Cardiac computed tomography imaging in familial hypercholesterolaemia: implications for therapy and clinical trials

Atherosclerosis severity in patients with familial hypercholesterolemia: The role of T and B lymphocytes

Background and aims

Familial hypercholesterolemia (FH) is characterized by lifelong exposure to high LDL-c concentrations and premature atherosclerotic cardiovascular disease; nevertheless, disease severity can be heterogeneous.We aimed at evaluating if the immune-inflammatory system could modulate atherosclerosis burden in FH.

Methods

From a cohort of subjects with confirmed FH (Dutch Lipid Clinic Network and genotype), 92 patients receiving high-intensity lipid-lowering therapy (statin ± ezetimibe) were included. The extension and severity of coronary atherosclerosis was assessed by standardized reporting systems (CAD-RADS) for coronary computed tomography angiography (CCTA) and coronary artery calcium (CAC) scores. Lipids, apolipoproteins, anti-oxLDL and anti-apolipoprotein B-D peptide (anti-ApoB-D) autoantibodies (IgM and IgG), lymphocytes subtypes, platelet, monocyte and endothelial microparticles (MP), IgM levels (circulating or produced by B1 cells) and cytokines in the supernatant of cultured cells were determined. Multiple linear regression models evaluated associations of these biomarkers with CAC and CAD-RADS scores.

Results

In univariate analysis CAC correlated with age, systolic blood pressure, TCD4+ cells, and titers of IgM anti-ApoB-D. In multiple linear regression [ANOVA F = 2.976; p = 0.024; R² = 0.082), CD4+T lymphocytes (B = 35.289; beta = 0.277; p = 0.010; 95%CI for B 8.727 to 61.851), was independently associated with CAC. CAD-RADS correlated with age, systolic blood pressure, titers of IgM anti-ApoB-D, and endothelial MP in univariate analysis. In multiple linear regression, [ANOVA F = 2.790; p = 0.032; R² = 0.119), only age (B = 0.027; beta = 0.234; p = 0.049; 95% CI for B 0.000 to 0.053) was independent predictor.

Conclusions

In subjects with FH, under high-intensity lipid-lowering therapy, age and CD4+T cells were associated to atherosclerosis burden.

Vascular access for lipid apheresis: a challenge in young children with homozygous familial hypercholesterolemia

Background

Homozygous familial hypercholesterolemia (hoFH) is a rare genetic disorder leading to extremely increased LDL-cholesterol (LDL-C), resulting in high cardiovascular risk in early childhood. Lipid apheresis (LA) is an effective treatment and should be started as early as possible to prevent premature cardiovascular events. As peripheral punctures in children can be challenging due to small vessels and anxiety, this study aimed to evaluate feasibility and safety of central venous catheters (CVCs) as vascular access for LA in young children with hoFH.

Methods

Retrospective analysis (2016-2019) on four children with hoFH aged 3-5 years, performing weekly or biweekly LA with a CVC.

Results

LDL-C decreased by> 60%. In three children, the use of a permanent CVC for 698, 595, and 411 days, respectively, avoided difficult peripheral access, without the occurrence of occlusion or thrombosis. Unfortunately, one child had recurrent CVC-related infections and needed an arteriovenous fistula from the age of 5. Although the mean dwell time per catheter was 212 days, there were, as expected, severe side effects of early catheter infections with sepsis and accidental self-removal. Starting LA at an early age improved or stabilized carotid intima-media thickness (IMT) in three children. However, IMT did increase in one child caused by intolerance to peripheral punctures and LA interruption.

Conclusions

Permanent CVCs are a viable temporary access choice for LA in young children with hoFH until peripheral venipuncture is practicable. The risk of CVC-related infections needs to be taken into account.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03192-7.

Clinical guidance on the contemporary use of proprotein convertase subtilisin/kexin type 9 monoclonal antibodies

There is now significant evidence for the benefits of lowering low-density lipoprotein cholesterol (LDL-c) to reduce the risk of atherosclerotic cardiovascular disease (ASCVD). Although statins are the most widely prescribed lipid-lowering therapy that effectively lower LDL-c, especially in combination with ezetimibe, some patients require adjunctive therapy to further lower LDL-c and mitigate attendant risk of ASCVD. The gap can be filled by proprotein convertase subtilisin/kexin type 9 (PCSK9) monoclonal antibodies whose use is currently supported by two recent cardiovascular outcome studies and new treatment guidelines. We provide an overview of extant studies investigating PCSK9 monoclonal antibodies in various patient populations, an update of the guidelines regarding their use and a case-based discussion.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Complex disease management of pregnant young patient with familial hypercholesterolaemia complicated by coronary artery disease and cerebrovascular disease

Inherited disorders of lipid metabolism may cause a heavy burden of cardiovascular disease early in life. Familial hypercholesterolaemia (FH) with abnormalities of LDL metabolism results in marked LDL elevations and accelerated, multivessel atherosclerosis presenting in teenage or young adulthood. We describe the case of a 33-year-old woman who presented with exertional angina in the setting of pregnancy who was found post-partum to have severe triple-vessel disease including left main disease on coronary angiography (Figs. 1 and 2). She was also noted to have a typical supravalvular "hourglass" [1] abnormality of the aortic root (Fig. 3), and heavy calcification of the proximal aorta precluding conventional aortic cross clamping and bypass surgery. After discussion with the multidisciplinary team, her disease was felt to be amenable to a beating-heart coronary bypass technique with an anaortic approach to minimise the possibility of cerebral embolism. Significant extracranial cerebrovascular disease, a major risk for cardiopulmonary bypass, reinforced the beating-heart technique. Her ongoing management has consisted of medical therapy with cessation of breast feeding, statins, ezetimibe, and introduction of PCSK9-inhibitor therapy. This case illustrates a number of the difficulties associated with management of widespread atherosclerotic disease associated with FH, in which an excellent outcome was achieved with the assistance of a multi-disciplinary team.

Defining severe familial hypercholesterolaemia and the implications for clinical management: a consensus statement from the International Atherosclerosis Society Severe Familial Hypercholesterolemia Panel

Familial hypercholesterolaemia is common in individuals who had a myocardial infarction at a young age. As many as one in 200 people could have heterozygous familial hypercholesterolaemia, and up to one in 300 000 individuals could be homozygous. The phenotypes of heterozygous and homozygous familial hypercholesterolaemia overlap considerably; the response to treatment is also heterogeneous. In this Review, we aim to define a phenotype for severe familial hypercholesterolaemia and identify people at highest risk for cardiovascular disease, based on the concentration of LDL cholesterol in blood and individuals' responsiveness to conventional lipid-lowering treatment. We assess the importance of molecular characterisation and define the role of other cardiovascular risk factors and advanced subclinical coronary atherosclerosis in risk stratification. Individuals with severe familial hypercholesterolaemia might benefit in particular from early and more aggressive cholesterol-lowering treatment (eg, with PCSK9 inhibitors). In addition to better tailored therapy, more precise characterisation of individuals with severe familial hypercholesterolaemia could improve resource use.

Progress in the care of common inherited atherogenic disorders of apolipoprotein B metabolism

Familial hypercholesterolaemia, familial combined hyperlipidaemia (FCH) and elevated lipoprotein(a) are common, inherited disorders of apolipoprotein B metabolism that markedly accelerate the onset of atherosclerotic cardiovascular disease (ASCVD). These disorders are frequently encountered in clinical lipidology and need to be accurately identified and treated in both index patients and their family members, to prevent the development of premature ASCVD. The optimal screening strategies depend on the patterns of heritability for each condition. Established therapies are widely used along with lifestyle interventions to regulate levels of circulating lipoproteins. New therapeutic strategies are becoming available, and could supplement traditional approaches in the most severe cases, but their long-term cost-effectiveness and safety have yet to be confirmed. We review contemporary developments in the understanding, detection and care of these highly atherogenic disorders of apolipoprotein B metabolism.