Are Genetic Tests for Atherosclerosis Ready for Routine Clinical Use?

Impact of providing genetics-based future cardiovascular risk on LDL-C in patients with familial hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia (FH) is an autosomal dominant monogenic disease characterized by high low-density lipoprotein cholesterol (LDL-C) levels. Although carrying causative FH variants is associated with coronary heart disease (CHD), it remains unclear whether disclosing its associated cardiovascular risk affects outcomes in patients with FH.

OBJECTIVE

We aimed to evaluate the efficacy of providing future cardiovascular risk based on genetic testing in addition to a standard FH education program.

METHODS

We conducted a randomized, wait-list controlled, open-label, single-center trial. In the intervention group, we reported a future cardiovascular risk based on the genetic testing adding to standard FH education at week 0. In the wait-list control group, we only disseminated standard FH education according to the guidelines at week 0; they later received a genetic testing-based cardiovascular risk assessment at week 24. The primary endpoint of this study was the plasma LDL-C level at week 24.

RESULTS

Fifty eligible patients with clinically diagnosed FH, without a history of CHD, were allocated to the intervention group (n = 24) or the wait-list control group (n = 26). At week 24, the intervention group had a significantly greater reduction in LDL-C levels than the wait-list control group (mean changes, -13.1 mg/dL vs. 6.6 mg/dL; difference, -19.7 mg/dL; 95% confidence interval, -34 to -5.6; p = 0.009). This interventional effect was consistent with FH causative variant carriers but not with non-carriers.

CONCLUSIONS

In addition to standard FH care, providing future cardiovascular risk based on genetic testing can further reduce plasma LDL-C levels, particularly among FH causal variant carriers.

REGISTRATION

Japan Registry of Clinical Trials (jRCTs04218002). URL: https://jrct.niph.go.jp/latest-detail/jRCTs042180027.

Incremental Value of Polygenic Risk Scores in Primary Prevention of Coronary Heart Disease: A Review

IMPORTANCE

Risk prediction for coronary heart disease (CHD) is a cornerstone of primary prevention strategies. Polygenic risk scores (PRSs) have emerged as a new approach to predict risk in asymptomatic people. Polygenic risk scores for CHD have been studied in several populations, but there is lack of agreement about the incremental value of PRS beyond traditional risk factor scores in the primary prevention of CHD.

OBSERVATIONS

This narrative review critically appraised the 5 most highly cited studies published through 2021 that also included a large number (>45 000) of single-nucleotide variations (formerly single-nucleotide polymorphisms) and evaluated the incremental value of PRS in CHD risk prediction according to published PRS reporting standards. The cohorts studied included the Atherosclerosis Risk in Communities Study, FINRISK, the Framingham Heart Study, the Multi-Ethnic Study of Atherosclerosis, and the UK Biobank. All of the studies focused predominantly on populations of European ancestry. The hazard ratio per standard deviation of PRS ranged from 1.24 (95% CI, 1.15-1.34) to 1.74 (95% CI, 1.61-1.86). The C statistic for PRS alone ranged from 0.549 to 0.623. The change in C statistic when PRS was added to a standard risk factor model ranged between -0.001 to +0.021. Net reclassification index was reported in 4 of the 5 studies and varied from 0.001 to 0.097. At a sensitivity (true-positive rate) of 90%, positive predictive values ranged from 1.8% to 16.6%, and false-positive rates ranged from 77.1% to 85.7%.

CONCLUSIONS AND RELEVANCE

In this review, PRS was significantly associated with CHD risk in all studies. The degree of improvement in C statistic and the net reclassification indexes when PRS was added to traditional risk scores ranged from negligible to modest. Based on established metrics to assess risk prediction scores, the addition of PRS to traditional risk scores does not appear to provide meaningful improvements in clinical decision-making in primary prevention populations.

Influence of Nursing Intervention Based on Risk Assessment Model on Self-Efficacy and Postoperative Rehabilitation of Surgical Patients

The study aims to explore the effect of nursing intervention based on risk assessment model on self-efficacy and postoperative rehabilitation of surgical patients. The study applied a risk assessment model to the behavioral intervention of rehabilitation exercise in patients after percutaneous coronary intervention (PCI). A total of 157 patients were selected from a certain hospital, with 52 cases in the experimental group and 55 cases in the control group. A comprehensive cardiac rehabilitation intervention strategy based on TTM is given by researchers trained with professional knowledge, including dividing the stages of behavior change, developing a rehabilitation exercise plan through exercise teaching and exercise training, diet and lifestyle guidance, and urging patients to take regular medication and regular follow-up. The stage of rehabilitation movement behavior change improved. The preexperiment health status was (35.39 ± 14.31), and the overall health of the control group was (32.59 ± 15.41). Overall health status and QOL scores were relatively low in both the groups. The intervention group scored higher than the control group. After coronary stent implantation, the heart restores its original pumping function, various organs and tissues receive effective blood perfusion, and the symptoms of myocardial infarction such as profuse sweating, dizziness, fatigue, and precordial discomfort are effectively relieved. The physical discomfort can gradually improve or even recover to the functional state before the onset of the disease. Before the intervention, the self-efficacy score of the intervention group was (23.68 ± 4.49). After the intervention, the self-efficacy score of the intervention group was (26.21 ± 4.09), while the self-efficacy score of the control group before the intervention was (22.21 ± 4.1). After the intervention, the self-efficacy score of the control group was (25.23 ± 4.41). Although the self-efficacy score of the control group was improved, the difference was small, and the intervention effect was not obvious. It indicates that risk assessment intervention can improve patients' self-efficacy level and quality of life of postoperative rehabilitation patients.

Clinical Phenotypes of Cardiovascular and Heart Failure Diseases Can Be Reversed? The Holistic Principle of Systems Biology in Multifaceted Heart Diseases

Recent advances in cardiology and biological sciences have improved quality of life in patients with complex cardiovascular diseases (CVDs) or heart failure (HF). Regardless of medical progress, complex cardiac diseases continue to have a prolonged clinical course with high morbidity and mortality. Interventional coronary techniques together with drug therapy improve quality and future prospects of life, but do not reverse the course of the atherosclerotic process that remains relentlessly progressive. The probability of CVDs and HF phenotypes to reverse can be supported by the advances made on the medical holistic principle of systems biology (SB) and on artificial intelligence (AI). Studies on clinical phenotypes reversal should be based on the research performed in large populations of patients following gathering and analyzing large amounts of relative data that embrace the concept of complexity. To decipher the complexity conundrum, a multiomics approach is needed with network analysis of the biological data. Only by understanding the complexity of chronic heart diseases and explaining the interrelationship between different interconnected biological networks can the probability for clinical phenotypes reversal be increased.

A Bibliometric Analysis of Familial Hypercholesterolemia From 2011 to 2021

Familial Hypercholesterolemia (FH), an autosomal dominant genetic disease, is increasingly emerging as a global threat. To learn more about the development of FH, 1 617 papers about FH and related research were retrieved in the Web of Science Core Collection from 2011 to 2021. Then, these publications were scientometrically analyzed based on CiteSpace and VOSviewer in terms of spatiotemporal distribution, author distribution, subject categories, topic distribution, and references. The results showed that research on FH is at a stable stage. More FH research has been conducted in developed countries, implying the necessity for strengthening international cooperation and exchanges. We have obtained scholars, institutions, relevant journals, and representative literatures that play an important role in FH. The research direction of FH is on the mechanisms of FH and its complications, diagnosis, statin therapy, and new lipid-lowering drug therapy. Care is the research frontier in FH, and it is in an explosive period.

Acetaldehyde Dehydrogenase 2 regulates HMG-CoA reductase stability and cholesterol synthesis in the liver

HMG-CoA reductase (HMGCR) is the rate-limiting enzyme in cholesterol biosynthesis and the target for cholesterol-lowering therapy. Acetaldehyde dehydrogenase 2 (ALDH2) is primarily responsible for detoxifying ethanol-derived acetaldehyde and endogenous lipid aldehydes derived from lipid peroxidation. Epidemiological and Genome Wide Association Studies (GWAS) have linked an inactive ALDH2 rs671 variant, responsible for alcohol flush in nearly 8% world population and 40% of Asians, with cholesterol levels and higher risk of cardiovascular disease (CVD) but the underlying mechanism remains elusive. Here we find that the cholesterol levels in the serum and liver of ALDH2 knockout (AKO) and ALDH2 rs671 knock-in (AKI) mice are significantly increased, consistent with the increase of intermediates in the cholesterol biosynthetic pathways. Mechanistically, mitochondrial ALDH2 translocates to the endoplasmic reticulum to promote the formation of GP78/Insig1/HMGCR complex to increase HMGCR degradation through ubiquitination. Conversely, ALDH2 mutant or ALDH2 deficiency in AKI or AKO mice stabilizes HMGCR, resulting in enhanced cholesterol synthesis, which can be reversed by Lovastatin. Moreover, ALDH2-regulated cholesterol synthesis is linked to the formation of mitochondria-associated endoplasmic reticulum membranes (MAMs). Together, our study has identified that ALDH2 is a novel regulator of cholesterol synthesis, which may play an important role in CVD.

Screening for Rare Genetic Variants Associated with Atherosclerosis: Opportunity for Personalized Medicine

Atherosclerosis and its clinical manifestations is a leading cause of disease burden worldwide. Currently, most of the individuals carrying a strong predisposition to complications of atherosclerosis because of monogenic dyslipidaemias remain undiagnosed and consequently are not given an opportunity for prevention. Therefore, one of the main public health challenges remains the identification of individuals with significantly increased risk for atherosclerosis due to monogenic predisposition. Next-Generation Sequencing (NGS) has revolutionized genetic testing in symptomatic patients. Although new genomic technologies are still developing, and evidence on the use of this methodology for screening purposes is still lacking, genome testing might provide a powerful tool for the identification of individuals at risk. This may pave the way for the implementation of personalized medicine in the field of atherosclerosis prevention. In this review, we discuss the potential of genetic screening for atherosclerosis prevention and present the potential target of 17 genes responsible for monogenic dyslipidaemias associated with atherosclerosis.

Genetics, coronary artery disease, and myocardial revascularization: will novel genetic risk scores bring new answers?

Both percutaneous coronary intervention (PCI) and coronary artery bypass graft surgery (CABG) are options for revascularization in multi-vessel coronary artery disease (CAD). However, the best form of revascularization remains controversial. Results from clinical trials (FREEDOM, SYNTAX, NOBLE, EXCEL) have identified factors related to CAD severity such as diabetes and SYNTAX score as indicators that patients may have better outcomes with CABG compared to PCI. Nevertheless, the discovery of other predictors of optimal revascularization therapy is necessary to improve decision-making and personalize the treatment of multi-vessel CAD. Genome-wide association studies have identified numerous previously unknown DNA variants that increase predisposition for CAD. Recently, a composite polygenic risk score has been developed to better assess the relative contribution of multiple SNPs and quantify overall genetic risk for CAD. High polygenic risk score is associated with increased coronary events and greater benefit from statin therapy in large observational studies. This effect is independent from traditional cardiovascular risk factors. At the same time, randomized clinical trials have shown that CAD severity is a determinant of optimal revascularization treatment. It remains unknown whether polygenic risk score is robustly associated with increased CAD severity at presentation, and whether this score can be used to identify patients who will show greater benefit from revascularization with CABG or with PCI.

Markers of Atherosclerosis: Part 2 - Genetic and Imaging Markers

This is Part 2 of a two-part review summarising current knowledge on biomarkers of atherosclerosis. Part 1 addressed serological biomarkers. Here, in part 2 we address genetic and imaging markers, and other developments in predicting risk. Further improvements in risk stratification are expected with the addition of genetic risk scores. In addition to single nucleotide polymorphisms (SNPs), recent advances in epigenetics offer DNA methylation profiles, histone chemical modifications, and micro-RNAs as other promising indicators of atherosclerosis. Imaging biomarkers are better studied and already have a higher degree of clinical applicability in cardiovascular (CV) event prediction and detection of preclinical atherosclerosis. With new methodologies, such as proteomics and metabolomics, discoveries of new clinically applicable biomarkers are expected.

Nontraditional Cardiovascular Biomarkers and Risk Factors: Rationale and Future Perspectives

The primary prevention of cardiovascular (CV) disease depends on the capacity to identify subjects at higher risk long before the occurrence of CV clinical manifestations. Traditional risk factors do not cover fully prediction of individual risk. Moreover, there is an area of gray for patients at intermediate CV risk, which offers wide margins of improvement. These observations highlight the need for new additive tools for a more accurate risk stratification. An increasing number of candidate biomarkers have been identified to predict CV risk and events, although they generally give only a moderate increase when added to currently available predictive scores. The approach utilizing a relative small number of biomarkers in multiple combinations, but only weakly related to each other or unrelated, thus belonging to independent-pathways, and so able to catch the multidimensional characteristic of atherosclerosis, appears promising. We discuss vitamin D and bone turnover biomarkers, hepatitis C virus, and psycho-emotional factors that may reflect alternative pathways over those generally considered for atherosclerosis (e.g., aspects directly related to inflammation and thrombosis). These new biomarkers could facilitate a more accurate assessment of CV risk stratification if incorporated in the current risk assessment algorithms.

Molecular aspects of hypercholesterolemia treatment: current perspectives and hopes

Hypercholesterolemia is a pathological condition which has been reported in 39% of the worlds' adult population. We aimed to review molecular aspects of current and novel therapeutic approaches based on low-density lipoprotein cholesterol lowering strategies. Pathogenic mutations in the LDLR, ApoB, PCSK9 and LDLRAP genes cause deficient clearance of circulating low-density lipoprotein cholesterol particles via hepatic LDL receptor. This leads to increased plasma LDL cholesterol levels from birth, which can cause LDL depositions in the arterial walls. Ultimately, it progresses to atherosclerosis and an increased risk of premature cardiovascular diseases. Currently, statins, Ezetimibe, Bile acid sequestrants and PCSK9 inhibitors are the main therapeutic agents for the treatment of hypercholesterolemia. Moreover, novel RNA-based therapy had a strong impact on therapeutic strategies in recent decades. Additional development in understanding of the molecular basis of hypercholesterolemia will provide opportunities for the development of targeted therapy in the near future. Key Messages The most common genes involved in hypercholesterolemia are LDLR, PCSK9 and ApoB. Pharmacogenetic effects are typically constrained to pathways closely related to the pharmacodynamics and pharmacokinetics. Change in lifestyle and diet along with treatment of the underlying disease and drug therapy are the current therapeutic strategies.

Genetic Markers for Coronary Artery Disease

Coronary artery disease (CAD) and myocardial infarction (MI) are recognized as leading causes of mortality in developed countries. Although typically associated with behavioral risk factors, such as smoking, sedentary lifestyle, and poor dietary habits, such vascular phenotypes have also long been recognized as being related to genetic background. We review the currently available data concerning genetic markers for CAD in English and non-English articles with English abstracts published between 2003 and 2018. As genetic testing is increasingly available, it may be possible to identify adequate genetic markers representing the risk profile and to use them in a clinical setting.

Weighted Multi-marker Genetic Risk Scores for Incident Coronary Heart Disease among Individuals of African, Latino and East-Asian Ancestry

We examined the clinical utility of two multi-locus genetic risk scores (GRSs) previously validated in Europeans among persons of African (AFR; n = 2,089), Latino (LAT; n = 4,349) and East-Asian (EA; n = 4,804) ancestry. We used data from the GERA cohort (30-79 years old, 68 to 73% female). We utilized two GRSs with 12 and 51 SNPs, respectively, and the Framingham Risk Score (FRS) to estimate 10-year CHD risk. After a median 8.7 years of follow-up, 450 incident CHD events were documented (95 in AFR, 316 in LAT and 39 EA, respectively). In a model adjusting for principal components and risk factors, tertile 3 vs. tertile 1 of GRS_12 was associated with 1.86 (95% CI, 1.15-3.01), 1.52 (95% CI, 1.02-2.25) and 1.19 (95% CI, 0.77-1.83) increased hazard of CHD in AFR, LAT and EA, respectively. Inclusion of the GRSs in models containing the FRS did not increase the C-statistic but resulted in net overall reclassification of 10% of AFR, 7% LAT and EA and in reclassification of 13% of AFR and EA as well as 10% LAT in the intermediate FRS risk subset. Our results support the usefulness of incorporating genetic information into risk assessment for primary prevention among minority subjects in the U.S.

Cardiovascular Genetic Risk Testing for Targeting Statin Therapy in the Primary Prevention of Atherosclerotic Cardiovascular Disease: A Cost-Effectiveness Analysis

BACKGROUND

It is unclear whether testing for novel risk factors, such as a cardiovascular genetic risk score (cGRS), improves clinical decision making or health outcomes when used for targeting statin initiation in the primary prevention of atherosclerotic cardiovascular disease (ASCVD). Our objective was to estimate the cost-effectiveness of cGRS testing to inform clinical decision making about statin initiation in individuals with low-to-intermediate (2.5%-7.5%) 10-year predicted risk of ASCVD.

METHODS AND RESULTS

We evaluated the cost-effectiveness of testing for a 27-single-nucleotide polymorphism cGRS comparing 4 test/treat strategies: treat all, treat none, test/treat if cGRS is high, and test/treat if cGRS is intermediate or high. We tested a set of clinical scenarios of men and women, aged 45 to 65 years, with 10-year ASCVD risks between 2.5% and 7.5%. Our primary outcome measure was cost per quality-adjusted life-year gained. Under base case assumptions for statin disutility and cost, the preferred strategy is to treat all patients with ASCVD risk >2.5% without cGRS testing. For certain clinical scenarios, such as a 57-year-old man with a 10-year ASCVD risk of 7.5%, cGRS testing can be cost-effective under a limited set of assumptions; for example, when statins cost $15 per month and statin disutility is 0.013 (ie, willing to trade 3 months of life in perfect health to avoid 20 years of statin therapy), the preferred strategy (using a willingness-to-pay threshold of $50 000 per quality-adjusted life-year gained) is to test and treat if cGRS is intermediate or high. Overall, the results were not sensitive to assumptions about statin efficacy and harms.

CONCLUSIONS

Testing for a 27-single-nucleotide polymorphism cGRS is generally not a cost-effective approach for targeting statin therapy in the primary prevention of ASCVD for low- to intermediate-risk patients.

Application of Single-Nucleotide Polymorphism-Related Risk Estimates in Identification of Increased Genetic Susceptibility to Cardiovascular Diseases: A Literature Review

Background

Although largely preventable, cardiovascular diseases (CVDs) are the biggest cause of death worldwide. Common complex cardiovascular disorders (e.g., coronary heart disease, hypertonia, or thrombophilia) result from a combination of genetic alterations and environmental factors. Recent advances in the genomics of CVDs have fostered huge expectations about future use of susceptibility variants for prevention, diagnosis, and treatment. Our aim was to summarize the latest developments in the field from a public health perspective focusing on the applicability of data on single-nucleotide polymorphisms (SNPs), through a systematic review of studies from the last decade on genetic risk estimating for common CVDs.

Methods

Several keywords were used for searching the PubMed, Embase, CINAHL, and Web of Science databases. Recent advances were summarized and structured according to the main public health domains (prevention, early detection, and treatment) using a framework suggested recently for translational research. This framework includes four recommended phases: “T1. From gene discovery to candidate health applications; T2. From health application to evidence-based practice guidelines; T3. From evidence-based practice guidelines to health practice; and T4. From practice to population health impacts.”

Results

The majority of translation research belongs to the T1 phase “translation of basic genetic/genomic research into health application”; there are only a few population-based impacts estimated. The studies suggest that an SNP is a poor estimator of individual risk, whereas an individual’s genetic profile combined with non-genetic risk factors may better predict CVD risk among certain patient subgroups. Further research is needed to validate whether these genomic profiles can prospectively identify individuals at risk to develop CVDs. Several research gaps were identified: little information is available on studies suggesting “Health application to evidence-based practice guidelines”; no study is available on “Guidelines to health practice.” It was not possible to identify studies that incorporate environmental or lifestyle factors in the risk estimation.

Conclusion

Currently, identifying populations having a larger risk of developing common CVDs may result in personalized prevention programs by reducing people’s risk of onset or disease progression. However, limited evidence is available on the application of genomic results in health and public health practice.

A decade of progress on the genetic basis of coronary artery disease. Practical insights for the internist

Clinicians are well aware of the importance of a positive family history for coronary artery disease (CAD). Nonetheless, elucidation of the genetic basis of CAD has long proven difficult. The scenario changed in the last decade through the application of modern genomic technologies, like genome-wide association studies (GWAS) and next generation sequencing (NGS). GWAS have discovered over 60 common variants highly associated with CAD. For predictive purposes, such variants have been used to build up Genetic Risk Scores (GRSs), but their incorporation into classical prediction models does not appear substantially outperform the simple addition of family history. To date, the only strong case for the utility of incorporating genetic testing into clinical practice is represented by the diagnosis of Familial Hypercholesterolemia (FH). On the other hand, utilization of genomic techniques has driven formidable advances into the knowledge of CAD pathophysiology, particularly by addressing controversies on the causality of some lipid fractions that had long remained unsolved because of limitations of observational epidemiology. For example, NGS-derived rare variants with strong functional effects on key-genes like ANGPTL4, APOA5, APOC3, LPL, and SCARB1, have proven useful as proxies to demonstrate the causality of triglyceride-rich lipoproteins (TRLs) at variance with HDL-cholesterol concentration, thus contributing to tear down a dogma from classical epidemiology. Moreover, such variants have paved the way for the development of new biologic drugs (i.e. monoclonal antibodies or antisense oligonucleotides) targeting key proteins like PCSK9, Lipoprotein_(a), and apolipoprotein C3. Such drugs are currently under active investigation, with first results being extremely promising.

Genetics of coronary artery disease: discovery, biology and clinical translation

Coronary artery disease is the leading global cause of mortality. Long recognized to be heritable, recent advances have started to unravel the genetic architecture of the disease. Common variant association studies have linked approximately 60 genetic loci to coronary risk. Large-scale gene sequencing efforts and functional studies have facilitated a better understanding of causal risk factors, elucidated underlying biology and informed the development of new therapeutics. Moving forwards, genetic testing could enable precision medicine approaches by identifying subgroups of patients at increased risk of coronary artery disease or those with a specific driving pathophysiology in whom a therapeutic or preventive approach would be most useful.

Novel Risk Markers and Risk Assessments for Cardiovascular Disease

The use of risk markers has transformed cardiovascular medicine, exemplified by the routine assessment of troponin, for both diagnosis and assessment of prognosis in patients with chest pain. Clinical risk factors form the basis for risk assessment of cardiovascular disease and the addition of biochemical, cellular, and imaging parameters offers further refinement. Identifying novel risk factors may allow greater risk stratification and a steady, but gradual progression toward precision medicine. Indeed, the generation of data in this area of research is explosive and when combined with new technologies and techniques provides the potential for more refined, targeted approaches to cardiovascular medicine. Although discussing the most recent developments in this field, this review article aims to strike a balance between novelty and validity by focusing on recent large sample-size studies that have been validated in a separate cohort in most cases. Risk markers related to atherosclerosis, thrombosis, inflammation, cardiac injury, and fibrosis are introduced in the context of their pathophysiology. Rapidly developing new areas, such as assessment of micro-RNA, are also explored. Subsequently the prognostic ability of these risk markers in coronary artery disease, heart failure, and atrial fibrillation is discussed in detail.

Utilizing nutritional genomics to tailor diets for the prevention of cardiovascular disease: a guide for upcoming studies and implementations

INTRODUCTION

Personalized diets based on an individual's genome to optimize the success of dietary intervention and reduce genetic cardiovascular disease (CVD) risk, is one of the challenges most frequently discussed in the scientific community. Areas covered: The authors gathered literature-based evidence on nutritional genomics and CVD phenotypes, our own results and research experience to provide a critical overview of the current situation of using nutritional genomics to tailor diets for CVD prevention and to propose guidelines for future studies and implementations. Expert commentary: Hundreds of studies on gene-diet interactions determining CVD intermediate (plasma lipids, hypertension, etc.) and final phenotypes (stroke, etc.) have furnished top-level scientific evidence for claiming that the genetic effect in cardiovascular risk is not deterministic, but can be modified by diet. However, despite the many results obtained, there are still gaps in practically applying a personalized diet design to specific genotypes. Hence, a better systemization and methodological improvement of new studies is required to obtain top-level evidence that will allow their application in the future precision nutrition/medicine. The authors propose several recommendations for tackling new approaches and applications.