The Effect of Levosimendan Versus Milrinone on the Occurrence Rate of Acute Kidney Injury Following Congenital Heart Surgery in Infants: A Randomized Clinical Trial

High-sensitive troponinT, interleukin-8, and interleukin-6 link with post-surgery risk in infant heart surgery

BACKGROUND

This study focuses on biomarkers in infants after open heart surgery, and examines the association of high-sensitive troponin T (hs-cTnT), interleukin-6 (IL-6), and interleukin-8 (IL-8) with postoperative acute kidney injury (AKI), ventilatory support time and need of vasoactive drugs.

METHODS

Secondary exploratory study from a double-blinded clinical randomized trial (Mile-1) on 70 infants undergoing open heart surgery with cardiopulmonary bypass (CPB). In this sub-study, the entire study population was examined without considering the study drugs. The biomarkers' peak concentration (highest concentration at 2 or 6 h post-CPB) were used for statistical analyses.

RESULTS

Peak IL-8, hs-cTnT, and IL-6 occurred at 2 h post-CPB for 96%, 79%, and 63% of the patients, respectively. The odds ratio of developing AKI2-3 for IL-6 > 293 pg/mL was 23.4 (95% CI 5.3;104.0), for IL-8 > 100 pg/mL it was 11.5 (3.0;44.2), and for hs-cTnT >5597 pg/mL it was 6.1 (1.5; 24.5). In more than two third of the patients with the highest peak concentrations of IL-8, IL-6, and hs-cTnT, there was a need for ventilatory support for >24 h and use of vasoactive drugs at 24 h post-CPB, while in less than one third of the patients with the lowest peak concentrations of IL-8 and hs-cTnT such requirements were observed.

CONCLUSIONS

The peak biomarker concentrations and CPB-time strongly predicted AKI2-3, with IL-6 and IL-8 emerging as strongest predictors. Furthermore, our findings suggest that measuring hs-cTnT and IL-8 just 2 h post-CPB-weaning may assist in identifying infants suitable for early extubation and highlight those at risk of prolonged ventilation.

Comparison of Levosimendan Versus Milrinone After the Arterial Switch Operation for Infants ≤3 kg

Background: Various inotropes and inodilators have been utilized to treat low cardiac output syndrome after the arterial switch operation. The use of levosimendan, a calcium sensitizer has been limited in this setting. This study compares the effects of levosimendan with milrinone in managing low cardiac output after the arterial switch operation. Methods: A retrospective, comparative study was conducted in a tertiary care hospital on patients weighing up to 3 kg undergoing the arterial switch operation between January 2017 and January 2022. Patients received a loading dose followed by continuous infusion of either levosimendan or milrinone. Echocardiographic, hemodynamic and biochemical parameters were compared. Results: Forty-three patients received levosimendan and 42 patients received milrinone as the primary test drug. Cardiac index of less than 2.2 L/min/m2 on postoperative day 1 and 2 was found in 9.3% and 2.3% of patients receiving levosimendan versus 26.2% and 11.9% in those receiving milrinone, respectively (P = .04 and .08, respectively). Early lactate-clearance and better central venous oxygen saturations were noted in the levosimendan group. Prevalence of acute kidney injury was higher in the milrinone group (50% vs 28%; P = .03). Use of peritoneal dialysis in the milrinone group versus levosimendan was 31% and 16.3%, respectively (P = .11). There was no difference in hospital mortality between the groups (milrinone, 3; levosimendan, 2, P = .62). Conclusions: Levosimendan is safe and as effective as milrinone to treat low cardiac output syndrome occurring in neonates after the arterial switch operation. In addition we found that levosimendan was renal protective when compared with milrinone.

Reassessing the role of milrinone in the treatment of heart failure and pulmonary hypertension in neonates and children: a systematic review and meta-analysis

To evaluate milrinone's impact on pediatric cardiac function, focusing on its specific role as an inotrope and lusitrope, while considering its systemic and pulmonary vasodilatory effects. Search of PubMed, EMBASE, and the Cochrane Library up to August 2023. We included all studies that evaluated milrinone in children under 18 years old in neonatal, pediatric, or cardiac intensive care units. We excluded case reports, studies that did not provide tabular information on milrinone's outcomes, and studies focused on non-intensive care populations. We extracted data on the research design, objectives, study sample, and results of each study, including the impact of milrinone and any associated factors. We screened a total of 9423 abstracts and 41 studies were ultimately included. Milrinone significantly improved left ventricular ejection fraction (WMD 3.41 [95% CI 0.61 - 6.21]), left ventricle shortening fraction (WMD 4.25 [95% CI 3.43 - 5.08]), cardiac index (WMD 0.50 [95% CI 0.32 to 0.68]), left ventricle output (WMD 55.81 [95% CI 4.91 to 106.72]), serum lactate (WMD -0.59 [95% CI -1.15 to -0.02]), and stroke volume index (WMD 2.95 [95% CI 0.09 - 5.82]). However, milrinone was not associated with improvements in ventricular myocardial performance index (WMD -0.01 [95% CI -0.06 to 0.04]) and ventricular longitudinal strain (WMD -2.14 [95% CI -4.56 to 0.28]). Furthermore, milrinone was not associated with isovolumetric relaxation time reduction (WMD -8.87 [95% CI -21.40 to 3.66]).

CONCLUSION

Our meta-analysis suggests potential clinical benefits of milrinone by improving cardiac function, likely driven by its systemic vasodilatory effects. However, questions arise about its inotropic influence and the presence of a lusitropic effect. Moreover, milrinone's pulmonary vasodilatory effect appears relatively weaker compared to its systemic actions. Further research is needed to elucidate milrinone's precise mechanisms and refine its clinical applications in pediatric practice.

WHAT IS KNOWN

• Milrinone is a phosphodiesterase III inhibitor that has been used to treat a variety of pediatric and neonatal conditions. • Milrinone is believed to exert its therapeutic effects by enhancing cardiac contractility and promoting vascular relaxation.

WHAT IS NEW

• Milrinone may not have a significant inotropic effect. • Milrinone's pulmonary vasodilatory effect is less robust than its systemic vasodilatory effect.

Drugs in treating paediatric acute kidney injury

Acute kidney injury (AKI) is a complex syndrome which affects a significant proportion of hospitalized children. The breadth and impact of AKI on health outcomes in both adults and children have come to the fore in recent years with increasing awareness encouraging research advancement. Despite this, management strategies for most types of AKI remain heavily reliant on fluid and electrolyte management, hemodynamic optimization, nephrotoxin avoidance and appropriate initiation of kidney replacement therapy. Specific drugs targeting the mechanisms involved in AKI remain elusive. Recent improvement in appreciation of the complexity of AKI pathophysiology has allowed for greater opportunity to consider novel therapeutic agents. A number of drugs specifically targeting AKI are in various stages of development. This review will consider some novel and repurposed agents; interrogate the plausibility of the proposed mechanisms of action, as they relate to what we know about the pathophysiology of AKI; and review the level of existing literature supporting their efficacy. The evidence base, particularly in children, is limited.

Milrinone for the treatment of heart failure caused by severe Pneumonia in children with congenital heart disease: a meta-analysis

BACKGROUND

Children with congenital heart disease (CHD) are easily complicated by severe pneumonia and heart failure. We aimed to conduct a meta-analysis to evaluate the effects and safety of milrinone for the treatment of heart failure caused by severe pneumonia in children with CHD to provide evidence for the clinical CHD treatment.

METHODS

Two authors searched MEDLINE, PubMed, Embase, Science Direct, Cochrane Central Register of Controlled Trials, the Cochrane Library, Wanfang database, Chinese Biomedical Literature Database, China National Knowledge Infrastructure (CNKI) for randomized controlled trials (RCTs) about the application of milrinone in the treatment of heart failure caused by severe pneumonia in children with CHD in children up to December 10, 2022. Two evaluators independently selected the literature, extracted data and evaluated the methodological quality, meta-analysis was carried out with RevMan 5.3 software.

RESULTS

Eight RCTs involving 680 CHD children complicated by severe pneumonia and heart failure were included in this meta-analysis. Meta-analysis indicated that total effective rate of the milrinone group was higher than that of control group (RR = 1.25, 95%CI: 1.17 ~ 1.34, P < 0.001), the time to stable heart rate of the milrinone group was less than that of control group (RR=-0.88, 95%CI: -1.09~ -0.67, P < 0.001). The time to stable respiration of the milrinone group was less than that of control group (RR=-0.98, 95%CI: -1.17~ -0.78, P < 0.001). The LVEF of the milrinone group was higher than that of control group (RR = 6.46, 95%CI: 5.30 ~ 7.62, P < 0.001). There was no significant difference in the incidence of adverse reactions between the milrinone group and control group (RR = 0.85, 95%CI: 0.47 ~ 1.56, P = 0.061). Funnel plots and Egger regression test results indicated that there were no statistical publication bias amongst the synthesized outcomes (all P > 0.05).

CONCLUSIONS

Milrinone is beneficial to improve clinical symptoms and cardiac function and increase the therapeutic effect and safety in children with CHD complicated by severe pneumonia and heart failure. However, more RCTs with large samples and rigorous design are needed to verify this finding.

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

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

Strategies to Prevent Acute Kidney Injury after Pediatric Cardiac Surgery: A Network Meta-Analysis

BACKGROUND AND OBJECTIVES

AKI is a common complication after pediatric cardiac surgery and has been associated with higher morbidity and mortality. We aimed to compare the efficacy of available pharmacologic and nonpharmacologic strategies to prevent AKI after pediatric cardiac surgery.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

PubMed/MEDLINE, Embase, Cochrane Controlled Trials Register, and reference lists of relevant articles were searched for randomized controlled trials from inception until August 2020. Random effects traditional pairwise, Bayesian network meta-analyses, and trial sequential analyses were performed.

RESULTS

Twenty randomized controlled trials including 2339 patients and 11 preventive strategies met the eligibility criteria. No overall significant differences were observed compared with control for corticosteroids, fenoldopam, hydroxyethyl starch, or remote ischemic preconditioning in traditional pairwise meta-analysis. In contrast, trial sequential analysis suggested a 80% relative risk reduction with dexmedetomidine and evidence of <57% relative risk reduction with remote ischemic preconditioning. Nonetheless, the network meta-analysis was unable to demonstrate any significant differences among the examined treatments, including also acetaminophen, aminophylline, levosimendan, milrinone, and normothermic cardiopulmonary bypass. Surface under the cumulative ranking curve probabilities showed that milrinone (76%) was most likely to result in the lowest risk of AKI, followed by dexmedetomidine (70%), levosimendan (70%), aminophylline (59%), normothermic cardiopulmonary bypass (57%), and remote ischemic preconditioning (55%), although all showing important overlap.

CONCLUSIONS

Current evidence from randomized controlled trials does not support the efficacy of most strategies to prevent AKI in the pediatric population, apart from limited evidence for dexmedetomidine and remote ischemic preconditioning.

Levosimendan in rats decreases acute kidney injury after cardiopulmonary resuscitation by improving mitochondrial dysfunction

Background

Acute kidney injury (AKI), the most common complication after cardiac resuscitation, is highly prevalent and harmful. There is increasing evidence that levosimendan can improve cardiac output, increase renal blood flow, and prevent AKI. As a novel calcium sensitizer, levosimendan may exert its protective effect via mitochondria.

Methods

Rat models of asphyxia-induced cardiac arrest and cardiopulmonary resuscitation (CPR) were set up. Thirty healthy adult male SD rats were randomly divided into CPR group (CPR group, n=10), levosimendan-treated group (levo group, n=10), and sham-operated group (sham group, n=10). Twelve hours after CPR, serum renal function indicators were measured, the kidney injury and mitochondrial morphological changes were observed. Oxygen uptake of the mitochondria, mitochondrial adenosine triphosphate (ATP) and mitochondrial free Ca²⁺ concentration were measured. Oxidative stress-related indicator levels in rat kidney tissues were further detected to analyze the differences in apoptosis rates among these three groups. Mitochondrial optic atrophy 1 (Opa1), dynamin-related protein 1 (Drp1), and apoptosis-related proteins were detected using Western blotting.

Results

Compared with the sham group, the CPR group had a significant increase in renal tissue damage. PAS staining and HE stains confirmed that CPR led to renal histopathological damage and destruction of the mitochondrial structure. Levosimendan improved the histopathological and ultrastructural damages of kidneys. Further analysis revealed that mitochondrial ATP content, NADH dehydrogenase, succinate dehydrogenase/cytochrome C oxidase, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (CSH-Px) decreased. Free Ca²⁺ concentration and malondialdehyde (MDA) significantly increased (all P<0.05) in the kidney tissues of rats in the CPR group. However, mitochondrial ATP content, NADH dehydrogenase, succinate dehydrogenase/cytochrome C oxidase, SOD, CAT, and CSH-Px increased, whereas free Ca²⁺ concentration and MDA decreased (all P<0.05) in the levo group. The apoptosis rate increased in the CPR group. There were significantly increased levels of Drp1 protein levels, and significantly decreased Opa1 expression (all P<0.05). However, the levo group showed the opposite effects (all P<0.05).

Conclusions

Levosimendan can alleviate AKI following CPR, which may be achieved by improving mitochondrial dysfunction and suppressing the mitochondrial apoptosis pathway.

Levosimendan Versus Milrinone and Release of Myocardial Biomarkers After Pediatric Cardiac Surgery: Post Hoc Analysis of Clinical Trial Data

OBJECTIVES

We compared the effect of two inodilators, levosimendan and milrinone, on the plasma levels of myocardial injury biomarkers, that is, high-sensitivity troponin T and heart-type fatty acid binding protein, and on N-terminal prohormone of brain natriuretic peptide as a biomarker of ventricular function. We hypothesized that levosimendan could attenuate the degree of myocardial injury when compared with milrinone.

DESIGN

A post hoc, nonprespecified exploratory secondary analysis of the Milrinone versus Levosimendan-1 trial (ClinicalTrials.gov Identifier: NCT02232399).

SETTING

Two pediatric tertiary university hospitals.

PATIENTS

Infants 1-12 months old, diagnosed with ventricular septal defect, complete atrioventricular septal defect, or Tetralogy of Fallot undergoing corrective surgery with cardiopulmonary bypass.

INTERVENTIONS

Seventy patients received a loading dose of either levosimendan or milrinone at the start of cardiopulmonary bypass followed by an infusion of the respective drug, which continued for 26 hours.

MEASUREMENTS AND MAIN RESULTS

Plasma levels of the three cardiac biomarkers were measured prior to the initiation of cardiopulmonary bypass and 2, 6, and 24 hours after weaning from cardiopulmonary bypass. In both groups, the levels of high-sensitivity troponin T and heart-type fatty acid binding protein were highest at 2 hours post cardiopulmonary bypass, whereas the highest level of N-terminal prohormone of brain natriuretic peptide occurred at 24 hours post cardiopulmonary bypass. There was no significant difference in the biomarkers' plasma levels between the study groups over time. Neither was there a significant difference in the postoperative peak plasma levels of the cardiac biomarkers.

CONCLUSIONS

In this post hoc analysis of the MiLe-1 trial, there was no demonstrable difference in the postoperative cardiac biomarker profile of myocardial injury and ventricular function when comparing infants managed in the perioperative period with levosimendan versus milrinone.

A systematic review of the evidence supporting post-operative medication use in congenital heart disease

BACKGROUND

Targeted drug development efforts in patients with CHD are needed to standardise care, improve outcomes, and limit adverse events in the post-operative period. To identify major gaps in knowledge that can be addressed by drug development efforts and provide a rationale for current clinical practice, this review evaluates the evidence behind the most common medication classes used in the post-operative care of children with CHD undergoing cardiac surgery with cardiopulmonary bypass.

METHODS

We systematically searched PubMed and EMBASE from 2000 to 2019 using a controlled vocabulary and keywords related to diuretics, vasoactives, sedatives, analgesics, pulmonary vasodilators, coagulation system medications, antiarrhythmics, steroids, and other endocrine drugs. We included studies of drugs given post-operatively to children with CHD undergoing repair or palliation with cardiopulmonary bypass.

RESULTS

We identified a total of 127 studies with 51,573 total children across medication classes. Most studies were retrospective cohorts at single centres. There is significant age- and disease-related variability in drug disposition, efficacy, and safety.

CONCLUSION

In this study, we discovered major gaps in knowledge for each medication class and identified areas for future research. Advances in data collection through electronic health records, novel trial methods, and collaboration can aid drug development efforts in standardising care, improving outcomes, and limiting adverse events in the post-operative period.

Cardiorenal Syndrome

Cardiorenal syndrome (CRS) describes a specific acute and chronic clinical picture in which the heart or the kidney are primarily dysfunctioning and secondarily affect each other. CRS is divided into five classes: acute and chronic CRS, acute and chronic renocardiac syndromes, and secondary dysfunction of heart and kidneys. This article specifically details the classification and the epidemiology, some risk factors, and the pathophysiology of CRS. Some emerging aspects of CRS are also discussed, such as CRS in patients with end-stage heart failure, with mechanical ventricular assistance, and after heart transplantation. Finally, some aspects of pediatric CRS are detailed.

An evidence-based review of the use of vasoactive and inotropic medications in post-operative paediatric patients after cardiac surgery with cardiopulmonary bypass from 2000 to 2020

BACKGROUND

Infants with moderate-to-severe CHD frequently undergo cardiopulmonary bypass surgery in childhood. Morbidity and mortality are highest in those who develop post-operative low cardiac output syndrome. Vasoactive and inotropic medications are mainstays of treatment for these children, despite limited evidence supporting their use.

METHODS

To help inform clinical practice, as well as the conduct of future trials, we performed a systematic review of existing literature on inotropes and vasoactives in children after cardiac surgery using the PubMed and EMBASE databases. We included studies from 2000 to 2020, and the patient population was defined as birth - 18 years of age. Two reviewers independently reviewed studies to determine final eligibility.

RESULTS

The final analysis included 37 papers. Collectively, selected studies reported on 12 different vasoactive and inotropic medications in 2856 children. Overall evidence supporting the use of these drugs in children after cardiopulmonary bypass was limited. The majority of studies were small with 30/37 (81%) enrolling less than 100 patients, 29/37 (78%) were not randomised, and safety and efficacy endpoints differed widely, limiting the ability to combine data for meta-analyses.

CONCLUSION

Vasoactive and inotropic support remain critical parts of post-operative care for children after cardiopulmonary bypass surgery. There is a paucity of data for the selection and dosing of vasoactives and inotropes for these patients. Despite the knowledge gaps that remain, numerous recent innovations create opportunities to rethink the conduct of clinical trials in this high-risk population.