Biomarkers to Predict Reverse Remodeling and Myocardial Recovery in Heart Failure

Mono- and Bi-specific Nanobodies Targeting the CUB Domains of PCPE-1 Reduce the Proteolytic Processing of Fibrillar Procollagens

The excessive deposition of fibrillar collagens is a hallmark of fibrosis. Collagen fibril formation requires proteolytic maturations by Procollagen N- and C-proteinases (PNPs and PCPs) to remove the N- and C-propeptides which maintain procollagens in the soluble form. Procollagen C-Proteinase Enhancer-1 (PCPE-1, a glycoprotein composed of two CUB domains and one NTR domain) is a regulatory protein that activates the C-terminal processing of procollagens by the main PCPs. It is often up-regulated in fibrotic diseases and represents a promising target for the development of novel anti-fibrotic strategies. Here, our objective was to develop the first antagonists of PCPE-1, based on the nanobody scaffold. Using both an in vivo selection through the immunization of a llama and an in vitro selection with a synthetic library, we generated 18 nanobodies directed against the CUB domains of PCPE1, which carry its enhancing activity. Among them, I5 from the immune library and H4 from the synthetic library have a high affinity for PCPE-1 and inhibit its interaction with procollagens. The crystal structure of the complex formed by PCPE-1, H4 and I5 showed that they have distinct epitopes and enabled the design of a biparatopic fusion, the diabody diab-D1. Diab-D1 has a sub-nanomolar affinity for PCPE-1 and is a potent antagonist of its activity, preventing the stimulation of procollagen cleavage in vitro. Moreover, Diab-D1 is also effective in reducing the proteolytic maturation of procollagen I in cultures of human dermal fibroblasts and hence holds great promise as a tool to modulate collagen deposition in fibrotic conditions.

Myocardial Recovery and Relapse in Heart Failure With Improved Ejection Fraction

Purpose of review

The purpose of this review is to discuss myocardial recovery in heart failure with reduced ejection fraction (HFrEF) and to summarize the contemporary insights regarding heart failure with improved ejection fraction (HFimpEF).

Recent findings

Improvement in left ventricular ejection fraction (LVEF ≥ 40%) with improved prognosis can be achieved in one out of three (10-40%) patients with HFrEF treated with guideline-directed medical therapy. Clinical predictors include non-ischemic etiology of HFrEF, less abnormal blood or imaging biomarkers, and lack of specific pathogenic genetic variants. However, a subset of patients may ultimately relapse, suggesting that many patients are merely in remission rather than having fully recovered.

Summary

Patients with HFimpEF have improved prognosis but nonetheless remain at risk of relapse and long-term adverse events. Future studies will hopefully chart the natural history of HFimpEF and identify clinical predictors such as blood or novel imaging biomarkers that distinguish subgroups of patients based on differential trajectory and prognosis.

Myocardial Recovery

In this paper, the feasibility of myocardial recovery is analyzed through a literature review. First, the phenomena of remodeling and reverse remodeling are analyzed, approached through the physics of elastic bodies, and the terms myocardial depression and myocardial recovery are defined. Continuing, potential biochemical, molecular, and imaging markers of myocardial recovery are reviewed. Then, the work focuses on therapeutic techniques that can facilitate the reverse remodeling of the myocardium. Left ventricular assist device (LVAD) systems are one of the main ways to promote cardiac recovery. The changes that take place in cardiac hypertrophy, extracellular matrix, cell populations and their structural elements, β-receptors, energetics, and several biological processes, are reviewed. The attempt to wean the patients who experienced cardiac recovery from cardiac assist device systems is also discussed. The characteristics of the patients who will benefit from LVAD are presented and the heterogeneity of the studies performed in terms of patient populations included, diagnostic tests performed, and their results are addressed. The experience with cardiac resynchronization therapy (CRT) as another way to promote reverse remodeling is also reviewed. Myocardial recovery is a phenomenon that presents with a continuous spectrum of phenotypes. There is a need for algorithms to screen suitable patients who may benefit and identify specific ways to enhance this phenomenon in order to help combat the heart failure epidemic.

A review of biomarker and imaging monitoring to predict heart failure recovery

Heart failure is a clinical syndrome caused by structural cardiac abnormalities that lead to increased intracardiac pressures and decreased cardiac output. Following cardiovascular insult or direct myocardial injury, neurohormonal activation triggers hemodynamic changes and cardiac remodeling to preserve cardiac output. While initially adaptive, cardiac remodeling eventually causes pathologic changes in cardiac structure that often compromise cardiac function. Reverse remodeling is the regression of abnormal cardiac chamber geometry and function after myocardial injury. In recent years, several classes of therapeutics have been associated with greater likelihood of reverse remodeling. Heart failure recovery and heart failure remission, terms encompassing the clinical correlates of reverse remodeling, have been associated with improved survival in patients with heart failure with reduced ejection. As such, identifying predictors of heart failure recovery can have important implications for guiding clinical practice and therapeutic innovation. This review addresses the role of biomarkers and imaging monitoring in predicting structural, functional, and clinical recovery in patients with acute and chronic heart failure.

Prediction of Left Ventricular Reverse Remodeling and Outcomes by Circulating Collagen-Derived Peptides

BACKGROUND

Myocardial fibrosis may increase vulnerability to poor prognosis in patients with heart failure (HF), even in those patients exhibiting left ventricular reverse remodeling (LVRR) after guideline-based therapies.

OBJECTIVES

This study sought to characterize fibrosis at baseline in patients with HF with left ventricular ejection fraction (LVEF) <50% by determining serum collagen type I-derived peptides (procollagen type I C-terminal propeptide [PICP] and ratio of collagen type I C-terminal telopeptide to matrix metalloproteinase-1) and to evaluate their association with LVRR and prognosis.

METHODS

Peptides were determined in 1,034 patients with HF at baseline. One-year echocardiography was available in 665 patients. Associations of peptides with 1-year changes in echocardiographic variables were analyzed by multivariable linear mixed models. LVEF was considered improved if it increased by ≥15% or to ≥50% or if it increased by ≥10% to >40% in patients with LVEF ≤40%. Cardiovascular death and HF-related outcomes were analyzed in all patients randomized to derivation (n = 648) and validation (n = 386) cohorts.

RESULTS

Continuous associations with echocardiographic changes were observed only for PICP. Compared with high-PICP (≥108.1 ng/mL) patients, low-PICP (<108.1 ng/mL) patients exhibited enhanced LVRR and a lower risk of HF-related outcomes (P ≤ 0.018), with women and nonischemic patients with HF showing a stronger LVEF increase (interaction P ≤ 0.010). LVEF increase was associated with a better prognosis, particularly in low-PICP patients (interaction P ≤ 0.029). Only patients with both low PICP and improved LVEF exhibited a better clinical evolution than patients with nonimproved LVEF (P < 0.001).

CONCLUSIONS

Phenotyping with PICP, a peptide associated with myocardial fibrosis, may be useful to differentiate patients with HF who are more likely to experience clinical myocardial recovery from those with partial myocardial improvement.

Pediatric and adult dilated cardiomyopathy are distinguished by distinct biomarker profiles

BACKGROUND

Emerging evidence suggests that pediatric and adult dilated cardiomyopathy (DCM) represent distinct diseases. Few diagnostic tools exist for pediatric cardiologists to assess clinical status and prognosis. We hypothesized that pediatric DCM would have a unique biomarker profile compared to adult DCM and controls.

METHODS

We utilized a DNA aptamer array (SOMAScan) to compare biomarker profiles between pediatric and adult DCM. We simultaneously measured 1310 plasma proteins and peptides from 39 healthy children (mean age 3 years, interquartile range (IQR) 1-14), 39 ambulatory subjects with pediatric DCM (mean age 2.7 years, IQR 1-13), and 40 ambulatory adults with DCM (mean age 53 years, IQR 46-63).

RESULTS

Pediatric and adult DCM patients displayed distinct biomarker profiles, despite similar clinical characteristics. We identified 20 plasma peptides and proteins that were increased in pediatric DCM compared to age- and sex-matched controls. Unbiased multidimensionality reduction analysis suggested previously unrecognized heterogeneity among pediatric DCM subjects. Biomarker profile analysis identified four subgroups of pediatric DCM with distinguishing clinical characteristics.

CONCLUSIONS

These findings support the emerging concept that pediatric and adult DCM are distinct disease entities, signify the need to develop pediatric-specific biomarkers for disease prognostication, and challenge the paradigm that pediatric DCM should be viewed as a single disease.

IMPACT

Pediatric and adult DCM patients displayed distinct biomarker profiles, despite similar clinical characteristics and outcomes. Our findings suggest that pediatric DCM may be a heterogeneous disease with various sub-phenotypes, including differing biomarker profiles and clinical findings. These data provide prerequisite information for future prospective studies that validate the identified pediatric DCM biomarkers, address their diagnostic accuracy and prognostic significance, and explore the full extent of heterogeneity amongst pediatric DCM patients.

Cardiac remodelling - Part 1: From cells and tissues to circulating biomarkers. A review from the Study Group on Biomarkers of the Heart Failure Association of the European Society of Cardiology

Cardiac remodelling refers to changes in left ventricular structure and function over time, with a progressive deterioration that may lead to heart failure (HF) development (adverse remodelling) or vice versa a recovery (reverse remodelling) in response to HF treatment. Adverse remodelling predicts a worse outcome, whilst reverse remodelling predicts a better prognosis. The geometry, systolic and diastolic function and electric activity of the left ventricle are affected, as well as the left atrium and on the long term even right heart chambers. At a cellular and molecular level, remodelling involves all components of cardiac tissue: cardiomyocytes, fibroblasts, endothelial cells and leucocytes. The molecular, cellular and histological signatures of remodelling may differ according to the cause and severity of cardiac damage, and clearly to the global trend toward worsening or recovery. These processes cannot be routinely evaluated through endomyocardial biopsies, but may be reflected by circulating levels of several biomarkers. Different classes of biomarkers (e.g. proteins, non-coding RNAs, metabolites and/or epigenetic modifications) and several biomarkers of each class might inform on some aspects on HF development, progression and long-term outcomes, but most have failed to enter clinical practice. This may be due to the biological complexity of remodelling, so that no single biomarker could provide great insight on remodelling when assessed alone. Another possible reason is a still incomplete understanding of the role of biomarkers in the pathophysiology of cardiac remodelling. Such role will be investigated in the first part of this review paper on biomarkers of cardiac remodelling.

Procollagen C-proteinase enhancer-1 (PCPE-1), a potential biomarker and therapeutic target for fibrosis

The correct balance between collagen synthesis and degradation is essential for almost every aspect of life, from development to healthy aging, reproduction and wound healing. When this balance is compromised by external or internal stress signals, it very often leads to disease as is the case in fibrotic conditions. Fibrosis occurs in the context of defective tissue repair and is characterized by the excessive, aberrant and debilitating deposition of fibril-forming collagens. Therefore, the numerous proteins involved in the biosynthesis of fibrillar collagens represent a potential and still underexploited source of therapeutic targets to prevent fibrosis. One such target is procollagen C-proteinase enhancer-1 (PCPE-1) which has the unique ability to accelerate procollagen maturation by BMP-1/tolloid-like proteinases (BTPs) and contributes to trigger collagen fibrillogenesis, without interfering with other BTP functions or the activities of other extracellular metalloproteinases. This role is achieved through a fine-tuned mechanism of action that is close to being elucidated and offers promising perspectives for drug design. Finally, the in vivo data accumulated in recent years also confirm that PCPE-1 overexpression is a general feature and early marker of fibrosis. In this review, we describe the results which presently support the driving role of PCPE-1 in fibrosis and discuss the questions that remain to be solved to validate its use as a biomarker or therapeutic target.

The association between levels of serum homocysteine and chronic heart failure: A protocol for systematic review and meta-analysis

BACKGROUND

Homocysteine (Hcy) is one of the main factors leading to arteriosclerosis, which is closely related to cardiovascular disease. Recent studies have found that serum Hcy levels are increased in patients with chronic heart failure (CHF), and it is speculated that Hcy may be a risk factor for CHF, but evidence-based medicine evidence is lacking. The aim of this study was to investigate the correlation between serum Hcy levels and CHF by means of systematic review.

METHODS

The databases of PubMed, Embase, The Cochrance Library, Web of Science, CNKI (China National Knowledge Infrastructure), VIP (China Science and Technology Journal Database), Wanfang and China Biology Medicine disc were searched by computer. In addition, Baidu Scholar and Google Scholar were manually searched to collect all case-control studies related to serum Hcy and CHF. The search time limit was from database establishment to November 2020. Two reviewers independently screened the literatures, extracted the data and evaluated the risk of bias of the included literatures.

RESULTS

In this study, we evaluated the correlation between serum Hcy levels and CHF by the levels of serum Hcy in CHF patients and non-CHF patients.

CONCLUSIONS

This study will provide reliable evidence for the clinical value of serum Hcy in the field of CHF disease.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/QMPRC.

Cardiac magnetic resonance-derived fibrosis, strain and molecular biomarkers of fibrosis in hypertensive heart disease

AIMS

Myocardial fibrosis is a relevant component of hypertensive heart disease (HHD). Novel cardiovascular magnetic resonance (CMR) imaging techniques have shown potential in quantification of diffuse cardiac fibrosis, with T1 mapping, and estimating preclinical cardiac dysfunction, with strain analysis. Molecular biomarkers of fibrosis have been related with clinical outcomes and histologically proven myocardial fibrosis. The relationship between these CMR-imaging techniques and circulating biomarkers is not fully understood.

METHODS AND RESULTS

CMR was performed on a 3T scanner in 36 individuals with HHD. Extracellular volume fraction (ECV) and the partition coefficient were assessed using the T1 mapping technique shMOLLI. Longitudinal, circumferential and radial strain was assessed using CMR-Feature Tracking. Molecular biomarkers of collagen synthesis (PICP and PIIINP) and collagen degradation (CITP and MMP-1) were measured in blood using commercial kits. Correlation models showed a significant relationship of T1 mapping measures with left atrial diameter, LV mass, LV posterior wall thickness, LV end-diastolic volume and longitudinal strain. In fully adjusted regression models, ECV was associated with left atrial diameter (β=0.75, P = 0.005) and longitudinal strain (β = 0.43, P = 0.030); the partition coefficient was associated with LV posterior wall thickness (β = 0.53, P = 0.046). Strain measures were associated with cardiac geometry, and longitudinal strain was marginally associated with CITP.

CONCLUSION

In individuals with HHD, CMR-derived measures of myocardial fibrosis and function are related and might be useful tools for the identification and characterization of preclinical cardiac dysfunction and diffuse myocardial fibrosis. Molecular biomarkers of fibrosis were marginally associated with myocardial strain, but not with the extension of CMR-measured cardiac fibrosis.

Systolic function recovery in Heart Failure: Frequency, prognostic impact and predictors

BACKGROUND

Systolic function recovery in patients with Heart failure (HF) with reduced ejection fraction (EF) is well recognized but not completely understood. We aimed to characterize HF patients with systolic function recovery, its prognostic impact and predictors.

METHODS

We analysed patients followed in a HF clinic (2006-2015) with 2 echocardiograms performed. Partial recovery: EF recovery without attaining EF ≥ 50%; total recovery: patients reached EF ≥ 50%. Median follow-up from first echocardiogram: 69 months. Multivariate logistic regression models to determine recovery predictors.

RESULTS

We analysed 304 patients with at least mild left ventricular dysfunction. During a median 34 months between echocardiogram re-evaluation 150 (49.3%) patients showed no EF recovery; 55 (18.1%) had partial recovery and 99 (32.6%) totally recovered. Mean patients age: 66; 71.1% men, high comorbidity burden; ischemic HF: 35.5%. Non-recovered patients were mostly men (80.7% vs 61.8% in partially; 61.6% in fully-recovered) with ischemic HF (46.0% vs 32.5% in partially; 21.2% in fully-recovered). Comorbidity burden, NYHA class and therapy were similar. During follow-up, 156 patients (46.7%) died. Patients with total recovery had a multivariate-adjusted 54% lower risk of dying when compared to non-recovered. Partially-recovered patients showed a non-significant adjusted 8% mortality reduction. Independent predictors of systolic function recovery were female gender(OR: 2.17, 95% CI 1.11-4.35), non-ischemic aetiology (OR: 2.78, 95% CI 1.35-5.56), and end diastolic left ventricular diameter < 60 mm (OR: 3.12, 95% CI 1.56-6.25).

CONCLUSIONS

HF-recovered patients were mainly women with non-ischemic HF and smaller left ventricles. These patients had significantly better prognosis than those with persistently reduced EF.

Surgical and physiological challenges in the development of left and right heart failure in rat models

Rodent surgical animal models of heart failure (HF) are critically important for understanding the proof of principle of the cellular alterations underlying the development of the disease as well as evaluating therapeutics. Robust, reproducible rodent models are a prerequisite to the development of pharmacological and molecular strategies for the treatment of HF in patients. Due to the absence of standardized guidelines regarding surgical technique and clear criteria for HF progression in rats, objectivity is compromised. Scientific publications in rats rarely fully disclose the actual surgical details, and technical and physiological challenges. This lack of reporting is one of the main reasons that the outcomes specified in similar studies are highly variable and associated with unnecessary loss of animals, compromising scientific assessment. This review details rat circulatory and coronary arteries anatomy, the surgical details of rat models that recreate the HF phenotype of myocardial infarction, ischemia/reperfusion, left and right ventricular pressure, and volume overload states, and summarizes the technical and physiological challenges of creating HF. The purpose of this article is to help investigators understand the underlying issues of current HF models in order to reduce variable results and ensure successful, reproducible models of HF.

The Potential of Clinical Phenotyping of Heart Failure With Imaging Biomarkers for Guiding Therapies: A Focused Update

The need for noninvasive assessment of cardiac volumes and ejection fraction (EF) ushered in the use of cardiac imaging techniques in heart failure (HF) trials that investigated the roles of pharmacological and device-based therapies. However, in contrast to HF with reduced EF (HFrEF), modern HF pharmacotherapy has not improved outcomes in HF with preserved EF (HFpEF), largely attributed to patient heterogeneity and incomplete understanding of pathophysiological insights underlying the clinical presentations of HFpEF. Modern cardiac imaging methods offer insights into many sets of changes in cardiac tissue structure and function that can precisely link cause with cardiac remodeling at organ and tissue levels to clinical presentations in HF. This has inspired investigators to seek a more comprehensive understanding of HF presentations using imaging techniques. This article summarizes the available evidence regarding the role of cardiac imaging in HF. Furthermore, we discuss the value of cardiac imaging techniques in identifying HF patient subtypes who share similar causes and mechanistic pathways that can be targeted using specific HF therapies.

Paeoniflorin improves cardiac function and decreases adverse postinfarction left ventricular remodeling in a rat model of acute myocardial infarction

Background

Paeoniflorin (PF) is the active component of Paeonia lactiflora Pall. or Paeonia veitchii Lynch. This study was, therefore, aimed to evaluate the improvement and mechanism of the PF on ventricular remodeling in rats with acute myocardial infarction (AMI).

Materials and methods

In this study, AMI model was established by ligating the anterior descending coronary artery in Wistar rats. After 4 weeks gavage of PF, the apparent signs and the left ventricle weight index of Wistar rats were observed. The left ventricular ejection fraction (LVEF) was evaluated by Doppler ultrasonography. Changes in cardiac morphology were observed by pathologic examination, and apoptosis was observed by the terminal deoxynucleotidyl transferase dUTP nick end labeling assay. In addition, enzyme-linked immunosorbent assay was used to detect the expression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) interleukin-10 (IL-10) and brain natriuretic peptide (BNP). Immunohistochemistry and Western blot method were applied to detect Caspase-3 and Caspase-9.

Results

Compared with the model control, the survival conditions of rats in all treatment groups were generally improved after PF treatment. LVEF was significantly increased, and both left ventricular end-diastolic inner diameter and left ventricular end-systolic inner diameter were significantly reduced. Moreover, pathologic examination showed that the myocardium degeneration of the rats treated with PF was decreased, including neater arrangement, more complete myofilament, more uniform gap and less interstitial collagen fibers. Furthermore, the mitochondrial structure of cardiomyocytes was significantly improved. The ultrastructure was clear, and the arrangement of myofilament was more regular. Also, the expression of Caspase-3 and Caspase-9 was inhibited, and apoptosis was obviously reduced in the PF treatment groups. BNP, TNF-α and IL-6 were also decreased and IL-10 was increased in the treated rats.

Conclusion

PF could significantly improve the LVEF of rats. It decreased adverse left ventricular remodeling after myocardial infarction in rat models. The potential mechanism could be that PF decreased and inhibited BNP, TNF-α and IL-6, increased IL-10 and further inhibited the expression of Caspase-3 and Caspase-9, thus promoting ventricular remodeling.

The Interleukin-33/ST2 Pathway Is Expressed in the Failing Human Heart and Associated with Pro-fibrotic Remodeling of the Myocardium

The interleukin-33 (IL-33)/suppression of tumorigenicity 2 (ST2) pathway is a potential pathophysiological mediator of cardiac fibrosis. Soluble ST2 (sST2) is one of the main isoforms of ST2 with strong prognostic value in cardiac disease. The exact role of sST2 in cardiac fibrosis is unknown. The aim of this study was (1) to investigate myocardial expression of the IL-33/ST2 pathway in relation to myocardial fibrosis in end-stage heart failure patients and (2) to study whether plasma sST2 is associated with histologically determined cardiac fibrosis. In 38 patients undergoing left ventricular assist device implantation, mRNA expression of sST2, total ST2, and IL-33 was measured in cardiac tissue obtained during the implantation. In the same tissue, histological fibrosis was digitally quantified and mRNA expression of pro-fibrotic signaling molecules, connective tissue growth factor (CTGF) and transforming growth factor beta 1 (TGFβ1), was measured. In addition, plasma levels of sST2 were determined. Expression levels of IL-33/ST2 pathway factors in myocardial tissue were significantly associated with cardiac fibrosis and the expression levels of CTGF and TGFβ1. Plasma levels of sST2 did not correlate with tissue expression of ST2, the amount of fibrosis or myocardial expression of pro-fibrotic signaling proteins. The interleukin-33/ST2 pathway is expressed in the failing human heart and its expression is associated with cardiac fibrosis and pro-fibrotic signaling proteins, suggesting a role in pro-fibrotic myocardial remodeling. Soluble ST2 levels in the circulation did not correlate with the amount of cardiac fibrosis or myocardial ST2 expression, however. Therefore, other pathophysiological processes such as inflammation might also substantially affect sST2 plasma levels.