Levosimendan, a novel Ca2+ sensitizer, activates the glibenclamide-sensitive K+ channel in rat arterial myocytes

Enhancing Urological Cancer Treatment: Leveraging Vasodilator Synergistic Potential with 5-FU for Improved Therapeutic Outcomes

Backgroud: This study investigates the potential of vasodilator drugs as additive therapy in the treatment of urological cancers, particularly in combination with the antineoplastic agent 5-fluorouracil (5-FU). Methods: The study evaluated the cytotoxic effects of sildenafil, tezosentan and levosimendan alone and in combination with 5-FU on urological cancer cell lines. The assessment included MTT assays, colony formation assays and wound healing assays to determine cell viability, proliferative capacity, and migratory behavior, respectively. Results: Sildenafil and tezosentan showed limited cytotoxic effects, while levosimendan demonstrated moderate anticancer activity. The combination of levosimendan and 5-FU exhibited an additive interaction, enhancing cytotoxicity against cancer cells while sparing normal cells. Levosimendan also inhibited cell migration and proliferation, potentially through mechanisms involving the modulation of cAMP levels and nitric oxide production. Conclusions: The findings suggest that levosimendan can be used in conjunction with 5-FU to reduce the required dose of 5-FU, thereby minimizing side effects without compromising therapeutic efficacy. This study offers a new perspective for enhancing therapeutic outcomes in patients with urological cancers.

Cardiac Troponin Activator Increases Cardiac Contractility in Rats

Novel cardiac troponin activators were identified using a high throughput cardiac myofibril ATPase assay and confirmed using a series of biochemical and biophysical assays. HTS hit 2 increased rat cardiomyocyte fractional shortening without increasing intracellular calcium concentrations, and the biological target of 1 and 2 was determined to be the cardiac thin filament. Subsequent optimization to increase solubility and remove PDE-3 inhibition led to the discovery of CK-963 and enabled pharmacological evaluation of cardiac troponin activation without the competing effects of PDE-3 inhibition. Rat echocardiography studies using CK-963 demonstrated concentration-dependent increases in cardiac fractional shortening up to 95%. Isothermal calorimetry studies confirmed a direct interaction between CK-963 and a cardiac troponin chimera with a dissociation constant of 11.5 ± 3.2 μM. These results provide evidence that direct activation of cardiac troponin without the confounding effects of PDE-3 inhibition may provide benefit for patients with cardiovascular conditions where contractility is reduced.

Levosimendan and Dobutamin Attenuate LPS-Induced Inflammation in Microglia by Inhibiting the NF-κB Pathway and NLRP3 Inflammasome Activation via Nrf2/HO-1 Signalling

Hypovolemic shock is a circulatory failure, due to a loss in the effective circulating blood volume, that causes tissue hypoperfusion and hypoxia. This condition stimulates reactive oxygen species (ROS) and pro-inflammatory cytokine production in different organs and also in the central nervous system (CNS). Levosimendan, a cardioprotective inodilator, and dobutamine, a β1-adrenergic agonist, are commonly used for the treatment of hypovolemic shock, thanks to their anti-inflammatory and antioxidant effects. For this reason, we aimed at investigating levosimendan and dobutamine's neuroprotective effects in an "in vitro" model of lipopolysaccharide (LPS)-induced neuroinflammation. Human microglial cells (HMC3) were challenged with LPS (0.1 µg/mL) to induce an inflammatory phenotype and then treated with levosimendan (10 µM) or dobutamine (50 µM) for 24 h. Levosimendan and dobutamine significantly reduced the ROS levels and markedly increased Nrf2 and HO-1 protein expression in LPS-challenged cells. Levosimendan and dobutamine also decreased p-NF-κB expression and turned off the NLRP3 inflammasome together with its downstream signals, caspase-1 and IL-1β. Moreover, a reduction in TNF-α and IL-6 expression and an increase in IL-10 levels in LPS-stimulated HMC3 cells was observed following treatment. In conclusion, levosimendan and dobutamine attenuated LPS-induced neuroinflammation through NF-κB pathway inhibition and NLRP3 inflammasome activation via Nrf2/HO-1 signalling, suggesting that these drugs could represent a promising therapeutic approach for the treatment of neuroinflammation consequent to hypovolemic shock.

Effects of levosimendan on the outcome of veno-arterial extracorporeal membrane oxygenation: a systematic review and meta-analysis

OBJECTIVES

For patients with severe cardiopulmonary failure, such as cardiogenic shock, veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is primarily utilized to preserve their life by providing continuous extracorporeal respiration and circulation. However, because of the complexity of patients' underlying diseases and serious complications, successful weaning from ECMO is often difficult. At present, there have been limited studies on ECMO weaning strategies, so the principal purpose of this meta-analysis is to examine how levosimendan contributes to the weaning of extracorporeal membrane oxygenation.

METHODS

The Cochrane Library, Embase, Web of Science, and PubMed were browsed for all potentially related research about clinical benefits of levosimendan in weaning patients receiving VA-ECMO and included 15 of them. The main outcome is success of weaning from extracorporeal membrane oxygenation, with the secondary outcomes of 1-month mortality (28 or 30 days), ECMO duration, hospital or intensive care unit (ICU) length of stay, and use of vasoactive drugs.

RESULTS

1772 patients altogether from 15 publications were incorporated in our meta-analysis. We used fixed and random-effect models to combine odds ratio (OR) and 95% confidence interval (CI) for dichotomous outcomes and standardized mean difference (SMD) for continuous outcomes. The weaning success rate in the levosimendan group was considerably higher in contrast to the comparison (OR = 2.78, 95% CI 1.80-4.30; P < 0.00001; I2 = 65%), and subgroup analysis showed that there was less heterogeneity in patients after cardiac surgery (OR = 2.06, 95% CI, 1.35-3.12; P = 0.0007; I2 = 17%). In addition, the effect of levosimendan on improving weaning success rate was statistically significant only at 0.2 mcg/kg/min (OR = 2.45, 95% CI, 1.11-5.40; P = 0.03; I2 = 38%). At the same time, the 28-day or 30-day proportion of deaths in the sample receiving levosimendan also decreased (OR = 0.47, 95% CI, 0.28-0.79; P = 0.004; I2 = 73%), and the difference was statistically significant. In terms of secondary outcomes, we found that individuals undergoing levosimendan treatment had a longer duration of VA-ECMO support.

CONCLUSIONS

In patients receiving VA-ECMO, levosimendan treatment considerably raised the weaning success rate and helped lower mortality. Since most of the evidence comes from retrospective studies, more randomized multicenter trials are required to verify the conclusion.

In silico study of the mechanisms of hypoxia and contractile dysfunction during ischemia and reperfusion of hiPSC cardiomyocytes

Interconnected mechanisms of ischemia and reperfusion (IR) has increased the interest in IR in vitro experiments using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). We developed a whole-cell computational model of hiPSC-CMs including the electromechanics, a metabolite-sensitive sarcoplasmic reticulum Ca2+-ATPase (SERCA) and an oxygen dynamics formulation to investigate IR mechanisms. Moreover, we simulated the effect and action mechanism of levosimendan, which recently showed promising anti-arrhythmic effects in hiPSC-CMs in hypoxia. The model was validated using hiPSC-CM and in vitro animal data. The role of SERCA in causing relaxation dysfunction in IR was anticipated to be comparable to its function in sepsis-induced heart failure. Drug simulations showed that levosimendan counteracts the relaxation dysfunction by utilizing a particular Ca2+-sensitizing mechanism involving Ca2+-bound troponin C and Ca2+ flux to the myofilament, rather than inhibiting SERCA phosphorylation. The model demonstrates extensive characterization and promise for drug development, making it suitable for evaluating IR therapy strategies based on the changing levels of cardiac metabolites, oxygen and molecular pathways.

Efficacy and safety of levosimendan in patients with sepsis: a systematic review and network meta-analysis

Objective: We conducted a systematic review to assess the advantages and disadvantages of levosimendan in patients with sepsis compared with placebo, milrinone, and dobutamine and to explore the clinical efficacy of different concentrations of levosimendan. Methods: PubMed, Web of Science, Cochrane Library, Embase, CNKI, Wanfang data, VIP, and CBM databases were searched using such keywords as simendan, levosimendan, and sepsis. The search time was from the establishment of the database to July 2023. Two researchers were responsible for literature screening and data collection respectively. After the risk of bias in the included studies was evaluated, network meta-analysis was performed using R software gemtc and rjags package. Results: Thirty-two randomized controlled trials (RCTs) were included in the network meta-analysis. Meta-analysis results showed that while levosimendan significantly improved CI levels at either 0.1 µg/kg/min (mean difference [MD] [95%CrI] = 0.41 [-0.43, 1.4]) or 0.2 µg/kg/min (MD [95%CrI] =0.54 [0.12, 0.99]). Levosimendan, at either 0.075 µg/kg/min (MD [95% CrI] =0.033 [-0.75, 0.82]) or 0.2 µg/kg/min (MD [95% CrI] = -0.014 [-0.26, 0.23]), had no significant advantage in improving Lac levels. Levosimendan, at either 0.1 µg/kg/min (RR [95% CrI] = 0.99 [0.73, 1.3]) or 0.2 µg/kg/min (RR [95% CrI] = 1.0 [0.88, 1.2]), did not have a significant advantage in reducing mortality. Conclusion: The existing evidence suggests that levosimendan can significantly improve CI and lactate levels in patients with sepsis, and levosimendan at 0.1 µg/kg/min might be the optimal dose. Unfortunately, all interventions in this study failed to reduce the 28-day mortality. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023441220.

Understanding the Clinical Use of Levosimendan and Perspectives on its Future in Oncology

Drug repurposing, also known as repositioning or reprofiling, has emerged as a promising strategy to accelerate drug discovery and development. This approach involves identifying new medical indications for existing approved drugs, harnessing the extensive knowledge of their bioavailability, pharmacokinetics, safety and efficacy. Levosimendan, a calcium sensitizer initially approved for heart failure, has been repurposed for oncology due to its multifaceted pharmacodynamics, including phosphodiesterase 3 inhibition, nitric oxide production and reduction of reactive oxygen species. Studies have demonstrated that levosimendan inhibits cancer cell migration and sensitizes hypoxic cells to radiation. Moreover, it exerts organ-protective effects by activating mitochondrial potassium channels. Combining levosimendan with traditional anticancer agents such as 5-fluorouracil (5-FU) has shown a synergistic effect in bladder cancer cells, highlighting its potential as a novel therapeutic approach. This drug repurposing strategy offers a cost-effective and time-efficient solution for developing new treatments, ultimately contributing to the advancement of cancer therapeutics and improved outcomes for patients. Further investigations and clinical trials are warranted to validate the effectiveness of levosimendan in oncology and explore its potential benefits in a clinical setting.

Prophylactic use of levosimendan in preoperative setting for surgical repair of congenital heart disease in children

Introduction

Low cardiac output syndrome (LCOS) is a significant cause of morbidity and the leading cause of mortality after pediatric cardiac surgery. Levosimendan has been shown safe and effective in pediatrics to treat LCOS. We aimed to review our local strategy with preoperative prophylactic Levosimendan infusion to minimize LCOS after heart surgery in identified high-risk patients.

Methods

Retrospective monocentric study. As there is no reliable cardiac output measurement in children, we recorded hemodynamic parameters as surrogates of cardiac output after extracorporeal circulation through an electronic patient survey system at different time points.

Results

Seventy-two children received Levosimendan before surgery between 2010 and 2019. As expected, most patients were newborns and infants with prolonged open-heart surgeries. Median cardiopulmonary bypass time was 182 [137-234] min, and aortic clamping time was 95 [64-126] min. The postoperative hemodynamic parameters, vasoactive-inotropic score, and urine output remained stable throughout the first 48 h. Only a tiny portion of the patients had combined surrogate markers of LCOS with a maximal median arterial lactate of 2.6 [1.9-3.5] mmol/L during the first six postoperative hours, which then progressively normalized. The median arterio-venous difference in oxygen saturation was 31 [23-38] % between 12 and 18 h post-surgery and gradually decreased. The median venous-to-arterial CO2 difference was the highest at 10 [7-12] mmHg between 12 and 18 h post-surgery. Nine patients (13%) required extracorporeal membrane oxygenation. No patient required dialysis or hemofiltration. Mortality was 0%.

Conclusion

Before congenital heart surgery, preoperative prophylactic administration of Levosimendan seems effective and safe for decreasing occurrence and duration of LCOS in high-risk children.

Levosimendan in the Treatment of Patients with Severe Septic Cardiomyopathy

(1) Background: The optimal treatment of septic cardiomyopathy (SCM) remains questionable. The aim of the study was to compare the treatment of SCM based on levosimendan versus the best available therapy. (2) Methods: We conducted an observational study including patients with severe septic cardiomyopathy and circulatory failure. (3) Results: Fourteen patients (61%) received levosimendan, and nine received other treatments. The patients in the levosimendan group were more severely ill [APACHE II: 23.5 (14, 37) vs. 14 (13, 28), respectively, p = 0.012], and there was a trend for more decompensated LV function depicted by the LVEF [15% (10, 20) vs. 25% (5, 30), respectively, p = 0.061]. However, they presented a significantly higher increase in LVEF after seven days [15% (10, 20) to 50% (30, 68) (p < 0.0001) vs. 25% (5, 30) to 25% (15, 50) (p = 0.309), and a significantly higher decrease in lactate levels during the first 24 h [4.5 (2.5, 14.4) to 2.85 (1.2, 15), p = 0.036 vs. 2.9 (2, 18.9) to 2.8 (1, 15), p = 0.536]. Seven-day survival (64.3% vs. 33.3%, p = 0.424) and ICU survival (50% vs. 22.2%, p = 0.172) were higher in the first group, although differences did not reach statistical significance. The degree of left ventricular impairment and the magnitude of EF improvement by the seventh-day post-SCM onset were associated with mortality in regression analysis. (4) Conclusions: Our study presents main hemodynamic data supporting the possible efficacy of levosimendan treatment in patients with severe SCM.

The Effects of the Levosimendan Metabolites OR-1855 and OR-1896 on Endothelial Pro-Inflammatory Responses

The calcium sensitizer levosimendan is used for the treatment of acute decompensated heart failure. A small portion (4–7%) of levosimendan is metabolized to the pharmacologically active metabolite OR-1896 via the inactive intermediate OR-1855. In addition, levosimendan has been shown to exert positive effects on the endothelium in vitro antagonizing vascular dysfunction and inflammation. However, the function of the levosimendan metabolites within this context is still unknown. In this study, we thus investigated the impact of the metabolites OR-1896 and OR-1855 on endothelial inflammatory processes in vitro. We observed a reduction of IL-1β-dependent endothelial adhesion molecule ICAM-1 and VCAM-1 as well as interleukin (IL) -6 expression upon levosimendan treatment but not after treatment with OR-1855 or OR-1896, as assessed by western blotting, flow cytometry, and qRT-PCR. Instead, the metabolites impaired IL-1β-induced ROS formation via inactivation of the MAPK p38, ERK1/2, and JNK. Our results suggest that the levosimendan metabolites OR-1896 and OR-1855 have certain anti-inflammatory properties, partly other than levosimendan. Importantly, they additionally show that the intermediate metabolite OR-1855 does, in fact, have pharmacological effects in the endothelium. This is interesting, as the metabolites are responsible for the long-term therapeutic effects of levosimendan, and heart failure is associated with vascular dysfunction and inflammation.

The effects of levosimendan in patients undergoing transcatheter aortic valve replacement- a retrospective analysis

Background: Aortic stenosis (AS) increases left ventricular afterload, leading to cardiac damage and heart failure (HF). Transcatheter aortic valve replacement (TAVR) is an effective therapy for AS. No inotropic agents including levosimendan have been evaluated in patients undergoing TAVR. Methods: A total of 285 patients underwent TAVR between 2014 and 2019; 210 were included in the matched analysis and 105 received 0.1 μg/kg body weight/min levosimendan immediately after the prosthesis had been successfully implanted. Medical history, laboratory tests, and echocardiography results were analyzed. Endpoints including 2-year all-cause mortality, stroke, or HF-related hospitalization, and a combination of the above were analyzed by Cox proportional hazard models. Results: The levosimendan group had no difference in 2-year mortality compared with the control group (hazard ratio [HR]: 0.603, 95% confidence interval [CI]: 0.197-1.844; p = 0.375). However, levosimendan reduced stroke or HF-related hospitalization (HR: 0.346; 95% CI: 0.135-0.884; p = 0.027) and the combined endpoint (HR: 0.459, 95% CI: 0.215-0.980; p = 0.044). After adjusting for multiple variants, levosimendan still reduced stroke or HF-related hospitalization (HR: 0.346, 95% CI: 0.134-0.944; p = 0.038). Conclusion: Prophylactic levosimendan administration immediately after valve implantation in patients undergoing TAVR can reduce stroke or HF-related hospitalization but does not lower all-cause mortality.

Levosimendan Administration May Provide More Benefit for Survival in Patients with Non-Ischemic Cardiomyopathy Experiencing Acute Decompensated Heart Failure

Background: Acute decompensated heart failure (ADHF) is a life-threatening condition with a high mortality rate. Levosimendan is an effective inotropic agent used to maintain cardiac output and a long-lasting effect. However, only few studies have compared the clinical outcomes, after levosimendan therapy, among etiologies of ADHF. Methods: Between July 2014 and December 2019, 184 patients received levosimendan therapy for ADHF at our hospital. A total of 143 patients had ischemic cardiomyopathy (ICM), and 41 patients had non-ICM (NICM). Data on comorbidities, echocardiographic findings, laboratory findings, use of mechanical devices, consumption of other inotropic or vasopressor agents, frequency of HF hospitalization, cardiovascular (CV) mortality, and all-cause mortality were compared between the ICM and NICM groups. Results: Patients with ICM were older with higher prevalence of diabetes mellitus when compared to patients with NICM. Patients with NICM had a poorer left ventricular ejection fraction (LVEF) and higher left ventricular end-systolic volume when compared to patients with ICM. At the 30 day follow-up period, a lower CV mortality (ICM vs. NICM: 20.9% vs. 5.1%; log-rank p = 0.033) and lower all-cause mortality (ICM vs. NICM: 28.7% vs. 9.8%; log-rank p = 0.018) was observed in the NICM patients. A significantly lower all-cause mortality was noted at 180 day (ICM vs. NICM: 39.2% vs. 22.0%; log-rank p = 0.043) and 1 year (ICM vs. NICM: 41.3% vs. 24.4%; log-rank p = 0.046) follow up in the NICM subgroup. NICM (hazard ratio (HR): 0.303, 95% confidence interval (CI): 0.108–0.845; p = 0.023) and ECMO use (HR: 2.550, 95% CI: 1.385–4.693; p = 0.003) were significant predictors of 30 day all-cause mortality. Conclusions: In our study on levosimendan use for ADHF patients, better clinical outcomes were noted in the NICM population when compared to the ICM population. In the patients with cardiogenic shock or ventilator use, significantly lower incidence of 30 day mortality presented in the NICM population when compared with the ICM population.

Update of Takotsubo cardiomyopathy: Present experience and outlook for the future

Takotsubo cardiomyopathy (TTS) has become a recognised clinical entity since the Japanese scientist Sato first described it in 1990. Despite an increasing number of confirmed cases, especially during the COVID-19 pandemic, its pathophysiology remains incompletely understood, and decision-making differs in the diagnosis and treatment. In addition, it is not evident whether a significant increase in TTS is due to better understanding among practitioners and widespread access to coronary angiography, or if it is a reflection of an actual increase in incidence. We analysed a series of international research studies from 1990 to 2021. Beyond epidemiology and clinical presentation, we evaluated and summarised fundamental knowledge about various predisposing factors, with particular attention to the iatrogenic impact of certain drugs, namely antidepressants, chemotherapy, and antiarrhythmics. Furthermore, we highlighted the main pathophysiological theories to date. In addition, based on published studies and clinical cases, we investigated the role of numerous diagnostic approaches in the differential diagnosis of TTS and identified predictors of TTS complications, such as cardiogenic shock, ventricular fibrillation, and left ventricular thrombi. Accordingly, we sought to propose a diagnostic algorithm and further treatment management of TTS under the presence of possible complications to help practitioners make more informed decisions, as the initial presentation continues to pose a challenge due to its close similarity to acute coronary syndrome with ST-elevation. In conclusion, this article examines Takotsubo cardiomyopathy from different perspectives and, along with future systematic reviews and meta-analyses, can be of particular interest to practising cardiologists and researchers in developing clinical guidelines.

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.

Considerations for Inotrope and Vasopressor Use in Critically Ill Patients With Pulmonary Arterial Hypertension

ABSTRACT

Pulmonary arterial hypertension (PAH) is a rare and progressive cardiopulmonary disease, characterized by pulmonary vasculopathy. The disease can lead to increase pulmonary arterial pressures and eventual right ventricle failure due to elevated afterload. The prevalence of PAH in patients admitted to the intensive care unit (ICU) is unknown, and pulmonary hypertension (PH) in the ICU is more commonly the result of left heart disease or hypoxic lung injury (PH due to left heart disease and PH due to lung diseases and/or hypoxia, respectively), as opposed to PAH. Management of patients with PAH in the ICU is complex as it requires a careful balance to maintain perfusion while optimizing right-sided heart function. A comprehensive understanding of the underlying physiology and underlying hemodynamics is crucial for the management of this population. In this review, we summarized the evidence for use of vasopressors and inotropes in the management of PH and extrapolated the data to patients with PAH. We strongly believe that the understanding of the hemodynamic consequences of inotropes and vasopressors, especially from data in the PH population, can lead to better management of this complex patient population.

Levosimendan in Europe and China: An Appraisal of Evidence and Context

The calcium sensitiser levosimendan (SIMDAX; Orion Pharma) has been in clinical use for the management of acute heart failure and a range of related syndromes in many countries around the world for two decades. More recently, levosimendan has become available in China. The authors have examined the profile of levosimendan in clinical trials conducted inside and outside China and grouped the findings under six headings: effects on haemodynamics, effects on natriuretic peptides, effect on symptoms of heart failure, renal effects, effect on survival, and safety profile. Their conclusions are that under each of these headings there are reasonable grounds to expect that the effects and clinical benefits established in trials and with wider clinical use in Europe and elsewhere will accrue also to Chinese patients. Therefore, the authors are confident that global experience with levosimendan provides a reliable guide to its optimal use and likely therapeutic effects in patients in China.

Levosimendan-induced venodilation is mediated by opening of potassium channels

Unique vascular responses adhere to the cardiovascular efficacy of the inodilator levosimendan. In particular, selective venodilation appears to explain its clinical benefit during pulmonary hypertension complicated by heart failure with preserved ejection fraction. Vasodilators increase vessel diameter in various parts of the vascular system to different degrees and thereby influence blood pressure, its distribution, and organ perfusion depending on their mechanisms of action. Levosimendan and its long‐lived active metabolite OR‐1896 mobilize a set of vasodilatory mechanisms, that is, the opening of the ATP‐sensitive K⁺ channels and other K⁺ channels on top of a highly selective inhibition of the phosphodiesterase III enzyme. A vessel‐specific combination of the above vasodilator mechanisms—in concert with cardiac effects and cardiovascular reflex regulations—illustrates the pharmacological profile of levosimendan in various cardiovascular disorders. While levosimendan has been known to be an inotrope, its properties as an activator of ATP‐sensitive K⁺ channels have gone largely ignored with respect to clinical applications. Here, we provide a summary of what is known about the ATP‐sensitive K⁺ channel properties in preclinical studies and now for the first time, its ATP‐sensitive K⁺ channel properties in a clinical trial.

[Levosimendan - a 20-Year Experience]

Levosimendan is a calcium sensitizer and opens adenosine triphosphate-dependent potassium channels. Since 20 years, it is approved for acute decompensated heart failure. It has been tested in many clinical trials for treatment of at-risk patients in cardiac surgery, right ventricular failure, pulmonary hypertension, weaning of extracorporeal systems, cardiogenic shock, septic shock, ARDS and others.Levosimendan has diverse positive effects next to positive inotropy. It improves ventriculoarterial coupling, increases peripheral perfusion, increases kidney glomerular filtration rate, coronary blood flow and it reduces preload and afterload as well as pulmonary capillary wedge pressure.Due to the opening of potassium channels, it also acts on mitochondria resulting in organ protection. Levosimendan acts anti-apoptotic. These positive effects were described in many small studies. Although this sounds like a promising drug for a variety of settings, results of several multicentre randomized placebo-controlled studies were frustrating. This review resumes some facts of levosimendan in different diseases.

Rationale, experimental data, and emerging clinical evidence on early and preventive use of levosimendan in patients with ventricular dysfunction

Acute ventricular dysfunction (AVD) is a complex condition with substantial morbidity and mortality, still featuring unique therapeutic challenges. Levosimendan is a calcium sensitizer and ATP-dependent potassium channel opener that was developed as an inodilating drug for the treatment of acute heart failure and cardiogenic shock. Differently from other more widely used inotropic agents, levosimendan has some exclusive characteristics, in terms of mechanisms of action, pharmacodynamic profile, and haemodynamic effects. This may have important clinical implications. In particular, in patients with AVD or in patients with pre-existing severe ventricular impairment undergoing planned myocardial stress, the administration of levosimendan before the onset of overt symptoms or before cardiovascular therapeutic procedures may have the potential to bridge the patient through the critical phase. In this review, we will focus on the rationale, the existing experimental data, and the emerging clinical experience supporting an early, even preventive use of levosimendan in severe ventricular dysfunction, beyond its recognized indications.

Potential of the Cardiovascular Drug Levosimendan in the Management of Amyotrophic Lateral Sclerosis: An Overview of a Working Hypothesis

Levosimendan is a calcium sensitizer that promotes myocyte contractility through its calcium-dependent interaction with cardiac troponin C. Administered intravenously, it has been used for nearly 2 decades to treat acute and advanced heart failure and to support the heart function in various therapy settings characterized by low cardiac output. Effects of levosimendan on noncardiac muscle suggest a possible new application in the treatment of people with amyotrophic lateral sclerosis (ALS), a neuromuscular disorder characterized by progressive weakness, and eventual paralysis. Previous attempts to improve the muscle response in ALS patients and thereby maintain respiratory function and delay progression of disability have produced some mixed results. Continuing this line of investigation, levosimendan has been shown to enhance in vitro the contractility of the diaphragm muscle fibers of non-ALS patients and to improve in vivo diaphragm neuromuscular efficiency in healthy subjects. Possible positive effects on respiratory function in people with ALS were seen in an exploratory phase 2 study, and a phase 3 clinical trial is now underway to evaluate the potential benefit of an oral form of levosimendan on both respiratory and overall functions in patients with ALS. Here, we will review the various known pharmacologic effects of levosimendan, considering their relevance to people living with ALS.

Levosimendan Efficacy and Safety: 20 years of SIMDAX in Clinical Use

Levosimendan was first approved for clinic use in 2000, when authorisation was granted by Swedish regulatory authorities for the haemodynamic stabilisation of patients with acutely decompensated chronic heart failure. In the ensuing 20 years, this distinctive inodilator, which enhances cardiac contractility through calcium sensitisation and promotes vasodilatation through the opening of adenosine triphosphate-dependent potassium channels on vascular smooth muscle cells, has been approved in more than 60 jurisdictions, including most of the countries of the European Union and Latin America. Areas of clinical application have expanded considerably and now include cardiogenic shock, takotsubo cardiomyopathy, advanced heart failure, right ventricular failure and pulmonary hypertension, cardiac surgery, critical care and emergency medicine. Levosimendan is currently in active clinical evaluation in the US. Levosimendan in IV formulation is being used as a research tool in the exploration of a wide range of cardiac and non-cardiac disease states. A levosimendan oral form is at present under evaluation in the management of amyotrophic lateral sclerosis. To mark the 20 years since the advent of levosimendan in clinical use, 51 experts from 23 European countries (Austria, Belgium, Croatia, Cyprus, Czech Republic, Estonia, Finland, France, Germany, Greece, Hungary, Italy, the Netherlands, Norway, Poland, Portugal, Russia, Slovenia, Spain, Sweden, Switzerland, UK and Ukraine) contributed to this essay, which evaluates one of the relatively few drugs to have been successfully introduced into the acute heart failure arena in recent times and charts a possible development trajectory for the next 20 years.

Levosimendan Efficacy and Safety: 20 Years of SIMDAX in Clinical Use

Levosimendan was first approved for clinical use in 2000, when authorization was granted by Swedish regulatory authorities for the hemodynamic stabilization of patients with acutely decompensated chronic heart failure (HF). In the ensuing 20 years, this distinctive inodilator, which enhances cardiac contractility through calcium sensitization and promotes vasodilatation through the opening of adenosine triphosphate-dependent potassium channels on vascular smooth muscle cells, has been approved in more than 60 jurisdictions, including most of the countries of the European Union and Latin America. Areas of clinical application have expanded considerably and now include cardiogenic shock, takotsubo cardiomyopathy, advanced HF, right ventricular failure, pulmonary hypertension, cardiac surgery, critical care, and emergency medicine. Levosimendan is currently in active clinical evaluation in the United States. Levosimendan in IV formulation is being used as a research tool in the exploration of a wide range of cardiac and noncardiac disease states. A levosimendan oral form is at present under evaluation in the management of amyotrophic lateral sclerosis. To mark the 20 years since the advent of levosimendan in clinical use, 51 experts from 23 European countries (Austria, Belgium, Croatia, Cyprus, Czech Republic, Estonia, Finland, France, Germany, Greece, Hungary, Italy, the Netherlands, Norway, Poland, Portugal, Russia, Slovenia, Spain, Sweden, Switzerland, the United Kingdom, and Ukraine) contributed to this essay, which evaluates one of the relatively few drugs to have been successfully introduced into the acute HF arena in recent times and charts a possible development trajectory for the next 20 years.

The Novel Inodilator ORM-3819 Relaxes Isolated Porcine Coronary Arteries: Role of Voltage-Gated Potassium Channel Activation

Relaxation and changes in the transmembrane potential of vascular smooth muscle induced by ORM-3819, a novel inodilating compound, were investigated in isolated porcine coronary arteries. Isometric tone was studied on arterial rings precontracted by KCl (30 mM), and resting membrane potential was investigated by a conventional microelectrode technique. ORM-3819 in the concentration range 0.38-230.6 µM evoked concentration-dependent relaxation with a maximum value of 58.1% and an effective concentration of the relaxing substance that caused 50% of maximum relaxation of 72.2 µM. The maximum hyperpolarization produced by ORM-3819 at a concentration of 120 µM (-2.6 ± 0.81 mV, N = 10) did not differ significantly from that induced by C-type natriuretic peptide (CNP), an endogenous hyperpolarizing mediator, at a concentration of 1.4 µM (-3.6 ± 0.38 mV, N = 17). The same effect elicited by the known inodilator levosimendan was less pronounced at a concentration of 3.7 µM: -1.82 ± 0.44 mV, N = 22 (P < 0.05 vs. CNP). The voltage-gated potassium channel inhibitor 4-aminopyridine, at a concentration of 5 mM, attenuated the relaxation induced by ORM-3819 at concentrations of 41.6 or 117.2 µM. These results suggest that ORM-3819 is a potent vasodilating agent able to relieve coronary artery vasospasm by causing hyperpolarization of vascular smooth muscle cells through processes involving activation of voltage-gated potassium channels.

Cardiac Inotropes Offer Protection of Renal Function in Patients with Kidney Transplantation

INTRODUCTION

Impaired cardiac function is one of the most concomitant symptoms in patients with kidney failure after long-term dialysis. In addition, the preservation of adequate perfusion pressure to the graft plays a significant role in the intraoperative management during kidney transplantation, but the use of positive inotropic drugs in kidney transplant patients has been studied less. We investigated the protective effects of renal function by means of cardiac inotropes in kidney transplant patients.

METHODS

Eighty-nine patients that received kidney transplantation between April 2014 and December 2016 at Qilu Hospital were included and randomly divided into the treatment group receiving levosimendan and a control group. All kidney recipients received ABO-compatible donors. A poor outcome was defined as one of the following: delayed graft function, graft hemorrhage, or nephrectomy.

RESULTS

The treatment group had a better composite outcome and the level of neutrophil gelatinase-associated lipocalin was also lower than in the control group.

CONCLUSION

Inotropic drugs may play a protective role in renal function in kidney transplantation.

Levosimendan and systemic vascular resistance in cardiac surgery patients: a systematic review and meta-analysis

Levosimendan is a potent non-adrenergic inodilator agent. The net effect of hemodynamic changes may result in a hyperdynamic state with low systemic vascular resistance. We conducted a systematic review and meta-analysis assessing hemodynamics in cardiac surgery patients treated with levosimendan. English-language literature was searched systematically from 2006 until October 2018, including randomized controlled trials and case-matched or retrospective studies providing at least two sequentially measured hemodynamic variables in adult patients who underwent cardiac surgery with cardiopulmonary bypass and were treated with levosimendan in comparison to alternative drugs or devices. Cardiac index significantly increased in the levosimendan group by 0.74 (0.24 to 1.23) [standardized mean difference (95% CI); p = 0.003] from baseline to postoperative day (POD) 1, and by 0.75 (0.25 to 1.25; p = 0.003) from baseline to POD 7, when corrected for the standardized mean difference at baseline by a multivariate mixed effects meta-analysis model. With this correction for baseline differences, other hemodynamic variables including systemic vascular resistance did not significantly differ until POD 1 [−0.17 (−0.64 to 0.30), p = 0.48] and POD 7 [−0.13 (−0.61 to 0.34), p = 0.58] between the levosimendan and the comparator group. Levosimendan increases cardiac index in patients undergoing cardiac surgery. Although levosimendan has inodilator properties, this meta-analysis finds no clinical evidence that levosimendan produces vasopressor-resistant vasoplegic syndrome.

Levosimendan in the light of the results of the recent randomized controlled trials: an expert opinion paper

Despite interesting and unique pharmacological properties, levosimendan has not proven a clear superiority to placebo in the patient populations that have been enrolled in the various recent multicenter randomized controlled trials. However, the pharmacodynamic effects of levosimendan are still considered potentially very useful in a number of specific situations.Patients with decompensated heart failure requiring inotropic support and receiving beta-blockers represent the most widely accepted indication. Repeated infusions of levosimendan are increasingly used to facilitate weaning from dobutamine and avoid prolonged hospitalizations in patients with end-stage heart failure, awaiting heart transplantation or left ventricular assist device implantation. New trials are under way to confirm or refute the potential usefulness of levosimendan to facilitate weaning from veno-arterial ECMO, to treat cardiogenic shock due to left or right ventricular failure because the current evidence is mostly retrospective and requires confirmation with better-designed studies. Takotsubo syndrome may represent an ideal target for this non-adrenergic inotrope, but this statement also relies on expert opinion. There is no benefit from levosimendan in patients with septic shock. The two large trials evaluating the prophylactic administration of levosimendan (pharmacological preconditioning) in cardiac surgical patients with poor left ventricular ejection fraction could not show a significant reduction in their composite endpoints reflecting low cardiac output syndrome with respect to placebo. However, the subgroup of those who underwent isolated CABG appeared to have a reduction in mortality. A new study will be required to confirm this exploratory finding.Levosimendan remains a potentially useful inodilator agent in a number of specific situations due to its unique pharmacological properties. More studies are needed to provide a higher level of proof regarding these indications.

Multiorgan Drug Action of Levosimendan in Critical Illnesses

Cardiotonic drugs mainly include digitalis, catecholamines, phosphodiesterase inhibitors, and calcium sensitizers, which have been successively discovered and applied in clinical practice. However, there are only a few new drugs available in this field, and the selection is very limited. Digitalis, catecholamines, and phosphodiesterase inhibitors increase myocardial contractility by increasing intracellular concentrations of cyclic adenosine monophosphate (cAMP) and Ca²⁺, and this increase in intracellular calcium ion concentration enhances myocardial oxygen consumption and causes arrhythmia. For these reasons, the research focus on positive inotropic agents has shifted from calcium mobilization to calcium sensitization. Intracellular calcium sensitizers are more effective and safer drugs because they do not increase the intracellular concentration of calcium ions. However, only three calcium sensitizers have been fully developed and used in the past three decades. One of these drugs, levosimendan, has multiple molecular targets and exerts its pharmacological effects by not only increasing myocardial contractility, but also enhancing respiratory muscle function and liver and kidney protection, and it is useful for patients with severe sepsis and septic shock. Recently, more than 60 randomized controlled clinical trials of levosimendan have been reported; however, these clinical trials have occasionally shown different findings. This article reviews the research progress of levosimendan in critical illnesses in recent years.

Beneficial effects of levosimendan on survival in patients undergoing extracorporeal membrane oxygenation after cardiovascular surgery

BACKGROUND

The impact of levosimendan treatment on clinical outcome in patients undergoing extracorporeal membrane oxygenation (ECMO) support after cardiovascular surgery is unknown. We hypothesized that the beneficial effects of levosimendan might improve survival when adequate end-organ perfusion is ensured by concomitant ECMO therapy. We therefore studied the impact of levosimendan treatment on survival and failure of ECMO weaning in patients after cardiovascular surgery.

METHODS

We enrolled a total of 240 patients undergoing veno-arterial ECMO therapy after cardiovascular surgery at a university-affiliated tertiary care centre into our observational single-centre registry.

RESULTS

During a median follow-up period of 37 months (interquartile range 19-67 months), 65% of patients died. Seventy-five per cent of patients received levosimendan treatment within the first 24 h after initiation of ECMO therapy. Cox regression analysis showed an association between levosimendan treatment and successful ECMO weaning [adjusted hazard ratio (HR) 0.41; 95% confience interval (CI) 0.22-0.80; P=0.008], 30 day mortality (adjusted HR 0.52; 95% CI 0.30-0.89; P=0.016), and long-term mortality (adjusted HR 0.64; 95% CI 0.42-0.98; P=0.04).

CONCLUSIONS

These data suggest an association between levosimendan treatment and improved short- and long-term survival in patients undergoing ECMO support after cardiovascular surgery.

Levosimendan in pulmonary hypertension and right heart failure

Pulmonary hypertension is a multifactorial disease with a high morbidity and mortality. Right ventricular function is the most important predictor of morbidity and mortality in patients suffering from pulmonary hypertension, but currently there are no approved treatments directly supporting the failing right ventricle. Levosimendan is a calcium sensitizing agent with inotropic, pulmonary vasodilatory, and cardioprotective properties. Given its pharmacodynamic profile, levosimendan could be a potential novel agent for the treatment of right ventricular failure caused by pulmonary hypertension. The aim of this review is to provide an overview of the current knowledge on the effects of levosimendan in pulmonary hypertension and right heart failure.

Modification of levosimendan-induced suppression of atrial natriuretic peptide secretion in hypertrophied rat atria

This study aimed to determine the effects of levosimendan, a calcium sensitizer, on atrial contractility and atrial natriuretic peptide (ANP) secretion and its modification in hypertrophied atria. Isolated perfused beating rat atria were used from control and isoproterenol-treated rats. Levosimendan and its metabolite OR-1896 caused a positive inotropic effect and suppressed ANP secretion in rat atria. Similar to levosimendan, the selective phosphodiesterase 3 (PDE3) or PDE4 inhibitor also suppressed ANP secretion. Suppression of ANP secretion by 1 µM levosimendan was abolished by PDE3 inhibitor, but reversed by PDE4 inhibitor. Levosimendan-induced suppression of ANP secretion was potentiated by K_ATP channel blocker, but blocked by K_ATP channel opener. Levosimendan alone did not significantly change cyclic adenosine monophosphate (cAMP) efflux in the perfusate; however, levosimendan combined with PDE4 inhibitor markedly increased this efflux. The stimulation of ANP secretion induced by levosimendan combined with PDE4 inhibitor was blocked by the protein kinase A (PKA) inhibitor. In isoproterenol-treated atria, levosimendan augmented the positive inotropic effect and ANP secretion in response to an increased extracellular calcium concentration ([Ca⁺]_o). These results suggests that levosimendan suppresses ANP secretion by both inhibiting PDE3 and opening K_ATP channels and that levosimendan combined with PDE4 inhibitor stimulates ANP secretion by activating the cAMP-PKA pathway. Modification of the effects of levosimendan on [Ca⁺]_o-induced positive inotropic effects and ANP secretion in isoproterenol-treated rat atria might be related to a disturbance in calcium metabolism.

Levosimendan for Pediatric Anomalous Left Coronary Artery From the Pulmonary Artery Undergoing Repair: A Single-Center Experience

Objectives: Our aim was to retrospectively evaluate the benefit of levosimendan in certain complicated congenital heart procedures such as the pediatric anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) with moderate or severe cardiac dysfunction and its repair. Study Design: We enrolled 40 pediatric patients with ALCAPA and moderate or severe left ventricular dysfunction. Patients who had a preoperative left ventricular ejection fraction (LVEF) of 50% or less and had undergone the surgical correction of their coronary artery through cardiopulmonary bypass met the criteria of our study. Twenty patients were given 0.1-0.2 μg/kg/min levosimendan at the induction of anesthesia, which lasted for 24 h. The remaining 20 patients were not given levosimendan. Results: The mean preoperative LVEF in the levosimendan group was significantly lower than that in the non-levosimendan group (22.5 ± 10.7% vs. 31.8 ± 8.1%, p = 0.004). On postoperative day 7, the LVEF in the levosimendan group was still significantly lower (27.1 ± 8.9% vs. 37.5 ± 11.0%, p = 0.002). There was no significant difference in ΔLVEF detected on day 7 [median 30.8%, interquartile range (IQR) -4.4 to 63.5% vs. median 15.1%, IQR -3.5 to 40.0%, p = 0.560] or at follow-up of about 180 days (median 123.5%, IQR 56.1-222.6% vs. median 80.0%, IQR 36.4-131.3%, p = 0.064). There was no significant difference between the two groups in postoperative vasoactive-inotropic score (VIS) at any of the time points of 1, 6, 12, 24, and 48 h (p = 0.093). Three patients had to be supported by extracorporeal membrane oxygenation when difficulty appeared in weaning off cardiopulmonary bypass because of low cardiac output in the non-levosimendan group, but no patient needed extracorporeal membrane oxygenation after levosimendan infusion (p = 0.231). The length of intensive care unit stay (median 10.5 days, IQR 7.3-39.3 days vs. median 4.0 days, IQR 2.0-10.0 days, p = 0.002) and duration of mechanical ventilation (median 146.0 h, IQR 76.5-888.0 h vs. median 27.0 h, IQR 11.0-75.0 h, p = 0.002) were revealed to be longer in the levosimendan group. Peritoneal dialysis occurred in eight patients (40%) in the levosimendan group and two patients (10%) in the non-levosimendan group (p = 0.028). No significant difference was revealed in all-cause mortality within 180 days, which occurred in two patients (10%) in the levosimendan group and one (5%) in the non-levosimendan group (p = 1.00). Conclusion: Levosimendan's unique pharmacological properties have strong potential for cardiac function recovery among pediatric patients with ALCAPA with impaired left ventricular function who have undergone surgical repair.However, any improvement from levosimendan on postoperative outcomes or mortality was not substantiated by this study and must be investigated further.

Levosimendan exerts anticonvulsant properties against PTZ-induced seizures in mice through activation of nNOS/NO pathway: Role for KATP channel

AIMS

Although approving new anticonvulsants was a major breakthrough in the field of epilepsy control, so far we have met limited success in almost one third of patients suffering from epilepsy and a definite and reliable method is yet to be found. Levosimendan demonstrated neuroprotective effects and reduced mortality in conditions in which seizure can be an etiology of death; however, the underlying neuroprotective mechanisms of levosimendan still eludes us. In the light of evidence suggesting levosimendan can be a K_ATP channel opener and nitrergic pathway activator, levosimendan may exert antiseizure effects through K_ATP channels and nitrergic pathway.

MAIN METHODS

In this study, the effects of levosimendan on seizure susceptibility was studied by PTZ-induced seizures model in mice.

KEY FINDINGS

Administration of a single effective dose of levosimendan significantly increased seizures threshold and the nitrite level in the hippocampus and temporal cortex. Pretreatment with noneffective doses of glibenclamide (a K_ATP channel blocker) and L-NAME (a non-selective NOS inhibitor) neutralize the anticonvulsant and nitrite elevating effects of levosimendan. While 7-NI (a neural NOS inhibitor) blocked the anticonvulsant effect of levosimendan, Aminoguanidine (an inducible NOS inhibitor) failed to affect the anticonvulsant effects of levosimendan. Cromakalim (a K_ATP channel opener) or l-arginine (an NO precursor) augmented the anticonvulsant effects of a subeffective dose of levosimendan. Moreover, co-administration of noneffective doses of Glibenclamide and L-NAME demonstrated a synergistic effect in blocking the anticonvulsant effects of levosimendan.

SIGNIFICANCE

Levosimendan has anticonvulsant effects possibly via K_ATP/nNOS/NO pathway activation in the hippocampus and temporal cortex.

Advanced heart failure: an appraisal of the potential of levosimendan in this end-stage scenario and some related ethical considerations

INTRODUCTION

The later stages of heart failure are characterized by a steady decline in quality of life. Clinical priorities should be to maintain functional capacity and quality of life. In the absence of sufficient organs for transplantation, options include left ventricular assist devices and inotropic support. Areas covered: We examined data published in the last two decades on the use of inotropes and inodilators in advanced heart failure. Expert commentary: In the literature, use of conventional inotropes, including adrenergic agonists and phosphodiesterase inhibitors, appears to be suboptimal for achieving the clinical priorities of late-stage heart failure. Evidence suggests instead that the calcium-sensitizing inodilator levosimendan, administered intermittently, delivers improvements in functional capacity and quality of life and does so with no adverse impact on life expectancy. At a terminal or near-terminal stage of heart failure, the therapeutic philosophy should shift towards meeting patients' existential priorities rather than traditional heart failure-centric targets.

Comparison of levosimendan and nitroglycerine in patients undergoing coronary artery bypass graft surgery

Background:

Levosimendan a calcium ion sensitizer improves both systolic and diastolic functions. This novel lusitropic drug has predictable antiischemic properties which are mediated via the opening of mitochondrial adenosine triphosphate-sensitive potassium channels. This action of levosimendan is beneficial in cardiac surgical patients as it improves myocardial contractility, decreases systemic vascular resistance (SVR), and increases cardiac index (CI) and is thought to be cardioprotective. We decided to study whether levosimendan has any impact on the outcomes such as the duration of ventilation, the length of Intensive Care Unit (ICU) stay, and the hospital stay when compared with the nitroglycerine (NTG), which is the current standard of care at our center.

Materials and Methods:

Forty-seven patients undergoing elective coronary artery bypass surgery were randomly assigned to two groups receiving either levosimendan or NTG. The medications were started before starting surgery and continued until 24 h in the postoperative period. Baseline hemodynamic parameters were evaluated before beginning of the operation and then postoperatively at 3 different time intervals. N-terminal fragment of pro-brain natriuretic peptide (NT-proBNP) levels were also measured in both groups.

Results:

In comparison to the NTG group, the duration of ventilation and length of ICU stay were significantly less in levosimendan group (P < 0.05, P = 0.02). NT-proBNP level analysis showed a slow rising pattern in both groups and a statistically significant rise in the levels was observed in NTG group (P = 0.03, P = 0.02) in postoperative period when compared to levosimendan group of patients.

Conclusion:

Levosimendan treatment in patients undergoing surgical revascularization resulted in improved CI, decreased SVR and lower heart rate. And, thereby the duration of ventilation and length of ICU stay were significantly less in this group of patients when compared with NTG group.

[Use of levosimendan in children]

Levosimendan is a calcium-sensitizing drug with positive inotropic properties. As an inodilator, this molecule also has a vasodilation effect. While its efficacy has been demonstrated in the adult in the context of cardiac surgery, its pediatric use is still not widespread. Many studies have shown its safety of use in children, including in the newborn. Across the world, a growing number of teams use levosimendan to treat both acute and chronic heart failure. Through a review of the literature, we describe its pharmacodynamic effects, its current applications, and its perspectives of use in children.

Levosimendan. A promising future drug for refractory cardiac failure in children?

Intravenous positive inotropic agents play an important role in treating acute decompensation of patients with heart failure due to left ventricular systolic dysfunction. Levosimendan is a new positive inotropic agent having ATP-dependent potassium-channel opening, and calcium-sensitizing effects, which increases cardiac contractility and performance along with vasodilatatory action without increasing myocardial oxygen demand. We report a case of a 12-year-old girl with viral myocarditis, dilated cardiomyopathy, biventricular failure with severe left ventricular dysfunction, refractory to standard management, and who was successfully improved with levosimendan.

Inhibition of phosphodiesterase-3 by levosimendan is sufficient to account for its inotropic effect in failing human heart

BACKGROUND AND PURPOSE

Levosimendan is known as a calcium sensitizer, although it is also known to inhibit PDE3. We aimed to isolate each component and estimate their contribution to the increased cardiac contractility induced by levosimendan.

EXPERIMENTAL APPROACH

Contractile force was measured in electrically stimulated ventricular strips from explanted failing human hearts and left ventricular strips from normal male Wistar rats. PDE activity was measured in a two-step PDE activity assay on failing human ventricle.

KEY RESULTS

Levosimendan exerted a positive inotropic effect (PIE) reaching maximum at 10(-5)  M in ventricular strips from failing human hearts. In the presence of the selective PDE3 inhibitor cilostamide, the PIE of levosimendan was abolished. During treatment with a PDE4 inhibitor and a supra-threshold concentration of isoprenaline, levosimendan generated an amplified inotropic response. This effect was reversed by β-adrenoceptor blockade and undetectable in strips pretreated with cilostamide. Levosimendan (10(-6)  M) increased the potency of β-adrenoceptor agonists by 0.5 log units in failing human myocardium, but not in the presence of cilostamide. Every inotropic response to levosimendan was associated with a lusitropic response. Levosimendan did not affect the concentration-response curve to calcium in rat ventricular strips, in contrast to the effects of a known calcium sensitizer, EMD57033 [5-(1-(3,4-dimethoxybenzoyl)-1,2,3,4-tetrahydroquinolin-6-yl)-6-methyl-3,6-dihydro-2H-1,3,4-thiadiazin-2-one]. PDE activity assays confirmed that levosimendan inhibited PDE3 as effectively as cilostamide.

CONCLUSIONS AND IMPLICATIONS

Our results indicate that the PDE3-inhibitory property of levosimendan was enough to account for its inotropic effect, leaving a minor, if any, effect to a calcium-sensitizing component.

Levosimendan suppresses oxidative injury, apoptotic signaling and mitochondrial degeneration in streptozotocin-induced diabetic cardiomyopathy

Diabetic cardiomyopathy plays a major role in morbidity and mortality among cardiovascular disorder-related complications. This study was designed to explore long-term benefits of Levosimendan (LEVO) along with Ramipril and Insulin. Diabetic cardiomyopathy was induced using streptozotocin (STZ) at the dose of 25 mg/kg/body weight/day for three consecutive days in Wistar rats. Rats were randomly divided into 10 groups and treatments were started after 2 weeks of STZ administration. A gradual but severe hyperglycemia ((§§§)p < 0.001) was observed in all STZ-treated groups except those received insulin (2  U/day). LEVO alone and in combination with Ramipril and Insulin normalized (**p < 0.01) mean arterial pressure and heart rate, restored catalase, superoxide dismutase, malondialdehyde, glutathione level and also attenuated (***p < 0.001) the raised serum levels of creatine kinase-heart type, lactate dehydrogenase, tumor necrosis factor-alpha, C-reactive protein, and caspase-3 level in heart tissue altered after STZ treatment. Myofibril degeneration, mitochondrial fibrosis and vacuolization occurred after STZ treatment, were also reversed by LEVO in combination with Ramipril and Insulin. The combination of LEVO with Ramipril and Insulin improved hemodynamic functions, maintained cardiac enzymes and ameliorated myofibril damage in diabetic cardiomyopathy.

Shock management in acute myocardial infarction

AIMS

This manuscript outlines the treatment of cardiogenic shock (CS) complicating acute myocardial infarction (AMI), focusing on new therapeutic strategies from the interventional cardiologist's perspective.

METHODS AND RESULTS

CS is a life-threatening complication of AMI occurring in 10% of AMI patients. It can be defined as a state of critical tissue and end-organ hypoperfusion due to reduced cardiac contractility. Early revascularisation is the most important therapeutic measure. Its widespread use has caused a decline in the incidence of CS. However, despite optimal treatment, the mortality rate of CS is still approaches 50%. It is now understood that CS not only involves the heart but the whole circulatory system. In order to increase the survival rates of CS patients, the right decisions have to be taken regarding the optimal revascularisation strategy, treatment with inotropes and vasopressors, mechanical left ventricular support, management of multiorgan dysfunction syndrome, additional intensive care treatment, triage among alternative hospital care levels, and allocation of clinical resources.

CONCLUSIONS

CS mortality remains unacceptably high. In the light of very limited evidence regarding most treatment modalities, there is a clear need for adequately designed studies in order to answer the numerous unsettled issues.

Inotropes and inodilators for acute heart failure: sarcomere active drugs in focus

Acute heart failure (AHF) emerges as a major and growing epidemiological concern with high morbidity and mortality rates. Current therapies in patients with acute heart failure rely on different strategies. Patients with hypotension, hypoperfusion, or shock require inotropic support, whereas diuretics and vasodilators are recommended in patients with systemic or pulmonary congestion. Traditionally inotropic agents, referred to as Ca²⁺ mobilizers load the cardiomyocyte with Ca²⁺ and thereby increase oxygen consumption and risk for arrhythmias. These limitations of traditional inotropes may be avoided by sarcomere targeted agents. Direct activation of the cardiac sarcomere may be achieved by either sensitizing the cardiac myofilaments to Ca²⁺ or activating directly the cardiac myosin. In this review, we focus on sarcomere targeted inotropic agents, emphasizing their mechanisms of action and overview the most relevant clinical considerations.