RETRACTED: A Randomized Trial Evaluating Different Modalities of Levosimendan Administration in Cardiac Surgery Patients With Myocardial Dysfunction

The Perioperative Use of Levosimendan as a Means of Optimizing the Surgical Outcome in Patients with Severe Heart Insufficiency Undergoing Cardiac Surgery

BACKGROUND

Postoperative myocardial dysfunction following cardiac surgery is a relatively common occurrence. Levosimendan, a calcium sensitizer and inotropic drug, has shown potential in improving outcomes for patients with low preoperative ejection fraction (EF) and myocardial dysfunction after cardiac surgery. This study aims to evaluate the efficacy of levosimendan in optimizing the surgical outcome for such patients.

METHODS

A retrospective analysis was conducted on 314 patients with preoperative severe heart failure who underwent cardiac surgery. Among them, 184 patients received perioperative adjunctive therapy with levosimendan, while a comparable group of 130 patients received conventional treatment.

RESULTS

The use of levosimendan demonstrated several advantages in postoperative outcomes. It significantly improved short- and long-term survival rates after cardiac surgery, enhanced hemodynamic stability, reduced the requirement for inotropic support, and facilitated faster weaning from ventilator support. Patients who received levosimendan reported reduced angina and dyspnea symptoms, as well as fewer postoperative arrhythmias. Furthermore, levosimendan helped minimize myocardial injury inevitable after cardiac surgery. The levosimendan group also exhibited a notable reduction in hospital readmissions.

CONCLUSIONS

This study provides evidence of several benefits associated with the perioperative use of levosimendan. However, further prospective randomized studies are warranted to standardize and comprehensively document the other perioperative therapies, in order to validate these findings and establish stronger conclusions.

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.

Levosimendan beyond inotropy and acute heart failure: Evidence of pleiotropic effects on the heart and other organs: An expert panel position paper

Levosimendan is a positive inotrope with vasodilating properties (inodilator) indicated for decompensated heart failure (HF) patients with low cardiac output. Accumulated evidence supports several pleiotropic effects of levosimendan beyond inotropy, the heart and decompensated HF. Those effects are not readily explained by cardiac function enhancement and seem to be related to additional properties of the drug such as anti-inflammatory, anti-oxidative and anti-apoptotic ones. Mechanistic and proof-of-concept studies are still required to clarify the underlying mechanisms involved, while properly designed clinical trials are warranted to translate preclinical or early-phase clinical data into more robust clinical evidence. The present position paper, derived by a panel of 35 experts in the field of cardiology, cardiac anesthesiology, intensive care medicine, cardiac physiology, and cardiovascular pharmacology from 22 European countries, compiles the existing evidence on the pleiotropic effects of levosimendan, identifies potential novel areas of clinical application and defines the corresponding gaps in evidence and the required research efforts to address those gaps.

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

OBJECTIVE

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

DESIGN

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

SETTING

Tertiary care hospitals.

INTERVENTIONS

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

MEASUREMENTS AND MAIN RESULTS

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

CONCLUSIONS

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

Cardiopulmonary bypass and oxidative stress

The development of the cardiopulmonary bypass (CPB) revolutionized cardiac surgery and contributed immensely to improved patients outcomes. CPB is associated with the activation of different coagulation, proinflammatory, survival cascades and altered redox state. Haemolysis, ischaemia, and perfusion injury and neutrophils activation during CPB play a pivotal role in oxidative stress and the associated activation of proinflammatory and proapoptotic signalling pathways which can affect the function and recovery of multiple organs such as the myocardium, lungs, and kidneys and influence clinical outcomes. The administration of agents with antioxidant properties during surgery either intravenously or in the cardioplegia solution may reduce ROS burst and oxidative stress during CPB. Alternatively, the use of modified circuits such as minibypass can modify both proinflammatory responses and oxidative stress.

Meta-analysis of randomized trials of effect of milrinone on mortality in cardiac surgery: an update

OBJECTIVE

The long-term use of milrinone is associated with increased mortality in chronic heart failure. A recent meta-analysis suggested that it might increase mortality in patients undergoing cardiac surgery. The authors conducted an updated meta-analysis of randomized trials in patients undergoing cardiac surgery to determine if milrinone impacted survival.

DESIGN

A meta-analysis.

SETTING

Hospitals.

PARTICIPANTS

One thousand thirty-seven patients from 20 randomized trials.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Biomed, Central, PubMed, EMBASE, the Cochrane central register of clinical trials, and conference proceedings were searched for randomized trials that compared milrinone versus placebo or any other control in adult and pediatric patients undergoing cardiac surgery. Authors of trials that did not include mortality data were contacted. Only trials for which mortality data were available were included. Overall analysis showed no difference in mortality between patients receiving milrinone versus control (12/554 [2.2%] in the milrinone group v 10/483 [2.1%] in the control arm; relative risk [RR] = 1.15; 95% confidence interval [CI], 0.55-2.43; p = 0.7) or in analysis restricted to adults (11/364 [3%] in the milrinone group v 9/371 [2.4%] in the control arm; RR = 1.17; 95% CI, 0.54-2.53; p = 0.7). Sensitivity analyses in trials with a low risk of bias showed a trend toward an increase in mortality with milrinone (8/153 [5.2%] in the milrinone arm v 2/152 [1.3%] in the control arm; RR = 2.71; 95% CI, 0.82-9; p for effect = 0.10).

CONCLUSIONS

Despite theoretic concerns for increased mortality with intravenous milrinone in patients undergoing cardiac surgery, the authors were unable to confirm an adverse effect on survival. However, sensitivity analysis of high-quality trials showed a trend toward increased mortality with milrinone.

Drug-induced atrial fibrillation

Atrial fibrillation (AF) is a common cardiac arrhythmia that is associated with severe consequences, including symptoms, haemodynamic instability, increased cardiovascular mortality and stroke. While other arrhythmias such as torsades de pointes and sinus bradycardia are more typically thought of as drug induced, AF may also be precipitated by drug therapy, although ascribing causality to drug-associated AF is more difficult than with other drug-induced arrhythmias. Drug-induced AF is more likely to occur in patients with risk factors and co-morbidities that commonly co-exist with AF, such as advanced age, alcohol consumption, family history of AF, hypertension, thyroid dysfunction, sleep apnoea and heart disease. New-onset AF has been associated with cardiovascular drugs such as adenosine, dobutamine and milrinone. In addition, medications such as corticosteroids, ondansetron and antineoplastic agents such as paclitaxel, mitoxantrone and doxorubicin have been reported to induce AF. Whether bisphosphonate drugs are associated with new-onset AF remains controversial and requires further study. The potential contribution of specific drug therapy should be considered when patients present with new-onset AF.

Milrinone and mortality in adult cardiac surgery: a meta-analysis

OBJECTIVE

The authors conducted a review of randomized studies to show whether there are any increases or decreases in survival when using milrinone in patients undergoing cardiac surgery.

DESIGN

A meta-analysis.

SETTING

Hospitals.

PARTICIPANTS

Five hundred eighteen patients from 13 randomized trials.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

BioMedCentral, PubMed EMBASE, the Cochrane central register of clinical trials, and conference proceedings were searched for randomized trials that compared milrinone versus placebo or any other control in the setting of cardiac surgery that reported data on mortality. Overall analysis showed that milrinone increased perioperative mortality (13/249 [5.2%] in the milrinone group v 6/269 [2.2%] in the control arm, odds ratio [OR] = 2.67 [1.05-6.79], p for effect = 0.04, p for heterogeneity = 0.23, I(2) = 25% with 518 patients and 13 studies included). Subanalyses confirmed increased mortality with milrinone (9/84 deaths [10.7%] v 3/105 deaths [2.9%] with other drugs as control, OR = 4.19 [1.27-13.84], p = 0.02) with 189 patients and 5 studies included) but did not confirm a difference in mortality (4/165 [2.4%] in the milrinone group v 3/164 [1.8%] with placebo or nothing as control, OR = 1.27 [0.28-5.84], p = 0.76 with 329 patients and 8 studies included).

CONCLUSIONS

This analysis suggests that milrinone might increase mortality in adult patients undergoing cardiac surgery. The effect was seen only in patients having an active inotropic drug for comparison and not in the placebo subgroup. Therefore, the question remains whether milrinone increased mortality or if the control inotropic drugs were more protective.

Levosimendan and mortality after coronary revascularisation: a meta-analysis of randomised controlled trials

INTRODUCTION

Patients undergoing coronary revascularization often require inotropic support that has been associated with an increased risk for death and morbidity. The purpose of this study was to evaluate the effect of levosimendan versus control on survival after coronary revascularization.

METHODS

A systemic review and meta-analysis of the literature was carried out on published randomized controlled clinical trials that investigated the efficacy of levosimendan compared to other therapy in patients having coronary revascularisaion. The databases searched were Pubmed, EMBASE, the Cochrane Registry of Clinical Trials and the metaRegister of Controlled Trials. Studies that compared levosimendan to any other therapy for coronary revascularisation in adult humans and reported at least one outcome of interest were considered for inclusion. Both percutaneous coronary intervention and cardiac surgery were included. Data extraction was performed independently by two reviewers using predefined criteria. Relevant outcomes included mortality, cardiac index, cardiac enzymes, length of stay and post-procedural atrial fibrillation.

RESULTS

The meta-analysis included 729 patients from 17 studies. Levosimendan was associated with a mortality reduction after coronary revascularization, (19/386 in the levosimendan group vs 39/343 in the control arm) odds ratio (OR) 0.40 (95% confidence interval (CI) 0.21 to 0.76, P for overall effect 0.005, P for heterogeneity = 0.33, I2 = 12% with a total of 729 patients. Levosimendan also had a favourable effect on cardiac index (standardised mean difference 1.63, 95% CI 1.43 to 1.83, P for overall effect < 0.00001), length of intensive care stay (random effects model, mean difference - 26.18 hours 95% CI 46.20 to 6.16, P for heterogeneity < 0.00001, I2 = 95%, P for overall effect P = 0.01), reductions in the rate of atrial fibrillation (OR 0.54, 95% CI 0.36 to 0.82, P for effect = 0.004, P for heterogeneity 0.84, I2 = 0% for 465 patients) and troponin I levels group (mean difference -1.59, 95% CI 1.78 to 1.40, P for overall effect < 0.00001, P for heterogeneity < 0.00001, I2 = 95%). Limitations of this analysis are discussed.

CONCLUSIONS

Levosimendan is associated with a significant improvement in mortality after coronary revascularization. There are also improvements in several secondary endpoints. A suitably powered randomised controlled trial is required to confirm these findings and to address the unresolved questions about the timing and dosing of levosimendan.

Inotropes in cardiac patients: update 2011

PURPOSE OF REVIEW

ICU patients frequently develop low output syndromes due to cardiac dysfunction, myocardial injury, and inflammatory activation. Conventional inotropic agents seem to be useful in restoring hemodynamic parameters and improving peripheral organ perfusion, but can increase short-term and long-term mortality in these patients. Novel inotropes may be promising in the management of ICU patients, having no serious adverse effects. This review summarizes all the current knowledge about the use of conventional and new inotropic agents in various clinical entities of critically ill patients.

RECENT FINDINGS

In recent European Society of Cardiology guidelines, inotropic agents are administered in patients with low output syndrome due to impaired cardiac contractility, and signs and symptoms of congestion. The most recommended inotropes in this condition are levosimendan and dobutamine (both class of recommendation: IIa, level of evidence: B). Recent data indicate that levosimendan may be useful in postmyocardial infarction cardiac dysfunction and septic shock through increasing coronary flow and attenuating inflammatory activation, respectively. Furthermore, calcium sensitizing by levosimendan can be effectively used for weaning of mechanical ventilation in postcardiac surgery patients and has also cardioprotective effect as expressed by the absence of troponin release in this patient population. Finally, new agents, such as istaroxime and cardiac myosin activators may be safe and improve central hemodynamics in experimental models of heart failure and heart failure patients in phase II clinical trials; however, large-scale randomized clinical trials are required.

SUMMARY

In an acute cardiac care setting, short-term use of inotropic agents is crucial for the restoration of arterial blood pressure and peripheral tissue perfusion, as well as weaning of cardiosurgery. New promising agents should be tested in randomized clinical trials.

Antioxidant interventions as novel preventive strategies for postoperative atrial fibrillation

Atrial fibrillation is the most common sustained arrhythmia encountered following cardiac surgery. Although anti-arrhythmic drugs such as beta-blockers and amiodarone are recommended and used in clinical practice, the incidence of postoperative atrial fibrillation (POAF) is still very high. Recent evidence suggests oxidative stress may play an important role in the pathogenesis and perpetuation of POAF. Increased reactive oxygen species and activated atrial nicotinamide adenine dinucleotide phosphate (NADPH) oxidases after cardiac surgery are key targets for the prevention of POAF. In addition to statins, Vitamin C and E, N-acetylcysteine and carvedilol, some other anti-oxidant interventions such as thiazolidinediones, nitric oxide donor or precursor, probucol, levosimendan and NADPH oxidase inhibitors have emerged as novel strategies in the prevention of POAF.

Initial Single-Center Experience With Levosimendan Infusion for Perioperative Management of Univentricular Heart With Ductal-Dependent Systemic Circulation

The aim of this study was to evaluate the safety and the efficacy of levosimendan, a novel calcium sensitizer agent, on postoperative hemodynamic and metabolic parameters of neonates affected by single ventricle anatomy. Twenty consecutive neonates scheduled for the Norwood procedure with Blalock Taussig shunt were prospectively enrolled. All patients received an infusion of levosimendan at 0.1 μg/kg/min commencing 24 hours before surgery, and the infusion was continued for 48 hours after surgery. No side effects (intolerance to the drug, hypotension, arrhythmias) were shown. A median inotropic score (IS) of 37 was necessary to maintain a mean arterial pressure between 45 and 50 mm Hg at intensive care unit (ICU) admission: IS was significantly reduced after 72 hours ( P < .05). Brain natriuretic peptide values decreased significantly from 1210 to 459 pg/mL in 72 hours ( P < .05). Median SvO2 increased significantly from 38% to 59% during the evaluated period ( P < .05). Cerebral near-infrared spectroscopy values were close to 40% at ICU admission with a significant stable increase to 50% after 12 hours ( P < .05). Median lactate level was 13 mmol/L at ICU admission but showed a trend to a rapid and significant decrease after 12 hours ( P < .05). Median urine output was surprisingly elevated, always remaining between 5.2 and 6.2 mL/kg/h throughout the postoperative period. Survival rate was 85% at 30 days (17/20 patients) and 75% (15/20) at hospital discharge. Levosimendan infusion in a cohort of neonates with univentricular anatomy was safe and potentially beneficial on postoperative hemodynamic and metabolic parameters.

Levosimendan - a calcium sensitising agent with potential anti-arrhythmic properties

Levosimendan is a 'Ca(2+)sensitiser', which exerts its inotropic effect by increasing the affinity of troponin C for Ca(2+), directly stabilising the Ca(2+)-induced conformation of troponin C. It leads to a positive inotropic effect without impairing diastolic relaxation and causing cytosolic Ca(2+) ion overload, which might result in cardiac myocyte dysfunction, arrhythmias and cell death. Levosimendan may also have significant anti-inflammatory properties. Data from various studies suggest that levosimendan might have anti-arrhythmic effects, although the outcome of clinical trials on the effect of this agent in (for example) atrial fibrillation (AF) remains controversial. Currently, on the basis of available data, it is especially worth emphasising the potential role of this drug in the termination of AF after cardiac surgery, which significantly influences early- and long-term morbidity and mortality. This review considers the putative anti-arrhythmic properties of levosimendan and discusses the potential clinical application of such a drug.

S3 guidelines for intensive care in cardiac surgery patients: hemodynamic monitoring and cardiocirculary system

Hemodynamic monitoring and adequate volume-therapy, as well as the treatment with positive inotropic drugs and vasopressors are the basic principles of the postoperative intensive care treatment of patient after cardiothoracic surgery. The goal of these S3 guidelines is to evaluate the recommendations in regard to evidence based medicine and to define therapy goals for monitoring and therapy. In context with the clinical situation the evaluation of the different hemodynamic parameters allows the development of a therapeutic concept and the definition of goal criteria to evaluate the effect of treatment. Up to now there are only guidelines for subareas of postoperative treatment of cardiothoracic surgical patients, like the use of a pulmonary artery catheter or the transesophageal echocardiography. The German Society for Thoracic and Cardiovascular Surgery (Deutsche Gesellschaft für Thorax-, Herz- und Gefässchirurgie, DGTHG) and the German Society for Anaesthesiology and Intensive Care Medicine (Deutsche Gesellschaft für Anästhesiologie und lntensivmedizin, DGAI) made an approach to ensure and improve the quality of the postoperative intensive care medicine after cardiothoracic surgery by the development of S3 consensus-based treatment guidelines. Goal of this guideline is to assess the available monitoring methods with regard to indication, procedures, predication, limits, contraindications and risks for use. The differentiated therapy of volume-replacement, positive inotropic support and vasoactive drugs, the therapy with vasodilatators, inodilatators and calcium sensitizers and the use of intra-aortic balloon pumps will also be addressed. The guideline has been developed following the recommendations for the development of guidelines by the Association of the Scientific Medical Societies in Germany (AWMF). The presented key messages of the guidelines were approved after two consensus meetings under the moderation of the Association of the Scientific Medical Societies in Germany (AWMF).

Clinical review: practical recommendations on the management of perioperative heart failure in cardiac surgery

Acute cardiovascular dysfunction occurs perioperatively in more than 20% of cardiosurgical patients, yet current acute heart failure (HF) classification is not applicable to this period. Indicators of major perioperative risk include unstable coronary syndromes, decompensated HF, significant arrhythmias and valvular disease. Clinical risk factors include history of heart disease, compensated HF, cerebrovascular disease, presence of diabetes mellitus, renal insufficiency and high-risk surgery. EuroSCORE reliably predicts perioperative cardiovascular alteration in patients aged less than 80 years. Preoperative B-type natriuretic peptide level is an additional risk stratification factor. Aggressively preserving heart function during cardiosurgery is a major goal. Volatile anaesthetics and levosimendan seem to be promising cardioprotective agents, but large trials are still needed to assess the best cardioprotective agent(s) and optimal protocol(s). The aim of monitoring is early detection and assessment of mechanisms of perioperative cardiovascular dysfunction. Ideally, volume status should be assessed by 'dynamic' measurement of haemodynamic parameters. Assess heart function first by echocardiography, then using a pulmonary artery catheter (especially in right heart dysfunction). If volaemia and heart function are in the normal range, cardiovascular dysfunction is very likely related to vascular dysfunction. In treating myocardial dysfunction, consider the following options, either alone or in combination: low-to-moderate doses of dobutamine and epinephrine, milrinone or levosimendan. In vasoplegia-induced hypotension, use norepinephrine to maintain adequate perfusion pressure. Exclude hypovolaemia in patients under vasopressors, through repeated volume assessments. Optimal perioperative use of inotropes/vasopressors in cardiosurgery remains controversial, and further large multinational studies are needed. Cardiosurgical perioperative classification of cardiac impairment should be based on time of occurrence (precardiotomy, failure to wean, postcardiotomy) and haemodynamic severity of the patient's condition (crash and burn, deteriorating fast, stable but inotrope dependent). In heart dysfunction with suspected coronary hypoperfusion, an intra-aortic balloon pump is highly recommended. A ventricular assist device should be considered before end organ dysfunction becomes evident. Extra-corporeal membrane oxygenation is an elegant solution as a bridge to recovery and/or decision making. This paper offers practical recommendations for management of perioperative HF in cardiosurgery based on European experts' opinion. It also emphasizes the need for large surveys and studies to assess the optimal way to manage perioperative HF in cardiac surgery.

Reducing mortality in cardiac surgery with levosimendan: a meta-analysis of randomized controlled trials

OBJECTIVES

The authors performed a meta-analysis to evaluate whether levosimendan is associated with improved survival in patients undergoing cardiac surgery.

DESIGN

A meta-analysis.

SETTING

Hospitals.

PARTICIPANTS

A total of 440 patients from 10 randomized controlled studies were included in the analysis.

INTERVENTIONS

None. MEASURMENTS AND MAIN RESULTS: Four investigators independently searched BioMedCentral and PubMed. Inclusion criteria were random allocation to treatment, comparison of levosimendan versus control, and cardiac surgery patients. Exclusion criteria were duplicate publications, nonhuman experimental studies, and no mortality data. The primary endpoint was postoperative mortality. Levosimendan was associated with a significant reduction in postoperative mortality (11/235 [4.7%] in the levosimendan group v 26/205 [12.7%] in the control arm, odds ratio = 0.35 [0.18-0.71], p for effect = 0.003, p for heterogeneity = 0.22, I(2) = 27.4% with 440 patients included), cardiac troponin release, and atrial fibrillation. No difference was found in terms of myocardial infarction, acute renal failure, time on mechanical ventilation, intensive care unit, and hospital stay.

CONCLUSIONS

Levosimendan has cardioprotective effects that could result in a reduced postoperative mortality. A large randomized controlled study is warranted in this setting.