotic cardiovascular disease (ASCVD). Evidence for a causal association between elevated Lp(a) and ASCVD has been provided by large epidemiological investigations that have demonstrated a curvilinear association with increased risk, as well as from genetic examinations and cellular and transgenic animal studies. Although there are several therapies available for lowering Lp(a), none are selective for Lp(a) and there is no clinical trial data that has specifically shown that lowering Lp(a) reduces the risk of ASCVD. Hence, screening for elevated Lp(a) is not routinely incorporated into clinical practice. Areas covered: This paper reviews the current evidence supporting the causal role of Lp(a) in the primary and secondary prevention of ASCVD, screening approaches for high Lp(a), current guidelines on testing Lp(a), and barriers to the routine screening of elevated Lp(a) in clinical practice. Expert opinion: At present, there is a moderate level of evidence supporting the routine screening of elevated Lp(a). Current guidelines recommend testing for elevated Lp(a) in individuals at intermediate or high risk of ASCVD.

Comparative aspects of the care of familial hypercholesterolemia in the "Ten Countries Study"

BACKGROUND

There is a lack of information on the health care of familial hypercholesterolemia (FH).

OBJECTIVE

The objective of this study was to compare the health care of FH in countries of the Asia-Pacific region and Southern Hemisphere.

METHODS

A series of questionnaires were completed by key opinion leaders from selected specialist centers in 12 countries concerning aspects of the care of FH, including screening, diagnosis, risk assessment, treatment, teaching/training, and research; the United Kingdom (UK) was used as the international benchmark.

RESULTS

The estimated percentage of patients diagnosed with the condition was low (overall <3%) in all countries, compared with ∼15% in the UK. Underdetection of FH was associated with government expenditure on health care (ϰ = 0.667, P < .05). Opportunistic and systematic screening methods, and the Dutch Lipid Clinic Network criteria were most commonly used to detect FH; genetic testing was infrequently used. Noninvasive imaging of coronary calcium and/or carotid plaques was underutilized in risk assessment. Patients with FH were generally not adequately treated, with <30% of patients achieving guideline recommended low-density lipoprotein cholesterol targets on conventional therapies. Treatment gaps included suboptimal availability and use of lipoprotein apheresis and proprotein convertase subtilsin-kexin type 9 inhibitors. A deficit of FH registries, training programs, and publications were identified in less economically developed countries. The demonstration of cost-effectiveness for cascade screening, genetic testing, and specialized treatments were significantly associated with the availability of subsidies from the health care system (ϰ = 0.571-0.800, P < .05).

CONCLUSION

We identified important gaps across the continuum of care for FH, particularly in less economically developed countries. Wider implementation of primary and pediatric care, telehealth services, patient support groups, education/training programs, research activities, and health technology assessments are needed to improve the care of patients with FH in these countries.

Long-term lipoprotein apheresis in the treatment of severe familial hypercholesterolemia refractory to high intensity statin therapy: Three year experience at a lipoprotein apheresis centre

BACKGROUND

Severe familial hypercholesterolemia (FH) individuals, refractory to conventional lipidlowering medications are at exceptionally high risk of cardiovascular events. The established therapeutic option of last choice is lipoprotein apheresis (LA). Herein, it was sought to investigate the clinical usefulness of LA in a highly selected group of severe heterozygous FH (HeFH), as recently described by the International Atherosclerosis Society (IAS), for their efficacy in lipid reduction and safety.

METHODS

Efficacy and safety of LA were investigated in 318 sessions of 7 severe HeFH females with cardiovascular disease, over a mean period of 26.9 ± 6.5 months. Relative reduction of low density lipoprotein cholesterol (LDL-C) ≥ 60%, clinical complications and vascular access problems were evaluated and compared between the direct adsorption of lipoproteins (DALI) and lipoprotein filtration (Membrane Filtration Optimized Novel Extracorporeal Treatment [MONET]). Additionally, lipoprotein (a) [Lp(a)], total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), triglycerides (TG) and fibrinogen concentrations were investigated.

RESULTS

The relative reduction of LDL-C, TC, TG and Lp(a) were 69.4 ± 12.9%, 59.7 ± 9.1, 51.5 ± ± 14.2% and 71.3 ± 14.4%, respectively. A similar efficacy was found in both systems in LDL-C removal. DALI system led to larger depletions of Lp(a) (80.0 [76-83]% vs. 73.0 [64.7-78.8]%; p < 0.001). The frequency of clinical side effects and vascular access problems were low (8.5%).

CONCLUSIONS

Long-term LA in severe HeFH individuals is safe and efficiently reduces LDL-C and Lp(a). Higher efficacy of the DALI system than MONET in Lp(a) removal may indicate the need for individualized application of the LA system in severe HeFH individuals.

Predicting cardiovascular disease in familial hypercholesterolemia

PURPOSE OF REVIEW

Familial hypercholesterolemia is a frequent genetic disease associated with a high lifetime risk of cardiovascular disease (CVD). Statins are the cornerstone of treatment of familial hypercholesterolemia; however, with the advent of novel LDL-cholesterol lowering therapies, it has become necessary to identify familial hypercholesterolemia subjects presenting a significant residual CVD risk. The aim of this review is to provide an update on the recent literature concerning cardiovascular risk stratification in familial hypercholesterolemia.

RECENT FINDINGS

Recently, several clinical and genetic factors have been shown to be independent predictors of CVD in familial hypercholesterolemia. These include clinical scores such as the Montreal-FH-SCORE, novel protein biomarkers, carotid plaque score and genetic predictors such as genetic risk scores as well as single-nucleotide polymorphisms.

SUMMARY

Although there has been recent progress in cardiovascular risk stratification in familial hypercholesterolemia, there is still a need to further refine our knowledge concerning phenotype modifiers in this disease. Indeed, current known predictors do not explain the entirety of cardiovascular risk. More precise individual risk stratification in familial hypercholesterolemia could help to better tailor the proper therapy for each patient.

Guidelines for Diagnosis and Treatment of Familial Hypercholesterolemia 2017

Statement1. Familial hypercholesterolemia (FH) is an autosomal hereditary disease with the 3 major clinical features of hyper-LDL-cholesterolemia, premature coronary artery disease and tendon and skin xanthomas. As there is a considerably high risk of coronary artery disease (CAD), in addition to early diagnosis and intensive treatment, family screening (cascade screening) is required (Recommendation level A) 2. For a diagnosis of FH, at least 2 of the following criteria should be satisfied:① LDL-C ≥180 mg/dL, ② Tendon/skin xanthomas, ③ History of FH or premature CAD within 2nd degree blood relatives (Recommendation level A) 3. Intensive lipid-lowering therapy is necessary for the treatment of FH. First-line drug should be statins. (Recommendation level A, Evidence level 3) 4. Screening for CAD as well as asymptomatic atherosclerosis should be conducted periodically in FH patients. (Recommendation level A) 5. For homozygous FH, consider LDL apheresis and treatment with PCSK9 inhibitors or MTP inhibitors. (Recommendation level A) 6. For severe forms of heterozygous FH who have resistant to drug therapy, consider PCSK9 inhibitors and LDL apheresis. (Recommendation level A) 7. Refer FH homozygotes as well as heterozygotes who are resistant to drug therapy, who are children or are pregnant or have the desire to bear children to a specialist. (Recommendation level A).

Elevated lipoprotein(a) and low-density lipoprotein cholesterol as predictors of the severity and complexity of angiographic lesions in patients with premature coronary artery disease

BACKGROUND

Elevated lipoprotein(a) (Lp[a]) and low-density lipoprotein (LDL) cholesterol are important inheritable risk factors for premature coronary artery disease (CAD). Lp(a) mediates cardiovascular risk through prothrombotic, proinflammatory, and proatherogenic properties. The association of Lp(a) and LDL cholesterol with angiographic disease severity and complexity in patients with premature CAD has yet to be established.

OBJECTIVE

To investigate the relationship of Lp(a) and LDL cholesterol with the severity and complexity of coronary artery lesions using the SYNergy between percutaneous coronary intervention with TAXUS and Cardiac Surgery (SYNTAX) and Gensini scores, in patients with premature CAD.

METHODS

Plasma Lp(a) levels were consecutively measured by an automated latex-enhanced immunoassay in 147 patients with premature coronary events (aged <60 years). Elevated Lp(a) was defined as >0.5 g/L, and elevated LDL cholesterol as an untreated LDL cholesterol of >5.0 mmol/L (>193 mg/dL). Demographical, biochemical, and clinical data were retrospectively collected from medical records. SYNTAX and Gensini scores were independently assessed by 2 investigators.

RESULTS

Patients were subdivided into tertiles using SYNTAX scores. The proportion of patients with elevated Lp(a) and elevated LDL cholesterol were significantly higher in patients with higher SYNTAX and Gensini scores (P < .05). In multivariate analysis (adjusting for age, diabetes, hypertension, and previous coronary event), elevated Lp(a) and elevated LDL cholesterol remained significant, independent predictors of higher SYNTAX and Gensini scores (P < .05). Patients with both elevated Lp(a) and elevated LDL cholesterol constituted most of the patients in the highest SYNTAX tertile, while patients with nonelevated Lp(a) and nonelevated LDL cholesterol were predominantly in the lowest SYNTAX tertile (P < .05).

CONCLUSION

In patients with premature CAD, elevated Lp(a) and LDL cholesterol (in a range consistent with familial hypercholesterolemia) were significant, independent predictors of the severity of CAD. Both lipid disorders should be routinely screened for in younger patients presenting to the coronary care unit.

A Comparative Analysis of Phenotypic Predictors of Mutations in Familial Hypercholesterolemia

CONTEXT

The gold standard for diagnosing familial hypercholesterolemia (FH) is identification of a causative pathogenic mutation. However, genetic testing is expensive and not widely available.

OBJECTIVE

To compare the validity of the Dutch Lipid Clinic Network (DLCN), Simon Broome (SB), Make Early Diagnosis to Prevent Early Deaths (MEDPED), and American Heart Association (AHA) criteria in predicting an FH-causing mutation.

DESIGN, SETTING, AND PATIENTS

An adult cohort of unrelated patients referred to a lipid clinic for genetic testing.

MAIN OUTCOME MEASURES

Odds ratio (OR), area under the curve (AUC), sensitivity, and specificity.

RESULTS

A pathogenic FH-causing mutation was detected in 30% of 885 patients tested. Elevated low-density lipoprotein (LDL) cholesterol and personal or family history of tendon xanthomata were independent predictors of a mutation (OR range 5.3 to 16.1, P < 0.001). Prediction of a mutation for the DLCN and SB definite and MEDPED criteria (ORs 9.4, 11.7, and 10.5, respectively) was higher than with the AHA criteria (OR 4.67). The balance of sensitivity and specificity was in decreasing order DLCN definite (Youden Index 0.487), MEDPED (0.457), SB definite (0.274), and AHA criteria (0.253), AUC being significantly higher with DLCN definite and MEDPED than other criteria (P < 0.05). Pretreatment LDL cholesterol and tendon xanthomata had the highest AUC in predicting a mutation.

CONCLUSIONS

The DLCN, SB, and MEDPED criteria are valid predictors of an FH-causing mutation in patients referred to a lipid clinic, but concordance between these phenotypic criteria is only moderate. Use of pretreatment LDL cholesterol and tendon xanthomata alone may be particularly useful for deciding who should be genetically tested for FH.

Lipoprotein(a) level associates with coronary artery disease rather than carotid lesions in patients with familial hypercholesterolemia

BACKGROUND

Lipoprotein(a) [Lp(a)] level is a novel risk factor for atherosclerotic cardiovascular disease in patients with familial hypercholesterolemia (FH), while its impact on the different sites of arteries remains undetermined. We aim to examine the associations of Lp(a) levels with coronary and carotid atherosclerosis in patients with heterozygous FH (HeFH).

METHODS

A total of 148 patients with HeFH who have received carotid ultrasonography and coronary angiography due to chest pain were enrolled. Plasma Lp(a) was measured using immunoturbidimetric method. Finally, the associations between Lp(a) and coronary as well as carotid lesions were evaluated.

RESULTS

Patients with Lp(a) ≥ 300 mg/L had similar carotid intima-media thickness (IMT, 0.782 ± 0.16 mm vs 0.798 ± 0.18 mm, P = .579) and plaque prevalence (66.7% vs 65%, P = .833) compared to those with Lp(a) < 300 mg/L, but had a higher prevalence of coronary artery disease (CAD, 69.7% vs 50.0%, P = .016) and higher Gensini score (GS, median 27 vs 3, P = .006). Moreover, no correlations were found between carotid mean IMT with either Lp(a) level or Lp(a) year score, while positive relation of Lp(a) with GS did. Multivariate regression analysis revealed that Lp(a), Lp(a) year score, and Lp(a) ≥ 300 g/L were all independent predictors for the presence of CAD (OR = 4.99, P = .007; OR = 4.73, P = .009; OR = 4.46, P = .006, respectively) but not for carotid plaques.

CONCLUSIONS

This study suggested that Lp(a) level was associated with the presence and severity of CAD but not with carotid atherosclerosis in patients with HeFH.

Elevated lipoprotein(a) and familial hypercholesterolemia in the coronary care unit: Between Scylla and Charybdis

BACKGROUND

Elevated lipoprotein(a) (Lp[a]) and familial hypercholesterolemia (FH) are inherited lipid disorders. Their frequencies, coexistence, and associations with premature coronary artery disease (CAD) in patients admitted to the coronary care unit (CCU) remain to be defined.

HYPOTHESIS

Elevated Lp(a) and FH are commonly encountered among CCU patients and independently associated with increased premature CAD risk.

METHODS

Plasma Lp(a) concentrations were measured in consecutive patients admitted to the CCU with an acute coronary syndrome (ACS) or prior history of CAD for 6.5 months. Elevated Lp(a) was defined as concentrations ≥0.5 g/L. Patients with LDL-C ≥ 5 mmol/L exhibited phenotypic FH. Premature CAD was diagnosed in those age < 60 years, and the relationship between this and elevated Lp(a) and FH was determined by logistic regression.

RESULTS

316 patients were screened; 163 (51.6%) had premature CAD. Overall, elevated Lp(a) and FH were identified in 27.0% and 11.6% of patients, respectively. Both disorders were detected in 4.4% of individuals. Elevated Lp(a) (32.0% vs 22.2%; P = 0.019) and FH phenotype (15.5% vs 8.0%; P = 0.052) were more common with premature vs nonpremature CAD. Elevated Lp(a) alone conferred a 1.9-fold, FH alone a 3.2-fold, and the combination a 5.3-fold increased risk of premature CAD (P = 0.005).

CONCLUSIONS

Elevated Lp(a) and phenotypic FH were commonly encountered and more frequent with premature CAD. The combination of both disorders is especially associated with increased CAD risk. Patients admitted to the CCU with ACS or previously documented CAD should be routinely screened for elevated Lp(a) and FH.

An enquiry based on a standardised questionnaire into knowledge, awareness and preferences concerning the care of familial hypercholesterolaemia among primary care physicians in the Asia-Pacific region: the "Ten Countries Study"

OBJECTIVE

To determine physicians' knowledge, awareness and preferences regarding the care of familial hypercholesterolaemia (FH) in the Asia-Pacific region.

SETTING

A formal questionnaire was anonymously completed by physicians from different countries/regions in the Asia-Pacific. The survey sought responses relating to general familiarity, awareness of management guidelines, identification (clinical characteristics and lipid profile), prevalence and inheritance, extent of elevation in risk of cardiovascular disease (CVD) and practice on screening and treatment.

PARTICIPANTS

Practising community physicians from Australia, Japan, Malaysia, South Korea, Philippines, Hong Kong, China, Vietnam and Taiwan were recruited to complete the questionnaire, with the UK as the international benchmark.

PRIMARY OUTCOME

An assessment and comparison of the knowledge, awareness and preferences of FH among physicians in 10 different countries/regions.

RESULTS

1078 physicians completed the questionnaire from the Asia-Pacific region; only 34% considered themselves to be familiar with FH. 72% correctly described FH and 65% identified the typical lipid profile, with a higher proportion of physicians from Japan and China selecting the correct FH definition and lipid profile compared with those from Vietnam and Philippines. However, less than half of the physician were aware of national or international management guidelines; this was significantly worse than physicians from the UK (35% vs 61%, p<0.001). Knowledge of prevalence (24%), inheritability (41%) and CVD risk (9%) of FH were also suboptimal. The majority of the physicians considered laboratory interpretative commenting as being useful (81%) and statin therapy as an appropriate cholesterol-lowering therapy (89%) for FH management.

CONCLUSIONS

The study identified important gaps, which are readily addressable, in the awareness and knowledge of FH among physicians in the region. Implementation of country-specific guidelines and extensive work in FH education and awareness programmes are imperative to improve the care of FH in the region.