Summary of the American Heart Association's scientific statement on the relevance of genetics and genomics for prevention and treatment of cardiovascular disease

Association of LDLR, TP53 and MMP9 Gene Polymorphisms With Atherosclerosis in a Malaysian Study Population

Preliminary research has shown that low density lipoprotein receptor (LDLR), tumor protein (TP53) and matrix metalloproteinase 9 (MMP9) genes expression levels were significantly increased in atherosclerosis coronary artery tissue (ACAT) compared to non-atherosclerotic coronary artery tissue (NCAT) samples. Thus, further investigation was carried out to study the association of LDLR, TP53 and MMP9 gene polymorphisms and the risk of developing atherosclerosis (ATH) in a Malaysian population. Single nucleotide polymorphisms of C88S, TP53 codon 72 and MMP9C>T were analyzed in 76 ACAT samples and 149 NCAT samples, representing cases and controls, respectively. In results, heterozygous CT genotype of MMP9C>T polymorphism was significantly higher in ACAT compared to NCAT samples (57.9% vs 27.5%, χ² = 19.758, df= 1, P < 0.05). The CT genotype was found to be significantly associated with the risk of developing ATH (OR = 3.622, 95% CI = 2.028-6.470). However, the distribution of the CT genotype in a healthy Malaysian study population was incomparable regardless of gender and ethnicity. The DNA sequencing results validated the C88S, TP53 codon 72, and MMP9C>T polymorphisms. In conclusion, the CT genotype of the MMP9-1562C>T polymorphism was found to have a strong association with the risk of developing ATH.

Use of the Corus® CAD Gene Expression Test for Assessment of Obstructive Coronary Artery Disease Likelihood in Symptomatic Non-Diabetic Patients

The determination of the underlying etiology of symptoms suggestive of obstructive coronary artery disease (CAD, ≥50% stenosis in a major coronary artery) is a common clinical challenge in both primary care and cardiology clinics. Usual care in low to medium risk patients often involves a family history, risk factor assessment, and then stress testing with or without non-invasive imaging. If positive, this is often followed by invasive coronary angiography (ICA). Despite extensive adoption of this usual care paradigm, more than 60% of patients referred for angiography do not have obstructive CAD. In order to robustly identify those symptomatic patients without obstructive CAD, who can avoid subsequent cardiac testing and look elsewhere for the cause of their symptoms, a recently described whole blood gene expression score (GES: Corus® CAD, CardioDx, Inc., Palo Alto, CA) has been developed and validated in two multi-center trials. This paper reviews the published literature and assessments by independent parties regarding the analytical and clinical validity as well as the clinical utility of the Corus® CAD test.

The evolution and refinement of traditional risk factors for cardiovascular disease

Traditional risk factors for cardiovascular disease such as systemic hypertension and hypercholesterolemia, all described more than half a century ago, are relatively few in number. Efforts to expand the epidemiologic canon have met with limited success because of the high hurdle of causality. Fortunately, another solution to current deficiencies in risk assessment-in particular, the underestimation of risk both before and after initiation of pharmacotherapy-may exist. Parallel to the investigation of novel biomarkers, such as high-sensitivity C-reactive protein, ongoing research has yielded improved metrics of known causative conditions. This evolution of traditional risk factors, heralded by measures such as ambulatory blood pressure, central hemodynamics, low density lipoprotein particle concentration, genetic testing, and "vascular age," may better address the detection gap in cardiovascular disease.

Sudden cardiac death: The larger problem... The larger genome

This perspective considers progress in understanding how genetic influences modulate susceptibility to lethal ventricular arrhythmias in cardiac patients and the population at large, as opposed to those with rare inherited arrhythmic conditions, such as the Long-QT and Brugada syndromes. It addresses largely unresolved issues, such as how important these effects may be and what we know of underlying mediators and pathways. Attention is given to newly revealed mechanisms of genomic function and the problem of identifying new susceptibility genes and targets useful in developing improved strategies for sudden death prevention.

Pharmacogenetics of heart failure: evidence, opportunities, and challenges for cardiovascular pharmacogenomics

Heart failure is a significant medical problem affecting more than five million people in the USA alone. Although clinical trials of pharmacological agents have demonstrated significant reductions in the relative risk of mortality across populations, absolute mortality remains high. In addition, individual variation in response is great. Some of this variation may be explained by genetic polymorphism. In this paper, we review the key studies to date in heart failure pharmacogenetics, setting this against a background of recent progress in the genetics of warfarin metabolism. Several polymorphisms that have supporting molecular and clinical data in the heart failure literature are reviewed, among them the beta1-adrenergic receptor variant Arg389Gly and the angiotensin converting enzyme gene insertion/deletion polymorphism. These variants and others are responsible for a fraction of the total variation seen in the treatment response to heart failure. With the dawn of the genomic age, further pharmacogenetic and new pharmacogenomic studies will advance our ability to tailor the treatment of heart failure.