Levosimendan Versus an Intra-aortic Balloon Pump in Adult Cardiac Surgery Patients With Low Cardiac Output

The Role of Levosimendan in Patients with Decreased Left Ventricular Function Undergoing Cardiac Surgery

The postoperative low cardiac output is one of the most important complications following cardiac surgery and is associated with increased morbidity and mortality. The condition requires inotropic support to achieve adequate hemodynamic status and tissue perfusion. While catecholamines are utilised as a standard therapy in cardiac surgery, their use is limited due to increased oxygen consumption. Levosimendan is calcium sensitising inodilatator expressing positive inotropic effect by binding with cardiac troponin C without increasing oxygen demand. Furthermore, the drug opens potassium ATP (KATP) channels in cardiac mitochondria and in the vascular muscle cells, showing cardioprotective and vasodilator properties, respectively. In the past decade, levosimendan demonstrated promising results in treating patients with reduced left ventricular function when administered in peri- or post- operative settings. In addition, pre-operative use of levosimendan in patients with severely reduced left ventricular ejection fraction may reduce the requirements for postoperative inotropic support, mechanical support, duration of intensive care unit stay as well as hospital stay and a decrease in post-operative mortality. However, larger studies are needed to clarify clinical advantages of levosimendan versus conventional inotropes.

One problem two issues! Left ventricular systolic and diastolic dysfunction in aortic stenosis

Reports suggested that immediate post-aortic valve replacement (AVR); left ventricular (LV) dysfunction may be an important risk for morbidity and mortality in patients requiring positive inotropic support. Several factors have been identified as significant prognostic factors i.e., LV systolic dysfunction, LV diastolic dysfunction (LV-DD), heart failure and myocardial infarction (MI). Specific to pathophysiological changes associated with AS, markers of systolic LV function (e.g., LVEF) have been extensively studied in management, yet only a few studies have analysed the association between LV-DD and immediate post-operative LV dysfunction This review brings together the current body of evidence on this issue.

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.