Clinical experience of scoring criteria for Familial Hypercholesterolaemia (FH) genetic testing in Wales

Performance of LDL-C only compared to the Dutch Lipid Clinic Network Score for screening of familial hypercholesterolaemia: the Austrian experience and literature review

AIMS

Familial hypercholesterolaemia (FH) is a severely underdiagnosed, inherited disease, causing dyslipidaemia and premature atherosclerotic cardiovascular disease. In order to facilitate screening in a broad clinical spectrum, we aimed to analyse the current yield of routine genetic diagnostics for FH and to evaluate the performance of the Dutch Lipid Clinic Network Score (DLCNS) compared to a single value, the off-treatment LDL-cholesterol exceeding 190 mg/dL.

METHODS AND RESULTS

We investigated all patients that underwent molecular genotyping routinely performed for FH over a 4-year period in two Austrian specialist lipid clinics. Variants reported in FH-causing genes including LDLR, APOB, PCSK9, LDLRAP, and APOE were collected and classified. For clinical classification, the DLCNS was calculated retrospectively and compared to the original scores documented in patient charts. Additionally, a literature review on comparisons of DLCNS to LDL-C was performed. Of 469 patients tested, 21.3% had a disease-causing variant. A median of 3 out of 8 (excluding genotyping results and LDL-C) DLCNS criteria were unavailable. DLCNS was documented in 48% of cases, with significant discrepancies compared to retrospective scoring (P < 0.001). DLCNS did not outperform off-treatment LDL-C alone (Δ = 0.006; P = 0.660), analogously to several reports identified in the literature. A single cut-off of 190 mg/dL LDL-C compared to DLCNS ≥ 6 showed excellent sensitivity (84.9% vs. 53.8%) and acceptable specificity (39.0% vs. 84.1%).

CONCLUSION

Missing criteria and severe discrepancies observed between retrospective and on-site scoring by treating physicians were highly prevalent, confirming limited utility of DLCNS in clinical routine and warranting a single off-treatment LDL-C cut-off of 190 mg/dL for enhanced index-case identification.

SYNTAX I score is associated with genetically confirmed familial hypercholesterolemia in chinese patients with coronary heart disease

BACKGROUND

Familial hypercholesterolemia (FH) is a genetically inherited disorder caused by monogenic mutations or polygenic deleterious variants. Patients with FH innate with significantly elevated risks for coronary heart disease (CHD). FH prevalence based on genetic testing in Chinese CHD patients is missing. Whether classical index of coronary atherosclerosis severity can be used as indicators of FH needs to be explored. To investigate the FH prevalence in Chinese CHD patients and the association of SYNTAX I score with FH genotype.

METHODS

The monogenic and polygenic FH related genes were genotyped in 400 consecutively enrolled CHD patients. The clinical characteristics and SYNTAX I scores were analyzed in a retrospective nested case-control study.

RESULTS

The prevalence of genetically confirmed FH in our CHD cohort was 8.75%. The cLDL-C level, SYNTAX I scores and incidences of triple vessel lesions in FH patients were significantly higher, while cLDL-C and SYNTAX I scores were independent risk factors for FH. Furthermore, cLDL-C levels of polygenic FH were significantly lower than monogenic FH, while their severity of coronary atherosclerosis was comparable.

CONCLUSIONS

Our study revealed that the SYNTAX I score was an independent risk factor for FH. Besides, polygenic origin of FH should be taken into consideration for CHD patients suspected of FH.

The singular French PCSK9-p.Ser127Arg gain-of-function variant: A significant player in cholesterol levels from a 775-year-old common ancestor

BACKGROUND AND AIMS

PCSK9 is a key regulator of LDL-cholesterol levels. PCSK9 gain of function variants (GOFVs) cause autosomal dominant hypercholesterolemia (ADH). The first described PCSK9-GOFV, p.Ser127Arg, almost exclusively reported in France, represents 67 % of the PCSK9 French GOFVs due to a founder effect. Few other carriers are reported in South Africa and Norway. This study aims to estimate when the common ancestor lived and to describe a cohort of p.Ser127Arg carriers.

METHODS

Eight families and 14 p.Ser127Arg carriers were genotyped and phenotyped. Haplotypes were constructed using 11 microsatellites around PCSK9 and 6 intragenic single nucleotide polymorphisms (SNPs). To add to the biological analysis, eight additional p.Ser127Arg carriers, 12 carriers of other PCSK9-GOFVs, 93 LDLR loss of function variant (LOFV) carriers and 49 non-carriers subjects were phenotyped.

RESULTS

The most common ancestor of p.Ser127Arg was estimated to have lived 775 years ago [95 % CI: 575-1075]. French Protestants exiled after the revocation of the Edict of Nantes in 1685 AD likely brought the variant to South Africa and Norway. As expected for ADH subjects, carriers of LDLR-LOFV, the p.Ser127Arg, or other PCSK9-GOFVs showed significantly higher LDL-C levels than that of the non-carriers. Interestingly, LDL-C levels are higher for LDLR-LOFVs and for the reduced secreted p.Ser127Arg than for secreted PCSK9-GOFVs, suggesting a greater effect of the p.Ser127Arg. Conversely, HDL-C was significantly lower for LDLR-LOFV and p.Ser127Arg carriers.

CONCLUSIONS

This first report from a large cohort of PCSK9-p.Ser127Arg carriers provides observations suggesting a stronger hypercholesterolemic potential of the mutated pro-PCSK9 compared with the secreted mature protein. This work also provides additional data to support the association between PCSK9 and HDL metabolism, and molecular evidence that this variant appeared in France around 1248 AD (Graphical Abstract = Fig. 1).

The Lipoprotein Profile Evaluated by 1H-NMR Improves the Performance of Genetic Testing in Familial Hypercholesterolemia

BACKGROUND

The familial hypercholesterolemia (FH) diagnosis is based on clinical and genetic criteria. A relevant proportion of FH patients fulfilling the criteria for definite FH have negative genetic testing. Increasing the identification of true genetic-based FH is a clinical challenge. Deepening the analysis of lipoprotein alterations could help increase the yield of genetic testing. We evaluated whether the number, size, and composition of lipoproteins assessed by 1H-NMR could increase the identification of FH patients with pathogenic gene variants.

METHODS

We studied 294 clinically definite FH patients, 222 (75.5%) with positive genetic testing, as the discovery cohort. As an external validation cohort, we studied 88 children with FH, 72 (81%) with positive genetic testing. The advanced lipoprotein test based on 1H-NMR (Liposcale®) was performed at baseline after a lipid-lowering drug washout of at least 6 weeks. The association of variables with genetic variants was evaluated by random forest and logistic regression. Areas under the curve (AUCs) were calculated. A predictive formula was developed and applied to the validation cohort.

RESULTS

A formula derived from nuclear magnetic resonance (NMR) lipoprotein analyses improved the identification of genetically positive FH patients beyond low-density lipoprotein (LDL)-cholesterol levels (AUC = 0.87). The parameters contributing the most to the identification formula were LDL particle number, high-density lipoprotein size, and remnant cholesterol. The formula also increases the classification of FH children with a pathogenic genetic variation.

CONCLUSION

NMR lipoprotein profile analysis identifies differences beyond standard lipid parameters that help identify FH with a positive pathogenic gene variant, increasing the yield of genetic testing in FH patients.

Prevalence of genetically diagnosed familial hypercholesterolemia in Vietnamese patients with premature acute myocardial infarction

Familial hypercholesterolemia (FH) is a genetic disorder that results in elevated low-density lipoprotein cholesterol (LDL-C) levels, which manifest early in the first decades of life. It is a major cause of premature coronary artery disease worldwide, leading to significant public health challenges. The prevalence of genetically determined FH in patients with premature coronary artery disease remains underestimated, particularly in developing countries. This study aimed to assess the prevalence of genetically defined FH in Vietnamese patients with premature acute myocardial infarction (AMI) in the Vietnamese population. This cross-sectional study enrolled 218 consecutive patients diagnosed with premature AMI who underwent coronary angiography. The low-density lipoprotein receptor (LDLR), apolipoprotein B, and proprotein convertase subtilisin-kexin type 9 genes were analyzed by next-generation sequencing. FH was diagnosed according to Dutch Lipid Clinic Network criteria. Among the patients with premature AMI who underwent coronary angiography, the mean age was 46.9 ± 6.1 years, with a predominance of males (83.9%). The prevalence of potential FH diagnosed using Dutch Lipid Clinic Network criteria was 14.7% (definite FH, 6.0%; probable FH, 8.7%). Pathogenic or likely pathogenic variants in LDLR, apolipoprotein B, and proprotein convertase subtilisin-kexin type 9 were found in 9 of 218 patients (4.1%), all of which were causative mutations in LDLR. Patients with premature AMI and FH had significantly greater LDL-C levels (217.6 vs 125.7 mg/dL) and more severe coronary artery lesions, as assessed by the Gensini score (100.3 vs 60.5), than did those in the No FH group. The prevalence of genetically determined FH among Vietnamese patients with premature AMI is relatively high. Screening and diagnosis of hereditary conditions in patients with premature AMI are essential to improve early detection and management and reduce the burden of coronary artery disease in this population.

Challenges and opportunities for identifying people with Familial hypercholesterolaemia in the UK: Evidence from the National FH PASS database

BACKGROUND

Familial Hypercholesterolaemia (FH) is a monogenic disorder that causes high levels of low-density lipoprotein (LDL) cholesterol. Cascade testing, where relatives of known individuals with FH ('index') are genetically tested, is effective and cost-effective, but implementation in the UK varies.

OBJECTIVE

This study aims to provide evidence on current UK FH cascade yields and to identify common obstacles cascade services face and individual- and service-level predictors of success.

METHODS

Electronic health records from 875 index families and 5,958 linked relatives in the UK's Welsh and Wessex FH services (2019) were used to explore causes for non-testing and to estimate testing rates, detection yields, and how relative characteristics and contact methods relate to the probability of relatives being tested (using logistic regression).

RESULTS

In Wales (Wessex), families included 7.35 (7.01) members on average, with 2.41 (1.66) relatives tested and 1.35 (0.96) diagnosed with FH per index. Cascade testing is limited by individualised circumstances (too young, not at-risk, etc.) and FH services' reach, with approximately one in four relatives out-of-area. In Wales, first-degree relatives (odds ratio (OR):1.55 [95 % confidence interval (CI):1.28,1.88]) and directly contacted relatives (OR:2.11 [CI:1.66,2.69]) were more likely to be tested. In Wales and Wessex, women were more likely to be tested than men (ORs:1.53 [CI:1.28,1.85] and 1.74 [CI:1.32,2.27]).

CONCLUSION

In Wales and Wessex less than a third of relatives of an index are tested for FH. Improvements are likely possible by integrating geographically dispersed families into cascade testing, services directly contacting relatives where possible, and finding new ways to encourage participation, particularly amongst men.

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.

Assessment of ethnic inequalities in diagnostic coding of familial hypercholesterolaemia (FH): A cross-sectional database study in Lambeth, South London

BACKGROUND AND AIMS

Differences in the perceived prevalence of familial hypercholesterolemia (FH) by ethnicity are unclear. In this study, we aimed to assess the prevalence, determinants and management of diagnostically-coded FH in an ethnically diverse population in South London.

METHODS

A cross-sectional analysis of 40 practices in 332,357 adult patients in Lambeth was undertaken. Factors affecting a (clinically coded) diagnosis of FH were investigated by multi-level logistic regression adjusted for socio-demographic and lifestyle factors, co-morbidities, and medications.

RESULTS

The age-adjusted FH % prevalence rate (OR, 95%CI) ranged from 0.10 to 1.11, 0.00-1.31. Lower rates of FH coding were associated with age (0.96, 0.96-0.97) and male gender (0.75, 0.65-0.87), p < 0.001. Compared to a White British reference group, a higher likelihood of coded FH was noted in Other Asians (1.33, 1.01-1.76), p = 0.05, with lower rates in Black Africans (0.50, 0.37-0.68), p < 0.001, Indians (0.55, 0.34-0.89) p = 0.02, and in Black Caribbeans (0.60, 0.44-0.81), p = 0.001. The overall prevalence using Simon Broome criteria was 0.1%; we were unable to provide ethnic specific estimates due to low numbers. Lower likelihoods of FH coding (OR, 95%CI) were seen in non-native English speakers (0.66, 0.53-0.81), most deprived income quintile (0.68, 0.52-0.88), smokers (0.68,0.55-0.85), hypertension (0.62, 0.52-0.74), chronic kidney disease (0.64, 0.41-0.99), obesity (0.80, 0.67-0.95), diabetes (0.31, 0.25-0.39) and CVD (0.47, 0.36-0.63). 20% of FH coded patients were not prescribed lipid-lowering medications, p < 0.001.

CONCLUSIONS

Inequalities in diagnostic coding of FH patients exist. Lower likelihoods of diagnosed FH were seen in Black African, Black Caribbean and Indian ethnic groups, in contrast to higher diagnoses in White and Other Asian ethnic groups. Hypercholesterolaemia requiring statin therapy was associated with FH diagnosis, however, the presence of cardiovascular disease (CVD) risk factors lowered the diagnosis rate for FH.

International Atherosclerosis Society guidance for implementing best practice in the care of familial hypercholesterolaemia

This contemporary, international, evidence-informed guidance aims to achieve the greatest good for the greatest number of people with familial hypercholesterolaemia (FH) across different countries. FH, a family of monogenic defects in the hepatic LDL clearance pathway, is a preventable cause of premature coronary artery disease and death. Worldwide, 35 million people have FH, but most remain undiagnosed or undertreated. Current FH care is guided by a useful and diverse group of evidence-based guidelines, with some primarily directed at cholesterol management and some that are country-specific. However, none of these guidelines provides a comprehensive overview of FH care that includes both the lifelong components of clinical practice and strategies for implementation. Therefore, a group of international experts systematically developed this guidance to compile clinical strategies from existing evidence-based guidelines for the detection (screening, diagnosis, genetic testing and counselling) and management (risk stratification, treatment of adults or children with heterozygous or homozygous FH, therapy during pregnancy and use of apheresis) of patients with FH, update evidence-informed clinical recommendations, and develop and integrate consensus-based implementation strategies at the patient, provider and health-care system levels, with the aim of maximizing the potential benefit for at-risk patients and their families worldwide.

Alternative cascade-testing protocols for identifying and managing patients with familial hypercholesterolaemia: systematic reviews, qualitative study and cost-effectiveness analysis

Background

Cascade testing the relatives of people with familial hypercholesterolaemia is an efficient approach to identifying familial hypercholesterolaemia. The cascade-testing protocol starts with identifying an index patient with familial hypercholesterolaemia, followed by one of three approaches to contact other relatives: indirect approach, whereby index patients contact their relatives; direct approach, whereby the specialist contacts the relatives; or a combination of both direct and indirect approaches. However, it is unclear which protocol may be most effective.

Objectives

The objectives were to determine the yield of cases from different cascade-testing protocols, treatment patterns, and short- and long-term outcomes for people with familial hypercholesterolaemia; to evaluate the cost-effectiveness of alternative protocols for familial hypercholesterolaemia cascade testing; and to qualitatively assess the acceptability of different cascade-testing protocols to individuals and families with familial hypercholesterolaemia, and to health-care providers.

Design and methods

This study comprised systematic reviews and analysis of three data sets: PASS (PASS Software, Rijswijk, the Netherlands) hospital familial hypercholesterolaemia databases, the Clinical Practice Research Datalink (CPRD)-Hospital Episode Statistics (HES) linked primary-secondary care data set, and a specialist familial hypercholesterolaemia register. Cost-effectiveness modelling, incorporating preceding analyses, was undertaken. Acceptability was examined in interviews with patients, relatives and health-care professionals.

Result

Systematic review of protocols: based on data from 4 of the 24 studies, the combined approach led to a slightly higher yield of relatives tested [40%, 95% confidence interval (CI) 37% to 42%] than the direct (33%, 95% CI 28% to 39%) or indirect approaches alone (34%, 95% CI 30% to 37%). The PASS databases identified that those contacted directly were more likely to complete cascade testing (p < 0.01); the CPRD-HES data set indicated that 70% did not achieve target treatment levels, and demonstrated increased cardiovascular disease risk among these individuals, compared with controls (hazard ratio 9.14, 95% CI 8.55 to 9.76). The specialist familial hypercholesterolaemia register confirmed excessive cardiovascular morbidity (standardised morbidity ratio 7.17, 95% CI 6.79 to 7.56). Cost-effectiveness modelling found a net health gain from diagnosis of -0.27 to 2.51 quality-adjusted life-years at the willingness-to-pay threshold of £15,000 per quality-adjusted life-year gained. The cost-effective protocols cascaded from genetically confirmed index cases by contacting first- and second-degree relatives simultaneously and directly. Interviews found a service-led direct-contact approach was more reliable, but combining direct and indirect approaches, guided by index patients and family relationships, may be more acceptable.

Limitations

Systematic reviews were not used in the economic analysis, as relevant studies were lacking or of poor quality. As only a proportion of those with primary care-coded familial hypercholesterolaemia are likely to actually have familial hypercholesterolaemia, CPRD analyses are likely to underestimate the true effect. The cost-effectiveness analysis required assumptions related to the long-term cardiovascular disease risk, the effect of treatment on cholesterol and the generalisability of estimates from the data sets. Interview recruitment was limited to white English-speaking participants.

Conclusions

Based on limited evidence, most cost-effective cascade-testing protocols, diagnosing most relatives, select index cases by genetic testing, with services directly contacting relatives, and contacting second-degree relatives even if first-degree relatives have not been tested. Combined approaches to contact relatives may be more suitable for some families.

Future work

Establish a long-term familial hypercholesterolaemia cohort, measuring cholesterol levels, treatment and cardiovascular outcomes. Conduct a randomised study comparing different approaches to contact relatives.

Study registration

This study is registered as PROSPERO CRD42018117445 and CRD42019125775.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 16. See the NIHR Journals Library website for further project information.

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.

Economic evaluations of predictive genetic testing: A scoping review

Predictive genetic testing can provide information about whether or not someone will develop or is likely to develop a specific condition at a later stage in life. Economic evaluation can assess the value of money for such testing. Studies on the economic evaluation of predictive genetic testing have been carried out in a variety of settings, and this research aims to conduct a scoping review of findings from these studies. We searched the PubMed, Web of Science, Embase, and Cochrane databases with combined search terms, from 2019 to 2022. Relevant studies from 2013 to 2019 in a previous systematic review were also included. The study followed the recommended stages for undertaking a scoping review. A total of 53 studies were included, including 33 studies from the previous review and 20 studies from the search of databases. A significant number of studies focused on the US, UK, and Australia (34%, 23%, and 11%). The most frequently included health conditions were cancer and cardiovascular diseases (68% and 19%). Over half of the studies compared predictive genetic testing with no genetic testing, and the majority of them concluded that at least some type of genetic testing was cost-effective compared to no testing (94%). Some studies stated that predictive genetic testing is becoming more cost-effective with the trend of lowering genetic testing costs. Studies on predictive genetic testing covered various health conditions, particularly cancer and cardiovascular diseases. Most studies indicated that predictive genetic testing is cost-effective compared to no testing.

Barriers and shortcomings in access to cardiovascular management and prevention for familial hypercholesterolemia during the COVID-19 pandemic

Familial hypercholesterolemia (FH) is a hereditary condition caused by mutations in the lipid pathway. The goal in managing FH is to reduce circulating low-density lipoprotein cholesterol and, therefore, reduce the risk of developing atherosclerotic cardiovascular disease (ASCVD). Because FH patients were considered high risk groups due to an increased susceptible for contracting COVID-19 infection, we hypothesized whether the effects of the pandemic hindered access to cardiovascular care. In this review, we conducted a literature search in databases Pubmed/Medline and ScienceDirect. We included a comprehensive analysis of findings from articles in English related and summarized the effects of the pandemic on cardiovascular care through direct and indirect effects. During the COVID-19 pandemic, FH patients presented with worse outcomes and prognosis, especially those that have suffered from early ASCVD. This caused avoidance in seeking care due to fear of transmission. The pandemic severely impacted consultations with lipidologists and cardiologists, causing a decline in lipid profile evaluations. Low socioeconomic communities and ethnic minorities were hit the hardest with job displacements and lacked healthcare coverage respectively, leading to treatment nonadherence. Lock-down restrictions promoted sedentary lifestyles and intake of fatty meals, but it is unclear whether these factors attenuated cardiovascular risk in FH. To prevent early atherogenesis in FH patients, universal screening programs, telemedicine, and lifestyle interventions are important recommendations that could improve outcomes in FH patients. However, the need to research in depth on the disproportionate impact within different subgroups should be the forefront of FH research.

Undiagnosed cardiovascular risk factors including elevated lipoprotein(a) in patients with ischaemic heart disease

Objectives

This study aims to investigate the prevalence of undiagnosed cardiovascular risk factors in patients with ischaemic heart disease (IHD).

Methods

We assessed the prevalence of previously undiagnosed cardiovascular risk factors, including elevated lipoprotein(a) [Lp(a)], among consenting patients with IHD who were admitted to hospital. Clinical information, including dietary history, from patients with newly diagnosed IHD and known IHD were compared.

Results

Of the 555 patients, 82.3% were males and 48.5% of Chinese ethnicity. Overall, 13.3% were newly diagnosed with hypertension, 14.8% with hypercholesterolemia, and 5% with type 2 diabetes (T2DM). Patients with newly diagnosed IHD, compared to those with known IHD, had a higher prevalence of new diagnoses of hypercholesterolemia (29.1% vs. 2.0%, p < 0.001), hypertension (24.5% vs. 3.4%, p < 0.001) and T2DM (7.3% vs. 3.1%, p = 0.023). Active smoking was prevalent in 28.3% of patients, and higher in newly diagnosed IHD (34.1% vs. 23.2%, p = 0.005). Elevated Lp(a) of ≥120 nmol/L was detected in 15.6% of all patients, none of whom were previously diagnosed. Dietary habits of >50% of patients in both groups did not meet national recommendations for fruits, vegetables, wholegrain and oily fish intake. However, patients with known IHD had a more regular omega-3 supplement intake (23.4% vs. 10.3%, p = 0.024).

Conclusion

Increased detection efforts is necessary to diagnose chronic metabolic diseases (hypertension, hypercholesterolemia, T2DM) especially among patients at high risk for IHD. Cardiovascular risk factors, in particular elevated Lp(a), smoking, and suboptimal dietary intake in patients with IHD deserve further attention.

Clinical characteristics of adult and paediatric patients with familial hypercholesterolemia: A real-life cross-sectional study from the Turkish National Database

BACKGROUND AND AIMS

Familial hypercholesterolemia (FH) is the most common cause of premature atherosclerotic cardiovascular disease (ASCVD). Türkiye is among the countries with the highest rate of ASCVD. However, no population-based study has been published so far on the prevalence of FH, demographic and clinical characteristics, burden of ASCVD, treatment compliance, and attainment of low-density lipoprotein cholesterol (LDL-C) targets.

METHODS

We performed a study using the Turkish Ministry of Health's national electronic health records involving 83,063,515 citizens as of December 2021 dating back 2016. Adults fulfilling the diagnostic criteria of definite or probable FH according to the Dutch Lipid Network Criteria (DLNC), and children and adolescents fulfilling the criteria of probable FH according to the European Atherosclerosis Society (EAS) Consensus Panel report formed the study population (n = 157,790). The primary endpoint was the prevalence of FH.

RESULTS

Probable or definite FH was detected in 0.63% (1 in 158) of the adults and 0.61% (1 in 164) of the total population. The proportion of adults with LDL-C levels >4.9 mmol/L (190 mg/dL) was 4.56% (1 in 22). The prevalence of FH among children and adolescents was 0.37% (1 in 270). Less than one-third of the children and adolescents, and two-thirds of young adults (aged 18-29) with FH were already diagnosed with dyslipidaemia. The proportion of adults and children and adolescents on lipid-lowering treatment (LLT) was 32.1% and 1.5%, respectively. The overall discontinuation rate of LLT was 65.8% among adults and 77.9% among children and adolescents. Almost no subjects on LLT were found to attain the target LDL-C levels.

CONCLUSIONS

This nationwide study showed a very high prevalence of FH in Türkiye. Patients with FH are diagnosed late and treated sub-optimally. Whether these findings may explain the high rates of premature ASCVD in Türkiye needs further investigation. These results denote the urgent need for country-wide initiatives for early diagnosis and effective management of FH patients.

Clinical Evaluation of Patients with Genetically Confirmed Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is the most common genetic disorder associated with premature atherosclerotic cardiovascular (CV) disease (ASCVD). However, it still is severely underdiagnosed. Initiating lipid-lowering therapy (LLT) in FH patients early in life can substantially reduce their ASCVD risk. As a result, identifying FH is of the utmost importance. The increasing availability of genetic testing may be useful in this regard. We aimed to evaluate the genetic profiles, clinical characteristics, and gender differences between the first consecutive patients referred for genetic testing with FH clinical suspicion in our institution (a Spanish cohort). Clinical information was reviewed, and all participants were sequenced for the main known genes related to FH: LDLR, APOB, PCSK9 (heterozygous FH), LDLRAP1 (autosomal recessive FH), and two other genes related to hyperlipidaemia (APOE and LIPA). The genetic yield was 32%. Their highest recorded LDLc levels were 294 ± 65 SD mg. However, most patients (79%) were under > 1 LLT medication, and their last mean LDLc levels were 135 ± 51 SD. LDLR c.2389+4A>G was one of the most frequent pathogenic/likely pathogenic variants and its carriers had significantly worse LDLc highest recorded levels (348 ± 61 SD vs. 282 ± 60 SD mg/dL, p = 0.002). Moreover, we identified an homozygous carrier of the pathogenic variant LDLRAP1 c.207delC (autosomal recessive FH). Both clinical and genetic hypercholesterolemia diagnosis was significantly established earlier in men than in women (25 years old ± 15 SD vs. 35 years old ± 19 SD, p = 0.02; and 43 ± 17 SD vs. 54 ± 19 SD, p = 0.02, respectively). Other important CV risk factors were found in 44% of the cohort. The prevalence of family history of premature ASCVD was high, whereas personal history was exceptional. Our finding reaffirms the importance of early detection of FH to initiate primary prevention strategies from a young age. Genetic testing can be very useful. As it enables familial cascade genetic testing, early prevention strategies can be extended to all available relatives at concealed high CV risk.

A Low-Frequency APOB p.(Pro955Ser) Variant Contributes to the Severity of/Variability in Familial Hypercholesterolemia

CONTEXT

Heterozygous familial hypercholesterolemia (HeFH) is caused by a rare pathogenic variant in the LDLR, APOB, and PCSK9 genes. However, the causative variants in these genes have not been identified in approximately 40% of HeFH patients.

OBJECTIVE

Our aim was to identify novel (or additional) genes/variants that contribute to HeFH.

METHODS

Whole-exome sequencing was performed for 215 family members from 122 families with HeFH without pathogenic variants in the LDLR or PCSK9 genes.

RESULTS

We could not find novel causative familial hypercholesterolemia (FH) genes/variants by family analysis. Next, we examined all APOB variants. Twenty-four nonsynonymous APOB variants were identified. The allele frequencies of the c.2863C > T:p.(Pro955Ser) variant in the HeFH probands and the general Japanese population were 0.15 and 0.034, respectively [odds ratio 4.9 (95% CI 3.4-7.1); P = 6.9 × 10-13]. The patients harboring the c.2863C > T:p.(Pro955Ser) variant accounted for 9.8% (n = 63) of unrelated patients with HeFH (n = 645). The penetrance of the c.2863C > T:p.(Pro955Ser) variant was low in the pedigree-based genetic analysis. In an in vitro assay, low-density lipoprotein (LDL) uptake from patients with the homozygous c.2863C > T:p.(Pro955Ser) variant was 44% of the LDL uptake from control subjects, and it was similar to that of the LDL uptake from patients with the known pathogenic heterozygous p.(Arg3527Gln) variant.

CONCLUSIONS

The low-frequency APOB c.2863C > T:p.(Pro955Ser) variant is not an FH-causative variant, but it has a moderate effect size in HeFH. These findings suggest that the combination of the APOB c.2863C > T:p.(Pro955Ser) variant and age, environmental factors, or other genetic factors contributes to the severity of or variability in the HeFH phenotype.

Electronic health record-based facilitation of familial hypercholesterolaemia detection sensitivity of different algorithms in genetically confirmed patients

Aims

Familial hypercholesterolaemia (FH) is a disorder of LDL cholesterol clearance, resulting in increased risk of cardiovascular disease. Recently, we developed a Dutch Lipid Clinic Network (DLCN) criteria-based algorithm to facilitate FH detection in electronic health records (EHRs). In this study, we investigated the sensitivity of this and other algorithms in a genetically confirmed FH population.

Methods and results

All patients with a healthcare insurance-related coded diagnosis of 'primary dyslipidaemia' between 2018 and 2020 were assessed for genetically confirmed FH. Data were extracted at the time of genetic confirmation of FH (T1) and during the first visit in 2018-2020 (T2). We assessed the sensitivity of algorithms on T1 and T2 for DLCN ≥ 6 and compared with other algorithms [familial hypercholesterolaemia case ascertainment tool (FAMCAT), Make Early Diagnoses to Prevent Early Death (MEDPED), and Simon Broome (SB)] using EHR-coded data and using all available data (i.e. including non-coded free text). 208 patients with genetically confirmed FH were included. The sensitivity (95% CI) on T1 and T2 with EHR-coded data for DLCN ≥ 6 was 19% (14-25%) and 22% (17-28%), respectively. When using all available data, the sensitivity for DLCN ≥ 6 was 26% (20-32%) on T1 and 28% (22-34%) on T2. For FAMCAT, the sensitivity with EHR-coded data on T1 was 74% (67-79%) and 32% (26-39%) on T2, whilst sensitivity with all available data was 81% on T1 (75-86%) and 45% (39-52%) on T2. For Make Early Diagnoses to Prevent Early Death MEDPED and SB, using all available data, the sensitivity on T1 was 31% (25-37%) and 17% (13-23%), respectively.

Conclusions

The FAMCAT algorithm had significantly better sensitivity than DLCN, MEDPED, and SB. FAMCAT has the best potential for FH case-finding using EHRs.

Assessing the genetic burden of familial hypercholesterolemia in a large middle eastern biobank

BACKGROUND

The genetic architecture underlying Familial Hypercholesterolemia (FH) in Middle Eastern Arabs is yet to be fully described, and approaches to assess this from population-wide biobanks are important for public health planning and personalized medicine.

METHODS

We evaluate the pilot phase cohort (n = 6,140 adults) of the Qatar Biobank (QBB) for FH using the Dutch Lipid Clinic Network (DLCN) criteria, followed by an in-depth characterization of all genetic alleles in known dominant (LDLR, APOB, and PCSK9) and recessive (LDLRAP1, ABCG5, ABCG8, and LIPA) FH-causing genes derived from whole-genome sequencing (WGS). We also investigate the utility of a globally established 12-SNP polygenic risk score to predict FH individuals in this cohort with Arab ancestry.

RESULTS

Using DLCN criteria, we identify eight (0.1%) 'definite', 41 (0.7%) 'probable' and 334 (5.4%) 'possible' FH individuals, estimating a prevalence of 'definite or probable' FH in the Qatari cohort of ~ 1:125. We identify ten previously known pathogenic single-nucleotide variants (SNVs) and 14 putatively novel SNVs, as well as one novel copy number variant in PCSK9. Further, despite the modest sample size, we identify one homozygote for a known pathogenic variant (ABCG8, p. Gly574Arg, global MAF = 4.49E-05) associated with Sitosterolemia 2. Finally, calculation of polygenic risk scores found that individuals with 'definite or probable' FH have a significantly higher LDL-C SNP score than 'unlikely' individuals (p = 0.0003), demonstrating its utility in Arab populations.

CONCLUSION

We design and implement a standardized approach to phenotyping a population biobank for FH risk followed by systematically identifying known variants and assessing putative novel variants contributing to FH burden in Qatar. Our results motivate similar studies in population-level biobanks - especially those with globally under-represented ancestries - and highlight the importance of genetic screening programs for early detection and management of individuals with high FH risk in health systems.

Premature coronary artery disease, risk factors, clinical presentation, angiography and interventions: Hospital based registry

BACKGROUND & AIMS

Premature coronary artery disease (CAD) is endemic in India. We performed a study to identify risk factors, clinical presentation, angiographic findings and interventions in premature CAD.

METHODS

Successive patients who underwent percutaneous intervention (PCI) were enrolled from January 2018 to June 2021. Premature CAD was defined as women 45-59 y and men 40-54 y and very premature as women <45 y and men <40 y. Descriptive statistics are presented. Univariate odds ratio (OR) and 95% confidence intervals (95%CI) were calculated to identify differences in various groups.

RESULTS

4672 patients (women 936, men 3736) were enrolled. Premature CAD was in 1238 (26.5%; women 31.9%; men 25.1%) and very premature in 212 (4.5%; women 6.5%, men 4.0%). In premature and very premature vs non-premature CAD, OR (95%CI) for high cholesterol ≥200 mg/dl [women 1.52(1.03-2.25) and 1.59(0.79-3.20); men 1.73(1.38-2.17) and 1.92(1.22-3.03)], non-HDL cholesterol ≥130 mg/dl [women 1.84(1.35-2.52) and 1.32(0.72-2.42); men 1.69(1.43-1.90) and 1.67(1.17-2.34)], LDL cholesterol [men 1.10(0.95-1.25) and 1.04(0.77-1.41)], and tobacco [women 1.40(0.84-2.35) and 2.14(0.95-4.82); men 1.63(1.34-1.98) and 1.27(0.81-1.97)] were higher while hypertension, diabetes and chronic kidney disease were more in non-premature(p < 0.05). Presentation as STEMI was marginally more in women with premature [1.13(0.85-1.51)] and very premature [1.29(0.75-2.22)] CAD and was significantly higher in men [1.35(1.16-1.56) and 1.79(1.29-2.49)]. Location and extent of CAD were not different.

CONCLUSIONS

In India, a third of CAD patients presenting for coronary intervention have premature disease. Important risk factors are high total and non-HDL cholesterol and tobacco (men) with greater presentation as STEMI. Extent and type of CAD are similar to non-premature CAD indicating severe disease.

Developing a Hybrid Risk Assessment Tool for Familial Hypercholesterolemia: A Machine Learning Study of Chinese Arteriosclerotic Cardiovascular Disease Patients

Background

Familial hypercholesterolemia (FH) is an autosomal-dominant genetic disorder with a high risk of premature arteriosclerotic cardiovascular disease (ASCVD). There are many alternative risk assessment tools, for example, DLCN, although their sensitivity and specificity vary among specific populations. We aimed to assess the risk discovery performance of a hybrid model consisting of existing FH risk assessment tools and machine learning (ML) methods, based on the Chinese patients with ASCVD.

Materials and Methods

In total, 5,597 primary patients with ASCVD were assessed for FH risk using 11 tools. The three best performing tools were hybridized through a voting strategy. ML models were set according to hybrid results to create a hybrid FH risk assessment tool (HFHRAT). PDP and ICE were adopted to interpret black box features.

Results

After hybridizing the mDLCN, Taiwan criteria, and DLCN, the HFHRAT was taken as a stacking ensemble method (AUC_class[94.85 ± 0.47], AUC_prob[98.66 ± 0.27]). The interpretation of HFHRAT suggests that patients aged <75 years with LDL-c >4 mmol/L were more likely to be at risk of developing FH.

Conclusion

The HFHRAT has provided a median of the three tools, which could reduce the false-negative rate associated with existing tools and prevent the development of atherosclerosis. The hybrid tool could satisfy the need for a risk assessment tool for specific populations.

Eating Habits in Patients with Familial Hypercholesterolemia from North-Eastern Romania

(1) Background: Familial hypercholesterolemia (FH) is a genetic autosomal dominant disorder characterized by elevated levels of low-density lipoprotein cholesterol (LDL) that develops deposits of lipids in the arterial wall. Since it is underdiagnosed and undertreated, the disease has a high risk of premature cardiovascular disease and death. Patients are not always aware of the changes they should make in their diet. Thus, our study aimed to evaluate through a food frequency questionnaire their eating habits. (2) Methods: We included 70 patients with FH and 20 subjects in a control group that were evaluated through a physical examination and blood tests. They also completed a food frequency questionnaire. (3) Results: Throughout our study, we observed several aspects: regardless of age, patients with FH had higher carbohydrate intakes compared to the control group; from the same group, a positive correlation was observed between salami intake and the levels of glucose and glycated hemoglobin. Moreover, the sour cream preference was associated with higher liver function tests. In the control group, we observed a higher intake of pasta and fast food and fewer fruit portions. (4) Conclusions: As far as we know, this is the first study from Romania that evaluated the eating habits of patients diagnosed with FH. Our study reveals that, although patients with FH avoid junk food, they still have a high intake of carbohydrates when compared to the control group. Further research is needed in order to get a comprehensive nutritional evaluation of these patients.

The Prevalence and Genetic Spectrum of Familial Hypercholesterolemia in Qatar Based on Whole Genome Sequencing of 14,000 Subjects

Familial hypercholesterolemia (FH) is an inherited disease characterized by reduced efficiency of low-density lipoprotein-cholesterol (LDL-C) removal from the blood and, consequently, an increased risk of life-threatening early cardiovascular complications. In Qatar, the prevalence of FH has not been determined and the disease, as in many countries, is largely underdiagnosed. In this study, we combined whole-genome sequencing data from the Qatar Genome Program with deep phenotype data from Qatar Biobank for 14,056 subjects to determine the genetic spectrum and estimate the prevalence of FH in Qatar. We used the Dutch Lipid Clinic Network (DLCN) as a diagnostic tool and scrutinized 11 FH-related genes for known pathogenic and possibly pathogenic mutations. Results revealed an estimated prevalence of 0.8% (1:125) for definite/probable cases of FH in the Qatari population. We detected 16 known pathogenic/likely pathogenic mutations in LDLR and one in PCSK9; all in a heterozygous state with high penetrance. The most common mutation was rs1064793799 (c.313+3A >C) followed by rs771019366 (p.Asp90Gly); both in LDLR. In addition, we identified 18 highly penetrant possibly pathogenic variants, of which 5 were Qatari-specific, in LDLR, APOB, PCSK9 and APOE, which are predicted to be among the top 1% most deleterious mutations in the human genome but further validations are required to confirm their pathogenicity. We did not detect any homozygous FH or autosomal recessive mutations in our study cohort. This pioneering study provides a reliable estimate of FH prevalence in Qatar based on a significantly large population-based cohort, whilst uncovering the spectrum of genetic variants associated with FH.

APOE Molecular Spectrum in a French Cohort with Primary Dyslipidemia

Primary hypercholesterolemia is characterized by elevated LDL-cholesterol (LDL-C) levels isolated in autosomal dominant hypercholesterolemia (ADH) or associated with elevated triglyceride levels in familial combined hyperlipidemia (FCHL). Rare APOE variants are known in ADH and FCHL. We explored the APOE molecular spectrum in a French ADH/FCHL cohort of 5743 unrelated probands. The sequencing of LDLR, PCSK9, APOB, and APOE revealed 76 carriers of a rare APOE variant, with no mutation in LDLR, PCSK9, or APOB. Among the 31 APOE variants identified here, 15 are described in ADH, 10 in FCHL, and 6 in both probands. Five were previously reported with dyslipidemia and 26 are novel, including 12 missense, 5 synonymous, 2 intronic, and 7 variants in regulatory regions. Sixteen variants were predicted as pathogenic or likely pathogenic, and their carriers had significantly lower polygenic risk scores (wPRS) than carriers of predicted benign variants. We observed no correlation between LDL-C levels and wPRS, suggesting a major effect of APOE variants. Carriers of p.Leu167del were associated with a severe phenotype. The analysis of 11 probands suggests that carriers of an APOE variant respond better to statins than carriers of a LDLR mutation. Altogether, we show that the APOE variants account for a significant contribution to ADH and FCHL.

Clinical decision support for familial hypercholesterolemia (CDS-FH): Rationale and design of a cluster randomized trial in primary care

BACKGROUND

Familial hypercholesterolemia (FH) is an underdiagnosed and undertreated genetic disorder with high risk of premature atherosclerotic cardiovascular disease and death. Clinical decision support (CDS) systems have the potential to aid in the identification and management of patients with FH. Prior studies using computer-based systems to screen patients for FH have shown promising results, but there has been no randomized controlled trial conducted. The aim of the current cluster randomized study is to evaluate if a CDS can increase the identification of FH.

METHODS

We have developed a CDS integrated in the electronic health records that will be activated in patients with elevated cholesterol levels (total cholesterol >8 mmol/L or low-density lipoprotein-cholesterol >5.5 mmol/L, adjusted for age, ongoing lipid lowering therapy and presence of premature coronary artery disease) at increased risk for FH. When activated, the CDS will urge the physician to send an automatically generated referral to the local lipid clinic for further evaluation. To evaluate the effects of the CDS, all primary care clinics will be cluster randomized 1:1 to either CDS intervention or standard care in a Swedish region with almost 500,000 inhabitants. The primary endpoint will be the number of patients diagnosed with FH at 30 months. Resource use and long-term health consequences will be estimated to assess the cost-effectiveness of the intervention.

CONCLUSION

Despite increasing awareness of FH, the condition remains underdiagnosed and undertreated. The present study will investigate whether a CDS can increase the number of patients being diagnosed with FH.

Whole Exome/Genome Sequencing Joint Analysis of a Family with Oligogenic Familial Hypercholesterolemia

Autosomal Dominant Hypercholesterolemia (ADH) is a genetic disorder caused by pathogenic variants in LDLR, APOB, PCSK9 and APOE genes. We sought to identify new candidate genes responsible for the ADH phenotype in patients without pathogenic variants in the known ADH-causing genes by focusing on a French family with affected and non-affected members who presented a high ADH polygenic risk score (wPRS). Linkage analysis, whole exome and whole genome sequencing resulted in the identification of variants p.(Pro398Ala) in CYP7A1, p.(Val1382Phe) in LRP6 and p.(Ser202His) in LDLRAP1. A total of 6 other variants were identified in 6 of 160 unrelated ADH probands: p.(Ala13Val) and p.(Aps347Asn) in CYP7A1; p.(Tyr972Cys), p.(Thr1479Ile) and p.(Ser1612Phe) in LRP6; and p.(Ser202LeufsTer19) in LDLRAP1. All six probands presented a moderate wPRS. Serum analyses of carriers of the p.(Pro398Ala) variant in CYP7A1 showed no differences in the synthesis of bile acids compared to the serums of non-carriers. Functional studies of the four LRP6 mutants in HEK293T cells resulted in contradictory results excluding a major effect of each variant alone. Within the family, none of the heterozygous for only the LDLRAP1 p.(Ser202His) variant presented ADH. Altogether, each variant individually does not result in elevated LDL-C; however, the oligogenic combination of two or three variants reveals the ADH phenotype.

Genetic Polymorphisms in a Familial Hypercholesterolemia Population from North-Eastern Europe

(1) Background: Familial hypercholesterolemia (FH) is one of the most prevalent inherited metabolic disorders. The purpose of the study was to investigate the role in cardiovascular disease (CVD) of PAI-1, ACE, ApoB-100, MTHFR A1298C, and C677T. (2) Methods: From a group of 1499 patients, we included 52 patients diagnosed with FH phenotype and 17 patients in a control group. (3) Results: Most of the FH patients had multiple comorbidities compared to the control group, such as atherosclerosis (48.1% vs. 17.6%), atherosclerotic cardiovascular disease (ASCVD 32.7% vs. 11.8%), and metabolic syndrome (MetS, 40.4% vs. 11.8%). In total, 66.7% of the FH patients had PAI-1 4G/5G genotype and MetS. Between 4G/5G and 4G/4G, a statistically significant difference was observed (p = 0.013). FH patients with ApoB R3500Q polymorphism were correlated with ASCVD (p = 0.031). Both MTHFR C677T and A1298C polymorphisms had a significant correlation with gender, alcohol consumption, and smoking status. ACE polymorphism was associated with ATS in FH patients, statistically significant differences being observed between heterozygous and homozygous D genotype (p = 0.036) as well as between heterozygous and homozygous I genotype (p = 0.021). (4) Conclusions: A link between these polymorphisms was demonstrated in the FH group for ATS, ASCVD, and MetS.

Low Detection Rates of Genetic FH in Cohort of Patients With Severe Hypercholesterolemia in the United Arabic Emirates

Background: Programs to screen for Familial hypercholesterolemia (FH) are conducted worldwide. In Western societies, these programs have been shown to be cost-effective with hit/detection rates of 1 in 217-250. Thus far, there is no published data on genetic FH in the Gulf region. Using United Arab Emirates as a proxy for the Gulf region, we assessed the prevalence of genetically confirmed FH in the Emirati population sample. Materials and Methods: We recruited 229 patients with LDL-C >95^th percentile and employed a customized next generation sequencing pipeline to screen canonical FH genes (LDLR, APOB, PCSK9, LDLRAP1). Results: Participants were characterized by mean total cholesterol and low-density lipoprotein cholesterol (LDL-c) of 6.3 ± 1.1 and 4.7 ± 1.1 mmol/L respectively. Ninety-six percent of the participants were using lipid-lowering medication with mean corrected LDL-c values of 10.0 ± 3.0 mmol/L 15 out of 229 participants were found to suffer from genetically confirmed FH. Carriers of causal genetic variants for FH had higher on-treatment LDL-c compared to those without causal variants (5.7 ± 1.5 vs 4.7 ± 1.0; p = 3.7E-04). The groups did not differ regarding high-density lipoprotein cholesterol, triglycerides, body mass index, blood pressure, glucose, and glycated haemoglobin. Conclusion: This study reveals a low 7% prevalence of genetic FH in Emiratis with marked hypercholesterolemia as determined by correcting LDL-c for the use of lipid-lowering treatment. The portfolio of mutations identified is, to a large extent, unique and includes gene duplications. Our findings warrant further studies into origins of hypercholesterolemia in these patients. This is further supported by the fact that these patients are also characterized by high prevalence of type 2 diabetes (42% in the current study cohort) which already puts them at an increased risk of atherosclerotic cardiovascular disease. These results may also be useful in public health initiatives for FH cascade screening programs in the UAE and maybe the Gulf region.

Cascade testing for elevated lipoprotein(a) in relatives of probands with familial hypercholesterolaemia and elevated lipoprotein(a)

BACKGROUND AND AIMS

Familial hypercholesterolaemia (FH) and elevated plasma lipoprotein(a) [Lp(a)] are inherited conditions independently associated with atherosclerotic cardiovascular disease. This study investigated the detection of new cases of elevated Lp(a) during cascade testing of relatives of probands with a definite diagnosis of FH and elevated Lp(a) (≥50 mg/dL).

METHODS

Relatives from 62 adult probands were tested for FH genetically and for elevated Lp(a) using an immunoassay. The prevalence and yield of new cases of FH with or without elevated Lp(a) among relatives and the association between the detection of elevated Lp(a) and the Lp(a) concentration of the probands were assessed.

RESULTS

Among 162 relatives tested (136 adults and 26 children), the prevalence of FH and elevated Lp(a) was 60.5% and 41.4%, respectively: FH alone was detected in 31.5%, elevated Lp(a) alone in 12.3%, FH with elevated Lp(a) in 29.0%, and neither disorder in 27.2% of the relatives. Cascade testing detected a new case of FH, elevated Lp(a) and FH with elevated Lp(a) for every 1.5, 2.1 and 3.0 relatives tested, respectively. The proportion of relatives detected with elevated Lp(a) was significantly higher when tested from probands with Lp(a) ≥100 mg/dL compared with those from probands with Lp(a) between 50 and 99 mg/dL (53% vs 34%, p = 0.018). The concordance between the detection of FH and elevated Lp(a) was 56.2% (kappa statistic 0.154), indicating a poor agreement.

CONCLUSIONS

A dual approach to cascade testing families for FH and high Lp(a) from appropriate probands can effectively identify not only new cases of FH, but also new cases of elevated Lp(a) with or without FH. The findings accord with the co-dominant and independent heritability of FH and Lp(a).

Genetic testing for familial hypercholesterolemia-past, present, and future

In the early 1980s, the Nobel Prize winning cellular and molecular work of Mike Brown and Joe Goldstein led to the identification of the LDL receptor gene as the first gene where mutations cause the familial hypercholesterolemia (FH) phenotype. We now know that autosomal dominant monogenic FH can be caused by pathogenic variants of three additional genes (APOB/PCSK9/APOE) and that the plasma LDL-C concentration and risk of premature coronary heart disease differs according to the specific locus and associated molecular cause. It is now possible to use next-generation sequencing to sequence all exons of all four genes, processing 96 patient samples in one sequencing run, increasing the speed of test results, and reducing costs. This has resulted in the identification of not only many novel FH-causing variants but also some variants of unknown significance, which require further evidence to classify as pathogenic or benign. The identification of the FH-causing variant in an index case can be used as an unambiguous and rapid test for other family members. An FH-causing variant can be found in 20-40% of patients with the FH phenotype, and we now appreciate that in the majority of patients without a monogenic cause, a polygenic etiology for their phenotype is highly likely. Compared with those with a monogenic cause, these patients have significantly lower risk of future coronary heart disease. The use of these molecular genetic diagnostic methods in the characterization of FH is a prime example of the utility of precision or personalized medicine.

Strategies for screening for familial hypercholesterolaemia in primary care and other community settings

BACKGROUND

Familial hypercholesterolaemia is a common inherited condition that is associated with premature cardiovascular disease. The increased cardiovascular morbidity and mortality, resulting from high levels of cholesterol since birth, can be prevented by starting lipid-lowering therapy. However, the majority of patients in the UK and worldwide remain undiagnosed. Established diagnostic criteria in current clinical practice are the Simon-Broome and Dutch Lipid Clinical network criteria and patients are classified as having probable, possible or definite familial hypercholesterolaemia.

OBJECTIVES

To assess the effectiveness of healthcare interventions strategies to systematically improve identification of familial hypercholesterolaemia in primary care and other community settings compared to usual care (incidental approaches to identify familial hypercholesterolaemia in primary care and other community settings).

SEARCH METHODS

We searched the Cochrane Inborn Errors of Metabolism Trials Register. Date of last search: 13 September 2021. We also searched databases (Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, PubMed, Embase, CINAHL, Web of Science, and SCOPUS) as well as handsearching relevant conference proceedings, reference lists of included articles, and the grey literature. Date of last searches: 05 March 2020.  SELECTION CRITERIA: As per the Effective Practice and Organisation of Care (EPOC) Group guidelines, we planned to include randomised controlled trials (RCTs), cluster-RCTs and non-randomised studies of interventions (NRSI). Eligible NRSI were non-randomised controlled trials, prospective cohort studies, controlled before-and-after studies, and interrupted-time-series studies. We planned to selected studies with healthcare interventions strategies that aimed to systematically identify people with possible or definite clinical familial hypercholesterolaemia, in primary care and other community settings. These strategies would be compared with usual care or no intervention. We considered participants of any age from the general population who access primary care and other community settings.

DATA COLLECTION AND ANALYSIS

Two authors planned to independently select studies according to the inclusion criteria, to extract data and assess for risk of bias and the certainty of the evidence (according to the GRADE criteria). We contacted corresponding study authors in order to obtain further information for all the studies considered in the review.

MAIN RESULTS

No eligible RCTs or NRSIs were identified for inclusion, however, we excluded 28 studies.

AUTHORS' CONCLUSIONS

Currently, there are no RCTs or controlled NRSI evidence to determine the most appropriate healthcare strategy to systematically identify possible or definite clinical familial hypercholesterolaemia in primary care or other community settings. Uncontrolled before-and-after studies were identified, but were not eligible for inclusion. Further studies assessing healthcare strategies of systematic identification of familial hypercholesterolaemia need to be conducted with diagnosis confirmed by genetic testing or validated through clinical phenotype (or both).

Limited-Variant Screening vs Comprehensive Genetic Testing for Familial Hypercholesterolemia Diagnosis

Question

How many clinically significant variants for familial hypercholesterolemia would be missed by limited-variant screening conducted on microarrays?

Findings

In this cross-sectional review of comprehensive genetic test results for individuals with indications for familial hypercholesterolemia, a limited-variant screen was found to have a significantly lower detection rate (8.4%) than the comprehensive diagnostic test (27%).

Meaning

The results of this study suggest that clinically significant findings for familial hypercholesterolemia would be missed for two-thirds of affected individuals if limited-variant screening was used.

Importance

Familial hypercholesterolemia (FH) is the most common inherited cardiovascular disease and carries significant morbidity and mortality risks. Genetic testing can identify affected individuals, but some array-based assays screen only a small subset of known pathogenic variants.

Objective

To identify the number of clinically significant variants associated with FH that would be missed by an array-based, limited-variant screen when compared with next-generation sequencing (NGS)–based comprehensive testing.

Design, Setting, and Participants

This cross-sectional study compared comprehensive genetic test results for clinically significant variants associated with FH with results for a subset of 24 variants screened by a limited-variant array. Data were deidentified next-generation sequencing results from indication-based or proactive gene panels. Individuals receiving next-generation sequencing–based genetic testing, either for an FH indication between November 2015 and June 2020 or as proactive health screening between February 2016 and June 2020 were included. Ancestry was reported by clinicians who could select from preset options or enter free text on the test requisition form.

Main Outcomes and Measures

Number of pathogenic or likely pathogenic (P/LP) variants identified.

Results

This study included 4563 individuals who were referred for FH diagnostic testing and 6482 individuals who received next-generation sequencing of FH-associated genes as part of a proactive genetic test. Among individuals in the indication cohort, the median (interquartile range) age at testing was 49 (32-61) years, 55.4% (2528 of 4563) were female, and 63.6% (2902 of 4563) were self-reported White/Caucasian. In the indication cohort, the positive detection rate would have been 8.4% (382 of 4563) for a limited-variant screen compared with the 27.0% (1230 of 4563) observed with the next-generation sequencing–based comprehensive test. As a result, 68.9% (848 of 1230) of individuals with a P/LP finding in an FH-associated gene would have been missed by the limited screen. The potential for missed findings in the indication cohort varied by ancestry; among individuals with a P/LP finding, 93.7% (59 of 63) of self-reported Black/African American individuals and 84.7% (122 of 144) of Hispanic individuals would have been missed by the limited-variant screen, compared with 33.3% (4 of 12) of Ashkenazi Jewish individuals. In the proactive cohort, the prevalence of clinically significant FH variants was approximately 1:191 per the comprehensive test, and 61.8% (21 of 34) of individuals with an FH-associated P/LP finding would have been missed by a limited-variant screen.

Conclusions and Relevance

Limited-variant screens may falsely reassure the majority of individuals at risk for FH that they do not carry a disease-causing variant, especially individuals of self-reported Black/African American and Hispanic ancestry.

A service evaluation: impact of nurse-led regional familial hypercholesterolaemia service on a hospital adult lipid clinic

The authors evaluated the impact of genetic screening for familial hypercholesterolaemia (FH) in a lipid clinic cohort of patients with definite and possible FH as defined by the Simon Broome Register (SBR) criteria.

METHODS

Patients with a lipid clinic diagnosis of definite and possible FH based on the SBR criteria were referred to a nurse-led regional service for FH genetic testing.

FINDINGS

140 patients were referred for genetic testing. Six had SBR-definite FH due to the presence of tendon xanthomata and 134 had SBR-possible FH. A monogenic FH mutation was detected in all six patients (100%) with SBR-definite FH and in 34 (25%) of patients with possible FH.

CONCLUSION

The appropriate use of molecular genetics in a lipid clinic will greatly facilitate the management of hyperlipidaemia and cardiovascular risk since the management of FH patients (National Institute for Health and Care Excellence (NICE) Clinical Guideline 71) is different from non-FH patients (NICE Clinical Guideline 181).

Feasibility and cost of FH cascade screening in Belgium (BEL-CASCADE) including a novel rapid rule-out strategy

BACKGROUND

Familial hypercholesterolaemia (FH) is underdiagnosed in most countries. We report our first experience from a national pilot project of cascade screening in relatives of FH patients.

METHODOLOGY

Participating specialists recruited consecutive index patients (IP) with Dutch Lipid Clinic Network (DLCN) score ≥6. After informed consent, the relatives were visited by the nurses to collect relevant clinical data and perform blood sampling for lipid profile measurement. FH diagnosis in the relatives was based on the DLCN and/or MEDPED FH (Make-Early-Diagnosis-to-Prevent-Early-Deaths-in-FH) criteria.

RESULTS

In a period of 18 months, a total of 127 IP (90 with definite FH and 37 with probable FH) were enrolled in 15 centres. Out of the 270 relatives visited by the nurses, 105 were suspected of having FH: 31 with DCLN score >8, 33 with DLCN score 5-8 and 41 with MEDPED FH criteria. In a post-hoc analysis, another set of MEDPED FH criteria established in the Netherlands and adapted to Belgium allowed to detect FH in 51 additional relatives.

CONCLUSION

In a country with no national FH screening program, our pilot project demonstrated that implementing a simple phenotypical FH cascade screening strategy using the collaboration of motivated specialists and two nurses, allowed to diagnose FH in 127 index patients and an additional 105 of their relatives over the two-year period. Newly developed MEDPED FH cut-offs, easily applicable by a nurse with a single blood sample, might further improve the sensitivity of detecting FH within families.

Genetic basis of hypercholesterolemia in adults

We investigated monogenic and polygenic causes of hypercholesterolemia in a population-based cohort, excluding secondary hypercholesterolemia, and using an established framework to identify pathogenic variants. We studied 1682 individuals (50.2 ± 8.6 years, 41.3% males) from southeast Minnesota with primary hypercholesterolemia (low-density lipoprotein cholesterol (LDL-C) ≥155 mg/dl in the absence of identifiable secondary causes). Familial hypercholesterolemia (FH) phenotype was defined as a Dutch Lipid Clinic Network (DLCN) score ≥6. Participants underwent sequencing of LDLR, APOB, and PCSK9, and genotyping of 12 LDL-C-associated single-nucleotide variants to construct a polygenic score (PGS) for LDL-C. The presence of a pathogenic/likely pathogenic variant was considered monogenic etiology and a PGS ≥90th percentile was considered polygenic etiology. The mean LDL-C level was 187.3 ± 32.3 mg/dl and phenotypic FH was present in 8.4% of the cohort. An identifiable genetic etiology was present in 17.1% individuals (monogenic in 1.5% and polygenic in 15.6%). Phenotypic and genetic FH showed poor overlap. Only 26% of those who met the clinical criteria of FH had an identifiable genetic etiology and of those with an identifiable genetic etiology only 12.9% met clinical criteria for FH. Genetic factors explained 7.4% of the variance in LDL-C. In conclusion, in adults with primary hypercholesterolemia, 17.1% had an identifiable genetic etiology and the overlap between phenotypic and genetic FH was modest.

Closing the gap: Identification and management of familial hypercholesterolemia in an integrated healthcare delivery system

BACKGROUND

Familial hypercholesterolemia (FH) is an autosomal dominant genetic disorder that causes markedly elevated risk for early onset coronary artery disease. Despite availability of effective therapy, only 5-10% of affected individuals worldwide are diagnosed.

OBJECTIVE

To develop and evaluate a novel approach for identifying and managing patients with FH in a large integrated health system with a diverse patient population, using inexpensive methods.

METHODS

Using Make Early Diagnosis/Prevent Early Death (MEDPED) criteria, we created a method for identifying patients at high risk for FH within the Kaiser Permanente Northern California electronic medical record. This led to a pragmatic workflow for contacting patients, establishing a diagnosis in a dedicated FH clinic, and initiating management. We prospectively collected data on the first 100 patients to assess implementation effectiveness.

RESULTS

Ninety-three (93.0%, 95%CI: 86.1%-97.1%) of the first 100 evaluated patients were diagnosed with FH (median age = 38 years) of whom only 5% were previously recognized; 48% were taking no lipid-lowering therapy, and 7% had acute coronary symptoms. 82 underwent successful genetic testing of whom 55 (67.1%; 95%CI: 55.8%-77.1%) had a pathogenic mutation. Following clinic evaluation, 83 of 85 (97.6%) medication-eligible patients were prescribed combination lipid-lowering therapy. 20 family members in the healthcare system were diagnosed with FH through cascade testing.

CONCLUSIONS

This novel approach was effective for identifying and managing patients with undiagnosed FH. Care gaps in providing appropriate lipid-lowering therapy were successfully addressed. Further development and dissemination of integrated approaches to FH care are warranted.

Familial Hypercholesterolemia: Update and Review

Knowledge of epidemiology, genetic etiopathogenesis, diagnostic criteria, and management of familial hypercholesterolemia have increased in the last two decades. Several population studies have shown that familial hypercholesterolemia is more frequent than previously thought, making this entity the most common metabolic disease with monogenic inheritence in the world. Identification of causal heterozygous pathogenic variants in LDLR, APOB, and PCSK9 genes have increased diagnostic accuracy of classical criteria (extreme hypercholesterolemia, personal / family history of premature coronary artery disease or other cardiovascular disease). Genetic screening has been recently introduced in many European countries to detect patients with familial hypercholesterolemia, mainly affected pediatric subjects, asymptomatic or those at the beggining of their disease, with the purpose of increasing surveillance and avoiding complications such as cardiovascular diseases. Cholesterol-lowering drugs should be started as soon as the diagnosis is made. Various combinations between drugs can be used when the goal is not achieved. New therapies, including small interference ribonucleic acids (siRNA) are being tested in different clinical trials.

PCSK9 Inhibitors in a German Single-Center Clinical Practice: Real-World Treatment of Patients at High Cardiovascular Risk Over 68 Weeks

Aims

Several the use of proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) for patients at high/very high cardiovascular risk who are inadequately treated with maximally tolerated lipid-lowering therapies (LLTs).

Objectives

We assessed the effectiveness and safety of the PCSK9i alirocumab and evolocumab in a single-center clinical practice for up to 68 weeks.

Methods

In this prospective, open-label study conducted in Germany, 635 enrolled patients were treated with alirocumab [75 or 150 mg every 2 weeks (Q2W)] or evolocumab (140 mg Q2W) according to European Society of Cardiology/European Atherosclerosis Society guidelines (low-density lipoprotein cholesterol [LDL-C] > 1.81/2.59 mmol/L (70/100 mg/dL), depending on cardiovascular risk]. Investigators were able to adjust LLTs, including PCSK9i, according to their own clinical judgment. The primary effectiveness endpoint was LDL-C reduction from baseline to week 68.

Results

At baseline, approximately 50% of patients were statin intolerant, and approximately 90% reported a history of cardiovascular disease. LDL-C reductions remained generally unchanged from weeks 4 to 68 in each treatment group. At week 68, LDL-C mean percentage changes from baseline were − 41.7% (alirocumab 75 mg Q2W), − 53.7% (alirocumab 150 mg Q2W), and − 54.1% (evolocumab 140 mg Q2W). LDL-C reduction was 7.1% greater in patients receiving statins than in those not receiving statins because of statin intolerance (P < 0.0001). PCSK9i consistently improved levels of other lipoproteins throughout. Overall, 47.1% of patients reported adverse events at week 68.

Conclusions

Consistent with clinical trial findings, alirocumab and evolocumab improved lipid levels in a real-world setting in patients with high baseline LDL-C levels despite receiving maximally tolerated LLTs. PCSK9i were generally well-tolerated.

Electronic supplementary material

The online version of this article (10.1007/s40256-020-00411-3) contains supplementary material, which is available to authorized users.

Targeted Genetic Analysis in a Chinese Cohort of 208 Patients Related to Familial Hypercholesterolemia

AIM

Familial hypercholesterolemia (FH) is the most commonly encountered genetic condition that predisposes individuals to severe autosomal dominant lipid metabolism dysfunction. Although more than 75% of the European population has been scrutinized for FH-causing mutations, the genetic diagnosis proportion among Chinese people remains very low (less than 0.5%). The aim of this study was to identify genetic mutations and help make a precise diagnosis in Chinese FH patients.

METHODS

We designed a gene panel containing 20 genes responsible for FH and tested 208 unrelated Chinese possible/probable or definite FH probands. In addition, we called LDLR copy number variation (CNVs) with the panel data by panelcn.MOPS, and multiple ligation-dependent probe amplification (MLPA) was used to search for CNVs in LDLR, APOB, and PCSK9.

RESULTS

A total of 79 probands (38.0%) tested positive for a (likely) pathogenic mutation, most of which were LDLR mutations, and three LDLR CNVs called from the panel data were all successfully confirmed by MLPA analysis. In total, 48 different mutations were identified, including 45 LDLR mutations, 1 APOB mutation, 1 ABCG5 mutation, and 1 APOE mutation. Among them, the five most frequent mutations (LDLR c.1879G＞A, c.1747C＞T, c.313＋1G＞A, c.400T＞C, and APOB c.10579C＞T) were detected. Moreover, we also found that patients with LDLR variants of CNVs and splicing and nonsense had increased low-density lipoprotein cholesterol levels when compared with those who carried missense variants.

CONCLUSIONS

The spectrum of FH-causing mutations in the Chinese population is refined and expanded. Analyses of FH causal genes have been a great help in clinical diagnosis and have deep implications in disease treatment. These data can serve as a considerable dataset for next-generation sequencing analysis of the Chinese population with FH and contribute to the genetic diagnosis and counseling of FH patients.

How registers could enhance knowledge and characterization of genetic dyslipidaemias: The experience of the LIPIGEN in Italy and of other networks for familial hypercholesterolemia

Familial hypercholesterolemia (FH) is a common genetic disorder of lipid metabolism, still underdiagnosed and undertreated in the general population. Pathology registers could play a crucial role in the creation of a comprehensive and integrated global approach to cover all aspects of this disease. Systematic data collection of patients affected by FH has increased dramatically worldwide in the past few years. Moreover, results from registers already established for the longest time showed their potentialities in the implementation of the knowledge of FH, comparing country-specific approaches and providing real-world data about identification, management and treatment of FH individuals in the clinical practice. The potential fields of research through registers are related to the deepening of the genetic basis of disease, the study of genotype-phenotype correlation, the local adaption and implementation of diagnostic algorithms, the comparison of pharmacological approaches and treatment gaps in real-life clinical practice, the evaluation of specific subpopulations, and the identification of factors modifying cardiovascular disease risk. Registers could become also a valid resource for other rare dyslipidaemias, contributing towards the evidence-based enhancement in the worldwide care of uncommon diseases.

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.

Prevalence of Familial Hypercholesterolaemia in Acute Coronary Syndrome Patients in a Large Regional Coronary Care Unit

BACKGROUND

Familial hypercholesterolaemia (FH) is an under recognised cause of coronary artery disease, despite the proven reductions in risk with early detection and treatment.

METHODS

Data from 180 consecutive patients presenting to a large regional hospital with acute coronary syndrome were collected. Potential FH was assessed using the Dutch Lipid Clinic Network Criteria (DLCNC), and if patients were on statins, pre-treatment cholesterol was estimated according to a validated algorithm.

RESULTS

Ninety per cent (90%) of patients presented with non-ST elevation myocardial infarction (NSTEMI) or ST elevation myocardial infarction (STEMI). A total of 11 patients (6%) were classified as having phenotypic FH. The phenotypic FH cohort was younger (mean age 53.1 vs 62.0, p=0.011); and more likely to have documented ischaemic heart disease (63.6% vs 20.7%, p=0.001).

PHENOTYPIC FH PATIENTS

Familial hypercholesterolaemia patients had a higher rate of ezetimibe use (18.2% vs 2.4%, p=0.005), but fibrate use was not significantly different. Phenotypic FH patients also had higher levels of total cholesterol, corrected LDL and triglycerides, but no statistically significant difference in HDL levels compared with non-FH counterparts.

CONCLUSIONS

The prevalence of FH is relatively high among patients presenting with acute coronary syndromes. This has now been established in a regional Australian population, with similar prevalence to large European registries. This highlights the need for improved access to specialised services in regional and rural areas to reduce adverse cardiovascular (CV) outcomes.

The Gulf Familial Hypercholesterolemia Registry (Gulf FH): Design, Rationale and Preliminary Results

Aim:

To determine the prevalence, genetic characteristics, current management and outcomes of familial hypercholesterolaemia (FH) in the Gulf region.

Methods:

Adult (18-70 years) FH patients were recruited from 9 hospitals and centres across 5 Arabian Gulf countries. The study was divided into 4 phases and included patients from 3 different categories. In phase 1, suspected FH patients (category 1) were collected according to the lipid profile and clinical data obtained through hospital record systems. In phase 2, patients from category 2 (patients with a previous clinical diagnosis of FH) and category 1 were stratified into definitive, probable and possible FH according to the Dutch Lipid Clinic Network criteria. In phase 3, 500 patients with definitive and probable FH from categories 1 and 2 will undergo genetic testing for 4 common FH genes. In phase 4, these 500 patients with another 100 patients from category 3 (patients with previous genetic diagnosis of FH) will be followed for 1 year to evaluate clinical management and cardiovascular outcomes. The Gulf FH cohort was screened from a total of 34,366 patients attending out-patient clinics.

Results:

The final Gulf FH cohort consisted of 3,317 patients (mean age: 47±12 years, 54% females). The number of patients with definitive FH is 203. In this initial phase of the study, the prevalence of (probable and definite) FH is 1/232.

Conclusion:

The prevalence of FH in the adult population of the Arabian Gulf region is high. The Gulf FH registry, a first-of-a-kind multi-national study in the Middle East region, will help in improving underdiagnosis and undertreatment of FH in the region.

Non-HDL or LDL cholesterol in heterozygous familial hypercholesterolaemia: findings of the Simon Broome Register

PURPOSE OF REVIEW

The role of non-HDL-C in the identification and management of lipid disorders is not clearly defined, although UK guidelines recommend its wider use in assessing the need for lipid-lowering therapy and as a treatment target.

RECENT FINDINGS

We examined the implications of the use of non-HDL-C as opposed to LDL-C in 253 people with hypercholesterolaemia before treatment and 573 after treatment in whom fasting total serum cholesterol, HDL-C and LDL-C had been recorded and the diagnosis of heterozygous familial hypercholesterolemia (heFH) was investigated by genetic testing. The difference and the limits of agreement between non-HDL-C and LDL-C calculated using the Friedewald formula were assessed in those with and without heFH-causing mutations.

SUMMARY

There were 147 mutation-positive and 106 mutation-negative pretreatment participants and 395 mutation-positive and 178 mutation-negative patients receiving treatment. The difference between non-HDL-C and LDL-C pretreatment in mutation-positive people (mean LDL-C 7.73 mmol/l) was 0.67 mmol/l (95% CI 0.62-0.73) and posttreatment (mean LDL-C 4.71 mmol/l) was 0.62 mmol/l (95% CI 0.59-0.65) with wide limits of agreement of -0.02 to 1.37 and 0.07-1.18 mmol/l, respectively. Among patients with heterozygous familial hypercholesterolaemia, use of estimated LDL-C derived from non-HDL-C in place of calculated LDL-C may result in diagnostic misclassification and difficulty in assessing the true reduction in LDL-C with treatment, because of the wide inter-individual limits of agreement around the mean difference between non-HDL-C and LDL-C.

Coronary artery disease and the risk-associated LPA variants, rs3798220 and rs10455872, in patients with suspected familial hypercholesterolaemia

BACKGROUND

The rs3798220 and rs10455872 single nucleotide polymorphisms (SNPs) in LPA are associated with increased plasma concentrations of lipoprotein(a) [Lp(a)] and coronary artery disease (CAD).

METHODS

We investigated the association between rs3798220 and rs10455872 and prevalent CAD in 763 patients with suspected familial hypercholesterolaemia (FH). The rs3798220 and rs10455872 SNPs in LPA were detected using a SEQUENOM platform.

RESULTS

Both LPA SNPs were significantly associated with CAD, but only rs3798220 after adjustment for other risk factors (odds ratio [OR] 2.05; 95% confidence interval [CI] 1.02-4.12; p = 0.045), and neither after adjustment for Lp(a) concentrations. Both SNPs were positively and independently associated with increased Lp(a) (rs3798220: OR 1.27; 95% CI 0.96-1.57; p < 0.001. rs10455872: OR 1.41; 95% CI 1.24-1.58; p < 0.001). Plasma concentrations of Lp(a) were independently associated with prevalent CAD (OR 1.28; 95% CI 1.08-1.52, p = 0.005) after adjustment for LPA SNPs and other cardiovascular risk factors. While both the rs3798220 and rs10455872 SNPs were associated with Lp(a) concentrations and prevalent CAD in patients with suspected FH, this was not independent of Lp(a) concentration.

CONCLUSIONS

Quantification of Lp(a) is more likely to be useful than assessment of these Lp(a)-associated SNPs to augment CAD risk prediction.

Do reflex comments on laboratory reports alter patient management?

INTRODUCTION

Laboratory comments appended on clinical biochemistry reports are common in the UK. Although popular with clinicians and the public, there is little evidence that these comments influence the clinical management of patients.

METHODS

We provided reflex automated laboratory comments on all primary care lipid results including, if appropriate, recommendation of direct referral to the West Midlands Familial Hypercholesterolaemia service (WMFHS). Over a two-year period, the number GP referrals from the Wolverhampton City Clinical Commissioning Group (CCG) to the WMFHS were compared with four comparator CCGs of similar population size, who were not provided with reflex laboratory comments.

RESULTS

Over the study period, the WMFHS received more referrals from Wolverhampton GPs (241) than any other comparator CCG (range 8-65) and greater than the combined referrals (172) from all four comparator CCGs.

CONCLUSION

Targeted reflex laboratory comments may influence the clinical management of patients and may have a role in the identification of individuals with familial hypercholesterolaemia.