Rationale of the FIBROTARGETS study designed to identify novel biomarkers of myocardial fibrosis

Cardiac and Renal Fibrosis, the Silent Killer in the Cardiovascular Continuum: An Up-to-Date

Cardiovascular disease (CVD) and chronic kidney disease (CKD) often coexist and have a major impact on patient prognosis. Organ fibrosis plays a significant role in the pathogenesis of cardio-renal syndrome (CRS), explaining the high incidence of heart failure and sudden cardiac death in these patients. Various mediators and mechanisms have been proposed as contributors to the alteration of fibroblasts and collagen turnover, varying from hemodynamic changes to the activation of the renin-angiotensin system, involvement of FGF 23, and Klotho protein or collagen deposition. A better understanding of all the mechanisms involved has prompted the search for alternative therapeutic targets, such as novel inhibitors of the renin-angiotensin-aldosterone system (RAAS), serelaxin, and neutralizing interleukin-11 (IL-11) antibodies. This review focuses on the molecular mechanisms of cardiac and renal fibrosis in the CKD and heart failure (HF) population and highlights the therapeutic alternatives designed to target the responsible pathways.

Inductive database to support iterative data mining: Application to biomarker analysis on patient data in the Fight-HF project

Machine learning is now an essential part of any biomedical study but its integration into real effective Learning Health Systems, including the whole process of Knowledge Discovery from Data (KDD), is not yet realised. We propose an original extension of the KDD process model that involves an inductive database. We designed for the first time a generic model of Inductive Clinical DataBase (ICDB) aimed at hosting both patient data and learned models. We report experiments conducted on patient data in the frame of a project dedicated to fight heart failure. The results show how the ICDB approach allows to identify biomarker combinations, specific and predictive of heart fibrosis phenotype, that put forward hypotheses relative to underlying mechanisms. Two main scenarios were considered, a local-to-global KDD scenario and a trans-cohort alignment scenario. This promising proof of concept enables us to draw the contours of a next-generation Knowledge Discovery Environment (KDE).

The Interplay of Mitochondrial Oxidative Stress and Endoplasmic Reticulum Stress in Cardiovascular Fibrosis in Obese Rats

We have evaluated the role of mitochondrial oxidative stress and its association with endoplasmic reticulum (ER) stress activation in the progression of obesity-related cardiovascular fibrosis. MitoQ (200 µM) was orally administered for 7 weeks to male Wistar rats that were fed a high-fat diet (HFD, 35% fat) or a control diet (CT, 3.5% fat). Obese animals presented cardiovascular fibrosis accompanied by increased levels of extracellular matrix proteins and profibrotic mediators. These alterations were associated with ER stress activation characterized by enhanced levels (in heart and aorta vs. CT group, respectively) of immunoglobulin binding protein (BiP; 2.1-and 2.6-fold, respectively), protein disulfide-isomerase A6 (PDIA6; 1.9-fold) and CCAAT-enhancer-binding homologous protein (CHOP; 1.5- and 1.8-fold, respectively). MitoQ treatment was able to prevent (p < 0.05) these modifications at cardiac and aortic levels. MitoQ (5 nM) and the ER stress inhibitor, 4-phenyl butyric acid (4 µM), were able to block the prooxidant and profibrotic effects of angiotensin II (Ang II, 10⁻⁶ M) in cardiac and vascular cells. Therefore, the data show a crosstalk between mitochondrial oxidative stress and ER stress activation, which mediates the development of cardiovascular fibrosis in the context of obesity and in which Ang II can play a relevant role.

Network model-based screen for FDA-approved drugs affecting cardiac fibrosis

Cardiac fibrosis is a significant component of pathological heart remodeling, yet it is not directly targeted by existing drugs. Systems pharmacology approaches have the potential to provide mechanistic frameworks with which to predict and understand how drugs modulate biological systems. Here, we combine network modeling of the fibroblast signaling network with 36 unique drug-target interactions from DrugBank to predict drugs that modulate fibroblast phenotype and fibrosis. Galunisertib was predicted to decrease collagen and α-SMA expression, which we validated in human cardiac fibroblasts. In vivo fibrosis data from the literature validated predictions for 10 drugs. Further, the model was used to identify network mechanisms by which these drugs work. Arsenic trioxide was predicted to induce fibrosis by AP1-driven TGFβ expression and MMP2-driven TGFβ activation. Entresto (valsartan/sacubitril) was predicted to suppress fibrosis by valsartan suppression of ERK signaling and sacubitril enhancement of PKG activity, both of which decreased Smad3 activity. Overall, this study provides a framework for integrating drug-target mechanisms with logic-based network models, which can drive further studies both in cardiac fibrosis and other conditions.

The difference in referencing in Web of Science, Scopus, and Google Scholar

AIMS

How often a medical article is cited is important for many people because it is used to calculate different variables such as the h-index and the journal impact factor. The aim of this analysis was to assess how the citation count varies between Web of Science (WoS), Scopus, and Google Scholar in the current literature.

METHODS

We included the top 50 cited articles of four journals ESC Heart Failure; Journal of cachexia, sarcopenia and muscle; European Journal of Preventive Cardiology; and European Journal of Heart Failure in our analysis that were published between 1 January 2016 and 10 October 2019. We recorded the number of citations of these articles according to WoS, Scopus, and Google Scholar on 10 October 2019.

RESULTS

The top 50 articles in ESC Heart Failure were on average cited 12 (WoS), 13 (Scopus), and 17 times (Google Scholar); in Journal of cachexia, sarcopenia and muscle 37 (WoS), 43 (Scopus), and 60 times (Google Scholar); in European Journal of Preventive Cardiology 41 (WoS), 56 (Scopus), and 67 times (Google Scholar); and in European Journal of Heart Failure 76 (WoS), 108 (Scopus), and 230 times (Google Scholar). On average, the top 50 articles in all four journals were cited 41 (WoS), 52 (Scopus, 26% higher citations count than WoS, range 8-42% in the different journals), and 93 times (Google Scholar, 116% higher citation count than WoS, range 42-203%).

CONCLUSION

Scopus and Google Scholar on average have a higher citation count than WoS, whereas the difference is much larger between Google Scholar and WoS.

Highlights in heart failure

Heart failure (HF) remains a major cause of mortality, morbidity, and poor quality of life. It is an area of active research. This article is aimed to give an update on recent advances in all aspects of this syndrome. Major changes occurred in drug treatment of HF with reduced ejection fraction (HFrEF). Sacubitril/valsartan is indicated as a substitute to ACEi/ARBs after PARADIGM-HF (hazard ratio [HR], 0.80; 95% confidence interval [CI], 0.73 to 0.87 for sacubitril/valsartan vs. enalapril for the primary endpoint and Wei, Lin and Weissfeld HR 0.79, 95% CI 0.71-0.89 for recurrent events). Its initiation was then shown as safe and potentially useful in recent studies in patients hospitalized for acute HF. More recently, dapagliflozin and prevention of adverse-outcomes in DAPA-HF trial showed the beneficial effects of the sodium-glucose transporter type 2 inhibitor dapaglifozin vs. placebo, added to optimal standard therapy [HR, 0.74; 95% CI, 0.65 to 0.85;0.74; 95% CI, 0.65 to 0.85 for the primary endpoint]. Trials with other SGLT 2 inhibitors and in other patients, such as those with HF with preserved ejection fraction (HFpEF) or with recent decompensation, are ongoing. Multiple studies showed the unfavourable prognostic significance of abnormalities in serum potassium levels. Potassium lowering agents may allow initiation and titration of mineralocorticoid antagonists in a larger proportion of patients. Meta-analyses suggest better outcomes with ferric carboxymaltose in patients with iron deficiency. Drugs effective in HFrEF may be useful also in HF with mid-range ejection fraction. Better diagnosis and phenotype characterization seem warranted in HF with preserved ejection fraction. These and other burning aspects of HF research are summarized and reviewed in this article.

The clinical impact of growth differentiation factor-15 in heart disease: A 2019 update

Growth differentiation factor-15 (GDF-15), also known as macrophage inhibitory cytokine-1 (MIC-1) or non-steroidal anti-inflammatory drug-activated gene (NAG-1) has been identified as a biomarker of response to treatment and prognosis in cardiovascular diseases. GDF-15 is a member of the transforming growth factor-β superfamily and is involved in several pathological conditions such as inflammation, cancer, cardiovascular, pulmonary and renal diseases. Cardiac myocytes produce and secrete GDF-15 in response to oxidative stress, stimulation with angiotensin II or proinflammatory cytokines, ischemia, and mechanical stretch. Other cellular sources of GDF-15 production are macrophages, vascular smooth muscle cells, endothelial cells, and adipocytes, which secrete GDF-15 in response to oxidative or metabolic stress or stimulation of proinflammatory cytokines. GDF-15 is induced in hypertrophic and dilated cardiomyopathy after volume overload, ischemia, and heart failure. GDF-15 can be used as a marker of prognosis in patients with cardiovascular disorders, in combination with conventional prognostic factors, such as N-terminal pro B-type natriuretic peptide (NT-proBNP) and high-sensitivity troponin T (hs-TnT).

Open access efforts begin to bloom: ESC Heart Failure gets full attention and first impact factor

In 2014, the Heart Failure Association (HFA) of the European Society of Cardiology (ESC) founded the first open access journal focusing on heart failure, called ESC Heart Failure (ESC‐HF). In the first 5 years, in ESC‐HF we published more than 450 articles. Through ESC‐HF, the HFA gives room for heart failure research output from around the world. A transfer process from the European Journal of Heart Failure to ESC‐HF has also been installed. As a consequence, in 2018 ESC‐HF received 289 submissions, and published 148 items (acceptance rate 51%). The journal is listed in Scopus since 2014 and on the PubMed website since 2015. In 2019, we received our first impact factor from ISI Web of Knowledge / Thomson‐Reuters, which is 3.407 for 2018. This report reviews which papers get best cited. Not surprisingly, many of the best cited papers are reviews and facts & numbers mini reviews, but original research is also well cited.

Heart Failure in the Era of Precision Medicine: A Scientific Statement From the American Heart Association

One of 5 people will develop heart failure over his or her lifetime. Early diagnosis and better understanding of the pathophysiology of this disease are critical to optimal treatment. The “omics”—genomics, pharmacogenomics, epigenomics, proteomics, metabolomics, and microbiomics— of heart failure represent rapidly expanding fields of science that have, to date, not been integrated into a single body of work. The goals of this statement are to provide a comprehensive overview of the current state of these omics as they relate to the development and progression of heart failure and to consider the current and potential future applications of these data for precision medicine with respect to prevention, diagnosis, and therapy.

Cardiorenal Syndrome Revisited

Cardiorenal syndromes have been categorized into 5 clinical subtypes based on which organ is perceived to be the primary precipitant of the vicious and interrelated cycle of declining function in both organs. This clinical classification has broadened interest in cardiorenal interactions, but it is merely descriptive, does not rely on or inform predominant pathophysiology, and has produced little change in either practice or the research agenda. In contrast, recent scientific work identifies common pathophysiological pathways for several categories of cardiorenal syndromes, suggesting a unifying pathogenesis. Fibrosis is a common consequence of inflammation- and oxidative stress-related endothelial dysfunction in aging, hypertension, diabetes mellitus, obesity, ischemia, and organ injury. It is a common feature in heart failure and chronic kidney disease. Therefore, we suggest that fibrosis may be not only a marker but also the primary driver of pathophysiology in several cardiorenal syndromes. Interstitial fibrosis in the heart, large arteries, and kidneys may play a key role in the pathophysiology of the cardiorenal syndrome continuum. Focusing on fibrosis as a disease mediator might enable the identification of fibrosis-related biotargets that could potentially be modulated with renin-angiotensin-aldosterone system inhibitors, mineralocorticoid receptor antagonists, or other novel antifibrotic agents in development. This conceptual approach may be an effective new strategy for the prevention and treatment of fibrosis within the cardiorenal syndrome continuum.

Plasma protein biomarkers and their association with mutually exclusive cardiovascular phenotypes: the FIBRO-TARGETS case-control analyses

BACKGROUND

Hypertension, obesity and diabetes are major and potentially modifiable "risk factors" for cardiovascular diseases. Identification of biomarkers specific to these risk factors may help understanding the underlying pathophysiological pathways, and developing individual treatment.

METHODS

The FIBRO-TARGETS (targeting cardiac fibrosis for heart failure treatment) consortium has merged data from 12 patient cohorts in 1 common database of > 12,000 patients. Three mutually exclusive main phenotypic groups were identified ("cases"): (1) "hypertensive"; (2) "obese"; and (3) "diabetic"; age-sex matched in a 1:2 proportion with "healthy controls" without any of these phenotypes. Proteomic associations were studied using a biostatistical method based on LASSO and confronted with machine-learning and complex network approaches.

RESULTS

The case:control distribution by each cardiovascular phenotype was hypertension (50:100), obesity (50:98), and diabetes (36:72). Of the 86 studied proteins, 4 were found to be independently associated with hypertension: GDF-15, LEP, SORT-1 and FABP-2; 3 with obesity: CEACAM-8, LEP and PRELP; and 4 with diabetes: GDF-15, REN, CXCL-1 and SCF. GDF-15 (hypertension + diabetes) and LEP (hypertension + obesity) are shared by 2 different phenotypes. A machine-learning approach confirmed GDF-15, LEP and SORT-1 as discriminant biomarkers for the hypertension group, and LEP plus PRELP for the obesity group. Complex network analyses provided insight on the mechanisms underlying these disease phenotypes where fibrosis may play a central role.

CONCLUSION

Patients with "mutually exclusive" phenotypes display distinct bioprofiles that might underpin different biological pathways, potentially leading to fibrosis. Plasma protein biomarkers and their association with mutually exclusive cardiovascular phenotypes: the FIBRO-TARGETS case-control analyses. Patients with "mutually exclusive" phenotypes (blue: obesity, hypertension and diabetes) display distinct protein bioprofiles (green: decreased expression; red: increased expression) that might underpin different biological pathways (orange arrow), potentially leading to fibrosis.

Heart failure drug treatment

Heart failure is the most common cardiovascular reason for hospital admission for people older than 60 years of age. Few areas in medicine have progressed as remarkably as heart failure treatment over the past three decades. However, progress has been consistent only for chronic heart failure with reduced ejection fraction. In acutely decompensated heart failure and heart failure with preserved ejection fraction, none of the treatments tested to date have been definitively proven to improve survival. Delaying or preventing heart failure has become increasingly important in patients who are prone to heart failure. The prevention of worsening chronic heart failure and hospitalisations for acute decompensation is also of great importance. The objective of this Series paper is to provide a concise and practical summary of the available drug treatments for heart failure. We support the implementation of the international guidelines. We offer views on the basis of our personal experience in research areas that have insufficient evidence. The best possible evidence-based drug treatment (including inhibitors of the renin-angiotensin-aldosterone system and β blockers) is useful only when optimally implemented. However, implementation might be challenging. We believe that disease management programmes can be helpful in providing a multidisciplinary, holistic approach to the delivery of optimal medical care.

Potential spironolactone effects on collagen metabolism biomarkers in patients with uncontrolled blood pressure

BACKGROUND

An increase in myocardial collagen content may contribute to the development of heart failure; this might be inhibited or reversed by mineralocorticoid receptor antagonists (MRAs). We investigated changes in serum concentrations of the collagen synthesis biomarkers N-terminal propeptide of procollagen type III (PIIINP) (primary outcome) and C-terminal propeptide of procollagen type I (PICP) (secondary outcome) after non-randomised initiation of spironolactone as add-on therapy among patients with resistant hypertension enrolled in the 'Anglo-Scandinavian Cardiac Outcomes' trial (ASCOT).

METHODS

An age/sex matching plus propensity-scored logistic regression model incorporating variables related to the outcome and spironolactone treatment was created to compare patients treated with spironolactone for a 9-month period versus matched controls. A within-person analysis comparing changes in serum biomarker concentrations in the 9 months before versus after spironolactone treatment was also performed.

RESULTS

Patients included in the between-person analysis (n=146) were well matched: the mean age was 63±7 years and 11% were woman. Serum concentrations of PIIINP and PICP rose in 'controls' and fell during spironolactone treatment (adjusted means +0.52 (-0.05 to 1.09) vs -0.41 (-0.97 to 0.16) ng/mL, p=0.031 for PIIINP and +4.54(-1.77 to 10.9) vs -6.36 (-12.5 to -0.21) ng/mL, p=0.023 for PICP). For the within-person analysis (n=173), spironolactone treatment was also associated with a reduction in PICP (beta estimate=-11.82(-17.53 to -6.10) ng/mL, p<0.001) but not in PIIINP levels.

CONCLUSIONS

Treatment with spironolactone was associated with a reduction in serum biomarkers of collagen synthesis independently of blood pressure in patients with hypertension, suggesting that spironolactone might exert favourable effects on myocardial collagen synthesis and fibrosis. Whether this effect might contribute to slowing the progression to heart failure is worth investigating.

Rationale of the FIBROTARGETS study designed to identify novel biomarkers of myocardial fibrosis

Aims

Myocardial fibrosis alters the cardiac architecture favouring the development of cardiac dysfunction, including arrhythmias and heart failure. Reducing myocardial fibrosis may improve outcomes through the targeted diagnosis and treatment of emerging fibrotic pathways. The European‐Commission‐funded ‘FIBROTARGETS’ is a multinational academic and industrial consortium with the main aims of (i) characterizing novel key mechanistic pathways involved in the metabolism of fibrillary collagen that may serve as biotargets, (ii) evaluating the potential anti‐fibrotic properties of novel or repurposed molecules interfering with the newly identified biotargets, and (iii) characterizing bioprofiles based on distinct mechanistic phenotypes involving the aforementioned biotargets. These pathways will be explored by performing a systematic and collaborative search for mechanisms and targets of myocardial fibrosis. These mechanisms will then be translated into individualized diagnostic tools and specific therapeutic pharmacological options for heart failure.

Methods and results

The FIBROTARGETS consortium has merged data from 12 patient cohorts in a common database available to individual consortium partners. The database consists of >12 000 patients with a large spectrum of cardiovascular clinical phenotypes. It integrates community‐based population cohorts, cardiovascular risk cohorts, and heart failure cohorts.

Conclusions

The FIBROTARGETS biomarker programme is aimed at exploring fibrotic pathways allowing the bioprofiling of patients into specific ‘fibrotic’ phenotypes and identifying new therapeutic targets that will potentially enable the development of novel and tailored anti‐fibrotic therapies for heart failure.