Levosimendan for Hemodynamic Support after Cardiac Surgery

Impact of Perioperative Levosimendan Administration on Risk of Bleeding After Cardiac Surgery: A Meta-analysis of Randomized Controlled Trials

BACKGROUND

Levosimendan, a calcium sensitizer and potassium channel opener, has been demonstrated to improve myocardial function without increasing oxygen consumption and to show protective effects in other organs. Recently, a prospective, randomized controlled trial (RCT) revealed an association between levosimendan use and a possible increased risk of bleeding postoperatively. Levosimendan's anti-platelet effects have been shown in in vitro studies. Current studies do not provide sufficient data to support a relation between perioperative levosimendan administration and increased bleeding risk.

PURPOSE

Our goal was to investigate the relation between perioperative levosimendan administration and increased bleeding risk using a meta-analysis study design.

METHODS

The PubMed, Ovid, EMBASE and Cochrane Library databases were searched for relevant RCTs before July 1, 2019. The outcome parameters included reoperation secondary to increased bleeding in the postoperative period, the amount of postoperative recorded blood loss, and the need for transfusion of packed red blood cells (RBCs) and other blood products.

RESULTS

A total of 1160 patients in nine RCTs (576 in the levosimendan group and 584 in the control group) were included according to our inclusion criteria. Analysis showed that perioperative levosimendan administration neither increased the rate of reoperation secondary to bleeding nor increased the amount of postoperative chest tube drainage when compared with the control group. In terms of blood product transfusion, levosimendan did not influence the requirement for RBC transfusion, platelet transfusion nor fresh frozen plasma (FFP) transfusion. Levosimendan also did not shorten or prolong the aortic cross-clamp time or the cardiopulmonary bypass time.

CONCLUSION

The analyzed parameters, including reoperations due to bleeding, postoperative chest drainage and the requirement for blood products, revealed that levosimendan did not increase postoperative bleeding risk. More studies with a larger sample size are needed to address a more reliable conclusion due to study limitations.

Current Practice of Calcium Use During Cardiopulmonary Bypass Weaning: Results of an International Survey

OBJECTIVES

To describe international practices on the use of calcium salts during cardiopulmonary bypass (CPB) weaning in adult cardiac surgery patients.

DESIGN

Multiple-choice survey on current practice of CPB weaning.

SETTING

Online survey using the SurveyMonkey platform.

PARTICIPANTS

Departments of cardiac anesthesiology worldwide.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Out of 112 surveys sent, 100 centers from 32 countries replied. The majority of centers (88 of 100 = 88%) administer calcium salts intraoperatively: 71 of 100 (71%) are using these drugs for CPB weaning and 78 of 100 (78%) for correction of hypocalcemia. Among the 88 centers that use calcium salts intraoperatively, 66% (58 of 88) of respondents use calcium chloride, 22% (19 of 88) use calcium gluconate, and 12% (11 of 88) use both drugs. Calcium salts are routinely used during normal (47 of 71 centers = 66%) and difficult (59 of 71 centers = 83%) weaning from CPB. Doses of 5 to 15 mg/kg during termination of CPB were used by 55 of 71 centers (77%) either by bolus (39 of 71, 55%) or over a time period longer than 1 minute (32 of 71 = 45%). Norepinephrine is the most commonly used first line vasopressor or inotropic agent used to support hemodynamics during termination of CPB in 32 out of 100 centers (32%), and calcium is the second one, used by 23 out of 100 centers (23%).

CONCLUSION

This survey demonstrates that the majority of cardiac centers use calcium in adult patients undergoing cardiac surgery, especially during weaning from CPB. There is variability on the type of drug, dose, and modality of drug administration.

Effects of levosimendan on ventriculo-arterial coupling and cardiac efficiency in paediatric patients with single-ventricle physiology after surgical palliation: retrospective study

OBJECTIVES

The use of levosimendan for paediatric patients with low cardiac output after congenital heart surgery has been recently described. We sought to evaluate ventriculo-arterial coupling (VAC) and other ventricular energetic parameters before and after 72 h from levosimendan start in infants with single-ventricle physiology and cardiac failure after palliation with Norwood or hybrid procedures.

METHODS

In this single-centre retrospective study, 9 consecutive patients affected by hypoplastic left heart syndrome-like anatomy were retrospectively analysed. Systolic elastance, diastolic elastance, arterial elastance, VAC and cardiac mechanical efficiency were calculated by measuring, through 2-dimensional echocardiography, end-systolic volume and end-diastolic volume and by recording mean arterial pressure and central venous pressure.

RESULTS

The median (range) weight and age were 2.8 (2.3–6) kg and 16.5 (6–116) days, respectively. After 72 h from levosimendan start, end-systolic volume significantly decreased (−1 ml, −3.2 to −0.1, P = 0.007), whereas mean arterial pressure and end-diastolic volume remained stable. Heart rate showed a significant decrease (−28 beats/min, −41 to 22, P = 0.008). Systolic elastance (2.9 mmHg/ml, 0.4–5.4, P = 0.008), arterial elastance (−5.9, −24 to −0.5, P = 0.038), VAC (−0.86, −1.5 to −0.16, P = 0.009) and cardiac mechanical efficiency (0.18, 0.03–0.22, P = 0.008) differences also showed significant modifications.

CONCLUSIONS

In a small case series of patients with single-ventricle physiology, levosimendan showed to improve contractility and optimize VAC, with a reduction of heart rate. Monitoring of VAC and ventricular energetics can be an interesting aspect to improve the management of heart failure in infants with univentricular anatomy.

Management of Acute Heart Failure during an Early Phase

Acute heart failure (AHF), a global pandemic with high morbidity and mortality, exerts a considerable economic burden. AHF includes a broad spectrum of clinical presentations ranging from new-onset heart failure to cardiogenic shock. Key elements of the management rely on the clinical diagnosis confirmed on, both, increased natriuretic peptides and echocardiography, and on the prompt initiation of oxygen therapy, including non-invasive positive pressure ventilation, vasodilators, and diuretics. A care pathway is essential, specifically when an acute coronary syndrome is suspected or in the case of cardiogenic shock. Association or increasing doses of vasopressors despite an adequate volume status are markers of progression toward a refractory cardiogenic shock state. For the latter, mechanical circulatory support should be initiated early, optimally before the onset of renal or liver failure. Thus, a tertiary care center is recommended for the management of patients with AHF who require percutaneous coronary intervention or mechanical circulatory support. This narrative review provides multidisciplinary guidance for the management of AHF and cardiogenic shock from pre-hospital to intensive care unit/cardiac care unit, based on contemporary evidence and expert opinion.

Prophylactic use of levosimendan in pediatric patients undergoing cardiac surgery: a prospective randomized controlled trial

BACKGROUND

The administration of levosimendan prophylactically to patients undergoing cardiac surgery remains a controversial practice, and few studies have specifically assessed the value of this approach in pediatric patients. This study therefore sought to explore the safety and efficacy of prophylactic levosimendan administration to pediatric patients as a means of preventing low cardiac output syndrome (LCOS) based upon hemodynamic, biomarker, and pharmacokinetic readouts.

METHODS

This was a single-center, double-blind, randomized, placebo-controlled trial. Patients ≤ 48 months old were enrolled between July 2018 and April 2019 and were randomly assigned to groups that received either placebo or levosimendan infusions for 48 h post-surgery, along with all other standard methods of care. LCOS incidence was the primary outcome of this study.

RESULTS

A total of 187 patients were enrolled, of whom 94 and 93 received levosimendan and placebo, respectively. LCOS incidence did not differ significantly between the levosimendan and placebo groups (10 [10.6%] versus 18 [19.4%] patients, respectively; 95% confidence interval [CI] 0.19-1.13; p = 0.090) nor did 90-day mortality (3 [3.2%] versus 4 [4.3%] patients, CI 0.14-3.69, p = 0.693), duration of mechanical ventilation (median, 47.5 h and 39.5 h, respectively; p = 0.532), ICU stay (median, 114.5 h and 118 h, respectively; p = 0.442), and hospital stay (median, 20 days and 20 days, respectively; p = 0.806). The incidence of hypotension and cardiac arrhythmia did not differ significantly between the groups. Levels of levosimendan fell rapidly without any plateau in plasma concentrations during infusion. A multiple logistic regression indicated that randomization to the levosimendan group was a predictor of LCOS.

CONCLUSIONS

Prophylactic levosimendan administration was safe in pediatric patients and had some benefit to postoperative hemodynamic parameters, but failed to provide significant benefit with respect to LCOS or 90-day mortality relative to placebo.

TRIAL REGISTRATION

Name of the registry: Safety evaluation and therapeutic effect of levosimendan on the low cardiac output syndrome in patients after cardiopulmonary bypass.

TRIAL REGISTRATION NUMBER

ChiCTR1800016594. Date of registration: 11 June 2018. URL of trial registry record: http://www.chictr.org.cn/index.aspx.

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

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

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

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

[Acute perioperative right heart insufficiency : Diagnostics and treatment]

Acute right heart failure is often overlooked as a cause of cardiopulmonary insufficiency. The various pathologies underlying right heart failure at the level of afterload, preload and contractility, make rapid, targeted diagnostics necessary. In addition to clinical symptoms and laboratory chemical parameters, echocardiography in particular is relevant for making a diagnosis. Symptomatic treatment of the endangered patient is essential. The focus is on a reduction of right ventricular pressure and afterload, a correction of systemic hypotension and positive inotropic support of the right ventricle. Mechanical organ replacement and support procedures are increasingly being used in the case of persistent right heart failure and expand the possibilities for treatment. Decisive for the prognosis is a causal treatment adapted to the underlying triggering disease.

Preservation of renal function in cardiac surgery patients with low cardiac output syndrome: levosimendan vs beta agonists

BACKGROUND

Some studies have been performed to assess the effects of levosimendan on cardiac function when administered to cardiac surgery patients with low cardiac output syndrome (LCOS) in the immediate postoperative period. Levosimendan is an inotropic agent for the treatment of low cardiac output syndrome that seems to have a protective effect on renal function.

METHODS

It is a quasi-experimental study. A total of 100 patients with LCOS received either beta-agonists or levosimendan. We assessed the incidence of postoperative kidney failure in cardiac surgery patients. In patients who had kidney failure at diagnosis of LCOS, we examined whether differences existed in the evolution of kidney failure based on the treatment administered for LCOS. The parameters measured included haemodynamics, oxygen supply, and renal function as assessed by the AKI scale. ANOVA, Student's t-test and Wilcoxon or Friedman tests were used.

RESULTS

Up to 30% of cardiac surgery patients had kidney failure at diagnosis of LCOS. Kidney failure at discharge from the ICU was more frequent in patients who received beta-agonist drugs as compared to those who received levosimendan (p < 0.05).

CONCLUSION

The incidence of kidney failure decreased with the postoperative administration of levosimendan to cardiac surgery patients with LCOS, as compared to beta-agonists.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN 46058317. Date of registration: 7/10/2019. Retrospectively registered.

[S3 guidelines on intensive medical care of cardiac surgery patients : Hemodynamic monitoring and cardiovascular system-an update]

An update of the S3- guidelines for treatment of cardiac surgery patients in the intensive care unit, hemodynamic monitoring and cardiovascular system was published by the Association of Scientific Medical Societies in Germany (AWMF) in January 2018. This publication updates the guidelines from 2006 and 2011. The guidelines include nine sections that in addition to different methods of hemodynamic monitoring also reviews the topic of volume therapy as well as vasoactive and inotropic drugs. Furthermore, the guidelines also define the goals for cardiovascular treatment. This article describes the most important innovations of these comprehensive guidelines.

Adrenergic Downregulation in Critical Care: Molecular Mechanisms and Therapeutic Evidence

Catecholamines remain the mainstay of therapy for acute cardiovascular dysfunction. However, adrenergic receptors quickly undergo desensitization and downregulation after prolonged stimulation. Moreover, prolonged exposure to high circulating catecholamines levels is associated with several adverse effects on different organ systems. Unfortunately, in critically ill patients, adrenergic downregulation translates into progressive reduction of cardiovascular response to exogenous catecholamine administration, leading to refractory shock. Accordingly, there has been a growing interest in recent years toward use of noncatecholaminergic inotropes and vasopressors. Several studies investigating a wide variety of catecholamine-sparing strategies (eg, levosimendan, vasopressin, β-blockers, steroids, and use of mechanical circulatory support) have been published recently. Use of these agents was associated with improvement in hemodynamics and decreased catecholamine use but without a clear beneficial effect on major clinical outcomes. Accordingly, additional research is needed to define the optimal management of catecholamine-resistant shock.

Prevention of Cardiac Surgery-Associated Acute Kidney Injury: A Review of Current Strategies

Acute kidney injury is a common and often severe postoperative complication after cardiac surgery, and is associated with poor short-term and long-term outcomes. Numerous randomized controlled trials have been conducted to investigate various strategies for prevention of cardiac surgery-associated acute kidney injury. Unfortunately, most trials that have been conducted to date have been negative. However, encouraging results have been demonstrated with preoperative administration of corticosteroids, leukocyte filtration, and administration of inhaled nitric oxide intraoperatively, and implementation of a Kidney Disease: Improving Global Outcomes bundle of care approach postoperatively. These findings require validation in large, multicenter trials.

Epinephrine, inodilator, or no inotrope in venoarterial extracorporeal membrane oxygenation implantation: a single-center experience

Background

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) can be a rescue therapy for patients in cardiogenic shock or in refractory cardiac arrest. After cannulation, vasoplegia and cardiac depression are frequent. In literature, there are conflicting data on inotropic therapy in these patients.

Methods

Analysis of a retrospective registry of all patients treated with VA-ECMO in a university hospital center between October 2010 and December 2018 for cardiogenic shock or extracorporeal cardiopulmonary resuscitation (eCPR) with a focus on individual early inotropic therapy.

Results

A total of 231 patients (age 58.6 ± 14.3, 29.9% female, 58% eCPR, in-house survival 43.7%) were analyzed. Of these, 41.6% received no inotrope therapy within the first 24 h (survival 47.9%), 29.0% received an inodilator (survival 52.2%), and 29.0% received epinephrine (survival 25.0%). Survival of patients with epinephrine was significantly worse compared to other patient groups when evaluating 30-day survival (p = 0.034/p = 0.005) and cumulative incidence of in-hospital death (p = 0.001). In a multivariate logistic regression analysis, treatment with epinephrine was associated with mortality in the whole cohort (OR 0.38, p = 0.011) as well as after propensity score matching (OR 0.24, p = 0.037). We found no significant differences between patients with inodilator treatment and those without.

Conclusion

Early epinephrine therapy within the first 24 h after cannulation for VA-ECMO was associated with poor survival compared to patients with or without any inodilator therapy. Until randomized data are available, epinephrine should be avoided in patients on VA-ECMO.

Hurdles to Cardioprotection in the Critically Ill

Cardiovascular disease is the largest contributor to worldwide mortality, and the deleterious impact of heart failure (HF) is projected to grow exponentially in the future. As heart transplantation (HTx) is the only effective treatment for end-stage HF, development of mechanical circulatory support (MCS) technology has unveiled additional therapeutic options for refractory cardiac disease. Unfortunately, despite both MCS and HTx being quintessential treatments for significant cardiac impairment, associated morbidity and mortality remain high. MCS technology continues to evolve, but is associated with numerous disturbances to cardiac function (e.g., oxidative damage, arrhythmias). Following MCS intervention, HTx is frequently the destination option for survival of critically ill cardiac patients. While effective, donor hearts are scarce, thus limiting HTx to few qualifying patients, and HTx remains correlated with substantial post-HTx complications. While MCS and HTx are vital to survival of critically ill cardiac patients, cardioprotective strategies to improve outcomes from these treatments are highly desirable. Accordingly, this review summarizes the current status of MCS and HTx in the clinic, and the associated cardiac complications inherent to these treatments. Furthermore, we detail current research being undertaken to improve cardiac outcomes following MCS/HTx, and important considerations for reducing the significant morbidity and mortality associated with these necessary treatment strategies.

2019 EACTS Expert Consensus on long-term mechanical circulatory support

Long-term mechanical circulatory support (LT-MCS) is an important treatment modality for patients with severe heart failure. Different devices are available, and many-sometimes contradictory-observations regarding patient selection, surgical techniques, perioperative management and follow-up have been published. With the growing expertise in this field, the European Association for Cardio-Thoracic Surgery (EACTS) recognized a need for a structured multidisciplinary consensus about the approach to patients with LT-MCS. However, the evidence published so far is insufficient to allow for generation of meaningful guidelines complying with EACTS requirements. Instead, the EACTS presents an expert opinion in the LT-MCS field. This expert opinion addresses patient evaluation and preoperative optimization as well as management of cardiac and non-cardiac comorbidities. Further, extensive operative implantation techniques are summarized and evaluated by leading experts, depending on both patient characteristics and device selection. The faculty recognized that postoperative management is multidisciplinary and includes aspects of intensive care unit stay, rehabilitation, ambulatory care, myocardial recovery and end-of-life care and mirrored this fact in this paper. Additionally, the opinions of experts on diagnosis and management of adverse events including bleeding, cerebrovascular accidents and device malfunction are presented. In this expert consensus, the evidence for the complete management from patient selection to end-of-life care is carefully reviewed with the aim of guiding clinicians in optimizing management of patients considered for or supported by an LT-MCS device.

Differences in Biomarkers Pattern Between Severe Isolated Right and Left Ventricular Dysfunction After Cardiac Surgery

OBJECTIVE

To find out if there are any differences in biomarkers between severe isolated right ventricular (RV) dysfunction and severe isolated left ventricular (LV) dysfunction after cardiac surgery using cardiopulmonary bypass.

DESIGN

Observational study.

SETTING

Teaching hospital.

PARTICIPANTS

A total of 46 patients who had severe isolated RV or LV dysfunction after cardiac surgery.

INTERVENTION

The authors collected perioperative clinical and biomarker data.

MEASUREMENTS AND MAIN RESULTS

Severe isolated RV dysfunction patients (n = 20) had higher postoperative direct bilirubin (p = 0.030), total bilirubin (p = 0.044), glucose (p = 0.011), and international normalized ratio (INR) (p = 0.050) by repeated measure analysis of variance when compared with patients with severe isolated LV dysfunction (n = 26). The RV group also showed lower preoperative alanine transferase (19.3 ± 1.5 v 32.7 ± 4.2, p = 0.001), higher 4-hour INR (1.5 ± 0.3 v 1.4 ± 0.2, p = 0.008), and higher 48-hour INR (1.8 ± 0.4 v 1.4 ± 0.1, p < 0.001). None in the LV group died, whereas 4 patients in the RV group died (all of them had preoperative atrial fibrillation and underwent double valve replacement surgery).

CONCLUSION

The authors observed biomarkers differences between severe isolated RV dysfunction and severe isolated RV dysfunction.

Management of cardiogenic shock complicating myocardial infarction: an update 2019

Cardiogenic shock (CS) remains the most common cause of death in patients admitted with acute myocardial infarction (AMI) and mortality remained nearly unchanged in the range of 40–50% during the last two decades. Early revascularization, vasopressors and inotropes, fluids, mechanical circulatory support, and general intensive care measures are widely used for CS management. However, there is only limited evidence for any of the above treatment strategies except for revascularization and the relative ineffectiveness of intra-aortic balloon pumping. This updated review will outline the management of CS complicating AMI with major focus on state-of-the art treatment.

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Protocol of a randomised controlled trial in cardiac surgical patients with endothelial dysfunction aimed to prevent postoperative acute kidney injury by administering nitric oxide gas

INTRODUCTION

Postoperative acute kidney injury (AKI) is a common complication in cardiac surgery. Levels of intravascular haemolysis are strongly associated with postoperative AKI and with prolonged (>90 min) use of cardiopulmonary bypass (CPB). Ferrous plasma haemoglobin released into the circulation acts as a scavenger of nitric oxide (NO) produced by endothelial cells. Consequently, the vascular bioavailability of NO is reduced, leading to vasoconstriction and impaired renal function. In patients with cardiovascular risk factors, the endothelium is dysfunctional and cannot replenish the NO deficit. A previous clinical study in young cardiac surgical patients with rheumatic fever, without evidence of endothelial dysfunction, showed that supplementation of NO gas decreases AKI by converting ferrous plasma haemoglobin to ferric methaemoglobin, thus preserving vascular NO. In this current trial, we hypothesised that 24 hours administration of NO gas will reduce AKI following CPB in patients with endothelial dysfunction.

METHODS

This is a single-centre, randomised (1:1) controlled, parallel-arm superiority trial that includes patients with endothelial dysfunction, stable kidney function and who are undergoing cardiac surgery procedures with an expected CPB duration >90 min. After randomisation, 80 parts per million (ppm) NO (intervention group) or 80 ppm nitrogen (N2, control group) are added to the gas mixture. Test gases (N2 or NO) are delivered during CPB and for 24 hours after surgery. The primary study outcome is the occurrence of AKI among study groups. Key secondary outcomes include AKI severity, occurrence of renal replacement therapy, major adverse kidney events at 6 weeks after surgery and mortality. We are recruiting 250 patients, allowing detection of a 35% AKI relative risk reduction, assuming a two-sided error of 0.05.

ETHICS AND DISSEMINATION

The Partners Human Research Committee approved this trial. Recruitment began in February 2017. Dissemination plans include presentations at scientific conferences, scientific publications and advertising flyers and posters at Massachusetts General Hospital.

TRIAL REGISTRATION NUMBER

NCT02836899.

Acute kidney injury after cardiac surgery: prevalence, impact and management challenges

Acute kidney injury (AKI) is a major medical problem that is of particular concern after cardiac surgery. Perioperative AKI is independently associated with an increase in short-term morbidity, costs of treatment, and long-term mortality. In this review, we explore the definition of cardiac surgery-associated acute kidney injury (CSA-AKI) and identify diverse mechanisms and risk factors contributing to the renal insult. Current theories of the pathophysiology of CSA-AKI and description of its clinical course will be addressed in this review. Data on the most promising renal protective strategies in cardiac surgery, from well-designed studies, will be scrutinized. Furthermore, diagnostic tools such as novel biomarkers of AKI and their potential utility will be discussed.

Levosimendan in patients with reduced left ventricular function undergoing isolated coronary or valve surgery

OBJECTIVE

In the Levosimendan in Patients with Left Ventricular Systolic Dysfunction Undergoing Cardiac Surgery Requiring Cardiopulmonary Bypass (LEVO-CTS) trial, no differences in clinical outcomes were observed between levosimendan and placebo in a broad population of patients undergoing cardiac surgery. In previous studies, the benefits of levosimendan were most clearly evident in patients undergoing isolated coronary artery bypass grafting (CABG) surgery. In a prespecified analysis of LEVO-CTS, we compared treatment-related outcomes and costs across types of cardiac surgical procedures.

METHODS

Overall, 563 (66.4%) patients underwent isolated CABG, 97 (11.4%) isolated valve, and 188 (22.2%) combined CABG/valve surgery. Outcomes included the co-primary 4-component composite (30-day mortality, 30-day renal replacement, 5-day myocardial infarction, or 5-day mechanical circulatory support), the 2-component composite (30-day mortality or 5-day mechanical circulatory support), 90-day mortality, low cardiac output syndrome (LCOS), and 30-day medical costs.

RESULTS

The 4- and 2-component outcomes were not significantly different with levosimendan and placebo in patients undergoing CABG (15.2% vs 19.3% and 7.8% vs 10.4%), valve (49.0% vs 33.3% and 22.4% vs 2.1%), or combined procedures (39.6% vs 35.9% and 24.0% vs 19.6%). Ninety-day mortality was lower with levosimendan in isolated CABG (2.1% vs 7.9%; hazard ratio [HR], 0.26; 95% confidence interval [CI], 0.11-0.64), but not significantly different in valve (8.3% vs 2.0%; HR, 4.10; 95% CI, 0.46-36.72) or combined procedures (10.4% vs 7.6%; HR, 1.39; 95% CI, 0.53-3.64; interaction P = .011). LCOS (12.0% vs 22.1%; odds ratio, 0.48; 95% CI, 0.30-0.76; interaction P = .118) was significantly lower in levosimendan-treated patients undergoing isolated CABG. Excluding study drug costs, median and mean 30-day costs were $53,707 and $65,852 for levosimendan and $54,636 and $67,122 for placebo, with a 30-day mean difference (levosimendan - placebo) of -$1270 (bootstrap 95% CI, -$8722 to $6165).

CONCLUSIONS

Levosimendan was associated with lower 90-day mortality and LCOS in patients undergoing isolated CABG, but not in those undergoing isolated valve or combined CABG/valve procedures.

Calcium Administration During Weaning From Cardiopulmonary Bypass: A Narrative Literature Review

The search for safe and effective patient management strategies during weaning from cardiopulmonary bypass is ongoing; intravenous calcium is occasionally used as a first-line drug. The physiologic role of calcium suggests that it can support the function of the cardiovascular system during this critical period. Patients may be mildly hypocalcemic after cardiopulmonary bypass; however, this degree of hypocalcemia does not significantly impair the cardiovascular system. The transient beneficial effects of calcium administration (increase in arterial blood pressure, systemic vascular resistance, cardiac index, stroke volume, and coronary perfusion pressure) might be helpful in cases of moderate contractility reduction or vasoplegia. Nonetheless, effects on clinically relevant endpoints are unknown, and possible systemic side effects, such as transient reduction in internal mammary artery graft flow, attenuation of the effects of β-sympathomimetics, "stone heart" phenomenon, and pancreatic cellular injury, may limit the use of calcium salts. Further studies are needed to expand the understanding of the effects of calcium administration on patient outcomes.

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.

The efficacy and safety of prophylactic use of levosimendan on patients undergoing coronary artery bypass graft: a systematic review and meta-analysis

Prophylactic use of levosimendan in cardiac surgery remains controversial and no meta-analysis has been done exclusively about that in patients undergoing coronary artery bypass graft (CABG) surgery. We conducted this systematic review and meta-analysis of levosimendan in CABG using PubMed, Embase, Scopus, and Cochrane Library (till April 20, 2018). Two-hundred and forty manuscripts were identified and 21 randomized trials (1727 patients in total) investigating the effect of levosimendan on the patients undergoing CABG surgery were finally included in this analysis. We found that levosimendan was an effective, well-tolerated inotropic agent in CABG, which was associated with a significantly reduced mortality rate [odds ratio (OR) 0.43, 95% confidence interval (CI) (0.26, 0.71), p = 0.001, I² = 0%] and postoperative atrial fibrillation [OR 0.50, 95% CI (0.26, 0.97), p = 0.04, I² = 76%], but a higher incidence of hypotension [OR 2.26, 95% CI (1.05, 4.85), p = 0.04, I² = 79%]. Subgroup analyses revealed that such a benefit was mainly observed in the isolated CABG, the preoperative administration, with-bolus and on-pump subgroups. More high-quality and well-designed prospective studies are needed to confirm or disprove our findings in future.

Levosimendan as rescue therapy in low output syndrome after cardiac surgery: effects and predictors of outcome

Objectives

Calcium sensitizers have been shown to improve outcomes in patients with low cardiac output syndrome (LCOS) after cardiac surgery. We assessed the effects of levosimendan on LCOS in cardiac surgical patients to identify outcome predictors.

Methods

A total of 106 patients in whom LCOS persisted despite conventional therapy additionally received 0.1 µg/kg/min of levosimendan for 24 hours according to a defined treatment algorithm. Baseline and treatment data as well as hemodynamic and outcome parameters were compared between survivors and nonsurvivors, and a multivariate correlation and regression tree analysis was implemented.

Results

The ejection fraction significantly increased from 27% ± 4% to 38% ± 8% within 24 hours and to 45% ± 10% within 48 hours of starting levosimendan. These changes were accompanied by a significant increase in cardiac output from 5.2 ± 0.6 to 6.2 ± 0.7 L/min within 24 hours and significant dose reductions in vasopressors and inotropes. In contrast to nonsurvivors, survivors’ need for inotropic support decreased after the addition of levosimendan to the therapy.

Conclusion

In our patients, all of whom were treated according to the same algorithm, the response to levosimendan in terms of the post-levosimendan need for inotropes and vasopressors predicted survival.

Impact of levosimendan on weaning from peripheral venoarterial extracorporeal membrane oxygenation in intensive care unit

BACKGROUND

Few data are available on the impact of levosimendan in refractory cardiogenic shock patients undergoing peripheral venoarterial extracorporeal membrane oxygenation (VA-ECMO). The aim of this study was to evaluate the impact of levosimendan on VA-ECMO weaning in patients hospitalized in intensive care unit (ICU).

METHODS

This retrospective cohort study was conducted in a French university hospital from 2010 to 2017. All patients hospitalized in ICU undergoing VA-ECMO were consecutively evaluated.

RESULTS

A total of 150 patients undergoing VA-ECMO were eligible for the study. Thirty-eight propensity-matched patients were evaluated in the levosimendan group and 65 in the non-levosimendan group. In patients treated with levosimendan, left ventricular ejection fraction had increased from 21.5 ± 9.1% to 30.7 ± 13.5% (P < 0.0001) and aortic velocity-time integral from 8.9 ± 4 cm to 12.5 ± 3.8 cm (P = 0.002) 24 h after drug infusion. After propensity score matching, levosimendan was the only factor associated with a significant reduction in VA-ECMO weaning failure rates (hazard ratio = 0.16; 95% confidence interval 0.04-0.7; P = 0.01). Kaplan-Meier survival curves showed that survival rates at 30 days were 78.4% for the levosimendan group and 49.5% for the non-levosimendan group (P = 0.02). After propensity score matching analysis, the difference in 30-day mortality between the two groups was not significant (hazard ratio = 0.55; 95% confidence interval 0.27-1.10; P = 0.09).

CONCLUSIONS

Our results suggest that levosimendan was associated with a beneficial effect on VA-ECMO weaning in ICU patients.

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.

Levosimendan is superior to epinephrine on coronary flow for lipid-base resuscitation of bupivacaine-induced asystole in the isolated rat heart

Background

Successful resuscitation from asystole induced by bupivacaine requires the reestablishment of a sufficient coronary flow (CF) quickly. This study was designed to test whether levosimendan was superior to epinephrine in the reestablishment of crucial coronary flows after bupivacaine-induced asystole.

Methods

The isolated, perfused, nonrecirculating, Langendorff rat heart preparation was used. Bupivacaine 100 μmol/L was perfused into rat hearts to induce asystole, and then for 3 min thereafter. Three experimental groups were assessed after asystole with infusions as follow: (1) a mixture of 2% lipid emulsion and 40 μmol/L bupivacaine (control group), (2) a mixture of 0.15 μg/mL epinephrine combined with 2% lipid emulsion and 40 μmol/L bupivacaine (epinephrine group), and (3) a mixture of 5 μmol/L levosimendan combined with a 2% lipid emulsion and 40 μmol/L bupivacaine mixture (levosimendan group). Coronary flow (CF), the time to recovery (T_recovery), the number of ventricular arrhythmias, and cardiac function parameters were recorded for 40 min after heartbeat recovery.

Results

All hearts in the control, epinephrine and levosimendan groups had heartbeat recovery. The rank order of the mean CF from highest to lowest was the levosimendan group > the epinepgrine group > the control group (P < 0.05). The rank order of T_recovery from shortest to longest was the levosimendan group < the epinephrine group < the control group (P < 0.01). During the recovery phase, isolated rat hearts developed more ventricular arrhythmias in the epinephrine group than in the levosimendan group (P = 0.01).

Conclusion

Levosimendan is superior to epinephrine in producing higher CFs and faster recovery when reversing bupivacaine-induced asystole in the isolated rat hearts.