Aldosterone Synthase Promoter Polymorphism Predicts Outcome in African Americans With Heart Failure

Multivariable prognostic model for heart failure in Chinese Han population-based setting

Aims

The prognosis of heart failure (HF) depends on genetic predisposition, and recent studies have shown that impaired autophagy is involved in HF. This study was aimed to construct a prognostic model combining polygenetic background based on the autophagy pathway and other traditional risk factors (TRF) of HF prognosis.

Methods and results

Via re‐analysing the transcriptomic data of 50 failing and 14 non‐failing donors, differentially expressed autophagy‐related genes (ARGs) were chosen for further comparison and analysis with whole exome sequencing and follow‐up data of 1000 HF patients. By searching from reported articles, prognosis‐related polymorphisms were identified. ARGs and prognosis‐related polymorphisms were used to develop genetic risk score (GRS) and genetic risk factor (GRF), respectively. We compared the predictive power of five models [Model 1, GRS; Model 2, composite of TRF and N‐terminal B‐type natriuretic peptide (NT‐proBNP); Model 3, composite of TRF, NT‐proBNP, and GRS; Model 4, composite of TRF, NT‐proBNP, and GRF; and Model 5, composite of TRF, NT‐proBNP, GRF, and GRS] by applying receiver operating characteristic curves. Twenty‐four prognosis‐related polymorphisms were used to construct GRF and 11 variants among 48 differentially expressed ARGs associated with clinical outcomes of HF patients were applied for GRS. GRS was strongly associated with cardiac mortality of HF patients, independent of TRF and GRF (95% confidence interval 1.273–1.739, P = 5.78 × 10⁻⁷). Comparing with patients with lowest GRS tertile, those with highest tertile had higher risks of developing worse clinical outcomes (hazard ratio = 1.866; 95% confidence interval 1.352–2.575, P = 1.47 × 10⁻⁴). The discrimination power of the model including GRS, TRF, GRF, and NT‐proBNP is most considerable (area under curve = 0.777), especially in men, patients over 60, patients with hypertension, patients without diabetes or hyperlipidaemia.

Conclusions

The model combining autophagy‐related GRS, TRF, GRF, and NT‐proBNP performs well in distinguishing between worse‐prognosis and better‐prognosis HF patients, leading a promising strategy for HF treatment and HF prevention.

When the At-Risk Do Not Develop Heart Failure: Understanding Positive Deviance Among Postmenopausal African American and Hispanic Women

BACKGROUND

African American and Hispanic postmenopausal women have the highest risk for heart failure compared with other races, but heart failure prevalence is lower than expected in some national cohorts. It is unknown whether psychosocial factors are associated with lower risk of incident heart failure hospitalization among high-risk postmenopausal minority women.

METHODS AND RESULTS

Using the Women's Health Initiative Study, African American and US Hispanic women were classified as high-risk for incident heart failure hospitalization with 1 or more traditional heart failure risk factors and the highest tertile heart failure genetic risk scores. Positive psychosocial factors (optimism, social support, religion) and negative psychosocial factors (living alone, social strain, depressive symptoms) were measured using validated survey instruments at baseline. Adjusted subdistribution hazard ratios of developing heart failure hospitalization were determined with death as a competing risk. Positive deviance indicated not developing incident heart failure hospitalization with 1 or more risk factors and the highest tertile for genetic risk. Among 7986 African American women (mean follow-up of 16 years), 27.0% demonstrated positive deviance. Among high-risk African American women, optimism was associated with modestly reduced risk of heart failure hospitalization (subdistribution hazard ratio 0.94, 95% confidence interval 0.91-0.99), and social strain was associated with modestly increased risk of heart failure hospitalization (subdistribution hazard ratio 1.07, 95% confidence interval 1.02-1.12) in the initial models; however, no psychosocial factors were associated with heart failure hospitalization in fully adjusted analyses. Among 3341 Hispanic women, 25.1% demonstrated positive deviance. Among high-risk Hispanic women, living alone was associated with increased risk of heart failure hospitalization (subdistribution hazard ratio 1.97, 95% confidence interval 1.06-3.63) in unadjusted analyses; however, no psychosocial factors were associated with heart failure hospitalization in fully adjusted analyses.

CONCLUSIONS

Among postmenopausal African American and Hispanic women, a significant proportion remained free from heart failure hospitalization despite having the highest genetic risk profile and 1 or more traditional risk factors. No observed psychosocial factors were associated with incident heart failure hospitalization in high-risk African Americans and Hispanics. Additional investigation is needed to understand protective factors among high-risk African American and Hispanic women.

Understanding the Complexity of Heart Failure Risk and Treatment in Black Patients

Although care of patients with heart failure (HF) has improved in the past decade, important disparities in HF outcomes persist based on race/ethnicity. Age-adjusted HF-related cardiovascular disease death rates are higher for Black patients, particularly among young Black men and women whose rates of death are 2.6- and 2.97-fold higher, respectively, than White men and women. Similarly, the rate of HF hospitalization for Black men and women is nearly 2.5-fold higher when compared with Whites, with costs that are significantly higher in the first year after HF hospitalization. While the relative rate of HF hospitalization has improved for other race/ethnic minorities, the disparity in HF hospitalization between Black and White patients has not decreased during the last decade. Although access to care and socioeconomic status have been traditional explanations for the observed racial disparities in HF outcomes, contemporary data suggest that novel factors including genetic susceptibility as well as social determinants of health and implicit bias may play a larger role in health outcomes than previously appreciated. The purpose of this review is to describe the complex interplay of factors that influence racial disparities in HF incidence, prevalence, and disease severity, with a highlight on evolving knowledge that will impact the clinical care and address future research needs to improve HF disparities in Blacks.

Addressing Social Determinants of Health in the Care of Patients With Heart Failure: A Scientific Statement From the American Heart Association

Heart failure is a clinical syndrome that affects >6.5 million Americans, with an estimated 550 000 new cases diagnosed each year. The complexity of heart failure management is compounded by the number of patients who experience adverse downstream effects of the social determinants of health (SDOH). These patients are less able to access care and more likely to experience poor heart failure outcomes over time. Many patients face additional challenges associated with the cost of complex, chronic illness management and must make difficult decisions about their own health, particularly when the costs of medications and healthcare appointments are at odds with basic food and housing needs. This scientific statement summarizes the SDOH and the current state of knowledge important to understanding their impact on patients with heart failure. Specifically, this document includes a definition of SDOH, provider competencies, and SDOH assessment tools and addresses the following questions: (1) What models or frameworks guide healthcare providers to address SDOH? (2) What are the SDOH affecting the delivery of care and the interventions addressing them that affect the care and outcomes of patients with heart failure? (3) What are the opportunities for healthcare providers to address the SDOH affecting the care of patients with heart failure? We also include a case study ( Data Supplement ) that highlights an interprofessional team effort to address and mitigate the effects of SDOH in an underserved patient with heart failure.

Pharmacological interventions for heart failure in people with chronic kidney disease

BACKGROUND

Approximately half of people with heart failure have chronic kidney disease (CKD). Pharmacological interventions for heart failure in people with CKD have the potential to reduce death (any cause) or hospitalisations for decompensated heart failure. However, these interventions are of uncertain benefit and may increase the risk of harm, such as hypotension and electrolyte abnormalities, in those with CKD.

OBJECTIVES

This review aims to look at the benefits and harms of pharmacological interventions for HF (i.e., antihypertensive agents, inotropes, and agents that may improve the heart performance indirectly) in people with HF and CKD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies through 12 September 2019 in consultation with an Information Specialist and using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials of any pharmacological intervention for acute or chronic heart failure, among people of any age with chronic kidney disease of at least three months duration.

DATA COLLECTION AND ANALYSIS

Two authors independently screened the records to identify eligible studies and extracted data on the following dichotomous outcomes: death, hospitalisations, worsening heart failure, worsening kidney function, hyperkalaemia, and hypotension. We used random effects meta-analysis to estimate treatment effects, which we expressed as a risk ratio (RR) with 95% confidence intervals (CI). We assessed the risk of bias using the Cochrane tool. We applied the GRADE methodology to rate the certainty of evidence.

MAIN RESULTS

One hundred and twelve studies met our selection criteria: 15 were studies of adults with CKD; 16 studies were conducted in the general population but provided subgroup data for people with CKD; and 81 studies included individuals with CKD, however, data for this subgroup were not provided. The risk of bias in all 112 studies was frequently high or unclear. Of the 31 studies (23,762 participants) with data on CKD patients, follow-up ranged from three months to five years, and study size ranged from 16 to 2916 participants. In total, 26 studies (19,612 participants) reported disaggregated and extractable data on at least one outcome of interest for our review and were included in our meta-analyses. In acute heart failure, the effects of adenosine A1-receptor antagonists, dopamine, nesiritide, or serelaxin on death, hospitalisations, worsening heart failure or kidney function, hyperkalaemia, hypotension or quality of life were uncertain due to sparse data or were not reported. In chronic heart failure, the effects of angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB) (4 studies, 5003 participants: RR 0.85, 95% CI 0.70 to 1.02; I² = 78%; low certainty evidence), aldosterone antagonists (2 studies, 34 participants: RR 0.61 95% CI 0.06 to 6.59; very low certainty evidence), and vasopressin receptor antagonists (RR 1.26, 95% CI 0.55 to 2.89; 2 studies, 1840 participants; low certainty evidence) on death (any cause) were uncertain. Treatment with beta-blockers may reduce the risk of death (any cause) (4 studies, 3136 participants: RR 0.69, 95% CI 0.60 to 0.79; I² = 0%; moderate certainty evidence). Treatment with ACEi or ARB (2 studies, 1368 participants: RR 0.90, 95% CI 0.43 to 1.90; I² = 97%; very low certainty evidence) had uncertain effects on hospitalisation for heart failure, as treatment estimates were consistent with either benefit or harm. Treatment with beta-blockers may decrease hospitalisation for heart failure (3 studies, 2287 participants: RR 0.67, 95% CI 0.43 to 1.05; I² = 87%; low certainty evidence). Aldosterone antagonists may increase the risk of hyperkalaemia compared to placebo or no treatment (3 studies, 826 participants: RR 2.91, 95% CI 2.03 to 4.17; I² = 0%; low certainty evidence). Renin inhibitors had uncertain risks of hyperkalaemia (2 studies, 142 participants: RR 0.86, 95% CI 0.49 to 1.49; I² = 0%; very low certainty). We were unable to estimate whether treatment with sinus node inhibitors affects the risk of hyperkalaemia, as there were few studies and meta-analysis was not possible. Hyperkalaemia was not reported for the CKD subgroup in studies investigating other therapies. The effects of ACEi or ARB, or aldosterone antagonists on worsening heart failure or kidney function, hypotension, or quality of life were uncertain due to sparse data or were not reported. Effects of anti-arrhythmic agents, digoxin, phosphodiesterase inhibitors, renin inhibitors, sinus node inhibitors, vasodilators, and vasopressin receptor antagonists were very uncertain due to the paucity of studies.

AUTHORS' CONCLUSIONS

The effects of pharmacological interventions for heart failure in people with CKD are uncertain and there is insufficient evidence to inform clinical practice. Study data for treatment outcomes in patients with heart failure and CKD are sparse despite the potential impact of kidney impairment on the benefits and harms of treatment. Future research aimed at analysing existing data in general population HF studies to explore the effect in subgroups of patients with CKD, considering stage of disease, may yield valuable insights for the management of people with HF and CKD.

Effect of Genetic and Nongenetic Factors on the Clinical Response to Mineralocorticoid Receptor Antagonist Therapy in Egyptians with Heart Failure

This prospective cohort study evaluated the association between the renin angiotensin aldosterone system genotypes and response to spironolactone in 155 Egyptian patients with heart failure with reduced ejection fraction (HFrEF). Genotype frequencies for AGT rs699 were: CC = 16%, CT = 48%, and TT = 36%. Frequencies for CYP11B2 rs1799998 were: TT = 33%, TC = 50%, and CC = 17%. After 6 months of spironolactone treatment, change in the left ventricular ejection fraction (LVEF) differed by AGT rs699 (CC, 14.6%; TC, 7.9%; TT, 2.7%; P = 2.1E‐26), and CYP11B2 rs1799998 (TT, 9.1%; TC, 8.7%; CC, 1.4%; P = 0.0006) genotypes. Multivariate linear regression showed that the AGT rs699 and CYP11B2 rs1799998 polymorphisms plus baseline serum potassium explained 71% of variability in LVEF improvement (P = 0.001), 63% of variability in serum potassium increase (P = 2.25E‐08), and 39% of the variability in improvement in quality of life (P = 2.3E‐04) with spironolactone therapy. These data suggest that AGT and CYP11B2 genotypes as well as baseline serum K are predictors of spironolactone response in HFrEF.

Association of Variants in BAG3 With Cardiomyopathy Outcomes in African American Individuals

Importance

The prevalence of nonischemic dilated cardiomyopathy (DCM) is greater in individuals of African ancestry than in individuals of European ancestry. However, little is known about whether the difference in prevalence or outcomes is associated with functional genetic variants.

Objective

We hypothesized that Bcl2-associated anthanogene 3 (BAG3) genetic variants were associated with outcomes in individuals of African ancestry with DCM.

Design

This multicohort study of the BAG3 genotype in patients of African ancestry with dilated cardiomyopathy uses DNA obtained from African American individuals enrolled in 3 clinical studies: the Genetic Risk Assessment of African Americans With Heart Failure (GRAHF) study; the Intervention in Myocarditis and Acute Cardiomyopathy Trial-2 (IMAC-2) study; and the Genetic Risk Assessment of Cardiac Events (GRACE) study. Samples of DNA were also acquired from the left ventricular myocardium of patients of African ancestry who underwent heart transplant at the University of Colorado and University of Pittsburgh.

Main Outcomes and Measures

The primary end points were the prevalence of BAG3 mutations in African American individuals and event-free survival in participants harboring functional BAG3 mutations.

Results

Four BAG3 genetic variants were identified; these were expressed in 42 of 402 African American individuals (10.4%) with nonischemic heart failure and 9 of 107 African American individuals (8.4%) with ischemic heart failure but were not present in a reference population of European ancestry (P < .001). The variants included 2 nonsynonymous single-nucleotide variants; 1 three-nucleotide in-frame insertion; and 2 single-nucleotide variants that were linked in cis. The presence of BAG3 variants was associated with a nearly 2-fold (hazard ratio, 1.97 [95% CI, 1.19-3.24]; P = .01) increase in cardiac events in carriers compared with noncarriers. Transfection of transformed adult human ventricular myocytes with plasmids expressing the 4 variants demonstrated that each variant caused an increase in apoptosis and a decrease in autophagy when samples were subjected to the stress of hypoxia-reoxygenation.

Conclusions and Relevance

This study demonstrates that genetic variants in BAG3 found almost exclusively in individuals of African ancestry were not causative of disease but were associated with a negative outcome in patients with a dilated cardiomyopathy through modulation of the function of BAG3. The results emphasize the importance of biological differences in causing phenotypic variance across diverse patient populations, the need to include diverse populations in genetic cohorts, and the importance of determining the pathogenicity of genetic variants.

A common variant alters SCN5A-miR-24 interaction and associates with heart failure mortality

SCN5A encodes the voltage-gated Na+ channel NaV1.5 that is responsible for depolarization of the cardiac action potential and rapid intercellular conduction. Mutations disrupting the SCN5A coding sequence cause inherited arrhythmias and cardiomyopathy, and single-nucleotide polymorphisms (SNPs) linked to SCN5A splicing, localization, and function associate with heart failure-related sudden cardiac death. However, the clinical relevance of SNPs that modulate SCN5A expression levels remains understudied. We recently generated a transcriptome-wide map of microRNA (miR) binding sites in human heart, evaluated their overlap with common SNPs, and identified a synonymous SNP (rs1805126) adjacent to a miR-24 site within the SCN5A coding sequence. This SNP was previously shown to reproducibly associate with cardiac electrophysiological parameters, but was not considered to be causal. Here, we show that miR-24 potently suppresses SCN5A expression and that rs1805126 modulates this regulation. We found that the rs1805126 minor allele associates with decreased cardiac SCN5A expression and that heart failure subjects homozygous for the minor allele have decreased ejection fraction and increased mortality, but not increased ventricular tachyarrhythmias. In mice, we identified a potential basis for this in discovering that decreased Scn5a expression leads to accumulation of myocardial reactive oxygen species. Together, these data reiterate the importance of considering the mechanistic significance of synonymous SNPs as they relate to miRs and disease, and highlight a surprising link between SCN5A expression and nonarrhythmic death in heart failure.

Cardiovascular Health in African Americans: A Scientific Statement From the American Heart Association

BACKGROUND AND PURPOSE

Population-wide reductions in cardiovascular disease incidence and mortality have not been shared equally by African Americans. The burden of cardiovascular disease in the African American community remains high and is a primary cause of disparities in life expectancy between African Americans and whites. The objectives of the present scientific statement are to describe cardiovascular health in African Americans and to highlight unique considerations for disease prevention and management.

METHOD

The primary sources of information were identified with PubMed/Medline and online sources from the Centers for Disease Control and Prevention.

RESULTS

The higher prevalence of traditional cardiovascular risk factors (eg, hypertension, diabetes mellitus, obesity, and atherosclerotic cardiovascular risk) underlies the relatively earlier age of onset of cardiovascular diseases among African Americans. Hypertension in particular is highly prevalent among African Americans and contributes directly to the notable disparities in stroke, heart failure, and peripheral artery disease among African Americans. Despite the availability of effective pharmacotherapies and indications for some tailored pharmacotherapies for African Americans (eg, heart failure medications), disease management is less effective among African Americans, yielding higher mortality. Explanations for these persistent disparities in cardiovascular disease are multifactorial and span from the individual level to the social environment.

CONCLUSIONS

The strategies needed to promote equity in the cardiovascular health of African Americans require input from a broad set of stakeholders, including clinicians and researchers from across multiple disciplines.

Ethnicity in Pulmonary Arterial Hypertension: Possibilities for Novel Phenotypes in the Age of Personalized Medicine

In the past decade and a half, the introduction of new therapeutic agents has revolutionized the management of pulmonary arterial hypertension (PAH). These new treatment options have improved the quality of life and survival in PAH. With an armamentarium of options available, the identification of unique phenotypes can help practitioners choose tailored treatment regimens. Experts in other cardiovascular diseases, such as congestive heart failure and hypertension, have recommended race-specific treatments in their fields based on data highlighting variations in response to therapies. With this perspective, we review evidence supporting the hypothesis that ethnicity or race plays an important role in the management of PAH. Preliminary research suggests that races/ethnicities have differences in the presentation and outcome of PAH and could respond to PAH-specific medications with varying efficacy. Genetic, physiological, and anatomic differences exist between races, particularly regarding the structure and function of the right ventricle. Unfortunately, clinical trials have not adequately included minorities, and registry data often omit inclusion of this demographic information. Further studies are needed to characterize the role that ethnicity plays in the prevalence, presentation, outcomes, and optimal treatment of PAH.

Circulating MicroRNA in patients with repaired tetralogy of Fallot

BACKGROUND

Emerging data suggest that heart-related microRNAs (miRs) may serve as circulating biomarkers of myocardial injury. We aimed to determine the circulating profile of miRs in patients with volume-overloaded right ventricles after repair of tetralogy (TOF).

MATERIALS AND METHODS

A total of 104 TOF patients and 70 controls were recruited. The study was conducted in two phases: (1) determination of circulating heart-related miRs described in left heart diseases (miR-1, miR-133a, miR-208a, miR-208b and miR423-5p) by quantitative real-time PCR in 49 patients and 30 controls and followed by validation in an independent cohort of 55 patients and 40 controls; (2) expression profiling of serum samples from eight patients and eight controls, followed by validation. Alteration in circulating miRNA expression was related to cardiac functional indices as assessed by 2D speckle tracking and 3D echocardiography.

RESULTS

No significant differences in serum levels of left heart-associated miRNAs were found between patients and controls. Of the candidate 19 miRNAs identified by profiling, upregulation of miR-99b and down-regulation of miR-766 were validated. However, no correlations were found between miRs levels and echo indices.

CONCLUSION

In young adults with repaired TOF and volume-overloaded right ventricles, circulating levels of miR-99b and miR-766, but not left heart-associated miRNAs, were significantly altered.

Towards Precision in HF Pharmacotherapy

PURPOSE OF REVIEW

Heart failure (HF) is a disease state with great heterogeneity, which complicates the therapeutic process. Identifying more precise HF phenotypes will allow for the development of more targeted therapies and improvement in patient outcomes. This review explores the future for precision medicine in HF treatment.

RECENT FINDINGS

Rather than a continuous disease spectrum with a uniform pathogenesis, HF has phenotypes with different underlying pathophysiologic features. The challenge is to establish clinical phenotypic characterizations to direct therapy. Phenomapping, a process of using machine learning algorithms applied to clinical data sets, has been used to identify phenotypically distinct and clinically meaningful HF groups. As powerful technologies extend our knowledge, future analyses may be able to compile more comprehensive phenotypic profiles using genetic, epigenetic, proteomic, and metabolomic measurements. Identifying clinical characterizations of particular HF patients that would be uniquely or disproportionately responsive to a specific treatment would allow for more direct selection of optimal therapy, reduce trial-and-error prescribing, and help avoid adverse drug reactions.

Combination of Hydralazine and Isosorbide-Dinitrate in the Treatment of Patients with Heart Failure with Reduced Ejection Fraction

The use of direct acting vasodilators (the combination of hydralazine and isosorbide dinitrate -Hy+ISDN-) in heart failure with reduced ejection fraction (HFrEF) is supported by evidence, but rarely used.However, treatment with Hy+ISDN is guideline-recommended for HFrEF patients who cannot receive either angiotensin-converting enzyme inhibitors or angiotensin receptor blockers due to intolerance or contraindication, and in self-identified African-American HFrEF patients who are symptomatic despite optimal neurohumoral therapy.The Hy+ISDN combination has arterial and venous vasodilating properties. It can decrease preload and afterload, decrease left ventricular end-diastolic diameter and the volume of mitral regurgitation, reduce left atrial and left ventricular wall tension, decrease pulmonary artery pressure and pulmonary arterial wedge pressure, increase stroke volume, and improve left ventricular ejection fraction, as well as induce left ventricular reverse remodelling. Furthermore, Hy+ISDN combination has antioxidant property, it affects endothelial dysfunction beneficially and improves NO bioavailability. Because of these benefits, this combination can improve the signs and symptoms of heart failure, exercise capacity and quality of life, and, most importantly, reduce morbidity and mortality in well-defined subgroups of HFrEF patients.Accordingly, this therapeutic option can in many cases play an essential role in the treatment of HFrEF.

Pharmacogenomics of heart failure: a systematic review

BACKGROUND

Heart failure (HF) and multiple HF-related phenotypes are heritable. Genes implicated in the HF pathophysiology would be expected to influence the response to treatment.

METHODS

We conducted a series of systematic literature searches on the pharmacogenetics of HF therapy to assess the current knowledge on this field.

RESULTS

Existing data related to HF pharmacogenomics are still limited. The ADRB1 gene is a likely candidate to predict response to β-blockers. Moreover, the cytochrome P450 2D6 coding gene (CYP2D6) clearly affects the pharmacokinetics of metoprolol, although the clinical impact of this association remains to be established.

CONCLUSION

Given the rising prevalence of HF and related costs, a more personalized use of HF drugs could have a remarkable benefit for patients, caregivers and healthcare systems.

Pharmacogenomics and pharmacogenetics for the intensive care unit: a narrative review

PURPOSE

Knowledge of how alterations in pharmacogenomics and pharmacogenetics may affect drug therapy in the intensive care unit (ICU) has received little study. We review the clinically relevant application of pharmacogenetics and pharmacogenomics to drugs and conditions encountered in the ICU.

SOURCE

We selected relevant literature to illustrate the important concepts contained within.

PRINCIPAL FINDINGS

Two main approaches have been used to identify genetic abnormalities - the candidate gene approach and the genome-wide approach. Genetic variability in response to drugs may occur as a result of alterations of drug-metabolizing (cytochrome P [CYP]) enzymes, receptors, and transport proteins leading to enhancement or delay in the therapeutic response. Of relevance to the ICU, genetic variation in CYP-450 isoenzymes results in altered effects of midazolam, fentanyl, morphine, codeine, phenytoin, clopidogrel, warfarin, carvedilol, metoprolol, HMG-CoA reductase inhibitors, calcineurin inhibitors, non-steroidal anti-inflammatory agents, proton pump inhibitors, and ondansetron. Changes in cholinesterase enzyme function may affect the disposition of succinylcholine, benzylisoquinoline muscle relaxants, remifentanil, and hydralazine. Genetic variation in transport proteins leads to differences in the response to opioids and clopidogrel. Polymorphisms in drug receptors result in altered effects of β-blockers, catecholamines, antipsychotic agents, and opioids. Genetic variation also contributes to the diversity and incidence of diseases and conditions such as sepsis, malignant hyperthermia, drug-induced hypersensitivity reactions, cardiac channelopathies, thromboembolic disease, and congestive heart failure.

CONCLUSION

Application of pharmacogenetics and pharmacogenomics has seen improvements in drug therapy. Ongoing study and incorporation of these concepts into clinical decision making in the ICU has the potential to affect patient outcomes.

Practical Pharmacogenomic Approaches to Heart Failure Therapeutics

OPINION STATEMENT

The major challenge in applying pharmacogenomics to everyday clinical practice in heart failure (HF) is based on (1) a lack of robust clinical evidence for the differential utilization of neurohormonal antagonists in the management of HF in different subgroups, (2) inconsistent results regarding appropriate subgroups that may potentially benefit from an alternative strategy based on pharmacogenomic analyses, and (3) a lack of clinical trials that focused on testing gene-guided treatment in HF. To date, all pharmacogenomic analyses in HF have been conducted as post hoc retrospective analyses of clinical trial data or of observational patient series studies. This is in direct contrast with the guideline-directed HF therapies that have demonstrated their safety and efficacy in the absence of pharmacogenomic guidance. Therefore, the future of clinical applications of pharmacogenomic testing will largely depend on our ability to incorporate gene-drug interactions into the prescribing process, requiring that preemptive and cost-effective testing be paired with decision-support tools in a value-based care approach.

GNB3 C825T Polymorphism and Myocardial Recovery in Peripartum Cardiomyopathy: Results of the Multicenter Investigations of Pregnancy-Associated Cardiomyopathy Study

BACKGROUND

Black women are at greater risk for peripartum cardiomyopathy (PPCM). The guanine nucleotide-binding proteins β-3 subunit (GNB3) has a polymorphism C825T. The GNB3 TT genotype more prevalent in blacks is associated with poorer outcomes. We evaluated GNB3 genotype and myocardial recovery in PPCM.

METHODS AND RESULTS

A total of 97 women with PPCM were enrolled and genotyped for the GNB3 T/C polymorphism. Left ventricular ejection fraction (LVEF) was assessed by echocardiography at entry, 6 and 12 months postpartum. LVEF over time in subjects with the GNB3 TT genotype was compared with those with the C allele overall and in black and white subsets. The cohort was 30% black, age 30+6, LVEF 0.34+0.10 at entry 31+25 days postpartum. The % GNB3 genotype for TT/CT/CC=23/41/36 and differed markedly by race (blacks=52/38/10 versus whites=10/44/46, P<0.001). In subjects with the TT genotype, LVEF at entry was lower (TT=0.31+0.09; CT+CC=0.35+0.09, P=0.054) and this difference increased at 6 (TT=0.45+0.15; CT+CC=0.53+0.08, P=0.002) and 12 months (TT=0.45+0.15; CT+CC=0.56+0.07, P<0.001.). The difference in LVEF at 12 months by genotype was most pronounced in blacks (12 months LVEF for GNB3 TT=0.39+0.16; versus CT+CC=0.53+0.09, P=0.02) but evident in whites (TT=0.50++0.11; CT+CC=0.56+0.06, P=0.04).

CONCLUSIONS

The GNB3 TT genotype was associated with lower LVEF at 6 and 12 months in women with PPCM, and this was particularly evident in blacks. Racial differences in the prevalence and impact of GNB3 TT may contribute to poorer outcomes in black women with PPCM.

Aldosterone Synthase Promoter Polymorphism and Cardiovascular Phenotypes in a Large, Multiethnic Population-Based Study

BACKGROUND

A single-nucleotide polymorphism in the aldosterone synthase gene (CYP11B2) promoter [-344C/T, rs1799998] has been reported to associate with cardiovascular phenotypes.

METHODS

The Dallas Heart Study is a large, multiethnic cohort with a high prevalence of hypertension. We genotyped 3452 Dallas Heart Study participants for -344C/T. Generalized linear models were used to assess whether variation at -344C/T associated with plasma aldosterone concentration (PAC), systolic and diastolic blood pressure (SBP and DBP), plasma glucose (in persons with no diabetes), HOMA IR (Homeostasis Model Assessment as an Index of Insulin Resistance), and left ventricular (LV) mass indexed to height. Systolic blood pressure and DBP were significantly higher in blacks compared with whites (P < 0.001 for SBP and for DBP) and Hispanics (P < 0.001 for SBP and for DBP). Log-transformed body mass index was also significantly higher in blacks compared with whites (P < 0.001), but not Hispanics (P = 0.10). Log-transformed PAC was higher in whites compared with blacks (P < 0.001), but did not differ significantly in whites compared with Hispanics (P = 0.73). In univariate and multivariable analysis, -344C/T was not significantly associated with PAC within any ethnicity. In univariate and multivariable analysis, -344C/T was not associated with SBP or DBP within any ethnicity. After adjustment for multiple testing, univariate and multivariable analyses revealed no association between -344C/T and plasma glucose in patients with no diabetes, HOMA IR, or LV mass indexed to height.

CONCLUSIONS

We were unable to reproduce previously reported associations between -344C/T and PAC, blood pressure, plasma glucose, or LV mass. Methodological differences might explain the differences between our findings and those previously reported.

Refractory hyperaldosteronism in heart failure is associated with plasma renin activity and angiotensinogen polymorphism

AIMS

Refractory hyperaldosteronism is frequently observed in heart failure patients on up-to-date treatment, and holds prognostic value. Our aim was to identify which factors, either genetic or nongenetic, are associated with refractory hyperaldosteronism.

METHODS

We enrolled 109 consecutive patients with left ventricular systolic dysfunction [left ventricular ejection fraction (LVEF) 32 ± 10%; 86% males; age 65 ± 13 years (mean ± standard deviation)] on optimized adrenergic and renin-angiotensin-aldosterone system (RAAS) antagonism, undergoing clinical and neuroendocrine characterization, and genotyping for six polymorphisms in key RAAS-regulating genes [angiotensinogen (AGT M235T), angiotensin-converting enzyme (ACE-240A>T and I/D), angiotensin II type I receptor (AGTR1 1166A>C), aldosterone synthase (CYP11B2-344C>T) and renin (REN rs7539596)].

RESULTS

Patients with refractory hyperaldosteronism (n = 41, 38%, with plasma concentration >180 ng/l, URL, median 283 ng/l, interquartile range 218-433), when compared with those without (106 ng/l, 74-144; P < 0.001), were not different either for treatment or LVEF, while presented with different AGT M235T genotype distribution (P = 0.047). After adjustment for several humoral, instrumental, functional and therapeutical variables, only plasma renin activity (PRA) (P < 0.001) and potassium (P = 0.027) were independently associated with refractory hyperaldosteronism. Among polymorphisms, only AGT M235T (P = 0.038) was associated with refractory hyperaldosteronism, after adjustment for nongenetic variables.

CONCLUSIONS

In conclusion, refractory hyperaldosteronism in heart failure may be influenced by AGT M235T polymorphism, among RAAS candidate genes, and by PRA, which may represent, respectively, a constitutive (genotype dependent) and a nongenetic (phenotype-dependent) trigger for aldosterone elevation.

Relationship of Genetic Polymorphisms of Aldosterone Synthase Gene Cytochrome P450 11B2 and Mineralocorticoid Receptors with Coronary Artery Disease in Taiwan

The aldosterone synthase gene, cytochrome P450 11B2 (CYP11B2), and mineralocorticoid receptor (MR) genes have been reported to be associated with coronary artery disease (CAD). In this study, we investigated the association of single nucleotide polymorphisms (SNPs) of CYP11B2 (CYP11B2 T-344C) and MR (MR C3514G and MR C4582A) with CAD in Taiwanese. Six hundred and nine unrelated male and female subjects who received elective coronary angiography were recruited from Chung Shan Medical University Hospital. The enrolled subjects were those who had a positive noninvasive test. CYP11B2 T-344C, MR C3514G and MR C4582A were determined by polymerase chain reaction-restriction fragment length polymorphism. We found that women with CYP11B2 C/C had a higher risk of developing CAD. However, there were no significant differences in the genotype distributions of MR C3514G and MR C4582A between the women with and without CAD. In multivariate analysis, CYP11B2 T-344C was most significantly associated with CAD in Taiwanese women. In conclusions, CYP11B2 C/C was more significantly associated with the development of CAD than diabetes mellitus or hypertension. This implies that CYP11B2 C/C plays a more important role than some conventional risk factors in the development of CAD in Taiwanese women.

Genetic variants are not associated with outcome in patients with coronary artery disease and left ventricular dysfunction: results of the Genetic Substudy of the Surgical Treatment for Ischemic Heart Failure (STICH) trials

OBJECTIVES AND BACKGROUND

We evaluated the ability of 23 genetic variants to provide prognostic information in patients enrolled in the Genetic Substudy of the Surgical Treatment for Ischemic Heart Failure (STICH) trials.

METHODS

Patients assigned to STICH Hypothesis 1 were randomized to medical therapy with or without coronary artery bypass grafting (CABG). Those assigned to STICH Hypothesis 2 were randomized to CABG or CABG with left ventricular reconstruction.

RESULTS

In patients assigned to STICH Hypothesis 2 (n = 714), no genetic variant met the prespecified Bonferroni-adjusted threshold for statistical significance (p < 0.002); however, several variants met nominal prognostic significance: variants in the β2-adrenergic receptor gene (β2-AR Gln27Glu) and in the A1-adenosine receptor gene (A1-717 T/G) were associated with an increased risk of a subject dying or being hospitalized for a cardiac problem (p = 0.027 and 0.031, respectively). These relationships remained nominally significant even after multivariable adjustment for prognostic clinical variables. However, none of the 23 genetic variants influenced all-cause mortality or the combination of death or cardiovascular hospitalization in the STICH Hypothesis 1 population (n = 532) by either univariate or multivariable analysis.

CONCLUSION

We were unable to identify the predictive genotypes in optimally treated patients in these two ischemic heart failure populations.

Race, common genetic variation, and therapeutic response disparities in heart failure

Because of its comparatively recent evolution, Homo sapiens exhibit relatively little within-species genomic diversity. However, because of genome size, a proportionately small amount of variation creates ample opportunities for both rare mutations that may cause disease as well as more common genetic variations that may be important in disease modification or pharmacogenetics. Primarily because of the East African origin of modern humans, individuals of African ancestry (AA) exhibit greater degrees of genetic diversity than more recently established populations, such as those of European ancestry (EA) or Asian ancestry. Those population effects extend to differences in frequency of common gene variants that may be important in heart failure natural history or therapy. For cell-signaling mechanisms important in heart failure, we review and present new data for genetic variation between AA and EA populations. Data indicate that: 1) neurohormonal signaling mechanisms frequently (16 of the 19 investigated polymorphisms) exhibit racial differences in the allele frequencies of variants comprising key constituents; 2) some of these differences in allele frequency may differentially affect the natural history of heart failure in AA compared with EA individuals; and 3) in many cases, these differences likely play a role in observed racial differences in drug or device response.

G-protein beta-3 subunit genotype predicts enhanced benefit of fixed-dose isosorbide dinitrate and hydralazine: results of A-HeFT

OBJECTIVES

The purpose of this study was to evaluate the influence of the guanine nucleotide-binding proteins (G-proteins), beta-3 subunit (GNB3) genotype on the effectiveness of a fixed-dose combination of isosorbide dinitrate and hydralazine (FDC I/H) in A-HeFT (African American Heart Failure Trial).

BACKGROUND

GNB3 plays a role in alpha2-adrenergic signaling. A polymorphism (C825T) exists, and the T allele is linked to enhanced alpha-adrenergic tone and is more prevalent in African Americans.

METHODS

A total of 350 subjects enrolled in the genetic substudy (GRAHF [Genetic Risk Assessment of Heart Failure in African Americans]) were genotyped for the C825T polymorphism. The impact of FDC I/H on a composite score (CS) that incorporated death, hospital stay for heart failure, and change in quality of life (QoL) and on event-free survival were assessed in GNB3 genotype subsets.

RESULTS

The GRAHF cohort was 60% male, 25% ischemic, 97% New York Heart Association functional class III, age 57 ± 13 years, with a mean qualifying left ventricular ejection fraction of 0.24 ± 0.06. For GNB3 genotype, 184 subjects were TT (53%), 137 (39%) CT, and 29 (8%) were CC. In GNB3 TT subjects, FDC I/H improved the CS (FDC I/H = 0.50 ± 1.6; placebo = -0.11 ± 1.8, p = 0.02), QoL (FDC I/H = 0.69 ± 1.4; placebo = 0.24 ± 1.5, p = 0.04), and event-free survival (hazard ratio: 0.51, p = 0.047), but not in subjects with the C allele (for CS, FDC I/H = -0.05 ± 1.7; placebo = -0.09 ± 1.7, p = 0.87; for QoL, FDC I/H = 0.28 ± 1.5; placebo = 0.14 ± 1.5, p = 0.56; and for event-free survival, p = 0.35).

CONCLUSIONS

The GNB3 TT genotype was associated with greater therapeutic effect of FDC I/H in A-HeFT. The role of the GNB3 genotype for targeting therapy with FDC I/H deserves further study.

Potential applications of pharmacogenomics to heart failure therapies

Pharmacogenomics explores one drug's varying effects on different patient genotypes. A better understanding of genomic variation's contribution to drug response can impact 4 arenas in heart failure (HF): (1) identification of patients most likely to receive benefit from therapy, (2) risk stratify patients for risk of adverse events, (3) optimize dosing of drugs, and (4) steer future clinical trial design and drug development. In this review, the authors explore the potential applications of pharmacogenomics in patients with HF in the context of these categories.

Use of isosorbide dinitrate and hydralazine in African-Americans with heart failure 9 years after the African-American Heart Failure Trial

The 2013 American College of Cardiology Foundation/American Heart Association guidelines recommend combined isosorbide dinitrate (ISDN) and hydralazine to reduce mortality and morbidity for African-Americans with symptomatic heart failure (HF) and reduced ejection fraction, currently receiving optimal medical therapy (class I, level A). Nitrates can alleviate HF symptoms, but continuous use is limited by tolerance. Hydralazine may mitigate nitrate tolerance, and the ISDN-hydralazine combination in the Vasodilators in Heart Failure Trial (V-HeFT) I improved survival and exercise tolerance in men with dilated cardiomyopathy or HF with reduced ejection fraction, most notably in self-identified black participants. In the subsequent V-HeFT II, survival was greater with enalapril than with ISDN-hydralazine in the overall cohort, but mortality rate was similar in the enalapril and ISDN-hydralazine groups in the self-identified black patients. Consequently, in the African-American Heart Failure Trial (A-HeFT) in self-identified black patients with symptomatic HF, adding a fixed-dose combination ISDN-hydralazine to modern guideline-based care improved outcomes versus placebo, including all-cause mortality, and led to early trial termination. Hypertension underlies HF, especially in African-Americans; the A-HeFT and its substudies demonstrated not only improvements in echocardiographic parameters, morbidity, and mortality but also a decrease in hospitalizations, potentially affecting burgeoning HF health-care costs. Genetic characteristics may, therefore, determine response to ISDN-hydralazine, and the Genetic Risk Assessment in Heart Failure substudy demonstrated important hypothesis-generating pharmacogenetic data.

Acute heart failure in the African American patient

BACKGROUND

African Americans (AAs) are disproportionately affected by acute heart failure (AHF) compared with other racial/ethnic groups. Disparities in AHF risk factors among AAs are attributed to higher rates of hypertension and diabetes mellitus, lower socioeconomic status, higher dietary caloric and salt intake, and biologic/genetic differences. However, AAs are frequently underrepresented in AHF clinical trials, and race-related differences in risks and clinical outcomes are not well understood.

OBJECTIVE

The aim of this work was to review published data on AHF in the AA population, including management strategies that may differ based on race and common barriers to optimal care.

METHODS

Publications were identified in Pubmed (through June 10, 2013) with the use of the search strategy terms (acute heart failure) AND (black OR African American OR racial).

RESULTS

Racial disparities in the quality of AHF care are relatively uncommon; however, racial differences in pathophysiology have resulted in differing pharmacologic recommendations (eg, isosorbide dinitrate plus hydralazine is indicated only in AAs). Various socioeconomic factors influence disease progression, treatment compliance, and hospitalization/rehospitalization rates.

CONCLUSIONS

Further research would enhance understanding of pathophysiologic heart failure differences between racial groups. Programs are needed that incorporate known clinical and cultural differences to improve quality of care and reduce the disease burden of AHF for all patients.

Race, exercise training, and outcomes in chronic heart failure: findings from Heart Failure - a Controlled Trial Investigating Outcomes in Exercise TraiNing (HF-ACTION)

BACKGROUND

The strength of race as an independent predictor of long-term outcomes in a contemporary chronic heart failure (HF) population and its association with exercise training response have not been well established. We aimed to investigate the association between race and outcomes and to explore interactions with exercise training in patients with ambulatory HF.

METHODS

We performed an analysis of HF-ACTION, which randomized 2331 patients with HF having an ejection fraction ≤35% to usual care with or without exercise training. We examined characteristics and outcomes (mortality/hospitalization, mortality, and cardiovascular mortality/HF hospitalization) by race using adjusted Cox models and explored an interaction with exercise training.

RESULTS

There were 749 self-identified black patients (33%). Blacks were younger with significantly more hypertension and diabetes, less ischemic etiology, and lower socioeconomic status versus whites. Blacks had shorter 6-minute walk distance and lower peak VO2 at baseline. Over a median follow-up of 2.5 years, black race was associated with increased risk for all outcomes except mortality. After multivariable adjustment, black race was associated with increased mortality/hospitalization (hazard ratio [HR] 1.16, 95% CI 1.01-1.33) and cardiovascular mortality/HF hospitalization (HR 1.46, 95% CI 1.20-1.77). The hazard associated with black race was largely caused by increased HF hospitalization (HR 1.58, 95% CI 1.27-1.96), given similar cardiovascular mortality. There was no interaction between race and exercise training on outcomes (P > .5).

CONCLUSIONS

Black race in patients with chronic HF was associated with increased prevalence of modifiable risk factors, lower exercise performance, and increased HF hospitalization, but not increased mortality or a differential response to exercise training.

Association of aldosterone synthase polymorphism (CYP11B2 -344T>C) and genetic ancestry with atrial fibrillation and serum aldosterone in African Americans with heart failure

The objective of this study was to examine the extent to which aldosterone synthase genotype (CYP11B2) and genetic ancestry correlate with atrial fibrillation (AF) and serum aldosterone in African Americans with heart failure. Clinical data, echocardiographic measurements, and a genetic sample for determination of CYP11B2 -344T>C (rs1799998) genotype and genetic ancestry were collected from 194 self-reported African Americans with chronic, ambulatory heart failure. Genetic ancestry was determined using 105 autosomal ancestry informative markers. In a sub-set of patients (n = 126), serum was also collected for determination of circulating aldosterone. The CYP11B2 -344C allele frequency was 18% among the study population, and 19% of patients had AF. Multiple logistic regression revealed that the CYP11B2 -344CC genotype was a significant independent predictor of AF (OR 12.7, 95% CI 1.60-98.4, p = 0.0150, empirical p = 0.011) while holding multiple clinical factors, left atrial size, and percent European ancestry constant. Serum aldosterone was significantly higher among patients with AF (p = 0.036), whereas increased West African ancestry was inversely correlated with serum aldosterone (r = -0.19, p = 0.037). The CYP11B2 -344CC genotype was also overrepresented among patients with extreme aldosterone elevation (≥90th percentile, p = 0.0145). In this cohort of African Americans with chronic ambulatory heart failure, the CYP11B2 -344T>C genotype was a significant independent predictor of AF while holding clinical, echocardiographic predictors, and genetic ancestry constant. In addition, increased West African ancestry was associated with decreased serum aldosterone levels, potentially providing an explanation for the lower risk for AF observed among African Americans.

Pharmacogenomics and heart failure in congenital heart disease

Congenital heart disease (CHD) constitutes a lifelong challenge in heart failure management. Current therapy is based mainly on physiologic principles extrapolated from the management of left ventricular failure in adult populations with either ischemic or nonischemic cardiomyopathy. However, there is good evidence of genomic variability in the origin and progression of CHD that suggests the need for a individualized approach to treatment. The developing science of pharmacogenomics presents an opportunity for CHD management broadly, and especially in the context of heart failure. There is growing evidence that individualizing drug therapy for these patients might be beneficial, and that prediction of response to therapy might be possible by incorporating genomic data into the treatment algorithm for individual patients.

Genetic prediction of heart failure incidence, prognosis and beta-blocker response

Heart failure (HF) is a widespread syndrome due to left ventricular dysfunction with high mortality, morbidity and health-care costs. Beta-blockers, together with diuretics and ACE-inhibitors or angiotensin receptor blockers, are a cornerstone of HF therapy, as they reduce mortality and morbidity. Nevertheless, their efficacy varies among patients, and genetics is likely to be one of the modifying factors. In this article, literature on the role of candidate genes on the development of HF, its prognosis and pharmacogenomics of β-blockers in patients with HF is reviewed. The available findings do not support, at the present time, a role for genetic tests in the treatment of HF. More large-scale genome-wide studies with adequate methodology and statistical analysis are required before considering genetic tailoring of HF therapy in patients with systolic HF.

Genetic variation in the renin-angiotensin-aldosterone system is associated with cardiovascular risk factors and early mortality in established coronary heart disease

This study examined renin-angiotensin-aldosterone (RAAS) system gene variants for associations with cardiovascular risk factors and outcomes in coronary heart disease. Coronary disease patients (n=1186) were genotyped for 21 single-nucleotide polymorphisms (SNPs) within angiotensinogen (AGT), angiotensin-converting enzyme (ACE), angiotensin-II type-1 receptor (AGTR1) and aldosterone synthase (CYP11B2). Associations with all-cause mortality and cardiovascular readmissions were assessed over a median of 3.0 years. The AGT M235T 'T' allele was associated with a younger age of clinical coronary disease onset (P=0.006), and the AGT rs2478545 minor allele was associated with lower circulating natriuretic peptides (P=0.0001-P=0.001) and E/E(1) (P=0.018). Minor alleles of AGT SNPs rs1926723 and rs11122576 were associated with more frequent history of renal disease (P0.04) and type-2 diabetes (P0.02), higher body mass index (P0.02) and greater mortality (P0.007). AGT rs11568054 minor allele carriers had more frequent history of renal disease (P=0.04) and higher plasma creatinine (P=0.033). AGT rs6687360 minor allele carriers exhibited worse survival (P=0.02). ACE rs4267385 was associated with older clinical coronary disease onset (P=0.008) and hypertension (P=0.013) onset, increased plasma creatinine (P=0.01), yet greater mortality (P=0.044). Less history of hypertension was observed with the AGTR1 rs12685977 minor allele (P=0.039). Genetic variation within the RAAS was associated with cardiovascular risk factors and accordingly poorer survival.

Pharmacogenetics in chronic heart failure: new developments and current challenges

The individual patient responses to chronic heart failure (HF) pharmacotherapies are highly variable. This variability cannot be entirely explained by clinical characteristics, and genetic variation may play a role. Therefore, this review will summarize the background pharmacogenetic literature for major HF pharmacotherapy classes (ie, β-blockers, angiotensin-converting enzyme inhibitors, digoxin, and loop diuretics), evaluate recent advances in the HF pharmacogenetic literature in the context of previous findings, and discuss the challenges and conclusions for HF pharmacogenetic data and its clinical application.

Pharmacogenetics in heart failure trials

There is ongoing research into potential pharmacogenetic targets in heart failure. Several challenges exist despite the potential benefits, and questions remain on the level of evidence needed to support product approval or labeling. High annual mortality, high morbidity, and heterogeneity of response to treatment underscore the need for predictability of response in this patient population. Although prime time testing and application of pharmacogenetics is not currently being used in heart failure, we believe this treatment approach is not too distant. The data are supportive, and further research is warranted to strengthen the approach.

Relationship between -344T/C polymorphism in the aldosterone synthase gene and atrial fibrillation in patients with essential hypertension

INTRODUCTION

Aldosterone plays an important role in the pathogenesis of non-familial atrial fibrillation (AF). We tested the hypothesis that the -344T/C polymorphism in the aldosterone synthase gene may be associated with non-familial AF in Chinese patients with hypertension.

MATERIALS AND METHODS

We performed a 1:1 paired case-control study in 310 cases of hypertension with AF and same number matched controls. The -344T/C polymorphism was determined with polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

The distribution of the CYP11B2 genotypes (TT, TC and CC) was 41.9%, 50.6%, and 7.4% in AF patients, which was not different from controls (48.4%, 44.5%, and 7.1%, χ(2) = 2.675, p = 0.263). The difference between the C allele (32.3% vs. 29.4%) was also not significant between two groups (χ(2) = 1.661, p = 0.197). Logistic regression analysis showed that LAD and LVEDD (both p < 0.001), rather than the C allele of the CYP11B2 gene (p= 0.107) were significant predictors for AF. The LAD of C allele carriers is significantly larger than that of non-C allele carriers (p = 0.009).

CONCLUSIONS

Our results indicate that the -344T/C polymorphism in the aldostrone synthase gene is not associated with AF but it might be associated with atrial remodelling in hypertensives.

Management of hypertension in high-risk ethnic minority with heart failure

Hypertension (HTN) is the most common co-morbidity in the world, and its sequelae, heart failure (HF) is one of most common causes of mortality and morbidity in the world. Current understanding of pathophysiology and management of HTN in HF is mainly based on studies, which have mainly included whites. Among racial groups, African-American adults have the highest rates (44%) of hypertension in the world and are more resistant to treatment. There is an emerging consensus on the significance of racial disparities in the pathophysiology and treatment options of hypertension and heart failure. However, African Americans had been underrepresented in all the trials until the initiation of the A-HEFT trial. Since the recognition of obstructive sleep apnea (OSA) as an important medical condition, large clinical trials have shown benefits of OSA treatment among patients with HTN and HF. This paper focuses on the pathophysiology, causes of secondary hypertension, and treatment of hypertension among African-American patients with heart failure. There is increasing need for randomized clinical trials testing innovative treatment options for African-American patients.

Future of personalized pharmacotherapy in chronic heart failure patients

There is a significant amount of diversity among heart failure (HF) patients. Contemporary HF regimens often do not take into consideration many of the factors that might influence an individual’s response to treatment. Clinical recommendations based on trial data derived from mainly younger Caucasian male study populations have, in most cases, been applied equally to women and African–Americans. Subgroup analyses of randomized HF trials and results of retrospective cohort studies have been used for customizing HF regimens in women and African–Americans. Pharmacogenetics is an emerging strategy for personalizing HF therapy. Genetic biomarkers may play an important role in predicting a patient’s response to treatment and in predicting those at risk of toxicity. HF pharmacotherapy has improved over the last two decades; however, substantial work remains in order to personalize HF management and maximize the benefit of pharmacologic interventions, while limiting adverse events.

Aldosterone Antagonists in Heart Failure

Aldosterone antagonists represented by nonselective spironolactone and mineralocorticoid-selective eplerenone are approved for treatment of symptomatic heart failure with reduced systolic function. Their cardioprotective, antifibrotic, and antiarrhythmic effects have been proven in animal experiments, and their effects on morbidity and mortality have been demonstrated in randomized clinical trials. Yet, they remain the most underutilized of all classes of medications for heart failure, primarily because of fear of hyperkalemia. Thorough patient screening and selection is the key for minimizing risks and optimizing benefits from these drugs. Ongoing trials will demonstrate whether the indication for aldosterone antagonists can be expanded to less severe heart failure or patients with preserved systolic function.

Does over-expression of transforming growth factor-beta account for the increased morbidity in African-Americans?: possible clinical study and therapeutic implications

African-Americans experience an excessive prevalence of a number of apparently disparate disorders that all appear to be, at least in part, mediated by the over-expression or activation of transforming growth factor-beta (TGF-beta) signaling pathways, and that certain genotypes including the codon 10 polymorphism occur more commonly among African-Americans and appears to predispose to these disorders. These disorders, fibrosing in nature, include hypertension, focal glomerulosclerosis, diabetic nephropathy, end stage renal disease, sarcoidosis, uterine leiomyoma, keloids, myocardial fibrosis, and glaucoma. The specific polymorphism for TGF-beta, codon 10, has been implicated in glomerulosclerosis and diabetic nephropathy as well as cardiac transplant rejection. Although TGF-beta over-expression is not the sole factor in these disorders, it is suggested that by designing future clinical studies that consider genomic differences in TGF-beta expression, a more complete understanding of these clinical disorders will be possible. A more thorough understanding of the genetic basis of disease will like promote improved therapeutic regimens and may help reduce the disparate health outcomes for African-Americans as well as improve treatment of individuals of various and diverse ethnic backgrounds.

RAAS and adrenergic genes in heart failure: Function, predisposition and survival implications

It is well appreciated that several neurohormones and signaling cascades are activated that promote long-term deterioration of cardiac function and structure. Activation of the renin-angiotensin-aldosterone system (RAAS) and the adrenergic system is closely related to heart failure. Common gene variants that encode neurohormonal, adrenergic and intracellular proteins have been demonstrated to modulate the course and consequences of heart failure. However, the literature is replete with conflicting results and it remains uncertain as to whether particular gene variants predispose heart failure. Therefore, the main purpose of this review was to discuss the effects of single nucleotide polymorphisms (SNPs) that are located in genes encoding elements of the RAAS and the adrenergic system on the predisposition to and survival from heart failure. Most studies indicate that common SNPs encoding elements of the RAAS and the adrenergic system do not predispose individuals to heart failure. Conversely, it has been demonstrated that ARB1 Arg389Gly, GRK5 Gln41Leu, ACE I/D, CYP11B2 C-344T and AGTR1 A+1166C modulate pharmacological responses and have a considerable impact on cardiac-related survival. It should not be expected, however, that a single polymorphism determines survival, given that multiple gene products and environmental factors contribute to the pathogenesis of heart failure. Therefore, future studies should consider the interaction effects of multiple genes in populations that are as homogeneous as possible with respect to environmental characteristics.

Genomic variation and neurohormonal intervention in heart failure

Neurohormonal activation is an important driver of heart-failure progression, and all pharmacologic interventions that improve heart-failure survival inhibit this systemic response to myocardial injury. Adrenergic stimulation of beta(1) receptors in the kidney results in the release of plasma renin, the conversion of peptide precursors to angiotensin II (a2), and ultimately the production of aldosterone. beta(1)-blockers, angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), and aldosterone receptor antagonists all act by inhibiting the activity of critical protein of this core pathway: the beta(1) receptor, ACE, the a2 receptor, and aldosterone synthase. Investigation of the pharmacogenetic interactions of the ACE D/I polymorphism and heart-failure therapy demonstrates the power of genomics to target therapeutics. This review explores how genetic variation in genes involved in neurohormonal activation influences heart-failure outcomes and the impact of pharmacotherapy.