Levosimendan does not provide mortality benefit over dobutamine in adult patients with septic shock: A meta-analysis of randomized controlled trials

Effect of levosimendan on ventricular remodelling in patients with left ventricular systolic dysfunction: a meta-analysis

Heart failure is the final stage of several cardiovascular diseases, and the key to effectively treating heart failure is to reverse or delay ventricular remodelling. Levosimendan is a novel inotropic and vasodilator agent used in heart failure, whereas the impact of levosimendan on ventricular remodelling is still unclear. This study aims to investigate the impact of levosimendan on ventricular remodelling in patients with left ventricular systolic dysfunction. Electronic databases were searched to identify eligible studies. A total of 66 randomized controlled trials involving 7968 patients were included. Meta-analysis results showed that levosimendan increased left ventricular ejection fraction [mean difference (MD) = 3.62, 95% confidence interval (CI) (2.88, 4.35), P < 0.00001] and stroke volume [MD = 6.59, 95% CI (3.22, 9.96), P = 0.0001] and significantly reduced left ventricular end-systolic volume [standard mean difference (SMD) = -0.52, 95% CI (-0.67, -0.37), P < 0.00001], left ventricular end-diastolic volume index [SMD = -1.24, 95% CI (-1.61, -0.86), P < 0.00001], and left ventricular end-systolic volume index [SMD = -1.06, 95% CI (-1.43, -0.70), P < 0.00001]. In terms of biomarkers, levosimendan significantly reduced the level of brain natriuretic peptide [SMD = -1.08, 95% CI (-1.60, -0.56), P < 0.0001], N-terminal pro-brain natriuretic peptide [SMD = -0.99, 95% CI (-1.41, -0.56), P < 0.00001], and interleukin-6 [SMD = -0.61, 95% CI (-0.86, -0.35), P < 0.00001]. Meanwhile, levosimendan may increase the incidence of hypotension [risk ratio (RR) = 1.24, 95% CI (1.12, 1.39), P < 0.0001], hypokalaemia [RR = 1.57, 95% CI (1.08, 2.28), P = 0.02], headache [RR = 1.89, 95% CI (1.50, 2.39), P < 0.00001], atrial fibrillation [RR = 1.31, 95% CI (1.12, 1.52), P = 0.0005], and premature ventricular complexes [RR = 1.86, 95% CI (1.27, 2.72), P = 0.001]. In addition, levosimendan reduced all-cause mortality [RR = 0.83, 95% CI (0.74, 0.94), P = 0.002]. In conclusion, our study found that levosimendan might reverse ventricular remodelling when applied in patients with left ventricular systolic dysfunction, especially in patients undergoing cardiac surgery, decompensated heart failure, and septic shock.

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.

Challenges in Septic Shock: From New Hemodynamics to Blood Purification Therapies

Sepsis and septic shock are associated with high mortality, with diagnosis and treatment remaining a challenge for clinicians. Their management classically encompasses hemodynamic resuscitation, antibiotic treatment, life support, and focus control; however, there are aspects that have changed. This narrative review highlights current and avant-garde methods of handling patients experiencing septic shock based on the experience of its authors and the best available evidence in a context of uncertainty. Following the first recommendation of the Surviving Sepsis Campaign guidelines, it is recommended that specific sepsis care performance improvement programs are implemented in hospitals, i.e., "Sepsis Code" programs, designed ad hoc, to achieve this goal. Regarding hemodynamics, the importance of perfusion and hemodynamic coherence stand out, which allow for the recognition of different phenotypes, determination of the ideal time for commencing vasopressor treatment, and the appropriate fluid therapy dosage. At present, this is not only important for the initial timing, but also for de-resuscitation, which involves the early weaning of support therapies, directed elimination of fluids, and fluid tolerance concept. Finally, regarding blood purification therapies, those aimed at eliminating endotoxins and cytokines are attractive in the early management of patients in septic shock.

Hemodynamic management of septic shock: beyond the Surviving Sepsis Campaign guidelines

Although the Surviving Sepsis Campaign guidelines provide standardized and generalized guidance, they are less individualized. This review focuses on recent updates in the hemodynamic management of septic shock. Monitoring and intervention for septic shock should be personalized according to the phase of shock. In the salvage phase, fluid resuscitation and vasopressors should be given to provide life-saving tissue perfusion. During the optimization phase, tissue perfusion should be optimized. In the stabilization and de-escalation phases, minimal fluid infusion and safe fluid removal should be performed, respectively, while preserving organ perfusion. There is controversy surrounding the use of restrictive versus liberal fluid strategies after initial resuscitation. Fluid administration after initial resuscitation should depend upon the patient's fluid responsiveness and requires individualized management. A number of dynamic tests have been proposed to monitor fluid responsiveness, which can help clinicians decide whether to give fluid or not. The optimal timing for the initiation of vasopressor agents is unknown. Recent data suggest that early vasopressor initiation should be considered. Inotropes can be considered in patients with decreased cardiac contractility associated with impaired tissue perfusion despite adequate volume status and arterial blood pressure. Venoarterial extracorporeal membrane oxygenation should be considered for refractory septic shock with severe cardiac systolic dysfunction.

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.

Ventriculo-arterial (un)coupling in septic shock: Impact of current and upcoming hemodynamic drugs

Sepsis is an archetype of distributive shock and combines different levels of alterations in preload, afterload, and often cardiac contractility. The use of hemodynamic drugs has evolved over the past few years, along with the invasive and non-invasive tools used to measure these components in real time. However, none of them is impeccable, which is why the mortality of septic shock remains too high. The concept of ventriculo-arterial coupling (VAC) allows for the integration of these three fundamental macroscopic hemodynamic components. In this mini review, we discuss the knowledge, tools, and limitations of VAC measurement, along with the evidence supporting ventriculo-arterial uncoupling in septic shock. Finally, the impact of recommended hemodynamic drugs and molecules on VAC is detailed.

Infection as an under-recognized precipitant of acute heart failure: prognostic and therapeutic implications

As the prevalence of heart failure (HF) continues to rise, prompt diagnosis and management of various medical conditions, which may lead to HF exacerbation and result in poor patient outcomes, are of paramount importance. Infection has been identified as a common, though under-recognized, precipitating factor of acute heart failure (AHF), which can cause rapid development or deterioration of HF signs and symptoms. Available evidence indicates that infection-related hospitalizations of patients with AHF are associated with higher mortality, protracted length of stay, and increased readmission rates. Understanding the intricate interaction of both clinical entities may provide further therapeutic strategies to prevent the occurrence of cardiac complications and improve prognosis of patients with AHF triggered by infection. The purpose of this review is to investigate the incidence of infection as a causative factor in AHF, explore its prognostic implications, elucidate the underlying pathophysiological mechanisms, and highlight the basic principles of the initial diagnostic and therapeutic interventions in the emergency department.

Septic cardiomyopathy: A narrative review

Sepsis is a systemic inflammatory response syndrome of suspected or documented infectious origin, whose outcome is multiorgan failure. Sepsis-induced myocardial dysfunction (SIMD), present in more than 50% of septic patients, is characterized by (i) left ventricular (LV) dilatation with normal or low filling pressure, (ii) right and/or LV (systolic and/or diastolic) dysfunction and (iii) reversibility. Since the first definition proposed by Parker et al. in 1984, attempts have been made to define SIMD. Many parameters are used to assess cardiac function in septic patients, sometimes making it more difficult to measure due to the intrinsic hemodynamical changes in this condition. Nevertheless, with advanced echocardiographic techniques, such as speckle tracking analysis, it is possible to diagnose and assess systolic and diastolic dysfunction, even in the earliest stages of sepsis. Cardiac magnetic resonance imaging brings new insights into the reversibility of this condition. Many uncertainties still remain regarding the mechanisms, characteristics, treatment and even prognosis of this condition. There are also inconsistent conclusions from studies, therefore this review attempts to summarize our current knowledge of SIMD.

Levosimendan: mechanistic insight and its diverse future aspects in cardiac care

Inotropic agents are generally recommended to use in patients with acute decompensated heart failure (HF) with reduced ejection fraction (HFrEF) concurrent to end-organ dysfunction. However, due to certain pharmacological limitations like developing life threatening arrhythmia and tolerance, cannot be employed as much as needed. Meanwhile, Calcium ion (Ca²⁺) sensitisers exhibits their inotropic action by increasing the sensitivity of the cardiomyocyte to intracellular Ca²⁺ ion and have been reported as emerging therapeutic alternative in HF cases. Levosimendan (LEVO) is an inodilator and with its unique pharmacology justifying its use in a wide range of cardiac alterations in HF particularly in undergoing cardiac surgery. It is also reported to be better than classical inotropes in maintaining cardiac mechanical efficacy and reducing congestion in acute HF with hypotension. This review paper was designed to compile various evidence about basic pharmacology and potential clinical aspects of LEVO in cardiac surgery and other HF associated alterations. This will benefit directly to the researcher in initiating research and to fill the gaps in the area of thrust.

Early administration of dobutamine in the treatment of septic shock patients with tumor-a retrospective comparative cohort study

Background

Studies have found that dobutamine may be beneficial to protect organs function in patients with septic shock, but there is still a lack of relevant research in septic shock patients with tumor. The study sought to explore the role of the early administration of dobutamine in the treatment of septic shock patients with tumors.

Methods

We retrospectively collected the data of tumor patients who developed septic shock at Sun Yat-sen University Cancer Center between June 2008 and November 2021. All the patients were divided into the following 3 groups: (I) the early administration group (<3 days, n=15); (II) the late administration group (≥3 days, n=22); and (III) the non-administration group (n=85). The primary observation indicator was 28-day mortality, and the secondary observation indicators included the shock reversal rate, the length of stay in the intensive care unit (ICU) and the duration of mechanical ventilation. There was no statistical difference in the basic data of the three groups.

Results

The early administration group had a significant decrease in 28-day mortality compared to the late and non-administration groups (log-rank P=0.018). The comparison between the groups showed that the 28-day mortality of the early administration group was significantly lower than that of the non-administration group [20.0% vs. 58.8%, P=0.013, hazard ratios (HRs) =0.248, 95% confidence intervals (CIs): 0.077-0.796]. There was no statistically significant difference in 28-day mortality between the late administration group and the non-administration group (63.6% vs. 58.8%, P=0.682, HR =0.983, 95% CI: 0.543-1.778). Additionally, the early administration group had a significantly increased shock reversal rate (P=0.014), shortened length of stay in the ICU (P<0.001), and reduced duration of mechanical ventilation (P=0.049).

Conclusions

Early use of dobutamine may be beneficial to reduce the in-hospital mortality of septic shock patients with tumor, but the sample size of this study was small, which still needs to be confirmed by a multi-center randomized controlled clinical study.

Die neue internationale Sepsis-Leitlinie der Surviving Sepsis Campaign 2021

The new Surviving Sepsis Campaign (SSC) guideline was substantially revised in 2021. These updated recommendations are intended to guide intensivists in providing adequate care to adult patients with sepsis or septic shock. In particular, the current SSC guideline emphasizes early recognition and stringent management in the first hours after the onset of sepsis. In particular, the implementation of acute interventions should help to improve the chances of survival of sepsis patients.This article summarizes the most important recommendations for acute therapy and presents them as a comparative overview to the previous SSC guideline and the German S3 guideline. This should allow the reader to adopt the knowledge from the new guideline into clinical practice as quickly as possible in order to improve the quality of treatment of patients with sepsis or septic shock.

The Use of Levosimendan for the Treatment of Heart Failure and its Potential Organoprotective Effects

The review article is aimed at providing a recent update on the use of levosimendan, an inotropic drug in current use for the treatment of heart failure. The review discusses its mechanisms of action, main hemodynamic effects, clinical trials and obtained evidences that have formed the basis of the current guidelines on its use, as well as the latest clinical and experimental trials evaluating its organ-protective effects. Conclusion: levosimendan has a promising potential for treating heart failure, prescribed even in low doses, and may be regarded as a drug with cerebroprotective and possible nephroprotective effects, requiring further large randomized clinical trials.

Pathophysiology, mechanisms, and managements of tissue hypoxia

Oxygen is needed to generate aerobic adenosine triphosphate and energy that is required to support vital cellular functions. Oxygen delivery (DO₂) to the tissues is determined by convective and diffusive processes. The ability of the body to adjust oxygen extraction (ERO₂) in response to changes in DO₂ is crucial to maintain constant tissue oxygen consumption (VO₂). The capability to increase ERO₂ is the result of the regulation of the circulation and the effects of the simultaneous activation of both central and local factors. The endothelium plays a crucial role in matching tissue oxygen supply to demand in situations of acute drop in tissue oxygenation. Tissue oxygenation is adequate when tissue oxygen demand is met. When DO₂ is severely compromised, a critical DO₂ value is reached below which VO₂ falls and becomes dependent on DO₂, resulting in tissue hypoxia. The different mechanisms of tissue hypoxia are circulatory, anaemic, and hypoxic, characterised by a diminished DO₂ but preserved capacity of increasing ERO₂. Cytopathic hypoxia is another mechanism of tissue hypoxia that is due to impairment in mitochondrial respiration that can be observed in septic conditions with normal overall DO₂. Sepsis induces microcirculatory alterations with decreased functional capillary density, increased number of stopped-flow capillaries, and marked heterogeneity between the areas with large intercapillary distance, resulting in impairment of the tissue to extract oxygen and to satisfy the increased tissue oxygen demand, leading to the development of tissue hypoxia. Different therapeutic approaches exist to increase DO₂ and improve microcirculation, such as fluid therapy, transfusion, vasopressors, inotropes, and vasodilators. However, the effects of these agents on microcirculation are quite variable.

[Resuscitation strategy for patients with sepsis and septic shock]

Fluid and vasopressor resuscitation is, along with antimicrobial therapy and control of the focus of infection, a basic issue of the treatment of sepsis and septic shock. There is currently no accepted protocol that we can follow for the resuscitation of these patients and the Surviving Sepsis Campaign proposes controversial measures and without sufficient evidence support to establish firm recommendations. We propose a resuscitation strategy adapted to the situation of each patient: in the patient in whom community sepsis is suspected, we consider that the early administration of 30mL/kg of crystalloids is effective and safe; in the patient with nosocomial sepsis, we must carry out a more in-depth evaluation before initiating aggressive resuscitation. In patients who do not respond to initial resuscitation, it is necessary to increase monitoring level and, depending on the hemodynamic profile, administer more fluids, a second vasopressor or inotropes.

Current practice and evolving concepts in septic shock resuscitation

Clinical and pathophysiological understanding of septic shock has progressed exponentially in the previous decades, translating into a steady decrease in septic shock-related morbidity and mortality. Even though large randomized, controlled trials have addressed fundamental aspects of septic shock resuscitation, many questions still exist. In this review, we will describe the current standards of septic shock resuscitation, but the emphasis will be placed on evolving concepts in different domains such as clinical resuscitation targets, adequate use of fluids and vasoactive drugs, refractory shock, and the use of extracorporeal therapies. Multiple research opportunities remain open, and collaborative endeavors should be performed to fill in these gaps.

Levosimendan versus dobutamine for sepsis-induced cardiac dysfunction: a systematic review and meta-analysis

Levosimendan and dobutamine are extensively used to treat sepsis-associated cardiovascular failure in ICU. Nevertheless, the role and mechanism of levosimendan in patients with sepsis-induced cardiomyopathy remains unclear. Moreover, previous studies on whether levosimendan is superior to dobutamine are still controversial. More importantly, these studies did not take changes (before-after comparison to the baseline) in quantitative parameters such as ejection fraction into account with the baseline level. Here, we aimed to determine the pros and cons of the two medicines by assessing the changes in cardiac function and blood lactate, mortality, with the standardized mean difference used as a summary statistic. Relevant studies were obtained by a thorough and disciplined literature search in several notable academic databases, including Google Scholar, PubMed, Cochrane Library and Embase until November 2020. Outcomes included changes in cardiac function, lactic acid, mortality and length of hospital stay. A total of 6 randomized controlled trials were included in this study, including 192 patients. Compared with dobutamine, patients treated with levosimendan had a greater improvement of cardiac index (ΔCI) (random effects, SMD = 0.90 [0.20,1.60]; I2 = 76%, P < 0.01) and left ventricular stroke work index (ΔLVSWI) (random effects, SMD = 1.56 [0.90,2.21]; I2 = 65%, P = 0.04), a significant decrease of blood lactate (Δblood lactate) (random effects, MD =  - 0.79 [- 1.33, - 0.25]; I2 = 68%, P < 0.01) at 24-h after drug intervention, respectively. There was no significant difference between levosimendan and dobutamine on all-cause mortality in ICU (fixed effect, OR = 0.72 [0.39,1.33]; I2 = 0%, P = 0.99). We combine effect sizes related to different measurement parameters to evaluate cardiac function, which implied that septic patients with myocardial dysfunction might have a better improvement of cardiac function by levosimendan than dobutamine (random effects, SMD = 1.05 [0.69,1.41]; I2 = 67%, P < 0.01). This study suggested a significant improvement of CI, LVSWI, and decrease of blood lactate in septic patients with myocardial dysfunction in ICU after 24-h administration of levosimendan than dobutamine. However, the administration of levosimendan has neither an impact on mortality nor LVEF. Septic patients with myocardial dysfunction may partly benefit from levosimendan than dobutamine, mainly embodied in cardiac function improvement.

Vasopressor and inotrope treatment for septic shock: An umbrella review of reviews

PURPOSE

To review the characteristics, findings and quality of systematic reviews (SRs) on the effect of any vasopressor/inotrope on outcomes in adult patients with sepsis compared with either no treatment, another vasopressor or inotrope or fluids.

MATERIALS AND METHODS

We systematically searched Cochrane Central Register of Controlled Trials, PubMed and Embase (January 1993-March 2021). Descriptive statistics were used.

RESULTS

Among the 28 SRs identified, mortality was the primary outcome in most (26/28) and mortality was usually (23/28) studied using randomised controlled trials (RCTs). Fifteen SRs focused exclusively on patients with sepsis or septic shock. Sepsis and septic shock were always grouped for the analysis. Publication bias was consistently low when studied. The most consistent findings were a survival advantage with norepinephrine versus dopamine, which disappeared in analyses restricted to 28-day mortality, and more arrhythmias with dopamine. However, these analyses were dominated by a single study. Only 2 SRs were judged to be of moderate-high quality. Lack of blinding and attrition bias may have affected the outcomes.

CONCLUSIONS

The quality of SRs on the effect of vasopressors/inotropes on the outcomes of adult patients with sepsis can be improved, but high-quality, multicenter, RCTs should be preferred to additional SRs on this topic.

Silencing Cardiac Troponin I-Interacting Kinase Reduces Lipopolysaccharide-Induced Sepsis-Induced Myocardial Dysfunction in Rat by Regulating Apoptosis-Related Proteins

The aim of this study was to investigate the effect of cardiac troponin I-interacting kinase (TNNI3K) on sepsis-induced myocardial dysfunction (SIMD) and further explore the underlying molecular mechanisms. In this study, a lipopolysaccharide- (LPS-) induced myocardial injury model was used. qRT-PCR was performed to detect the mRNA expression of TNNI3K. Western blot was conducted to quantitatively detect the expression of TNNI3K and apoptosis-related proteins (Bcl-2, Bax, and caspase-3). ELISA was performed to detect the content of lactate dehydrogenase (LDH) and creatine kinase (CK). TUNEL assay was used to detect the apoptosis of H9C2 cells. In LPS-induced H9C2 cells, TNNI3K was up regulated. Besides, the CK activity, the content of LDH, and the apoptosis of H9C2 cells were significantly increased after treatment with LPS. Silencing TNNI3K decreased the LDH release activity and CK activity and inhibited apoptosis of H9C2 cell. Further research illustrated that si-TNNI3K promoted the protein expression of Bcl-2 and decreased the protein expression of Bax and cleaved caspase-3. The study concluded that TNNI3K was upregulated in LPS-induced H9C2 cells. Importantly, functional research findings indicated that silencing TNNI3K alleviated LPS-induced H9C2 cell injury by regulating apoptosis-related proteins.

Current use of inotropes in circulatory shock

Background

Treatment decisions on critically ill patients with circulatory shock lack consensus. In an international survey, we aimed to evaluate the indications, current practice, and therapeutic goals of inotrope therapy in the treatment of patients with circulatory shock.

Methods

From November 2016 to April 2017, an anonymous web-based survey on the use of cardiovascular drugs was accessible to members of the European Society of Intensive Care Medicine (ESICM). A total of 14 questions focused on the profile of respondents, the triggering factors, first-line choice, dosing, timing, targets, additional treatment strategy, and suggested effect of inotropes. In addition, a group of 42 international ESICM experts was asked to formulate recommendations for the use of inotropes based on 11 questions.

Results

A total of 839 physicians from 82 countries responded. Dobutamine was the first-line inotrope in critically ill patients with acute heart failure for 84% of respondents. Two-thirds of respondents (66%) stated to use inotropes when there were persistent clinical signs of hypoperfusion or persistent hyperlactatemia despite a supposed adequate use of fluids and vasopressors, with (44%) or without (22%) the context of low left ventricular ejection fraction. Nearly half (44%) of respondents stated an adequate cardiac output as target for inotropic treatment. The experts agreed on 11 strong recommendations, all of which were based on excellent (> 90%) or good (81–90%) agreement. Recommendations include the indications for inotropes (septic and cardiogenic shock), the choice of drugs (dobutamine, not dopamine), the triggers (low cardiac output and clinical signs of hypoperfusion) and targets (adequate cardiac output) and stopping criteria (adverse effects and clinical improvement).

Conclusion

Inotrope use in critically ill patients is quite heterogeneous as self-reported by individual caregivers. Eleven strong recommendations on the indications, choice, triggers and targets for the use of inotropes are given by international experts. Future studies should focus on consistent indications for inotrope use and implementation into a guideline for circulatory shock that encompasses individualized targets and outcomes.

Identification of diphenylalkylisoxazol-5-amine scaffold as novel activator of cardiac myosin

To identify novel potent cardiac myosin activator, a series of diphenylalkylisoxazol-5-amine compounds 4-7 have been synthesized and evaluated for cardiac myosin ATPase activation. Among the 37 compounds, 4a (CMA at 10 µM = 81.6%), 4w (CMA at 10 µM = 71.2%) and 6b (CMA at 10 µM = 67.4%) showed potent cardiac myosin activation at a single concentration of 10 µM. These results suggested that the introduction of the amino-isoxazole ring as a bioisostere for urea group is acceptable for the cardiac myosin activation. Additional structure-activity relationship (SAR) studies were conducted. Para substitution (-Cl, -OCH₃, -SO₂N(CH₃)₂) to the phenyl rings or replacement of a phenyl ring with a heterocycle (pyridine, piperidine and tetrahydropyran) appeared to attenuate cardiac myosin activation at 10 µM. Additional hydrogen bonding acceptor next to the amino group of the isoxazoles did not enhance the activity. The potent isoxazole compounds showed selectivity for cardiac myosin activation over skeletal and smooth muscle myosin, and therefore these potent and selective isoxazole compounds could be considered as a new series of cardiac myosin ATPase activators for the treatment of systolic heart failure.

[Latest treatments for septic shock and the current state of research]

The treatment of septic shock is a medical emergency. International guidelines advise immediate care and the first hour is generally critical. It is an emergency on both an etiological and symptomatic level.

Sirt3 is a novel target to treat sepsis induced myocardial dysfunction by acetylated modulation of critical enzymes within cardiac tricarboxylic acid cycle

Sepsis induced myocardial dysfunction (SIMD) results in high morbidity and mortality. However, the effective therapeutic strategies for SIMD treatment remain limited. Sirt3 is the main mitochondrial Sirtuin member and is a key modulator of mitochondrial metabolism and function. In this study, we aimed to investigate the effect and mechanism of Sirt3 on SIMD. SIMD was induced by 20 mg/kg Lipopolysaccharides (LPS) injection for 6 h in mice. Sepsis could induce the reduction of cardiac Sirt3 expression and global deficiency of Sirt3 exacerbated cardiac function. Quantitative acetyl-proteomics and cardiac metabolomics analysis revealed that loss of Sirt3 led to hyper-acetylation of critical enzymes within cardiac tricarboxylic acid (TCA) cycle and generation of lactate and NADH, subsequently promotion of cardiac dysfunction after sepsis. Additionally, to evaluate whether Emodin could be utilized as a potential Sirt3 modulator to treat SIMD, male wild type mice (WT mice) or global Sirt3 deficient mice (Sirt3^-/- mice) were intraperitoneally injected with 40 mg/kg Emodin for 5 days followed by 20 mg/kg LPS administration for another 6 h and observed that exogenous administration of Emodin could attenuate myocardial dysfunction in septic WT mice. However, septic Sirt3^-/- mice can not gain benefit on cardiac performance from Emodin infusion. In conclusion, this study presented the protective role of Sirt3 targeting SIMD, which may provide a potential novel approach to maintain normal cardiac performance after sepsis.

Inodilators in septic shock: should these be used?

Septic shock involves a complex interaction between abnormal vasodilation, relative and/or absolute hypovolemia, myocardial dysfunction, and altered blood flow distribution to the tissues. Fluid administration, vasopressor support and inotropes, represent fundamental pieces of quantitative resuscitation protocols directed to assist the restoration of impaired tissue perfusion during septic shock. Indeed, current recommendations on sepsis management include the use of inotropes in the case of myocardial dysfunction, as suggested by a low cardiac output, increased filling pressures, or persisting signals of tissue hypoperfusion despite an adequate correction of intravascular volume and mean arterial pressure by fluid administration and vasopressor support. Evidence supporting the use of inotropes in sepsis and septic shock is mainly based on physiological studies. Most of them suggest a beneficial effect of inotropes on macro hemodynamics especially when sepsis coexists with myocardial dysfunction; others, however, have demonstrated variable results on regional splanchnic circulation, while others suggest favorable effects on microvascular distribution independently of its impact on cardiac output. Conversely, impact of inodilators on clinical outcomes in this context has been more controversial. Use of dobutamine has not been consistently related with more favorable clinical results, while systematic administration of levosimendan in sepsis do not prevent the development of multiorgan dysfunction, even in patients with evidence of myocardial dysfunction. Nevertheless, a recent metanalysis of clinical studies suggests that cardiovascular support regimens based on inodilators in sepsis and septic shock could provide some beneficial effect on mortality, while other one corroborated such effect on mortality specially in patients with proved lower cardiac output. Thus, using or not inotropes during sepsis and septic shock remains as controversy matter that deserves more research efforts.

Cardiogenic Shock: Reflections at the Crossroad Between Perfusion, Tissue Hypoxia, and Mitochondrial Function

Cardiogenic shock is classically defined by systemic hypotension with evidence of hypoperfusion and end organ dysfunction. In modern practice, however, these metrics often incompletely describe cardiogenic shock because patients present with more advanced cardiovascular disease and greater degrees of multiorgan dysfunction. Understanding how perfusion, congestion, and end organ dysfunction contribute to hypoxia at the cellular level are central to the diagnosis and management of cardiogenic shock. Although, in clinical practice, increased lactate level is often equated with hypoxia, several other factors might contribute to an elevated lactate level including mitochondrial dysfunction, impaired hepatic and renal clearance, as well as epinephrine use. To this end, we present the evidence underlying the value of lactate to pyruvate ratio as a potential discriminator of cellular hypoxia. We will then discuss the physiological implications of hypoxia and congestion on hepatic, intestinal, and renal physiology. Organ-specific susceptibility to hypoxia is presented in the context of their functional architecture. We discuss how the concepts of contractile reserve, fluid responsiveness, tissue oxygenation, and cardiopulmonary interactions can help personalize the management of cardiogenic shock. Finally, we highlight the limitations of using lactate for tailoring therapy in cardiogenic shock.

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.

Sepsis-induced myocardial dysfunction

PURPOSE OF REVIEW

Sepsis leads to a complex intramyocardial inflammatory response that results in sepsis-induced myocardial dysfunction. Here, recent findings are reviewed in a physiologic context.

RECENT FINDINGS

Decreased systolic contractility during sepsis limits ventricular ejection and stroke volume. Initially, this effect is compensated for by increased diastolic filling during volume resuscitation. Reduced afterload due to arterial vasodilation also compensates so that cardiac output can be maintained or increased. Recent results recognize the importance of diastolic dysfunction, reduced ventricular diastolic compliance that impedes ventricular filling. Diastolic dysfunction becomes increasingly important as severity of septic shock increases. When impaired ventricular ejection is coupled with limited diastolic filling, stroke volume must decrease. Accordingly, diastolic dysfunction is more closely related to mortality than systolic dysfunction. Recent trials of beta-adrenergic agonists and levosimendan have been disappointing, while approaches to modulating the intramyocardial inflammatory response show promise.

SUMMARY

Sepsis-induced myocardial dysfunction is increasingly recognized as a major contributor to outcome of septic shock. Significant strides have been made in understanding the intramyocardial inflammatory response that causes myocardial dysfunction. A number of novel approaches show promise by modulating the intramyocardial inflammatory response.

Levosimendan for Perioperative Cardioprotection: Myth or Reality?

BACKGROUND

Levosimendan is a calcium sensitizer drug causing increased contractility in the myocardium and vasodilation in the vascular system. It is mainly used for the therapy of acute decompensated heart failure. Several studies on animals and humans provided evidence of the cardioprotective properties of levosimendan including preconditioning and anti-apoptotic. In view of these favorable effects, levosimendan has been tested in patients undergoing cardiac surgery for the prevention or treatment of low cardiac output syndrome. However, initial positive results from small studies have not been confirmed in three recent large trials.

AIM

To summarize levosimendan mechanisms of action and clinical use and to review available evidence on its perioperative use in a cardiac surgery setting.

METHODS

We searched two electronic medical databases for randomized controlled trials studying levosimendan in cardiac surgery patients, ranging from January 2000 to August 2017. Metaanalyses, consensus documents and retrospective studies were also reviewed.

RESULTS

In the selected interval of time, 54 studies on the use of levosimendan in heart surgery have been performed. Early small size studies and meta-analyses have suggested that perioperative levosimendan infusion could diminish mortality and other adverse outcomes (i.e. intensive care unit stay and need for inotropic support). Instead, three recent large randomized controlled trials (LEVO-CTS, CHEETAH and LICORN) showed no significant survival benefits from levosimendan. However, in LEVO-CTS trial, prophylactic levosimendan administration significantly reduced the incidence of low cardiac output syndrome.

CONCLUSIONS

Based on most recent randomized controlled trials, levosimendan, although effective for the treatment of acute heart failure, can't be recommended as standard therapy for the management of heart surgery patients. Further studies are needed to clarify whether selected subgroups of heart surgery patients may benefit from perioperative levosimendan infusion.