Relaxin for the treatment of patients with acute heart failure (Pre-RELAX-AHF): a multicentre, randomised, placebo-controlled, parallel-group, dose-finding phase IIb study

Relaxin suppresses atrial fibrillation, reverses fibrosis and reduces inflammation in aged hearts

Healthy aging results in cardiac structural and electrical remodeling that increase susceptibility to cardiovascular diseases. Relaxin has shown broad cardioprotective effects including anti-fibrotic, anti-arrhythmic and anti-inflammatory outcomes in multiple models. This paper focuses on the cardioprotective effects of Relaxin in a rat model of aging. Sustained atrial or ventricular fibrillation are readily induced in the hearts of aged but not young control animals. Treatment with Relaxin suppressed this arrhythmogenic response by increasing conduction velocity, decreasing fibrosis and promoting substantial cardiac remodeling. Relaxin treatment resulted in a significant increase in the levels of: Nav1.5, Cx43, βcatenin and Wnt1 in rat hearts. In isolated cardiomyocytes, Relaxin increased Nav1.5 expression. These effects were mimicked by CHIR 99021, a pharmacological activator of canonical Wnt signaling, but blocked by the canonical Wnt inhibitor Dickkopf1. Relaxin prevented TGF-β-dependent differentiation of cardiac fibroblasts into myofibroblasts while increasing the expression of Wnt1; the effects of Relaxin on cardiac fibroblast differentiation were blocked by Dickkopf1. RNASeq studies demonstrated reduced expression of pro-inflammatory cytokines and an increase in the expression of α- and β-globin in Relaxin-treated aged males. Relaxin reduces arrhythmogenicity in the hearts of aged rats by reduction of fibrosis and increased conduction velocity. These changes are accompanied by substantial remodeling of the cardiac tissue and appear to be mediated by increased canonical Wnt signaling. Relaxin also exerts significant anti-inflammatory and anti-oxidant effects in the hearts of aged rodents. The mechanisms by which Relaxin increases the expression of Wnt ligands, promotes Wnt signaling and reprograms gene expression remain to be determined.

Vasodilators for Acute Heart Failure - A Systematic Review with Meta-Analysis

BACKGROUND

Acute heart failure is a public health concern. This study systematically reviewed randomized clinical trials (RCTs) to evaluate vasodilators in acute heart failure.

METHODS

The search was conducted across the databases of Medline, Embase, Latin American and the Caribbean Literature on Health Sciences, Web of Science, and the Cochrane Central Register of Controlled Trials. Inclusion criteria consisted of RCTs that compared vasodilators versus standard care, placebo, or cointerventions. The primary outcome was all-cause mortality; secondary outcomes were serious adverse events (SAEs), tracheal intubation, and length of hospital stay. Risk of bias was assessed in all trials.

RESULTS

The study included 46 RCTs that enrolled 28,374 patients with acute heart failure. Vasodilators did not reduce the risk of all-cause mortality (risk ratio, 0.95; 95% confidence interval [CI], 0.87 to 1.04; I2=9.51%; P=0.26). No evidence of a difference was seen in the risk of SAEs (risk ratio, 1.01; 95% CI, 0.97 to 1.05; I2=0.94%) or length of hospital stay (mean difference, -0.10; 95% CI, -0.28 to 0.08; I2=69.84%). Vasodilator use was associated with a lower risk of tracheal intubation (risk ratio, 0.54; 95% CI, 0.30 to 0.99; I2=51.96%) compared with no receipt of vasodilators.

CONCLUSIONS

In this systematic review with meta-analysis of patients with acute heart failure, vasodilators did not reduce all-cause mortality.

Identification and Quantification of Human Relaxin Proteins by Immunoaffinity-Mass Spectrometry

The human relaxins belong to the Insulin/IGF/Relaxin superfamily of peptide hormones, and their physiological function is primarily associated with reproduction. In this study, we focused on a prostate tissue-specific relaxin RLN1 (REL1_HUMAN protein) and a broader tissue specificity RLN2 (REL2_HUMAN protein). Due to their structural similarity, REL1 and REL2 proteins were collectively named a 'human relaxin protein' in previous studies and were exclusively measured by immunoassays. We hypothesized that the highly selective and sensitive immunoaffinity-selected reaction monitoring (IA-SRM) assays would reveal the identity and abundance of the endogenous REL1 and REL2 in biological samples and facilitate the evaluation of these proteins for diagnostic applications. High levels of RLN1 and RLN2 transcripts were found in prostate and breast cancer cell lines by RT-PCR. However, no endogenous prorelaxin-1 or mature REL1 were detected by IA-SRM in cell lines, seminal plasma, or blood serum. The IA-SRM assay of REL2 demonstrated its undetectable levels (<9.4 pg/mL) in healthy control female and male sera and relatively high levels of REL2 in maternal sera across different gestational weeks (median 331 pg/mL; N = 120). IA-SRM assays uncovered potential cross-reactivity and nonspecific binding for relaxin immunoassays. The developed IA-SRM assays will facilitate the investigation of the physiological and pathological roles of REL1 and REL2 proteins.

The involvement of the Wnt/β-catenin signaling cascade in fibrosis progression and its therapeutic targeting by relaxin

Organ scarring, referred to as fibrosis, results from a failed wound-healing response to chronic tissue injury and is characterised by the aberrant accumulation of various extracellular matrix (ECM) components. Once established, fibrosis is recognised as a hallmark of stiffened and dysfunctional tissues, hence, various fibrosis-related diseases collectively contribute to high morbidity and mortality in developed countries. Despite this, these diseases are ineffectively treated by currently-available medications. The pro-fibrotic cytokine, transforming growth factor (TGF)-β1, has emerged as the master regulator of fibrosis progression, owing to its ability to promote various factors and processes that facilitate rapid ECM synthesis and deposition, whilst negating ECM degradation. TGF-β1 signal transduction is tightly controlled by canonical (Smad-dependent) and non-canonical (MAP kinase- and Rho-associated protein kinase-dependent) intracellular protein activity, whereas its pro-fibrotic actions can also be facilitated by the Wnt/β-catenin pathway. This review outlines the pathological sequence of events and contributing roles of TGF-β1 in the progression of fibrosis, and how the Wnt/β-catenin pathway contributes to tissue repair in acute disease settings, but to fibrosis and related tissue dysfunction in synergy with TGF-β1 in chronic diseases. It also outlines the anti-fibrotic and related signal transduction mechanisms of the hormone, relaxin, that are mediated via its negative modulation of TGF-β1 and Wnt/β-catenin signaling, but through the promotion of Wnt/β-catenin activity in acute disease settings. Collectively, this highlights that the crosstalk between TGF-β1 signal transduction and the Wnt/β-catenin cascade may provide a therapeutic target that can be exploited to broadly treat and reverse established fibrosis.

New Pharmacotherapeutic Classes for the Management of Heart Failure: A Narrative Review

Heart failure (HF) is a syndrome characterized by the heart failing to pump blood to the body at a rate proportional to its needs. HF is a public health burden globally and one of the leading causes of hospitalizations in adults. While many classes of drugs have been introduced for the treatment of HF, not every drug may be well-tolerated by patients. In this narrative review, we describe a few of the newer classes of medications proposed to be efficacious in treating acute and chronic HF. We focus on vericiguat, omecamtiv mecarbil, ularitide, and serelaxin, and thoroughly examine their efficacy and safety profiles while summarizing the clinical trials of the drugs. There is a need for more long-term studies comparing the efficacy of these medications to the conventional ones.

Impact of the MEESSI-AHF tool to guide disposition decision-making in patients with acute heart failure in the emergency department: a before-and-after study

OBJECTIVES

To determine the impact of risk stratification using the MEESSI-AHF (Multiple Estimation of risk based on the Emergency department Spanish Score In patients with acute heart failure) scale to guide disposition decision-making on the outcomes of ED patients with acute heart failure (AHF), and assess the adherence of emergency physicians to risk stratification recommendations.

METHODS

This was a prospective quasi-experimental study (before/after design) conducted in eight Spanish EDs which consecutively enrolled adult patients with AHF. In the pre-implementation stage, the admit/discharge decision was performed entirely based on emergency physician judgement. During the post-implementation phase, emergency physicians were advised to 'discharge' patients classified by the MEESSI-AHF scale as low risk and 'admit' patients classified as increased risk. Nonetheless, the final decision was left to treating emergency physicians. The primary outcome was 30-day all-cause mortality. Secondary outcomes were days alive and out of hospital, in-hospital mortality and 30-day post-discharge combined adverse event (ED revisit, hospitalisation or death).

RESULTS

The pre-implementation and post-implementation cohorts included 1589 and 1575 patients, respectively (median age 85 years, 56% females) with similar characteristics, and 30-day all-cause mortality was 9.4% and 9.7%, respectively (post-implementation HR=1.03, 95% CI=0.82 to 1.29). There were no differences in secondary outcomes or in the percentage of patients entirely managed in the ED without hospitalisation (direct discharge from the ED, 23.5% vs 24.4%, OR=1.05, 95% CI=0.89 to 1.24). Adjusted models did not change these results. Emergency physicians followed the MEESSI-AHF-based recommendation on patient disposition in 70.9% of cases (recommendation over-ruling: 29.1%). Physicians were more likely to over-rule the recommendation when 'discharge' was recommended (56.4%; main reason: need for hospitalisation for a second diagnosis) than when 'admit' was recommended (12.8%; main reason: no appreciation of severity of AHF decompensation by emergency physician), with an OR for over-ruling the 'discharge' compared with the 'admit' recommendation of 8.78 (95% CI=6.84 to 11.3).

CONCLUSIONS

Implementing the MEESSI-AHF risk stratification tool in the ED to guide disposition decision-making did not improve patient outcomes.

The role of relaxin in anterior cruciate ligament injuries: a systematic review

OBJECTIVE

Anterior cruciate ligament (ACL) tears are exceedingly common among the athletic population and are seen with higher incidence in females. Observational studies have noted peak ACL tear rates in the luteal phase of the menstrual cycle, a time in which the hormone relaxin peaks in serum concentration.

METHODS

A systematic review of the literature was performed. Inclusion criteria specified all prospective and retrospective studies which included the role of relaxin in the pathogenesis of ACL tears.

RESULTS

Six studies met inclusion criteria yielding 189 subjects from clinical studies and 51 in vitro samples. Included studies found that ACL samples exhibit selective relaxin binding. When pre-treated with estrogen prior to relaxin exposure, female ACL tissue samples exhibit increased expression of collagen degrading receptors.

CONCLUSION

Relaxin displays binding specificity to the female ACL and increased serum concentrations are correlated with increased ACL tear rates in female athletes. Further research is needed in this area.

LEVEL OF EVIDENCE

V.

Cardiovascular effects of relaxin-2: therapeutic potential and future perspectives

The hormone relaxin-2 has emerged as a promising player in regulating the physiology of the cardiovascular system. Through binding to the relaxin family peptide receptor 1 (RXFP1), this hormone elicits multiple physiological responses including vasodilation induction, reduction of inflammation and oxidative stress, and angiogenesis stimulation. The role of relaxin-2, or its recombinant human form known as serelaxin, has been investigated in preclinical and clinical studies as a potential therapy for cardiovascular diseases, especially heart failure, whose current therapy is still unoptimized. However, evidence from past clinical trials has been inconsistent and further research is needed to fully understand the potential applications of relaxin-2. This review provides an overview of serelaxin use in clinical trials and discusses future directions in the development of relaxin-2 mimetics, which may offer new therapeutic options for patients with heart failure.

Disconnect between the effects of serelaxin on renal function and outcome in acute heart failure

BACKGROUND

We aimed to study whether improvement in renal function by serelaxin in patients who were hospitalized for acute heart failure (HF) might explain any potential effect on clinical outcomes.

METHODS

We included 6318 patients from the RELAXin in AHF-2 (RELAX-AHF2) study. Improvement in renal function was defined as a decrease in serum creatinine of ≥ 0.3 mg/dL and ≥ 25%, or increase in estimated glomerular filtration rate of ≥ 25% between baseline and day 2. Worsening renal function (WRF) was defined as the reverse. We performed causal mediation analyses regarding 180-day all-cause mortality (ACM), cardiovascular death (CVD), and hospitalization for HF/renal failure.

RESULTS

Improvement in renal function was more frequently observed with serelaxin when compared with placebo [OR 1.88 (95% CI 1.64-2.15, p < 0.0001)], but was not associated with subsequent clinical outcomes. WRF occurred less frequent with serelaxin [OR 0.70 (95% CI 0.60-0.83, p < 0.0001)] and was associated with increased risk of ACM, worsening HF and the composite of CVD and HF or renal failure hospitalization. Improvement in renal function did not mediate the treatment effect of serelaxin [CVD HR 1.01 (0.99-1.04), ACM HR 1.01 (0.99-1.03), HF/renal failure hospitalization HR 0.99 (0.97-1.00)].

CONCLUSIONS

Despite the significant improvement in renal function by serelaxin in patients with acute HF, the potential beneficial treatment effect was not mediated by improvement in renal function. These data suggest that improvement in renal function might not be a suitable surrogate marker for potential treatment efficacy in future studies with novel relaxin agents in acute HF. Central illustration. Conceptual model explaining mediation analysis; treatment efficacy of heart failure therapies mediated by renal function.

Minimally invasive, sustained-release relaxin-2 microparticles reverse arthrofibrosis

Substantial advances in biotherapeutics are distinctly lacking for musculoskeletal diseases. Musculoskeletal diseases are biomechanically complex and localized, highlighting the need for novel therapies capable of addressing these issues. All frontline treatment options for arthrofibrosis, a debilitating musculoskeletal disease, fail to treat the disease etiology-the accumulation of fibrotic tissue within the joint space. For millions of patients each year, the lack of modern and effective treatment options necessitates surgery in an attempt to regain joint range of motion (ROM) and escape prolonged pain. Human relaxin-2 (RLX), an endogenous peptide hormone with antifibrotic and antifibrogenic activity, is a promising biotherapeutic candidate for musculoskeletal fibrosis. However, RLX has previously faltered through multiple clinical programs because of pharmacokinetic barriers. Here, we describe the design and in vitro characterization of a tailored drug delivery system for the sustained release of RLX. Drug-loaded, polymeric microparticles released RLX over a multiweek time frame without altering peptide structure or bioactivity. In vivo, intraarticular administration of microparticles in rats resulted in prolonged, localized concentrations of RLX with reduced systemic drug exposure. Furthermore, a single injection of RLX-loaded microparticles restored joint ROM and architecture in an atraumatic rat model of arthrofibrosis with clinically derived end points. Finally, confirmation of RLX receptor expression, RXFP1, in multiple human tissues relevant to arthrofibrosis suggests the clinical translational potential of RLX when administered in a sustained and targeted manner.

Efficacy of pharmacologic therapies in patients with acute heart failure: A network meta-analysis

Background: A network meta-analysis (NMA) of the current recommended drugs for the treatment of acute heart failure (AHF), was performed to compare the relative efficacy.

Methods: We used PubMed, EMBASE, Cochrane Clinical Trials Register, and Web of Science systems to search studies of randomized controlled trials (RCT) for the treatment of AHF recommended by the guidelines and expert consensus until 1 December 2020. The primary outcome was all-cause mortality within 30 days. The secondary outcomes included 30-days all-cause rehospitalization, rates of HF-related rehospitalization, rates of adverse events, and rates of serious adverse events. A Bayesian NMA based on random effects model was performed.

Results: After screening 14,888 citations, 23 RCTs (17,097 patients) were included, focusing on nesiritide, placebo, serelaxin, rhANP, omecamtiv mecarbil, tezosentan, KW-3902, conivaptan, tolvaptan, TRV027, chlorothiazide, metolazone, ularitide, relaxin, and rolofylline. Omecamtiv mecarbil had significantly lower all-cause mortality rates than the placebo (odds ratio 0.04, 0.01–0.22), rhANP (odds ratio 0.03, 0–0.40), serelaxin (odds ratio 0.05, 0.01–0.38), tezosentan (odds ratio 0.04, 0–0.22), tolvaptan (odds ratio 0.04, 0.01–0.30), and TRV027 (odds ratio 0.03, 0–0.36). No drug was superior to the other drugs for the secondary outcomes and safety outcomes.

Conclusion: No drug was superior to the other drugs for the secondary outcomes and safety outcomes. Current drugs for AHF show similar efficacy and safety.

The interstitial compartment as a therapeutic target in heart failure

Congestion is the single most important contributor to heart failure (HF) decompensation. Most of the excess volume in patients with HF resides in the interstitial compartment. Inadequate decongestion implies persistent interstitial congestion and is associated with worse outcomes. Therefore, effective interstitial decongestion represents an unmet need to improve quality of life and reduce clinical events. The key processes that underlie incomplete interstitial decongestion are often ignored. In this review, we provide a summary of the pathophysiology of the interstitial compartment in HF and the factors governing the movement of fluids between the interstitial and vascular compartments. Disruption of the extracellular matrix compaction occurs with edema, such that the interstitium becomes highly compliant, and large changes in volume marginally increase interstitial pressure and allow progressive capillary filtration into the interstitium. Augmentation of lymph flow is required to prevent interstitial edema, and the lymphatic system can increase fluid removal by at least 10-fold. In HF, lymphatic remodeling can become insufficient or maladaptive such that the capacity of the lymphatic system to remove fluid from the interstitium is exceeded. Increased central venous pressure at the site of the thoracic duct outlet also impairs lymphatic drainage. Owing to the kinetics of extracellular fluid, microvascular absorption tends to be transient (as determined by the revised Starling equation). Therefore, effective interstitial decongestion with adequate transcapillary plasma refill requires a substantial reduction in plasma volume and capillary pressure that are prolonged and sustained, which is not always achieved in clinical practice. The critical importance of the interstitium in the congestive state underscores the need to directly decongest the interstitial compartment without relying on the lowering of intracapillary pressure with diuretics. This unmet need may be addressed by novel device therapies in the near future.

Neutrophil-to-Lymphocyte Ratio and Outcomes in Patients Admitted for Acute Heart Failure (As Seen in the BLAST-AHF, Pre-RELAX-AHF, and RELAX-AHF Studies)

Previous studies have suggested that the neutrophil-to-lymphocyte ratio (NLR) is a novel yet readily evaluable inflammatory biomarker that may be useful for determining cardiovascular prognosis during acute episodes. The study investigated the role of NLR in predicting cardiovascular (CV) outcomes in patients with acute heart failure (HF). Individual patient data from the BLAST-AHF (phase 2b study of the biased ligand of the angiotensin 2 type 1 receptor, TRV027), Pre-RELAX-AHF (phase 2b study of recombinant human relaxin-2, serelaxin), and RELAX-AHF (phase 3 study of serelaxin) randomized, placebo-controlled studies for patients with acute HF were pooled for analysis. Dyspnea visual analog scale area under the curve through day 5, worsening HF through day 5, 30-day all-cause mortality, 60-day HF/renal failure rehospitalizations or CV death, 180-day all-cause mortality, and 180-day CV death were assessed. There were several differences in the baseline characteristics of the patients divided by NLR tertile, with patients in the higher NLR having worse clinical characteristics. NLR was an independent predictor of 30-day all-cause mortality (adjusted hazard ratio [HR] per log₂ NLR increment: 1.66 [1.22 to 2.25], p = 0.001), 60-day HF/renal failure rehospitalizations or CV death: 1.33 [1.12 to 1.57], p = 0.001), 180-day all-cause mortality (adjusted HR 1.27 [1.08 to 1.50], p = 0.003), and 180-day CV death (adjusted HR 1.24 [1.04 to 1.49], p = 0.018). NLR, a readily available inflammatory biomarker, was associated with independent risk for short- and long-term adverse outcomes in acute HF, surpassing traditional markers, such as natriuretic peptides.

Relaxin-2 as a Potential Biomarker in Cardiovascular Diseases

The pleiotropic hormone relaxin-2 plays a pivotal role in the physiology and pathology of the cardiovascular system. Relaxin-2 exerts relevant regulatory functions in cardiovascular tissues through the specific receptor relaxin family peptide receptor 1 (RXFP1) in the regulation of cardiac metabolism; the induction of vasodilatation; the reversion of fibrosis and hypertrophy; the reduction of inflammation, oxidative stress, and apoptosis; and the stimulation of angiogenesis, with inotropic and chronotropic effects as well. Recent preclinical and clinical outcomes have encouraged the potential use of relaxin-2 (or its recombinant form, known as serelaxin) as a therapeutic strategy during cardiac injury and/or in patients suffering from different cardiovascular disarrangements, especially heart failure. Furthermore, relaxin-2 has been proposed as a promising biomarker of cardiovascular health and disease. In this review, we emphasize the relevance of the endogenous hormone relaxin-2 as a useful diagnostic biomarker in different backgrounds of cardiovascular pathology, such as heart failure, atrial fibrillation, myocardial infarction, ischemic heart disease, aortic valve disease, hypertension, and atherosclerosis, which could be relevant in daily clinical practice and could contribute to comprehending the specific role of relaxin-2 in cardiovascular diseases.

Efficacy of Nondiuretic Pharmacotherapy for Improving the Treatment of Congestion in Patients with Acute Heart Failure: A Systematic Review of Randomised Controlled Trials

Diuretic therapy is the mainstay during episodes of acute heart failure (AHF). Diuretic resistance is often encountered and poses a substantial challenge for clinicians. There is a lack of evidence on the optimal strategies to tackle this problem. This review aimed to compare the outcomes associated with congestion management based on a strategy of pharmacological nondiuretic-based regimens. The PubMed, Cochrane Library, Scopus, and ScienceDirect databases were systematically searched for all randomised controlled trials (RCTs) of adjuvant pharmacological treatments used during hospitalisation episodes of AHF patients. Congestion relief constitutes the main target in AHF; hence, only studies with efficacy indicators related to decongestion enhancement were included. The Cochrane risk-of-bias tool was used to evaluate the methodological quality of the included RCTs. Twenty-three studies were included; dyspnea relief constituted the critical efficacy endpoint in most included studies. However, substantial variations in dyspnea measurement were found. Tolvaptan and serelaxin were found to be promising options that might improve decongestion in AHF patients. However, further high-quality RCTs using a standardised approach to diuretic management, including dosing and monitoring strategies, are crucial to provide new insights and recommendations for managing heart failure in acute settings.

Relaxin/serelaxin for cardiac dysfunction and heart failure in hypertension

The pregnancy related hormone relaxin is produced throughout the reproductive system. However, relaxin also has important cardiovascular effects as part of the adaptation that the cardiovascular system undergoes in response to the extra demands of pregnancy. These effects are primarily mediated by the relaxin family peptide receptor 1, which is one of four known relaxin receptors. The effects of relaxin on the cardiovascular system during pregnancy, as well as its anti-fibrotic and anti-inflammatory properties, have led to extensive studies into the potential of relaxin therapy as an approach to treat heart failure. Cardiomyocytes, cardiac fibroblasts, and endothelial cells all possess relaxin family peptide receptor 1, allowing for direct effects of therapeutic relaxin on the heart. Many pre-clinical animal studies have demonstrated a beneficial effect of exogenous relaxin on adverse cardiac remodeling including inflammation, fibrosis, cardiomyocyte hypertrophy and apoptosis, as well as effects on cardiac contractile function. Despite this, clinical studies have yielded disappointing results for the synthetic seralaxin, even though seralaxin was well tolerated. This article will provide background on relaxin in the context of normal physiology, as well as the role of relaxin in pregnancy-related adaptations of the cardiovascular system. We will also present evidence from pre-clinical animal studies that demonstrate the potential benefits of relaxin therapy, as well as discussing the results from clinical trials. Finally, we will discuss possible reasons for the failure of these clinical trials as well as steps being taken to potentially improve relaxin therapy for heart failure.

Insights of Worsening Renal Function in Type 1 Cardiorenal Syndrome: From the Pathogenesis, Biomarkers to Treatment

Type-1 cardiorenal syndrome refers to acute kidney injury induced by acute worsening cardiac function. Worsening renal function is a strong and independent predictive factor for poor prognosis. Currently, several problems of the type-1 cardiorenal syndrome have not been fully elucidated. The pathogenesis mechanism of renal dysfunction is unclear. Besides, the diagnostic efficiency, sensitivity, and specificity of the existing biomarkers are doubtful. Furthermore, the renal safety of the therapeutic strategies for acute heart failure (AHF) is still ambiguous. Based on these issues, we systematically summarized and depicted the research actualities and predicaments of the pathogenesis, diagnostic markers, and therapeutic strategies of worsening renal function in type-1 cardiorenal syndrome.

New Perspectives in the Treatment of Acute and Chronic Heart Failure with Reduced Ejection Fraction

Acute and chronic heart failure with reduced ejection fraction (HFrEF) is a major public health problem, studies showing a 25% survival rate at 5 years after hospitalization. If left untreated, it is a common and potentially fatal disease. In recent years, the medical and device therapies of patients with HFrEF have significantly improved. The aim of our review is to provide an evidence-based update on new therapeutic strategies in acute and chronic settings, to prevent hospitalization and death in patients with HFrEF. We performed a systematic literature search on PubMed, EMBASE, and the Cochrane Database of Systemic Reviews, and we included a number of 23 randomized controlled trials published in the last 30 years. The benefit of beta-blockers and renin-angiotensin-aldosterone system inhibitors in patients with HFrEF is well known. Recent developments, such as sodium-glucose cotransporter 2 inhibitors, vericiguat, transcatheter mitral valve repair, wireless pulmonary artery pressure monitor and cardiac contractility modulation, have also proven effective in improving prognosis. In addition, other new therapeutic agents showed encouraging results, but they are currently being studied. The implementation of personalized disease management programs that directly target the cause of HFrEF is crucial in order to improve prognosis and quality of life for these patients.

Relaxin as an anti-fibrotic treatment: Perspectives, challenges and future directions

Fibrosis refers to the scarring and hardening of tissues, which results from a failed immune system-coordinated wound healing response to chronic organ injury and which manifests from the aberrant accumulation of various extracellular matrix components (ECM), primarily collagen. Despite being a hallmark of prolonged tissue damage and related dysfunction, and commonly associated with high morbidity and mortality, there are currently no effective cures for its regression. An emerging therapy that meets several criteria of an effective anti-fibrotic treatment, is the recombinant drug-based form of the human hormone, relaxin (also referred to as serelaxin, which is bioactive in several other species). This review outlines the broad anti-fibrotic and related organ-protective roles of relaxin, mainly from studies conducted in preclinical models of ageing and fibrotic disease, including its ability to ameliorate several aspects of fibrosis progression and maturation, from immune cell infiltration, pro-inflammatory and pro-fibrotic cytokine secretion, oxidative stress, organ hypertrophy, cell apoptosis, myofibroblast differentiation and ECM production, to its ability to facilitate established ECM degradation. Studies that have compared and/or combined these therapeutic effects of relaxin with current standard of care medication have also been discussed, along with the main challenges that have hindered the translation of the anti-fibrotic efficacy of relaxin to the clinic. The review then outlines the future directions as to where scientists and several pharmaceutical companies that have recognized the therapeutic potential of relaxin are working towards, to progress its development as a treatment for human patients suffering from various fibrotic diseases.

Practical Recommendations on Quantifying and Interpreting Treatment Effects in the Presence of Terminal Competing Risks: A Review

Importance

In a comparative trial, the time to a clinical event is often a key end point. However, the occurrence of a terminal event, such as death or premature study discontinuation, may preclude observation of this outcome. Although various methods for handling competing risks are available, no specific recommendations have been made for scenarios encountered in practice, especially when the terminal event profiles of the study arms are dissimilar. Moreover, appropriate methods for a desirable outcome, such as live hospital discharge, have seldom been discussed.

Observations

Several of the most commonly used methods are reviewed. The first regards the terminal event as censoring and applies standard survival analysis to the event of interest. The between-group difference is usually summarized by the cause-specific hazard ratio. This summary measure is inappropriate when the new therapy markedly prolongs time to the terminal event. Moreover, the corresponding Kaplan-Meier curve for the end point of interest is uninterpretable. The second method is to use the cumulative incidence curve, which is the probability of experiencing the event of interest by each time point, acknowledging that patients who have died will never experience the event. However, the resulting pseudo hazard ratio is difficult to interpret. With a proper alternative summary measure, this approach works well for a desirable outcome but may not for an undesirable outcome. The third method focuses on the event-free survival time by combining information from occurrences of the terminal event and the event of interest simultaneously. This clinically interpretable method naturally accounts for differences in terminal event rates when comparing treatments with respect to the time to an undesirable outcome.

Conclusions and Relevance

This article enhances our understanding of each method's advantages and shortcomings and assists practitioners in choosing appropriate methods for handling competing risk problems in practice.

Dyspnea Measurement in Acute Heart Failure: A Systematic Review and Evidence Map of Randomized Controlled Trials

Background: Dyspnea is the most common presenting symptom among patients hospitalized for acute heart failure (AHF). Dyspnea relief constitutes a clinically relevant therapeutic target and endpoint for clinical trials and regulatory approval. However, there have been no widely accepted dyspnea measurement standards in AHF. By systematic review and mapping the current evidence of the applied scales, timing, and results of measurement, we hope to provide some new insights and recommendations for dyspnea measurement. Methods: PubMed, Embase, Cochrane Library, and Web of Science were searched from inception until August 27, 2020. Randomized controlled trials (RCTs) with dyspnea severity measured as the endpoint in patients with AHF were included. Results: Out of a total of 63 studies, 28 had dyspnea as the primary endpoint. The Likert scale (34, 54%) and visual analog scale (VAS) (22, 35%) were most widely used for dyspnea assessment. Among the 43 studies with detailed results, dyspnea was assessed most frequently on days 1, 2, 3, and 6 h after randomization or drug administration. Compared with control groups, better dyspnea relief was observed in the experimental groups in 21 studies. Only four studies that assessed tolvaptan compared with control on the proportion of dyspnea improvement met the criteria for meta-analyses, which did not indicate beneficial effect of dyspnea improvement on day 1 (RR: 1.16; 95% CI: 0.99-1.37; p = 0.07; I ² = 61%). Conclusion: The applied scales, analytical approaches, and timing of measurement are in diversity, which has impeded the comprehensive evaluation of clinical efficacy of potential therapies managing dyspnea in patients with AHF. Developing a more general measurement tool established on the unified unidimensional scales, standardized operation protocol to record the continuation, and clinically significant difference of dyspnea variation may be a promising approach. In addition, to evaluate the effect of experimental therapies on dyspnea more precisely, the screening time and blinded assessment are factors that need to be considered.

[Update on diagnostics and treatment of heart failure]

Inzidenz und Prävalenz der Herzinsuffizienz steigen weltweit. Trotz zahlreicher wissenschaftlicher und klinischer Innovationen ist sie weiterhin mit einer hohen Morbidität und Mortalität behaftet, sodass eine leitliniengerechte Diagnostik und Therapie von entscheidender Bedeutung sind. Die kardiale Dekompensation zählt zu den häufigsten Aufnahmegründen in deutschen Krankenhäusern. Somit stellt die Behandlung herzinsuffizienter Patienten eine erhebliche Herausforderung für das deutsche Gesundheitssystem dar. Dieser Artikel fasst die neuesten wissenschaftlichen Erkenntnisse zur akuten und chronischen Herzinsuffizienz der Jahre 2018 bis 2020 zusammen.

Relaxin and the Cardiovascular System: from Basic Science to Clinical Practice

The peptide hormone relaxin was originally linked to reproductive physiology, where it is believed to mediate systemic and renal hemodynamic adjustments to pregnancy. Recently, its broad range of effects in the cardiovascular system has been the focus of intensive research regarding its implications under pathological conditions and potential therapeutic potential. An understanding of the multitude of cardioprotective actions prompted the study of serelaxin, recombinant human relaxin-2, for the treatment of acute heart failure. Despite early promising results from phase II studies, recently revealed RELAX-AHF-2 outcomes were rather disappointing and the treatment for acute heart failure remains an unmet medical need. This article reviews the physiologic actions of relaxin on the cardiovascular system and its relevance in the pathophysiology of cardiovascular disease. We summarize the most updated clinical data and discuss future directions of serelaxin for the treatment of acute heart failure. This should encourage additional work to determine how can relaxin's beneficial effects be exploited for the treatment of cardiovascular disease.

Cardiac fibrosis: Myofibroblast-mediated pathological regulation and drug delivery strategies

Cardiac fibrosis remains an unresolved problem in heart diseases. After initial injury, cardiac fibroblasts (CFs) are activated and subsequently differentiate into myofibroblasts (myoFbs) that are major mediator cells in the pathological remodeling. MyoFbs exhibit proliferative and secretive characteristics, and contribute to extracellular matrix (ECM) turnover, collagen deposition. The persistent functions of myoFbs lead to fibrotic scars and cardiac dysfunction. The anti-fibrotic treatment is hindered by the elusive mechanism of fibrosis and lack of specific targets on myoFbs. In this review, we will outline the progress of cardiac fibrosis and its contributions to the heart failure. We will also shed light on the role of myoFbs in the regulation of adverse remodeling. The communication between myoFbs and other cells that are involved in the heart injury and repair respectively will be reviewed in detail. Then, recently developed therapeutic strategies to treat fibrosis will be summarized such as i) chimeric antigen receptor T cell (CAR-T) therapy with an optimal target on myoFbs, ii) direct reprogramming from stem cells to quiescent CFs, iii) "off-target" small molecular drugs. The application of nano/micro technology will be discussed as well, which is involved in the construction of cell-based biomimic platforms and "pleiotropic" drug delivery systems.

The levels of relaxin and amino acids play a critical role in women with variable degree of preparedness for labour

Underlying biochemical factors that contribute towards the preparedness for labour and ripening of the cervix remain largely unknown. We aimed to characterize metabolic and hormonal determinants that constitute the preparedness for labour in women. The aim of the research was to study the content of relaxin and amino acids involved in its formation in primiparous pregnant women with various degrees of birth preparedness. Materials and methods: Prospective study has been conducted on 115 primiparous women at 38-40 weeks of gestation. Biochemical methods were used to analyse relaxin and amino acid levels in pregnant women with varying degree of birth preparedness. Results: the obtained data from the study indicate importance role of relaxin in the underlying pathogenesis in women with variable degree of preparedness for labour. The results allow to use the levels of relaxin serum as a predictor of the state of the birth canal. Furthermore, the amino acids are known to participate in various critical metabolic processes and play an important role is orchestrating many essential pathways in the body. We present the analysis of amino acids involved in the formation of relaxin in the serum of pregnant women. Our analysis has shown that amino acid imbalance leads to disruption of energy metabolism and blood flow rate, resulting in metabolic, structural and functional changes in the cervix at the onset of labour. Conclusion: considering the mechanisms of the possible influence of relaxin and amino acids on the cervical ripening, we concluded that correcting amino acid imbalance and normalising relaxin levels should be included in preinduction of labour therapeutic regimen. This would be an important step in improving the perinatal outcomes

Human Recombinant Relaxin (Serelaxin) as Anti-fibrotic Agent: Pharmacology, Limitations and Actual Perspectives

Relaxin (recombinant human relaxin-2 hormone; RLX-2; serelaxin) had raised expectations as a new medication for fibrotic diseases. A plethora of in vitro and in vivo studies have offered convincing demonstrations that relaxin promotes remodelling of connective tissue extracellular matrix mediated by inhibition of multiple fibrogenic pathways, especially the downstream signalling of transforming growth factor (TGF)-β1, a major pro-fibrotic cytokine, and the recruitment and activation of myofibroblast, the main fibrosis-generating cells. However, all clinical trials with relaxin in patients with fibrotic diseases gave inconclusive results. In this review, we have summarized the molecular mechanisms of fibrosis, highlighting those which can be effectively targeted by relaxin. Then, we have performed a critical reappraisal of the clinical trials performed to-date with relaxin as anti-fibrotic drug, in order to highlight their key points of strength and weakness and to identify some future opportunities for the therapeutic use of relaxin, or its analogues, in fibrotic diseases and pathologic scarring which, in our opinion, deserve to be investigated.

Apelin ameliorated acute heart failure via inhibiting endoplasmic reticulum stress in rabbits

This study aimed to investigate whether inhibition of endoplasmic reticulum stress (ERS) mediated the ameliorative effect of apelin on acute heart failure (AHF). Rabbit model of AHF was induced by sodium pentobarbital. Cardiac dysfunction and injury were detected in the rabbit models of AHF, including impaired hemodynamic parameters and increased levels of CK-MB and cTnI. Apelin treatment dramatically improved cardiac impairment caused by AHF. ERS, indexed by increased GRP78, CHOP, and cleaved-caspase12 protein levels, was simultaneously attenuated by apelin. Apelin also could ameliorate increased protein levels of cleaved-caspase3 and Bax, and improved decreased protein levels of Bcl-2. Two common ERS stimulators, tunicamycin (Tm) and dithiothreitol (DTT) blocked the ameliorative effect of apelin on AHF. Phosphorylated Akt levels increased after apelin treatment in the rabbit models of AHF. The Akt signaling inhibitors wortmannin and LY294002 could block the cardioprotective effect of apelin, which could be relieved by ERS inhibitor 4-phenyl butyric acid (4-PBA). The aforementioned beneficial effects of apelin could all be blocked by APJ receptor antagonist F13A. 4-PBA and SC79, an Akt activator, can restore the ameliorative effect of apelin on AHF blocked by F13A. Apelin treatment dramatically ameliorated cardiac impairment caused by AHF, which might be mediated by APJ/Akt/ERS signaling pathway. These results will shed new light on AHF therapy.

Blood Pressure Reduction in Hypertensive Acute Heart Failure

PURPOSE OF REVIEW

To review the key clinical and research questions regarding blood pressure (BP) reduction with vasodilators in the early management of hypertensive acute heart failure (H-AHF).

RECENT FINDINGS

Despite numerous AHF vasodilator clinical trials in the past two decades, virtually none has studied a population where vasoconstriction is the predominant physiology, and with the agents and doses most commonly used in contemporary practice. AHF patients are remarkably heterogenous by vascular tone, and this heterogeneity is not always discernible through BP or clinical exam. Emerging data suggest that diastolic BP may be a stronger correlate of vascular tone in AHF than systolic BP, despite the latter historically serving as a key inclusion criterion for vasodilator clinical trials. Existing data are limited. A clinical trial that evaluates vasodilators in a manner of use consistent with contemporary practice, specifically within the subpopulation of patients with true H-AHF, is greatly needed. Until then, observational data supports long-standing vasodilators such as nitroglycerin, administered by IV bolus, and with goal reduction of SBP ≤25% as a safe first-line approach for patients with severe H-AHF presentations.

Relaxin abrogates genomic remodeling of the aged heart

"Healthy" aging drives structural and functional changes in the heart including maladaptive electrical remodeling, fibrosis and inflammation, which lower the threshold for cardiovascular diseases such as heart failure (HF) and atrial fibrillation (AF). Despite mixed results in clinical trials, Relaxin-therapy for 2-days reduced mortality by 37% at 180-days post-treatment, in patients with acute decompensated HF. Relaxin's short lifespan (2-3h) but long-lasting protective actions suggested that relaxin acts at a genomic level to reverse maladaptive remodeling in AF, HF and aging. Our recent studies showed that a 2-week treatment with Relaxin (0.4mg/kg/day) of aged (24months old F-344 rats) increases the expression of voltage-gated Na⁺ channels (mRNA, Nav1.5 and I_Na), connexin-43, abrogates inflammatory and immune responses and reverses myocardial fibrosis and cellular hypertrophy of the aged hearts. Relaxin acts directly at a wide range of cell types in the cardiovascular system that express its cognate GPCR receptor, RXFP1. RNA-seq analysis of young and aged hearts with and without Relaxin treatment revealed that "normal" aging altered the expression of ~10% of genes expressed in the ventricles, including: ion channels, components of fibrosis, hemodynamic biomarkers, immune and inflammatory responses which were reversed by Relaxin. The extensive cardiovascular remodeling caused by Relaxin was mediated through the activation of the Wnt/β-catenin signaling pathway which was otherwise suppressed by in adult cardiomyocytes intracellular by cytosolic Dickkopf1 (Dkk1). Wnt/β-catenin signaling is a mechanism that can explain the pleiotropic actions of Relaxin and the marked reversal of genomic changes that occur in aged hearts.

An Academic Clinician's Road Map to Hypertension Genomics: Recent Advances and Future Directions MMXX

At the dawn of the new decade, it is judicious to reflect on the boom of knowledge about polygenic risk for essential hypertension supplied by the wealth of genome-wide association studies. Hypertension continues to account for significant cardiovascular morbidity and mortality, with increasing prevalence anticipated. Here, we overview recent advances in the use of big data to understand polygenic hypertension, as well as opportunities for future innovation to translate this windfall of knowledge into clinical benefit.

Graphical approaches for the control of generalized error rates

When simultaneously testing multiple hypotheses, the usual approach in the context of confirmatory clinical trials is to control the familywise error rate (FWER), which bounds the probability of making at least one false rejection. In many trial settings, these hypotheses will additionally have a hierarchical structure that reflects the relative importance and links between different clinical objectives. The graphical approach of Bretz et al (2009) is a flexible and easily communicable way of controlling the FWER while respecting complex trial objectives and multiple structured hypotheses. However, the FWER can be a very stringent criterion that leads to procedures with low power, and may not be appropriate in exploratory trial settings. This motivates controlling generalized error rates, particularly when the number of hypotheses tested is no longer small. We consider the generalized familywise error rate (k-FWER), which is the probability of making k or more false rejections, as well as the tail probability of the false discovery proportion (FDP), which is the probability that the proportion of false rejections is greater than some threshold. We also consider asymptotic control of the false discovery rate, which is the expectation of the FDP. In this article, we show how to control these generalized error rates when using the graphical approach and its extensions. We demonstrate the utility of the resulting graphical procedures on three clinical trial case studies.

H3 relaxin protects against calcium oxalate crystal-induced renal inflammatory pyroptosis

OBJECTIVES

Calcium oxalate (CaOx) crystals can activate inflammatory cytokines by triggering inflammasomes, which cause damage to the adhered epithelium, a dysfunctional microenvironment and even renal failure. However, a comprehensive and in-depth understanding of the mechanisms underlying the effects of these crystals on damage and cytokine function in renal tubular epithelial cells (TECs) remains limited and to be explored.

MATERIALS AND METHODS

We detected the pyroptosis of TECs induced after exposure to CaOx crystals and demonstrated the significance of cytokine activation in the subsequent inflammatory processes through a proteomic study. We then conducted animal and cell experiments to verify relevant mechanisms through morphological, protein, histological and biochemical approaches. Human serum samples were further tested to help explain the pathophysiological mechanism of H3 relaxin.

RESULTS

We verified that crystal-induced extracellular adenosine triphosphate (ATP) upregulation via the membrane purinergic 2X₇ receptor (P2X₇ R) promotes ROS generation and thereby activates NLRP3 inflammasome-mediated interleukin-1β/18 maturation and gasdermin D cleavage. Human recombinant relaxin-3 (H3 relaxin) can act on the transmembrane receptor RXFP1 to produce cAMP and subsequently improves crystal-derived damage via ATP consumption. Additionally, endogenous relaxin-3 was found to be elevated in patients with renal calculus and can thus serve as a biomarker.

CONCLUSIONS

Our results provide previously unidentified mechanistic insights into CaOx crystal-induced inflammatory pyroptotic damage and H3 relaxin-mediated anti-inflammatory protection and thus suggest a series of potential therapeutic targets and methods for but not limited to nephrocalcinosis.

Recombinant human H2 relaxin (serelaxin) as a cardiovascular drug: aiming at the right target

Serelaxin (recombinant human relaxin-2 hormone; RLX-2) had raised expectations as a new medication for cardiovascular diseases. Evidence from preclinical studies indicated that serelaxin has chronotropic, inotropic, and anti-arrhythmic actions on the myocardium and cardioprotective effects mediated by vasodilation, angiogenesis, and inhibition of inflammation and fibrosis. However, clinical trials with serelaxin in patients with acute heart failure (AHF) gave inconclusive results. A critical reappraisal of the comprehensive cardiovascular actions of serelaxin clearly delineates acute myocardial infarction (AMI) as a feasible therapeutic target. Serelaxin acts at multiple levels on the pathogenic mechanisms of AMI and previous in vivo studies suggest that its administration at reperfusion affords myocardial salvage. Thus, serelaxin could be an effective adjunctive medical therapy to coronary angioplasty.

Mega-trials in heart failure: effects of dilution in examination of new therapies

AIMS

Over the last 30 years, many medicine development programmes in acute and chronic heart failure (HF) with preserved ejection fraction (HFpEF) have failed, in contrast to those in HF with reduced ejection fraction (HFrEF). We explore how the neutral results in larger HF trials may be attributable to chance and/or the dilution of statistical power.

METHODS AND RESULTS

Using simulations, we examined the probability that a positive finding in a Phase 2 trial would result in the study of a truly effective medicine in a Phase 3 trial. We assessed the similarity of clinical trial and registry patient populations. We conducted a meta-analysis of paired Phase 2 and 3 trials in HFrEF and acute HF examining the associations of trial phase and size with placebo event rates and treatment effects for HF events and death. We estimated loss in trial power attributable to dilution with increasing trial size. Appropriately powered Phase 3 trials should have yielded ∼35% positive results. Patient populations in Phase 3 trials are similar to those in Phase 2 trials but both differ substantially from the populations of 'real-life' registries. We observed decreasing placebo event rates and smaller treatment effects with increasing trial size, especially for HF events (and less so for mortality). This was more pronounced in trials in acute HF patients.

CONCLUSIONS

The selection of more positive Phase 2 trials for further development does not explain the failure of HFpEF and acute HF medicine development. Increasing sample size may lead to reduced event rates and smaller treatment effects, resulting in a high rate of neutral Phase 3 trials.

Altered Cerebral Blood Flow and Potential Neuroprotective Effect of Human Relaxin-2 (Serelaxin) During Hypoxia or Severe Hypovolemia in a Sheep Model

Specific neuroprotective strategies to minimize cerebral damage caused by severe hypoxia or hypovolemia are lacking. Based on previous studies showing that relaxin-2/serelaxin increases cortical cerebral blood flow, we postulated that serelaxin might provide a neuroprotective effect. Therefore, we tested serelaxin in two emergency models: hypoxia was induced via inhalation of 5% oxygen and 95% nitrogen for 12 min; thereafter, the animals were reoxygenated. Hypovolemia was induced and maintained for 20 min by removal of 50% of the total blood volume; thereafter, the animals were retransfused. In each damage model, the serelaxin group received an intravenous injection of 30 µg/kg of serelaxin in saline, while control animals received saline only. Blood gases, shock index values, heart frequency, blood pressure, and renal blood flow showed almost no significant differences between control and treatment groups in both settings. However, serelaxin significantly blunted the increase of lactate during hypovolemia. Serelaxin treatment resulted in significantly elevated cortical cerebral blood flow (CBF) in both damage models, compared with the respective control groups. Measurements of the neuroproteins S100B and neuron-specific enolase in cerebrospinal fluid revealed a neuroprotective effect of serelaxin treatment in both hypoxic and hypovolemic animals, whereas in control animals, neuroproteins increased during the experiment. Western blotting showed the expression of relaxin receptors and indicated region-specific differences in relaxin receptor-mediated signaling in cortical and subcortical brain arterioles, respectively. Our findings support the hypothesis that serelaxin is a potential neuroprotectant during hypoxia and hypovolemia. Due to its preferential improvement of cortical CBF, serelaxin might reduce cognitive impairments associated with these emergencies.

Pharmacological interventions for heart failure in people with chronic kidney disease

BACKGROUND

Approximately half of people with heart failure have chronic kidney disease (CKD). Pharmacological interventions for heart failure in people with CKD have the potential to reduce death (any cause) or hospitalisations for decompensated heart failure. However, these interventions are of uncertain benefit and may increase the risk of harm, such as hypotension and electrolyte abnormalities, in those with CKD.

OBJECTIVES

This review aims to look at the benefits and harms of pharmacological interventions for HF (i.e., antihypertensive agents, inotropes, and agents that may improve the heart performance indirectly) in people with HF and CKD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies through 12 September 2019 in consultation with an Information Specialist and using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials of any pharmacological intervention for acute or chronic heart failure, among people of any age with chronic kidney disease of at least three months duration.

DATA COLLECTION AND ANALYSIS

Two authors independently screened the records to identify eligible studies and extracted data on the following dichotomous outcomes: death, hospitalisations, worsening heart failure, worsening kidney function, hyperkalaemia, and hypotension. We used random effects meta-analysis to estimate treatment effects, which we expressed as a risk ratio (RR) with 95% confidence intervals (CI). We assessed the risk of bias using the Cochrane tool. We applied the GRADE methodology to rate the certainty of evidence.

MAIN RESULTS

One hundred and twelve studies met our selection criteria: 15 were studies of adults with CKD; 16 studies were conducted in the general population but provided subgroup data for people with CKD; and 81 studies included individuals with CKD, however, data for this subgroup were not provided. The risk of bias in all 112 studies was frequently high or unclear. Of the 31 studies (23,762 participants) with data on CKD patients, follow-up ranged from three months to five years, and study size ranged from 16 to 2916 participants. In total, 26 studies (19,612 participants) reported disaggregated and extractable data on at least one outcome of interest for our review and were included in our meta-analyses. In acute heart failure, the effects of adenosine A1-receptor antagonists, dopamine, nesiritide, or serelaxin on death, hospitalisations, worsening heart failure or kidney function, hyperkalaemia, hypotension or quality of life were uncertain due to sparse data or were not reported. In chronic heart failure, the effects of angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB) (4 studies, 5003 participants: RR 0.85, 95% CI 0.70 to 1.02; I² = 78%; low certainty evidence), aldosterone antagonists (2 studies, 34 participants: RR 0.61 95% CI 0.06 to 6.59; very low certainty evidence), and vasopressin receptor antagonists (RR 1.26, 95% CI 0.55 to 2.89; 2 studies, 1840 participants; low certainty evidence) on death (any cause) were uncertain. Treatment with beta-blockers may reduce the risk of death (any cause) (4 studies, 3136 participants: RR 0.69, 95% CI 0.60 to 0.79; I² = 0%; moderate certainty evidence). Treatment with ACEi or ARB (2 studies, 1368 participants: RR 0.90, 95% CI 0.43 to 1.90; I² = 97%; very low certainty evidence) had uncertain effects on hospitalisation for heart failure, as treatment estimates were consistent with either benefit or harm. Treatment with beta-blockers may decrease hospitalisation for heart failure (3 studies, 2287 participants: RR 0.67, 95% CI 0.43 to 1.05; I² = 87%; low certainty evidence). Aldosterone antagonists may increase the risk of hyperkalaemia compared to placebo or no treatment (3 studies, 826 participants: RR 2.91, 95% CI 2.03 to 4.17; I² = 0%; low certainty evidence). Renin inhibitors had uncertain risks of hyperkalaemia (2 studies, 142 participants: RR 0.86, 95% CI 0.49 to 1.49; I² = 0%; very low certainty). We were unable to estimate whether treatment with sinus node inhibitors affects the risk of hyperkalaemia, as there were few studies and meta-analysis was not possible. Hyperkalaemia was not reported for the CKD subgroup in studies investigating other therapies. The effects of ACEi or ARB, or aldosterone antagonists on worsening heart failure or kidney function, hypotension, or quality of life were uncertain due to sparse data or were not reported. Effects of anti-arrhythmic agents, digoxin, phosphodiesterase inhibitors, renin inhibitors, sinus node inhibitors, vasodilators, and vasopressin receptor antagonists were very uncertain due to the paucity of studies.

AUTHORS' CONCLUSIONS

The effects of pharmacological interventions for heart failure in people with CKD are uncertain and there is insufficient evidence to inform clinical practice. Study data for treatment outcomes in patients with heart failure and CKD are sparse despite the potential impact of kidney impairment on the benefits and harms of treatment. Future research aimed at analysing existing data in general population HF studies to explore the effect in subgroups of patients with CKD, considering stage of disease, may yield valuable insights for the management of people with HF and CKD.

Update on the diagnosis and management of acute heart failure

PURPOSE OF REVIEW

To highlight the advances in the diagnosis and management of acute heart failure (AHF) from recent clinical trials and observational studies.

RECENT FINDINGS

We highlight date from recent studies examining the use of novel biomarkers (micro RNAs, osteopontin, insulin-like growth-factor binding protein-7) for the diagnosis of AHF. In addition, we summarize the evidence for novel pharmacological therapies including: serelaxin, ularitide, clevidipine, urocortins, BMS-986231, TRB027, vericiguat, omecamtiv, and torsemide. Finally, we explore the evidence behind the use of novel management algorithms.

SUMMARY

Despite many advances in understanding the pathophysiology of AHF, there is currently insufficient evidence to suggest changes to standards of care.

Vascular effects of serelaxin in patients with stable coronary artery disease: a randomized placebo-controlled trial

AIMS

The effects of serelaxin, a recombinant form of human relaxin-2 peptide, on vascular function in the coronary microvascular and systemic macrovascular circulation remain largely unknown. This mechanistic, clinical study assessed the effects of serelaxin on myocardial perfusion, aortic stiffness, and safety in patients with stable coronary artery disease (CAD).

METHODS AND RESULTS

In this multicentre, double-blind, parallel-group, placebo-controlled study, 58 patients were randomized 1:1 to 48 h intravenous infusion of serelaxin (30 µg/kg/day) or matching placebo. The primary endpoints were change from baseline to 47 h post-initiation of the infusion in global myocardial perfusion reserve (MPR) assessed using adenosine stress perfusion cardiac magnetic resonance imaging, and applanation tonometry-derived augmentation index (AIx). Secondary endpoints were: change from baseline in AIx and pulse wave velocity, assessed at 47 h, Day 30, and Day 180; aortic distensibility at 47 h; pharmacokinetics and safety. Exploratory endpoints were the effect on cardiorenal biomarkers [N-terminal pro-brain natriuretic peptide (NT-proBNP), high-sensitivity troponin T (hsTnT), endothelin-1, and cystatin C]. Of 58 patients, 51 were included in the primary analysis (serelaxin, n = 25; placebo, n = 26). After 2 and 6 h of serelaxin infusion, mean placebo-corrected blood pressure reductions of -9.6 mmHg (P = 0.01) and -13.5 mmHg (P = 0.0003) for systolic blood pressure and -5.2 mmHg (P = 0.02) and -8.4 mmHg (P = 0.001) for diastolic blood pressure occurred. There were no between-group differences from baseline to 47 h in global MPR (-0.24 vs. -0.13, P = 0.44) or AIx (3.49% vs. 0.04%, P = 0.21) with serelaxin compared with placebo. Endothelin-1 and cystatin C levels decreased from baseline in the serelaxin group, and there were no clinically relevant changes observed with serelaxin for NT-proBNP or hsTnT. Similar numbers of serious adverse events were observed in both groups (serelaxin, n = 5; placebo, n = 7) to 180-day follow-up.

CONCLUSION

In patients with stable CAD, 48 h intravenous serelaxin reduced blood pressure but did not alter myocardial perfusion.

Effects of serelaxin in patients admitted for acute heart failure: a meta-analysis

AIMS

The effectiveness and safety of 48 h intravenous 30 μg/kg/day serelaxin infusion in acute heart failure (AHF) has been studied in six randomized, controlled clinical trials.

METHODS AND RESULTS

We conducted a fixed-effect meta-analysis including all studies of intravenous serelaxin initiated within the first 16 h of admission for AHF. Endpoints considered were the primary and secondary endpoints examined in the serelaxin phase III studies. In six randomized controlled trials, 6105 total patients were randomized to receive intravenous serelaxin 30 μg/kg/day and 5254 patients to control. Worsening heart failure to day 5 occurred in 6.0% and 8.1% of patients randomized to serelaxin and control, respectively (hazard ratio 0.77, 95% confidence interval 0.67-0.89; P = 0.0002). Serelaxin had no statistically significant effect on length of stay, or cardiovascular death, or heart or renal failure rehospitalization. Serelaxin administration resulted in statistically significant improvement in markers of renal function and reductions in both N-terminal pro-B-type natriuretic peptide and troponin. No significant adverse outcomes were noted with serelaxin. Through the last follow-up, which occurred at an average of 4.5 months (1-6 months), serelaxin administration was associated with a reduction in all-cause mortality, with an estimated hazard ratio of 0.87 (95% confidence interval 0.77-0.98; P = 0.0261).

CONCLUSIONS

Administration of intravenous serelaxin to patients admitted for AHF was associated with a highly significant reduction in the risk of 5-day worsening heart failure and in changes in renal function markers, but not length of stay, or cardiovascular death, or heart or renal failure rehospitalization. Serelaxin administration was safe and associated with a significant reduction in all-cause mortality.

Relaxin reverses maladaptive remodeling of the aged heart through Wnt-signaling

Healthy aging results in cardiac structural and electrical remodeling that increases susceptibility to cardiovascular diseases. Relaxin, an insulin-like hormone, suppresses atrial fibrillation, inflammation and fibrosis in aged rats but the mechanisms-of-action are unknown. Here we show that relaxin treatment of aged rats reverses pathological electrical remodeling (increasing Nav1.5 expression and localization of Connexin43 to intercalated disks) by activating canonical Wnt signaling. In isolated adult ventricular myocytes, relaxin upregulated Nav1.5 (EC₅₀ = 1.3 nM) by a mechanism inhibited by the addition of Dickkopf-1. Furthermore, relaxin increased the levels of connexin43, Wnt1, and cytosolic and nuclear β-catenin. Treatment with Wnt1 or CHIR-99021 (a GSK3β inhibitor) mimicked the relaxin effects. In isolated fibroblasts, relaxin blocked TGFβ-induced collagen elevation in a Wnt dependent manner. These findings demonstrate a close interplay between relaxin and Wnt-signaling resulting in myocardial remodeling and reveals a fundamental mechanism of great therapeutic potential.

Effects of Serelaxin in Patients with Acute Heart Failure

BACKGROUND

Serelaxin is a recombinant form of human relaxin-2, a vasodilator hormone that contributes to cardiovascular and renal adaptations during pregnancy. Previous studies have suggested that treatment with serelaxin may result in relief of symptoms and in better outcomes in patients with acute heart failure.

METHODS

In this multicenter, double-blind, placebo-controlled, event-driven trial, we enrolled patients who were hospitalized for acute heart failure and had dyspnea, vascular congestion on chest radiography, increased plasma concentrations of natriuretic peptides, mild-to-moderate renal insufficiency, and a systolic blood pressure of at least 125 mm Hg, and we randomly assigned them within 16 hours after presentation to receive either a 48-hour intravenous infusion of serelaxin (30 μg per kilogram of body weight per day) or placebo, in addition to standard care. The two primary end points were death from cardiovascular causes at 180 days and worsening heart failure at 5 days.

RESULTS

A total of 6545 patients were included in the intention-to-treat analysis. At day 180, death from cardiovascular causes had occurred in 285 of the 3274 patients (8.7%) in the serelaxin group and in 290 of the 3271 patients (8.9%) in the placebo group (hazard ratio, 0.98; 95% confidence interval [CI], 0.83 to 1.15; P = 0.77). At day 5, worsening heart failure had occurred in 227 patients (6.9%) in the serelaxin group and in 252 (7.7%) in the placebo group (hazard ratio, 0.89; 95% CI, 0.75 to 1.07; P = 0.19). There were no significant differences between the groups in the incidence of death from any cause at 180 days, the incidence of death from cardiovascular causes or rehospitalization for heart failure or renal failure at 180 days, or the length of the index hospital stay. The incidence of adverse events was similar in the two groups.

CONCLUSIONS

In this trial involving patients who were hospitalized for acute heart failure, an infusion of serelaxin did not result in a lower incidence of death from cardiovascular causes at 180 days or worsening heart failure at 5 days than placebo. (Funded by Novartis Pharma; RELAX-AHF-2 ClinicalTrials.gov number, NCT01870778.).

Therapeutic Advances in the Management of Acute Decompensated Heart Failure

BACKGROUND

Acute decompensated heart failure (ADHF) is the most common presenting phenotype of acute heart failure (AHF). The main goal of this article was to review the contemporary management strategies in these patients and to describe how future clinical trials may address unmet clinical needs.

AREAS OF UNCERTAINTY

The current pathophysiologic understanding of AHF is incomplete. The guideline recommendations for the management of ADHF are based only on algorithms provided by expert consensus guided by blood pressure and/or clinical signs of congestion or hypoperfusion. The lack of adequately conducted trials to address the unmet need for evidence therapy in AHF has not yet been surpassed, and at this time, there is no evidence-based strategy for targeted decongestive therapy to improve outcomes. The precise time point for initiation of guideline-directed medical therapies (GDMTs), as respect to moment of decompensation, is also unknown.

DATA SOURCES

The available data informing current management of patients with ADHF are based on randomized controlled trials, observational studies, and administrative databases.

THERAPEUTIC ADVANCES

A major step-forward in the management of ADHF patients is recognizing congestion, either clinical or hemodynamic, as a major trigger for heart failure (HF) hospitalization and most important target for therapy. However, a strategy based exclusively on congestion is not sufficient, and at present, comprehensive assessment during hospitalization of cardiac and noncardiovascular substrate with identification of potential therapeutic targets represents "the corner-stone" of ADHF management. In the last years, substantial data have emerged to support the continuation of GDMTs during hospitalization for HF decompensation. Recently, several clinical trials raised hypothesis of "moving to the left" concept that argues for very early implementation of GDMTs as potential strategy to improve outcomes.

CONCLUSIONS

The management of ADHF is still based on expert consensus documents. Further research is required to identify novel therapeutic targets, to establish the precise time point to initiate GDMTs, and to identify patients at risk of recurrent hospitalization.

The time-to-treatment concept in acute heart failure: Lessons and implications from REALITY-AHF

Acute heart failure (AHF) is a clinical syndrome with devastating prognosis. Despite considerable improvements in the treatment of chronic heart failure, most trials of new drugs for AHF, such as vasodilators, inotropes, and diuretics, have failed to show a prognostic benefit. Therefore, pharmacological treatment of AHF has changed very little, and loop diuretics have remained a cornerstone drug for decades. One of the emerging factors possibly playing an important role in AHF management is the time course of treatment. Several recent retrospective studies have highlighted the importance of early treatment in AHF; however, at the time, support from a prospective study with an adequate number of enrolled patients was lacking. The Registry Focused on Very Early Presentation and Treatment in Emergency Department of Acute Heart Failure (REALITY-AHF) was the first prospective study to specifically focus on the time course of treatment in the very acute phase and its prognostic implication in patients with AHF. Data from the REALITY-AHF revealed that early treatment with intravenous furosemide is significantly associated with lower in-hospital mortality. Although pathophysiological background of this association remains to be investigated, the time course of treatment may be a critical component of AHF treatment, and it will be important to take this factor into account in future clinical studies on AHF.

Relaxin-2 for heart failure with preserved ejection fraction (HFpEF): Rationale for future clinical trials

Heart Failure with preserved Ejection Fraction (HFpEF), a distinct sub-entity of chronic heart failure characterized by generalized inflammatory non-compliance of the cardio-vascular system, is associated with high mortality and still an unmet medical need. Many novel and promising therapeutic approaches have failed in large studies. This review focuses on basic research, pre-clinical and clinical findings that may account for the potential benefit of relaxin-2 in HFpEF. The peptide combines short-term hemodynamic advantages, such as moderate blood pressure decline and functional endothelin-1 antagonism, with a wealth of protective effects harboring long-term benefits, such as anti-inflammatory, anti-fibrotic, and anti-oxidative actions. These pleiotropic effects are exerted through a complex and intricate signaling cascade involving the relaxin-family peptide receptor-1, the glucocorticoid receptor, the nitric oxide system, and a cell type-dependent variety of down-stream mediators.

Cardioprotective actions of relaxin

Relaxin is a hormone of pregnancy first discovered for its ability to induce ligament relaxation in nonpregnant guinea pig and is important for softening of the birth canal during parturition, decidualization, implantation, nipple development and increased maternal renal perfusion, glomerular filtration, and cardiac output. Subsequently, relaxin has been shown to exert multiple beneficial cardiovascular effects during pathological events such as hypertension, atrial fibrillation, heart failure and myocardial infarction, including suppression of arrhythmia and inflammation, and reversal of fibrosis. Despite extensive studies, the mechanisms underlying relaxin's effects are not well understood. Relaxin signals primarily through its G protein coupled receptor, the relaxin family peptide receptor-1, to activate multiple signaling pathways and this review summarizes our understanding of these pathways as they relate to the cardioprotective actions of relaxin, focusing on relaxin's anti-fibrotic, anti-arrhythmic and anti-inflammatory properties. Further, this review includes a brief overview of relaxin in clinical trials for heart failure and progress in the development of relaxin mimetics.

Recent developments in relaxin mimetics as therapeutics for cardiovascular diseases

Cardiovascular disease is the most common cause of mortality worldwide, accounting for almost 50% of all deaths globally. Vascular endothelial dysfunction and fibrosis are critical in the pathophysiology of cardiovascular disease. Relaxin, an insulin-like peptide, is known to have beneficial actions in the cardiovascular system through its vasoprotective and anti-fibrotic effects. However, relaxin has several limitations of peptide-based drugs such as poor oral bioavailability, laborious, and expensive to synthesize. This review will focus on recent developments in relaxin mimetics, their pharmacology, associated signalling mechanisms, and their therapeutic potential for the management and treatment of cardiovascular disease.

Update on the management of acute heart failure

PURPOSE OF REVIEW

We provide a concise review of recent studies focusing on the management of patients with acute heart failure (AHF).

RECENT FINDINGS

In well designed randomized trials, no mortality benefit has been observed with the use of diuretics, ultrafiltration, inotropes and vasodilators in AHF. Recent trials examining the role of novel inotropes and vasodilators as well as the role of mineralocorticoid receptor antagonists in the AHF population, is reviewed.

SUMMARY

The focus of therapy in AHF should be directed towards symptom management. No mortality benefit has been observed despite good quality studies.