Growth differentiation factor-15 predicts mortality and morbidity after cardiac resynchronization therapy

Prognostic value of growth differentiation factor-15 in heart failure among whole ejection fraction phenotypes

AIMS

The utility of growth differentiation factor-15 (GDF-15) in predicting long-term adverse outcomes in heart failure (HF) patients is not well established. This study explored the relationship between GDF-15 levels and adverse outcomes in HF patients across various ejection fraction (EF) phenotypes associated with coronary heart disease (CHD) and evaluated the added prognostic value of incorporating GDF-15 into the Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC) risk score-based model.

METHODS AND RESULTS

This single-centre cohort study included 823 HF patients, categorized into 230 (27.9%) reduced EF (HFrEF), 271 (32.9%) mid-range EF (HFmrEF), and 322 (39.1%) preserved EF (HFpEF) groups. The median age was 68.0 years (range: 56.0-77.0), and 245 (29.8%) were females. Compared with the HFrEF and HFmrEF groups, the HFpEF group had a higher GDF-15 concentration (P = 0.002) and a higher MAGGIC risk score (P < 0.001). We examined the associations between GDF-15 levels and the risks of all-cause mortality and HF rehospitalization using Cox regression models. The C-index, integrated discrimination improvement (IDI), and net reclassification improvement (NRI) metrics were employed to assess the incremental prognostic value. During the 9.4 year follow-up period, 425 patients died, and 484 were rehospitalized due to HF. Multivariate Cox regression analysis revealed that elevated GDF-15 levels were significantly associated with an increased risk of all-cause mortality [hazard ratio (HR) = 1.36, 95% confidence interval (CI): 1.20-1.54; P < 0.001] and HF rehospitalization (HR = 1.75, 95% CI: 1.57-1.95; P < 0.001) across all HF phenotypes. This association remained significant when GDF-15 was treated as a categorical variable (high GDF-15 group: all-cause death: HR = 1.73, 95% CI: 1.40-2.14; P < 0.001; HF rehospitalization: HR = 3.37, 95% CI: 2.73-4.15; P < 0.001). Inclusion of GDF-15 in the MAGGIC risk score-based model provided additional prognostic value for all HF patients (Δ C-index = 0.021, 95% CI: 0.002-0.041; IDI = 0.011, 95% CI: 0.001-0.025; continuous NRI = 0.489, 95% CI: 0.174-0.629) and HF rehospitalization (Δ C-index = 0.034, 95% CI: 0.005-0.063; IDI = 0.021, 95% CI: 0.007-0.032; continuous NRI = 0.307, 95% CI: 0.147-0.548), particularly in the HFpEF subgroup.

CONCLUSIONS

GDF-15 is identified as an independent risk factor for adverse outcomes in HF patients across the entire EF spectrum in the context of CHD. Integrating GDF-15 into the MAGGIC risk score-based model enhances its prognostic capability for adverse outcomes in the general HF population. This incremental prognostic effect was observed specifically in the HFpEF subgroup and not in other subgroups.

Growth and differentiation factor-15: A link between inflammaging and cardiovascular disease

Age-related disorders are closely linked to the accumulation of senescent cells. The senescence-associated secretory phenotype (SASP) sustains and progresses chronic inflammation, which is involved in cellular and tissue dysfunction. SASP-related growth and differentiation factor-15 (GDF-15) is an immunoregulatory cytokine that is coupled to aging and thus may have a regulatory role in the development and maintenance of atherosclerosis, a major cause of cardiovascular disease (CVD). Although the effects of GDF-15 are tissue-specific and dependent on microenvironmental changes such as inflammation, available data suggest that GDF-15 has a significant role in CVD. Thus, GDF-15 is a promising biomarker and potential therapeutic target for atherosclerotic CVD.

Growth Differentiation Factor 15 (GDF-15), a New Biomarker in Heart Failure Management

The emergence of biomarkers across medicine's subspecialties continues to evolve. In essence, a biomarker is a biological observation that clearly substitutes a clinical endpoint or intermediate outcome not only are more difficult to observe but also, biomarkers are easier, less expensive and could be measured over shorter periods. In general, biomarkers are versatile and not only used for disease screening and diagnosis but, most importantly, for disease characterization, monitoring, and determination of prognosis as well as individualized therapeutic responses. Obviously, heart failure (HF) is no exception to the use of biomarkers. Currently, natriuretic peptides are the most used biomarkers for both diagnosis and prognostication, while their role in the monitoring of treatment is still debatable. Although several other new biomarkers are currently under investigation regarding diagnosis and determination of prognosis, none of them are specific for HF, and none are recommended for routine clinical use at present. However, among these emerging biomarkers, we would like to highlight the potential for growth differentiation factor (GDF)-15 as a plausible new biomarker that could be helpful in providing prognostic information regarding HF morbidity and mortality.

Frataxin deficiency alters gene expression in Friedreich ataxia derived IPSC-neurons and cardiomyocytes

BACKGROUND

Friedreich's ataxia (FRDA) is an autosomal recessive disease, whereby homozygous inheritance of an expanded GAA trinucleotide repeat expansion in the first intron of the FXN gene leads to transcriptional repression of the encoded protein frataxin. FRDA is a progressive neurodegenerative disorder, but the primary cause of death is heart disease which occurs in 60% of the patients. Several functions of frataxin have been proposed, but none of them fully explain why its deficiency causes the FRDA phenotypes nor why the most affected cell types are neurons and cardiomyocytes.

METHODS

To investigate, we generated iPSC-derived neurons (iNs) and cardiomyocytes (iCMs) from an FRDA patient and upregulated FXN expression via lentivirus without altering genomic GAA repeats at the FXN locus.

RESULTS

RNA-seq and differential gene expression enrichment analyses demonstrated that frataxin deficiency affected the expression of glycolytic pathway genes in neurons and extracellular matrix pathway genes in cardiomyocytes. Genes in these pathways were differentially expressed when compared to a control and restored to control levels when FRDA cells were supplemented with frataxin.

CONCLUSIONS

These results offer novel insight into specific roles of frataxin deficiency pathogenesis in neurons and cardiomyocytes.

A label-free amperometric immunosensor with improved electrocatalytic 3D braided AuPtCu-SWCNTs@MoS2-rGO for human growth differentiation factor-15 detection

Growth differentiation factor-15 (GDF-15) is a member of the transforming growth factor-β family. GDF-15 is overexpressed in cardiovascular diseases and has become a novel biomarker for these diseases. In this study, we fabricated a label-free electrochemical immunosensor for sensitive detection of GDF-15. Briefly, a three-dimensional braided composite of AuPtCu-SWCNTs@MoS₂-rGO (denoted A@M), which served as a label-free immunosensor platform, was obtained by wrapping single-walled carbon nanotubes (SWCNTs) with trimetallic nanoflowers (AuPtCu NFs) woven on a three-dimensional network nanostructure composed of Molybdenum disulfide (MoS₂) and reduced graphene oxide (rGO) nanosheets. This optimization improved the ability of the platform to immobilize antibodies, accelerated the reduction of hydrogen peroxide, and promoted the migration rate of electrons on the electrode surface, thereby further amplifying the electrical signal and improving the sensitivity. The constructed sensor exhibited high sensitivity over a wide linear range from 1 pg mL^-1 to 50 ng mL^-1, with a low detection limit of 0.825 pg mL^-1 for GDF-15. The fabricated label-free immunosensor exhibits satisfactory reproducibility, selectivity, and stability. The detection of actual samples was successful, enabling a broad scope of application in the early diagnosis, prognosis, and treatment of cardiovascular diseases.

Growth/differentiation factor-15 (GDF-15) as a predictor of serious arrhythmic events in patients with nonischemic dilated cardiomyopathy

INTRODUCTION

Cardiac biomarkers have been proposed as a new tool to improve risk stratification of serious arrhythmic events in patients with heart failure (HF) beyond estimates of left ventricular ejection fraction. Growth differentiation factor (GDF)-15, a stress-induced cytokine, has been found to correlate with markers of myocardial fibrosis and adverse clinical outcomes, but its role as a predictor of arrhythmic events in patients with nonischemic HF is uncertain.

METHODS AND RESULTS

A prospective observational study was conducted in 148 nonischemic patients with HF who underwent comprehensive clinical and laboratory evaluation, including measurement of serum GDF-15. The study endpoints were serious arrhythmic events (which included appropriate implantable cardioverter-defibrillator therapy and sudden cardiac death) and all-cause mortality. Mean age of the cohort was 54.8 ± 12.7 years, and mean left ventricular ejection fraction (LVEF) was 27.4% ± 7.5%. During a mean follow-up time of 42 months, arrhythmic events occurred in 28 patients (19%), and 40 patients (27%) died. An increase in serum GDF-15 (log-transformed) correlated linearly with a higher risk of serious arrhythmic events (HR 1.14, 95% CI 1.01-1.28, p = 0.03) even after adjustment for other potential clinical predictors (HR 1.16, 95% CI 1.02-1.32, p = 0.02). GDF-15 was also strongly and independently associated with all-cause mortality (HR 1.17, 1.05-1.31, p = 0.004).

CONCLUSION

In this cohort of nonischemic HF patients on optimized medical treatment, serum GDF-15 levels were independently associated with major arrhythmic events and overall mortality. This biomarker may add prognostic information to better stratify the risk of sudden death in this particular population.

Growth differentiating factor-15 and adiposity in young adults: The African-PREDICT study

BACKGROUND AND AIMS

Circulating growth differentiation factor-15 (GDF-15) is a stress-responsive cytokine that increases in older individuals with established cardiovascular disease (CVD) and obesity. To address potential targets in primary prevention, we aimed to determine whether body weight, waist circumference, waist/height ratio, body mass index (BMI), body surface area (BSA) and leptin associate with GDF-15 in young underweight, lean and overweight/obese (ow/ob) adults.

METHODS AND RESULTS

We included 1189 adults aged 20-30 years. We grouped participants as underweight (BMI ≤ 18 kg/m², n = 59), lean (BMI > 18 kg/m² and ≤25 kg/m²; n = 616) or ow/ob (BMI ≥ 25 kg/m²; n = 514) and determined serum GDF-15 and leptin levels. Body composition measurements, leptin and blood pressure readings were higher in the ow/ob group compared to the underweight and lean groups (all p < 0.0001). GDF-15 was higher in the underweight group compared to the lean and combined ow/ob groups (p = 0.041), and higher in obese (BMI ≥ 30 kg/m²) compared to overweight (p = 0.002) individuals. In multiple regression analysis, we found positive associations (all p ≤ 0.020) of body weight (adj. R² = 0.398; β = 0.11), waist circumference (adj. R² = 0.271; β = 0.11), waist/height ratio (adj. R² = 0.168; β = 0.14), BMI (adj. R² = 0.263; β = 0.14), BSA (adj. R² = 0.508; β = 0.083) and leptin (adj. R² = 0.622; β = 0.10) with GDF-15 in the ow/ob group. However, waist circumference (adj. R² = 0.536; β = -0.45), waist/height ratio (adj. R² = 0.471; β = -0.51) and leptin (adj. R² = 434; β = -0.25) associated inversely with GDF-15 in the underweight group (all p < 0.050).

CONCLUSION

Our findings may suggest that in young adults with either underweight or excess adiposity, increased GDF-15 levels may contribute to the development of future cardiovascular health risks associated with pro-inflammation.

GDF-15 as a Biomarker in Cardiovascular Disease

In the last years, several diagnostic and prognostic biomarkers have been studied in cardiovascular disease. Growth differentiation factor-15 (GDF-15), a cytokine belonging to the transforming growth factor- (TGF-) family, is highly up-regulated in stress and inflammatory conditions and has been correlated to myocardial injury and pressure cardiac overload in animal models. This new biomarker has been positively correlated with increased risk of cardiovascular events in population studies and shown an independent predictor of mortality in patients with coronary artery disease and heart failure. This review aimed to summarize the current evidence on the diagnostic and prognostic value of GDF-15 in different settings in cardiology.

Transcriptome changes for Nile tilapia (Oreochromis niloticus) in response to alkalinity stress

Nile tilapia is an important economic fish in the world because of its fast growth, high meat yield and strong adaptability. It is more adaptable to high alkalinity than common freshwater fish and provides valuable material for developing alkaline-tolerant strains and understanding the adaptation mechanism of fish to extreme environmental stress. In this study, we employed high throughput RNA sequencing to reveal the tissues (gill, kidney and liver) transcriptome differences of O. niloticus at different carbonate alkalinities (FW, AW40 and AW60). A total of 1,369,381,790 raw reads were obtained, including 496,441,232 reads in FW group, 437,907,696 reads in AW40 and 435,032,862 reads in AW60. In addition, 484,555,626 reads in gill, 451,618,224 reads in kidney and 433,207,940 reads in liver. A large number of stress-regulated changes were detected comprehensively. We focused on 3 significantly change pathways (steroid biosynthesis, drug metabolism and protein digestion/absorption) and 17 DEGs (HMG-CoA reductase, UDP-glucuronosyltransferase, and carbonic anhydrase etc.) which were shared among compared groups (AW40 vs FW, AW60 vs FW, AW40 vs 60 AW60) in gill, kidney and liver, respectively. These pathways/genes are sensitive to alkalinity stress and crucial to the alkalinity adaptation of tilapia. Overall, we found a large number of candidate genes, which encode important regulators of stress tolerance and ultimately contribute to future alkaline-tolerant fish breeding. Among these genes, lipid metabolism (involving signal transduction), detoxification and immune related genes are more prominent to the response and adaptability of fish to alkalinity stress.

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).

Growth differentiation factor-15 combined with N-terminal prohormone of brain natriuretic peptide increase 1-year prognosis prediction value for patients with acute heart failure: a prospective cohort study

BACKGROUND

Clinical assessment and treatment guidance for heart failure depends on a variety of biomarkers. The objective of this study was to investigate the prognostic predictive value of growth differentiation factor-15 (GDF-15) and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) in assessing hospitalized patients with acute heart failure (AHF).

METHODS

In total, 260 patients who were admitted for AHF in the First Affiliated Hospital of Nanjing Medical University were enrolled from April 2012 to May 2016. Medical history and blood samples were collected within 24 h after the admission. The primary endpoint was the all-cause mortality within 1 year. The patients were divided into survival group and death group based on the endpoint. With established mortality risk factors and serum GDF-15 level, receiver-operator characteristic (ROC) analyses were performed. Cox regression analyses were used to further analyze the combination values of NT-proBNP and GDF-15.

RESULTS

Baseline GDF-15 and NT-proBNP were significantly higher amongst deceased than those in survivors (P < 0.001). In ROC analyses, area under curve (AUC) for GDF-15 to predict 1-year mortality was 0.707 (95% confidence interval [CI]: 0.648-0.762, P < 0.001), and for NT-proBNP was 0.682 (95% CI: 0.622-0.738, P < 0.001). No statistically significant difference was found between the two markers (P = 0.650). Based on the optimal cut-offs (GDF-15: 4526.0 ng/L; NT-proBNP: 1978.0 ng/L), the combination of GDF-15 and NT-proBNP increased AUC for 1-year mortality prediction (AUC = 0.743, 95% CI: 0.685-0.795, P < 0.001).

CONCLUSIONS

GDF-15, as a prognostic marker in patients with AHF, is not inferior to NT-proBNP. Combining the two markers could provide an early recognition of high-risk patients and improve the prediction values of AHF long-term prognosis.

CLINICAL TRIAL REGISTRATION

ChiCTR-ONC-12001944, http://www.chictr.org.cn.

Growth differentiation factor-15 and the risk of cardiovascular diseases and all-cause mortality: A meta-analysis of prospective studies

Background and Aim

Previous studies have documented that the association between growth differentiation factor‐15 (GDF‐15) the risk of patients with cardiovascular diseases (CVDs). In this meta‐analysis, our main objective is to explore the associations between GDF‐15 and the risk of CVD or all‐cause mortality.

Methods

PubMed and ISI Web of Science (up to January 2018) electronic databases were browsed for eligible studies. The studies provided relevant data depicted as hazard ratio (HR) with 95% confidence interval (CI), with regard to the association between GDF‐15 levels and subsequent risk of CVDs or all‐cause mortality. A random‐effect model was applied to pool the HR and 95% CI.

Results

Thirty‐one prospective studies met the eligibility criteria involving 53 706 subjects with 7020 adverse outcome events. It was concluded that GDF‐15 levels were associated with an incremental risk of CVDs or all‐cause mortality. Highest GDF‐15 category was associated with greater risk of cardiovascular mortality (HR, 2.66; 95% CI, 1.69‐3.63), all‐cause mortality (HR, 2.52; 95% CI, 2.06‐2.97), and complex adverse outcome (HR, 1.81; 95% CI, 1.42‐2.21). As each log‐unit increment in GDF‐15 concentration, the corresponding risk of adverse events also escalated, cardiovascular mortality (HR, 2.11; 95% CI, 1.57‐2.66), all‐cause mortality (HR, 2.70; 95% CI, 2.29‐3.12), and complex adverse outcome (HR, 1.96; 95% CI, 1.64‐2.29).

Conclusions

Judging from the results of the data analysis, GDF‐15 levels may increase the risk of CVDs or all‐cause mortality.

Characterisation of circulating biomarkers before and after cardiac resynchronisation therapy and their role in predicting CRT response: the COVERT-HF study

Aims

Cardiac resynchronisation therapy (CRT) is effective treatment for selected patients with heart failure (HF) but has ~30% non-response rate. We evaluated whether specific biomarkers can predict outcome.

Methods

A prospective single-centre pilot study of consecutive unselected patients undergoing CRT for HF between November 2013 and December 2015 evaluating cardiac extracellular matrix biomarkers and micro-ribonucleic acid (miRNA) expression before and after CRT assessing ability to predict functional response and survival. Each underwent three assessments (pre-implant, 6  weeks and 6  months postimplant) including: New York Heart Association (NYHA) class, echocardiography, electrocardiography, 6  min walk test (6MWT), Minnesota Living with Heart Failure Questionnaire (MLHFQ) and N-terminal pro-brain natriuretic peptide (NT-pro-BNP). Plasma markers of cardiac fibrosis assessed were: N-terminal pro-peptides of collagen I and III, collagen I C-terminal telopeptides (CTx) and matrix metalloproteinases (MMP-2 and MMP-9) as well as a panel of miRNAs (miRNA-21, miRNA-30d, miRNA-122, miRNA-133a, miRNA-210 and miRNA-486).

Results

A total of 52 patients were recruited; mean age (±SD) was 72.4±9.4 years; male=43 (82.7%), ischaemic aetiology=30 (57.7%), mean QRS duration=166.4±23.5  ms, left bundle branch block (LBBB) morphology = 39 (75.0%), mean NYHA=2.7±0.6, 6MWT=238.8±130.6  m, MLHFQ=46.4±21.3  and left ventricular ejection fraction (LVEF)=24.3%±8.0%. Mean follow-up=1.7±0.3  and 5.8±0.7 months. There were 27 (55.1%) functional responders (3 no definable 6-month response; 2 missed assessments and 1 long-term lead displacement). No marker predicted response, however, CTx and LBBB trended most towards predicting functional response.

Conclusion

No specific biomarkers reached significance for predicting functional response to CRT. CTx showed a trend towards predicting response and warrants further study.

Trial registration number

NCT02541773.

Growth Differentiation Factor-15 as a Predictor of Idiopathic Membranous Nephropathy Progression: A Retrospective Study

Idiopathic membranous nephropathy (IMN) is a major cause of nephrotic syndrome. No biomarker to predict the long-term prognosis of IMN is currently available. Growth differentiation factor-15 (GDF-15) is a member of the transforming growth factor-β superfamily and has been associated with chronic inflammatory disease. It has the potential to be a useful prognostic marker in patients with renal diseases, such as diabetic nephropathy and IgA nephropathy. This study examined whether GDF-15 is associated with the clinical parameters in IMN and showed that GDF-15 can predict IMN disease progression. A total of 35 patients with biopsy-proven IMN, treated at Chungnam National University Hospital from January 2010 to December 2015, were included. Patients younger than 18 years, those with secondary membranous nephropathy, and those lost to follow-up before 12 months were excluded. Levels of GDF-15 at the time of biopsy were measured using enzyme-linked immunosorbent assays. Disease progression was defined as a ≥30% decline in estimated glomerular filtration rate (eGFR) or the development of end-stage renal disease. The mean follow-up was 44.1 months (range: 16–72 months). Using receiver operating curve analysis, the best serum GDF-15 cut-off value for predicting disease progression was 2.15 ng/ml (sensitivity: 75.0%, specificity: 82.1%, p = 0.007). GDF-15 was significantly related to age and initial renal function. In the Kaplan-Meier analysis, the risk of disease progression increased in patients with GDF-15 ≥ 2.15 ng/ml when compared with those with GDF-15 < 2.15 ng/ml (50.0% versus 9.7%) (p = 0.012). In the multivariate Cox regression analysis adjusted for potential confounders, only GDF-15 was significantly associated with disease progression in IMN (p = 0.032). In conclusion, the GDF-15 level at the time of diagnosis has a significant negative correlation with initial renal function and is associated with a poor prognosis in IMN. Our results suggest that GDF-15 provides useful prognostic information in patients with IMN.

Refining success of cardiac resynchronization therapy using a simple score predicting the amount of reverse ventricular remodelling: results from the Markers and Response to CRT (MARC) study

Aims

Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in systolic heart failure patients with ventricular conduction delay. Variability of individual response to CRT warrants improved patient selection. The Markers and Response to CRT (MARC) study was designed to investigate markers related to response to CRT.

Methods and results

We prospectively studied the ability of 11 clinical, 11 electrocardiographic, 4 echocardiographic, and 16 blood biomarkers to predict CRT response in 240 patients. Response was measured by the reduction of indexed left ventricular end-systolic volume (LVESVi) at 6 months follow-up. Biomarkers were related to LVESVi change using log-linear regression on continuous scale. Covariates that were significant univariately were included in a multivariable model. The final model was utilized to compose a response score. Age was 67 ± 10 years, 63% were male, 46% had ischaemic aetiology, LV ejection fraction was 26 ± 8%, LVESVi was 75 ± 31 mL/m2, and QRS was 178 ± 23 ms. At 6 months LVESVi was reduced to 58 ± 31 mL/m2 (relative reduction of 22 ± 24%), 130 patients (61%) showed ≥ 15% LVESVi reduction. In univariate analysis 17 parameters were significantly associated with LVESVi change. In the final model age, QRSAREA (using vectorcardiography) and two echocardiographic markers (interventricular mechanical delay and apical rocking) remained significantly associated with the amount of reverse ventricular remodelling. This CAVIAR (CRT-Age-Vectorcardiographic QRSAREA -Interventricular Mechanical delay-Apical Rocking) response score also predicted clinical outcome assessed by heart failure hospitalizations and all-cause mortality.

Conclusions

The CAVIAR response score predicts the amount of reverse remodelling after CRT and may be used to improve patient selection. Clinical Trials: NCT01519908.

Growth-differentiation factor 15 as a predictor of mortality in patients with heart failure: a meta-analysis

AIMS

Measurement of the biomarker growth-differentiation factor 15 (GDF-15) in patients with heart failure may help in risk stratification. We assessed the relationship between GDF-15 and mortality in patients with heart failure by conducting a meta-analysis.

METHODS

PubMed, Embase, ISI Web of Science, SCOPUS, and Cochrane Library databases were searched for studies that reported data on the baseline GDF-15 levels and all-cause or cardiovascular mortality. Pooled hazard ratios for mortality were calculated and presented with 95% confidence intervals (CIs). Potential sources of heterogeneity were assessed by meta-regression, subgroup, and sensitivity analyses.

RESULTS

Eight studies with a total of 4126 heart failure patients were included. Pooled results showed that overexpression of GDF-15 was associated with poor survival in heart failure patients (log unit GDF-15: hazard ratio = 1.86, 95% CI = 1.37-2.52). Subgroup analyses revealed similar results. However, there was evidence of heterogeneity and publication bias. The association disappeared after correction using the trim-and-fill method (log unit GDF-15: hazard ratio 1.07, 95% CI 0.80-1.42).

CONCLUSION

The results of this meta-analysis indicate an association of elevated GDF-15 levels with increased risk of mortality in patients with heart failure. However, the results should be interpreted with caution due to substantial heterogeneity and publication bias among the studies included in the meta-analysis.

Growth Differentiation Factor 15 as a Biomarker in Cardiovascular Disease

BACKGROUND

Growth differentiation factor 15 (GDF-15) is expressed and secreted in response to inflammation, oxidative stress, hypoxia, telomere erosion, and oncogene activation. Cardiovascular (CV) disease is a major driver of GDF-15 production. GDF-15 has favorable preanalytic characteristics and can be measured in serum and plasma by immunoassay.

CONTENT

In community-dwelling individuals higher concentrations of GDF-15 are associated with increased risks of developing CV disease, chronic kidney disease, and cancer, independent of traditional CV risk factors, renal function, and other biomarkers (C-reactive protein, B-type natriuretic peptide, cardiac troponin). Low concentrations of GDF-15 are closely associated with longevity. GDF-15 is as an independent marker of all-cause mortality and CV events in patients with coronary artery disease, and may help select patients with non-ST-elevation acute coronary syndrome for early revascularization and more intensive medical therapies. GDF-15 is independently associated with mortality and nonfatal events in atrial fibrillation and heart failure (HF) with preserved or reduced ejection fraction. GDF-15 reflects chronic disease burden and acute perturbations in HF and responds to improvements in hemodynamic status. GDF-15 is independently associated with major bleeding in patients receiving antithrombotic therapies and has been included in a new bleeding risk score, which may become useful for decision support.

SUMMARY

GDF-15 captures distinct aspects of CV disease development, progression, and prognosis, which are not represented by clinical risk predictors and other biomarkers. The usefulness of GDF-15 to guide management decisions and discover new treatment targets should be further explored.

Diabetes mellitus related biomarker: The predictive role of growth-differentiation factor-15

Growth differentiation factor-15 (GDF-15) is a stress-responsive cytokine, which belongs to super family of the transforming growth factor beta. GDF-15 is widely presented in the various cells (macrophages, vascular smooth muscle cells, adipocytes, cardiomyocytes, endothelial cells, fibroblasts), tissues (adipose tissue, vessels, tissues of central and peripheral nervous system) and organs (heart, brain, liver, placenta) and it plays an important role in the regulation of the inflammatory response, growth and cell differentiation. Elevated GDF-15 was found in patients with established CV diseases including hypertension, stable coronary artery disease, acute coronary syndrome, myocardial infarction, ischemic and none ischemic-induced cardiomyopathies, heart failure, atrial fibrillation, as well as stroke, type two diabetes mellitus (T2DM), chronic kidney disease, infection, liver cirrhosis, malignancy. Therefore, aging, smoking, and various environmental factors, i.e. chemical pollutants are other risk factors that might increase serum GDF-15 level. Although GDF-15 has been reported to be involved in energy homoeostasis and weight loss, to have anti-inflammatory properties, and to predict CV diseases and CV events in general or established CV disease population, there is no large of body of evidence regarding predictive role of elevated GDF-15 in T2DM subjects. The mini review is clarified the role of GDF-15 in T2DM subjects.

Biomarkers for risk prediction in acute decompensated heart failure

Risk prediction in patients admitted with acute decompensated heart failure (ADHF) remains a challenge. Biomarkers may improve risk prediction, which in turn may help to better inform patients regarding short-term and long-term prognosis, therapy and care. Most data on biomarkers have been derived from patient cohorts with chronic heart failure. In ADHF, currently, risk tools largely rely on common clinical and biochemical parameters. However, ADHF is not a single disease. It presents in various manners and different etiologies may underlie ADHF, which are reflected by different biomarkers. In the last decade, many studies have reported the prognostic value of these biomarkers. These studies have attempted to describe a value for statistical modeling, e.g., reclassification indices, in an effort to report incremental value over a clinical model or the "gold standard". However, the overall incremental predictive value of biomarkers has been modest compared to already existing clinical models. Natriuretic peptides, e.g., (NTpro-)BNP, are the benchmark, but head-to-head comparisons show that there are novel biomarkers with comparable prognostic value. Multimarker strategies may provide superior risk stratification. Future studies should elucidate cost-effectiveness of single or combined biomarker testing. The purpose of this review was to provide an update on current biomarkers and to identify new promising biomarkers than can be used in prognostication of acute heart failure.

Validation of a simple risk stratification tool for patients implanted with Cardiac Resynchronization Therapy: the VALID-CRT risk score

AIMS

Mortality after cardiac resynchronization therapy (CRT) is difficult to predict. We sought to design and validate a simple prognostic score for patients implanted with CRT, based on readily available clinical variables, including age, gender, left ventricular ejection fraction (LVEF), New York Heart Association (NYHA) class, presence/absence of atrial fibrillation, presence/absence of atrioventricular junction ablation, coronary heart disease, diabetes, and implantation of a CRT device with defibrillation.

METHODS

For predictive modelling, 5153 consecutive patients enrolled in 72 European centres (79% male; LVEF 25.9 ± 6.85%; NYHA class III-IV 77.5%; QRS 158.4 ± 32.3 ms) were randomly split into derivation (70%) and validation (30%) samples. The primary endpoint was total mortality and the secondary endpoint was cardiovascular mortality. The final predictive model fit was assessed by plotting observed vs. predicted survival.

RESULTS

In the entire cohort, 1004 deaths occurred over a follow-up of 14 409 person years. Total mortality ranged from 3.1% to 28.2% at 2 years in the first and fifth quintile of the risk score, respectively. At 5 years, total mortality was 10.3%, 18.6%, 27.6%, 36.1%, and 58.8%, from the first to the fifth quintile. Compared with the lowest quintile (Q), total mortality was significantly higher in the other four quintiles [Q2 hazard ratio (HR) = 1.71; Q3 HR = 2.20; Q4 HR = 4.03; Q5 HR = 8.03; all P < 0.001). The final model, which was based on the entire cohort using the above variables, showed a good discrimination (Harrell's c = 0.70) and high explained variation (0.26). The mean predicted survival fitted well with the observed survival for up to 6 years of follow-up.

CONCLUSIONS

The VALID-CRT risk score, which is based on routine, readily available clinical variables, reliably predicted the long-term total and cardiovascular mortality in patients undergoing CRT. While this score cannot be used to predict the benefit of CRT, it may be useful for predicting survival after CRT. This may have useful implications for follow-up.

Sex differences in device therapy for heart failure: utilization, outcomes, and adverse events

BACKGROUND

Multiple studies of heart failure patients demonstrated significant improvement in exercise capacity, quality of life, cardiac left ventricular function, and survival from cardiac resynchronization therapy (CRT), but the underenrollment of women in these studies is notable. Etiological and pathophysiological differences may result in different outcomes in response to this treatment by sex. The observed disproportionate representation of women suggests that many women with heart failure either do not meet current clinical criteria to receive CRT in trials or are not properly recruited and maintained in these studies.

METHODS

We performed a systematic literature review through May 2014 of clinical trials and registries of CRT use that stratified outcomes by sex or reported percent women included. One-hundred eighty-three studies contained sex-specific information.

RESULTS

Ninety percent of the studies evaluated included ≤ 35% women. Fifty-six articles included effectiveness data that reported response with regard to specific outcome parameters. When compared with men, women exhibited more dramatic improvement in specific parameters. In the studies reporting hazard ratios for hospitalization or death, women generally had greater benefit from CRT.

CONCLUSIONS

Our review confirms women are markedly underrepresented in CRT trials, and when a CRT device is implanted, women have a therapeutic response that is equivalent to or better than in men, while there is no difference in adverse events reported by sex.

Biomarkers in electrophysiology: role in arrhythmias and resynchronization therapy

Circulating biomarkers related to inflammation, neurohormones, myocardial stress, and necrosis have been associated with commonly encountered arrhythmic disorders such as atrial fibrillation (AF) and more malignant processes including ventricular arrhythmias (VA) and sudden cardiac death (SCD). Both direct and indirect biomarkers implicated in the heart failure cascade have potential prognostic value in patients undergoing cardiac resynchronization therapy (CRT). This review will focus on the role of biomarkers in AF, history of SCD, and CRT with an emphasis to improve clinical risk assessment for arrhythmias and patient selection for device therapy. Notably, information obtained from biomarkers may supplement traditional diagnostic and imaging techniques, thus providing an additional benefit in the management of patients.

Growth differentiation factor-15 (GDF-15) levels are associated with cardiac and renal injury in patients undergoing coronary artery bypass grafting with cardiopulmonary bypass

OBJECTIVE

Growth differentiation factor-15 (GDF-15) has been identified as a strong marker of cardiovascular disease; however, no data are available concerning the role of GDF-15 in the occurrence of organ dysfunction during coronary artery bypass grafting (CABG) associated with cardiopulmonary bypass (CPB).

METHODS

Five arterial blood samples were taken sequentially in 34 patients from anesthesia induction (IND) until 24 h after arrival at the intensive care unit (ICU). Plasma levels of GDF-15, follistatin-like 1 (FLST1), myeloperoxidases (MPO), hydroperoxides and plasma antioxidant status (PAS) were measured at each time-point. Markers of cardiac (cardiac-troponin I, cTnI) and renal dysfunction (neutrophil gelatinase-associated lipocalin, NGAL) and other classical biological factors and clinical data were measured.

RESULTS

Plasma GDF-15 levels increased gradually during and after surgery, reaching nearly three times the IND levels in the ICU (3,075±284 ng/L vs. 1,061±90 ng/L, p<0.001). Plasma MPO levels increased dramatically during surgery, attaining their highest level after unclamping (UNCLAMP) (49±11 ng/mL vs. 1,679±153 ng/mL, p<0.001) while PAS significantly decreased between IND and UNCLAMP (p<0.05), confirming the high oxidative status induced by this surgical procedure. ICU levels of GDF-15 correlated positively with cTnI and NGAL (p = 0.006 and p = 0.036, respectively), and also with hemoglobin and estimated glomerular filtration rate (eGFR). Among all the post-operative biomarkers available, only eGFR, NGAL and GDF-15 measured at ICU arrival were significantly associated with the onset of acute kidney injury (AKI). Patients with a EuroSCORE >3 were shown to have higher GDF-15 levels.

CONCLUSIONS

During cardiac surgery associated with CPB, GDF-15 levels increased substantially and were associated with markers of cardiac injury and renal dysfunction.

Concise review: growth differentiation factor 15 in pathology: a clinical role?

Growth differentiation factor 15 (GDF15) is a divergent member of the transforming growth factor β family discovered in a broad range of cells, as indicated by the diversity of its nomenclature. However, the only tissue that expresses a high amount of GDF15 in the physiologic state is placenta. GDF15 is easily detected in blood, and its concentration varies with age. In fact, increased blood concentration of GDF15 is associated with numerous pathological conditions. However, the biological significance underlying these observations is far from clear. GDF15 could have a positive or negative role depending on the state of cells or their environment. Furthermore, study of its biology is hampered by lack of knowledge of its receptor and thus the signaling pathways that drive its action. GDF15 seems to be an integrative signal in pathologic conditions, giving information on severity of disease. Its effectiveness in classifying patients to modulate treatment remains to be shown. Development of therapeutic interventions with GDF15 or anti-GDF15 agents remains difficult until we uncover the mechanism that drives its activity.

Novel biomarkers in chronic heart failure

Understanding of chronic heart failure (HF) has progressed from a syndrome of disordered hemodynamics caused by alterations in the structure of the heart to one that involves intertwined molecular pathways in disarray. Accordingly, the assessment and treatment of patients with chronic HF has shifted from a focus on hemodynamics to modification of maladaptive molecular processes. Accumulating evidence shows that molecular biomarkers of disease could provide a unique window into the pathophysiology of chronic HF, potentially improving our ability to predict adverse outcomes, provide novel drug targets, and even help gauge therapeutic efficacy. The more 'traditional' biomarkers such as cardiac troponin, natriuretic peptides, and C-reactive protein have been studied in large cohorts of patients with chronic HF and have relatively established clinical applications. In this Review, we summarize the properties, clinical data, and potential applications of some emerging biomarkers that could uniquely indicate the level of biomechanical stretch, inflammation, ventricular remodeling, myocardial injury, and renal dysfunction that occurs in chronic HF. We will also discuss the potential role for these biomarkers within a multimarker-based strategy that could, in the future, lead to better care for these patients.

Novel biomarkers in human terminal heart failure and under mechanical circulatory support

This review summarizes recent findings on novel biochemical plasma biomarkers in terminal heart failure patients, which might predict an advanced mortality risk or even recovery. Moreover, we discussed the regulation of these heart failure-related biomarkers under mechanical circulatory support.

Serial measurement of growth-differentiation factor-15 in heart failure: relation to disease severity and prognosis in the Valsartan Heart Failure Trial

BACKGROUND

Growth-differentiation factor-15 (GDF-15) is emerging as a prognostic biomarker in patients with coronary artery disease. Little is known about GDF-15 as a biomarker in patients with heart failure.

METHODS AND RESULTS

The circulating concentration of GDF-15 was measured at baseline (n=1734) and at 12 months (n=1517) in patients randomized in the Valsartan Heart Failure Trial (Val-HeFT). GDF-15 levels at baseline ranged from 259 to 25 637 ng/L and were abnormally high (>1200 ng/L) in 85% of patients. Higher levels were associated with features of worse heart failure and biomarkers of neurohormonal activation, inflammation, myocyte injury, and renal dysfunction. Baseline GDF-15 levels (per 100 ng/L) were associated with the risks of mortality (hazard ratio, 1.017; 95% confidence interval, 1.014 to 1.019; P<0.001) and first morbid event (hazard ratio, 1.020; 95% confidence interval, 1.017 to 1.023; P<0.001). In a comprehensive multiple-variable Cox regression model that included clinical prognostic variables, B-type natriuretic peptide, high-sensitivity C-reactive protein, and high-sensitivity troponin T, GDF-15 remained independently associated with mortality (hazard ratio, 1.007; 95% confidence interval, 1.001 to 1.014; P=0.02) but not first morbid event. At 12 months, the GDF-15 levels had increased by a similar amount in the placebo and valsartan groups (P=0.94). Increases in GDF-15 over 12 months were independently associated with the risks of future mortality and first morbid event also after adjustment for clinical prognostic variables, B-type natriuretic peptide, high-sensitivity C-reactive protein, and high-sensitivity troponin T and their changes.

CONCLUSIONS

GDF-15 reflects information from several pathological pathways and provides independent prognostic information in heart failure. GDF-15 levels increase over time, suggesting that GDF-15 reflects a pathophysiological axis that is not completely addressed by the therapies prescribed in Val-HeFT.

Growth differentiation factor-15: a new biomarker in cardiovascular disease

Growth differentiation factor-(GDF-)15 is a stress-responsive cytokine that is emerging as a biomarker of cardiac and vascular dysfunction and disease. Elevated circulating levels of GDF-15 identify high-risk individuals across the cardiovascular continuum, from stable coronary artery disease to acute coronary syndrome and heart failure. The association of GDF-15 with outcome in these conditions is independent of clinical risk factors and established biomarkers, including NT-proBNP (N-terminal pro-B-type natriuretic peptide) and troponin. The prognostic information provided by GDF-15 in cardiovascular disease may inform patient management, e.g., by identifying patients with non-ST segment elevation acute coronary syndrome who benefit from an invasive strategy, or by monitoring treatment response in heart failure. Future studies need to evaluate prospectively whether GDF-15, alone or as part of a multimarker strategy, can improve contemporary risk prediction algorithms and support therapeutic management of patients with cardiovascular disease.

The development of gene therapy for diseases of the lung

The development of a successful gene therapy has many stages, including preclinical testing in animal models and proof of principle clinical studies. A variety of diseases affect the lung, which are candidates for gene therapy; this review will mainly focus on the diseases that have attracted the most attention and have therefore yielded the most progress, namely lung cancer and the monogenic disorder cystic fibrosis. Knowledge gained from clinical studies could eventually be applied to more complex lung conditions such as acute respiratory distress syndrome and asthma. In addition, increased gene transfer efficiencies could be obtained by appropriate selection of the gene transfer vector and mode of delivery.