Hemodynamic, Echocardiographic, and Neurohormonal Effects of Istaroxime, a Novel Intravenous Inotropic and Lusitropic Agent

Safety and efficacy of up to 60 h of iv istaroxime in pre-cardiogenic shock patients: Design of the SEISMiC trial

AIMS

Cardiogenic shock (CS) is linked to high morbidity and mortality rates, posing a challenge for clinicians. Interventions to improve tissue perfusion and blood pressure are crucial to prevent further deterioration. Unfortunately, current inotropes, which act through adrenergic receptor stimulation, are associated with malignant arrhythmias and poorer outcomes. Due to its unique mechanism of action, istaroxime should improve haemodynamics without adrenergic overactivation. The SEISMiC study is designed to examine the safety and efficacy (haemodynamic effect) of istaroxime administrated in pre-CS patients.

METHODS AND RESULTS

The SEISMiC study is a multinational, multicentre, randomized, double-blind, placebo-controlled safety and efficacy study with two parts (A and B). The study enrols patients hospitalized for decompensated heart failure (pre-CS, not related to myocardial ischaemia) with persistent hypotension [systolic blood pressure (SBP) 70-100 mmHg for at least 2 h] and clinically confirmed congestion, NT-proBNP ≥1400 pg/mL, and LVEF≤40%. Subjects must not have taken intravenous (iv) vasopressors, inotropes or digoxin in the past 6 h. Eligible patients are randomized to receive IV infusion of istaroxime (different doses and regimens in Parts A and B) or placebo for up to 60 h. Central haemodynamics, ECG Holter monitoring, cardiac ultrasound and biomarkers are recorded at predefined time points during the trial. The study's primary efficacy endpoint is the SBP area under the curve from baseline curve from baseline to 6 and 24 h in the combined SEISMiC Parts A and B population. Key secondary efficacy endpoints include haemodynamic, laboratory and clinical measures in SEISMiC B alone in the combined SEISMiC A and B studies.

CONCLUSIONS

The study results will contribute to our understanding of the role of istaroxime in pre-CS patients and potentially provide insight into the drug's haemodynamic effects and safety in this population.

Medical therapy of cardiogenic shock: Contemporary use of inotropes and vasopressors

Cardiogenic shock is a primary cardiac disorder that results in both clinical and biochemical evidence of tissue hypoperfusion and can lead to multi-organ failure and death depending on its severity. Inadequate cardiac contractility or cardiac power secondary to acute myocardial infarction remains the most frequent cause of cardiogenic shock, although its contribution has declined over the past two decades, compared with other causes. Despite some advances in cardiogenic shock management, this clinical syndrome is still burdened by an extremely high mortality. Its management is based on immediate stabilization of haemodynamic parameters so that further treatment, including mechanical circulatory support and transfer to specialized tertiary care centres, can be accomplished. With these aims, medical therapy, consisting mainly of inotropic drugs and vasopressors, still has a major role. The purpose of this article is to review current evidence on the use of these medications in patients with cardiogenic shock and discuss specific clinical settings with indications to their use.

Selective SERCA2a activator as a candidate for chronic heart failure therapy

BACKGROUND

The sarcoplasmic reticulum (SR) Ca2+ ATPase (SERCA2a) depression substantially contributes to diastolic dysfunction in heart failure (HF), suggesting that SERCA2a stimulation may be a mechanism-based HF therapy. Istaroxime is a drug endowed with both a SERCA2a stimulatory activity and a Na+/K+ pump inhibitory activity for acute HF treatment. Its main metabolite PST3093 shows a more favorable therapeutic profile as compared to the parent drug, but it is still unsuitable for chronic usage. Novel PST3093 derivatives have been recently developed for oral (chronic) HF treatment; compound 8 was selected among them and here characterized.

METHODS

Effects of compound 8 were evaluated in a context of SERCA2a depression, by using streptozotocin-treated rats, a well-known model of diastolic dysfunction. The impact of SERCA2a stimulation by compound 8 was assessed at the cellular level ad in vivo, following i.v. infusion (acute effects) or oral administration (chronic effects).

RESULTS

As expected from SERCA2a stimulation, compound 8 induced SR Ca2+ compartmentalization in STZ myocytes. In-vivo echocardiographic analysis during i.v. infusion and after repeated oral administration of compound 8, detected a significant improvement of diastolic function. Moreover, compound 8 did not affect electrical activity of healthy guinea-pig myocytes, in line with the absence of off-target effects. Finally, compound 8 was well tolerated in mice with no evidence of acute toxicity.

CONCLUSIONS

The pharmacological evaluation of compound 8 indicates that it may be a safe and selective drug for a mechanism-based treatment of chronic HF by restoring SERCA2a activity.

Istaroxime for Patients with Acute Heart Failure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Istaroxime, an intravenous inotropic agent with a dual mechanism-increasing both cardiomyocyte contractility and relaxation-is a novel treatment for acute heart failure (AHF), the leading cause of morbidity and mortality in heart failure. We conducted a systematic review and meta-analysis that synthesized randomized controlled trials (RCTs), which were retrieved by systematically searching PubMed, Web of Science, SCOPUS, and Cochrane until 24 April 2023. We used a fixed-effect or random-effect model-according to heterogeneity-to pool dichotomous data using the risk ratio (RR) and continuous data using the mean difference (MD), with a 95% confidence interval (CI). We included three RCTs with a total of 300 patients. Istaroxime was significantly associated with an increased left ventricular ejection fraction (mL) (MD: 1.06, 95% CI: 0.29, 1.82; p = 0.007), stroke volume index (MD: 3.04, 95% CI: 2.41, 3.67; p = 0.00001), and cardiac index (L/min/m2) (MD: 0.18, 95% CI: 0.11, 025; p = 0.00001). Also, istaroxime was significantly associated with a decreased E/A ratio (MD: -0.39, 95% CI: -0.58, -0.19; p = 0.0001) and pulmonary artery systolic pressure (mmHg) (MD: 2.30, 95% CI: 3.20, 1.40; p = 0.00001). Istaroxime was significantly associated with increased systolic blood pressure (mmHg) (MD: 5.32, 95% CI: 2.28, 8.37; p = 0.0006) and decreased heart rate (bpm) (MD: -3.05, 95% CI: -5.27, -0.82; p = 0.007). Since istaroxime improved hemodynamic and echocardiographic parameters, it constitutes a promising strategy for AHF management. However, the current literature is limited to a small number of RCTs, warranting further large-scale phase III trials before clinical endorsement.

Istaroxime: A Novel Therapeutic Agent for Acute Heart Failure

Acute decompensated heart failure (ADHF) is a multifactorial process that is associated with high morbidity and mortality. Treatment with inotropes can rapidly improve hemodynamic status; however, their use has been associated with increased mortality and incidence of arrhythmias. Istaroxime is a first-in-class intravenous agent currently undergoing clinical trials for acute heart failure. It has the unique mechanism of action of both Na+/K+ ATPase inhibition and sarcoplasmic/endoplasmic reticulum Ca2+ ATPase 2a stimulation. Notably, its action on sarcoplasmic/endoplasmic reticulum Ca2+ ATPase 2a improves calcium handling, which is known to be abnormal in heart failure. Clinical trials have shown that istaroxime has beneficial hemodynamic effects; in particular, its ability to increase systolic blood pressure without causing significant increases in heart rate or clinically significant arrhythmias differentiates it from inotropes currently utilized for ADHF treatment, such as milrinone. While initial studies are encouraging, additional trials are needed to assess outcomes and to compare their performance to standard inotropes in patients hospitalized with ADHF. This article will review the relevant preclinical and clinical trials for istaroxime, as well as the relevant pharmacology.

Safety and Efficacy of Istaroxime 1.0 and 1.5 µg/kg/min for Patients With Pre-Cardiogenic Shock

INTRODUCTION

Istaroxime was shown, in a small study, to increase systolic blood pressure (SBP) in patients with pre-cardiogenic shock (CS) due to acute heart failure (AHF).

OBJECTIVES

In the current analysis, we describe the effects of 2 doses of istaroxime 1.0 (Ista-1) and 1.5 µg/kg/min (Ista-1.5).

METHODS

The target dose of istaroxime, administered in a double-blind, placebo-controlled fashion, was 1.5 µg/kg/min in the first cohort (n = 24), and it was reduced to 1.0 µg/kg/min in subsequent patients (n = 36).

RESULTS

Ista-1 was associated with numerically larger effects on SBP area under the curve, with a 93.6% relative increase from baseline during the first 6 hours with Ista-1 vs 39.5% for Ista-1.5, and with a 49.4% and 24.3% relative increase, respectively, at 24 hours. Compared to placebo, Ista-1.5 had more worsening HF events until day 5 and fewer days alive out of hospital (DAOH) through day 30. Ista-1 had no worsening HF events, and DAOH to day 30 were significantly increased. Effects on echocardiographic measures were similar, although decreases in left ventricular end systolic and diastolic volumes were numerically larger in the Ista-1 group. Ista-1, but not Ista-1.5, showed numerically smaller creatinine increases and larger decreases in natriuretic peptides as compared to placebo. There were 5 serious adverse events in Ista-1.5 (4 of which were cardiac) but only 1 in Ista-1.

CONCLUSIONS

In patients with pre-CS due to AHF, istaroxime 1.0 µg/kg/min induced beneficial effects on SBP and DAOH. Clinical benefits appear to be reached at dosages less than 1.5 ug/kg/min.

The current and future status of inotropes in heart failure management

INTRODUCTION

Heart failure (HF) is a complex syndrome with a wide range of presentations and acuity, ranging from outpatient care to inpatient management due to acute decompensated HF, cardiogenic shock or advanced HF. Frequently, the etiology of a patient's decompensation is diminished cardiac output and peripheral hypoperfusion. Consequently, there is a need for use of inotropes, agents that increase cardiac contractility, optimize hemodynamics and ensure adequate perfusion.

AREAS COVERED

Inotropes are divided into 3 major classes: beta agonists, phosphodiesterase III inhibitors and calcium sensitizers. Additionally, as data from prospective studies accumulates, novel agents are emerging, including omecamtiv mecarbil and istaroxime. The aim of this review is to summarize current data on the optimal use of inotropes and to provide an expert opinion regarding their current and future use in the management of HF.

EXPERT OPINION

The use of inotropes has long been linked to worsening mortality, tachyarrhythmias, increased myocardial oxygen consumption and ischemia. Therefore, individualized and evidence-based treatment plans for patients who require inotropic support are necessary. Also, better quality data on the use of existing inotropes is imperative, while the development of newer and safer agents will lead to more effective management of patients with HF in the future.

Safety and Efficacy of Istaroxime in Patients With Acute Heart Failure: A Meta-Analysis of Randomized Controlled Trials

The aim of this study was to assess the efficacy and safety of istaroxime in patients with heart failure. Following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines, a search was conducted on the EMBASE and Medline databases to identify articles related to the safety and efficacy of istaroxime in patients with heart failure. The search covered the period from inception to May 31st, 2023, without any restrictions on the year of publication. The search strategy utilized relevant terms such as "istaroxime," "heart failure", "efficacy," and other related terms, along with their corresponding Medical Subject Headings (MeSH) terms. The outcomes assessed in this meta-analysis included the change in left ventricular ejection fraction (LVEF), E to A ratio (a marker of left ventricle function), cardiac index in L/min/m2, systolic blood pressure (SBP) in mmHg, left ventricular end-systolic volume (LVESV) in ml, and left ventricular end-diastolic volume (LVDSV) in ml. For safety analysis, gastrointestinal events and cardiovascular events were assessed. A total of three randomized controlled trials (RCTs) were included in this meta-analysis encompassing 211 patients with heart failure. Pooled analysis showed that istaroxime was effective in increasing LVEF (MD: 1.26, 95% CI: 0.91 to 1.62, p-value: 0.001), reducing E to A ratio (MD: -0.39, 95% CI: -0.60 to -0.19, p-value: 0.001), increasing cardiac index (MD: 0.22, 95% CI: 0.18 to 0.25, p-value: 0.001), reducing LVESV (MD: -11.84, 95% CI: -13.91 to -9.78, p-value: 0.001), reducing LVEDV (MD: -12.25, 95% CI: -14.63 to -9.87, p-value: 0.001) and increasing SBP (MD: 8.41, 95% CI: 5.23 to 11.60, p-value: 0.001) compared to the placebo group. However, risk of gastrointestinal events was significantly higher in patients receiving istaroxime compared to the placebo group (RR: 2.64, 95% CI: 1.53 to 4.57, p-value: 0.0005). These findings support the enhancement of heart function with istaroxime administration, aligning with previous clinical and experimental evidence.

SERCA2a Agonist Effects on Cardiac Performance During Exercise in Heart Failure With Preserved Ejection Fraction

BACKGROUND

Impaired ventricular relaxation influences left ventricular pressures during exercise in heart failure with preserved ejection fraction (HFpEF). Sarco/endoplasmic reticulum calcium-adenosine triphosphatase (SERCA2a) facilitates myocardial relaxation by increasing calcium reuptake and is impaired in HFpEF.

OBJECTIVES

This study sought to investigate the effects of istaroxime, a SERCA2 agonist, on lusitropic and hemodynamic function during exercise in patients with HFpEF and control subjects.

METHODS

Eleven control subjects (7 male, 4 female) and 15 patients with HFpEF (8 male, 7 female) performed upright cycle exercise with right-sided heart catheterization. Participants received istaroxime (0.5 mg/kg/min) or saline placebo (single-blind, crossover design). Cardiac output, pulmonary capillary wedge pressure (PCWP), and diastolic function were measured at rest and during submaximal exercise. In an exploratory analysis (Hedges' g), 7 patients with HFpEF received higher-dose istaroxime (1.0 mg/kg/min). End-systolic elastance (Ees) was calculated by dividing systolic blood pressure (SBP) × 0.9 by end-systolic volume (ESV; on 3-dimensional echocardiography).

RESULTS

Patients with HFpEF had higher PCWP (25 ± 10 mm Hg vs 12 ± 5 mm Hg; P < 0.001) and lower tissue Doppler velocities during exercise. Istaroxime (0.5 mg/kg/min) had no effect on resting or exercise measures in patients with HFpEF or control subjects. Control subjects had a larger increase in Ees (Δ 1.55 ± 0.99 mm Hg/mL vs D 0.86 ± 1.31 mm Hg/mL; P = 0.03), driven by lower ESV. Comparing placebo and istaroxime 1.0 mg /kg/min during exercise, PCWP during the 1.0 mg /kg/min istaroxime dose was slightly lower (Δ 2.2 mm Hg; Hedges' g = 0.30). There were no effects on diastolic function, but there were increases in SBP and s', suggesting a mild inotropic effect.

CONCLUSIONS

Low-dose istaroxime had no effect on cardiac filling pressure or parameters of relaxation in patients with HFpEF during exercise. Higher doses of istaroxime may have been more effective in reducing exercise PCWP in patients with HFpEF. (Hemodynamic Response to Exercise in HFpEF Patients After Upregulation of SERCA2a; NCT02772068).

Istaroxime Metabolite PST3093 Selectively Stimulates SERCA2a and Reverses Disease-Induced Changes in Cardiac Function

Heart failure (HF) therapeutic toolkit would strongly benefit from the availability of ino-lusitropic agents with a favorable pharmacodynamics and safety profile. Istaroxime is a promising agent, which combines Na+/K+ pump inhibition with sarcoplasmic reticulum Ca2+ ATPase (SERCA2a) stimulation; however, it has a very short half-life and extensive metabolism to a molecule named PST3093. The present work aims to investigate whether PST3093 still retains the pharmacodynamic and pharmacokinetic properties of its parent compound. We studied PST3093 for its effects on SERCA2a and Na+/K+ ATPase activities, Ca2+ dynamics in isolated myocytes, and hemodynamic effects in an in vivo rat model of diabetic [streptozotocin (STZ)-induced] cardiomyopathy. Istaroxime infusion in HF patients led to accumulation of PST3093 in the plasma; clearance was substantially slower for PST3093 than for istaroxime. In cardiac rat preparations, PST3093 did not inhibit the Na+/K+ ATPase activity but retained SERCA2a stimulatory activity. In in vivo echocardiographic assessment, PST3093 improved overall cardiac performance and reversed most STZ-induced abnormalities. PST3093 intravenous toxicity was considerably lower than that of istaroxime, and it failed to significantly interact with 50 off-targets. Overall, PST3093 is a "selective" SERCA2a activator, the prototype of a novel pharmacodynamic category with a potential in the ino-lusitropic approach to HF with prevailing diastolic dysfunction. Its pharmacodynamics are peculiar, and its pharmacokinetics are suitable to prolong the cardiac beneficial effect of istaroxime infusion. SIGNIFICANCE STATEMENT: Heart failure (HF) treatment would benefit from the availability of ino-lusitropic agents with favourable profiles. PST3093 is the main metabolite of istaroxime, a promising agent combining Na+/K+ pump inhibition and sarcoplasmic reticulum Ca2+ ATPase2a (SERCA2a) stimulation. PST3093 shows a longer half-life in human circulation compared to istaroxime, selectively activates SERCA2a, and improves cardiac performance in a model of diabetic cardiomyopathy. Overall, PST3093 as a selective SERCA2a activator can be considered the prototype of a novel pharmacodynamic category for HF treatment.

Efficacy of the New Inotropic Agent Istaroxime in Acute Heart Failure

Current therapeutic strategies for acute heart failure (AHF) are based on traditional inotropic agents that are often associated with untoward effects; therefore, finding new effective approaches with a safer profile is dramatically needed. Istaroxime is a novel compound, chemically unrelated to cardiac glycosides, that is currently being studied for the treatment of AHF. Its effects are essentially related to its inotropic and lusitropic positive properties exerted through a dual mechanism of action: activation of the sarcoplasmic reticulum Ca2+ ATPase isoform 2a (SERCA2a) and inhibition of the Na+/K+-ATPase (NKA) activity. The advantages of istaroxime over the available inotropic agents include its lower arrhythmogenic action combined with its capability of increasing systolic blood pressure without augmenting heart rate. However, it has a limited half-life (1 hour) and is associated with adverse effects including pain at the injection site and gastrointestinal issues. Herein, we describe the main mechanism of action of istaroxime and we present a systematic overview of both clinical and preclinical trials testing this drug, underlining the latest insights regarding its adoption in clinical practice for AHF.

Safety and efficacy of istaroxime in patients with acute heart failure-related pre-cardiogenic shock - a multicentre, randomized, double-blind, placebo-controlled, parallel group study (SEISMiC)

AIMS

We examined the effects of istaroxime in patients hospitalized for acute heart failure (AHF) related Society for Cardiovascular Angiography and Interventions (SCAI) stage B pre-cardiogenic shock (CS).

METHODS AND RESULTS

Sixty patients with AHF without acute myocardial infarction with pre-CS, defined as systolic blood pressure (SBP) <90 mmHg without hypoperfusion, venous lactate ≥2 mmol/L and/or mechanical or inotropic support, were randomized to istaroxime 1.0-1.5 μg/kg/min or placebo for 24 h. The primary endpoint, the adjusted area under the curve (AUC) change in SBP from time of treatment to 6 h, was 53.1 (standard error [SE] 6.88) mmHg × hour versus 30.9 (SE 6.76) mmHg × hour with istaroxime versus placebo (p = 0.017). Adjusted SBP AUC at 24 h was 291.2 (SE 27.5) versus 208.7 (SE 27.0) mmHg × hour (p = 0.025). At 24 h, some echocardiographic measurements improved with istaroxime versus placebo including cardiac index (+0.21 L/min/m² ; p = 0.016), left atrial area (-1.8 cm² ; p = 0.008), and left ventricular end-systolic volume (-12.0 ml; p = 0.034). There were no significant differences in pulse pressure, laboratory measurements, serious adverse events or adverse events between the treatment groups except for more nausea, vomiting and infusion site pain in the istaroxime-treated patients. In a post-hoc analysis, patients receiving ≤1.0 μg/kg/min versus 1.5 μg/kg/min had similar increase in blood pressure, but a trend towards less adverse events.

CONCLUSION

In a phase 2a study of patients with AHF related pre-CS, istaroxime improved blood pressure and some echocardiography measures related to heart failure and was well tolerated.

Highly Selective SERCA2a Activators: Preclinical Development of a Congeneric Group of First-in-Class Drug Leads against Heart Failure

The stimulation of sarcoplasmic reticulum calcium ATPase SERCA2a emerged as a novel therapeutic strategy to efficiently improve overall cardiac function in heart failure (HF) with reduced arrhythmogenic risk. Istaroxime is a clinical-phase IIb compound with a double mechanism of action, Na+/K+ ATPase inhibition and SERCA2a stimulation. Starting from the observation that istaroxime metabolite PST3093 does not inhibit Na+/K+ ATPase while stimulates SERCA2a, we synthesized a series of bioisosteric PST3093 analogues devoid of Na+/K+ ATPase inhibitory activity. Most of them retained SERCA2a stimulatory action with nanomolar potency in cardiac preparations from healthy guinea pigs and streptozotocin (STZ)-treated rats. One compound was further characterized in isolated cardiomyocytes, confirming SERCA2a stimulation and in vivo showing a safety profile and improvement of cardiac performance following acute infusion in STZ rats. We identified a new class of selective SERCA2a activators as first-in-class drug candidates for HF treatment.

Calcium dysregulation in heart diseases: Targeting calcium channels to achieve a correct calcium homeostasis

Intracellular calcium signaling is a universal language source shared by the most part of biological entities inside cells that, all together, give rise to physiological and functional anatomical units, the organ. Although preferentially recognized as signaling between cell life and death processes, in the heart it assumes additional relevance considered the importance of calcium cycling coupled to ATP consumption in excitation-contraction coupling. The concerted action of a plethora of exchangers, channels and pumps inward and outward calcium fluxes where needed, to convert energy and electric impulses in muscle contraction. All this without realizing it, thousands of times, every day. An improper function of those proteins (i.e., variation in expression, mutations onset, dysregulated channeling, differential protein-protein interactions) being part of this signaling network triggers a short circuit with severe acute and chronic pathological consequences reported as arrhythmias, cardiac remodeling, heart failure, reperfusion injury and cardiomyopathies. By acting with chemical, peptide-based and pharmacological modulators of these players, a correction of calcium homeostasis can be achieved accompanied by an amelioration of clinical symptoms. This review will focus on all those defects in calcium homeostasis which occur in the most common cardiac diseases, including myocardial infarction, arrhythmia, hypertrophy, heart failure and cardiomyopathies. This part will be introduced by the state of the art on the proteins involved in calcium homeostasis in cardiomyocytes and followed by the therapeutic treatments that to date, are able to target them and to revert the pathological phenotype.

Istaroxime treatment ameliorates calcium dysregulation in a zebrafish model of phospholamban R14del cardiomyopathy

The heterozygous Phospholamban p.Arg14del mutation is found in patients with dilated or arrhythmogenic cardiomyopathy. This mutation triggers cardiac contractile dysfunction and arrhythmogenesis by affecting intracellular Ca2+ dynamics. Little is known about the physiological processes preceding induced cardiomyopathy, which is characterized by sub-epicardial accumulation of fibrofatty tissue, and a specific drug treatment is currently lacking. Here, we address these issues using a knock-in Phospholamban p.Arg14del zebrafish model. Hearts from adult zebrafish with this mutation display age-related remodeling with sub-epicardial inflammation and fibrosis. Echocardiography reveals contractile variations before overt structural changes occur, which correlates at the cellular level with action potential duration alternans. These functional alterations are preceded by diminished Ca2+ transient amplitudes in embryonic hearts as well as an increase in diastolic Ca2+ level, slower Ca2+ transient decay and longer Ca2+ transients in cells of adult hearts. We find that istaroxime treatment ameliorates the in vivo Ca2+ dysregulation, rescues the cellular action potential duration alternans, while it improves cardiac relaxation. Thus, we present insight into the pathophysiology of Phospholamban p.Arg14del cardiomyopathy.

Comparing the reporting and conduct quality of exercise and pharmacological randomised controlled trials: a systematic review

OBJECTIVE

Evaluate the quality of exercise randomised controlled trial (RCT) reporting and conduct in clinical populations (ie, adults with or at risk of chronic conditions) and compare with matched pharmacological RCTs.

DESIGN

Systematic review.

DATA SOURCES

Embase (Elsevier), PubMed (NLM) and CINAHL (EBSCO).

STUDY SELECTION

RCTs of exercise in clinical populations with matching pharmacological RCTs published in leading clinical, medical and specialist journals with impact factors ≥15.

REVIEW METHODS

Overall RCT quality was evaluated by two independent reviewers using three research reporting guidelines (ie, Consolidated Standards of Reporting Trials (CONSORT; pharmacological RCTs)/CONSORT for non-pharmacological treatments; exercise RCTs), CONSORT-Harms, Template for Intervention Description and Replication) and two risk of bias assessment (research conduct) tools (ie, Cochrane Risk of Bias, Jadad Scale). We compared research reporting and conduct quality within exercise RCTs with matched pharmacological RCTs, and examined factors associated with quality in exercise and pharmacological RCTs, separately.

FINDINGS

Forty-eight exercise RCTs (11 658 patients; median sample n=138) and 48 matched pharmacological RCTs were evaluated (18 501 patients; median sample n=160). RCTs were conducted primarily in cardiovascular medicine (43%) or oncology (31%). Overall quality score (composite of all research reporting and conduct quality scores; primary endpoint) for exercise RCTs was 58% (median score 46 of 80; IQR: 39-51) compared with 77% (53 of 68; IQR: 47-58) in the matched pharmacological RCTs (p≤0.001). Individual quality scores for trial reporting and conduct were lower in exercise RCTs compared with matched pharmacological RCTs (p≤0.03). Factors associated with higher overall quality scores for exercise RCTs were journal impact factor (≥25), sample size (≥152) and publication year (≥2013).

CONCLUSIONS AND RELEVANCE

Research reporting and conduct quality within exercise RCTs is inferior to matched pharmacological RCTs. Suboptimal RCT reporting and conduct impact the fidelity, interpretation, and reproducibility of exercise trials and, ultimately, implementation of exercise in clinical populations.

PROSPERO REGISTRATION NUMBER

CRD42018095033.

Pathophysiology and Therapeutic Approaches to Acute Decompensated Heart Failure

Acute decompensated heart failure (ADHF) is one of the leading admission diagnoses worldwide, yet it is an entity with incompletely understood pathophysiology and limited therapeutic options. Patients admitted for ADHF have high in-hospital morbidity and mortality, as well as frequent rehospitalizations and subsequent cardiovascular death. This devastating clinical course is partly due to suboptimal medical management of ADHF with persistent congestion upon hospital discharge and inadequate predischarge initiation of life-saving guideline-directed therapies. While new drugs for the treatment of chronic HF continue to be approved, there has been no new therapy approved for ADHF in decades. This review will focus on the current limited understanding of ADHF pathophysiology, possible therapeutic targets, and current limitations in expanding available therapies in light of the unmet need among these high-risk patients.

Cardiac foetal reprogramming: a tool to exploit novel treatment targets for the failing heart

As the heart matures during embryogenesis from its foetal stages, several structural and functional modifications take place to form the adult heart. This process of maturation is in large part due to an increased volume and work load of the heart to maintain proper circulation throughout the growing body. In recent years, it has been observed that these changes are reversed to some extent as a result of cardiac disease. The process by which this occurs has been characterized as cardiac foetal reprogramming and is defined as the suppression of adult and re-activation of a foetal genes profile in the diseased myocardium. The reasons as to why this process occurs in the diseased myocardium are unknown; however, it has been suggested to be an adaptive process to counteract deleterious events taking place during cardiac remodelling. Although still in its infancy, several studies have demonstrated that targeting foetal reprogramming in heart failure can lead to substantial improvement in cardiac functionality. This is highlighted by a recent study which found that by modulating the expression of 5-oxoprolinase (OPLAH, a novel cardiac foetal gene), cardiac function can be significantly improved in mice exposed to cardiac injury. Additionally, the utilization of angiotensin receptor neprilysin inhibitors (ARNI) has demonstrated clear benefits, providing important clinical proof that drugs that increase natriuretic peptide levels (part of the foetal gene programme) indeed improve heart failure outcomes. In this review, we will highlight the most important aspects of cardiac foetal reprogramming and will discuss whether this process is a cause or consequence of heart failure. Based on this, we will also explain how a deeper understanding of this process may result in the development of novel therapeutic strategies in heart failure.

Altered atrial cytosolic calcium handling contributes to the development of postoperative atrial fibrillation

Aims 

Atrial fibrillation (AF) is a commonly occurring arrhythmia after cardiac surgery (postoperative AF, poAF) and is associated with poorer outcomes. Considering that reduced atrial contractile function is a predictor of poAF and that Ca²⁺ plays an important role in both excitation–contraction coupling and atrial arrhythmogenesis, this study aims to test whether alterations of intracellular Ca²⁺ handling contribute to impaired atrial contractility and to the arrhythmogenic substrate predisposing patients to poAF.

Methods and results 

Right atrial appendages were obtained from patients in sinus rhythm undergoing open-heart surgery. Cardiomyocytes were investigated by simultaneous measurement of [Ca²⁺]_i and action potentials (APs, patch-clamp). Patients were followed-up for 6 days to identify those with and without poAF. Speckle-tracking analysis of preoperative echocardiography revealed reduced left atrial contraction strain in poAF patients. At the time of surgery, cellular Ca²⁺ transients (CaTs) and the sarcoplasmic reticulum (SR) Ca²⁺ content were smaller in the poAF group. CaT decay was slower in poAF, but the decay of caffeine-induced Ca²⁺ transients was unaltered, suggesting preserved sodium-calcium exchanger function. In agreement, western blots revealed reduced SERCA2a expression in poAF patients but unaltered phospholamban expression/phosphorylation. Computational modelling indicated that reduced SERCA activity promotes occurrence of CaT and AP alternans. Indeed, alternans of CaT and AP occurred more often and at lower stimulation frequencies in atrial myocytes from poAF patients. Resting membrane potential and AP duration were comparable between both groups at various pacing frequencies (0.25–8 Hz).

Conclusions 

Biochemical, functional, and modelling data implicate reduced SERCA-mediated Ca²⁺ reuptake into the SR as a major contributor to impaired preoperative atrial contractile function and to the pre-existing arrhythmogenic substrate in patients developing poAF.

Pathogenesis and pathophysiology of heart failure with reduced ejection fraction: translation to human studies

Heart failure represents the end result of different pathophysiologic processes, which culminate in functional impairment. Regardless of its aetiology, the presentation of heart failure usually involves symptoms of pump failure and congestion, which forms the basis for clinical diagnosis. Pathophysiologic descriptions of heart failure with reduced ejection fraction (HFrEF) are being established. Most commonly, HFrEF is centred on a reactive model where a significant initial insult leads to reduced cardiac output, further triggering a cascade of maladaptive processes. Predisposing factors include myocardial injury of any cause, chronically abnormal loading due to hypertension, valvular disease, or tachyarrhythmias. The pathophysiologic processes behind remodelling in heart failure are complex and reflect systemic neurohormonal activation, peripheral vascular effects and localised changes affecting the cardiac substrate. These abnormalities have been the subject of intense research. Much of the translational successes in HFrEF have come from targeting neurohormonal responses to reduced cardiac output, with blockade of the renin-angiotensin-aldosterone system (RAAS) and beta-adrenergic blockade being particularly fruitful. However, mortality and morbidity associated with heart failure remains high. Although systemic neurohormonal blockade slows disease progression, localised ventricular remodelling still adversely affects contractile function. Novel therapy targeted at improving cardiac contractile mechanics in HFrEF hold the promise of alleviating heart failure at its source, yet so far none has found success. Nevertheless, there are increasing calls for a proximal, 'cardiocentric' approach to therapy. In this review, we examine HFrEF therapy aimed at improving cardiac function with a focus on recent trials and emerging targets.

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.

Treatment with 24 hour istaroxime infusion in patients hospitalised for acute heart failure: a randomised, placebo-controlled trial

AIM

Istaroxime is a first-in-class agent which acts through inhibition of the sarcolemmal Na⁺ /K⁺ pump and activation of the SERCA2a pump. This study assessed the effects of a 24 h infusion of istaroxime in patients hospitalised for acute heart failure (AHF).

METHODS AND RESULTS

We included patients hospitalised for AHF with left ventricular ejection fraction ≤40% and E/e' > 10. Patients were randomised to a 24 h intravenous infusion of placebo or istaroxime at doses of 0.5 μg/kg/min (cohort 1: placebo n = 19; istaroxime n = 41) or 1.0 μg/kg/min (cohort 2: placebo n = 20, istaroxime n = 40). The primary endpoint of change in E/e' ratio from baseline to 24 h decreased with istaroxime vs. placebo (cohort 1: -4.55 ± 4.75 istaroxime 0.5 μg/kg/min vs. -1.55 ± 4.11 placebo, P = 0.029; cohort 2: -3.16 ± 2.59 istaroxime 1.0 μg/kg/min vs. -1.08 ± 2.72 placebo, P = 0.009). Both istaroxime doses significantly increased stroke volume index and decreased heart rate. Systolic blood pressure increased with istaroxime, achieving significance with the high dose. Self-reported dyspnoea and N-terminal pro-brain natriuretic peptide improved in all groups without significant differences between istaroxime and placebo. No significant differences in cardiac troponin absolute values or clinically relevant arrhythmias were observed during or after istaroxime infusion. Serious cardiac adverse events (including arrhythmias and hypotension) did not differ between placebo and istaroxime groups. The most common adverse events were injection site reactions and gastrointestinal events, the latter primarily with istaroxime 1.0 μg/kg/min.

CONCLUSIONS

In patients hospitalised for AHF with reduced ejection fraction, a 24 h infusion of istaroxime improved parameters of diastolic and systolic cardiac function without major cardiac adverse effects.

Old and New Drugs for Treatment of Advanced Heart Failure

BACKGROUND

Advanced heart failure (HF) is a progressive disease with high mortality and limited medical therapeutic options. Long-term mechanical circulatory support and heart transplantation remain goldstandard treatments for these patients; however, access to these therapies is limited by the advanced age and multiple comorbidities of affected patients, as well as by the limited number of organs available.

METHODS

Traditional and new drugs available for the treatment of advanced HF have been researched.

RESULTS

To date, the cornerstone for the treatment of patients with advanced HF remains water restriction, intravenous loop diuretic therapy and inotropic support. However, many patients with advanced HF experience loop diuretics resistance and alternative therapeutic strategies to overcome this problem have been developed, including sequential nephron blockade or use of the hypertonic saline solution in combination with high-doses of furosemide. As classic inotropes augment myocardial oxygen consumption, new promising drugs have been introduced, including levosimendan, istaroxime and omecamtiv mecarbil. However, pharmacological agents still remain mainly short-term or palliative options in patients with acute decompensation or excluded from mechanical therapy.

CONCLUSION

Traditional drugs, especially when administered in combination, and new medicaments represent important therapeutic options in advanced HF. However, their impact on prognosis remains unclear. Large trials are necessary to clarify their therapeutic potential and prognostic role in these fragile patients.

Factors Affecting Cardiovascular Physiology in Cardiothoracic Surgery: Implications for Lumped-Parameter Modeling

Cardiothoracic surgeries are complex procedures during which the patient cardiovascular physiology is constantly changing due to various factors. Physiological changes begin with the induction of anesthesia, whose effects remain active into the postoperative period. Depending on the surgery, patients may require the use of cardiopulmonary bypass and cardioplegia, both of which affect postoperative physiology such as cardiac index and vascular resistance. Complications may arise due to adverse reactions to the surgery, causing hemodynamic instability. In response, fluid resuscitation and/or vasoactive agents with varying effects may be used in the intraoperative or postoperative periods to improve patient hemodynamics. These factors have important implications for lumped-parameter computational models which aim to assist surgical planning and medical device evaluation. Patient-specific models are typically tuned based on patient clinical data which may be asynchronously acquired through invasive techniques such as catheterization, during which the patient may be under the effects of drugs such as anesthesia. Due to the limited clinical data available and the inability to foresee short-term physiological regulation, models often retain preoperative parameters for postoperative predictions; however, without accounting for the physiologic changes that may occur during surgical procedures, the accuracy of these predictive models remains limited. Understanding and incorporating the effects of these factors in cardiovascular models will improve the model fidelity and predictive capabilities.

Short-Term Therapies for Treatment of Acute and Advanced Heart Failure-Why so Few Drugs Available in Clinical Use, Why Even Fewer in the Pipeline?

Both acute and advanced heart failure are an increasing threat in term of survival, quality of life and socio-economical burdens. Paradoxically, the use of successful treatments for chronic heart failure can prolong life but-per definition-causes the rise in age of patients experiencing acute decompensations, since nothing at the moment helps avoiding an acute or final stage in the elderly population. To complicate the picture, acute heart failure syndromes are a collection of symptoms, signs and markers, with different aetiologies and different courses, also due to overlapping morbidities and to the plethora of chronic medications. The palette of cardio- and vasoactive drugs used in the hospitalization phase to stabilize the patient's hemodynamic is scarce and even scarcer is the evidence for the agents commonly used in the practice (e.g. catecholamines). The pipeline in this field is poor and the clinical development chronically unsuccessful. Recent set backs in expected clinical trials for new agents in acute heart failure (AHF) (omecamtiv, serelaxine, ularitide) left a field desolately empty, where only few drugs have been approved for clinical use, for example, levosimendan and nesiritide. In this consensus opinion paper, experts from 26 European countries (Austria, Belgium, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Israel, Italy, The Netherlands, Norway, Poland, Portugal, Russia, Slovenia, Spain, Sweden, Switzerland, Turkey, U.K. and Ukraine) analyse the situation in details also by help of artificial intelligence applied to bibliographic searches, try to distil some lesson-learned to avoid that future projects would make the same mistakes as in the past and recommend how to lead a successful development project in this field in dire need of new agents.

Adrenergic Downregulation in Critical Care: Molecular Mechanisms and Therapeutic Evidence

Catecholamines remain the mainstay of therapy for acute cardiovascular dysfunction. However, adrenergic receptors quickly undergo desensitization and downregulation after prolonged stimulation. Moreover, prolonged exposure to high circulating catecholamines levels is associated with several adverse effects on different organ systems. Unfortunately, in critically ill patients, adrenergic downregulation translates into progressive reduction of cardiovascular response to exogenous catecholamine administration, leading to refractory shock. Accordingly, there has been a growing interest in recent years toward use of noncatecholaminergic inotropes and vasopressors. Several studies investigating a wide variety of catecholamine-sparing strategies (eg, levosimendan, vasopressin, β-blockers, steroids, and use of mechanical circulatory support) have been published recently. Use of these agents was associated with improvement in hemodynamics and decreased catecholamine use but without a clear beneficial effect on major clinical outcomes. Accordingly, additional research is needed to define the optimal management of catecholamine-resistant shock.

Why has positive inotropy failed in chronic heart failure? Lessons from prior inotrope trials

Current pharmacological therapies for heart failure with reduced ejection fraction are largely either repurposed anti‐hypertensives that blunt overactivation of the neurohormonal system or diuretics that decrease congestion. However, they do not address the symptoms of heart failure that result from reductions in cardiac output and reserve. Over the last few decades, numerous attempts have been made to develop and test positive cardiac inotropes that improve cardiac haemodynamics. However, definitive clinical trials have failed to show a survival benefit. As a result, no positive inotrope is currently approved for long‐term use in heart failure. The focus of this state‐of‐the‐art review is to revisit prior clinical trials and to understand the causes for their findings. Using the learnings from those experiences, we propose a framework for future trials of such agents that maximizes their potential for success. This includes enriching the trials with patients who are most likely to derive benefit, using biomarkers and imaging in trial design and execution, evaluating efficacy based on a wider range of intermediate phenotypes, and collecting detailed data on functional status and quality of life. With a rapidly growing population of patients with advanced heart failure, the epidemiologic insignificance of heart transplantation as a therapeutic intervention, and both the cost and morbidity associated with ventricular assist devices, there is an enormous potential for positive inotropic therapies to impact the outcomes that matter most to patients.

Drug Targets for Heart Failure with Preserved Ejection Fraction: A Mechanistic Approach and Review of Contemporary Clinical Trials

Heart failure with preserved ejection fraction (HFpEF) accounts for over half of prevalent heart failure (HF) worldwide, and prognosis after hospitalization for HFpEF remains poor. Due, at least in part, to the heterogeneous nature of HFpEF, drug development has proved immensely challenging. Currently, there are no universally accepted therapies that alter the clinical course of HFpEF. Despite these challenges, important mechanistic understandings of the disease have revealed that the pathophysiology of HFpEF is distinct from that of HF with reduced ejection fraction and have also highlighted potential new therapeutic targets for HFpEF. Of note, HFpEF is a systemic syndrome affecting multiple organ systems. Depending on the organ systems involved, certain novel therapies offer promise in reducing the morbidity of the HFpEF syndrome. In this review, we aim to discuss novel pharmacotherapies for HFpEF based on its unique pathophysiology and identify key research strategies to further elucidate mechanistic pathways to develop novel therapeutics in the future.

Current Status of Inotropes in Heart Failure

Inotropes are medications that improve the contractility of the heart and are used in patients with low cardiac output or evidence of end-organ dysfunction. Since their initial discovery, inotropes have held promise in alleviating symptoms and potentially increasing longevity in such patients. Decades of intensive study have further elucidated the benefits and risks of using inotropes. In this article, the authors discuss the history of inotropes, their indications, mechanism of action, and current guidelines pertaining to their use in heart failure. The authors provide insight into their appropriate use and related shortcomings and the practical aspects of inotrope use.

Altered sarco(endo)plasmic reticulum calcium adenosine triphosphatase 2a content: Targets for heart failure therapy

Sarco(endo)plasmic reticulum calcium adenosine triphosphatase is responsible for transporting cytosolic calcium into the sarcoplasmic reticulum and endoplasmic reticulum to maintain calcium homeostasis. Sarco(endo)plasmic reticulum calcium adenosine triphosphatase is the dominant isoform expressed in cardiac tissue, which is regulated by endogenous protein inhibitors, post-translational modifications, hormones as well as microRNAs. Dysfunction of sarco(endo)plasmic reticulum calcium adenosine triphosphatase is associated with heart failure, which makes sarco(endo)plasmic reticulum calcium adenosine triphosphatase a promising target for heart failure therapy. This review summarizes current approaches to ameliorate sarco(endo)plasmic reticulum calcium adenosine triphosphatase function and focuses on phospholamban, an endogenous inhibitor of sarco(endo)plasmic reticulum calcium adenosine triphosphatase, pharmacological tools and gene therapies.

Istaroxime, a positive inotropic agent devoid of proarrhythmic properties in sensitive chronic atrioventricular block dogs

Current inotropic agents in heart failure therapy associate with low benefit and significant adverse effects, including ventricular arrhythmias. Istaroxime, a novel Na⁺/K⁺-transporting ATPase inhibitor, also stimulates SERCA2a activity, which would confer improved inotropic and lusitropic properties with less proarrhythmic effects. We investigated hemodynamic, electrophysiological and potential proarrhythmic and antiarrhythmic effects of istaroxime in control and chronic atrioventricular block (CAVB) dogs sensitive to drug-induced Torsades de Pointes arrhythmias (TdP). In isolated normal canine ventricular cardiomyocytes, istaroxime (0.3-10 μM) evoked no afterdepolarizations and significantly shortened action potential duration (APD) at 3 and 10 μM. Istaroxime at 3 μg/kg/min significantly increased left ventricular (LV) contractility (dP/dt+) and relaxation (dP/dt-) respectively by 81 and 94% in anesthetized control dogs (n = 6) and by 61 and 49% in anesthetized CAVB dogs (n = 7) sensitive to dofetilide-induced TdP. While istaroxime induced no ventricular arrhythmias in control conditions, only single ectopic beats occurred in 2/7 CAVB dogs, which were preceded by increase of short-term variability of repolarization (STV) and T wave alternans in LV unipolar electrograms. Istaroxime pre-treatment (3 μg/kg/min for 60 min) did not alleviate dofetilide-induced increase in repolarization and STV, and mildly reduced incidence of TdP from 6/6 to 4/6 CAVB dogs. In six CAVB dogs with dofetilide-induced TdP, administration of istaroxime (90 μg/kg/5 min) suppressed arrhythmic episodes in two animals. Taken together, inotropic and lusitropic properties of istaroxime in CAVB dogs were devoid of significant proarrhythmic effects in sensitive CAVB dogs, and istaroxime provides a moderate antiarrhythmic efficacy in prevention and suppression of dofetilide-induced TdP.

Functional characterization and anti-cancer action of the clinical phase II cardiac Na+/K+ ATPase inhibitor istaroxime: in vitro and in vivo properties and cross talk with the membrane androgen receptor

Sodium potassium pump (Na⁺/K⁺ ATPase) is a validated pharmacological target for the treatment of various cardiac conditions. Recent published data with Na⁺/K⁺ ATPase inhibitors suggest a potent anti-cancer action of these agents in multiple indications. In the present study, we focus on istaroxime, a Na⁺/K⁺ ATPase inhibitor that has shown favorable safety and efficacy properties in cardiac phase II clinical trials. Our experiments in 22 cancer cell lines and in prostate tumors in vivo proved the strong anti-cancer action of this compound. Istaroxime induced apoptosis, affected the key proliferative and apoptotic mediators c-Myc and caspase-3 and modified actin cystoskeleton dynamics and RhoA activity in prostate cancer cells. Interestingly, istaroxime was capable of binding to mAR, a membrane receptor mediating rapid, non-genomic actions of steroids in prostate and other cells. These results support a multi-level action of Na⁺/K⁺ ATPase inhibitors in cancer cells and collectively validate istaroxime as a strong re-purposing candidate for further cancer drug development.

Istaroxime, a potential anticancer drug in prostate cancer, exerts beneficial functional effects in healthy and diseased human myocardium

The current gold standard for prostate cancer treatment is androgen deprivation therapy and antiandrogenic agents. However, adverse cardiovascular events including heart failure can limit therapeutic use. Istaroxime, which combines Na⁺-K⁺-ATPase (NKA) inhibition with sarco/endoplasmic reticulum Ca²⁺-ATPase 2a (SERCA2a) stimulation, has recently shown promising anti-neoplastic effects in prostate cancer (PC) models and may also improve cardiac function. Considering the promising anticancer effects of istaroxime, we aimed to assess its functional effects on human myocardium.

Cardiovascular Pharmacology: An Update and Anesthesia Considerations

Cardiovascular disease remains a leading cause of morbidity and mortality worldwide. The development of therapeutic agents for the treatment of cardiovascular diseases has always been a priority because of the huge potential market for these drugs. These medications should be part of the anesthesiologist's armamentarium because the typical surgical patient is older and has more comorbidities than in the past. This article reviews commonly used cardiovascular medications that are important in managing patients with unstable hemodynamics.

Pharmacological reasons that may explain why randomized clinical trials have failed in acute heart failure syndromes

Acute heart failure (AHF) represents a clinical challenge as it encloses a heterogeneous group of syndromes (AHFS) with different pathophysiology, clinical presentations, prognosis and response to therapy. In the last 25years multiple therapeutic targets have been identified and numerous new drugs were evaluated but, up to now, all failed to demonstrate a consistent benefit on clinical outcomes. Moreover, a repeated finding has been the poor correlation between the encouraging results of preclinical and early clinical trials and the lack of effect on outcomes observed in phase III trials. We review several possible pharmacological reasons that may explain the lack of success to develop new drugs and the pharmacological challenges to overcome in the future to develop new more effective and safer drugs for the treatment of AHFS.

Epidemiology, pathophysiology, and in-hospital management of pulmonary edema: data from the Romanian Acute Heart Failure Syndromes registry

AIM

The objective of this study was to evaluate the clinical presentation, inpatient management, and in-hospital outcome of patients hospitalized for acute heart failure syndromes (AHFS) and classified as pulmonary edema (PE).

METHODS

The Romanian Acute Heart Failure Syndromes (RO-AHFS) study was a prospective, national, multicenter registry of all consecutive patients admitted with AHFS over a 12-month period. Patients were classified at initial presentation by clinician-investigators into the following clinical profiles: acute decompensated HF, cardiogenic shock, PE, right HF, or hypertensive HF.

RESULTS

RO-AHFS enrolled 3224 patients and 28.7% (n = 924) were classified as PE. PE patients were more likely to present with pulmonary congestion, tachypnea, tachycardia, and elevated systolic blood pressure and less likely to have peripheral congestion and body weight increases. Mechanical ventilation was required in 8.8% of PE patients. PE patients received higher doses (i.e. 101.4 ± 27.1 mg) of IV furosemide for a shorter duration (i.e. 69.3 ± 22.3 hours). Vasodilators were given to 73.6% of PE patients. In-hospital all-cause mortality (ACM) in PE patients was 7.4%, and 57% of deaths occurred on day one. Increasing age, concurrent acute coronary syndromes, life-threatening ventricular arrhythmias, elevated BUN, left bundle branch block, inotrope therapy, and requirement for invasive mechanical ventilation were independent risk factors for ACM.

CONCLUSIONS

In this national registry, the PE profile was found to be a high-acuity clinical presentation with distinctive treatment patterns and a poor short-term prognosis. Advances in the management of PE may necessitate both the development of novel targeted therapies as well as systems-based strategies to identify high-risk patients early in their course.

Similar hemodynamic decongestion with vasodilators and inotropes: systematic review, meta-analysis, and meta-regression of 35 studies on acute heart failure

BACKGROUND

Acute heart failure (AHF) with reduced left-ventricular ejection fraction (LVEF) is often a biventricular congested state. The comparative effect of vasodilators and inotropes on the right- and/or left-sided congestion is unknown.

METHODS AND RESULTS

A systematic review, meta-analysis, and meta-regression of AHF studies using pulmonary artery catheter were performed using PubMed, Embase, and Cochrane library. Data from 35 studies, including 3016 patients, were studied. Included patients had a weighted mean age of 60 years, left-ventricular ejection fraction (LVEF) of 24 %, and plasma B-type natriuretic peptide (BNP) of 892 pg/ml. Both the left- and right-ventricular filling pressures were elevated: weighted mean pulmonary artery wedge pressure (PAWP) was 25 mmHg (range 17-31 mmHg) and right atrial pressure (RAP) 12 mmHg (range 7-18 mmHg). Vasodilators and inotropes had similar beneficial effects on PAWP [-6.3 mmHg (95 % CI -7.4 to -5.2 mmHg) and -5.8 mmHg (95 % CI -7.6 to -4.0 mmHg), respectively] and RAP [-2.9 mmHg (95 % CI -3.8 to -2.1 mmHg) and -2.8 mmHg (95 % CI -3.8 to -1.7 mmHg), respectively]. Among inotropes, inodilators, such as levosimendan, have greater beneficial effect on the left-ventricular filling pressure than dobutamine. Drug-induced improvement of PAWP tightly paralleled that of RAP with all studied drugs (r ² = 0.90, p < 0.001). Vasodilators and inotropes had no short-term effect of renal function.

CONCLUSION

The left- and right-sided filling pressures are similarly improved by vasodilators or inotropes, in AHF with reduced LVEF.

Outcome of inotropic therapy: is less always more?

PURPOSE OF REVIEW

Positive inotropic agents are widely used in the management of the critical ill patient presenting with low cardiac output state. Different inotropic agents are available, and different effects on hemodynamic endpoints may be recognized, but data on relevant clinical endpoints are scarce. A growing body of literature suggests that overuse of inotropes may have detrimental effects on cardiomyocytes, resulting in an increased risk of morbidity and mortality. The present review will summarize recent literature, focusing on outcome studies among adult patients related to use of inotropes in different clinical settings.

RECENT FINDINGS

Use of inotropic therapy shows a manifold variation between hospitals and individual providers even after risk standardization. No recent studies have shown inotropic therapy to provide short-term and long-term improvement of morbidity and mortality in patients with advanced nonsurgical heart failure or septic shock or as part of goal-directed treatment in high-risk noncardiac surgery. Levosimendan may show beneficial effect on mortality in cardiac surgery.

CONCLUSION

A 'less is more' approach may show to be appropriate when relating to routine use of inotropes. Inotropic therapy should be restricted to patients with heart failure and clinical signs of end-organ hypoperfusion.

Targeting cardiomyocyte Ca2+ homeostasis in heart failure

Improved treatments for heart failure patients will require the development of novel therapeutic strategies that target basal disease mechanisms. Disrupted cardiomyocyte Ca²⁺ homeostasis is recognized as a major contributor to the heart failure phenotype, as it plays a key role in systolic and diastolic dysfunction, arrhythmogenesis, and hypertrophy and apoptosis signaling. In this review, we outline existing knowledge of the involvement of Ca²⁺ homeostasis in these deficits, and identify four promising targets for therapeutic intervention: the sarcoplasmic reticulum Ca²⁺ ATPase, the Na⁺-Ca²⁺ exchanger, the ryanodine receptor, and t-tubule structure. We discuss experimental data indicating the applicability of these targets that has led to recent and ongoing clinical trials, and suggest future therapeutic approaches.

Drug Therapy for Acute Heart Failure

Acute heart failure is globally one of most frequent reasons for hospitalization and still represents a challenge for the choice of the best treatment to improve patient outcome. According to current international guidelines, as soon as patients with acute heart failure arrive at the emergency department, the common therapeutic approach aims to improve their signs and symptoms, correct volume overload, and ameliorate cardiac hemodynamics by increasing vital organ perfusion. Recommended treatment for the early management of acute heart failure is characterized by the use of intravenous diuretics, oxygen, and vasodilators. Although these measures ameliorate the patient's symptoms, they do not favorably impact on short- and long-term mortality. Consequently, there is a pressing need for novel agents in acute heart failure treatment with the result that research in this field is increasing worldwide.