Levosimendan Versus Intra-aortic Balloon Pump in High-Risk Cardiac Surgery Patients

Comparison of Postoperative Outcomes Between Intra-aortic Balloon Pump and Levosimendan in Patients Undergoing Coronary Artery Bypass Graft: A Systematic Review and Meta-Analysis

This study was conducted to compare the postoperative outcomes between intra-aortic balloon pump (IABP) and levosimendan in patients undergoing coronary artery bypass graft (CABG) surgery. This meta-analysis was conducted following the recommendations of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). For this meta-analysis, a literature search was performed on PubMed, Cochrane Central Register of Controlled Trials, and EMBASE from inception to July 15, 2023. Keywords used to search for relevant articles included "intra-aortic balloon," "levosimendan," and "cardiac surgery" along with their key terms and Medical Subject Headings (MeSH) terms. Outcomes assessed in this study included postoperative outcomes like all-cause mortality, postoperative arrhythmias, need for inotropic support, length of intensive care unit stay (ICU) in days, and duration of mechanical ventilation in hours. Other outcomes included two-hour, six-hour, and 24-hour postoperative central venous pressure (CVP), mean atrial pressure (MAP), and heart rate (HR). A total of eight studies were included in the pooled analysis. The pooled results found that the length of ICU stay and the duration of mechanical ventilation were significantly higher in patients receiving IABP. Additionally, the findings of this meta-analysis showed a higher need for inotropic support in patients receiving IABP compared to patients receiving levosimendan but the difference was statistically insignificant. However, no significant differences were found between the two groups in terms of mortality and arrhythmias. In conclusion, patients treated with levosimendan exhibited significant advantages, as they experienced shorter ICU stays and reduced duration of mechanical ventilation compared to the IABP group and less requirement for inotropic support.

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.

Perioperative Use of Levosimendan Improves Clinical Outcomes in Patients After Cardiac Surgery: A Systematic Review and Meta-Analysis

Severe postoperative complications can affect cardiac surgery patients. Levosimendan is a novel calcium sensitizer commonly administered after cardiac surgery. However, the patient benefits are controversial. PubMed, Embase, and the Cochrane library were systematically searched for randomized controlled trials comparing levosimendan with control in adult cardiac surgery patients. Twenty-five studies (3247 patients) were included. Pooled data indicated that levosimendan reduced mortality after cardiac surgery [odds ratio (OR) 0.63, 95% confidence interval (CI): 0.47-0.84, P = 0.001]. However, this reduction was restricted to patients with low (<50%) left ventricular ejection fraction (OR 0.49, 95% CI: 0.35-0.70, P = 0.0001). It significantly reduced the incidence of postoperative acute kidney injury (OR 0.55, 95% CI: 0.41-0.74, P < 0.0001) and renal replacement therapy use (OR 0.56, 95% CI: 0.39-0.80, P = 0.002). Moreover, levosimendan significantly shortened the duration of the intensive care unit stay (weighted mean differences -0.49 day, 95% CI: -0.75 to -0.24, P = 0.0002) and mechanical ventilation use (weighted mean differences -2.30 hours, 95% CI: -3.76 to -0.84, P = 0.002). In conclusion, levosimendan reduced the mortality in patients with low left ventricular ejection fraction and decreased the incidence of acute renal injury and renal replacement therapy use. In addition, it shortened the duration of the intensive care unit stay and mechanical ventilation use.

Use of Levosimendan in Cardiac Surgery: An Update After the LEVO-CTS, CHEETAH, and LICORN Trials in the Light of Clinical Practice

Levosimendan is a calcium sensitizer and adenosine triphosphate-dependent potassium channel opener, which exerts sustained hemodynamic, symptomatic, and organ-protective effects. It is registered for the treatment of acute heart failure, and when inotropic support is considered appropriate. In the past 15 years, levosimendan has been widely used in clinical practice and has also been tested in clinical trials to stabilize at-risk patients undergoing cardiac surgery. Recently, 3 randomized, placebo-controlled, multicenter studies (LICORN, CHEETAH, and LEVO-CTS) have been published reporting on the perioperative use of levosimendan in patients with compromised cardiac ventricular function. Taken together, many smaller trials conducted in the past suggested beneficial outcomes with levosimendan in perioperative settings. By contrast, the latest 3 studies were neutral or inconclusive. To understand the reasons for such dissimilarity, a group of experts from Austria, Belgium, Finland, France, Germany, Italy, Switzerland, and Russia, including investigators from the 3 most recent studies, met to discuss the study results in the light of both the previous literature and current clinical practice. Despite the fact that the null hypothesis could not be ruled out in the recent multicenter trials, we conclude that levosimendan can still be viewed as a safe and effective inodilator in cardiac surgery.

Prophylactic preoperative levosimendan for off-pump coronary artery bypass grafting in patients with left ventricular dysfunction: Single-centered randomized prospective study

Background:

Off-pump coronary artery bypass surgery (OPCAB) is often complicated by hemodynamic instability, especially in patients with prior left ventricular (LV) dysfunction and appropriate choice of inotrope plays a vital role in perioperative management of these patients.

Aim and Objective:

To study hemodynamic effects and immediate outcome of prophylactic infusion of levosimendan in patients with the LV dysfunction undergoing OPCAB surgery and whether this strategy helps in successful conduct of OPCAB surgery.

Materials and Methods:

After Institutional Ethics Committee approval, 60 patients posted for elective OPCAB surgery were randomly divided into two groups (n = 30 each). Patients with the LV ejection fraction <30% were included. Study group was started on injection levosimendan (@ 0.1 μg/kg/min) in the previous night before surgery and continued for 24 h including intraoperative period. Hemodynamic monitoring included heart rate, invasive blood pressure, cardiac index (CI), pulmonary capillary wedge pressure (PCWP), pulse oximetry, and arterial blood gases with serum lactates at as T0 (baseline), T1 (15 min after obtuse marginal and/or PDA anastomoses), T2 (at end of surgery), T3 (6 h after surgery in Intensive Care Unit [ICU]), T4 (12 h after surgery), and T5 (24 h after surgery in ICU). Vasopressor was added to maintain mean arterial pressure >60 mmHg. Chi-square/Fisher's exact/Mid P exact test and Student's t-tests were applied for categorical and continuous data.

Results:

CI was greater and PCWP reduced significantly in Group L during intraoperative and early postoperative period. Serum lactate concentration was lower in patients pretreated with levosimendan. Incidence of postoperative atrial fibrillation (POAF) (36.6 vs. 6.6%; P = 0.01), low cardiac output syndrome (LCOS) (30% vs. 6%; P = 0.02), and acute kidney injury (23.3% vs. 6.7%; P = 0.04) was less in Group L. Three patients (10%) in control group required conversion to cardiopulmonary bypass (CPB) as compared to none in the study group. There was no difference regarding ICU or hospital stay and mortality in both groups.

Conclusion:

Preoperative levosimendan helps in successful conduct of OPCAB and reduces the incidence of LCOS, POAF, conversion to CPB, and requirement of intra-aortic balloon pump.

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.

Natriuretic Peptides in Cardiac Anesthesia and Intensive Care

Natriuretic peptides, predominantly B-type, are widely used in cardiology as prognostic and diagnostic biomarkers or, much less often, as a substantive treatment tool. They are hormones that are produced mainly in the myocardium in response to overload and ischemia, and their level quite accurately reflects the degree of myocardial dysfunction. Although their use in cardiac anesthesia and intensive care setting seems to be very beneficial for assessing the risk of acute disturbance of myocardial function or its laboratory monitoring, the actual significance of natriuretic peptides in this area is not yet recognized. This is due to the lack of clear diagnostic and prognostic values for these biomarkers supported by high-quality researches. On the basis of the available data, main advantages, existing difficulties, and most effective ways of using natriuretic peptides for determining the risk of heart surgery and assessing the severity of sepsis, pneumonia, and other critical conditions have been discussed in this review. In addition, the expediency of using natriuretic peptides as target parameters for goal-oriented therapy and as a substantive tool for treatment is considered.

Levosimendan in Patients with Left Ventricular Dysfunction Undergoing Cardiac Surgery: An Update Meta-Analysis and Trial Sequential Analysis

BACKGROUND

Recent studies suggest that levosimendan does not provide mortality benefit in patients with low cardiac output syndrome undergoing cardiac surgery. These results conflict with previous findings. The aim of the current study is to assess whether levosimendan reduces postoperative mortality in patients with impaired left ventricular function (mean EF ≤ 40%) undergoing cardiac surgery.

METHODS

We conducted a comprehensive search of PubMed, EMBASE, and Cochrane Library Database through November 20, 2017. Inclusion criteria were random allocation to treatment with at least one group receiving levosimendan and another group receiving placebo or other treatments and cardiac surgery patients with a left ventricular ejection fraction of 40% or less. The primary endpoint was postoperative mortality. Secondary outcomes were cardiac index, pulmonary capillary wedge pressure (PCWP), length of intensive care unit (ICU) stay, postoperative atrial fibrillation, and postoperative renal replacement therapy. We performed trial sequential analysis (TSA) to evaluate the reliability of the primary endpoint.

RESULTS

Data from 2,152 patients in 15 randomized clinical trials were analyzed. Pooled results demonstrated a reduction in postoperative mortality in the levosimendan group [RR = 0.53, 95% CI (0.38-0.73), I2 = 0]. However, the result of TSA showed that the conclusion may be a false positive. Secondary outcomes demonstrated that PCWP, postoperative renal replacement therapy, and length of ICU stay were significantly reduced. Cardiac index was greater in the levosimendan group. No difference was found in the rate of postoperative atrial fibrillation.

CONCLUSIONS

Levosimendan reduces the rate of death and other adverse outcomes in patients with low ejection fraction who were undergoing cardiac surgery, but results remain inconclusive. More large-volume randomized clinical trials (RCTs) are warranted.

Inotropic agents and vasodilator strategies for the treatment of cardiogenic shock or low cardiac output syndrome

BACKGROUND

Cardiogenic shock (CS) and low cardiac output syndrome (LCOS) as complications of acute myocardial infarction (AMI), heart failure (HF) or cardiac surgery are life-threatening conditions. While there is a broad body of evidence for the treatment of people with acute coronary syndrome under stable haemodynamic conditions, the treatment strategies for people who become haemodynamically unstable or develop CS remain less clear. We have therefore summarised here the evidence on the treatment of people with CS or LCOS with different inotropic agents and vasodilative drugs. This is the first update of a Cochrane review originally published in 2014.

OBJECTIVES

To assess efficacy and safety of cardiac care with positive inotropic agents and vasodilator strategies in people with CS or LCOS due to AMI, HF or cardiac surgery.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and CPCI-S Web of Science in June 2017. We also searched four registers of ongoing trials and scanned reference lists and contacted experts in the field to obtain further information. No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials in people with myocardial infarction, heart failure or cardiac surgery complicated by cardiogenic shock or LCOS.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We identified 13 eligible studies with 2001 participants (mean or median age range 58 to 73 years) and two ongoing studies. We categorised studies into eight comparisons, all against cardiac care and additional other active drugs or placebo. These comparisons investigated the efficacy of levosimendan versus dobutamine, enoximone or placebo, epinephrine versus norepinephrine-dobutamine, amrinone versus dobutamine, dopexamine versus dopamine, enoximone versus dopamine and nitric oxide versus placebo.All trials were published in peer-reviewed journals, and analysis was done by the intention-to-treat (ITT) principle. Twelve of 13 trials were small with few included participants. Acknowledgement of funding by the pharmaceutical industry or missing conflict of interest statements emerged in five of 13 trials. In general, confidence in the results of analysed studies was reduced due to serious study limitations, very serious imprecision or indirectness. Domains of concern, which show a high risk of more than 50%, include performance bias (blinding of participants and personnel) and bias affecting the quality of evidence on adverse events.Levosimendan may reduce short-term mortality compared to a therapy with dobutamine (RR 0.60, 95% CI 0.37 to 0.95; 6 studies; 1776 participants; low-quality evidence; NNT: 16 (patients with moderate risk), NNT: 5 (patients with CS)). This initial short-term survival benefit with levosimendan vs. dobutamine is not confirmed on long-term follow up. There is uncertainty (due to lack of statistical power) as to the effect of levosimendan compared to therapy with placebo (RR 0.48, 95% CI 0.12 to 1.94; 2 studies; 55 participants, very low-quality evidence) or enoximone (RR 0.50, 95% CI 0.22 to 1.14; 1 study; 32 participants, very low-quality evidence).All comparisons comparing other positive inotropic, inodilative or vasodilative drugs presented uncertainty on their effect on short-term mortality with very low-quality evidence and based on only one RCT. These single studies compared epinephrine with norepinephrine-dobutamine (RR 1.25, 95% CI 0.41 to 3.77; 30 participants), amrinone with dobutamine (RR 0.33, 95% CI 0.04 to 2.85; 30 participants), dopexamine with dopamine (no in-hospital deaths from 70 participants), enoximone with dobutamine (two deaths from 40 participants) and nitric oxide with placebo (one death from three participants).

AUTHORS' CONCLUSIONS

Apart from low quality of evidence data suggesting a short-term mortality benefit of levosimendan compared with dobutamine, at present there are no robust and convincing data to support a distinct inotropic or vasodilator drug-based therapy as a superior solution to reduce mortality in haemodynamically unstable people with cardiogenic shock or LCOS.Considering the limited evidence derived from the present data due to a generally high risk of bias and imprecision, it should be emphasised that there remains a great need for large, well-designed randomised trials on this topic to close the gap between daily practice in critical care medicine and the available evidence. It seems to be useful to apply the concept of 'early goal-directed therapy' in cardiogenic shock and LCOS with early haemodynamic stabilisation within predefined timelines. Future clinical trials should therefore investigate whether such a therapeutic concept would influence survival rates much more than looking for the 'best' drug for haemodynamic support.

Rationale and design of the multicenter randomized trial investigating the effects of levosimendan pretreatment in patients with low ejection fraction (≤40 %) undergoing CABG with cardiopulmonary bypass (LICORN study)

Background

Patients with a left ventricular ejection fraction (LVEF) of less than 40 % are at high risk of developing postoperative low cardiac output syndrome (LCOS). Despite actual treatments (inotropic agents and/or mechanical assist devices), the mortality rate of such patients remains very high (13 to 24 %). The LICORN trial aims at assessing the efficacy of a preoperative infusion of levosimendan in reducing postoperative LCOS in patients with poor LVEF undergoing coronary artery bypass grafting (CABG).

Methods/Design

LICORN study is a multicenter, randomized double-blind, placebo-controlled trial in parallel groups. 340 patients with LVEF ≤40 %, undergoing CABG will be recruited from 13 French hospitals. The study drug will be started after anaesthesia induction and infused over 24 h (0.1 μg/kg/min).

The primary outcome (postoperative LCOS) is evaluated using a composite criterion composed of: 1) need for inotropic agents beyond 24 h following discontinuation of the study drug; 2) need for post-operative mechanical assist devices or failure to wean from these techniques when inserted pre-operatively; 3) need for renal replacement therapy. Secondary outcomes include: 1) mortality at Day 28 and Day 180; 2) each item of the composite criterion of the primary outcome; 3) the number of “ventilator-free” days and “out of intensive care unit” days at Day 28.

Discussion

The usefulness of levosimendan in the perioperative period has not yet been documented with a high level of evidence. The LICORN study is the first randomized controlled trial evaluating the clinical value of preoperative levosimendan in high risk cardiac surgical patients undergoing CABG.

Trial registration number

NCT02184819 (ClinicalTrials.gov).

Assessing the effect of preoperative levosimendan on renal function in patients with right ventricular dysfunction

The Acute Kidney Injury Network (AKIN) classification considers SCr values, urea and urine output in order to improve timely diagnose ARF and improve patient prognosis by early treatment. Preoperative levosimendan is a new way for cardiac and kidney protection, we try to evaluate this drug in fifteen patients comparing values of AKIN scale parameters pre and post cardiac surgery in patients with right ventricle dysfunction.

A Randomized Blinded Study of the Left Ventricular Myocardial Performance Index Comparing Epinephrine to Levosimendan following Cardiopulmonary Bypass

BACKGROUND

The objective was to evaluate the effect of epinephrine and levosimendan on the left ventricle myocardial performance index in patients undergoing on-pump coronary artery by-pass grafting (CABG).

METHODS

In a double-blind, randomized clinical trial, 81 patients (age: 45-65 years) of both genders were randomly divided to receive either epinephrine at a dosage of 0.06 mcg.kg(1).min(-1) (epinephrine group, 39 patients) or levosimendan at 0.2 mcg.kg(1).min(-1) (levosimendan group, 42 patients) during the rewarming of cardiopulmonary by-pass (CPB). Hemodynamic data were collected 30 minutes after tracheal intubation, before chest open (pre-CPB) and 10 minutes after termination of protamine (post-CPB). As the primary outcome, we evaluated the left ventricle myocardial performance index by the Doppler echocardiography. The myocardial performance index is the sum of the isovolumetric contraction time and the isovolumetric relaxation time, divided by the ejection time. Secondary outcomes were systolic and diastolic evaluations of the left ventricle and postoperative troponin I and MB-CK levels.

RESULTS

Of the 81 patients allocated to the research, we excluded 2 patients in the epinephrine group and 6 patients in the levosimendan group because they didn't wean from CPB in the first attempt. There was no statistical difference between the groups in terms of patient characteristics, risk factors, or CPB time. The epinephrine group had a lower left ventricle myocardial performance index (p = 0.0013), higher cardiac index (p = 0.03), lower systemic vascular resistance index (p = 0.01), and higher heart rate (p = 0.04) than the levosimendan group at the post-CPB period. There were no differences between the groups in diastolic dysfunction. The epinephrine group showed higher incidence of weaning from CPB in the first attempt (95% vs 85%, p = 0.0001) when compared to the levosimendan group and the norepinephrine requirement was higher in the levosimenandan group than epinephrine group (16% vs. 47%; p = 0.005) in post-CPB period. Twenty-four hours after surgery, the plasma levels of troponin I (epinephrine group: 4.5 ± 5.7 vs. levosimendan group: 2.5 ± 3.2 g/dl; p = 0.09) and MB-CK (epinephrine group: 50.7 ± 31 vs. levosimendan group: 37 ± 17.6 g/dl; p = 0.08) were not significantly different between the two groups.

CONCLUSION

When compared to levosimendan, patients treated with epinephrine had a lower left ventricle myocardial performance index in the immediate post-CPB period, encouraging an efficient weaning from CPB in patients undergoing on-pump CABG.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01616069.

Levosimendan Reduces Mortality in Adults with Left Ventricular Dysfunction Undergoing Cardiac Surgery: A Systematic Review and Meta-analysis

INTRODUCTION

Levosimendan is implemented in patients with low cardiac output after cardiac surgery. However, the strength of evidence is limited by randomized controlled trials enrolling a small number of patients. Hence we have conducted a systematic review to determine the role of levosimendan in adult cardiac surgery.

METHODS

PUBMED, WoS, Cochrane database, and SCOPUS were systematically queried to identify original English language peer-reviewed literature (inception-October 2014) comparing clinical results of adult cardiac surgery between levosimendan and control. Pooled odds ratio (OR) was calculated using the Peto method; p < 0.05 is significant; results are presented within 95% confidence intervals. Continuous data was compared using standardized mean difference/mean difference.

RESULTS

Fourteen studies were included in the analysis. Levosimendan reduced early mortality in patients with reduced ejection fraction (5.5% vs. 9.1%) (OR 0.48 [0.23-0.76]; p = 0.004). This result was confirmed using sensitivity analysis. Postoperative acute renal failure was lower with levosimendan therapy (7.4% vs. 11.5%). Intensive care unit stay was shorter in the levosimendan cohort comparable in both groups (standardized mean difference -0.31 [-0.53, -0.09]; p = 0.006; I(2)  = 33.6%). Levosimendan-treated patients stayed 1.01 (1.61-0.42) days shorter when compared to control (p = 0.001).

CONCLUSION

Our meta-analysis demonstrates that Levosimendan improves clinical outcomes in patients with left ventricular dysfunction undergoing cardiac surgery. Results of the ongoing multicenter randomized controlled trial are awaited to provide more conclusive evidence regarding the benefit of this drug.

Inotropic agents and vasodilator strategies for acute myocardial infarction complicated by cardiogenic shock or low cardiac output syndrome

BACKGROUND

The recently published German-Austrian S3 Guideline for the treatment of infarct related cardiogenic shock (CS) revealed a lack of evidence for all recommended therapeutic measures.

OBJECTIVES

To determine the effects in terms of efficacy, efficiency and safety of cardiac care with inotropic agents and vasodilator strategies versus placebo or against each other for haemodynamic stabilisation following surgical treatment, interventional therapy (angioplasty, stent implantation) and conservative treatment (that is no revascularization) on mortality and morbidity in patients with acute myocardial infarction (AMI) complicated by CS or low cardiac output syndrome (LCOS).

SEARCH METHODS

We searched CENTRAL, MEDLINE (Ovid), EMBASE (Ovid) and ISI Web of Science, registers of ongoing trials and proceedings of conferences in January 2013. Reference lists were scanned and experts in the field were contacted to obtain further information. No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials in patients with AMI complicated by CS or LCOS.

DATA COLLECTION AND ANALYSIS

Data collection and analysis were performed according to the published protocol. All trials were analysed individually. Hazard ratios (HRs) and odds ratios with 95% confidence intervals (CI) were extracted but not pooled because of high heterogeneity between the control group interventions.

MAIN RESULTS

Four eligible, very small studies were identified from a total of 4065 references. Three trials with high overall risk of bias compared levosimendan to standard treatment (enoximone or dobutamine) or placebo. Data from a total of 63 participants were included in our comparisons, 31 were treated with levosimendan and 32 served as controls. Levosimendan showed an imprecise survival benefit in comparison with enoximone based on a very small trial with 32 participants (HR 0.33; 95% CI 0.11 to 0.97). Results from the other similarly small trials were too imprecise to provide any meaningful information about the effect of levosimendan in comparison with dobutamine or placebo. Only small differences in haemodynamics, length of hospital stay and the frequency of major adverse cardiac events or adverse events overall were found between study groups.Only one small randomised controlled trial with three participants was found for vasodilator strategies (nitric oxide gas versus placebo) in AMI complicated by CS or LCOS. This study was too small to draw any conclusions on the effects on our key outcomes.

AUTHORS' CONCLUSIONS

At present there are no robust and convincing data to support a distinct inotropic or vasodilator drug based therapy as a superior solution to reduce mortality in haemodynamically unstable patients with CS or low cardiac output complicating AMI.