Adeno-associated virus-mediated gene delivery of Perm1 enhances cardiac contractility in mice.

Reduced muscle contractility and mitochondrial bioenergetics are the hallmarks of systolic heart failure. There is currently no therapy targeting both. Here, we show that gene delivery of Perm1 via adeno-associated virus (AAV) simultaneously enhances cardiac contractility and mitochondrial biogenesis in C57BL6 mice. Moreover, we found that PERM1 interacts with troponin C (TnC), a key contractile protein in striated muscle, and that AAV-Perm1 led to the upregulation of TnC. This study suggests that gene delivery of Perm1 may be a novel therapeutic approach to treat systolic heart failure by simultaneously restoring cardiac contractility and mitochondrial bioenergetics.NEW & NOTEWORTHY Perm1 gene delivered with AAV9 enhances cardiac contractility in mice, and it is concomitant with the increase of mitochondrial bioenergetics and upregulation of TnC. This is the first study showing that PERM1, previously known as a striated muscle-specific mitochondrial regulator, also positively regulates cardiac contractility.

Genome-wide association analysis in dilated cardiomyopathy reveals two new players in systolic heart failure on chromosomes 3p25.1 and 22q11.23.

AIMS: Our objective was to better understand the genetic bases of dilated cardiomyopathy (DCM), a leading cause of systolic heart failure. METHODS AND RESULTS: We conducted the largest genome-wide association study performed so far in DCM, with 2719 cases and 4440 controls in the discovery population. We identified and replicated two new DCM-associated loci on chromosome 3p25.1 [lead single-nucleotide polymorphism (SNP) rs62232870, P = 8.7 × 10-11 and 7.7 × 10-4 in the discovery and replication steps, respectively] and chromosome 22q11.23 (lead SNP rs7284877, P = 3.3 × 10-8 and 1.4 × 10-3 in the discovery and replication steps, respectively), while confirming two previously identified DCM loci on chromosomes 10 and 1, BAG3 and HSPB7. A genetic risk score constructed from the number of risk alleles at these four DCM loci revealed a 3-fold increased risk of DCM for individuals with 8 risk alleles compared to individuals with 5 risk alleles (median of the referral population). In silico annotation and functional 4C-sequencing analyses on iPSC-derived cardiomyocytes identify SLC6A6 as the most likely DCM gene at the 3p25.1 locus. This gene encodes a taurine transporter whose involvement in myocardial dysfunction and DCM is supported by numerous observations in humans and animals. At the 22q11.23 locus, in silico and data mining annotations, and to a lesser extent functional analysis, strongly suggest SMARCB1 as the candidate culprit gene. CONCLUSION: This study provides a better understanding of the genetic architecture of DCM and sheds light on novel biological pathways underlying heart failure.

Experimental heart failure modelled by the cardiomyocyte-specific loss of an epigenome modifier, DNMT3B.

Differential DNA methylation exists in the epigenome of end-stage failing human hearts but whether it contributes to disease progression is presently unknown. Here, we report that cardiac specific deletion of Dnmt3b, the predominant DNA methyltransferase in adult mouse hearts, leads to an accelerated progression to severe systolic insufficiency and myocardial thinning without a preceding hypertrophic response. This was accompanied by widespread myocardial interstitial fibrosis and myo-sarcomeric disarray. By targeted candidate gene quantitative RT-PCR, we discovered an over-activity of cryptic splice sites in the sarcomeric gene Myh7, resulting in a transcript with 8 exons missing. Moreover, a region of differential methylation overlies the splice site locus in the hearts of the cardiac-specific conditional knockout (CKO) mice. Although abundant and complex forms of alternative splice variants have been reported in diseased hearts and the contribution of each remains to be understood in further detail, our results demonstrate for the first time that a link may exist between alternative splicing and the cardiac epigenome. In particular, this gives the novel evidence whereby the loss of an epigenome modifier promotes the development and progression of heart disease.

Effects of GRK5 and ADRB1 polymorphisms influence on systolic heart failure.

BACKGROUND: G-protein receptor kinase 5 (GRK5) Gln41 > Leu and ß1-adrenergic receptor (ADRB1) Arg389 > Gly polymorphisms presented the different distribution of genotype frequencies between Caucasian American and African American, and produced the difference in ß-blocker treatment effect among them with systolic heart failure (SHF). OBJECTIVE: This study sought to identify the distributed characteristics of these variant genotypes in Chinese population, and influence of GRK5 and ADRB1 polymorphisms on SHF morbidity and ß-blocker treatment effect in patients with SHF. METHODS: This study was based on cross-sectional survey data. 1794 and 1718 subjects' ADRB1 and GRK5 gene sequencing (sanger method) data were achieved respectively. Blood samples collection, clinical laboratory detection, electrocardiogram and echocardiography examinations were performed. Medication usage was confirmed at in-hospital visits or the questionnaire by personal interview. RESULTS: GRK5 Leu41Leu genotype was not found in our Chinese population. In non-SHF population, allele frequencies of GRK5 Gln41 and Leu41 were 2782 (0.992) and 22 (0.008) (Hardy-Weinberg equilibrium test χ(2) = 0.088, P = 0.767), and allele frequencies of ADRB1 Arg389 and Gly389 were 2127 (0.715) and 849 (0.285) (χ(2) = 0.272, P = 0.602). In SHF patients, allele frequencies of Gln41 and Leu41 were 446 (0.991) and 4 (0.009) (χ(2) = 0.018, P = 0.893), and allele frequencies of Arg389 and Gly389 were 331 (0.726) and 125 (0.274) (χ(2) = 1.892, P = 0.169). Further in logistic regression model, these ADRB1 and GRK5 variants were not significantly independently associated with the risk of SHF morbidity. Those carrying genotype ADRB1 Gly389Gly did not reduce significantly the risk of SHF morbidity after ß-blocker therapy. CONCLUSIONS: GRK5 Leu41Leu genotype was not found in our Chinese population, neither ADRB1 nor GRK5 variants presented independently associated with the risk of SHF morbidity, most ADRB1 and GRK5 polymorphisms did decrease significantly the risk of SHF morbidity after ß-blocker therapy except for those carrying genotype ADRB1 Gly389Gly.

Endothelial nitric oxide synthase polymorphism and prognosis in systolic heart failure patients.

BACKGROUND: The endothelial nitric oxide synthase (eNOS) gene single nucleotide polymorphism G894T is associated with thrombotic vascular diseases. However, its functional significance is controversial and data are scarce concerning its influence in heart failure (HF). METHODS: We studied 215 patients with chronic systolic HF. DNA was analyzed for eNOS gene G894T polymorphism using PCR and DNA sequencing. Evaluation of clinical characteristics and analysis of factors associated with 2-year mortality were performed for the homozygous G-allele G894T variant (GG), relative to the TT and GT variants. RESULTS: The genotype distributions of eNOS G894T alleles were: GG 135 patients (63%) and TT/GT 80 (37%). Two-year mortality was significantly higher in the GG variant (48%) than the combined TT/GT group (32%). The usage of nitrates was associated with increased 2-year mortality (HR 2.0, 95% CI 1.28-3.17; p = 0.003), which was most significant in the GG group treated with nitrates (73.5%) in comparison to the TT/GT group not treated with nitrates (34%); HR 2.75, 95% CI 1.57-4.79, P < 0.001. CONCLUSIONS: Homozygosity for the G allele of the eNOS G894T polymorphism was associated with worse survival in systolic HF patients, especially in those treated with nitrates. ENOS polymorphism may result in different mechanistic interactions in HF than in thrombotic vascular diseases, suggesting that overexpression of NO may be associated with deleterious effects in systolic HF.

Muscle ring finger-3 protects against diabetic cardiomyopathy induced by a high fat diet.

BACKGROUND: The pathogenesis of diabetic cardiomyopathy (DCM) involves the enhanced activation of peroxisome proliferator activating receptor (PPAR) transcription factors, including the most prominent isoform in the heart, PPARα. In cancer cells and adipocytes, post-translational modification of PPARs have been identified, including ligand-dependent degradation of PPARs by specific ubiquitin ligases. However, the regulation of PPARs in cardiomyocytes and heart have not previously been identified. We recently identified that muscle ring finger-1 (MuRF1) and MuRF2 differentially inhibit PPAR activities by mono-ubiquitination, leading to the hypothesis that MuRF3 may regulate PPAR activity in vivo to regulate DCM. METHODS: MuRF3-/- mice were challenged with 26 weeks 60% high fat diet to induce insulin resistance and DCM. Conscious echocardiography, blood glucose, tissue triglyceride, glycogen levels, immunoblot analysis of intracellular signaling, heart and skeletal muscle morphometrics, and PPARα, PPARß, and PPARγ1 activities were assayed. RESULTS: MuRF3-/- mice exhibited a premature systolic heart failure by 6 weeks high fat diet (vs. 12 weeks in MuRF3+/+). MuRF3-/- mice weighed significantly less than sibling-matched wildtype mice after 26 weeks HFD. These differences may be largely due to resistance to fat accumulation, as MRI analysis revealed MuRF3-/- mice had significantly less fat mass, but not lean body mass. In vitro ubiquitination assays identified MuRF3 mono-ubiquitinated PPARα and PPARγ1, but not PPARß. CONCLUSIONS: These findings suggest that MuRF3 helps stabilize cardiac PPARα and PPARγ1 in vivo to support resistance to the development of DCM. MuRF3 also plays an unexpected role in regulating fat storage despite being found only in striated muscle.

[Carriage of A Allele of Polymorphic Marker G(-238)A of TNF Gene Is Associated With Unfavorable Prognosis in Patients With Chronic Systolic Heart Failure].

AIM: to elucidate association between polymorphic markers of interleukin-6 (Il-6) and tumor necrosis factor (TNF) genes and unfavorable outcomes in patients with chronic heart failure (CHF). MATERIAL AND METHODS: We determined levels of TNF and Il-6 and genotypes of polymorphic markers G(-238)A of TNF gene (rs361525) and G(--174)C of IL-6 gene (rs1800795) in 151 patients (mean age 64.5 years) hospitalized because of decompensation of systolic CHF (left ventricular ejection fraction ≤ 40%) after stabilization of their state. Unfavorable outcomes were registered during follow-up for 2 years. RESULTS: Mean levels of NT-proBNP, Il-6, and TNF were 2481.1 ± 199.86 fmol/ml, 21.8 7.46 rg/ml, and 10.07 ± 0.65 rg/ml, respectively. 138 (94.4%), 13 (8.6%) and 0 patients were carriers of genotypes GG, AG, and AA of polymorphic marker G(-238)A of TNF gene, respectively; 54 (35.8%), 69 (45.7%), and 28 (18.5%) patients carried genotypes GG, GC, and CC of polymorphic marker G(-174)C gene IL-6, respectively. There was no association between Il-6, TNF levels and carriage of either of genotypes as well as unfavorable clinical course of CHF. Mean survival time before repetitive episode of CHF decompensation (including lethal one) was significantly shorter among carriers of A allele compared with carriers of G allele of polymorphic marker G(-238)A of TNF gene (243 ± 97.7 and 947 ± 78 days, respectively, p = 0.018). Mean time before all cause death was also shorter in carriers of A compared with carriers of G allele (289 ± 122.9 and 1039 ± 73.3 days, respectively, p = 0.03). The studied polymorphism of IL-6 gene had no prognostic value. CONCLUSION: We obtained data on association between carriage of A allele of polymorphic marker G(-238)A of TNF gene and unfavorable prognosis in patients with CHF and inpraired left ventricular systolic function.

The impact of coronary artery disease risk loci on ischemic heart failure severity and prognosis: association analysis in the COntrolled ROsuvastatin multiNAtional trial in heart failure (CORONA).

BACKGROUND: Recent genome-wide association studies have identified multiple loci that are associated with an increased risk of developing coronary artery disease (CAD). The impact of these loci on the disease severity and prognosis of ischemic heart failure due to CAD is currently unknown. METHODS: We undertook association analysis of 7 single nucleotide polymorphism (rs599839, rs17465637, rs2972147, rs6922269, rs1333049, rs501120, and rs17228212) at 7 well established CAD risk loci (1p13.3, 1q41, 2q36.3, 6q25.1, 9p21.3, 10q11.21, and 15q22.33, respectively) in 3,320 subjects diagnosed with systolic heart failure of ischemic aetiology and participating in the COntrolled ROsuvastatin multiNAtional Trial in Heart Failure (CORONA) trial. The primary outcome was the composite of time to first event of cardiovascular death, non-fatal myocardial infarction and non-fatal stroke, secondary outcomes included mortality and hospitalization due to worsening heart failure. RESULTS: None of the 7 loci were significantly associated with the primary composite endpoint of the CORONA trial (death from cardiovascular cases, nonfatal myocardial infarction, and nonfatal stroke). However, the 1p13.3 locus (rs599839) showed evidence for association with all-cause mortality (after adjustment for covariates; HR 0.74, 95%CI [0.61 to 0.90]; P = 0.0025) and we confirmed the 1p13.3 locus (rs599839) to be associated with lipid parameters (total cholesterol (P = 1.1x10(-4)), low-density lipoprotein levels (P = 3.5 × 10(-7)) and apolipoprotein B (P = 2.2 × 10(-10))). CONCLUSION: Genetic variants strongly associated with CAD risk are not associated with the severity and outcome of ischemic heart failure. The observed association of the 1p13.3 locus with all-cause mortality requires confirmation in further studies.

Pressure overload-induced systolic heart failure is associated with characteristic myocardial microRNA expression signature and post-transcriptional gene regulation in male rats.

Although systolic function characteristically shows gradual impairment in pressure overload (PO)-evoked left ventricular (LV) hypertrophy (LVH), rapid progression to congestive heart failure (HF) occurs in distinct cases. The molecular mechanisms for the differences in maladaptation are unknown. Here, we examined microRNA (miRNA) expression and miRNA-driven posttranscriptional gene regulation in the two forms of PO-induced LVH (with/without systolic HF). PO was induced by aortic banding (AB) in male Sprague-Dawley rats. Sham-operated animals were controls. The majority of AB animals demonstrated concentric LVH and slightly decreased systolic function (termed as ABLVH). In contrast, in some AB rats severely reduced ejection fraction, LV dilatation and increased lung weight-to-tibial length ratio was noted (referred to as ABHF). Global LV miRNA sequencing revealed fifty differentially regulated miRNAs in ABHF compared to ABLVH. Network theoretical miRNA-target analysis predicted more than three thousand genes with miRNA-driven dysregulation between the two groups. Seventeen genes with high node strength value were selected for target validation, of which five (Fmr1, Zfpm2, Wasl, Ets1, Atg16l1) showed decreased mRNA expression in ABHF by PCR. PO-evoked systolic HF is associated with unique miRNA alterations, which negatively regulate the mRNA expression of Fmr1, Zfmp2, Wasl, Ets1 and Atg16l1.

O-ring-induced transverse aortic constriction (OTAC) is a new simple method to develop cardiac hypertrophy and heart failure in mice.

Suture-based transverse aortic constriction (TAC) in mice is one of the most frequently used experimental models for cardiac pressure overload-induced heart failure. However, the incidence of heart failure in the conventional TAC depends on the operator's skill. To optimize and simplify this method, we proposed O-ring-induced transverse aortic constriction (OTAC) in mice. C57BL/6J mice were subjected to OTAC, in which an o-ring was applied to the transverse aorta (between the brachiocephalic artery and the left common carotid artery) and tied with a triple knot. We used different inner diameters of o-rings were 0.50 and 0.45 mm. Pressure overload by OTAC promoted left ventricular (LV) hypertrophy. OTAC also increased lung weight, indicating severe pulmonary congestion. Echocardiographic findings revealed that both OTAC groups developed LV hypertrophy within one week after the procedure and gradually reduced LV fractional shortening. In addition, significant elevations in gene expression related to heart failure, LV hypertrophy, and LV fibrosis were observed in the LV of OTAC mice. We demonstrated the OTAC method, which is a simple and effective cardiac pressure overload method in mice. This method will efficiently help us understand heart failure (HF) mechanisms with reduced LV ejection fraction (HFrEF) and cardiac hypertrophy.

The vasculature: a therapeutic target in heart failure?

It is well established that the vasculature plays a crucial role in maintaining oxygen and nutrients supply to the heart. Increasing evidence further suggests that the microcirculation has additional roles in supporting a healthy microenvironment. Heart failure is well known to be associated with changes and functional impairment of the microvasculature. The specific ablation of protective signals in endothelial cells in experimental models is sufficient to induce heart failure. Therefore, restoring a healthy endothelium and microcirculation may be a valuable therapeutic strategy to treat heart failure. This review article will summarize the current understanding of the vascular contribution to heart failure with reduced or preserved ejection fraction. Novel therapeutic approaches including next generation pro-angiogenic therapies and non-coding RNA therapeutics, as well as the targeting of metabolites or metabolic signalling, vascular inflammation and senescence will be discussed.

Systolic dysfunction in cardiac-specific ligand-inducible MerCreMer transgenic mice.

The Cre-loxP system is a useful tool to study the physiological effects of gene knockout in the heart. One limitation with using this system in the heart is the toxic effect of chronic expression of the Cre recombinase. To circumvent this limitation, a widely used inducible cardiac-specific model, Myh6-MerCreMer (Cre), using tamoxifen (TAM) to activate Cre has been developed. The current study examined cardiac function in Cre-positive C57B/J6 mice exposed to one, three, or five daily doses of a 40 mg/kg TAM to induce Cre activity specifically in the heart. Echocardiography demonstrated no statistically significant differences in systolic function (SF) at baseline as assessed by fractional shortening. In mice exposed to five injections, a significant fall in all determinants of SF was observed 6 days after TAM was initiated. However, SF returned to baseline levels 10 days after TAM initiation although the hearts exhibited significant hypertrophy. Heart weight-to-tibia length ratios were 73 ± 3, 78.5 ± 6, and 87.6 ± 9 mg/cm for one, three, and five TAM injections, respectively. TAM had no effect on cardiac function or hypertrophy in Cre-negative mice. Cre-positive mice receiving five TAM injections had significant reductions in cardiac mitochondrial ATP and significant reductions in the expression of proteins important for the regulation of cardiac oxidative phosphorylation including peroxisome proliferator-activated receptor-γ coactivator-1α and pyruvate dehydrogenase kinase-4. Thus inducible cardiac-specific activation of Cre recombinase caused a transient decline in SF that was dependent on the number of TAM doses and associated with significant hypertrophy and alterations in mitochondrial ATP and important proteins involved in the regulation of cardiac oxidative phosphorylation.

Polymorphisms of matrix metalloproteinases in systolic heart failure: role on disease susceptibility, phenotypic characteristics, and prognosis.

BACKGROUND: The role of matrix metalloproteinases (MMPs) polymorphisms on heart failure (HF) susceptibility, phenotypic characteristics, and prognosis has been poorly explored. METHODS AND RESULTS: We studied 313 HF patients with left ventricular systolic dysfunction and 367 healthy control subjects. Genotyping of MMP-1 (-1607 1G/2G), MMP-3 (-1171 5A/6A), and MMP-9 (-1562 C/T) polymorphisms was performed by polymerase chain reaction. Allelic and genotypic frequencies of MMP-1, -3, and -9 were similar in HF patients and controls. MMP1 2G allele carriers were positively associated to ischemic etiology and history of myocardial infarction (all P values <.05). Patients were followed-up for a median of 40 months and 58 HF-related deaths occurred during this period. HF-related survival was significantly better in MMP1 2G allele carriers (71% versus 42% for 1G/1G patients, P = .002) and in MMP-3 6A allele carriers (70% versus 61% for 5A/5A patients, P = .064), particularly in non-ischemic patients (P = .039). MMP1 2G allele was independently associated to HF survival after adjustment for several other predictors of risk (hazard ratio 0.47, 95% confidence interval 0.27 to 0.82; P = .008). CONCLUSIONS: MMP-1, -3, and -9 polymorphisms were not associated to HF susceptibility. However, MMP1 2G allele carriers were related to a higher prevalence of ischemic etiology among patients with systolic HF and better HF-related prognosis.

Association between genetic polymorphisms in the renin-angiotensin system and systolic heart failure revised by a propensity score-based analysis.

OBJECTIVES: The objective of this study is to identify possible genetic polymorphisms of the renin-angiotensin system (RAS) in systolic heart failure (sHF). METHODS: A total of 509 patients were enrolled into this study. A non-parsimonious multivariable logistic regression model that incorporated potential risk factors was applied to calculate the propensity score for developing sHF. A 1:1 case-control selection process was made according to the rank of propensity. The six genetic polymorphisms of angiotensinogen (AGT), including T174M, M235T, G-6A, A-20C, G-152A, and G-217A, and angiotensin-converting enzyme (ACE) gene I/D polymorphism were typed by polymerase chain reaction and DNA sequencing technique. RESULTS: The CC genotype at T174M was positively associated with sHF (OR 2.81, 95% CI 1.20-6.61, p = 0.018). The GG genotype at G-152A was also positively associated with the presence of sHF (OR 6.25, 95% CI 1.54-25.4, p = 0.010). OR of the ACE DD genotype for sHF, as compared with ACE II genotype, was 1.37 (p = 0.475), and OR for ID genotype compared with II genotype was 5.95 for sHF (95% CI 2.16-16.4, p = 0.001). CONCLUSIONS: The exploration of these RAS genes related to sHF may provide a more targeted and tailored treatment of sHF.

MicroRNA-183-3p up-regulated by vagus nerve stimulation mitigates chronic systolic heart failure via the reduction of BNIP3L-mediated autophagy.

Chronic systolic heart failure (CSHF) was a complex syndrome. Recently, vagus nerve stimulation (VNS), a novel treatment method, has emerged for the treatment of CSHF. therefore the aim of this study was to explore the possible mechanism of VNS treatment alleviating CSHF in rats. Firstly, we found after VNS treatment for 72 h, the level of B-type natriuretic peptide in VNS group was lower than that in CSHF group. In addition, VNS treatment induced the elevated left ventricular ejection fraction level, reduced left ventricular end diastolic volume and left ventricular end systolic volume level in VNS group, suggesting a mitigation of CSHF by VNS. Then we found the level of miR-183-3p in CSHF group was much lower than that in VNS group by High-throughput sequencing. The further results indicated that Bcl-2 interacting protein 3 like (BNIP3L) was identified as the target gene of miR-183-3p, and the expression of BNIP3L was notably reduced in rats of VNS group compared with CSHF group. Moreover, the down-regulated expression of miR-183-3p increased BNIP3L-mediated autophagy in rats of CSHF group compared with VNS group. Further mechanism findings demonstrated that up-regulation of miR-183-3p reduced the expression of BNIP3L, while down-regulation of miR-183-3p facilitated the expression of BNIP3L in H9c2 cells. miR-183-3p could also regulate autophagy by targeting BNIP3L in vitro, which was manifested by overexpression of miR-183-3p to inhibit BNIP3L-mediated autophagy. Our data demonstrated that VNS treatment benefited CSHF via the up-regulation of miRNA-183-3p, which reduced the BNIP3L-mediated autophagy, providing a new therapeutic direction for CSHF.

Liver-specific microRNA-122 as prognostic biomarker in patients with chronic systolic heart failure.

BACKGROUND: Circulating microRNAs (miRs) have been proposed as potential diagnostic biomarkers in heart failure. Studies investigating the prognostic value of circulating miRs in patients with chronic systolic heart failure (HFrEF) are scarce. The aim of this study was to investigate the prognostic value of circulating miRs in patients with HFrEF. METHODS AND RESULTS: A pathway-focused microRNA array was performed in derivation case-control cohort of 40 patients with HFrEF who died during the follow-up (cases) and 36 survivors (controls). MicroRNA expression profiling revealed significant differential expression of miR-122, miR-126 and miR-423 between cases and controls. In a validation cohort, circulating levels of these 3 miRs were assessed using qPCR in 234 patients with HFrEF. Primary study endpoints were all-cause and cardiovascular mortality. During a median follow-up time of 3.2 years, 76 patients (32.5%) died. Only miR-122 and miR-423 were independent predictors of the primary endpoint with respective hazard ratios per increase of one standard deviation (HR per 1-SD) of 1.14 (95% CI: 1.02-1.29, p = 0.021) and 1.24 (95% CI: 1.09-1.41, p = 0.001). Adding miR-122 to multivariable model including clinical risk factors and NT-proBNP improved net reclassification index (NRI) by 40.4% (p = 0.004), whereas miR-423 improved NRI by 35.3% (p = 0.012). Adding miR-122, but not miR-423, to the same model improved Harrell's C index from 0.78 (95% CI: 0.73-0.83) to 0.81 (95% CI: 0.76-0.86, p = 0.030). CONCLUSION: Circulating miR-122 as a biomarker is predicting all-cause and cardiovascular mortality and improved risk stratification of HFrEF patients. Thus, miR-122 might be a new biomarker for risk assessment in HFrEF.

Diastolic and systolic heart failure: different stages or distinct phenotypes of the heart failure syndrome?

It remains uncertain if diastolic heart failure (DHF) is a distinct HF phenotype or a precursor stage of systolic HF (SHF). The unimodal distribution of left ventricular ejection fraction (LVEF) in HF, depressed LV long-axis shortening in DHF, and progression to eccentric LV remodeling in hypertension favor DHF and SHF as successive stages. These arguments are countered by the bimodal distribution of LVEF after correction for gender, by the preserved LV twist in DHF and by the low incidence of eccentric LV remodeling in hypertension. Clinical features, LV anatomy and histology, cardiomyocyte stiffness, myocardial effects of diabetes, and the response to HF therapy support DHF and SHF as distinct phenotypes. Comparison of the myocardial signal transduction cascades that drive LV remodeling in DHF and SHF may solve the controversy. This review analyzes arguments supporting DHF and SHF as successive stages or distinct phenotypes of the HF syndrome.

Genotype-phenotype associations between chymase and angiotensin-converting enzyme gene polymorphisms in chronic systolic heart failure patients.

PURPOSE: Angiotensin II, which plays a crucial role in the myocardial remodeling process of heart failure, is generated via the angiotensin-converting enzyme and chymase pathways. We studied angiotensin-converting enzyme and chymase-1 polymorphisms in patients with systolic heart failure and the correlation with clinical status and left ventricular function. METHODS: We genotyped 195 patients with heart failure and systolic left ventricular dysfunction (ejection fraction <40%) for angiotensin-converting enzyme insertion (I)/deletion (D) and chymase-1 (-1903G/A) polymorphisms. Heart failure etiology and patients' clinical manifestations were analyzed in relation to genotype subtypes. RESULTS: The chymase-1 -1903 GG genotype was associated with a nonischemic heart failure etiology (chi = 6.67, P = 0.009). In the group of heart failure patients, the odds ratio of chymase-1 GG genotype having a nonischemic etiology was 2.48 (95% CI 1.23-5.00). The chymase-1 GG genotype was associated with lower ejection fraction (P = 0.005). Conversely, the angiotensin-converting enzyme D allele had no detectable impact on systolic heart failure phenotype. CONCLUSIONS: In patients with chronic systolic heart failure, the chymase-1 polymorphism was related to nonischemic etiology of heart failure. Patients homozygous for the G allele had a significantly greater reduction in systolic left ventricular function.

Genetics and genomics of dilated cardiomyopathy and systolic heart failure.

Heart failure is a major health burden, affecting 40 million people globally. One of the main causes of systolic heart failure is dilated cardiomyopathy (DCM), the leading global indication for heart transplantation. Our understanding of the genetic basis of both DCM and systolic heart failure has improved in recent years with the application of next-generation sequencing and genome-wide association studies (GWAS). This has enabled rapid sequencing at scale, leading to the discovery of many novel rare variants in DCM and of common variants in both systolic heart failure and DCM. Identifying rare and common genetic variants contributing to systolic heart failure has been challenging given its diverse and multiple etiologies. DCM, however, although rarer, is a reasonably specific and well-defined condition, leading to the identification of many rare genetic variants. Truncating variants in titin represent the single largest genetic cause of DCM. Here, we review the progress and challenges in the detection of rare and common variants in DCM and systolic heart failure, and the particular challenges in accurate and informed variant interpretation, and in understanding the effects of these variants. We also discuss how our increasing genetic knowledge is changing clinical management. Harnessing genetic data and translating it to improve risk stratification and the development of novel therapeutics represents a major challenge and unmet critical need for patients with heart failure and their families.

A functional variant of the neuropeptide S receptor-1 gene modulates clinical outcomes and healthcare utilization in patients with systolic heart failure: results from the Interdisciplinary Network Heart Failure (INH) Study.

AIMS: Psychopathologies may occur in heart failure (HF) and can be associated with adverse outcomes. Amongst neuropeptide S receptor gene functional sequence variants, the T-allele [asparagine(107)isoleucine, NPSR1 rs324981] has been identified as a risk factor for increased anxiety/overinterpretation of bodily symptoms. We investigated all-cause death and re-hospitalization (composite primary endpoint, CPEP) and healthcare utilization in patients hospitalized for decompensated systolic HF with the TT vs. the AT/AA genotype. METHODS AND RESULTS: Participants in the Interdisciplinary Network Heart Failure programme were eligible if consenting to genetic testing (n = 924) and randomization to usual care (UC, n = 464) or nurse-co-ordinated disease management (DM, n = 460). Follow-up was 180 days (100% complete). Compared with AT/AA carriers (n = 726), TT genotype carriers (n = 198) had more CPEP events [47% vs. 39%, hazard ratio (HR) 1.27, 95% confidence interval (CI) 1.01-1.61, P = 0.044] and were more frequently re-hospitalized (43% vs. 35%, HR 1.31, 95% CI 1.02-1.67, P = 0.033); mortality rate was similar in both groups (HR 1.11, 95% CI 0.68-1.81, P = 0.664). In subjects undergoing DM, CPEP and re-hospitalization occurred more often in TT (51% and 47%) than in AT/AA carriers (36% and 33%; HR 2.14, 95% CI 1.44-3.19, and HR 2.29, 95% CI 1.52-3.44, genotype/treatment interaction both P = 0.007). Furthermore, TT genotype carriers undergoing DM visited cardiologists and other specialists more often than AT/AA carriers (P = 0.009 and P = 0.005). With UC, event rates did not differ between genotype subgroups. CONCLUSION: We identified a psychogenetic determinant of clinical outcomes and healthcare utilization after acute HF, which was modulated by the type of care. Future investigations need to clarify whether NPSR1 genotyping might further enhance the concept of 'personalized' medicine in HF. TRIAL REGISTRATION: ISRCTN23325295.