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Genome-wide association studies (GWAS) and differential expression analyses have had limited success in finding genes that cause complex diseases such as heart failure (HF), a leading cause of death in the United States. This article proposes a new statistical approach that integrates GWAS and expression quantitative trait loci (eQTL) data to identify important HF genes. For such genes, genetic variations that perturb its expression are also likely to influence disease risk. The proposed method thus tests for the presence of simultaneous signals: SNPs that are associated with the gene’s expression as well as with disease. An analytic expression for the p-value is obtained, and the method is shown to be asymptotically adaptively optimal under certain conditions. It also allows the GWAS and eQTL data to be collected from different groups of subjects, enabling investigators to integrate public resources with their own data. Simulation experiments show that it can be more powerful than standard approaches and also robust to linkage disequilibrium between variants. The method is applied to an extensive analysis of HF genomics and identifies several genes with biological evidence for being functionally relevant in the etiology of HF. It is implemented in the R package ssa. Supplementary materials for this article are available online.

Aims To assess the haemodynamic effects of organic vs. inorganic nitrate administration among patients with heart failure with preserved ejection fraction (HFpEF). Methods and results We assessed carotid and aortic pressure–flow relations non-invasively before and after the administration of 0.4 mg of sublingual nitroglycerin (n = 26), and in a separate sub-study, in response to 12.9 mmoL of inorganic nitrate (n = 16). Nitroglycerin did not consistently reduce wave reflections arriving at the proximal aorta (change in real part of reflection coefficient, 1st harmonic: −0.09; P = 0.01; 2nd harmonic: −0.045, P = 0.16; 3rd harmonic: +0.087; P = 0.05), but produced profound vasodilatation in the carotid territory, with a significant reduction in systolic blood pressure (133.6 vs. 120.5 mmHg; P = 0.011) and a marked reduction in carotid bed vascular resistance (19 580 vs. 13 078 dynes · s/cm5; P = 0.001) and carotid characteristic impedance (3440 vs. 1923 dynes · s/cm5; P = 0.002). Inorganic nitrate, in contrast, consistently reduced wave reflections across the first three harmonics (change in real part of reflection coefficient, 1st harmonic: −0.12; P = 0.03; 2nd harmonic: −0.11, P = 0.01; 3rd harmonic: −0.087; P = 0.09) and did not reduce blood pressure, carotid bed vascular resistance, or carotid characteristic impedance (P = NS). Conclusions Nitroglycerin produces marked vasodilatation in the carotid circulation, with a pronounced reduction in blood pressure and inconsistent effects on central wave reflections. Inorganic nitrate, in contrast, produces consistent reductions in wave reflections, and unlike nitroglycerin, it does so without significant hypotension or cerebrovascular dilatation. These haemodynamic differences may underlie the different effects on exercise capacity and side effect profile of inorganic vs. organic nitrate in HFpEF.

Despite its established inter-individual variability, sildenafil has been the subject of only a few pharmacogenetic investigations, with limited data regarding the genetic modulators of its pharmacokinetics. We conducted a pharmacogenetic substudy of patients randomized to sildenafil (n = 85) in the RELAX trial, which investigated the impact of high-dose sildenafil in patients with heart failure with preserved left ventricular ejection fraction (HFpEF). In the overall population, the CYP3A4 inferred phenotype appeared associated with the dose-adjusted peak concentrations of sildenafil at week 12 and week 24 (adjusted P=0.045 for repeated measures analysis), although this P value did not meet our corrected significance threshold of 0.0167. In the more homogeneous Caucasian subgroup, this association was significant (adjusted P=0.0165 for repeated measures). Hence, CYP3A4 inferred phenotype is associated with peak sildenafil dose-adjusted concentrations in patients with HFpEF receiving high doses of sildenafil. The clinical impact of this association requires further investigation.

Endothelial function may be deranged in heart failure with preserved ejection fraction (HFpEF). Serum NO-derived metabolites (NO m ) might provide a biochemical surrogate of endothelial function in patients with heart failure (HF). We measured serum NO m in 415 participants in the Penn HF Study. Participants with HFpEF (n = 82) and those whose EF had recovered (Recovered-HF, n = 125) were matched 1:1 to heart failure with reduced ejection fraction (HFrEF) participants based on age, gender, race, tobacco use, and eGFR. Serum NO m levels were quantified after chemical reduction coupled with gas-phase chemiluminescence detection. After adjustment for matching covariates and BMI, HFpEF (34.5 μM; interquartile range [IQR] 25.0, 51.5) participants had lower NO m levels than HFrEF (41.0 μM; IQR 28.3, 58.0; ratio of HFpEF:HFrEF 0.82, 95% confidence interval [CI] 0.67 to 0.99; p = 0.04), which further decreased when adjusted for covariates that affect endothelial function (ratio 0.79, 95% CI 0.65 to 0.98; p = 0.03). There were no differences between HFrEF (34.0; IQR 25.3, 49.0) and matched Recovered-HF (36.0 μM; IQR 25.0, 55.0) or HFpEF and Recovered-HF. Age (+21%/10-year increase, p m in HFpEF, whereas age (+11%/10-year increase, p = 0.03), current tobacco use (+67%, p = 0.01), and eGFR (p = 0.01) associated with NO m in Recovered-HF. In conclusion, HFpEF participants have reduced NO m compared with HFrEF in this matched cohort. This might suggest either compromised endothelial function or poor dietary intake. Black race was associated with lower NO m in HFpEF.

Rationale: Lower NP (natriuretic peptide) levels may contribute to the development of cardiometabolic diseases. Blacks have lower NP levels than middle-aged and older white adults. A high-carbohydrate challenge causes an upregulation of a negative ANP regulator microRNA-425 ( miR-425 ), which reduces ANP (atrial-NP) levels in whites. Objectives: We designed a prospective trial to study racial differences in (1) NP levels among young adults, (2) NP response to a high-carbohydrate challenge, and (3) explore underlying mechanisms for race-based differences. Methods and Results: Healthy self-identified blacks and whites received 3 days of study diet followed by a high-carbohydrate challenge. Gene expression from whole blood RNA was assessed in the trial participants. Additionally, atrial and ventricular tissue samples from the Myocardial Applied Genomics Network repository were examined for NP system gene expression. Among 72 healthy participants, we found that B-type-NP, NT-proBNP (N-terminal-pro-B-type NP), and MRproANP (midregional-pro-ANP) levels were 30%, 47%, and 18% lower in blacks compared with whites ( P ≤0.01), respectively. The decrease in MRproANP levels in response to a high-carbohydrate challenge differed by race (blacks 23% [95% CI, 19%–27%] versus whites 34% [95% CI, 31%–38]; P interaction NPPA/NPPB ) or NP signaling ( NPR1 ) in atrial and ventricular tissues. NP processing ( corin ), clearance ( NPR3 ), and regulation ( miR-425 ) genes were ≈3.5-, ≈2.5-, and ≈2-fold higher in blacks than whites in atrial tissues, respectively. We also found a 2-and 8-fold higher whole blood RNA expression of gene encoding for Neprilysin ( MME ) and miR-425 among blacks than whites. Conclusions: Racial differences in NP levels are evident in young, healthy adults suggesting a state of NP deficiency exists in blacks. Impaired NP processing and clearance may contribute to race-based NP differences. Higher miR-425 levels in blacks motivate additional studies to understand differences in NP downregulation after physiological perturbations. Clinical Trial Registration: URL: https://clinicaltrials.gov/ct2/show/NCT03072602 . Unique identifier: NCT03072602.

Rationale: Cardiomyopathies are a major cause of heart failure and have a strong heritable component. Objective: Determine the role of both common and rare nonsynonymous genetic variation in hypertrophic (HCM) and dilated familial cardiomyopathy (DCM). Methods and Results: Whole genome sequencing was used to determine common and rare nonsynonymous genetic variation in familial cases of HCM (n=56) or DCM (n=71). Variation was evaluated in 102 cardiomyopathy genes routinely assayed in clinical and commercial gene testing panels. We used cardiac gene expression data from GTEx (Genotype-Tissue Expression database) to define additional genes expressed in the heart. The number of nonsynonymous single nucleotide variants (nsSNVs), the majority of which were missense variants, was correlated with echocardiographic measurements. Principal component analysis (PCA) of left ventricular measures separated HCM and DCM. Regression of the first principal component using all nonsynonymous single nucleotide variants (nsSNVs) in cardiomyopathy genes showed the number of nsSNVs predicted DCM but not HCM. DCM probability in the cohort significantly increased as the number of cardiomyopathy gene nsSNVs increased (p Conclusions: DCM subjects carry a greater burden of nsSNVs in cardiomyopathy genes. This genomic burden translates to impaired systolic cardiac function in DCM. In contrast, nsSNV burden in cardiomyopathy genes did not correlate with the probability or manifestation of left ventricular measures in HCM. These findings support a complex inheritance for DCM where increased variation in cardiomyopathy genes creates a genetic background that predisposes to DCM and increased disease severity. The distinct genetic landscapes of HCM and DCM suggest that greater genetic variation in cardiac genes provokes unfavorable ventricular remodeling with reduced systolic function.

Identifying genetic markers for heterogeneous complex diseases such as heart failure has been challenging, and may require prohibitively large cohort sizes in genome-wide association studies (GWAS) in order to meet genome-wide statistical significance. On the other hand, chromatin quantitative trait loci (QTL), elucidated by direct epigenetic profiling of specific human tissues, may contribute towards prioritising sub-threshold variants for disease-association. Here, we captured non-coding genetic variants by performing enhancer H3K27ac ChIP-seq in 70 human control and end-stage failing hearts, mapping out a comprehensive catalogue of 47,321 putative human heart enhancers. 3,897 differential acetylation peaks (FDR 5%) pointed to pathways altered in heart failure (HF). To identify cardiac histone acetylation QTLs (haQTLs), we regressed out confounding factors including HF disease status, and employed the G-SCI test to call out 1,680 haQTLs (FDR 10%). RNA-seq performed on the same heart samples proved a subset of haQTLs to have significant association also to gene expression (expression QTLs), either in cis (180), or through long range interactions (81), identified by Hi-C and Hi-ChIP performed on a subset of hearts. We validated 2 of the haQTLs through base editing to show that the presence of those SNPs indeed affects gene expression in human embryonic stem cells-derived cardiomyocytes. Furthermore, a concordant relationship between the gain or disruption of transcription factor (TF) binding motifs, inferred from alternative alleles at the haQTLs, implied a surprising direct association between these specific TF and local histone acetylation in human hearts. Finally, 62 unique loci were identified by colocalisation of haQTLs with heart-related GWAS datasets. Disease-association for these new loci may indeed be mediated through modification of H3K27-acetylation enrichment and their corresponding gene expression differences.

Heart failure (HF) is a leading cause of morbidity and mortality worldwide1. A small proportion of HF cases are attributable to monogenic cardiomyopathies and existing genome-wide association studies (GWAS) have yielded only limited insights, leaving the observed heritability of HF largely unexplained2–4. We report the largest GWAS meta-analysis of HF to-date, comprising 47,309 cases and 930,014 controls. We identify 12 independent variant associations with HF at 11 genomic loci, all of which demonstrate one or more associations with coronary artery disease (CAD), atrial fibrillation, or reduced left ventricular function suggesting shared genetic aetiology. Expression quantitative trait analysis of non-CAD-associated loci implicate genes involved in cardiac development (MYOZ1, SYNPO2L), protein homeostasis (BAG3), and cellular senescence (CDKN1A). Using Mendelian randomisation analysis we provide new evidence supporting previously equivocal causal roles for several HF risk factors identified in observational studies, and demonstrate CAD-independent effects for atrial fibrillation, body mass index, hypertension and triglycerides. These findings extend our knowledge of the genes and pathways underlying HF and may inform the development of new therapeutic approaches.

Background: Truncating variants in the Titin gene (TTNtvs) are common in individuals with idiopathic dilated cardiomyopathy (DCM). However, a comprehensive genomics-first evaluation of the impact of TTNtvs in different clinical contexts, and the evaluation of modifiers such as genetic ancestry, has not been performed. Methods: We reviewed whole exome sequence data for >71 000 individuals (61 040 from the Geisinger MyCode Community Health Initiative (2007 to present) and 10 273 from the PennMedicine BioBank (2013 to present) to identify anyone with TTNtvs. We further selected individuals with TTNtvs in exons highly expressed in the heart (proportion spliced in [PSI] >0.9). Using linked electronic health records, we evaluated associations of TTNtvs with diagnoses and quantitative echocardiographic measures, including subanalyses for individuals with and without DCM diagnoses. We also reviewed data from the Jackson Heart Study to validate specific analyses for individuals of African ancestry. Results: Identified with a TTNtv in a highly expressed exon (hiPSI) were 1.2% individuals in PennMedicine BioBank and 0.6% at Geisinger. The presence of a hiPSI TTNtv was associated with increased odds of DCM in individuals of European ancestry (odds ratio [95% CI]: 18.7 [9.1–39.4] {PennMedicine BioBank} and 10.8 [7.0–16.0] {Geisinger}). hiPSI TTNtvs were not associated with DCM in individuals of African ancestry, despite a high DCM prevalence (odds ratio, 1.8 [0.2–13.7]; P =0.57). Among 244 individuals of European ancestry with DCM in PennMedicine BioBank, hiPSI TTNtv carriers had lower left ventricular ejection fraction (β=–12%, P =3×10 –7 ), and increased left ventricular diameter (β=0.65 cm, P =9×10 –3 ). In the Geisinger cohort, hiPSI TTNtv carriers without a cardiomyopathy diagnosis had more atrial fibrillation (odds ratio, 2.4 [1.6–3.6]) and heart failure (odds ratio, 3.8 [2.4–6.0]), and lower left ventricular ejection fraction (β=–3.4%, P =1×10 –7 ). Conclusions: Individuals of European ancestry with hiPSI TTNtv have an abnormal cardiac phenotype characterized by lower left ventricular ejection fraction, irrespective of the clinical manifestation of cardiomyopathy. Associations with arrhythmias, including atrial fibrillation, were observed even when controlling for cardiomyopathy diagnosis. In contrast, no association between hiPSI TTNtvs and DCM was discerned among individuals of African ancestry. Given these findings, clinical identification of hiPSI TTNtv carriers may alter clinical management strategies.

Heart failure is a leading cause of mortality, yet our understanding of the genetic interactions underlying this disease remains incomplete. Here, we harvest 1352 healthy and failing human hearts directly from transplant center operating rooms, and obtain genome-wide genotyping and gene expression measurements for a subset of 313. We build failing and non-failing cardiac regulatory gene networks, revealing important regulators and cardiac expression quantitative trait loci (eQTLs). PPP1R3A emerges as a regulator whose network connectivity changes significantly between health and disease. RNA sequencing after PPP1R3A knockdown validates network-based predictions, and highlights metabolic pathway regulation associated with increased cardiomyocyte size and perturbed respiratory metabolism. Mice lacking PPP1R3A are protected against pressure-overload heart failure. We present a global gene interaction map of the human heart failure transition, identify previously unreported cardiac eQTLs, and demonstrate the discovery potential of disease-specific networks through the description of PPP1R3A as a central regulator in heart failure., The genetic and pathogenetic basis of heart failure is incompletely understood. Here, the authors present a high-fidelity tissue collection from rapidly preserved failing and non-failing control hearts which are used for eQTL mapping and network analysis, resulting in the prioritization of PPP1R3A as a heart failure gene.

Since its original description in 1893 by Willem van Einthoven, the electrocardiogram (ECG) has been instrumental in the recognition of a wide array of cardiac disorders1,2. Although many electrocardiographic patterns have been well described, the underlying biology is incompletely understood. Genetic associations of particular features of the ECG have been identified by genome wide studies. This snapshot approach only provides fragmented information of the underlying genetic makeup of the ECG. Here, we follow the effecs of individual genetic variants through the complete cardiac cycle the ECG represents. We found that genetic variants have unique morphological signatures not identfied by previous analyses. By exploiting identified abberations of these morphological signatures, we show that novel genetic loci can be identified for cardiac disorders. Our results demonstrate how an integrated approach to analyse high-dimensional data can further our understanding of the ECG, adding to the earlier undertaken snapshot analyses of individual ECG components. We anticipate that our comprehensive resource will fuelin silicoexplorations of the biological mechanisms underlying cardiac traits and disorders represented on the ECG. For example, known disease causing variants can be used to identify novel morphological ECG signatures, which in turn can be utilized to prioritize genetic variants or genes for functional validation. Furthermore, the ECG plays a major role in the development of drugs, a genetic assessment of the entire ECG can drive such developments.

Identifying genetic markers for heterogeneous complex diseases such as heart failure has been challenging, and may require prohibitively large cohort sizes in genome-wide association studies (GWAS) in order to demonstrate statistical significance1. On the other hand, chromatin quantitative trait loci (QTL), elucidated by direct epigenetic profiling of specific human tissues, may contribute towards prioritising variants for disease-association. Here, we captured non-coding genetic variants by performing enhancer H3K27ac ChIP-seq in 70 human control and end-stage failing hearts, mapping out a comprehensive catalogue of 47,321 putative human heart enhancers. 3,897 differential acetylation peaks (FDR < 0.05) pointed to recognizable pathways altered in heart failure (HF). To identify cardiac histone acetylation QTLs (haQTLs), we regressed out confounding factors including HF disease status, and employed the G-SCI test2 to call out 1,680 haQTLs (FDR < 0.1). A subset of these showed significant association to gene expression, either in cis (180), or through long range interactions (81), identified by Hi-C and Hi-ChIP performed on a subset of hearts. Furthermore, a concordant relationship was found between the gain or disruption of specific transcription factor (TF) binding motifs, inferred from alternative alleles at the haQTLs, associated with altered H3K27ac peak heights. Finally, colocalisation of our haQTLs with heart-related GWAS datasets allowed us to identify 62 unique loci. Disease-association for these new loci may indeed be mediated through modification of H3K27-acetylation enrichment and their corresponding gene expression differences.

Author(s): Spurrell, Cailyn; Barozzi, Iros; Mannion, Brandon; Blow, Matthew; Fukuda-Yuzawa, Yoko; Afzal, Sarah; Akiyama, Jennifer; Afzal, Veena; Tran, Stella; Plajzer-Frick, Ingrid; Novak, Catherine; Kato, Momoe; Lee, Elizabeth; Garvin, Tyler; Pham, Quan; Harrington, Anne; Lisgo, Steven; Bristow, James; Cappola, Thomas; Morley, Michael; Margulies, Kenneth; Pennacchio, Len; Dickel, Diane; Visel, Axel | Abstract: Heart disease is associated with re-expression of key transcription factors normally active only during prenatal development of the heart. However, the impact of this reactivation on the genome-wide regulatory landscape in heart disease has remained obscure. Here we show that pervasive epigenomic changes occur in heart disease, with thousands of regulatory sequences reacquiring fetal-like chromatin signatures. We used RNA-seq and ChIP-seq targeting a histone modification associated with active transcriptional enhancers to generate genome-wide enhancer maps from left ventricle tissue from 18 healthy controls and 18 individuals with idiopathic dilated cardiomyopathy (DCM). Healthy individuals had a highly reproducible epigenomic landscape, consisting of more than 31,000 predicted heart enhancers. In contrast, we observed reproducible disease-associated gains or losses of activity at more than 7,500 predicted heart enhancers. Next, we profiled human fetal heart tissue by ChIP-seq and RNA-seq. Comparison with adult tissues revealed that the heart disease epigenome and transcrip-tome both shift toward a fetal-like state, with 3,400 individual enhancers sharing fetal regulatory properties. Our results demonstrate widespread epigenomic changes in DCM, and we provide a comprehensive data resource ( http://heart.lbl.gov ) for the mechanistic exploration of heart disease etiology.

Background: The effects of thyroid dysfunction in patients with preexisting heart failure have not been adequately studied. We examined the prevalence of thyroid dysfunction and associations with cardiovascular outcomes in a large, prospective cohort of outpatients with preexisting heart failure. Methods and Results: We examined associations between thyroid dysfunction and New York Heart Association class, atrial fibrillation, and a composite end point of ventricular assist device placement, heart transplantation, or death in 1365 participants with heart failure enrolled in the Penn Heart Failure Study. Mean age was 57 years, 35% were women, and the majority had New York Heart Association class II (45%) or III (32%) symptoms. More severe heart failure was associated with higher thyroid-stimulating hormone (TSH), higher free thyroxine (FT4), and lower total triiodothyronine (TT3) concentrations ( P P ≤0.01 all models). There were 462 composite end points over a median 4.2 years of follow-up. In adjusted models, compared with euthyroidism, subclinical hypothyroidism (TSH 4.51–19.99 mIU/L with normal FT4) was associated with an increased risk of the composite end point overall (hazard ratio, 1.82; 95% CI, 1.27–2.61; P =0.001) and in the subgroup with TSH ≥7.00 mIU/L (hazard ratio, 3.25; 95% CI, 1.96–5.39; P P =0.34). Isolated low T3 was also associated with the composite end point (hazard ratio, 2.12; 95% CI, 1.65–2.72; P Conclusions: In patients with preexisting heart failure, subclinical hypothyroidism with TSH ≥7 mIU/L and isolated low T3 levels are associated with poor prognosis. Clinical trials are needed to explore therapeutic effects of T4 and T3 administration in heart failure.

Pathogenic mutations in LAMIN A/C (LMNA) cause abnormal nuclear structure and laminopathies. These diseases have myriad tissue-specific phenotypes, including dilated cardiomyopathy (DCM), but how LMNA mutations result in tissue-restricted disease phenotypes remains unclear. We introduced LMNA mutations from individuals with DCM into human induced pluripotent stem cells (hiPSCs) and found that hiPSC-derived cardiomyocytes, in contrast to hepatocytes or adipocytes, exhibit aberrant nuclear morphology and specific disruptions in peripheral chromatin. Disrupted regions were enriched for transcriptionally active genes and regions with lower LAMIN B1 contact frequency. The lamina-chromatin interactions disrupted in mutant cardiomyocytes were enriched for genes associated with non-myocyte lineages and correlated with higher expression of those genes. Myocardium from individuals with LMNA variants similarly showed aberrant expression of non-myocyte pathways. We propose that the lamina network safeguards cellular identity and that pathogenic LMNA variants disrupt peripheral chromatin with specific epigenetic and molecular characteristics, causing misexpression of genes normally expressed in other cell types.

Background Heart failure (HF) guidelines recommend brain natriuretic peptide (BNP) and multivariable risk scores, such as the Seattle Heart Failure Model (SHFM), to predict risk in HF with reduced ejection fraction (HFrEF). A practical way to integrate information from these 2 prognostic tools is lacking. We sought to establish a SHFM+BNP risk-stratification algorithm. Methods The retrospective derivation cohort included consecutive patients with HFrEF at the Mayo Clinic. One-year outcome (death, transplantation or ventricular assist device) was assessed. The SHFM+BNP algorithm was derived by stratifying patients within SHFM-predicted risk categories (≤2.5%, 2.6% to ≤10%, >10%) according to BNP above or below 700 pg/ml and comparing SHFM-predicted and observed event rates within each SHFM+BNP category. The algorithm was validated in a prospective, multicenter HFrEF registry (Penn HF Study). Results Derivation ( n = 441; 1-year event rate 17%) and validation ( n = 1,513; 1-year event rate 12%) cohorts differed with the former being older and more likely ischemic with worse symptoms, lower EF, worse renal function and higher BNP and SHFM scores. In both cohorts, across the 3 SHFM-predicted risk strata, a BNP >700 pg/ml consistently identified patients with approximately 3-fold the risk that the SHFM would have otherwise estimated, regardless of stage of HF, intensity and duration of HF therapy and comorbidities. Conversely, the SHFM was appropriately calibrated in patients with a BNP Conclusion The simple SHFM+BNP algorithm displays stable performance across diverse HFrEF cohorts and may enhance risk stratification to enable appropriate decision-making regarding HF therapeutic or palliative strategies.

Clinical studies have suggested the prognostic value of galectin-3, a marker of fibrosis, in chronic heart failure. However, the specific role of galectin-3, compared with established biomarkers, remains uncertain.The Penn Heart Failure Study was an ambulatory heart failure cohort that included 1385 participants with reduced (1141), preserved (106), and recovered (138) left ventricular ejection fraction (LVEF). Cox regression models determined the association between galectin-3 and risk of all-cause mortality, cardiac transplantation, or placement of a ventricular assist device. Receiver operating characteristic curves compared the prognostic accuracy of galectin-3, high-sensitivity soluble Toll-like receptor 2 (ST2), troponin I, and B-type natriuretic peptide (BNP) at 1 and 5 years. Higher galectin-3 levels were associated with an increased risk of adverse events (adjusted hazard ratio of 1.96 for each doubling in galectin-3; P .001). This association was most pronounced among participants with preserved LVEF (adjusted hazard ratio 3.30; P .001). At 5 years, galectin-3 was the most accurate discriminator of risk among participants with preserved LVEF (area under the curve 0.782; P = .81 vs high-sensitivity ST2; P = .029 vs troponin I; P = .35 vs BNP). BNP was most accurate among participants with reduced and recovered LVEF (areas under the curves 0.716 and 0.728, respectively).Galectin-3 could have prognostic value for long-term events among patients with heart failure and preserved ejection fraction.

We conducted a meta-analysis of pharmacogenomic substudies of three randomized trials conducted in patients with decompensated heart failure (HF) that were led by National Heart Lung and Blood Institute (NHLBI)-funded HF Network to test the hypothesis that candidate genes modulate net fluid loss and weight change in patients with decompensated HF treated with a furosemide-based diuretic regimen. Although none of the genetic variants previously shown to modulate the effects of loop diuretics in healthy individuals were associated with net fluid loss after 72 h of treatment, a set of rare variants in the APOL1 gene, which codes for apolipoprotein L1 (P=0.0005 in the random effects model), was associated with this end point. Moreover, a common variant in the multidrug resistance protein-4 coding gene (ABCC4, rs17268282) was associated with weight loss with furosemide use (P=0.0001). Our results suggest that both common and rare genetic variants modulate the response to a furosemide-based diuretic regimen in patients with decompensated HF.

Background The genetic determinants of heart failure (HF) and response to medical therapy remain unknown. We hypothesized that identifying genetic variants of HF that associate with response to medical therapy would elucidate the genetic basis of cardiac function. Objectives This study sought to identify genetic variations associated with response to HF therapy. Methods This study compared extremes of response to medical therapy in 866 HF patients using a genome-wide approach that informed the systems-based design of a customized single nucleotide variant array. The effect of genotype on gene expression was measured using allele-specific luciferase reporter assays. Candidate gene transcription-deficient mice underwent echocardiography and treadmill exercise. The ability of the target gene agonist to rescue mice from chemically-induced HF was assessed with echocardiography. Results Of 866 HF patients, 136 had an ejection fraction improvement of 20% attributed to resynchronization (n = 83), revascularization (n = 7), tachycardia resolution (n = 2), alcohol cessation (n = 1), or medications (n = 43). Those with the minor allele for rs7767652, upstream of hypocretin (orexin) receptor-2 (HCRTR2), were less likely to have improved left ventricular function (odds ratio: 0.40 per minor allele; p = 3.29 × 10−5). In a replication cohort of 798 patients, those with a minor allele for rs7767652 had a lower prevalence of ejection fraction >35% (odds ratio: 0.769 per minor allele; p = 0.021). In an HF model, HCRTR2-deficient mice exhibited poorer cardiac function, worse treadmill exercise capacity, and greater myocardial scarring. Orexin, an HCRTR2 agonist, rescued function in this HF mouse model. Conclusions A systems approach identified a novel genetic contribution to human HF and a promising therapeutic agent efficacious in an HF model.

Background: Coronary artery disease (CAD) is influenced by genetic variation and traditional risk factors. Polygenic risk scores (PRS), which can be ascertained before the development of traditional risk factors, have been shown to identify individuals at elevated risk of CAD. Here, we demonstrate that a genome-wide PRS for CAD predicts all-cause mortality after accounting for not only traditional cardiovascular risk factors but also angiographic CAD itself. Methods: Individuals who underwent coronary angiography and were enrolled in an institutional biobank were included; those with prior myocardial infarction or heart transplant were excluded. Using a pruning-and-thresholding approach, a genome-wide PRS comprised of 139 239 variants was calculated for 1503 participants who underwent coronary angiography and genotyping. Individuals were categorized into high PRS (hiPRS) and low-PRS control groups using the maximally selected rank statistic. Stratified analysis based on angiographic findings was also performed. The primary outcome was all-cause mortality following the index coronary angiogram. Results: Individuals with hiPRS were younger than controls (66 years versus 69 years; P =2.1×10 -5 ) but did not differ by sex, body mass index, or traditional risk-factor profiles. Individuals with hiPRS were at significantly increased risk of all-cause mortality after cardiac catheterization, adjusting for traditional risk factors and angiographic extent of CAD (hazard ratio, 1.6; 95% CI, 1.2–2.2; P =0.004). The strongest increase in risk of all-cause mortality conferred by hiPRS was seen among individuals without angiographic CAD (hazard ratio, 2.4; 95% CI, 1.1–5.5; P =0.04). In the overall cohort, adding hiPRS to traditional risk assessment improved prediction of 5-year all-cause mortality (area under the receiver-operating curve 0.70; 95% CI, 0.66–0.75 versus 0.66; 95% CI, 0.61–0.70; P =0.001). Conclusions: A genome-wide PRS improves risk stratification when added to traditional risk factors and coronary angiography. Individuals without angiographic CAD but with hiPRS remain at significantly elevated risk of mortality.

Background: Genetic variants at the SCN5A / SCN10A locus are strongly associated with electrocardiographic PR and QRS intervals. While SCN5A is the canonical cardiac sodium channel gene, the role of SCN10A in cardiac conduction is less well characterized. Methods: We sequenced the SCN10A locus in 3699 European-ancestry individuals to identify variants associated with cardiac conduction, and replicated our findings in 21,000 individuals of European ancestry. We examined association with expression in human atrial tissue. We explored the biophysical effect of variation on channel function using cellular electrophysiology. Results: We identified 2 intronic single nucleotide polymorphisms in high linkage disequilibrium ( r 2 =0.86) with each other to be the strongest signals for PR (rs10428132, β=−4.74, P =1.52×10 −14 ) and QRS intervals (rs6599251, QRS β=−0.73; P =1.2×10 −4 ), respectively. Although these variants were not associated with SCN5A or SCN10A expression in human atrial tissue (n=490), they were in high linkage disequilibrium ( r 2 ≥0.72) with a common SCN10A missense variant, rs6795970 (V1073A). In total, we identified 7 missense variants, 4 of which (I962V, P1045T, V1073A, and L1092P) were associated with cardiac conduction. These 4 missense variants cluster in the cytoplasmic linker of the second and third domains of the SCN10A protein and together form 6 common haplotypes. Using cellular electrophysiology, we found that haplotypes associated with shorter PR intervals had a significantly larger percentage of late current compared with wild-type (I962V+V1073A+L1092P, 20.2±3.3%, P =0.03, and I962V+V1073A, 22.4±0.8%, P =0.0004 versus wild-type 11.7±1.6%), and the haplotype associated with the longest PR interval had a significantly smaller late current percentage (P1045T, 6.4±1.2%, P =0.03). Conclusions: Our findings suggest an association between genetic variation in SCN10A , the late sodium current, and alterations in cardiac conduction.

Background ECG global electrical heterogeneity ( GEH ) is associated with sudden cardiac death. We hypothesized that a genome‐wide association study would identify genetic loci related to GEH . Methods and Results We tested genotyped and imputed variants in black (N=3057) and white (N=10 769) participants in the ARIC (Atherosclerosis Risk in Communities) study and CHS (Cardiovascular Health Study). GEH ( QRS ‐T angle, sum absolute QRST integral, spatial ventricular gradient magnitude, elevation, azimuth) was measured on 12‐lead ECG s. Linear regression models were constructed with each GEH variable as an outcome, adjusted for age, sex, height, body mass index, study site, and principal components to account for ancestry. GWAS identified 10 loci that showed genome‐wide significant association with GEH in whites or joint ancestry. The strongest signal (rs7301677, near TBX 3 ) was associated with QRS ‐T angle (white standardized β+0.16 [95% CI 0.13–0.19]; P =1.5×10 −26 ), spatial ventricular gradient elevation (+0.11 [0.08–0.14]; P =2.1×10 −12 ), and spatial ventricular gradient magnitude (−0.12 [95% CI −0.15 to −0.09]; P =5.9×10 −15 ). Altogether, GEH ‐ SNP s explained 1.1% to 1.6% of GEH variance. Loci on chromosomes 4 (near HMCN 2 ), 5 ( IGF 1R ), 11 (11p11.2 region cluster), and 7 (near ACTB ) are novel ECG phenotype‐associated loci. Several loci significantly associated with gene expression in the left ventricle ( HMCN 2 locus—with HMCN 2 ; IGF 1R locus—with IGF 1R ), and atria ( RP 11‐481J2.2 locus—with expression of a long non‐coding RNA and NDRG 4 ). Conclusions We identified 10 genetic loci associated with ECG GEH . Replication of GEH GWAS findings in independent cohorts is warranted. Further studies of GEH ‐loci may uncover mechanisms of arrhythmogenic remodeling in response to cardiovascular risk factors.

Background: Inhibition of PKC-α (protein kinase C-α) enhances contractility and cardioprotection in animal models, but effects in humans are unknown. Genotypes at rs9912468 strongly associate with PRKCA expression in the left ventricle, enabling genetic approaches to measure effects of reduced PKC-α in human populations. Methods and Results: We analyzed the cis expression quantitative trait locus for PRKCA marked by rs9912468 using 313 left ventricular specimens from European Ancestry patients. The forward strand minor allele (G) at rs9912468 is associated with reduced PKC-α transcript abundance (1.7-fold reduction in minor allele homozygotes, P =1×10 −41 ). This association was cardiac specific in expression quantitative trait locus data sets that span 16 human tissues. Cardiac epigenomic data revealed a predicted enhancer in complete ( R 2 =1.0) linkage disequilibrium with rs9912468 within intron 2 of PRKCA. We cloned this region and used reporter constructs to verify cardiac-specific enhancer activity in vitro in cardiac and noncardiac cells and in vivo in zebrafish. The PRKCA enhancer contains 2 common genetic variants and 4 haplotypes; the haplotype correlated with the rs9912468 PKC-α–lowering allele (G) showed lowest activity. In contrast to previous reports in animal models, the PKC-α–lowering allele is associated with adverse left ventricular remodeling (higher mass, larger diastolic dimension), reduced fractional shortening, and higher risk of dilated cardiomyopathy in human populations. Conclusions: These findings support PKC-α as a regulator of the human heart but suggest that PKC-α inhibition may adversely affect the left ventricle depending on timing and duration. Pharmacological studies in human subjects are required to discern potential benefits and harms of PKC-α inhibitors as an approach to treat heart disease.

Atrial fibrillation (AF) affects more than 33 million individuals worldwide 1 and has a complex heritability 2 . We conducted the largest meta-analysis of genome-wide association studies (GWAS) for AF to date, consisting of more than half a million individuals, including 65,446 with AF. In total, we identified 97 loci significantly associated with AF, including 67 that were novel in a combined-ancestry analysis, and 3 that were novel in a European-specific analysis. We sought to identify AF-associated genes at the GWAS loci by performing RNA-sequencing and expression quantitative trait locus analyses in 101 left atrial samples, the most relevant tissue for AF. We also performed transcriptome-wide analyses that identified 57 AF-associated genes, 42 of which overlap with GWAS loci. The identified loci implicate genes enriched within cardiac developmental, electrophysiological, contractile and structural pathways. These results extend our understanding of the biological pathways underlying AF and may facilitate the development of therapeutics for AF.

Background— Oxidative stress may contribute to heart failure (HF) progression. Inhibiting xanthine oxidase in hyperuricemic HF patients may improve outcomes. Methods and Results— We randomly assigned 253 patients with symptomatic HF, left ventricular ejection fraction ≤40%, and serum uric acid levels ≥9.5 mg/dL to receive allopurinol (target dose, 600 mg daily) or placebo in a double-blind, multicenter trial. The primary composite end point at 24 weeks was based on survival, worsening HF, and patient global assessment. Secondary end points included change in quality of life, submaximal exercise capacity, and left ventricular ejection fraction. Uric acid levels were significantly reduced with allopurinol in comparison with placebo (treatment difference, –4.2 [–4.9, –3.5] mg/dL and –3.5 [–4.2, –2.7] mg/dL at 12 and 24 weeks, respectively, both P P =0.68). At 12 and 24 weeks, there was no significant difference in change in Kansas City Cardiomyopathy Questionnaire scores or 6-minute walk distances between the 2 groups. At 24 weeks, left ventricular ejection fraction did not change in either group or between groups. Rash occurred more frequently with allopurinol (10% versus 2%, P =0.01), but there was no difference in serious adverse event rates between the groups (20% versus 15%, P =0.36). Conclusions— In high-risk HF patients with reduced ejection fraction and elevated uric acid levels, xanthine oxidase inhibition with allopurinol failed to improve clinical status, exercise capacity, quality of life, or left ventricular ejection fraction at 24 weeks. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00987415.

Background— The aim of this study is to examine the relationship between time in the therapeutic range (TTR) and clinical outcomes in heart failure patients in sinus rhythm treated with warfarin. Methods and Results— We used data from the Warfarin versus Aspirin in Reduced Cardiac Ejection Fraction (WARCEF) trial to assess the relationship of TTR with the WARCEF primary outcome (ischemic stroke, intracerebral hemorrhage, or death), with death alone, ischemic stroke alone, major hemorrhage alone, and net clinical benefit (primary outcome and major hemorrhage combined). Multivariable Cox models were used to examine how the event risk changed with TTR and to compare the high TTR, low TTR, and aspirin-treated patients, with TTR being treated as a time-dependent covariate. A total of 2217 patients were included in the analyses; among whom 1067 were randomized to warfarin and 1150 were randomized to aspirin. The median (interquartile range) follow-up duration was 3.6 (2.0–5.0) years. Mean (±SD) age was 61±11.3 years, with 80% being men. The mean (±SD) TTR was 57% (±28.5%). Increasing TTR was significantly associated with reduction in primary outcome (adjusted P P =0.001), and improved net clinical benefit (adjusted P P =0.082 for ischemic stroke and adjusted P =0.109 for major hemorrhage). Conclusions— In patients with heart failure in sinus rhythm, increasing TTR is associated with better outcome and improved net clinical benefit. Patients in whom good quality anticoagulation can be achieved may benefit from the use of anticoagulants. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00041938.

Heart failure is a complex clinical syndrome and has become the most common reason for adult hospitalization in developed countries. Two subtypes of heart failure, ischemic heart disease (ISCH) and dilated cardiomyopathy (DCM), have been studied using microarray platforms. However, microarray has limited resolution. Here we applied RNA sequencing (RNA-Seq) to identify gene signatures for heart failure from six individuals, including three controls, one ISCH and two DCM patients. Using genes identified from this small RNA-Seq dataset, we were able to accurately classify heart failure status in a much larger set of 313 individuals. The identified genes significantly overlapped with genes identified via genome-wide association studies for cardiometabolic traits and the promoters of those genes were enriched for binding sites for transcriptions factors. Our results indicate that it is possible to use RNA-Seq to classify disease status for complex diseases such as heart failure using an extremely small training dataset.

Background— Inorganic nitrate (NO 3 − ), abundant in certain vegetables, is converted to nitrite by bacteria in the oral cavity. Nitrite can be converted to nitric oxide in the setting of hypoxia. We tested the hypothesis that NO 3 − supplementation improves exercise capacity in heart failure with preserved ejection fraction via specific adaptations to exercise. Methods and Results— Seventeen subjects participated in this randomized, double-blind, crossover study comparing a single dose of NO 3 -rich beetroot juice (NO 3 − , 12.9 mmol) with an identical nitrate-depleted placebo. Subjects performed supine-cycle maximal-effort cardiopulmonary exercise tests, with measurements of cardiac output and skeletal muscle oxygenation. We also assessed skeletal muscle oxidative function. Study end points included exercise efficiency (total work/total oxygen consumed), peak o 2 , total work performed, vasodilatory reserve, forearm mitochondrial oxidative function, and augmentation index (a marker of arterial wave reflections, measured via radial arterial tonometry). Supplementation increased plasma nitric oxide metabolites (median, 326 versus 10 μmol/L; P =0.0003), peak o 2 (12.6±3.7 versus 11.6±3.1 mL O 2 ·min −1 ·kg −1 ; P =0.005), and total work performed (55.6±35.3 versus 49.2±28.9 kJ; P =0.04). However, efficiency was unchanged. NO 3 − led to greater reductions in systemic vascular resistance (−42.4±16.6% versus −31.8±20.3%; P =0.03) and increases in cardiac output (121.2±59.9% versus 88.7±53.3%; P =0.006) with exercise. NO 3 − reduced aortic augmentation index (132.2±16.7% versus 141.4±21.9%; P =0.03) and tended to improve mitochondrial oxidative function. Conclusions— NO 3 − increased exercise capacity in heart failure with preserved ejection fraction by targeting peripheral abnormalities. Efficiency did not change as a result of parallel increases in total work and o 2. NO 3 − increased exercise vasodilatory and cardiac output reserves. NO 3 − also reduced arterial wave reflections, which are linked to left ventricular diastolic dysfunction and remodeling. Clinical Trial Registration— URL: www.clinicaltrials.gov . Unique identifier: NCT01919177.

Renal dysfunction (RD) is associated with increased mortality in heart failure (HF). The aim of this study was to identify whether worsened or improved renal function during mid-term follow-up is associated with worsened outcomes in patients with chronic HF. A total of 892 participants from a multicenter cohort study of chronic HF were followed over 3.1 ± 1.9 years of enrollment. Worsened and improved renal functions were tested with multivariate models as independent predictors of HF hospitalization and mortality. Although 12% of subjects experienced a ≥25% decrease in estimated glomerular filtration rate (eGFR), 17% experienced a ≥25% increase in eGFR, and there was stability of kidney function observed in the cohort as a whole. The quartile with the worst RD at any point in time had increased risk of HF hospitalization and mortality. Worsened eGFR was associated with HF outcomes in the unadjusted (hazard ratio = 1.71, 95% confidence interval 1.04 to 2.81, p = 0.035), but not the adjusted analysis. Improvement in eGFR was not associated with outcome (p = 0.453). In chronic HF, the severity of RD predicts risk of poor outcome better than changes in renal function during mid-term follow-up. This suggests that in patients with appropriately treated chronic HF, worsening renal function in itself does not yield useful prognostic information and may not reflect poor outcome.

Objectives: This study sought to evaluate if diastolic pulmonary gradient (DPG) can predict survival in patients with pulmonary hypertension due to left heart disease (PH-LHD).Background: P...

Hypertrophic cardiomyopathy, defined as unexplained left ventricular hypertrophy, has an estimated prevalence of at least 1 in 500 and is among the most common forms of inherited heart disease.1 The pathophysiology of hypertrophic cardiomyopathy is complex and involves the interplay between diastolic dysfunction, myocardial ischemia, systolic anterior motion of the mitral valve resulting in outflow tract obstruction, and arrhythmia.2 Clinical presentations are heterogeneous and range from asymptomatic to palpitations, dyspnea, exercise intolerance, chest pain, syncope, and sudden death. Although the absolute risk of cardiac mortality is less than 1% per year,3 hypertrophic cardiomyopathy remains a common cause of sudden cardiac death in the young, especially in competitive athletes.4,5 Since hypertrophic cardiomyopathy has autosomal dominant inheritance, relatives of affected individuals have substantial risk of disease. Clinical evaluation of family members and cascade screening with genetic testing can identify those affected, many of whom are asymptomatic. When properly treated, the majority of patients with hypertrophic cardiomyopathy will have a normal life span.3

Background Identification of heart failure (HF) patients at risk for hospitalization may improve care and reduce costs. We evaluated 9 biomarkers as predictors of cardiac hospitalization in chronic HF. Methods and Results In a multicenter cohort of 1,512 chronic HF outpatients, we assessed the association between 9 biomarkers and cardiac hospitalization with the use of a recurrent events approach. Over a median follow-up of 4 years, 843 participants experienced ≥1 hospitalizations (total 2,178 hospitalizations). B-type natriuretic peptide (BNP) and troponin I (TnI) exhibited the strongest associations with risk of hospitalization (hazard ratio [HR] 3.8 [95% confidence interval (CI) 2.9-4.9] and HR 3.3 [95% CI 2.8-3.9]; 3rd vs 1st tertiles). Soluble Fms-like tyrosine kinase receptor 1 (sFlt-1) exhibited the next strongest association (HR 2.8 [95% CI 2.4–3.4]), followed by soluble Toll-like receptor 2 (HR 2.3 [95% CI 2.0–2.8]) and creatinine (HR 1.9 [95% CI 1.6–2.4]). Within ischemic/nonischemic subgroups, BNP and TnI remained most strongly associated. Except for creatinine, HRs for all biomarkers studied were smaller within the ischemic subgroup, suggesting greater importance of cardiorenal interactions in decompensation of ischemic HF. Conclusion Although BNP and TnI exhibited the strongest associations with hospitalization, etiology-dependent associations for the remaining biomarkers suggest etiology-specific mechanisms for HF exacerbation. sFlt-1 exhibited a strong association with cardiac hospitalization, highlighting its potential role as a biomarker of HF morbidity.

The QT interval, an electrocardiographic measure reflecting myocardial repolarization, is a heritable trait. QT prolongation is a risk factor for ventricular arrhythmias and sudden cardiac death (SCD) and could indicate the presence of the potentially lethal mendelian long-QT syndrome (LQTS). Using a genome-wide association and replication study in up to 100,000 individuals, we identified 35 common variant loci associated with QT interval that collectively explain similar to 8-10% of QT-interval variation and highlight the importance of calcium regulation in myocardial repolarization. Rare variant analysis of 6 new QT interval-associated loci in 298 unrelated probands with LQTS identified coding variants not found in controls but of uncertain causality and therefore requiring validation. Several newly identified loci encode proteins that physically interact with other recognized repolarization proteins. Our integration of common variant association, expression and orthogonal protein-protein interaction screens provides new insights into cardiac electrophysiology and identifies new candidate genes for ventricular arrhythmias, LQTS and SCD.

Monte-Carlo (MC) Logic and Logic Feature Selection (logicFS) identify binary predictors of outcome using repeated iterations of logic regression, a variable selection method that identifies Boolean combinations of predictors. Both methods compute the frequency with which predictors appear in the model with the output of the logicFS program providing specific summaries of predictor form. We sought to identify variables related to transcription factor-related regulation of gene expression differences in a study of failing and non-failing hearts. Results based broadly on the frequency of occurrence of predictors into the MC Logic or logicFS models were similar. However key to logicFS are variable importance measures (VIMs), which augment the frequency metrics and seek to evaluate a predictor's contribution to classification. Analytic work and simulation studies indicate that the VIM vary as a function of the joint prevalence of outcome and predictor. Thus, findings from logicFS have limited generalizability,...

Motivation: The declining cost of generating DNA sequence is promoting an increase in whole genome sequencing, especially as applied to the human genome. Whole genome analysis requires the alignment and comparison of raw sequence data, and results in a computational bottleneck because of limited ability to analyze multiple genomes simultaneously. Results: We now adapted a Cray XE6 supercomputer to achieve the parallelization required for concurrent multiple genome analysis. This approach not only markedly speeds computational time but also results in increased usable sequence per genome. Relying on publically available software, the Cray XE6 has the capacity to align and call variants on 240 whole genomes in ∼50 h. Multisample variant calling is also accelerated. Availability and implementation: The MegaSeq workflow is designed to harness the size and memory of the Cray XE6, housed at Argonne National Laboratory, for whole genome analysis in a platform designed to better match current and emerging sequencing volume. Contact: emcnally@uchicago.edu

Background The human left and right atria have different susceptibilities to develop atrial fibrillation (AF). However, the molecular events related to structural and functional changes that enhance AF susceptibility are still poorly understood. Objective The purpose of this study was to characterize gene expression and genetic variation in human atria. Methods We studied the gene expression profiles and genetic variations in 53 left atrial and 52 right atrial tissue samples collected from the Myocardial Applied Genomics Network (MAGNet) repository. The tissues were collected from heart failure patients undergoing transplantation and from unused organ donor hearts with normal ventricular function. Gene expression was profiled using the Affymetrix GeneChip Human Genome U133A Array. Genetic variation was profiled using the Affymetrix Genome-Wide Human SNP Array 6.0. Results We found that 109 genes were differentially expressed between left and right atrial tissues. A total of 187 and 259 significant cis-associations between transcript levels and genetic variants were identified in left and right atrial tissues, respectively. We also found that a single nucleotide polymorphism at a known AF locus, rs3740293, was associated with the expression of MYOZ1 in both left and right atrial tissues. Conclusion We found a distinct transcriptional profile between the right and left atrium and extensive cis-associations between atrial transcripts and common genetic variants. Our results implicate MYOZ1 as the causative gene at the chromosome 10q22 locus for AF.

Heart failure (HF) is driven by the interplay between master regulatory transcription factors and dynamic alterations in chromatin structure. While pathologic gene transactivation in this context is known to be associated with recruitment of histone acetyl-transferases and local chromatin hyperacetylation, the role of epigenetic reader proteins in cardiac biology is unknown. We therefore undertook a first study of acetyl-lysine reader proteins, or bromodomains, in HF. Using a chemical genetic approach, we establish a central role for BET-family bromodomain proteins in gene control during HF pathogenesis. BET inhibition potently suppresses cardiomyocyte hypertrophy in vitro and pathologic cardiac remodeling in vivo. Integrative transcriptional and epigenomic analyses reveal that BET proteins function mechanistically as pause-release factors critical to activation of canonical master regulators and effectors that are central to HF pathogenesis and relevant to the pathobiology of failing human hearts. This study implicates epigenetic readers in cardiac biology and identifies BET co-activator proteins as therapeutic targets in HF.

Genetic variants at theWe sequenced theWe identified 2 intronic single nucleotide polymorphisms in high linkage disequilibrium (Our findings suggest an association between genetic variation in

Background and objectives Heart failure is the most frequent cardiac complication of CKD. Left ventricular hypertrophy is common and develops early in CKD, but studies have not adequately evaluated the association of left ventricular mass index with heart failure incidence among men and women with CKD. Design, setting, participants, & measurements We evaluated echocardiograms of 2567 participants without self–reported heart failure enrolled in the Chronic Renal Insufficiency Cohort Study. Two-dimensional echocardiograms were performed at the year 1 study visit and interpreted at a central core laboratory. Left ventricular mass index was calculated using the linear method, indexed to height 2.7 , and analyzed using sex-specific quartiles. The primary outcomes of incident heart failure and all-cause mortality were adjudicated over a median of 6.6 (interquartile range, 5.7–7.6) years. Results Among 2567 participants, 45% were women, and 54% were nonwhite race; mean (SD) age was 59±11 years old, and mean eGFR was 44±17 ml/min per 1.73 m 2 . During a median follow-up period of 6.6 years, 262 participants developed heart failure, and 470 participants died. Compared with participants in the first quartile of left ventricular mass index, those in the highest quartile had higher rates of incident heart failure (hazard ratio, 3.96; 95% confidence interval, 1.96 to 8.02) and mortality (hazard ratio, 1.86; 95% confidence interval, 1.22 to 2.85), even after adjustment for B–type natriuretic peptide, troponin T, mineral metabolism markers, and other cardiovascular disease risk factors. Those in the lowest quartile of ejection fraction had higher rates of incident heart failure (hazard ratio, 3.01; 95% confidence interval, 1.94 to 4.67) but similar mortality rates (hazard ratio, 1.18; 95% confidence interval, 0.89 to 1.57) compared with those in the highest quartile. Diastolic dysfunction was not significantly associated with heart failure or death. Conclusions Among persons with CKD and without history of cardiovascular disease, left ventricular mass index is strongly associated with incident heart failure, even after adjustment for major cardiovascular risk factors and biomarkers.

Background Stable plasma nitric oxide ( NO ) metabolites ( NO M ), composed predominantly of nitrate and nitrite, are attractive biomarkers of NO bioavailability. NO M levels integrate the influence of NO ‐synthase‐derived NO production/metabolism, dietary intake of inorganic nitrate/nitrite, and clearance of NO M . Furthermore, nitrate and nitrite, the most abundant NO M , can be reduced to NO via the nitrate‐nitrite‐ NO pathway. Methods and Results We compared serum NO M among subjects without heart failure (n=126), subjects with heart failure and preserved ejection fraction ( HF p EF ; n=43), and subjects with heart failure and reduced ejection fraction ( HF r EF ; n=32). LV mass and extracellular volume fraction were measured with cardiac MRI . Plasma NO M levels were measured after reduction to NO via reaction with vanadium ( III )/hydrochloric acid. Subjects with HF p EF demonstrated significantly lower unadjusted levels of NO M (8.0 μmol/L; 95% CI 6.2–10.4 μmol/L; ANOVA P =0.013) than subjects without HF (12.0 μmol/L; 95% CI 10.4–13.9 μmol/L) or those with HF r EF (13.5 μmol/L; 95% CI 9.7–18.9 μmol/L). There were no significant differences in NO M between subjects with HF r EF and subjects without HF . In a multivariable model that adjusted for age, sex, race, diabetes mellitus, body mass index, current smoking, systolic blood pressure, and glomerular filtration rate, HF p EF remained a predictor of lower NO M (β=−0.43; P =0.013). NO M did not correlate with LV mass, or LV diffuse fibrosis. Conclusions HF p EF , but not HF r EF , is associated with reduced plasma NO M , suggesting greater endothelial dysfunction, enhanced clearance, or deficient dietary ingestion of inorganic nitrate. Our findings may underlie the salutary effects of inorganic nitrate supplementation demonstrated in recent clinical trials in HF p EF .

Rationale: Nitrate-rich beetroot juice has been shown to improve exercise capacity in heart failure with preserved ejection fraction, but studies using pharmacological preparations of inorganic nitrate are lacking. Objectives: To determine (1) the dose–response effect of potassium nitrate (KNO 3 ) on exercise capacity; (2) the population-specific pharmacokinetic and safety profile of KNO 3 in heart failure with preserved ejection fraction. Methods and Results: We randomized 12 subjects with heart failure with preserved ejection fraction to oral KNO 3 (n=9) or potassium chloride (n=3). Subjects received 6 mmol twice daily during week 1, followed by 6 mmol thrice daily during week 2. Supine cycle ergometry was performed at baseline (visit 1) and after each week (visits 2 and 3). Quality of life was assessed with the Kansas City Cardiomyopathy Questionnaire. The primary efficacy outcome, peak O 2 -uptake, did not significantly improve ( P =0.13). Exploratory outcomes included exercise duration and quality of life. Exercise duration increased significantly with KNO 3 (visit 1: 9.87, 95% confidence interval [CI] 9.31–10.43 minutes; visit 2: 10.73, 95% CI 10.13–11.33 minute; visit 3: 11.61, 95% CI 11.05–12.17 minutes; P =0.002). Improvements in the Kansas City Cardiomyopathy Questionnaire total symptom (visit 1: 58.0, 95% CI 52.5–63.5; visit 2: 66.8, 95% CI 61.3–72.3; visit 3: 70.8, 95% CI 65.3–76.3; P =0.016) and functional status scores (visit 1: 62.2, 95% CI 58.5–66.0; visit 2: 68.6, 95% CI 64.9–72.3; visit 3: 71.1, 95% CI 67.3–74.8; P =0.01) were seen after KNO 3 . Pronounced elevations in trough levels of nitric oxide metabolites occurred with KNO 3 (visit 2: 199.5, 95% CI 98.7–300.2 μmol/L; visit 3: 471.8, 95% CI 377.8–565.8 μmol/L) versus baseline (visit 1: 38.0, 95% CI 0.00–132.0 μmol/L; P 3 did not lead to clinically significant hypotension or methemoglobinemia. After 6 mmol of KNO 3 , systolic blood pressure was reduced by a maximum of 17.9 (95% CI −28.3 to −7.6) mm Hg 3.75 hours later. Peak nitric oxide metabolites concentrations were 259.3 (95% CI 176.2–342.4) μmol/L 3.5 hours after ingestion, and the median half-life was 73.0 (interquartile range 33.4–232.0) minutes. Conclusions: KNO 3 is potentially well tolerated and improves exercise duration and quality of life in heart failure with preserved ejection fraction. This study reinforces the efficacy of KNO 3 and suggests that larger randomized trials are warranted. Clinical Trial Registration : URL: http://www.clinicaltrials.gov . Unique identifier: NCT02256345

Importance Abnormal cardiac metabolism contributes to the pathophysiology of advanced heart failure with reduced left ventricular ejection fraction (LVEF). Glucagon-like peptide 1 (GLP-1) agonists have shown cardioprotective effects in early clinical studies of patients with advanced heart failure, irrespective of type 2 diabetes status. Objective To test whether therapy with a GLP-1 agonist improves clinical stability following hospitalization for acute heart failure. Design, Setting, and Participants Phase 2, double-blind, placebo-controlled randomized clinical trial of patients with established heart failure and reduced LVEF who were recently hospitalized. Patients were enrolled between August 2013 and March 2015 at 24 US sites. Interventions The GLP-1 agonist liraglutide (n = 154) or placebo (n = 146) via a daily subcutaneous injection; study drug was advanced to a dosage of 1.8 mg/d during the first 30 days as tolerated and continued for 180 days. Main Outcomes and Measures The primary end point was a global rank score in which all patients, regardless of treatment assignment, were ranked across 3 hierarchical tiers: time to death, time to rehospitalization for heart failure, and time-averaged proportional change in N-terminal pro-B-type natriuretic peptide level from baseline to 180 days. Higher values indicate better health (stability). Exploratory secondary outcomes included primary end point components, cardiac structure and function, 6-minute walk distance, quality of life, and combined events. Results Among the 300 patients who were randomized (median age, 61 years [interquartile range {IQR}, 52-68 years]; 64 [21%] women; 178 [59%] with type 2 diabetes; median LVEF of 25% [IQR, 19%-33%]; median N-terminal pro-B-type natriuretic peptide level of 2049 pg/mL [IQR, 1054-4235 pg/mL]), 271 completed the study. Compared with placebo, liraglutide had no significant effect on the primary end point (mean rank of 146 for the liraglutide group vs 156 for the placebo group, P = .31). There were no significant between-group differences in the number of deaths (19 [12%] in the liraglutide group vs 16 [11%] in the placebo group; hazard ratio, 1.10 [95% CI, 0.57-2.14]; P = .78) or rehospitalizations for heart failure (63 [41%] vs 50 [34%], respectively; hazard ratio, 1.30 [95% CI, 0.89-1.88]; P = .17) or for the exploratory secondary end points. Prespecified subgroup analyses in patients with diabetes did not reveal any significant between-group differences. The number of investigator-reported hyperglycemic events was 16 (10%) in the liraglutide group vs 27 (18%) in the placebo group and hypoglycemic events were infrequent (2 [1%] vs 4 [3%], respectively). Conclusions and Relevance Among patients recently hospitalized with heart failure and reduced LVEF, the use of liraglutide did not lead to greater posthospitalization clinical stability. These findings do not support the use of liraglutide in this clinical situation. Trial Registration clinicaltrials.gov Identifier:NCT01800968

A wealth of genetic associations for cardiovascular and metabolic phenotypes in humans has been accumulating over the last decade, in particular a large number of loci derived from recent genome wide association studies (GWAS). True complex disease-associated loci often exert modest effects, so their delineation currently requires integration of diverse phenotypic data from large studies to ensure robust meta-analyses. We have designed a gene-centric 50 K single nucleotide polymorphism (SNP) array to assess potentially relevant loci across a range of cardiovascular, metabolic and inflammatory syndromes. The array utilizes a "cosmopolitan" tagging approach to capture the genetic diversity across approximately 2,000 loci in populations represented in the HapMap and SeattleSNPs projects. The array content is informed by GWAS of vascular and inflammatory disease, expression quantitative trait loci implicated in atherosclerosis, pathway based approaches and comprehensive literature searching. The custom flexibility of the array platform facilitated interrogation of loci at differing stringencies, according to a gene prioritization strategy that allows saturation of high priority loci with a greater density of markers than the existing GWAS tools, particularly in African HapMap samples. We also demonstrate that the IBC array can be used to complement GWAS, increasing coverage in high priority CVD-related loci across all major HapMap populations. DNA from over 200,000 extensively phenotyped individuals will be genotyped with this array with a significant portion of the generated data being released into the academic domain facilitating in silico replication attempts, analyses of rare variants and cross-cohort meta-analyses in diverse populations. These datasets will also facilitate more robust secondary analyses, such as explorations with alternative genetic models, epistasis and gene-environment interactions.

Failure of the human heart to maintain sufficient output of blood for the demands of the body, heart failure, is a common condition with high mortality even with modern therapeutic alternatives. To identify molecular determinants of mortality in patients with new-onset heart failure, we performed a meta-analysis of genome-wide association studies and follow-up genotyping in independent populations. We identified and replicated an association for a genetic variant on chromosome 5q22 with 36% increased risk of death in subjects with heart failure (rs9885413, P = 2.7x10⁻⁹. We provide evidence from reporter gene assays, computational predictions and epigenomic marks that this polymorphism increases activity of an enhancer region active in multiple human tissues. The polymorphism was further reproducibly associated with a DNA methylation signature in whole blood (P = 4.5x10⁻⁴⁰) that also associated with allergic sensitization and expression in blood of the cytokine TSLP (P = 1.1x10⁻⁴). Knockdown of the transcription factor predicted to bind the enhancer region (NHLH1) in a human cell line (HEK293) expressing NHLH1 resulted in lower TSLP expression. In addition, we observed evidence of recent positive selection acting on the risk allele in populations of African descent. Our findings provide novel genetic leads to factors that influence mortality in patients with heart failure., National Heart, Lung, and Blood Institute (HHSN268201100005C), National Heart, Lung, and Blood Institute (HHSN268201100006C), National Heart, Lung, and Blood Institute (HHSN268201100007C), National Heart, Lung, and Blood Institute (HHSN268201100008C), National Heart, Lung, and Blood Institute (HHSN268201100009C), National Heart, Lung, and Blood Institute (HHSN268201100010C), National Heart, Lung, and Blood Institute (HHSN268201100011C), National Heart, Lung, and Blood Institute (HHSN268201100012C), National Heart, Lung, and Blood Institute (N01-HC-55015), National Heart, Lung, and Blood Institute (N01-HC-55016), National Heart, Lung, and Blood Institute (N01-HC-55018), National Heart, Lung, and Blood Institute (N01-HC-55019), National Heart, Lung, and Blood Institute (N01-HC-55020), National Heart, Lung, and Blood Institute (N01-HC-55021), National Heart, Lung, and Blood Institute (N01-HC-55022), National Heart, Lung, and Blood Institute (R01HL087641), National Heart, Lung, and Blood Institute (R01HL59367), National Heart, Lung, and Blood Institute (R01HL086694), National Human Genome Research Institute (U.S.) (U01HG004402), United States. National Institutes of Health (HHSN268200625226C), United States. National Institutes of Health (UL1RR025005), National Heart, Lung, and Blood Institute (HHSN268201200036C), National Heart, Lung, and Blood Institute (N01HC55222), National Heart, Lung, and Blood Institute (HHSN268200800007C), National Heart, Lung, and Blood Institute (N01HC85079), National Heart, Lung, and Blood Institute (N01HC85080), National Heart, Lung, and Blood Institute (N01HC85081), National Heart, Lung, and Blood Institute (N01HC85082), National Heart, Lung, and Blood Institute (N01HC85083), National Heart, Lung, and Blood Institute (N01HC85086), National Heart, Lung, and Blood Institute (U01HL080295), National Science Foundation (U.S.) (R01HL087652), National Heart, Lung, and Blood Institute (R01HL105756), National Heart, Lung, and Blood Institute (R01HL103612), National Heart, Lung, and Blood Institute (R01HL120393), National Institute on Aging (R01AG023629), National Center for Advancing Translational Sciences (U.S.) (UL1TR000124), National Institute of Diabetes and Digestive and Kidney Diseases (U.S.) (DK063491), National Heart, Lung, and Blood Institute (N01-HC-25195), National Heart, Lung, and Blood Institute (2K24HL04334), National Heart, Lung, and Blood Institute (R01HL077477), National Heart, Lung, and Blood Institute (R01HL093328), National Heart, Lung, and Blood Institute (NIH R01HL105993), National Institute on Aging (N01AG62101), National Heart, Lung, and Blood Institute (N01AG62103), National Heart, Lung, and Blood Institute (N01AG62106), National Institute on Aging (1R01AG032098-01A1), United States. National Institutes of Health (HHSN268200782096C), National Cancer Institute (U.S.) (CA-34944), National Cancer Institute (U.S.) (CA-40360), National Cancer Institute (U.S.) (CA-097193), National Heart, Lung, and Blood Institute (HL-26490), National Heart, Lung, and Blood Institute (HL-34595)

Heart failure is a leading cause of mortality, yet our understanding of the genetic interactions underlying this disease remains incomplete. Here, we harvested 1352 healthy and failing human hearts directly from transplant center operating rooms, and obtained genome-wide genotyping and gene expression measurements for a subset of 313. We built failing and non-failing cardiac regulatory gene networks, revealing important regulators and cardiac expression quantitative trait loci (eQTLs).PPP1R3Aemerged as a novel regulator whose network connectivity changed significantly between health and disease. Time-course RNA sequencing afterPPP1R3Aknock-down validated network-based predictions of metabolic pathway expression, increased cardiomyocyte size, and perturbed respiratory metabolism. Mice lackingPPP1R3Awere protected against pressure-overload heart failure. We present a global gene interaction map of the human heart failure transition, identify new cardiac eQTLs, and demonstrate the discovery potential of disease-specific networks through the description ofPPP1R3Aas a novel central protective regulator in heart failure.

The molecular mechanisms that regulate and coordinate signaling between the extracellular matrix (ECM) and cells contributing to the developing vasculature are complex and poorly understood. Myocardin-like protein 2 (MKL2) is a transcriptional co-activator that in response to RhoA and cytoskeletal actin signals physically associates with serum response factor (SRF), activating a subset of SRF-regulated genes. We now report the discovery of a previously undescribed MKL2/TGFβ signaling pathway in embryonic stem (ES) cells that is required for maturation and stabilization of the embryonic vasculature. Mkl2–/– null embryos exhibit profound derangements in the tunica media of select arteries and arterial beds, which leads to aneurysmal dilation, dissection and hemorrhage. Remarkably, TGFβ expression, TGFβ signaling and TGFβ-regulated genes encoding ECM are downregulated in Mkl2–/– ES cells and the vasculature of Mkl2–/– embryos. The gene encoding TGFβ2, the predominant TGFβ isoform expressed in vascular smooth muscle cells and embryonic vasculature, is activated directly via binding of an MKL2/SRF protein complex to a conserved CArG box in the TGFβ2 promoter. Moreover, Mkl2–/– ES cells exhibit derangements in cytoskeletal organization, cell adhesion and expression of ECM that are rescued by forced expression of TGFβ2. Taken together, these data demonstrate that MKL2 regulates a conserved TGF-β signaling pathway that is required for angiogenesis and ultimately embryonic survival.

Transcriptomics is the study of how our genes are regulated and expressed in different biological settings. Technical advances now enable quantitative assessment of all expressed genes (ie, the entire “transcriptome”) in a given tissue at a given time. These approaches provide a powerful tool for understanding complex biological systems and for developing novel biomarkers. This chapter will introduce basic concepts in transcriptomics and available technologies for developing transcriptomic biomarkers. We will then review current and emerging applications in cardiovascular medicine.