Diagnóstico y tratamiento de la hipercolesterolemia familiar en España: documento de consenso

Prevalence of severe hypercholesterolemia observed in different hospitals in Andalusia and Ceuta

Severe hypercholesterolaemia is a major cardiovascular risk factor. Early detection and treatment can reduce the incidence of cardiovascular disease. Given the high prevalence of hypercholesterolaemia in Andalusia, the development of a screening strategy for its detection in Primary Care may be an efficient measure.

OBJECTIVE

To identify patients in Primary Care with severe hypercholesterolaemia that may increase their cardiovascular risk by reviewing LDL-cholesterol results in computerised laboratory systems.

MATERIAL AND METHODS

Observational, retrospective, multi-centre study in 16 hospitals in Andalusia and Ceuta. Anonymous analytical data were acquired from the different laboratory computer systems for the year 2018, and exclusively from Macarena Hospital for the year 2019.

RESULTS

From a total of 1,969,035 determinations on≥18 years old, 2,791 patients (0.14%) were detected with LDL-cholesterol>250mg/dl and from a total of 2.327.211 determinations studied in children under 18 years old, 3,804 patients (0.16%) were detected with LDL-cholesterol>135mg/dL. The highest incidence of possible genetic hypercholesterolaemia in adults corresponded to the province of Seville with 23.6 cases/1,000 determinations, while in minors, the highest incidence corresponded to the province of Cadiz with 75 possible cases/1,000 determinations. A geographical triangle of greater prevalence is observed between the provinces of Seville, Huelva and Cadiz.

CONCLUSIONS

The development of a screening strategy using a computerised review of LDL-cholesterol in Primary Care detects a large number of subjects with severe hypercholesterolaemia that could benefit from an early intervention.

Phenotypic characterization and predictive analysis of p.Asp47Asn LDL receptor mutation associated with Familial Hypercholesterolemia in a Chilean population

BACKGROUND

Familial hypercholesterolemia (FH) is an inherited disorder mainly caused by mutations in the LDL receptor (LDL-R) and characterized by elevation of low-density lipoprotein cholesterol (LDL-C) levels and premature cardiovascular disease.

OBJECTIVE

In this study, we evaluated the clinical phenotype of the p.Asp47Asn, described as an uncertain pathogenic variant, and its effect on the structure of LDL-R and ligand interactions with apolipoproteins.

METHODS

27 children and adolescents with suspected FH diagnosis were recruited from a pediatric endocrinology outpatient clinic. Blood samples were collected after 12 h fasting for lipid profile analysis. DNA sequencing was performed for six FH-related genes by Ion Torrent PGM platform and copy number variation by MLPA. For index cases, a familial cascade screening was done restricted to the same mutation found in the index case. In silico analysis were developed to evaluate the binding capacity of LDL-R to apolipoproteins B100 and E.

RESULTS

Lipid profile in children and adolescents demonstrated higher LDL-C levels in p.Asp47Asn carriers compared to the wild type genotype. In silico analysis predicted a reduction in the binding capacity of the ligand-binding modules LA1-2 of p.Asp47Asn LDL-R for ApoB100 and ApoE, which was not produced by local structural changes or folding defects but as a consequence of a decreased apparent affinity for both apolipoproteins.

CONCLUSION

The clinical phenotype and the structural effects of p.Asp47Asn LDL-R mutation suggest that this variant associates to FH.

Reducing the Clinical and Public Health Burden of Familial Hypercholesterolemia: A Global Call to Action

Importance

Familial hypercholesterolemia (FH) is an underdiagnosed and undertreated genetic disorder that leads to premature morbidity and mortality due to atherosclerotic cardiovascular disease. Familial hypercholesterolemia affects 1 in 200 to 250 people around the world of every race and ethnicity. The lack of general awareness of FH among the public and medical community has resulted in only 10% of the FH population being diagnosed and adequately treated. The World Health Organization recognized FH as a public health priority in 1998 during a consultation meeting in Geneva, Switzerland. The World Health Organization report highlighted 11 recommendations to address FH worldwide, from diagnosis and treatment to family screening and education. Research since the 1998 report has increased understanding and awareness of FH, particularly in specialty areas, such as cardiology and lipidology. However, in the past 20 years, there has been little progress in implementing the 11 recommendations to prevent premature atherosclerotic cardiovascular disease in an entire generation of families with FH.

Observations

In 2018, the Familial Hypercholesterolemia Foundation and the World Heart Federation convened the international FH community to update the 11 recommendations. Two meetings were held: one at the 2018 FH Foundation Global Summit and the other during the 2018 World Congress of Cardiology and Cardiovascular Health. Each meeting served as a platform for the FH community to examine the original recommendations, assess the gaps, and provide commentary on the revised recommendations. The Global Call to Action on Familial Hypercholesterolemia thus represents individuals with FH, advocacy leaders, scientific experts, policy makers, and the original authors of the 1998 World Health Organization report. Attendees from 40 countries brought perspectives on FH from low-, middle-, and high-income regions. Tables listing country-specific government support for FH care, existing country-specific and international FH scientific statements and guidelines, country-specific and international FH registries, and known FH advocacy organizations around the world were created.

Conclusions and Relevance

By adopting the 9 updated public policy recommendations created for this document, covering awareness; advocacy; screening, testing, and diagnosis; treatment; family-based care; registries; research; and cost and value, individual countries have the opportunity to prevent atherosclerotic heart disease in their citizens carrying a gene associated with FH and, likely, all those with severe hypercholesterolemia as well.

Familial hypercholesterolemia: Experience in the Lipid Clinic of Alava

INTRODUCTION

Familial hypercholesterolaemia (FH) is the autosomal dominant genetic disorder most frequently associated with premature cardiovascular disease (CVD).

MATERIAL AND METHODS

A retrospective, observational study was conducted to determine the clinical characteristics, analytical parameters and cardiovascular risk factors of 133 patients with a genetically confirmed diagnosis of FH on follow-up in the Lipid Clinic of Alava.

RESULTS

CVD was observed in 8.30% of the patients (ischaemic heart disease in 100% of the cases). The LDL concentration goal was achieved in 40.6% (45.50% in primary prevention and 27.30% in secondary prevention). The large majority (81.80%) of patients with coronary heart disease (CHD) were male. The odds ratio (OR) of males having CHD compared to females is 4.97 (1.03-23.93, P=.03). The OR of developing CHD in patients with a family history of premature CVD is 6.86 (1.32-35.67, P=.02). A statistically significant association was found between smoking and the risk of CVD (P=.005), and also between having diabetes and the risk of CVD (P=0.0001). If the treatment with statins begins at older than 40 years, the OR of suffering CHD is 6.40 (1.53-26.5) (P=.009). The mean time from diagnosis to the cardiovascular event in the group of ex-smokers is 10.80±5.80 years, and in the non-smoking group it is 17.50±2.50 years (P=.011).

CONCLUSIONS

In our reference population with FH, it was found that there was an increased risk of suffering a cardiovascular event in male patients, with a family history of premature CVD, diabetics, and in those in whom lipid lowering treatment was started after 40 years of age.

Selection of individuals for genetic testing for familial hypercholesterolaemia: development and external validation of a prediction model for the presence of a mutation causing familial hypercholesterolaemia

Aims

Familial hypercholesterolaemia (FH) is an autosomal dominant disease that warrants early diagnosis to prevent premature cardiovascular disease (CVD). However, genetic testing to make a definite diagnosis is costly, and careful selection of eligible subjects is important. Unfortunately, accuracy of current diagnostic criteria is poor, especially in young individuals. We therefore developed and validated a model to predict the presence of an FH causing mutation in persons referred by general practitioners.

Methods and results

All participants in the Dutch FH screening programme from 1994 to 2014 were included in the development cohort. The validation cohort consisted of consecutive patients, suspected for FH, attending the outpatient lipid clinic in Saguenay (Quebec) from 1993 to 2014. Cross-sectional data were available on medical history, lipid profile, and DNA analysis. Multivariable logistic regression analysis was used for model development. The primary outcome was the presence of a deleterious FH mutation. The development cohort comprised 26 167 FH patients and 37 939 unaffected relatives. Our final model included age; sex; levels of low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, and triglycerides; history and age of CVD; use of statins; smoking; alcohol; and presence of hypertension. The area under the receiver operating characteristic curve (AUC) was 85.4% (95% CI: 85.0-85.9). The calibration slope was 1.02 (where 1.00 is optimal). In the validation cohort (1436 FH patients and 1767 unaffected persons), the AUC was 95.4% (95% CI: 94.7-96.1%) and the calibration slope 1.06.

Conclusion

Our model showed good discrimination and calibration. We specifically expect our model to be of added value for young persons set against current diagnostic criteria, since LDL-C and age are now used as continuous predictors. The equation will be available as an online calculator to estimate the probability of the presence of an FH mutation in individual patients. This tool might aid physicians in the decision for referral of patients for molecular testing.