Familial hypercholesterolaemia in patients with ischaemic stroke or transient ischaemic attack

The prevalence and treatment patterns of familial hypercholesterolemia among Thai patients with premature coronary artery disease

OBJECTIVES

Familial hypercholesterolemia (FH) is an autosomal dominant genetic disorder that is characterized by severe hypercholesterolemia. The prevalence of FH in Thailand has not been reported. Therefore, this study aimed to investigate the prevalence of FH and treatment patterns among Thai patients with premature coronary artery disease (pCAD).

METHODS

A total of 1,180 pCAD patients at two heart centers from northeastern and southern Thailand between October 2018 and September 2020 were enrolled. FH was diagnosed using the Dutch Lipid Clinic Network (DLCN) criteria. pCAD was diagnosed in men aged < 55 years and women aged < 60 years.

RESULTS

The prevalence of definite/probable FH, possible FH, and unlikely FH in pCAD patients was 1.36% (n = 16), 24.83% (n = 293), and 73.81% (n = 871), respectively. Definite/probable FH in pCAD patients had a significantly higher frequency of STEMI but a lower frequency of hypertension than those with unlikely FH. After discharge, most pCAD patients (95.51%) received statin therapy. Definite/probable FH patients had a higher frequency of high-intensity statin therapy than those with possible FH and unlikely FH. After follow-up for 3-6 months, approximately 54.72% of pCAD patients with DLCN scores ≥ 5 had a reduction in LDL-C > 50% from baseline.

CONCLUSIONS

The prevalence of definite/probable FH, particularly possible FH, was high among pCAD patients in this study. The early diagnosis of FH among Thai pCAD patients should be performed for the early treatment and prevention of CAD.

Familial hypercholesterolaemia and coronary risk factors among patients with angiogram-proven premature coronary artery disease in an Asian cohort

Background

Familial hypercholesterolaemia (FH) patients have elevated levels of low-density lipoprotein cholesterol, rendering them at high risk of premature coronary artery disease (PCAD). However, the FH prevalence among angiogram-proven PCAD (AP-PCAD) patients and their status of coronary risk factors (CRFs) have not been reported in the Asian population.

Objectives

This study aimed to (1) determine the prevalence of clinically diagnosed FH among AP-PCAD patients, (2) compare CRFs between AP-PCAD patients with control groups, and (3) identify the independent predictors of PCAD.

Methods

AP-PCAD patients and FH patients without PCAD were recruited from Cardiology and Specialist Lipid Clinics. Subjects were divided into AP-PCAD with FH (G1), AP-PCAD without FH (G2), FH without PCAD (G3) and normal controls (G4). Medical records were collected from the clinic database and standardised questionnaires. FH was clinically diagnosed using Dutch Lipid Clinic Network Criteria.

Results

A total of 572 subjects were recruited (males:86.4%; mean±SD age: 55.6±8.5years). The prevalence of Definite, Potential and All FH among AP-PCAD patients were 6%(19/319), 16% (51/319) and 45.5% (145/319) respectively. G1 had higher central obesity, family history of PCAD and family history of hypercholesterolaemia compared to other groups. Among all subjects, diabetes [OR(95% CI): 4.7(2.9,7.7)], hypertension [OR(95% CI): 14.1(7.8,25.6)], FH [OR(95% CI): 2.9(1.5,5.5)] and Potential (Definite and Probable) FH [OR(95% CI): 4.5(2.1,9.6)] were independent predictors for PCAD. Among FH patients, family history of PCAD [OR(95% CI): 3.0(1.4,6.3)] and Definite FH [OR(95% CI): 7.1(1.9,27.4)] were independent predictors for PCAD.

Conclusion

Potential FH is common among AP-PCAD patients and contributes greatly to the AP-PCAD. FH-PCAD subjects have greater proportions of various risk factors compared to other groups. Presence of FH, diabetes, hypertension, obesity and family history of PCAD are independent predictors of PCAD. FH with PCAD is in very-high-risk category, hence, early management of modifiable CRFs in these patients are warranted.

Characterization of familial hypercholesterolemia in Taiwanese ischemic stroke patients

Familial hypercholesterolemia (FH) is a common genetic disorder characterized by a lifelong elevated low-density lipoprotein cholesterol (LDL-C) level. The relationship between FH and ischemic stroke is still controversial. We enrolled ischemic stroke patients prospectively in our neurological ward, and divided them into two groups according to LDL-C levels with a threshold of 130 mg/dl. Targeted sequencing was performed in all stroke patients for LDLR, APOB, and PCSK9 genes. The fifty-eight high-LDL subjects were older, prevalence of previous myocardial infarction/stroke history was lower, and the first stroke age was older compared with values in the sixty-three low-LDL cases. The prevalence of FH in Han-Chinese stroke patients was 5.0%, and was 10.3% in those with a higher LDL-C level. We identified six carriers, who had higher percentages of large vessel stroke subtype (66.7% vs. 15.4%) and transient ischemic attack (33.3% vs. 3.8%), previous myocardial infarction/stroke history (50.0% vs. 11.5%), statin use (50.0% vs. 11.5%), and increased carotid intima-media thickness (IMT) (0.9-1.2mm vs.0.7-9.0mm) compared with the other hypercholesterolemic patients without pathogenic variants. Ischemic stroke patients carrying FH pathogenic variants seemed to have a higher risk for large artery stroke and transient ischemic attack. The IMT exam could be useful to screen for FH in hypercholesterolemic stroke patients.

Identifying familial hypercholesterolemia in an early onset ischemic cerebrovascular disease patient and the cascade screening in the pedigree: a case report

Familial hypercholesterolemia (FH) is one of the most common inherited metabolic disorders characterized by elevated low-density lipid cholesterol (LDL-C) levels that lead to coronary artery disease at an early age and a low occurrence of cerebrovascular disease. Low-density lipoprotein receptor (LDLR) gene mutation is the most common cause of FH. Here, we report a case of a 47-year-old woman who had multiple carotid artery stenosis and brain ischemic foci, an elevated level of LDL-C, underwent eyelid xanthoma excision, and a family history of hyperlipidemia. Thereafter, she was diagnosed with FH according to the Dutch Lipid Clinical Network criteria and whole genome sequencing revealed compound heterozygous LDLR mutations. However, she denied a history of coronary heart disease (CAD). The patient underwent stenting of the right subclavicular artery and right internal carotid artery in our hospital. Lipid-lowering drugs were also administered to prevent stroke recurrence. During a 3-year follow-up, the blood lipid level of the patient reduced, and the condition of intracranial and extracranial vascular stenosis improved. Furthermore, a cascade screening was performed in her pedigree, and 7/9 family members were found to have elevated LDL-C, 6/7 were found to carry one of the two LDLR variants detected in the proband, and in 4/6, the carotid intima-media thickness was ≥1 mm, which was predicted as a high risk factor of cerebrovascular disease. Her relatives with high risks of cardiovascular or cerebrovascular diseases have been under lipid monitoring and management of risk factors since then. To date, no cardiovascular or cerebrovascular event has been reported. In conclusion, this case reminds us to consider FH screening in early-onset stroke or transient ischemic attack patients with elevated LDL-C level. Our report also demonstrates the beneficial role of genetic testing and cascade screening in the relatives of FH patients.

Prevalence of Familial Hypercholesterolemia Among the General Population and Patients With Atherosclerotic Cardiovascular Disease

Background:

Contemporary studies suggest that familial hypercholesterolemia (FH) is more frequent than previously reported and increasingly recognized as affecting individuals of all ethnicities and across many regions of the world. Precise estimation of its global prevalence and prevalence across World Health Organization regions is needed to inform policies aiming at early detection and atherosclerotic cardiovascular disease (ASCVD) prevention. The present study aims to provide a comprehensive assessment and more reliable estimation of the prevalence of FH than hitherto possible in the general population (GP) and among patients with ASCVD.

Methods:

We performed a systematic review and meta-analysis including studies reporting on the prevalence of heterozygous FH in the GP or among those with ASCVD. Studies reporting gene founder effects and focused on homozygous FH were excluded. The search was conducted through Medline, Embase, Cochrane, and Global Health, without time or language restrictions. A random-effects model was applied to estimate the overall pooled prevalence of FH in the general and ASCVD populations separately and by World Health Organization regions.

Results:

From 3225 articles, 42 studies from the GP and 20 from populations with ASCVD were eligible, reporting on 7 297 363 individuals/24 636 cases of FH and 48 158 patients/2827 cases of FH, respectively. More than 60% of the studies were from Europe. Use of the Dutch Lipid Clinic Network criteria was the commonest diagnostic method. Within the GP, the overall pooled prevalence of FH was 1:311 (95% CI, 1:250–1:397; similar between children [1:364] and adults [1:303], P =0.60; across World Health Organization regions where data were available, P =0.29; and between population-based and electronic health records–based studies, P =0.82). Studies with ≤10 000 participants reported a higher prevalence (1:200–289) compared with larger cohorts (1:365–407; P <0.001). The pooled prevalence among those with ASCVD was 18-fold higher than in the GP (1:17 [95% CI, 1:12–1:24]), driven mainly by coronary artery disease (1:16; [95% CI, 1:12–1:23]). Between-study heterogeneity was large ( I 2 >95%). Tests assessing bias were nonsignificant ( P >0.3).

Conclusions:

With an overall prevalence of 1:311, FH is among the commonest genetic disorders in the GP, similarly present across different regions of the world, and is more frequent among those with ASCVD. The present results support the advocacy for the institution of public health policies, including screening programs, to identify FH early and to prevent its global burden.

Risk of Ischemic Stroke and Total Cerebrovascular Disease in Familial Hypercholesterolemia: A Register Study From Norway

Background and Purpose- Familial hypercholesterolemia (FH) is a common autosomal dominant disease leading to increased level of serum LDL (low-density lipoprotein) cholesterol and risk of coronary heart disease. Whether FH increases the risk of cerebrovascular disease, including ischemic stroke, is debated. Accordingly, we studied the incidence of cerebrovascular disease in a cohort of people with genetically verified FH compared with the entire Norwegian population and examined whether people in this cohort with previous cohort had increased risk of cerebrovascular disease. Methods- Incidence rates of hospitalization for cerebrovascular disease (among 3144 people with FH) and ischemic stroke (among 3166 people with FH) were estimated by linkage of FH people to Cardiovascular Disease in Norway-a nationwide database of cardiovascular disease hospitalizations (2001-2009). We calculated standardized incidence ratios and used Cox regression to estimate hazard ratios. Results- A total of 46 cases (19 women and 27 men) of cerebrovascular disease were observed in the cohort of people with FH, with no increased risk of cerebrovascular disease compared with the general population (standardized incidence ratio, 1.0; 95% CI, 0.8-1.4). Total number of ischemic strokes in the cohort of people with FH was 26 (9 women and 17 men), with no increased risk compared with the general population (standardized incidence ratio, 1.0; 95% CI, 0.7-1.5). Prior coronary heart disease significantly increased cerebrovascular disease risk in women (hazard ratio, 3.29; 95% CI, 1.20-9.00) but not in men (hazard ratio, 1.03; 95% CI, 0.45-2.37; Pinteraction=0.04). Conclusions- In a large cohort of genetically verified FH, risks of cerebrovascular disease and ischemic stroke were not increased compared with the total Norwegian population.

Improving the detection of familial hypercholesterolaemia

Familial hypercholesterolaemia (FH) is a dominantly inherited disorder of low-density lipoprotein (LDL) catabolism, which if untreated causes lifelong elevated LDL-cholesterol (LDL-c), accelerated atherosclerosis and premature cardiovascular disease. Recent evidence suggests the prevalence of heterozygous FH is ∼1:220, making FH the most common autosomal dominant condition. Lowering LDL-c with statin and lifestyle therapy reduces the risk of cardiovascular events. Furthermore, proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors significantly lower LDL-c in addition to statin therapy, and early outcome data suggest improved vascular outcomes with these agents in FH patients in addition to statins. However, the vast majority of people with FH still remain undiagnosed. The onus is on clinicians to identify kindreds with FH, as PCSK9 inhibitors, although expensive, are funded for patients with FH in Australia. Multiple strategies for detecting FH have been proposed. The detection of index cases can be achieved through applying electronic screening tools to general practice databases, universal screening of children during immunisation, and targeted screening of patients with premature cardiovascular disease. Advances in genomic technology have decreased costs of genetic testing, improved the understanding of the pathogenesis of FH and facilitated cascade screening. However, awareness of FH amongst clinicians and the general public still requires optimisation. This review outlines recent advances in FH detection, including emerging strategies and challenges for the next decade.