Novel biologic mechanisms of levosimendan and its effect on the failing heart

Repetitive ambulatory levosimendan as a bridge to heart transplantation

INTRODUCTION AND OBJECTIVES

Repetitive ambulatory doses of levosimendan are an option as a bridge to heart transplantation (HT), but evidence regarding the safety and efficacy of this treatment is scarce. The objective of the LEVO-T Registry is to describe the profile of patients on the HT list receiving levosimendan, prescription patterns, and clinical outcomes compared with patients not on levosimendan.

METHODS

We retrospectively reviewed all patients listed for elective HT from 2015 to 2020 from 14 centers in Spain.

RESULTS

A total of 1015 consecutive patients were included, of whom 238 patients (23.4%) received levosimendan. Patients treated with levosimendan had more heart failure (HF) admissions in the previous year and a worse clinical profile. The most frequent prescription pattern were fixed doses triggered by the patients' clinical needs. Nonfatal ventricular arrhythmias occurred in 2 patients (0.8%). No differences in HF hospitalizations were found between patients who started levosimendan in the first 30 days after listing and those who did not (33.6% vs 34.5%; P=.848). Among those who did not, 102 patients (32.9%) crossed over to levosimendan after an HF admission. These patients had a rate of 0.57 HF admissions per month before starting levosimendan and 0.21 afterwards. Propensity score matching analysis showed no differences in survival at 1 year after listing between patients receiving levosimendan and those who did not (HR, 1.03; 95%CI, 0.36-2.97; P=.958) or in survival after HT (HR, 0.97; 95%CI, 0.60-1.56; P=.958).

CONCLUSIONS

Repetitive levosimendan in an ambulatory setting as a bridge to heart transplantation is commonly used, is safe, and may reduce HF hospitalizations.

Safety of Levosimendan in Pediatric Patients: An Up-to-Date Systematic Review

BACKGROUND

The potential risks associated with the use of levosimendan in the pediatric population has not been systematically evaluated. This study aimed to review the available evidence regarding the safety of this treatment.

METHODS

Bio Med Central, PubMed, Embase, and the Cochrane Central Register of clinical trials were searched for studies describing levosimendan administration in the pediatric population in any setting. Relevant studies were independently screened, selected, and their data extracted by two investigators. The authors excluded: reviews, meta-analyses, as well as basic research and trials involving patients >18 years old. The primary outcome was the number and the type of adverse side effects reported during levosimendan administration.

RESULTS

The updated systematic review included 48 studies, enrolling a total of 1,271 pediatric patients who received levosimendan as treatment (790 patients in the 11 studies that reported side effects). The primary adverse effects of levosimendan administration were hypotension and cardiac arrhythmias, particularly tachycardia. Hypotension occurred in approximately 28.9% of patients, while arrhythmia occurred in about 12.3% of patients. Meta analysis of RCTs revealed a rate of all-cause mortality of 2.0% (8 out of 385) in the levosimendan group compared to 3.9% (15 out of 378) in the control group (dobutamine, milrinone or placebo) (risk ratio [RR] = 0.55; 95% confidence interval [CI] = 0.25-1.21; P = 0.14; I2 = 0%) CONCLUSIONS: Hypotension and cardiac arrhythmia are the most reported side effects of levosimendan in pediatric patients. However, adverse events remain underreported, especially in randomized trials.

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.

Cardiac Ischemia On-a-Chip: Antiarrhythmic Effect of Levosimendan on Ischemic Human-Induced Pluripotent Stem Cell-Derived Cardiomyocytes

Ischemic heart disease (IHD) is one of the leading causes of mortality worldwide. Preserving functionality and preventing arrhythmias of the heart are key principles in the management of patients with IHD. Levosimendan, a unique calcium (Ca2+) enhancer with inotropic activity, has been introduced into clinical usage for heart failure treatment. Human-induced pluripotent cell-derived cardiomyocytes (hiPSC-CMs) offer an opportunity to better understand the pathophysiological mechanisms of the disease as well as to serve as a platform for drug screening. Here, we developed an in vitro IHD model using hiPSC-CMs in hypoxic conditions and defined the effects of the subsequent hypoxic stress on CMs functionality. Furthermore, the effect of levosimendan on hiPSC-CMs functionality was evaluated during and after hypoxic stress. The morphology, contractile, Ca2+-handling, and gene expression properties of hiPSC-CMs were investigated in response to hypoxia. Hypoxia resulted in significant cardiac arrhythmia and decreased Ca2+ transient amplitude. In addition, disorganization of sarcomere structure was observed after hypoxia induction. Interestingly, levosimendan presented significant antiarrhythmic properties, as the arrhythmia was abolished or markedly reduced with levosimendan treatment either during or after the hypoxic stress. Moreover, levosimendan presented significant protection from the sarcomere alterations induced by hypoxia. In conclusion, this chip model appears to be a suitable preclinical representation of IHD. With this hypoxia platform, detailed knowledge of the disease pathophysiology can be obtained. The antiarrhythmic effect of levosimendan was clearly observed, suggesting a possible new clinical use for the drug.

Inotropes in Patients with Advanced Heart Failure: Not Only Palliative Care

Patients with advanced heart failure suffer from severe and persistent symptoms, often not responding disease-modifying drugs, a marked limitation of functional capacity and poor quality of life that can ameliorate with inotropic drugs therapy. In small studies, pulsed infusions of classical inotropes (ie, dobutamine and milrinone) are associated with improvement in hemodynamic parameters and quality of life in patients with advanced heart failure. However, because of the adverse effects of these drugs, serious safety issues have been raised. Levosimendan is a calcium-sensitizing inodilators with a triple mechanism of action, whose infusion results in hemodynamic, neurohormonal, and inflammatory cytokine improvements in patients with chronic advanced HF. In addition, levosimendan has important pleiotropic effects, including protection of myocardial, renal, and liver cells from ischemia-reperfusion injury, and anti-inflammatory and antioxidant effects; these properties possibly make levosimendan an "organ protective" inodilator. In clinical trials and real-world evidence, infusion of levosimendan at fixed intervals is safe and effective in patients with advanced HF, alleviating clinical symptoms, reducing hospitalizations, and improving the quality of life. Therefore, the use of repeated doses of levosimendan could represent the therapy of choice as a bridge to transplant/left ventricular assist device implantation or as palliative therapy in patients with advanced heart failure.

The role of levosimendan in phosphine-induced cardiotoxicity: evaluation of electrocardiographic, echocardiographic, and biochemical parameters

Aluminum phosphide (AlP) causes serious poisoning in which severe cardiac suppression is the significant lethal consequence. According to evidence, levosimendan can exert outstanding cardiac support and protection in different pathological conditions. This study aimed to investigate the mechanisms by which levosimendan may alleviate cardiovascular toxicity due to AlP intoxication in the rat model. The groups included control group (normal saline only), sole levosimendan groups (12, 24, 48 μg/kg), AlP group (10 mg/kg), and AlP + levosimendan groups receiving 12, 24, 48 μg/kg levosimendan intraperitoneally 30 min after AlP administration. Electrocardiographic (ECG) parameters (QRS and PR duration and ST height), heart rate, and blood pressure were monitored for 180 minutes. Also, after 24 h of poisoning, echocardiography was applied to assess left ventricle function. Evaluation of the biochemical parameters in heart tissue, including mitochondrial complexes I, II, IV activity, ADP/ATP ratio, the rate of apoptosis, malondialdehyde (MDA), lactate, and troponin I levels, were done after 12 and 24 h. AlP-induced ECG abnormalities (PR duration and ST height), reduction in heart rate, blood pressure, cardiac output, ejection fraction, and stroke volume were improved by levosimendan administration. Besides, levosimendan significantly improved complex IV activity, the ADP/ATP ratio, apoptosis, MDA, lactate, and troponin I level following AlP-poisoning. Our results suggest that levosimendan might alleviate AlP-induced cardiotoxicity by modulating mitochondrial activity and improving cardiac function. However, the potential clinical use of levosimendan in this toxicity needs more investigations.

Mechanisms of Cisplatin-Induced Acute Kidney Injury: Pathological Mechanisms, Pharmacological Interventions, and Genetic Mitigations

Administration of the chemotherapeutic agent cisplatin leads to acute kidney injury (AKI). Cisplatin-induced AKI (CIAKI) has a complex pathophysiological map, which has been linked to cellular uptake and efflux, apoptosis, vascular injury, oxidative and endoplasmic reticulum stress, and inflammation. Despite research efforts, pharmaceutical interventions, and clinical trials spanning over several decades, a consistent and stable pharmacological treatment option to reduce AKI in patients receiving cisplatin remains unavailable. This has been predominately linked to the incomplete understanding of CIAKI pathophysiology and molecular mechanisms involved. Herein, we detail the extensively known pathophysiology of cisplatin-induced nephrotoxicity that manifests and the variety of pharmacological and genetic alteration studies that target them.

Levosimendan prevents doxorubicin-induced cardiotoxicity in time- and dose-dependent manner: implications for inotropy

AIMS

Levosimendan (LEVO) a clinically-used inodilator, exerts multifaceted cardioprotective effects. Case-studies indicate protection against doxorubicin (DXR)-induced cardiotoxicity, but this effect remains obscure. We investigated the effect and mechanism of different regimens of levosimendan on sub-chronic and chronic doxorubicin cardiotoxicity.

METHODS AND RESULTS

Based on preliminary in vivo experiments, rats serving as a sub-chronic model of doxorubicin-cardiotoxicity and were divided into: Control (N/S-0.9%), DXR (18 mg/kg-cumulative), DXR+LEVO (LEVO, 24 μg/kg-cumulative), and DXR+LEVO (acute) (LEVO, 24 μg/kg-bolus) for 14 days. Protein kinase-B (Akt), endothelial nitric oxide synthase (eNOS), and protein kinase-A and G (PKA/PKG) pathways emerged as contributors to the cardioprotection, converging onto phospholamban (PLN). To verify the contribution of PLN, phospholamban knockout (PLN-/-) mice were assigned to PLN-/-/Control (N/S-0.9%), PLN-/-/DXR (18 mg/kg), and PLN-/-/DXR+LEVO (ac) for 14 days. Furthermore, female breast cancer-bearing (BC) mice were divided into: Control (normal saline 0.9%, N/S 0.9%), DXR (18 mg/kg), LEVO, and DXR+LEVO (LEVO, 24 μg/kg-bolus) for 28 days. Echocardiography was performed in all protocols. To elucidate levosimendan's cardioprotective mechanism, primary cardiomyocytes were treated with doxorubicin or/and levosimendan and with N omega-nitro-L-arginine methyl ester (L-NAME), DT-2, and H-89 (eNOS, PKG, and PKA inhibitors, respectively); cardiomyocyte-toxicity was assessed. Single bolus administration of levosimendan abrogated DXR-induced cardiotoxicity and activated Akt/eNOS and cAMP-PKA/cGMP-PKG/PLN pathways but failed to exert cardioprotection in PLN-/- mice. Levosimendan's cardioprotection was also evident in the BC model. Finally, in vitro PKA inhibition abrogated levosimendan-mediated cardioprotection, indicating that its cardioprotection is cAMP-PKA dependent, while levosimendan preponderated over milrinone and dobutamine, by ameliorating calcium overload.

CONCLUSION

Single dose levosimendan prevented doxorubicin cardiotoxicity through a cAMP-PKA-PLN pathway, highlighting the role of inotropy in doxorubicin cardiotoxicity.

Inotropes in Acute Heart Failure: From Guidelines to Practical Use: Therapeutic Options and Clinical Practice

Inotropes are pharmacological agents that are indicated for the treatment of patients presenting with acute heart failure (AHF) with concomitant hypoperfusion due to decreased cardiac output. They are usually administered for a short period during the initial management of AHF until haemodynamic stabilisation and restoration of peripheral perfusion occur. They can be used for longer periods to support patients as a bridge to a more definite treatment, such as transplant of left ventricular assist devices, or as part of a palliative care regimen. The currently available inotropic agents in clinical practice fall into three main categories: beta-agonists, phosphodiesterase III inhibitors and calcium sensitisers. However, due to the well-documented potential for adverse events and their association with increased long-term mortality, physicians should be aware of the indications and dosing strategies suitable for different types of patients. Novel inotropes that use alternative intracellular pathways are under investigation, in an effort to minimise the drawbacks that conventional inotropes exhibit.

A randomized controlled trial of levosimendan to reduce mortality in high-risk cardiac surgery patients (CHEETAH): Rationale and design

OBJECTIVE

Patients undergoing cardiac surgery are at risk of perioperative low cardiac output syndrome due to postoperative myocardial dysfunction. Myocardial dysfunction in patients undergoing cardiac surgery is a potential indication for the use of levosimendan, a calcium sensitizer with 3 beneficial cardiovascular effects (inotropic, vasodilatory, and anti-inflammatory), which appears effective in improving clinically relevant outcomes.

DESIGN

Double-blind, placebo-controlled, multicenter randomized trial.

SETTING

Tertiary care hospitals.

INTERVENTIONS

Cardiac surgery patients (n = 1,000) with postoperative myocardial dysfunction (defined as patients with intraaortic balloon pump and/or high-dose standard inotropic support) will be randomized to receive a continuous infusion of either levosimendan (0.05-0.2 μg/[kg min]) or placebo for 24-48 hours.

MEASUREMENTS AND MAIN RESULTS

The primary end point will be 30-day mortality. Secondary end points will be mortality at 1 year, time on mechanical ventilation, acute kidney injury, decision to stop the study drug due to adverse events or to start open-label levosimendan, and length of intensive care unit and hospital stay. We will test the hypothesis that levosimendan reduces 30-day mortality in cardiac surgery patients with postoperative myocardial dysfunction.

CONCLUSIONS

This trial is planned to determine whether levosimendan could improve survival in patients with postoperative low cardiac output syndrome. The results of this double-blind, placebo-controlled randomized trial may provide important insights into the management of low cardiac output in cardiac surgery.

Ischemia-modified albumin levels in patients with acute decompensated heart failure treated with dobutamine or levosimendan: IMA-HF study

OBJECTIVE

Ischemia-modified albumin (IMA) is a sensitive biomarker of myocardial ischemia. However, data on IMA levels in acute heart failure (HF) are still lacking. In this study, we aimed to evaluate serum IMA levels in acute decompensated HF and the effects of dobutamine and levosimendan treatments on IMA levels.

METHODS

This was a prospective, multicenter study that included 70 patients hospitalized with acute decompensated HF and left ventricular ejection fraction < 35%. Blood samples for IMA measurements were obtained on admission and 24-48 h after the initiation of HF therapy. Twenty-nine patients were treated with standard HF therapy, 18 received levosimendan, and 23 received dobutamine in addition to standard of care. A single serum specimen was also collected from 32 healthy individuals each. IMA concentrations were measured by the albumin cobalt binding colorimetric assay, and the results were given in absorbance units (AU). Independent and paired sample t-tests, Mann-Whitney U test, and Wilcoxon signed-rank test were used for the analysis.

RESULTS

In patients with acute decompensated HF, the serum concentration of IMA was significantly higher than those of healthy subjects (0.894 ± 0.23 AU vs. 0.379 ± 0.08 AU, p < 0.001). Overall, the IMA levels significantly decreased after 24-48 h of HF therapy (0.894 ± 0.23 AU and 0.832 ± 0.18 AU, p = 0.013). Furthermore, the IMA levels were also found to significantly decrease with standard HF therapy (1.041 ± 0.28 vs. 0.884 ± 0.15 AU, p = 0.041), with levosimendan (0.771 ± 0.18 vs. 0.728 ± 0.18 AU, p = 0.046) and also with dobutamine (0.892 ± 0.18 vs. 0.820 ± 0.13 AU, p = 0.035).

CONCLUSION

Patients with acute decompensated HF had elevated IMA levels, and appropriate HF therapy significantly reduced the serum IMA levels. Dobutamine or levosimendan did not increase the IMA levels, suggesting a lower potential in inducing myocardial ischemia when used in recommended doses.

Levosimendan displays anti-inflammatory effects and decreases MPO bioavailability in patients with severe heart failure

Treatment of decompensated heart failure often includes administration of levosimendan. Myeloperoxidase (MPO) is released during polymorphonuclear neutrophil (PMN) degranulation, and mediates dysregulation of vascular tone in heart failure. We evaluated the effects of levosimendan-treatment on MPO in patients with acute decompensation of chronic heart failure over a one week course. Plasma MPO levels were significantly decreased after levosimendan treatment (from 252.1 ± 31.1 pmol/l at baseline to 215.02 ± 27.96 pmol/l at 6 h, p < 0.05). Ex vivo incubation of whole blood with levosimendan decreased MPO release after PMN-stimulation (8.2 ± 1.4-fold increase at baseline vs. 6.0 ± 1.1-fold increase with levosimendan). MPO levels also significantly correlated with diastolic blood pressure over the time course. In a multivariate linear model, the main contributor to systolic, diastolic and mean blood pressure was level of PMN elastase. MPO contributed only in heparin-treated patients, suggesting a more significant role for endothelial-bound MPO than for circulating MPO or elastase with respect to blood pressure regulation. We here provide the first evidence that levosimendan treatment inhibits MPO release by PMNs in decompensated heart failure patients. This mechanism may regulate endothelial function and vascular tone in heart failure patients.

Impact of levosimendan on brain injury patterns in a lamb model of infant cardiopulmonary bypass

BACKGROUND

The effects of levosimendan (Levo) on injury patterns in the immature brain following cardiopulmonary bypass (CPB) are unknown.

METHODS

Eighteen 3- to 4-wk-old anesthetized lambs, instrumented with vascular catheters and aortic and right carotid artery flow probes, were allocated to non-CPB, CPB, or CPB+Levo groups (each n = 6). After 120 min CPB with 90 min aortic cross-clamp, CPB animals received dopamine, and CPB+Levo animals both dopamine and Levo, for 4 h. All lambs then underwent brain magnetic resonance imaging, followed by postmortem brain perfusion fixation for immunohistochemical studies.

RESULTS

In CPB lambs, aortic (P < 0.05) and carotid artery (P < 0.01) blood flows fell by 29 and 30%, respectively, between 2 and 4 h after cross-clamp removal but were unchanged in the CPB+Levo group. No brain injury was detectable with magnetic resonance imaging in either CPB or CPB+Levo lambs. However, on immunohistochemical analysis, white matter astrocyte density of both groups was higher than in non-CPB lambs (P < 0.05), while white matter microglial density was higher (P < 0.05), but markers of cortical oxidative stress were less prevalent in CPB+Levo than CPB lambs.

CONCLUSION

While Levo prevented early postoperative falls in cardiac output and carotid artery blood flow in a lamb model of infant CPB, this was associated with heterogeneous neuroglial activation and manifestation of markers of oxidative stress.

Efficacy and safety of the pulsed infusions of levosimendan in outpatients with advanced heart failure (LevoRep) study: a multicentre randomized trial

AIMS

The aim of this study was to determine whether intermittent ambulatory treatment with levosimendan would improve functional capacity, quality of life, and event-free survival in patients with advanced heart failure.

METHODS AND RESULTS

This was a prospective, randomized, double-blind, placebo-controlled, multicentre, parallel-group trial of pulsed infusions of levosimendan in 120 outpatients with advanced heart failure (EF ≤35%, NYHA class III or IV). The study was conducted at 11 centres in Austria, Greece, and Germany. Levosimendan (0.2 µg/kg/min) or placebo was administered for 6 h at 2-week intervals over 6 weeks, in addition to standard care therapy. The primary outcome was the proportion of patients with a ≥20% improvement in the 6 min walk test and a ≥15% score increase on the Kansas City Cardiomyopathy Questionnaire at the end of the 24-week study period. Secondary outcomes included event-free survival after 24 weeks. Analyses were performed on an intention-to-treat basis. The primary endpoint was reached in 19% of patients receiving levosimendan and 15.8% of patients receiving placebo (odds ratio 1.25; 95% confidence interval 0.44-3.59; P = 0.810). Cardiac death (four vs. one), heart transplants (two vs. one), and acute heart failure (14 vs. nine) were more frequent with placebo as compared with levosimendan. The incidence of side effects was comparable between groups.

CONCLUSION

Intermittent ambulatory treatment with levosimendan in patients with advanced heart failure did not improve significantly functional capacity or quality of life as compared with placebo. An adequately powered, event-driven trial is warranted to enlarge on our findings.

TRIAL REGISTRATION

NCT01065194.

Determination of piperphentonamine and metabolites M1 and M6 in human plasma and urine by LC/MS/MS and its application in a pharmacokinetics study in Chinese healthy volunteers

Piperphentonamine hydrochloride (PPTA) is a new calcium sensitizer. A liquid chromatography-tandem mass spectrometry (LC/MS/MS) method for determination of piperphentonamine and its metabolites M1 and M6 was developed for the first time and applied to a pharmacokinetics study. Protein precipitation was used for pre-treatment of plasma samples, and solid phase extraction method was used for pre-treatment of urine samples. The chromatographic separation was achieved on a C(18) column using gradient elution in this study: A: 1% acetic acid aqueous solution, and B: acetonitrile. The whole analysis lasted for 10.5min and the gradient flow rate was 0.25mL/min constantly. The detection was performed of a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via a positive electrospray ionization source. The results were that the m/z ratios of monitored precursor ions and product ions of PPTA, M1 and M6 were 354.0→191.8, 356.0→148.7 and 358.0→148.7, respectively. From the standard curve, the concentration ranges of both PPTA and M1 in blood and urine samples were 0.1-500ng/mL and 0.1-200ng/mL, respectively; the concentration ranges of M6 in blood sample and urine sample were 0.2-500ng/mL and 0.2-200ng/mL, respectively; and the correlation coefficient of standard curve was r>0.99. A total of 31 healthy Chinese subjects participated in the pharmacokinetic study of single bolus intravenous injection of piperphentonamine hydrochloride. They were divided into three dosage groups and given 0.2, 0.4 and 0.6mg/kg of PPTA. After drug administration, concentrations of PPTA, M1 and M6 in human plasma and urine samples were determined to evaluation the pharmacokinetic characteristics of PPTA and its metabolites M1 and M6.

Treating volume overload in acutely decompensated heart failure: established and novel therapeutic approaches

BACKGROUND

Most patients hospitalized for acutely decompensated heart failure (ADHF) present with symptoms and signs of volume overload, which is also associated with substantially high rates of death and rehospitalization in ADHF.

OBJECTIVE

To review the recent experimental and clinical evidence on existing therapeutic algorithms and investigational drugs used for the treatment of volume overload in ADHF patients.

METHODS

A systematic search of peer-reviewed publications was performed on Medline and EMBASE from January 1990 to March 2012. The results of unpublished trials were obtained from presentations at national and international meetings.

RESULTS

Apart from intrinsic renal insufficiency and neurohormonal activation, volume overload through venous congestion may be the primary haemodynamic factor triggering the worsening of renal function in ADHF patients. It is well known that heart and kidneys are closely interrelated and an acute or chronic disorder in one organ may induce acute or chronic dysfunction in the other organ. Established therapeutic strategies, (e.g. loop diuretics, vasodilators, and inotropes), are sometimes associated with limited clinical success due to tolerance and the need for frequent up titration of the doses in order to achieve the desired effect. That leads to an increasing interest in novel options, such as the use of adenosine A1 receptor antagonists, vasopressin antagonists, and renal-protective dopamine. Initial clinical trials have shown quite encouraging results in some heart failure subpopulations but have failed to demonstrate a clear beneficial role of these agents. On the other hand, ultrafiltration appears to be a more promising therapeutic procedure that will improve volume regulation, while preserving renal and cardiac function.

CONCLUSION

Further clinical studies are required in order to determine their net effect on renal function and potential cardiovascular outcomes. Until then, management of volume overload in ADHF patients remains a challenge for the clinicians.

Chronic heart failure: current evidence, challenges to therapy, and future directions

Heart failure (HF) is a complex syndrome characterized by the inability of the heart to maintain a normal cardiac output without elevated intracardiac filling pressures, resulting in signs of pulmonary and peripheral edema and symptoms of dyspnea and fatigue. Central to the management of HF is a multifaceted pharmacological intervention to abate the harmful counter-regulatory effects of neurohormonal activation and avid salt and water retention. Whereas up to 40 years ago HF was managed with diuretics and leaf of digitalis, the cornerstones of therapy for HF patients with systolic dysfunction now include ACE inhibitors or angiotensin II type 1 receptor antagonists (angiotensin receptor blockers), β-adrenoceptor antagonists (β-blockers), and aldosterone antagonists, which have significantly improved survival. However, with the increasing number of beneficial therapies, there are challenges to implementing all of them. Specific cardiomyopathies also merit specific considerations with respect to treatment, and - unfortunately - there is no therapy for HF with preserved left ventricular ejection fraction that has been shown to improve survival. Although mortality has improved in HF, the biggest challenge to treatment lies in addressing the morbidity of this disease, which is now the most common reason for hospital admission in our aged population. As such, there are many therapies that may serve to improve the quality of life of HF patients. Future HF treatment regimens may include direct cellular therapy via hormone and cytokine signaling or cardiac regeneration through growth factors or cell therapy.

In vivo and in vitro evidence for pleiotropic effects of levosimendan in the intensive care setting

Levosimendan, in addition to its inotropic properties, could have anti-inflammatory and anti-oxidative properties, and can potentially decrease the deleterious effects of reactive oxygen species on the tissues. In their study, Hasslacher and colleagues provided not only in vitro but also in vivo evidence that levosimendan could preserve organ function in acute heart failure and septic-shock-induced myocardial depression via cooling down the oxidative burst of circulating cells.

Levosimendan inhibits release of reactive oxygen species in polymorphonuclear leukocytes in vitro and in patients with acute heart failure and septic shock: a prospective observational study

Introduction

Levosimendan is an extensively investigated inodilator showing also cardioprotective and antiinflammatory effects. The aim of our study was to explore the influence of levosimendan on polymorphonuclear leucocytes (PMN), a main source of reactive oxygen species, in vitro and in patients with acute heart failure or septic myocardial depression.

Methods

PMN isolated from healthy volunteers were incubated with levosimendan in vitro. After stimulation with N-formyl-Met-Leu-Phe (fMLP) or phorbol 12-myristate 13-acetate (PMA) respiratory burst was quantified using a fluorescent dye. Apoptosis and expression of cell adhesion molecules of PMN were measured by flow cytometry. For determination of in vivo effects patients with acute heart failure (n = 16) or septic cardiac failure (n = 9) receiving levosimendan treatment were enrolled consecutively. PMN were isolated to measure respiratory burst activity before treatment as well as one and two hours after initiation of levosimendan administration. Furthermore inflammatory, hemodynamic and renal function parameters were obtained.

Results

In vitro, levosimendan suppressed respiratory burst activity in fMLP or PMA stimulated PMN in a dose dependent manner by 30 ± 11% (P < 0.001) at 100 ng/mL and by 27 ± 17% (P < 0.001) at 1000 ng/mL respectively. Markers of apoptosis and PMN cell adhesion molecule expression remained unaffected by levosimendan treatment.

In vivo, levosimendan treatment for two hours resulted in a significant reduction of PMA stimulated oxidative burst by 45% (P < 0.01) and fMLP stimulated oxidative burst by 49% (P < 0.05) in patients with acute heart failure. In patients suffering from septic shock levosimendan treatment decreased oxidative burst activity in unstimulated, fMLP and PMA stimulated PMN by 48% (P < 0.05), 46% (P < 0.01) and 43% (P < 0.01) respectively.

Conclusions

Levosimendan appears to exert distinct immunomodulatory effects by decreasing oxidative burst activity of PMN. This property might contribute to the previously described cardioprotective effects of the drug.

Effects of levosimendan/furosemide infusion on plasma brain natriuretic peptide, echocardiographic parameters and cardiac output in end-stage heart failure patients

BACKGROUND

Acute decompensation heart failure (ADHF) remains a cause of hospitalization in patients with end-stage congestive HF. The administration of levosimendan in comparison with a standard therapy in CHF patients admitted for ADHF was analysed.

MATERIAL/METHODS

Consecutive patients admitted for ADHF (NYHA class III-IV) were treated with levosimendan infusion 0.1 µg/kg/min or with furosemide infusion 100-160 mg per day for 48 hours (control group). All subjects underwent determination of brain natriuretic peptide (BNP), non-invasive cardiac output (CO), and echocardiogram at baseline, at the end of therapy and 1 week after therapy.

RESULTS

Seven patients admitted for 20 treatments in 16 months (age 66 years; mean admission/year 5.4) were treated with levosimendan and compared with 7 patients admitted for 15 treatments (age 69.1 years; mean admission/year 6.1). At the end of levosimendan therapy, BNP decreased (from 679.7 ± 512.1 pg/ml to 554.2 ± 407.6 pg/ml p = 0.03), and 6 MWT and LVEF improved (from 217.6 ± 97.7 m to 372.2 ± 90.4 m p = 0.0001; from 22.8 ± 9.1% to 25.4 ± 9.8% p = 0.05). Deceleration time, E/A, E/E', TAPSE, pulmonary pressure and CO did not change significantly after levosimendan therapy and after 1 week. At follow-up, only 6-min WT and NYHA class showed a significant improvement (p = 0.0001, p = 0.001 respectively). The furosemide infusion reduced NYHA class and body weight (from 3.4 ± 0.6 to 2.3 ± 0.5 p = 0.001; from 77.5 ± 8.6 kg to 76 ± 6.6 kg p = 0.04), but impaired renal function (clearances from 56.3 ± 21.9 ml/min to 41.2 ± 10.1 ml/min p = 0.04).

CONCLUSIONS

Treating end-stage CHF patients with levosimendan improved BNP and LVEF, but this effect disappeared after 1 week. The amelioration of 6 MWT and NYHA class lasted longer after levosimendan infusion.

Polymorphisms in NAT2 gene and atherosclerosis in an Algerian population

BACKGROUND AND AIMS

The etiology of atherosclerosis is multifactorial. Genetic and environmental factors are involved in the development of atherosclerosis. Human arylamine N-acetyltransferase 2 (NAT2) is an important metabolizing enzyme that exhibits genetic polymorphisms and modifies individual response and/or toxicity to many xenobiotics. We undertook this study to investigate the NAT2 polymorphisms in patients with atherosclerosis.

METHODS

Genotyping for NAT2 alleles was performed using polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) in 285 Algerian patients with atherosclerosis and 286 controls.

RESULTS

There was no association between NAT2 polymorphisms and atherosclerosis risk. However, the haplotype NAT2(*)5F decreased susceptibility to the disease (p = 0.005, OR = 0.55, 95% CI = 0.37-0.84). The frequency of the slow acetylator phenotype was approximately 50% in both cases and controls.

CONCLUSIONS

These results suggest that NAT2 polymorphisms may not be involved in the pathogenesis of atherosclerosis.