Cardiovascular risk stratification in familial hypercholesterolaemia

Polygenic risk score predicts prevalence of cardiovascular disease in patients with familial hypercholesterolemia

BACKGROUND

Although familial hypercholesterolemia (FH) is a severe monogenic disease, it has been shown that clinical risk factors and common genetic variants can modify cardiovascular disease (CVD) risk.

OBJECTIVE

The aim of the study was to evaluate the polygenic contribution to lipid traits and CVD in FH using genetic risk scores (GRSs).

METHODS

Among the 20,434 subjects attending the lipid clinic, we identified and included 725 individuals who carried an FH causing mutation in this retrospective cohort study. We evaluated the association of GRSs for several traits including coronary artery disease (CAD; GRS_CAD) as well as plasma concentrations of low-density lipoprotein cholesterol (LDL-C; GRS_LDL-C), high-density lipoprotein cholesterol (GRS_HDL-C) and triglycerides (GRS_TG).

RESULTS

A total of 32% (n = 231) of FH subjects presented a CVD event before their first visit. Patients in the highest GRS_LDL-C tertile presented an LDL-C 0.4 mmol/L (15.5 mg/dL) higher than the subjects in the lowest tertile (P = .01). The GRS_CAD was strongly associated with CVD events (odds ratio 1.80; 95% confidence interval 1.14-2.85; P = .01) even after adjustment for cardiovascular risk factors. Compared with subjects in the first tertile, those in the third GRS_CAD tertile had a significantly higher prevalence of events (40.9% vs 24.7%, P < .0001) and a significantly higher number of events (average 0.97 vs 0.57 [P = .0001] events per individual).

CONCLUSION

These results indicate that even in the context of a severe monogenic disease such as FH, common genetic variants can significantly modify the disease phenotype. The use of the 192-SNPs GRS_CAD may refine CVD risk prediction in FH patients and this could lead to a more personalized approach to therapy.

Clinical determinants and treatment gaps in familial hypercholesterolemia: Data from a multi-ethnic regional health service

Background Familial hypercholesterolemia is characterized by markedly increased low-density lipoprotein cholesterol and risk for premature atherosclerotic cardiovascular disease. Models of care vary and reflect differing health policies and resources. The availability of electronic databases may enable better identification and assessment of familial hypercholesterolemia in the community. Methods A regional healthcare database was utilized to identify patients with a high probability of familial hypercholesterolemia, clinically defined by age-dependent-peak low-density lipoprotein cholesterol cutoffs and exclusion of secondary causes of severe hypercholesterolemia. Clinical characteristics, low-density lipoprotein cholesterol goal attainment, and treatment gaps were investigated. Results Probable familial hypercholesterolemia was diagnosed in 1932 of 685,314 individuals (1:355; median age 47 years). Atherosclerotic cardiovascular disease was present in 16.3% of adults (38% in males aged 50-74 years). Median peak low-density lipoprotein cholesterol was 264 mg/dl (interquartile range 252-288). Statins and/or ezetimibe were prescribed to 83% of patients and high-intensity statins to 53%, whereas prescriptions were filled in 57% and 40% cases respectively over the last six months, p < 0.001. Treatment gaps were wider among ethnic minorities, younger individuals, and those without atherosclerotic cardiovascular disease. Low-density lipoprotein cholesterol < 100 mg/dl was attained in 10.1% overall and 28.7% of those with atherosclerotic cardiovascular disease. Predictors of low-density lipoprotein cholesterol goal attainment included recent issue of high-intensity statins, presence of atherosclerotic cardiovascular disease, diabetes, older age and lack of smoking. Conclusions The population with high probability for familial hypercholesterolemia was characterized by low attainment of low-density lipoprotein cholesterol treatment goals despite high prescription rates of lipid-lowering medications. Low utilization of intensified therapies, non-adherence, and ethnic disparities were contributing factors. These findings emphasize the need to improve awareness and quality of care of familial hypercholesterolemia in the community.

The panorama of familial hypercholesterolemia in Latin America: a systematic review

The burden caused by familial hypercholesterolemia (FH) varies among countries and ethnic groups. The prevalence and characteristics of FH in Latin American (LA) countries is largely unknown. We present a systematic review (following the PRISMA statement) of FH in LA countries. The epidemiology, genetics, screening, management, and unique challenges encountered in these countries are discussed. Published reports discussing FH in Hispanic or LA groups was considered for analysis. Thirty studies were included representing 10 countries. The bulk of the data was generated in Brazil and Mexico. Few countries have registries and there was little commonality in FH mutations between LA countries. LDL receptor mutations predominate; APOB and PCSK9 mutations are rare. No mutation was found in an FH gene in nearly 50% of cases. In addition, some country-specific mutations have been reported. Scant information exists regarding models of care, cascade screening, cost, treatment effectiveness, morbidity, and mortality. In conclusion, FH is largely underdiagnosed and undertreated in the LA region. The genetic admixture with indigenous populations, producing mestizo's groups, may influence the mutational findings in Latin America. Potential opportunities to close gaps in knowledge and health care are identified.