Prospects for Personalized Cardiovascular Medicine

CRISPR/Cas9-edited triple-fusion reporter gene imaging of dynamics and function of transplanted human urinary-induced pluripotent stem cell-derived cardiomyocytes

PURPOSE

To investigate the post-transplantation behaviour and therapeutic efficacy of human urinary-induced pluripotent stem cell-derived cardiomyocytes (hUiCMs) in infarcted heart.

METHODS

We used clustered regularly interspaced short palindromic repeats/CRISPR-associated nuclease 9 (CRISPR/Cas9) technology to integrate a triple-fusion (TF) reporter gene into the AAVS1 locus in human urine-derived hiPSCs (hUiPSCs) to generate TF-hUiPSCs that stably expressed monomeric red fluorescent protein for fluorescence imaging, firefly luciferase for bioluminescence imaging (BLI) and herpes simplex virus thymidine kinase for positron emission tomography (PET) imaging.

RESULTS

Transplanted cardiomyocytes derived from TF-hUiPSCs (TF-hUiCMs) engrafted and proliferated in the infarcted heart as monitored by both BLI and PET imaging and significantly improved cardiac function. Under ischaemic conditions, TF-hUiCMs enhanced cardiomyocyte (CM) glucose metabolism and promoted angiogenic activity.

CONCLUSION

This study established a CRISPR/Cas9-mediated multimodality reporter gene imaging system that can determine the dynamics and function of TF-hUiCMs in myocardial infarction, which is helpful for investigating the application of stem cell therapy.

Drug therapy adherence and health outcomes in the presence of physician and patient unobserved heterogeneity

Understanding the role that drug adherence has on health outcomes in everyday clinical practice is central for the policy maker. This is particularly true when patients suffer from asymptomatic chronic conditions (e.g., hypertension, hypercholesterolaemia, and diabetes). By exploiting a unique longitudinal dataset at patient and physician level in Italy, we show that patients and physicians unobserved characteristics play an important role in determining health status, at least as important as drug adherence. Most importantly, we find that both adherence and prescribed treatment regimen effects are highly heterogeneous across physicians, highlighting their crucial role in shaping patients' health status.

Genetics of the acute coronary syndrome

Acute coronary artery syndrome in the leading cause of morbidity and mortality in Western countries, and its epidemiological burden is also constantly increasing worldwide, including Asia. Due to social and economic consequences, a number of experimental and epidemiological studies have analyzed its etiology so far, in order to develop effective preventive and treatment measures. Thanks to these studies, it is now clear that coronary artery disease (CAD) is a complex multifactorial disorder, resulting from close interaction between acquired and inherited risk factors. In particular, considerable advances were made in the last decade about our understanding of the genetic causes of CAD, mainly propelled by the progresses in whole genome scanning and the development of genome wide association studies. This narrative review is hence dedicated to explore the role of genetic factors in the risk of developing acute CAD.

How has our interest in the airway changed over 100 years?

Since the beginning of our specialty, our understanding of the link between function and facial growth and development has progressively improved. Today, we know that children with sleep-related breathing problems will often develop distinctive facial characteristics. In adults, sleep apnea can result in serious morbidity and mortality. Orthodontists can ask sleep-related questions in the health history to help identify sleep breathing disorders. Treating these patients presents unique opportunities for orthodontists to collaborate with other medical specialties to improve a patient's health and treatment outcome. Research presented in our Journal in the next century may shed new light that will help us better identify the problem and aid the specialty in developing more effective evidence-based treatment. Additional efforts are needed to understand the physiology, neurology, and genetics of sleep breathing disorders.

Radionuclide imaging of neurohormonal system of the heart

Heart failure is one of the growing causes of death especially in developed countries due to longer life expectancy. Although many pharmacological and instrumental therapeutic approaches have been introduced for prevention and treatment of heart failure, there are still limitations and challenges. Nuclear cardiology has experienced rapid growth in the last few decades, in particular the application of single photon emission computed tomography (SPECT) and positron emission tomography (PET), which allow non-invasive functional assessment of cardiac condition including neurohormonal systems involved in heart failure; its application has dramatically improved the capacity for fundamental research and clinical diagnosis. In this article, we review the current status of applying radionuclide technology in non-invasive imaging of neurohormonal system in the heart, especially focusing on the tracers that are currently available. A short discussion about disadvantages and perspectives is also included.

Clinical applications of fast liquid chromatography: a review on the analysis of cardiovascular drugs and their metabolites

One of the major challenges facing the medicine today is developing new therapies that enhance human health. To help address these challenges the utilization of analytical technologies and high-throughput automated platforms has been employed; in order to perform more experiments in a shorter time frame with increased data quality. In the last decade various analytical strategies have been established to enhance separation speed and efficiency in liquid chromatography applications. Liquid chromatography is an increasingly important tool for monitoring drugs and their metabolites. Furthermore, liquid chromatography has played an important role in pharmacokinetics and metabolism studies at these drug development stages since its introduction. This paper provides an overview of current trends in fast chromatography for the analysis of cardiovascular drugs and their metabolites in clinical applications. Current trends in fast liquid chromatographic separations involve monolith technologies, fused-core columns, high-temperature liquid chromatography (HTLC) and ultra-high performance liquid chromatography (UHPLC). The high specificity in combination with high sensitivity makes it an attractive complementary method to traditional methodology used for routine applications. The practical aspects of, recent developments in and the present status of fast chromatography for the analysis of biological fluids for therapeutic drug and metabolite monitoring, pharmacokinetic studies and bioequivalence studies are presented.

Biomarkers in cardiovascular clinical trials: past, present, future

BACKGROUND

Cardiovascular (CV) clinical trials are instrumental in understanding treatment effects and offer insights into the natural progression of CV disease. Biomarkers are a critical component of patient selection, end point definition, and safety monitoring, and clinical trials provide a platform for the discovery and validation of new biomarkers that may augment the understanding of disease mechanisms, risk stratification, and/or clinical decision-making.

CONTENT

We review the roles that biomarkers have played in CV clinical trials and roles that CV clinical trials have played and will continue to play in the discovery and validation of biomarkers and their implementation in clinical practice. Large biobanks containing multiple specimen types are increasingly being created from patients enrolled in clinical trials, and such biobanks, when coupled with advances in molecular techniques and bioinformatics, promise to accelerate our understanding of CV disease mechanisms and to help fuel the discovery and development of novel therapeutic targets and biomarkers of risk and treatment response.

SUMMARY

The past, present, and future of biomarkers and clinical trials have been and will remain intertwined. Biomarkers were once the workhorses of patient selection and end point definition in clinical trials; more recently, clinical trials have been the proving ground for individual biomarkers. Attention to biobanking and the application of modern informatics and molecular techniques to samples collected within clinical trials will usher in the era of stratified and personalized medicine.

Systems-based approaches to cardiovascular disease

Common cardiovascular diseases, such as atherosclerosis and congestive heart failure, are exceptionally complex, involving a multitude of environmental and genetic factors that often show nonlinear interactions as well as being highly dependent on sex, age, and even the maternal environment. Although focused, reductionistic approaches have led to progress in elucidating the pathophysiology of cardiovascular diseases, such approaches are poorly powered to address complex interactions. Over the past decade, technological advances have made it possible to interrogate biological systems on a global level, raising hopes that, in combination with computational approaches, it may be possible to more fully address the complexities of cardiovascular diseases. In this Review, we provide an overview of such systems-based approaches to cardiovascular disease and discuss their translational implications.

Current use of pimobendan in canine patients with heart disease

Pimobendan is a drug with both inotropic and vasodilatory properties and is widely used for the treatment of heart failure in dogs. The best evidence regarding its efficacy is derived from several clinical studies of dogs with the two most common conditions that result in heart failure: dilated cardiomyopathy (DCM) and degenerative mitral valve disease (DMVD). The main studies addressing the effectiveness of pimobendan in dogs with DCM and DVMD are discussed in this article.

Genetics and genomics of stroke: novel approaches

Evidence for a genetic basis for stroke comes from twin and family studies and from the occurrence of a number of uncommon monogenic disorders, but the contribution of genetic factors identified for stroke so far is small. Advances in genetics and genomics may permit new insights. In recent genome-wide association studies, a number of single-nucleotide polymorphisms have been associated with specific stroke subtypes and major stroke risk factors such as diabetes and atrial fibrillation. These await replication. Studies of messenger ribonucleic acid expression have also shown promise for the development of genomic signatures for stroke classification. Stroke and coronary heart disease share some features of pathophysiology, risk, and treatment, and their genetic and genomic bases also appear to overlap.

Pharmacogenomics in thrombosis

Inherited or acquired genetic abnormalities play a major role in thromboembolic complications. The goal of pharmacogenomics is to tailor medications to an individual's genetic makeup in order to improve the benefit-to-risk ratio. Significant findings have been documented showing the effect of certain genetic variations (e.g., in CYP2C9 and VKORC1) on the dose response to warfarin. Pharmacogenomic and genetic information is crucial to improving the efficacy and safety of pharmacotherapy and for the optimal management of thromboembolic disorders.

Multi-organ expression profiling uncovers a gene module in coronary artery disease involving transendothelial migration of leukocytes and LIM domain binding 2: the Stockholm Atherosclerosis Gene Expression (STAGE) study

Environmental exposures filtered through the genetic make-up of each individual alter the transcriptional repertoire in organs central to metabolic homeostasis, thereby affecting arterial lipid accumulation, inflammation, and the development of coronary artery disease (CAD). The primary aim of the Stockholm Atherosclerosis Gene Expression (STAGE) study was to determine whether there are functionally associated genes (rather than individual genes) important for CAD development. To this end, two-way clustering was used on 278 transcriptional profiles of liver, skeletal muscle, and visceral fat (n = 66/tissue) and atherosclerotic and unaffected arterial wall (n = 40/tissue) isolated from CAD patients during coronary artery bypass surgery. The first step, across all mRNA signals (n = 15,042/12,621 RefSeqs/genes) in each tissue, resulted in a total of 60 tissue clusters (n = 3958 genes). In the second step (performed within tissue clusters), one atherosclerotic lesion (n = 49/48) and one visceral fat (n = 59) cluster segregated the patients into two groups that differed in the extent of coronary stenosis (P = 0.008 and P = 0.00015). The associations of these clusters with coronary atherosclerosis were validated by analyzing carotid atherosclerosis expression profiles. Remarkably, in one cluster (n = 55/54) relating to carotid stenosis (P = 0.04), 27 genes in the two clusters relating to coronary stenosis were confirmed (n = 16/17, P<10(-27 and-30)). Genes in the transendothelial migration of leukocytes (TEML) pathway were overrepresented in all three clusters, referred to as the atherosclerosis module (A-module). In a second validation step, using three independent cohorts, the A-module was found to be genetically enriched with CAD risk by 1.8-fold (P<0.004). The transcription co-factor LIM domain binding 2 (LDB2) was identified as a potential high-hierarchy regulator of the A-module, a notion supported by subnetwork analysis, by cellular and lesion expression of LDB2, and by the expression of 13 TEML genes in Ldb2-deficient arterial wall. Thus, the A-module appears to be important for atherosclerosis development and, together with LDB2, merits further attention in CAD research.

Genomic and personalized medicine: foundations and applications

The last decade has witnessed a steady embrace of genomic and personalized medicine by senior government officials, industry leadership, health care providers, and the public. Genomic medicine, which is the use of information from genomes and their derivatives (RNA, proteins, and metabolites) to guide medical decision making-is a key component of personalized medicine, which is a rapidly advancing field of health care that is informed by each person's unique clinical, genetic, genomic, and environmental information. As medicine begins to embrace genomic tools that enable more precise prediction and treatment disease, which include "whole genome" interrogation of sequence variation, transcription, proteins, and metabolites, the fundamentals of genomic and personalized medicine will require the development, standardization, and integration of several important tools into health systems and clinical workflows. These tools include health risk assessment, family health history, and clinical decision support for complex risk and predictive information. Together with genomic information, these tools will enable a paradigm shift to a comprehensive approach that will identify individual risks and guide clinical management and decision making, all of which form the basis for a more informed and effective approach to patient care. DNA-based risk assessment for common complex disease, molecular signatures for cancer diagnosis and prognosis, and genome-guided therapy and dose selection are just among the few important examples for which genome information has already enabled personalized health care along the continuum from health to disease. In addition, information from individual genomes, which is a fast-moving area of technological development, is spawning a social and information revolution among consumers that will undoubtedly affect health care decision making. Although these and other scientific findings are making their way from the genome to the clinic, the full application of genomic and personalized medicine in health care will require dramatic changes in regulatory and reimbursement policies as well as legislative protections for privacy for system-wide adoption. Thus, there are challenges from both a scientific and a policy perspective to personalized health care; however, they will be confronted and solved with the certainty that the science behind genomic medicine is sound and the practice of medicine that it informs is evidence based.

Use of personalized medicine in the selection of patients for renal transplantation: views of Quebec transplant physicians and referring nephrologists

AIM

To explore the views of physicians on the use of personalized medicine tools to develop a new method for selecting potential recipients of a renal allograft.

METHODS

A total of 22 semidirected interviews, using clinical case studies.

RESULTS

According to the participants, this method has several possible applications within renal transplantation (individualizing immunosuppressive therapy, help with decision making, and possibly with the selection of patients). It could be more effective than the method presently used. The method must be validated scientifically, and must also involve clinical judgment.

CONCLUSION

The use of personalized medicine within transplantation must be in the best interests of the patient. An ethical reflection is necessary in order to focus on the possibility of patients being excluded, as well as on the resolution of the equity/efficacy dilemma. Empirical research has shown itself to be essential for ascertaining the views of the clinicians who will be working with the tools provided by personalized medicine.

Using genetic information to select treatment for patients with heart failure: has the time come?

Personalized medicine is the concept of patient care becoming individualized based on distinctive characteristics. Pharmacogenetics is an application of personalized medicine, which may allow us to predict response to treatment based on an individual's genetic makeup. While several therapeutic areas have made significant advances in using pharmacogenetics to tailor therapies, it is not yet widely used in the treatment of heart failure. In this review, we summarize some of the emerging data on the use of pharmacogenetics in heart failure therapies.

Obstructive sleep apnea and cardiovascular disease: a perspective and future directions

Data from animal and human studies provide a biological plausibility to the notion that obstructive sleep apnea activates pathways that lead to insulin resistance, atherosclerosis and hypertension. Sleep apnea thus activates the same pathways as does obesity. That obstructive sleep apnea is a risk factor for cardiovascular disease is supported by epidemiological association studies. Longitudinal cohort studies also provide evidence that patients with untreated severe sleep apnea have an increased rate of cardiovascular events. But these studies, while highly suggestive, do not provide the evidence needed to convince the skeptic. This would only be obtained by randomized treatment trials with hard cardiovascular endpoints such as cardiac events and deaths. While such studies are in the planning stages, they will be challenging. There are issues about randomizing individuals with severe sleep apnea and excessive sleepiness into no therapy, since they are at known increased risk for car crashes. Thus, lack of therapy puts others on the road at risk as well as the subject with sleep apnea. There is, moreover, the concern that treating obstructive sleep apnea in very obese individuals will have little impact, since any effect of therapy for OSA will be overwhelmed by the effects of obesity itself. Data from randomized treatment trials for cardiovascular endpoints will likely not be available for many years. In the interim, physicians need to consider how to treat such patients. It is proposed that given that CPAP treatment for obstructive sleep apnea is highly effective and essentially totally safe, and that the evidence is suggestive that sleep apnea is a risk factor for cardiovascular disease, then we propose all patients with severe sleep apnea should be treated to reduce cardiovascular risk.

beta-adrenergic receptor gene polymorphisms and beta-blocker treatment outcomes in hypertension

Numerous studies have demonstrated that beta(1)- and beta(2)-adrenergic receptor gene (ADRB1 and ADRB2) variants influence cardiovascular risk and beta-blocker responses in hypertension and heart failure. We evaluated the relationship between ADRB1 and ADRB2 haplotypes, cardiovascular risk (death, nonfatal myocardial infarction (MI), and nonfatal stroke), and atenolol-based vs. verapamil sustained-release (SR)-based antihypertensive therapy in 5,895 coronary artery disease (CAD) patients. After an average of 2.8 years, death rates were higher in patients carrying the ADRB1 Ser49-Arg389 haplotype (hazard ratio (HR) 3.66, 95% confidence interval (95% CI) 1.68-7.99). This mortality risk was significant in patients randomly assigned to verapamil SR (HR 8.58, 95% CI 2.06-35.8) but not atenolol (HR 2.31, 95% CI 0.82-6.55), suggesting a protective role for the beta-blocker. ADRB2 haplotype associations were divergent within the treatment groups but did not remain significant after adjustment for multiple comparisons. ADRB1 haplotype variation is associated with mortality risk, and beta-blockers may be preferred in subgroups of patients defined by ADRB1 or ADRB2 polymorphisms.

Incident coronary artery calcium among postmenopausal women

Recent studies have shown that individuals with 0 coronary artery calcium (CAC) scores have very low risk of coronary heart disease. In the Healthy Women Study, we evaluated development of new CAC among postmenopausal women (n=272) over a 6-year period, age 62 at the 1st and 68 at the 3rd electron beam tomography (EBT) examination. At the 1st EBT, 155 of 272 (57%) women had 0 CAC. By the 3rd, 56 (36%) of these women had developed new CAC, including 38 with >or=5 Agatston units. There was practically no regression from having CAC at the 1st EBT to no CAC at the 3rd EBT. The risk of developing new CAC over 6 years among women with 0 CAC on their 1st EBT was strongly and significantly related to presence of both aortic calcium and carotid plaque at the time of 1st EBT. Baseline premenopausal risk factors, age 47, apolipoprotein B, body mass index (BMI) and triglycerides, were significant predictors of incident CAC as were the changes in BMI and low density lipoprotein cholesterol between premenopause and the 1st post exam, age 53. Risk factors measured premenopause and change in risk factors from premenopause to the 1st post exam and the extent of subclinical disease in other vascular beds are primary determinants of the risk of developing incident CAC in women over a 6-year period.

Genome-wide association study for subclinical atherosclerosis in major arterial territories in the NHLBI's Framingham Heart Study

INTRODUCTION

Subclinical atherosclerosis (SCA) measures in multiple arterial beds are heritable phenotypes that are associated with increased incidence of cardiovascular disease. We conducted a genome-wide association study (GWAS) for SCA measurements in the community-based Framingham Heart Study.

METHODS

Over 100,000 single nucleotide polymorphisms (SNPs) were genotyped (Human 100K GeneChip, Affymetrix) in 1345 subjects from 310 families. We calculated sex-specific age-adjusted and multivariable-adjusted residuals in subjects tested for quantitative SCA phenotypes, including ankle-brachial index, coronary artery calcification and abdominal aortic calcification using multi-detector computed tomography, and carotid intimal medial thickness (IMT) using carotid ultrasonography. We evaluated associations of these phenotypes with 70,987 autosomal SNPs with minor allele frequency > or = 0.10, call rate > or = 80%, and Hardy-Weinberg p-value > or = 0.001 in samples ranging from 673 to 984 subjects, using linear regression with generalized estimating equations (GEE) methodology and family-based association testing (FBAT). Variance components LOD scores were also calculated.

RESULTS

There was no association result meeting criteria for genome-wide significance, but our methods identified 11 SNPs with p < 10(-5) by GEE and five SNPs with p < 10(-5) by FBAT for multivariable-adjusted phenotypes. Among the associated variants were SNPs in or near genes that may be considered candidates for further study, such as rs1376877 (GEE p < 0.000001, located in ABI2) for maximum internal carotid artery IMT and rs4814615 (FBAT p = 0.000003, located in PCSK2) for maximum common carotid artery IMT. Modest significant associations were noted with various SCA phenotypes for variants in previously reported atherosclerosis candidate genes, including NOS3 and ESR1. Associations were also noted of a region on chromosome 9p21 with CAC phenotypes that confirm associations with coronary heart disease and CAC in two recently reported genome-wide association studies. In linkage analyses, several regions of genome-wide linkage were noted, confirming previously reported linkage of internal carotid artery IMT on chromosome 12. All GEE, FBAT and linkage results are provided as an open-access results resource at http://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?id=phs000007 webcite.

CONCLUSION

The results from this GWAS generate hypotheses regarding several SNPs that may be associated with SCA phenotypes in multiple arterial beds. Given the number of tests conducted, subsequent independent replication in a staged approach is essential to identify genetic variants that may be implicated in atherosclerosis.

Taking cardiovascular genetic association studies to the next level

Genetic information is beginning to have a direct impact on patient care and it is important that cardiologists appreciate the value and approaches to associating genetic variation and health outcomes. Genetic associations should be based on compelling genetic and biological hypotheses and should be statistically sound so as to reduce the possibility of "false discovery" in the setting of testing multiple hypotheses. Study designs should clearly define cases and controls and measurement of phenotypes. Finally, findings should be replicated in at least 1 independent cohort. Consideration of these principles should provide insight into disease biology based on genetic findings and encourage their meaningful adoption into clinical practice.

Redefining Risk in Acute Coronary Syndromes Using Molecular Medicine

Acute coronary syndromes represent a complex phenotype involving the interplay of many elements. The risk of developing an acute coronary syndrome and related complications has been defined by variables such as age, diabetes, smoking history, serum creatine phosphokinase, or electrocardiographic findings. However, in the past 5 years the wide-scale acceptance of a protein--troponin--has changed the diagnostic profile. With advances in molecular medicine, this protein is a segue to a panel of molecular assays that will improve screening and tailored intervention. We expound upon some of these factors and the potential they may carry in changing clinical medicine.

Potential new risk factors for ischemic stroke: what is their potential?

BACKGROUND AND PURPOSE

About 60% to 80% of all ischemic strokes can be attributed to increasing blood pressure, blood cholesterol, cigarette smoking, carotid stenosis, and diabetes mellitus (atherosclerotic ischemic stroke), and atrial fibrillation and valvular heart disease (cardiogenic ischemic stroke). The aim of this review was to examine the potential role of other risk factors in the etiology of ischemic stroke.

SUMMARY OF REVIEW

About 10% to 20% of atherosclerotic ischemic strokes can probably be attributed to recently established, causal risk factors for ischemic heart disease: raised apoB/apoA 1 ratio, obesity, physical inactivity, pyschosocial stress and low fruit and vegetable intake. However, their causal role remains to be proven. The direct genetic contribution of any single gene towards ischemic stroke is likely to be modest and apply in selected patients only and in combination with environmental factors or via other epistatic (gene-gene or gene-environmental) effects.

CONCLUSIONS

Research resources should not be allocated disproportionately to emerging novel risk factors that may account for up to only 20% of all strokes at the expense of researching the determinants of the relatively few established causal factors that account for up to 80% of all strokes.