Galectin-3 in heart failure with preserved ejection fraction. A RELAX trial substudy (Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in Diastolic Heart Failure)

Heart Failure With Preserved Ejection Fraction in the Elderly Population: Basic Mechanisms and Clinical Considerations

Heart failure with preserved ejection fraction (HFpEF) refers to a clinical condition in which the signs of heart failure, such as pulmonary congestion, peripheral edema, and increased natriuretic peptide levels, are present despite normal ejection fractions and the absence of other causes (eg, pericardial disease). The ejection fraction cutoff for the definition of HFpEF has varied in the past, but recent society guidelines have settled on a consensus of 50%. HFpEF is particularly common in the elderly population. The aim of this narrative review is to summarize the available literature regarding HFpEF in elderly patients in terms of evidence for the age dependence, specific clinical features, and underlying mechanisms. In the clinical arena, we review the epidemiology, discuss distinct clinical phenotypes typically seen in elderly patients, the importance of frailty, the role of biomarkers, and the role of medical therapies (including sodium-glucose cotransport protein 2 inhibitors, renin-angiotensin-aldosterone system blockers, angiotensin receptor/neprilysin inhibitors, diuretics, and β-adrenergic receptor blockers). We then go on to discuss the basic mechanisms implicated in HFpEF, including cellular senescence, fibrosis, inflammation, mitochondrial dysfunction, enhanced production of reactive oxygen species, abnormal cellular calcium handling, changes in microRNA signalling, insulin resistance, and sex hormone changes. Finally, we review knowledge gaps and promising areas of future investigation. Improved understanding of the specific clinical manifestations of HFpEF in elderly individuals and of the fundamental mechanisms that contribute to the age-related risk of HFpEF promises to lead to novel diagnostic and treatment approaches that will improve outcomes for this common cardiac disorder in a vulnerable population.

Identifying plasma proteomic signatures from health to heart failure, across the ejection fraction spectrum

Circulating proteins may provide insights into the varying biological mechanisms involved in heart failure (HF) with preserved ejection fraction (HFpEF) and reduced ejection fraction (HFrEF). We aimed to identify specific proteomic patterns for HF, by comparing proteomic profiles across the ejection fraction spectrum. We investigated 4210 circulating proteins in 739 patients with normal (Stage A/Healthy) or elevated (Stage B) filling pressures, HFpEF, or ischemic HFrEF (iHFrEF). We found 2122 differentially expressed proteins between iHFrEF-Stage A/Healthy, 1462 between iHFrEF-HFpEF and 52 between HFpEF-Stage A/Healthy. Of these 52 proteins, 50 were also found in iHFrEF vs. Stage A/Healthy, leaving SLITRK6 and NELL2 expressed in lower levels only in HFpEF. Moreover, 108 proteins, linked to regulation of cell fate commitment, differed only between iHFrEF-HFpEF. Proteomics across the HF spectrum reveals overlap in differentially expressed proteins compared to stage A/Healthy. Multiple proteins are unique for distinguishing iHFrEF from HFpEF, supporting the capacity of proteomics to discern between these conditions.

Correlates of Plasma NT-proBNP/Cyclic GMP Ratio in Heart Failure With Preserved Ejection Fraction: An Analysis of the RELAX Trial

BACKGROUND

Phosphodiesterases degrade cyclic GMP (cGMP), the second messenger that mediates the cardioprotective effects of natriuretic peptides. High natriuretic peptide/cGMP ratio may reflect, in part, phosphodiesterase activity. Correlates of natriuretic peptide/cGMP in patients with heart failure with preserved ejection fraction are not well understood. Among patients with heart failure with preserved ejection fraction in the RELAX (Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in Heart Failure With Preserved Ejection Fraction) trial, we examined (1) cross-sectional correlates of circulating NT-proBNP (N-terminal pro-B-type natriuretic peptide)/cGMP ratio, (2) whether selective phosphodiesterase-5 inhibition by sildenafil changed the ratio, and (3) whether the effect of sildenafil on 24-week outcomes varied by baseline ratio.

METHODS AND RESULTS

In 212 subjects, NT-proBNP/cGMP ratio was calculated at randomization and 24 weeks. Correlates of the ratio and its change were examined in multivariable proportional odds models. Whether baseline ratio modified the sildenafil effect on outcomes was examined by interaction terms. Higher NT-proBNP/cGMP ratio was associated with greater left ventricular mass and troponin, the presence of atrial fibrillation, and lower estimated glomerular filtration rate and peak oxygen consumption. Compared with placebo, sildenafil did not alter the ratio from baseline to 24 weeks (P=0.17). The effect of sildenafil on 24-week change in peak oxygen consumption, left ventricular mass, or clinical composite outcome was not modified by baseline NT-proBNP/cGMP ratio (P-interaction >0.30 for all).

CONCLUSIONS

Among patients with heart failure with preserved ejection fraction, higher NT-proBNP/cGMP ratio associated with an adverse cardiorenal phenotype, which was not improved by selective phosphodiesterase-5 inhibition. Other phosphodiesterases may be greater contributors than phosphodiesterase-5 to the adverse phenotype associated with a high natriuretic peptide/cGMP ratio in HFpEF.

REGISTRATION INFORMATION

clinicaltrials.gov. Identifier: NCT00763867.

Association of Urine Galectin-3 With Cardiorenal Outcomes in Patients With Heart Failure

BACKGROUND AND OBJECTIVES

Approaches to distinguishing pathological cardiorenal dysfunction in heart failure (HF) from functional/hemodynamically mediated changes in serum creatinine are needed. We investigated urine galectin-3 as a candidate biomarker of renal fibrosis and a prognostic indicator of cardiorenal dysfunction phenotypes.

METHODS

We measured urine galectin-3 in 2 contemporary HF cohorts: the Yale Transitional Care Clinic (YTCC) cohort (n = 132) and the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) trial (n = 434). We assessed the association of urine galectin-3 with all-cause mortality in both cohorts and the association with an established marker of renal tissue fibrosis, urinary amino-terminal propeptide of type III procollagen (PIIINP) in TOPCAT.

RESULTS

In the YTCC cohort, there was significant effect modification between higher urine galectin-3 and lower estimated glomerular filtration rates (eGFRs) (Pinteraction = 0.046), such that low eGFR levels had minimal prognostic importance if urine galectin-3 levels were low, but they were important and indicated high risk if urine galectin-3 levels were high. Similar observations were noted in the TOPCAT study (Pinteraction = 0.002). In TOPCAT, urine galectin-3 also positively correlated with urine PIIINP at both baseline (r = 0.43; P < 0.001) and at 12 months (r = 0.42; P < 0.001).

CONCLUSIONS

Urine galectin-3 levels correlated with an established biomarker of renal fibrosis in 2 cohorts and was able to differentiate high- vs low-risk phenotypes of chronic kidney disease in HF. These proof-of-concept results indicate that additional biomarker research to differentiate cardiorenal phenotypes is warranted.

The immunology of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) now accounts for the majority of new heart failure diagnoses and continues to increase in prevalence in the United States. Importantly, HFpEF is a highly morbid, heterogeneous syndrome lacking effective therapies. Inflammation has emerged as a potential contributor to the pathogenesis of HFpEF. Many of the risk factors for HFpEF are also associated with chronic inflammation, such as obesity, hypertension, aging, and renal dysfunction. A large amount of preclinical evidence suggests that immune cells and their associated cytokines play important roles in mediating fibrosis, oxidative stress, metabolic derangements, and endothelial dysfunction, all potentially important processes in HFpEF. How inflammation contributes to HFpEF pathogenesis, however, remains poorly understood. Recently, a variety of preclinical models have emerged which may yield much needed insights into the causal relationships between risk factors and the development of HFpEF, including the role of specific immune cell subsets or inflammatory pathways. Here, we review evidence in animal models and humans implicating inflammation as a mediator of HFpEF and identify gaps in knowledge requiring further study. As the understanding between inflammation and HFpEF evolves, it is hoped that a better understanding of the mechanisms underlying immune cell activation in HFpEF can open up new therapeutic avenues.

Hypermethylation of ACADVL is involved in the high-intensity interval training-associated reduction of cardiac fibrosis in heart failure patients

BACKGROUND

Emerging evidence suggests that DNA methylation can be affected by physical activities and is associated with cardiac fibrosis. This translational research examined the implications of DNA methylation associated with the high-intensity interval training (HIIT) effects on cardiac fibrosis in patients with heart failure (HF).

METHODS

Twelve HF patients were included and received cardiovascular magnetic resonance imaging with late gadolinium enhancement for cardiac fibrosis severity and a cardiopulmonary exercise test for peak oxygen consumption ([Formula: see text]O_2peak). Afterwards, they underwent 36 sessions of HIIT at alternating 80% and 40% of [Formula: see text]O_2peak for 30 min per session in 3-4 months. Human serum from 11 participants, as a means to link cell biology to clinical presentations, was used to investigate the exercise effects on cardiac fibrosis. Primary human cardiac fibroblasts (HCFs) were incubated in patient serum, and analyses of cell behaviour, proteomics (n = 6) and DNA methylation profiling (n = 3) were performed. All measurements were conducted after completing HIIT.

RESULTS

A significant increase (p = 0.009) in [Formula: see text]O_2peak (pre- vs. post-HIIT = 19.0 ± 1.1 O₂ ml/kg/min vs. 21.8 ± 1.1 O₂ ml/kg/min) was observed after HIIT. The exercise strategy resulted in a significant decrease in left ventricle (LV) volume by 15% to 40% (p < 0.05) and a significant increase in LV ejection fraction by approximately 30% (p = 0.010). LV myocardial fibrosis significantly decreased from 30.9 ± 1.2% to 27.2 ± 0.8% (p = 0.013) and from 33.4 ± 1.6% to 30.1 ± 1.6% (p = 0.021) in the middle and apical LV myocardium after HIIT, respectively. The mean single-cell migration speed was significantly (p = 0.044) greater for HCFs treated with patient serum before (2.15 ± 0.17 μm/min) than after (1.11 ± 0.12 μm/min) HIIT. Forty-three of 1222 identified proteins were significantly involved in HIIT-induced altered HCF activities. There was significant (p = 0.044) hypermethylation of the acyl-CoA dehydrogenase very long chain (ACADVL) gene with a 4.474-fold increase after HIIT, which could activate downstream caspase-mediated actin disassembly and the cell death pathway.

CONCLUSIONS

Human investigation has shown that HIIT is associated with reduced cardiac fibrosis in HF patients. Hypermethylation of ACADVL after HIIT may contribute to impeding HCF activities. This exercise-associated epigenetic reprogramming may contribute to reduce cardiac fibrosis and promote cardiorespiratory fitness in HF patients.

TRIAL REGISTRATION

NCT04038723. Registered 31 July 2019, https://clinicaltrials.gov/ct2/show/NCT04038723 .

Defining the Phenotypes for Heart Failure With Preserved Ejection Fraction

PURPOSE OF REVIEW

Heart failure with preserved ejection fraction (HFpEF) imposes a significant burden on society and healthcare. The lack in efficacious therapies is likely due to the significant heterogeneity of HFpEF. In this review, we define various phenotypes based on underlying comorbidities or etiologies, discuss phenotypes arrived at by novel methods, and explore therapeutic targets.

RECENT FINDINGS

A few studies have used machine learning methods to uncover sub-phenotypes within HFpEF in an unbiased manner based on clinical features, echocardiographic findings, and biomarker levels. We synthesized the literature and propose three broad phenotypes: (1) young, with few comorbidities, usually obese and with low natriuretic peptide levels, (2) obese with substantive cardiometabolic burden and comorbidities and impaired ventricular relaxation, (3) old, multimorbid, with high rates of atrial fibrillation, renal and coronary artery disease, chronic obstructive pulmonary disease, and left ventricular hypertrophy. We also propose potential therapeutic strategies for these phenotypes.

Galectin 3 and non-classical monocytes of blood as myocardial remodeling factors at ischemic cardiomyopathy

Aims

To identify an imbalance of cardiac remodeling mediators and monocytes subpopulation in blood, distribution of myocardium macrophages in patients with ischemic cardiomyopathy (ICMP).

Methods

The study engaged 30 patients with ICMP, 26 patients with coronary heart disease (CHD) without ICMP, 15 healthy donors. Concentrations of TGFβ, MMP-9, MCP-1, galectin-3 were measured in plasma of blood from the coronary sinus and peripheral blood in CHD patients, as well as in peripheral blood in healthy donors, by enzyme immunoassay method. The ration of classical, intermediate, non-classical, transitional monocytes in peripheral blood of patients and healthy donors was assessed by flow cytometry (expression CD14, CD16); the content of CD68+ macrophages in myocardium – by immunohistochemistry method.

Results

In both samples of blood, the content of galectin-3 in patients with ICMP was higher than in CHD patients without ICMP and the level of TGFβ was comparable between the groups. At ICMP, the concentration of MMP-9 in sinus blood was higher than that in CHD patients without ICMP in whom an excess of MCP-1 in the general blood flow was determined. The density of distribution of CD68+ cells in the myocardium in patients with ICMP was higher in the perianeurysmal zone than in the right atrium appendage. ICMP was characterized by a deficiency of non-classical monocytes, and CHD without ICMP – by an excess of intermediate cells in peripheral blood.

Conclusion

Myocardium remodeling at ICMP is mediated by not so much TGFβ but intracardiac galectin-3, which determines the subpopulation composition of blood monocytes.

The prognostic value of diastolic and systolic mechanical left ventricular dyssynchrony among patients with coronary artery disease and heart failure

BACKGROUND

Prevalence and prognostic value of diastolic and systolic dyssynchrony in patients with coronary artery disease (CAD) + heart failure (HF) or CAD alone are not well understood.

METHODS

We included patients with gated single-photon emission computed tomography (GSPECT) myocardial perfusion imaging (MPI) between 2003 and 2009. Patients had at least one major epicardial obstruction ≥ 50%. We assessed the association between dyssynchrony and outcomes, including all-cause and cardiovascular death.

RESULTS

Of the 1294 patients, HF was present in 25%. Median follow-up was 6.7 years (IQR 4.9-9.3) years with 537 recorded deaths. Patients with CAD + HF had a higher incidence of dyssynchrony than patients with CAD alone (diastolic BW 28.8% for the HF + CAD vs 14.7% for the CAD alone). Patients with CAD + HF had a lower survival than CAD alone at 10 years (33%; 95% CI 27-40 vs 59; 95% CI 55-62, P < 0.0001). With one exception, HF was found to have no statistically significant interaction with dyssynchrony measures in unadjusted and adjusted survival models.

CONCLUSIONS

Patients with CAD + HF have a high prevalence of mechanical dyssynchrony as measured by GSPECT MPI, and a higher mortality than CAD alone. However, clinical outcomes associated with mechanical dyssynchrony did not differ in patients with and without HF.

Obese-Inflammatory Phenotypes in Heart Failure With Preserved Ejection Fraction

BACKGROUND

Comorbidity-driven microvascular inflammation is posited as a unifying pathophysiologic mechanism for heart failure with preserved ejection fraction (HFpEF). Obesity is proinflammatory and common in HFpEF. We hypothesized that unique obesity-inflammation HFpEF phenotypes exist and are associated with differences in clinical features, fibrosis biomarkers, and functional performance.

METHODS

Patients (n=301) from 3 HFpEF clinical trials were studied. Unsupervised machine learning (hierarchical clustering) with obese status and 13 inflammatory biomarkers as input variables was performed. Associations of clusters with HFpEF severity and fibrosis biomarkers (PIIINP [procollagen III N-terminal peptide], CITP [C-telopeptide for type I collagen], IGFBP7 [insulin-like growth factor-binding protein-7], and GAL-3 [galectin-3]) were assessed.

RESULTS

Hierarchical clustering revealed 3 phenotypes: pan-inflammatory (n=129; 64% obese), noninflammatory (n=83; 55% obese), and obese high CRP (C-reactive protein; n=89; 98% obese). The pan-inflammatory phenotype had more comorbidities and heart failure hospitalizations; higher left atrial volume, NT-proBNP (N-terminal pro-B-type natriuretic peptide), and fibrosis biomarkers; and lower glomerular filtration rate, peak oxygen consumption, 6-minute walk distance, and active hours/day (P<0.05 for all). The noninflammatory phenotype had the most favorable values for all measures. The obese high CRP phenotype resembled the noninflammatory phenotype except for isolated elevation of CRP and lower functional performance. Hierarchical cluster assignment was independent of CRP genotype combinations that alter CRP levels and more biologically plausible than other clustering approaches. Multiple traditional analytic techniques confirmed and extended the hierarchical clustering findings.

CONCLUSIONS

Unique obesity-inflammation phenotypes exist in HFpEF and are associated with differences in comorbidity burden, HFpEF severity, and fibrosis. These data support comorbidity-driven microvascular inflammation as a pathophysiologic mechanism for many but not all HFpEF patients.

Association of Cardiac Biomarkers With the Kansas City Cardiomyopathy Questionnaire in Patients With Chronic Kidney Disease Without Heart Failure

Background The Kansas City Cardiomyopathy Questionnaire (KCCQ) is a measure of heart failure (HF) health status. Worse KCCQ scores are common in patients with chronic kidney disease (CKD), even without diagnosed heart failure (HF). Elevations in the cardiac biomarkers GDF-15 (growth differentiation factor-15), galectin-3, sST2 (soluble suppression of tumorigenesis-2), hsTnT (high-sensitivity troponin T), and NT-proBNP (N-terminal pro-B-type natriuretic peptide) likely reflect subclinical HF in CKD. Whether cardiac biomarkers are associated with low KCCQ scores is not known. Methods and Results We studied participants with CKD without HF in the multicenter prospective CRIC (Chronic Renal Insufficiency Cohort) Study. Outcomes included (1) low KCCQ score <75 at year 1 and (2) incident decline in KCCQ score to <75. We used multivariable logistic regression and Cox regression models to evaluate the associations between baseline cardiac biomarkers and cross-sectional and longitudinal KCCQ scores. Among 2873 participants, GDF-15 (adjusted odds ratio 1.42 per SD; 99% CI, 1.19-1.68) and galectin-3 (1.28; 1.12-1.48) were significantly associated with KCCQ scores <75, whereas sST2, hsTnT, and NT-proBNP were not significantly associated with KCCQ scores <75 after multivariable adjustment. Of the 2132 participants with KCCQ ≥75 at year 1, GDF-15 (adjusted hazard ratio, 1.36 per SD; 99% CI, 1.12-1.65), hsTnT (1.20; 1.01-1.44), and NT-proBNP (1.30; 1.08-1.56) were associated with incident decline in KCCQ to <75 after multivariable adjustment, whereas galectin-3 and sST2 did not have significant associations with KCCQ decline. Conclusions Among participants with CKD without clinical HF, GDF-15, galectin-3, NT-proBNP, and hsTnT were associated with low KCCQ either at baseline or during follow-up. Our findings show that elevations in cardiac biomarkers reflect early symptomatic changes in HF health status in CKD patients.

The utility of growth differentiation factor-15, galectin-3, and sST2 as biomarkers for the diagnosis of heart failure with preserved ejection fraction and compared to heart failure with reduced ejection fraction: a systematic review

The objective was to evaluate the diagnosis of heart failure with preserved ejection fraction (HFpEF) using the biomarkers, growth differentiation factor-15 (GDF-15), galectin-3 (Gal-3), and soluble ST2 (sST2), and to determine whether they can differentiate HFpEF from heart failure with reduced ejection fraction (HFrEF). Medline and Embase databases were searched with the terms diastolic heart failure or HFpEF, biomarkers, and diagnosis, limited to years 2000 to 2019. There were significantly and consistently higher levels of GDF-15, Gal-3, and sST2 in HFpEF compared to no heart failure. Importantly, the magnitude of the increase in GDF-15 or Gal-3 and possibly sST2,correlated with a greater degree of diastolic dysfunction. There were no significant differences between GDF-15, Gal-3, and sST2 in patients with HFpEF vs HFrEF. In the studies assessing these three biomarkers, BNP was significantly greater in heart failure than controls. Furthermore, BNP was significantly higher in HFrEF compared to HFpEF. The diagnostic utility of GDF-15, Gal-3, and sST2 compared to BNP was evaluated by comparing ROC curves. The data supports the contention that to distinguish HFpEF from HFrEF, an index is needed that incorporates GDF-15, Gal-3, or sST2 as well as BNP. The three biomarkers GDF-15, Gal-3, or sST2 can identify patients with HFpEF compared to individuals without heart failure but cannot differentiate HFpEF from HFrEF. BNP is higher in and is better at differentiating HFrEF from HFpEF. Indices that incorporate GDF-15, Gal-3, or sST2 as well as BNP show promise in differentiating HFpEF from HFrEF.

Are existing and emerging biomarkers associated with cardiorespiratory fitness in patients with chronic heart failure?

BACKGROUND

Cardiorespiratory fitness (CRF) is closely linked to health status and clinical outcomes in heart failure (HF) patients. We aimed to test whether biomarkers can reflect CRF and its change over time.

METHODS

This post hoc analysis used data from ambulatory cohorts of heart failure with reduced ejection fraction (HFrEF) (IRONOUT) and heart failure with preserved ejection fraction (HFpEF) (RELAX). Cardiopulmonary exercise testing, 6-minute walk distance (6MWD), and serum biomarkers were measured at baseline and 16- or 24-week follow-up (for IRONOUT and RELAX respectively). Biomarkers included N-terminal pro-B-type natriuretic peptide (NT-proBNP), soluble ST2, growth differentiation factor-15, and Galectin-3.

RESULTS

Analysis included 225 patients with HFrEF and 216 with HFpEF. Baseline peak VO₂, VE/VCO₂ slope, and 6MWD showed a mild correlation with the doubling of all 4 tested biomarkers in HFrEF and HFpEF. Following multivariable adjustment (including all biomarkers), the only significant association between change in biomarker and functional parameter in HFrEF was change in NT-proBNP and change in VE/VCO₂ slope (3.596% increase per doubling, 95% CI 0.779-6.492, P = .012). In HFpEF, a decrease in peak VO₂ was associated with an increase in NT-proBNP (-0.726 mL/min/kg per doubling, 95% CI -1.100 to -0.353, P < .001), and a decrease in 6MWD was associated with an increase in growth differentiation factor-15 (-31.606 m per doubling, 95% CI -61.404 to -1.809, P = .038).

CONCLUSIONS

In these ambulatory trial cohorts, NT-proBNP was associated with baseline and change in CRF in HFrEF and HFpEF. In contrast, novel biomarkers do not appear suitable as a reliable surrogate for serial assessment of exercise capacity in HF patients given lack of consistent independent association with CRF beyond traditional risk factors and NT-proBNP.

Renal Dysfunction in Heart Failure With Preserved Ejection Fraction: Insights From the RELAX Trial

BACKGROUND

Patients with heart failure with preserved ejection fraction (HFpEF) and chronic kidney disease (CKD) represent a high-risk phenotype. The Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in Heart Failure with Preserved Ejection Fraction (RELAX) trial enrolled a high proportion of CKD participants, allowing investigation into differences in HFpEF by CKD status.

METHODS AND RESULTS

Among 212 participants, we investigated the associations of CKD with biomarkers, cardiac structure, and exercise capacity, and identified predictors of change in estimated glomerular filtration rate (eGFR) over trial follow-up. CKD participants (eGFR ≤60 mL/min/1.73m²) were older, had more comorbidities, and had worse diastolic function. Lower eGFR was associated with higher levels of endothelin-1, N-terminal pro-B-type natriuretic peptide, aldosterone, uric acid, and biomarkers of fibrosis (P < .05 for all). Whereas lower eGFR was associated with worse peak oxygen consumption (VO₂) after adjustment for demographics, clinical comorbidities, exercise modality, ejection fraction, and chronotropic index (β coefficient per 1 SD decrease in eGFR: -0.61, 95% CI: -1.01, -0.22, P = .002), this association was attenuated after further adjustment for hemoglobin (β coefficient: -0.26, 95% CI: -0.68, 0.16, P = .22). Hemoglobin mediated 35% of the association between eGFR and peak VO₂. Sildenafil therapy was independently associated with worsening eGFR over the trial (β coefficient: -2.79, 95% CI: -5.34, -0.24, P = .03).

CONCLUSION

Renal dysfunction in HFpEF is characterized by echocardiographic and biomarker profiles indicative of more advanced disease, and reduced hemoglobin is a strong mediator of the association between renal dysfunction and low exercise capacity. Sildenafil therapy was associated with worsening of renal function in RELAX.

β-Adrenoceptor activation affects galectin-3 as a biomarker and therapeutic target in heart disease

Myocardial fibrosis is a key histopathological component that drives the progression of heart disease leading to heart failure and constitutes a therapeutic target. Recent preclinical and clinical studies have implicated galectin-3 (Gal-3) as a pro-fibrotic molecule and a biomarker of heart disease and fibrosis. However, our knowledge is poor on the mechanism(s) that determine the blood level or regulate cardiac expression of Gal-3. Recent studies have demonstrated that enhanced β-adrenoceptor activity is a determinant of both circulating concentration and cardiac expression of Gal-3. Pharmacological or transgenic activation of β-adrenoceptors leads to increased blood levels of Gal-3 and up-regulated cardiac Gal-3 expression, effect that can be reversed with the use of β-adrenoceptor antagonists. Conversely, Gal-3 gene deletion confers protection against isoprenaline-induced cardiotoxicity and fibrogenesis. At the transcription level, β-adrenoceptor stimulation activates cardiac mammalian sterile-20-like kinase 1, a pivotal kinase of the Hippo signalling pathway, which is associated with Gal-3 up-regulation. Recent studies have suggested a role for the β-adrenoceptor-Hippo signalling pathway in the regulation of cardiac Gal-3 expression thereby contributing to the onset and progression of heart disease. This implies a therapeutic potential of the suppression of Gal-3 expression. In this review, we discuss the effects of β-adrenoceptor activity on Gal-3 as a biomarker and causative mediator in the setting of heart disease and point out pivotal knowledge gaps. LINKED ARTICLES: This article is part of a themed section on Adrenoceptors-New Roles for Old Players. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.14/issuetoc.

Characterization of the Obese Phenotype of Heart Failure With Preserved Ejection Fraction: A RELAX Trial Ancillary Study

OBJECTIVE

To characterize the obese heart failure with preserved ejection fraction (HFpEF) phenotype in a multicenter cohort.

PATIENTS AND METHODS

This was a secondary analysis of the randomized clinical trial RELAX (Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in Heart Failure with Preserved Ejection Fraction) performed between October 1, 2008, and February 1, 2012. Patients with HFpEF were classified by body mass index (BMI) as obese (BMI≥35 kg/m²) and nonobese (BMI<30 kg/m²) for comparison.

RESULTS

Obese patients with HFpEF (n=81) were younger (median age, 64 [interquartile range (IQR), 67-79] years vs 73 [IQR, 56-70] years; P<.001) but had greater peripheral edema (31% [25] vs 9% [6]; P<.001), more orthopnea (76% [56] vs 53% [35]; P=.005), worse New York Heart Association class (P=.006), and more impaired quality of life (P<.001) as compared with nonobese patients with HFpEF (n=70). Despite more severe signs and symptoms, obese patients with HFpEF had lower N-terminal pro B-type natriuretic peptide level (median, 481 [IQR, 176-1183] pg/mL vs 825 [IQR, 380-1679] pg/mL [to convert to pmol/L, multiply by 0.118]; P=.007) and lower left atrial volume index (median, 38 [IQR, 31-47] mL/m² vs 54 [IQR, 41-63] mL/m²; P<.001). Serum C-reactive protein (median, 5.0 [IQR, 2.4-9.9] mg/dL vs 2.7 [IQR, 1.6-5.4] mg/dL [to convert to mg/L, multiply by 10^-3]; P<.001) and uric acid (median, 7.8 [IQR, 6.1-8.7] mg/dL vs 6.8 [IQR, 5.5-8.3] mg/dL; P=.03) levels were higher in obese HFpEF, indicating greater systemic inflammation, than in nonobese HFpEF. Peak oxygen consumption was impaired in obese HFpEF (median, 11.1 [IQR, 9.6-14.4] mL/kg per minute vs 13.1 [IQR, 11.3-14.7] mL/kg per minute; P=.008), as was submaximal exercise capacity (6-minute walk distance, 272 [IQR, 200-332] m vs 355 [IQR, 290-415] m; P<.0001).

CONCLUSION

Obese HFpEF is associated with decreased quality of life, worse symptoms of heart failure, greater systemic inflammation, worse exercise capacity, and higher metabolic cost of exertion as compared with nonobese HFpEF. Further study is required to understand the pathophysiology and potential distinct treatments for patients with the obese phenotype of HFpEF.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00763867.

Biomarkers in Routine Heart Failure Clinical Care

Heart failure is a clinical condition with complex pathophysiology that involves many different processes. Diagnosis is often difficult in patients presenting for the first time with breathlessness. Many biomarkers have been identified that are elevated in heart failure and their role in assessing prognosis has also been investigated. However, at present the natriuretic peptides appear to be the gold standard biomarker against which the other biomarkers are compared. In this review we will examine the evidence behind the other biomarkers for use in heart failure patients and the current guidelines for their use.

Acute cardiac dyspnea in the emergency department: diagnostic value of N-terminal prohormone of brain natriuretic peptide and galectin-3

OBJECTIVE

This study was performed to determine whether a dual-biomarker approach using N-terminal prohormone of brain natriuretic peptide (NT-proBNP) and galectin-3 optimizes the diagnosis and risk stratification of acute cardiac dyspnea. Atypical clinical manifestations and overlapping pathologies require objective and effective diagnostic methods to avoid treatment delays.

METHODS

This prospective observational study included 208 patients who presented to the emergency department for acute dyspnea. NT-proBNP and galectin-3 were measured upon admission. The patients were divided into two groups according to the etiology of their clinical manifestations: cardiac and non-cardiac dyspnea. The patients' New York Heart Association functional class, left ventricular ejection fraction, and discharge status were assessed.

RESULTS

Diagnostic criteria for acute heart failure were fulfilled in 61.1% of the patients. NT-proBNP and galectin-3 were strongly and significantly correlated. Receiver operating characteristic analysis revealed similar areas under the curve for both markers in the entire group of patients as well as in the high-risk subsets of patients.

CONCLUSIONS

The diagnostic performance of NT-proBNP and galectin-3 is comparable for both the total population and high-risk subsets. Galectin-3 adds diagnostic value to the conventional NT-proBNP in patients with acute cardiac dyspnea, and its utility is of major interest in uncertain clinical situations.

Galectin-3 Reflects the Echocardiographic Grades of Left Ventricular Diastolic Dysfunction

Background

The level of Galectin-3 (Gal-3) protein purportedly reflects an ongoing cardiac fibrotic process and has been associated with ventricular remodeling, which is instrumental in the development of heart failure with preserved ejection fraction (HFpEF) syndrome. The aim of this study was to investigate the potential use of Gal-3 in improved characterization of the grades of diastolic dysfunction as defined by echocardiography.

Methods

Seventy HFpEF patients undergoing routine echocardiography were prospectively enrolled in the present monocentric study. Blood samples for measurements of Gal-3 and amino-terminal pro-brain natriuretic peptide (NT-proBNP) were collected within 24 hours pre- or post-echocardiographic examination. The classification of patients into subgroups based on diastolic dysfunction grade permitted detailed statistical analyses of the derived data.

Results

The Gal-3 serum levels of all patients corresponded to echocardiographic indices, suggesting HFpEF (E/A, P=0.03 and E/E', P=0.02). Gal-3 was also associated with progressive diastolic dysfunction, and increased levels corresponded to the course of disease (P=0.012). Detailed analyses of ROC curves suggested that Gal-3 levels could discriminate patients with grade III diastolic dysfunction (area under the curve [AUC]=0.770, P=0.005).

Conclusions

Gal-3 demonstrates remarkable effectiveness in the diagnosis of patients suffering from severe grade diastolic dysfunction. Increasing levels of Gal-3 possibly reflect the progressive course of HFpEF, as classified by the echocardiographic grades of diastolic dysfunction.

High-sensitivity C-reactive protein in heart failure with preserved ejection fraction

Background

Microvascular inflammation may contribute to the pathogenesis of both heart failure with preserved ejection fraction (HFpEF) and pulmonary hypertension (PH). We investigated whether the inflammation biomarker C-reactive protein (CRP) was associated with clinical characteristics, disease severity or PH in HFpEF.

Methods

Patients in the Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in Diastolic Heart failure (RELAX) trial had baseline high-sensitivity CRP levels measured (n = 214). Clinical characteristics, exercise performance, echocardiographic variables and biomarkers of neurohumoral activation, fibrosis and myocardial necrosis were assessed. Patients with normal (≤3mg/L) versus high (>3mg/L) CRP levels were compared.

Results

The median CRP level was 3.69mg/L. CRP was elevated in 57% of patients. High CRP levels were associated with younger age, higher body mass index (BMI), chronic obstructive pulmonary disease (COPD), lower peak oxygen consumption and higher endothelin-1 and aldosterone levels. CRP increased progressively with the number of comorbidities (0.7mg/L per increment in comorbidity number, P = 0.02). Adjusting for age, BMI and statin use, high CRP levels were additionally associated with atrial fibrillation, right ventricular dysfunction, and higher N-terminal pro-B-type natriuretic peptide levels (P<0.05 for all). CRP was not associated with PH or left ventricular function. CRP did not identify responders to sildenafil(P-value for interaction 0.13).

Conclusions

In HFpEF, high CRP is associated with greater comorbidity burden and some markers of disease severity but CRP was normal in 40% of patients. These findings support the presence of comorbidity-driven systemic inflammation in HFpEF but also the need to study other biomarkers which may better reflect the presence of systemic inflammation.

Non-natriuretic peptide biomarkers in heart failure with preserved and reduced ejection fraction

Heart failure (HF) with reduced and preserved ejection fraction constitutes two entities with distinct pathogenetic backgrounds sharing common features. Beyond natriuretic peptides, several novel biomarkers have been proven useful in the diagnosis, prognosis and treatment of HF. Biomarkers of myocardial fibrosis have a low diagnostic yield in subjects with acute HF but may add prognostic information, especially in patients with HF and preserved ejection fraction. Biomarkers of renal impairment identify subjects with worse prognosis independently of left ventricle ejection fraction while inflammatory markers have not been proven useful in patients with systolic or diastolic impairment. In this review article, we summarize the main differences and application of non-natriuretic peptide biomarkers in HF patients with preserved and reduced ejection fraction.

Biomarkers, myocardial fibrosis and co-morbidities in heart failure with preserved ejection fraction: an overview

The prevalence of heart failure with preserved ejection fraction (HFpEF) is steadily increasing. Its diagnosis remains difficult and controversial and relies mostly on non-invasive echocardiographic detection of left ventricular diastolic dysfunction and elevated filling pressures. The large phenotypic heterogeneity of HFpEF from pathophysiologic al underpinnings to clinical manifestations presents a major obstacle to the development of new therapies targeted towards specific HF phenotypes. Recent studies suggest that natriuretic peptides have the potential to improve the diagnosis of early HFpEF, but they still have significant limitations, and the cut-off points for diagnosis and prognosis in HFpEF remain open to debate. The purpose of this review is to present potential targets of intervention in patients with HFpEF, starting with myocardial fibrosis and methods of its detection. In addition, co-morbidities are discussed as a means to treat HFpEF according to cut-points of biomarkers that are different from usual. Biomarkers and approaches to co-morbidities may be able to tailor therapies according to patients' pathophysiological needs. Recently, soluble source of tumorigenicity 2 (sST2), growth differentiation factor 15 (GDF-15), galectin-3, and other cardiac markers have emerged, but evidence from large cohorts is still lacking. Furthermore, the field of miRNA is a very promising area of research, and further exploration of miRNA may offer diagnostic and prognostic applications and insight into the pathology, pointing to new phenotype-specific therapeutic targets.

Mechanisms responsible for increased circulating levels of galectin-3 in cardiomyopathy and heart failure

Galectin-3 is a biomarker of heart disease. However, it remains unknown whether increase in galectin-3 levels is dependent on aetiology or disease-associated conditions and whether diseased heart releases galectin-3 into the circulation. We explored these questions in mouse models of heart disease and in patients with cardiomyopathy. All mouse models (dilated cardiomyopathy, DCM; fibrotic cardiomyopathy, ischemia-reperfusion, I/R; treatment with β-adrenergic agonist isoproterenol) showed multi-fold increases in cardiac galectin-3 expression and preserved renal function. In mice with fibrotic cardiomyopathy, I/R or isoproterenol treatment, plasma galectin-3 levels and density of cardiac inflammatory cells were elevated. These models also exhibited parallel changes in cardiac and plasma galectin-3 levels and presence of trans-cardiac galectin-3 gradient, indicating cardiac release of galectin-3. DCM mice showed no change in circulating galectin-3 levels nor trans-cardiac galectin-3 gradient or myocardial inflammatory infiltration despite a 50-fold increase in cardiac galectin-3 content. In patients with hypertrophic cardiomyopathy or DCM, plasma galectin-3 increased only in those with renal dysfunction and a trans-cardiac galectin-3 gradient was not present. Collectively, this study documents the aetiology-dependency and diverse mechanisms of increment in circulating galectin-3 levels. Our findings highlight cardiac inflammation and enhanced β-adrenoceptor activation in mediating elevated galectin-3 levels via cardiac release in the mechanism.

The effects of galectin-3 depletion apheresis on induced skin inflammation in a porcine model

Galectin-3 (Gal-3), a β-galactoside-binding lectin that is expressed in mammalian cells, is known to modulate several biological functions such as cell-cell adhesion, macrophage activation, angiogenesis, metastasis, and fibrosis. The goal of this study was to evaluate the ability of Gal-3 depletion apheresis using an adsorption column with immobilized anti-Gal-3-antibody to reduce inflammation induced by Complete Freund's Adjuvant injection in a skin inflammation porcine model. Here, we report that plasma perfusion by apheresis through a Gal-3 binding immuno-affinity column reduces plasma Gal-3 levels to below limits of quantitative detection, and results in significant decrease in skin inflammation, including degree and duration of inflammatory lesions. Human plasma was tested ex vivo and found to be efficiently depleted using the anti-Gal-3 affinity column. This study demonstrates the potential of Gal-3 depletion apheresis as a therapeutic method for inflammation-mediated disease, supporting continued research in this area for clinical application.

Is galectin-3 a promoter of ventricular dysfunction?

Heart failure is nowadays a common condition associated with high mortality and increased healthcare-related costs. Over the years, the research on heart failure management has been extensive in order to better diagnose and treat the condition. Since the progression of left ventricular dysfunction is a consequence of myocardial inflammation, apopotosis, and fibrosis leading to myocardium remodelling, several molecules that are involved in the inflammation pathways have been explored as possible biomarkers for the condition. The study of biomarkers and their key roles in inflammation could allow early identification of patients with heart failure, improve prognostic assessment, and provide a target for future therapies. Among currently studied biomarkers, extensive research has been conducted on galectin-3, a galactoside-binding lectin, which is synthetised and secreted when cardiomyocytes and fibroblasts are submitted to mechanical stress. Accordingly, it has been hypothesised that galectin-3 could be a promoter of left ventricular dysfunction. Galectin-3 has been shown to mediate inflammation by several different pathways which are further detailed in the current review. Also, we aimed to provide a comprehensive overview of existing evidence on the utility of galectin-3 in clinical settings associated with heart failure.

Galectin-3 levels relate in children to total body fat, abdominal fat, body fat distribution, and cardiac size

Galectin-3 has recently been proposed as a novel biomarker for cardiovascular disease in adults. The purpose of this investigation was to assess relationships between galectin-3 levels and total body fat, abdominal fat, body fat distribution, aerobic fitness, blood pressure, left ventricular mass, left atrial size, and increase in body fat over a 2-year period in a population-based sample of children. Our study included 170 children aged 8-11 years. Total fat mass and abdominal fat were measured by dual-energy x-ray absorptiometry (DXA). Body fat distribution was expressed as abdominal fat/total fat mass. Maximal oxygen uptake was assessed by indirect calorimetry during a maximal exercise test and scaled to body mass. Systolic and diastolic blood pressure and pulse pressure were measured. Left atrial size, left ventricular mass, and relative wall thickness were measured by echocardiography. Frozen serum samples were analyzed for galectin-3 by the Proximity Extension Assay technique. A follow-up DXA scan was performed in 152 children 2 years after the baseline exam. Partial correlations, with adjustment for sex and age, between galectin-3 versus body fat measurements indicated weak to moderate relationships. Moreover, left atrial size, left ventricular mass, and relative wall thickness and pulse pressure were also correlated with galectin-3. Neither systolic blood pressure nor maximal oxygen uptake was correlated with galectin-3. There was also a correlation between galectin-3 and increase in total body fat over 2 years, while no such correlations were found for the other fat measurements.

CONCLUSION

More body fat and abdominal fat, more abdominal body fat distribution, more left ventricular mass, and increased left atrial size were all associated with higher levels of galectin-3. Increase in total body fat over 2 years was also associated with higher levels of galectin-3. What is Known: • Galectin-3 has been linked to obesity and been proposed to be a novel biomarker for cardiovascular disease in adults. • Information on this subject in children is very scarce. What is New: • The present study demonstrates a relationship between galectin-3 levels and total body fat, abdominal fat, body fat distribution, cardiac size and geometry, and increase in total body fat over 2 years in young children.

Clinical Phenotyping of Heart Failure with Biomarkers: Current and Future Perspectives

INTRODUCTION

Heart failure (HF) is a complex clinical syndrome with diverse risk factors and etiologies, differing underlying pathophysiology, and large phenotypic heterogeneity.

RECENT FINDINGS

Advances in imaging techniques coupled with clinical trials that targeted only in those with impaired left ventricular ejection fraction (LVEF) have largely shaped the current management strategy for HF that focuses predominantly in patients with systolic HF. In contrast, there are no effective treatments for HF with preserved ejection fraction (HFpEF). Instead of this "one-size-fits-all" approach to treatment, better precision to define HF phenotypic classifications may lead to more efficient and effective HF disease management.

CONCLUSION

Integrating variables-including clinical variables, HF biomarkers, imaging, genotypes, metabolomics, and proteomics-can identify different pathophysiologies, lead to more precise phenotypic classification, and warrant investigation in future clinical trials.

Galectin-3 as a novel biomarker for disease diagnosis and a target for therapy (Review)

Galectin-3 is a member of the galectin family, which are β‑galactoside‑binding lectins with ≥1 evolutionary conserved carbohydrate‑recognition domain. It binds proteins in a carbohydrate‑dependent and ‑independent manner. Galectin‑3 is predominantly located in the cytoplasm; however, it shuttles into the nucleus and is secreted onto the cell surface and into biological fluids including serum and urine. It serves important functions in numerous biological activities including cell growth, apoptosis, pre‑mRNA splicing, differentiation, transformation, angiogenesis, inflammation, fibrosis and host defense. Numerous previous studies have indicated that galectin‑3 may be used as a diagnostic or prognostic biomarker for certain types of heart disease, kidney disease and cancer. With emerging evidence to support the function and application of galectin‑3, the current review aims to summarize the latest literature regarding the biomarker characteristics and potential therapeutic application of galectin‑3 in associated diseases.

Interleukin-1 blockade in heart failure with preserved ejection fraction: rationale and design of the Diastolic Heart Failure Anakinra Response Trial 2 (D-HART2)

Heart failure with preserved ejection fraction (HFpEF) now accounts for the majority of confirmed HF cases in the United States. However, there are no highly effective evidence-based treatments currently available for these patients. Inflammation correlates positively with adverse outcomes in HF patients. Interleukin (IL)-1, a prototypical inflammatory cytokine, has been implicated as a driver of diastolic dysfunction in preclinical animal models and a pilot clinical trial. The Diastolic Heart Failure Anakinra Response Trial 2 (D-HART2) is a phase 2, 2:1 randomized, double-blind, placebo-controlled clinical trial that will test the hypothesis that IL-1 blockade with anakinra (recombinant human IL-1 receptor antagonist) improves (1) cardiorespiratory fitness, (2) objective evidence of diastolic dysfunction, and (3) elevated inflammation in patients with HFpEF (http://www.ClinicalTrials.gov NCT02173548). The co-primary endpoints will be placebo-corrected interval changes in peak oxygen consumption and ventilatory efficiency at week 12. In addition, secondary and exploratory analyses will investigate the effects of IL-1 blockade on cardiac structure and function, systemic inflammation, endothelial function, quality of life, body composition, nutritional status, and clinical outcomes. The D-HART2 clinical trial will add to the growing body of evidence on the role of inflammation in cardiovascular disease, specifically focusing on patients with HFpEF.

Clinical Correlates and Prognostic Value of Plasma Galectin-3 Levels in Degenerative Aortic Stenosis: A Single-Center Prospective Study of Patients Referred for Invasive Treatment

Galectin-3 (Gal-3), a β-galactoside-binding lectin, has been implicated in myocardial fibrosis, development of left ventricular (LV) dysfunction and transition from compensated LV hypertrophy to overt heart failure (HF), being a novel prognostic marker in HF. Risk stratification is crucial for the choice of the optimal therapy in degenerative aortic stenosis (AS), affecting elderly subjects with coexistent diseases. Our aim was to assess correlates and prognostic value of circulating Gal-3 in real-world patients with degenerative AS referred for invasive treatment. Gal-3 levels were measured at admission in 80 consecutive patients with symptomatic degenerative AS (mean age: 79 ± 8 years; aortic valve area (AVA) index: 0.4 ± 0.1 cm²/m²). The therapeutic strategy was chosen following a dedicated multidisciplinary team-oriented approach, including surgical valve replacement (n = 11), transcatheter valve implantation (n = 19), balloon aortic valvuloplasty (BAV) (n = 25) and optimal medical therapy (n = 25). Besides routine echocardiographic indices, valvulo-arterial impedance (Zva), an index of global LV afterload, was computed. There were 22 deaths over a median follow-up of 523 days. Baseline Gal-3 correlated negatively with estimated glomerular filtration rate (eGFR) (r = -0.61, p < 0.001) and was unrelated to age, symptomatic status, AVA index, LV ejection fraction, LV mass index or Zva. For the study group as a whole, Gal-3 tended to predict mortality (Gal-3 >17.8 vs. Gal-3 <17.8 ng/mL; hazard ratio (HR): 2.03 (95% confidence interval, 0.88-4.69), p = 0.09), which was abolished upon adjustment for eGFR (HR: 1.70 (0.61-4.73), p = 0.3). However, in post-BAV patients multivariate-adjusted pre-procedural Gal-3 was associated with worse survival (HR: 7.41 (1.52-36.1), p = 0.01) regardless of eGFR. In conclusion, the inverse eGFR-Gal-3 relationship underlies a weak association between Gal-3 and adverse outcome in patients with degenerative AS referred for invasive therapy irrespective of type of treatment employed. In contrast, pre-procedural Gal-3 appears an independent mortality predictor in high-risk AS patients undergoing BAV.

Plasma and Cardiac Galectin-3 in Patients With Heart Failure Reflects Both Inflammation and Fibrosis

Background—

Galectin (Gal)-3 is a β-galactoside-binding lectin and currently intensely studied as a biomarker in heart failure. Gal-3 also exerts proinflammatory effects, at least in extracardiac tissues. Objective of this study was to characterize the relationship of plasma and myocardial Gal-3 levels with cardiac fibrosis and inflammation in patients with nonischemic dilated cardiomyopathy and inflammatory cardiomyopathy (iCMP).

Methods and Results—

Endomyocardial biopsies and blood samples were obtained from patients with newly diagnosed cardiomyopathy and clinical suspicion of myocarditis. According to histopathologic findings, patients were classified as having dilated cardiomyopathy (n=40) or iCMP (n=75). Cardiac fibrosis was assessed histologically on endomyocardial biopsy sections. In patients with iCMP, myocardial Gal-3 expression significantly correlated with inflammatory cell count on endomyocardial biopsy ( r =0.56; P <0.05). In contrast, an inverse association was observed between myocardial Gal-3 expression and cardiac fibrosis in patients with iCMP ( r =−0.59; P <0.05). In patients with dilated cardiomyopathy, myocardial Gal-3 expression correlated with cardiac fibrosis on left ventricular biopsy ( P =0.63; P <0.01). Of note, in both groups, plasma Gal-3 levels did not correlate with myocardial Gal-3 levels or left ventricular fibrosis, whereas a positive correlation between plasma Gal-3 levels and inflammatory cell count on endomyocardial biopsy was observed in patients with iCMP.

Conclusions—

The present study suggests that myocardial Gal-3 can be considered as a possible marker for both cardiac inflammation and fibrosis, depending on the pathogenesis of heart failure. However, circulating concentrations of Gal-3 do not seem to reflect endomyocardial Gal-3 levels or cardiac fibrosis.

New Management Strategies in Heart Failure

Despite >100 clinical trials, only 2 new drugs had been approved by the US Food and Drug Administration for the treatment of chronic heart failure in more than a decade: the aldosterone antagonist eplerenone in 2003 and a fixed dose combination of hydralazine-isosorbide dinitrate in 2005. In contrast, 2015 has witnessed the Food and Drug Administration approval of 2 new drugs, both for the treatment of chronic heart failure with reduced ejection fraction: ivabradine and another combination drug, sacubitril/valsartan or LCZ696. Seemingly overnight, a range of therapeutic possibilities, evoking new physiological mechanisms, promise great hope for a disease that often carries a prognosis worse than many forms of cancer. Importantly, the newly available therapies represent a culmination of basic and translational research that actually spans many decades. This review will summarize newer drugs currently being used in the treatment of heart failure, as well as newer strategies increasingly explored for their utility during the stages of the heart failure syndrome.

Plasma Biomarkers Reflecting Profibrotic Processes in Heart Failure With a Preserved Ejection Fraction: Data From the Prospective Comparison of ARNI With ARB on Management of Heart Failure With Preserved Ejection Fraction Study

BACKGROUND

Heart failure with preserved ejection fraction is a clinical syndrome that has been associated with changes in the extracellular matrix. The purpose of this study was to determine whether profibrotic biomarkers accurately reflect the presence and severity of disease and underlying pathophysiology and modify response to therapy in patients with heart failure with preserved ejection fraction.

METHODS AND RESULTS

Four biomarkers, soluble form of ST2 (an interleukin-1 receptor family member), galectin-3, matrix metalloproteinase-2, and collagen III N-terminal propeptide were measured in the Prospective Comparison of ARNI With ARB on Management of Heart Failure With Preserved Ejection Fraction (PARAMOUNT) trial at baseline, 12 and 36 weeks after randomization to valsartan or LCZ696. We examined the relationship between baseline biomarkers, demographic and echocardiographic characteristics, change in primary (change in N-terminal pro B-type natriuretic peptide) and secondary (change in left atrial volume) end points. The median (interquartile range) value for soluble form of ST2 (33 [24.6-48.1] ng/mL) and galectin 3 (17.8 [14.1-22.8] ng/mL) were higher, and for matrix metalloproteinase-2 (188 [155.5-230.6] ng/mL) lower, than in previously published referent controls; collagen III N-terminal propeptide (5.6 [4.3-6.9] ng/mL) was similar to referent control values. All 4 biomarkers correlated with severity of disease as indicated by N-terminal pro B-type natriuretic peptide, E/E', and left atrial volume. Baseline biomarkers did not modify the response to LCZ696 for lowering N-terminal pro B-type natriuretic peptide; however, left atrial volume reduction varied by baseline level of soluble form of ST2 and galectin 3; patients with values less than the observed median (<33 ng/mL soluble form of ST2 and <17.8 ng/mL galectin 3) had reduction in left atrial volume, those above median did not. Although LCZ696 reduced N-terminal pro B-type natriuretic peptide, levels of the other 4 biomarkers were not affected over time.

CONCLUSIONS

In patients with heart failure with preserved ejection fraction, biomarkers that reflect collagen homeostasis correlated with the presence and severity of disease and underlying pathophysiology, and may modify the structural response to treatment.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00887588.

Aging and the cardiac collagen matrix: Novel mediators of fibrotic remodelling

Cardiovascular disease is a leading cause of death worldwide and there is a pressing need for new therapeutic strategies to treat such conditions. The risk of developing cardiovascular disease increases dramatically with age, yet the majority of experimental research is executed using young animals. The cardiac extracellular matrix (ECM), consisting predominantly of fibrillar collagen, preserves myocardial integrity, provides a means of force transmission and supports myocyte geometry. Disruptions to the finely balanced control of collagen synthesis, post-synthetic deposition, post-translational modification and degradation may have detrimental effects on myocardial functionality. It is now well established that the aged heart is characterized by fibrotic remodelling, but the mechanisms responsible for this are incompletely understood. Furthermore, studies using aged animal models suggest that interstitial remodelling with disease may be age-dependent. Thus with the identification of new therapeutic strategies targeting fibrotic remodelling, it may be necessary to consider age-dependent mechanisms. In this review, we discuss remodelling of the cardiac collagen matrix as a function of age, whilst highlighting potential novel mediators of age-dependent fibrotic pathways.

The role of titin and extracellular matrix remodelling in heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is characterised by a high incidence of metabolic comorbidities that share the potential to induce both systemic and coronary microvascular inflammation and oxidative stress. These pathophysiological alterations contribute to increased passive stiffness of the myocardium and to diastolic dysfunction, both hallmarks of HFpEF. Passive myocardial stiffness depends mainly on two components: the extracellular matrix (ECM) and the cardiomyocytes. Quantitative and qualitative changes in collagen metabolism leading to myocardial fibrosis determine the ECM-based stiffness of the myocardium. Different noninvasive diagnostic tools to assess myocardial fibrosis are being developed, some of which have demonstrated to correlate with clinical status and prognosis. Cardiomyocytes mainly alter the passive stiffness through alterations in the giant myofilament titin, which serves as a spring. By modifying its phosphorylation state or by direct oxidative effects, titin determines cardiomyocyte-based passive stiffness. Probably the relative importance of cardiomyocyte-based changes is more important in the beginning of the disease, whereas ECM-based changes become more prominent in the more advanced stages. The present review focuses on these changes in ECM and cardiomyocytes in HFpEF and their potential prognostic and therapeutic implications.

Biomarkers in heart failure with preserved ejection fraction

Biomarkers are widely used and studied in heart failure. Most studies have described the utility and performance of biomarkers in sub-studies of randomised clinical trials, where the vast majority of the patients suffered from heart failure with reduced ejection fraction (HFrEF), and not with preserved ejection fraction (HFpEF). As a result, there is a scarcity of data describing the levels, dynamics, clinical and biochemical correlates, and biology of biomarkers in patients suffering from HFpEF, whereas HFpEF is in fact a very frequent clinical entity. This article discusses the value of different biomarkers in HFpEF. We describe various aspects of natriuretic peptide measurements in HFpEF patients, with a focus on diagnosis, prognosis and the risk prediction of developing heart failure. Further, we will discuss several emerging biomarkers such as galectin-3 and suppression of tumorigenicity 2, and recently discovered ones such as growth differentiation factor-15 and syndecan-1.

Vascular Fibrosis in Aging and Hypertension: Molecular Mechanisms and Clinical Implications

Aging is the primary risk factor underlying hypertension and incident cardiovascular disease. With aging, the vasculature undergoes structural and functional changes characterized by endothelial dysfunction, wall thickening, reduced distensibility, and arterial stiffening. Vascular stiffness results from fibrosis and extracellular matrix (ECM) remodelling, processes that are associated with aging and are amplified by hypertension. Some recently characterized molecular mechanisms underlying these processes include increased expression and activation of matrix metalloproteinases, activation of transforming growth factor-β1/SMAD signalling, upregulation of galectin-3, and activation of proinflammatory and profibrotic signalling pathways. These events can be induced by vasoactive agents, such as angiotensin II, endothelin-1, and aldosterone, which are increased in the vasculature during aging and hypertension. Complex interplay between the “aging process” and prohypertensive factors results in accelerated vascular remodelling and fibrosis and increased arterial stiffness, which is typically observed in hypertension. Because the vascular phenotype in a young hypertensive individual resembles that of an elderly otherwise healthy individual, the notion of “early” or “premature” vascular aging is now often used to describe hypertension-associated vascular disease. We review the vascular phenotype in aging and hypertension, focusing on arterial stiffness and vascular remodelling. We also highlight the clinical implications of these processes and discuss some novel molecular mechanisms of fibrosis and ECM reorganization.

Connecting heart failure with preserved ejection fraction and renal dysfunction: the role of endothelial dysfunction and inflammation

Renal dysfunction in heart failure with preserved ejection fraction (HFpEF) is common and is associated with increased mortality. Impaired renal function is also a risk factor for developing HFpEF. A new paradigm for HFpEF, proposing a sequence of events leading to myocardial remodelling and dysfunction in HFpEF, was recently introduced, involving inflammatory, microvascular, and cardiac components. The kidney might play a key role in this systemic process. Renal impairment causes metabolic and systemic derangements in circulating factors, causing an activated systemic inflammatory state and endothelial dysfunction, which may lead to cardiomyocyte stiffening, hypertrophy, and interstitial fibrosis via cross-talk between the endothelium and cardiomyocyte compartments. Here, we review the role of endothelial dysfunction and inflammation to explain the link between renal dysfunction and HFpEF, which allows for identification of new early risk markers, prognostic factors, and unique targets for intervention.

Role of biomarkers in cardiac structure phenotyping in heart failure with preserved ejection fraction: critical appraisal and practical use

Heart failure (HF) with preserved ejection fraction (HFpEF) is a heterogeneous clinical syndrome characterized by cardiovascular, metabolic, and pro-inflammatory diseases associated with advanced age and extracardiac comorbidities. All of these conditions finally lead to impairment of myocardial structure and function. The large phenotypic heterogeneity of HFpEF from pathophysiological underpinnings presents a major hurdle to HFpEF therapy. The new therapeutic approach in HFpEF should be targeted to each HF phenotype, instead of the 'one-size-fits-all' approach, which has not been successful in clinical trials. Unless the structural and biological determinants of the failing heart are deeply understood, it will be impossible to appropriately differentiate HFpEF patients, identify subtle myocardial abnormalities, and finally reverse abnormal cardiac function. Based on evidence from endomyocardial biopsies, some of the specific cardiac structural phenotypes to be targeted in HFpEF may be represented by myocyte hypertrophy, interstitial fibrosis, myocardial inflammation associated with oxidative stress, and coronary disease. Once the diagnosis of HFpEF has been established, a potential approach could be to use a panel of biomarkers to identify the main cardiac structural HFpEF phenotypes, guiding towards more appropriate therapeutic strategies. Accordingly, the purpose of this review is to investigate the potential role of biomarkers in identifying different cardiac structural HFpEF phenotypes and to discuss the merits of a biomarker-guided strategy in HFpEF.

Association Between Use of Statins and Mortality in Patients With Heart Failure and Ejection Fraction of ≥50%

Background—

The pathophysiology of heart failure with preserved ejection fraction is poorly understood, but may involve a systemic proinflammatory state. Therefore, statins might improve outcomes in patients with heart failure with preserved ejection fraction defined as ≥50%.

Methods and Results—

Of 46 959 unique patients in the prospective Swedish Heart Failure Registry, 9140 patients had heart failure and ejection fraction ≥50% (age 77±11 years, 54.0% women), and of these, 3427 (37.5%) were treated with statins. Propensity scores for statin treatment were derived from 40 baseline variables. The association between statin use and primary (all-cause mortality) and secondary (separately, cardiovascular mortality, and combined all-cause mortality or cardiovascular hospitalization) end points was assessed with Cox regressions in a population matched 1:1 based on age and propensity score. In the matched population, 1-year survival was 85.1% for statin-treated versus 80.9% for untreated patients (hazard ratio, 0.80; 95% confidence interval, 0.72–0.89; P <0.001). Statins were also associated with reduced cardiovascular death (hazard ratio, 0.86; 95% confidence interval, 0.75–0.98; P =0.026) and composite all-cause mortality or cardiovascular hospitalization (hazard ratio, 0.89; 95% confidence interval, 0.82–0.96; P =0.003).

Conclusions—

In heart failure with ejection fraction ≥50%, the use of statins was associated with improved outcomes. The mechanisms should be evaluated and the effects tested in a randomized trial.