Risk factors for systemic inflammatory response after congenital cardiac surgery

Promising results of a clinical feasibility study: CIRBP as a potential biomarker in pediatric cardiac surgery

Objective

Cold-inducible RNA binding Protein (CIRBP) has been shown to be a potent inflammatory mediator and could serve as a novel biomarker for inflammation. Systemic inflammatory response syndrome (SIRS) and capillary leak syndrome (CLS) are frequent complications after pediatric cardiac surgery increasing morbidity, therefore early diagnosis and therapy is crucial. As CIRBP serum levels have not been analyzed in a pediatric population, we conducted a clinical feasibility establishing a customized magnetic bead panel analyzing CIRBP in pediatric patients undergoing cardiac surgery.

Methods

A prospective hypothesis generating observational clinical study was conducted at the German Heart Center Berlin during a period of 9 months starting in May 2020 (DRKS00020885, https://drks.de/search/de/trial/DRKS00020885). Serum samples were obtained before the cardiac operation, upon arrival at the pediatric intensive care unit, 6 and 24 h after the operation in patients up to 18 years of age with congenital heart disease (CHD). Customized multiplex magnetic bead-based immunoassay panels were developed to analyze CIRBP, Interleukin-1β (IL-1β), Interleukin-6 (IL-6), Interleukin-8 (IL-8), Interleukin-10 (IL-10), Monocyte chemotactic protein 1 (MCP-1), Syndecan-1 (SDC-1), Thrombomodulin (TM), Vascular endothelial growth factor (VEGF-A), Angiopoietin-2 (Ang-2), and Fibroblast growth factor 23 (FGF-23) in 25 µl serum using the Luminex MagPix® system.

Results

19 patients representing a broad range of CHD (10 male patients, median age 2 years, 9 female patients, median age 3 years) were included in the feasibility study. CIRBP was detectable in the whole patient cohort. Relative to individual baseline values, CIRBP concentrations increased 6 h after operation and returned to baseline levels over time. IL-6, IL-8, IL-10, and MCP-1 concentrations were significantly increased after operation and except for MCP-1 concentrations stayed upregulated over time. SDC-1, TM, Ang-2, as well as FGF-23 concentrations were also significantly increased, whereas VEGF-A concentration was significantly decreased after surgery.

Discussion

Using customized magnetic bead panels, we were able to detect CIRBP in a minimal serum volume (25 µl) in all enrolled patients. To our knowledge this is the first clinical study to assess CIRBP serum concentrations in a pediatric population.

Refraining from Packed Red Blood Cells in Cardiopulmonary Bypass Priming as a Method of Neuroprotection in Pediatric Cardiac Surgery

Congenital heart defect (CHD) surgeries are performed with cardiopulmonary bypass (CPB) and are complicated by several factors that affect the child's brain. However, to date, the number of studies on brain protection in cardiac surgery remains small. The aim of this study was to assess the impact of refraining from using packed red blood cells (PRBCs) in priming solutions in children with congenital defects (CHDs) who require surgical interventions using CPB to prevent brain injury in the postoperative period.

MATERIAL AND METHODS

This study included 40 children, and the mean age was 14 (12-22.5) months and the mean weight was 8.8 (7.25-11) kg. All patients underwent CHD closure using CPB. The patients were divided into two groups depending on the use of PRBCs in the priming solution. Brain injury was assessed using three specific blood serum markers, namely S100 calcium-binding protein β (S100β), neuron-specific enolase (NSE) and glial fibrillary acidic protein (GFAP) before surgery, after the completion of CPB and 16 h after surgery (first, second and third control points). Markers of systemic inflammatory response were also analyzed, including interleukin-1, -6, -10 and tumor necrosis factor alpha (TNF-α). A clinical assessment of brain injury was carried out using a valid, rapid, observational tool for screening delirium in children of this age group, i.e., "Cornell Assessment of Pediatric Delirium".

RESULTS

Factors of the intra- and postoperative period were analyzed, such as hemoglobin levels, oxygen delivery (cerebral tissue oxygenation, blood lactate level and venous oxygen saturation) and indicators of organ dysfunction (creatinine, urea, bilirubin levels, duration of CPB and length of stay in the ICU). Following the procedure, there were no significant differences between the groups and all indicators were within the reference values, thus demonstrating the safety of CHD closure without transfusion. Moreover, the highest level of specific markers of brain injury were noted immediately after the completion of CPB in both groups. The concentration of all three markers was significantly higher in the group with transfusion after the completion of CPB. Moreover, GFAP levels were higher in the transfusion group and 16 h after surgery.

CONCLUSIONS

The results of the study show the safety and effectiveness of brain injury prevention strategies that consist of not conducting PRBC transfusion.

A comparison of the changes in serum lactate between surgical repair and transthoracic device closure of ventricular septal defects in pediatric patients

Objective

The purpose of this study was to compare the changes in serum lactate between surgical repair and transthoracic device closure of ventricular septal defects (VSDs) in pediatric patients.

Methods

This study was a retrospective analysis, and 314 pediatric patients with simple VSD from October 2019 to October 2021 were selected. The patients were divided into the S group (surgical repair) and the D group (transthoracic device closure). The serum lactate value at ICU admission and 6 h after operation, as well as the highest serum lactate value were collected, and the 6-h serum lactate clearance rate was calculated.

Result

Through propensity score matching, 43 pairs of cases were successfully matched. Compared with the S group, the D group had a shorter operation duration, ventilation duration, and ICU duration, as well as a lower drainage volume and total hospitalization cost. There was no significant difference between the two groups in the initial and highest serum lactate values after VSD closure, while the 6-h serum lactate value in the D group was significantly lower than that in the S group, and the 6-h serum lactate clearance rate in the D group was five times faster than that in the S group. In addition, the 6-h serum lactate clearance rate in the S group was mainly related to the operation time, CPB time, and ventilation time, while the 6-h serum lactate clearance rate in the D group was only related to the operation time.

Conclusion

The initial and highest serum lactate levels were not significantly different between surgical repair and transthoracic device closure of VSD, but the 6-h serum lactate clearance rate of device closure was five times faster than that of surgical repair.

Prognostic value of systemic inflammatory response syndrome after transcatheter aortic valve implantation

AIMS

Systemic inflammatory response syndrome (SIRS) could affect mortality after transcatheter aortic valve implantation (TAVI) up to 12 months of follow-up. The aim of this study was to evaluate the prevalence of SIRS after TAVI and its impact on all-cause mortality up to 24 months follow-up.

METHODS

We retrospectively enrolled 132 patients with symptomatic severe aortic stenosis undergoing TAVI. SIRS development during the first 72 h after the intervention was evaluated. Other postoperative complications were defined according to the Valve Academic Research Consortium 2 (VARC2). All patients underwent follow-up at 30 days and 24 months. Endpoints were 30-days and 24-months mortality.

RESULTS

Post-TAVI SIRS developed in 27 patients (20%). At 30-day follow-up, all-cause death occurred in 10 (8%) patients and SIRS occurred more frequently in patients with adverse short-term outcome (60 vs. 17%; P = 0.001). Twenty-four months all-cause death occurred in 25 (19%) patients. SIRS resulted as an independent predictor of long-term outcome [hazard ratio 3.7; 95% confidence interval (95% CI) 1.5-9; P = 0.004], along with major vascular complications (hazard ratio 4; 95% CI 1.6-9.9; P = 0.003), relevant bleedings (hazard ratio 6.4; 95% CI 1.5-28; P = 0.013) and baseline pulmonary hypertension (hazard ratio 2.4; 95% CI 1.05-5.6; P = 0.039).

CONCLUSION

Postoperative SIRS was more frequent in patients who died at 30 days follow-up. Moreover, SIRS resulted as a predictor of 24-month mortality along with vascular complications, relevant bleedings and baseline pulmonary hypertension.

Myocardial injury and inflammatory response in percutaneous device closures of pediatric patent ductus arteriosus

Background

The percutaneous device closure of patent ductus arteriosus (PDA) is widely used in clinical practice, however full data on the changes in myocardial injury and systemic inflammatory markers’ levels after PDA in children are not fully reported.

Methods

We have conducted a retrospective analysis of the medical records of 385 pediatric patients in our hospital from January 2017 to December 2019. The patients were distributed into five groups. The first four (A, B, C and D) included patients divided by the type of the surgical closure methods, namely ligation, clamping, ligation-combined suturing and ligation-combined clamping, respectively. The fifth group E comprised of percutaneous device PDA patients. All recorded medical and trial data from the five groups were statistically studied.

Results

No serious complications in the patients regardless of the classification group were reported. Our results suggested that there were no considerable differences between the groups at the baseline (with all P > 0.05). Group E demonstrated a significantly smaller operative time (42.39 ± 3.88, min) and length of hospital stay (LOS) (4.49 ± 0.50, day), less intraoperative blood loss (7.12 ± 2.09, ml) while on the other hand, a higher total hospital cost (24,001.35 ± 1152.80, RMB) than the other four groups (with all P < 0.001). Interestingly, the comparison of the inflammatory factors such as white blood cells (WBC) count, C-reactive protein (CRP), procalcitonin (PCT) and interleukin-6 (IL-6), as well as the myocardial injury markers (CKMB and troponin I) did not show a significant increase (P > 0.05) among the four groups. On the contrary, when the aforementioned factors and markers of all the surgical groups were compared to those in group E, we observed significantly higher speed and magnitude of changes in group E than those in groups A, B, C, and D (with all P < 0.001).

Conclusion

Although the percutaneous device closure of PDA is more comforting and drives fast recuperation in comparison to conventional surgery, it provokes myocardial injury and overall inflammation. Timely substantial and aggressive intervention measures such as the use of antibiotics before operation and active glucocorticoids to suppress inflammation and nourish the myocardium need be applied if the myocardial and inflammatory markers are eminent.

Neutrophil-Lymphocyte Ratio in Congenital Heart Surgery: What Is Known and What Is New?

Operative mortality after repair of congenital heart disease has improved dramatically over the past few decades. Nevertheless, there is always room for the additional mitigation of complications and mortality. Being able to anticipate adverse outcomes is clearly important, especially when using low-cost and easily accessible resources. The neutrophil-lymphocyte ratio (NLR) is defined as the ratio of the absolute neutrophil to lymphocyte count, which can be easily measured using a regular white blood cell count. Recently, preoperative NLR has been shown to be a predictor of outcomes in patients undergoing congenital heart surgery. Although it presented promising results, there are still many gaps to be filled like the normal value for children, the ideal cutoff value to predict adverse outcomes, the wide variation and its correlation with other biomarkers, and if it is a modifiable risk factor. The aim of this review is to understand the prognostic value of preoperative NLR as a biomarker predictor of outcomes in patients undergoing congenital heart surgery based on previous clinical studies and to propose future directions in order to solve the above-mentioned questions.

The association between neutrophil-lymphocyte ratio and poor outcomes following infant cardiac surgery

Background

Neutrophil–lymphocyte ratio (NLR) is a valuable indicator for evaluating inflammation and adverse outcomes after cardiac surgery. The objective of this study was to evaluate the association of perioperative NLR with clinical outcomes in infants undergoing congenital heart surgery with cardiopulmonary bypass.

Methods

We performed a retrospective review of 424 consecutive infants (≤ 1 year) undergoing cardiac surgery between January 2019 and September 2019. Neonates (≤ 28 days) and patients with incomplete NLR data were excluded. The study endpoint was a composite of poor outcomes after surgery. We assess the correlation between perioperative NLR and clinical outcomes. A receiver operating characteristic curve and multivariable logistic regression were applied to identify the prognosis performance of postoperative NLR for poor outcomes.

Results

A total of 68 (16%) infants experienced at least one of the poor outcomes. Postoperative NLR on the third day after the surgery showed the best prognostic significance (AUC = 0.763, 95%CI 0.700–0.826) among perioperative period, with a cut-off value of 2.05. Postoperative NLR was also strongly correlated with mechanical ventilation time, length of ICU and hospital stay (p < 0.001). Multivariable logistic regression revealed that elevated postoperative NLR (OR 3.722, 95%CI 1.895–7.309, p < 0.001) was an independent risk factor for poor outcomes in infants after cardiac surgery.

Conclusions

Postoperative NLR was correlated with increased mechanical ventilation time, length of ICU and hospital stay. Elevated postoperative NLR was an independent predictor for poor outcomes after cardiac surgery in infants.

Preoperative Neutrophil-Lymphocyte Ratio Can Predict Outcomes for Patients Undergoing Tetralogy of Fallot Repair

INTRODUCTION

Elevated neutrophil-lymphocyte ratio (NLR) has been associated with poorer outcomes in cyanotic patients undergoing single ventricle palliation. Little is known about this biomarker on patients with tetralogy of Fallot (TOF), the most common cyanotic congenital heart disease. Our objective is to study the impact of preoperative NLR on outcomes of TOF patients undergoing total repair.

METHODS

This retrospective study included 116 consecutive patients between January 2014 and December 2018. Preoperative NLR was measured from the last complete blood count test before the surgery. Using the cutoff value of 0.80, according to the receiver-operating characteristic (ROC) curve, the sample was divided into two groups (NLR < 0.80 and ≥ 0.80). The primary endpoint was hospital length of stay (LOS).

RESULTS

ROC curves showed that higher preoperative NLR was associated with longer hospital LOS, with an area under the curve of 0.801±0.040 (95% confidence interval 0.722 - 0.879; P<0.001). High preoperative NLR was also associated with long intensive care unit (ICU) LOS (P=0.035). Preoperative NLR predicted longer hospital LOS with a sensitivity of 63% and a specificity of 81.4%.

CONCLUSION

Higher preoperative NLR was associated with long ICU and hospital LOS in patients undergoing TOF repair.

Comparison of Postoperative Changes in Inflammatory Marker Levels Between Transthoracic and Transcatheter Device Closures of Atrial Septal Defects in Children

Objective

To explore the postoperative changes in inflammatory markers in children who underwent device closure of an atrial septal defect (ASD) via a transthoracic or transcatheter approach.

Methods

The experimental and clinical data were retrospectively collected and analyzed for a total of 53 pediatric patients between September 2018 and December 2018. According to the different treatments, 19 patients who underwent transthoracic device closure were assigned to group A, and the remaining 34 patients who underwent a transcatheter approach were assigned to group B.

Results

All patients were successfully occluded without any device-related severe complication. Compared with the preoperative levels, the postoperative levels of most inflammatory cytokines in both groups were significantly increased and reached a peak on the first day after the procedure. The level of postoperative inflammatory cytokines was significantly lower in group B than in group A. In addition, there was no significant difference in procalcitonin before and after the transcatheter approach.

Conclusion

Systemic inflammatory reactions occurred after transthoracic or transcatheter device closure of ASDs in pediatric patients. However, these inflammatory reactions were more significant in patients who underwent a transthoracic approach than in patients who underwent a transcatheter approach.

Perioperative care of the newborns with CHDs in the time of COVID-19

Coronavirus disease 2019 (COVID-19), caused by a novel betacoronavirus (SARS-CoV-2), has led to an unexpected outbreak affecting people of all ages. The first data showed that COVID-19 could cause severe pulmonary disease, cardiac injury, and death in adults, especially the elderly and those with concomitant diseases. Currently, it was demonstrated that severe COVID-19 may also develop in neonatal age, although rarely. Newborns with CHD are known to be at high risk for increased morbidity from viral lower respiratory tract infections because of underlying anatomical cardiac lesions. There are limited data on the implications of COVID-19 on patients with cardiovascular disease, especially for those with CHD. Herein, we aimed to summarise the COVID-19-specific perioperative management issues for newborns with CHD by combining available data from the perspectives of neonatology and paediatric cardiovascular surgery.

Toll-like receptor 9 and the inflammatory response to surgical trauma and cardiopulmonary bypass

Objectives

Cardiac surgery can lead to post-operative end-organ complications secondary to activation of systemic inflammatory response. We hypothesize that surgical trauma or cardiopulmonary bypass (CPB) may initiate systemic inflammatory response via release of mitochondrial DNA (mtDNA) signaling Toll-like receptor 9 (TLR9) and interleukin-6 production (IL-6).

Materials and methods

The role of TLR9 in systemic inflammatory response in cardiac surgery was studied using a murine model of sternotomy and a porcine model of sternotomy and CPB. mtDNA and IL-6 were measured with and without TLR9-antagonist treatment. To study ischemia-reperfusion injury, we utilized an ex-vivo porcine kidney model.

Results

In the rodent model (n = 15), circulating mtDNA increased 19-fold (19.29 ± 3.31, p < 0.001) and plasma IL-6 levels increased 59-fold (59.06 ± 14.98) at 1-min post-sternotomy compared to pre-sternotomy. In the murine model (n = 11), administration of TLR-9 antagonists lowered IL-6 expression post-sternotomy when compared to controls (59.06 ± 14.98 vs. 5.25 ± 1.08) indicating that TLR-9 is a positive regulator of IL-6 after sternotomy. Using porcine models (n = 10), a significant increase in circulating mtDNA was observed after CPB (Fold change 29.9 ± 4.8, p = 0.005) and along with IL-6 following renal ischaemia-reperfusion. Addition of the antioxidant sulforaphane reduced circulating mtDNA when compared to controls (FC 7.36 ± 0.61 vs. 32.0 ± 4.17 at 60 min post-CPB).

Conclusion

CPB, surgical trauma and ischemic perfusion injury trigger the release of circulating mtDNA that activates TLR-9, in turn stimulating a release of IL-6. Therefore, TLR-9 antagonists may attenuate this response and may provide a future therapeutic target whereby the systemic inflammatory response to cardiac surgery may be manipulated to improve clinical outcomes.

Is Systemic Inflammatory Response Syndrome Relevant to Pulmonary Complications and Mortality in Multiply Injured Children?

BACKGROUND

Systemic inflammatory response syndrome (SIRS) is a well-recognized phenomenon in adult trauma populations. The "initial hit" of the traumatic event is often coupled with a systemic immune response characterized by changes in vital signs and laboratory indicators. A "second hit" from surgery during this time frame often results in acute lung injury, along with deterioration of the patient's clinical condition. We hypothesized that children and adolescents would experience SIRS physiology, but would not experience adult respiratory distress syndrome (ARDS) or "second hit" related death to the extent seen in the adult populations.

METHODS

We queried the trauma database of our level 1 pediatric trauma center from January 2005 to December 2015 for patients with injury severity scores of >16. We used the electronic medical record to track SIRS criteria in patients days 1 to 4 posttrauma. Trends were examined in patients with an orthopaedic injury (OI) and with no orthopaedic injury. Patients were further subcategorized and analyzed by age group based on the convention for definition of pediatric SIRS. Patients in the orthopaedic cohort were further examined for pulmonary complications and death. Logistic regression was used to identify risk factors for SIRS physiology in the first 4 days of hospitalization.

RESULTS

81.4% (OI) and 69.1% no orthopaedic injury reached the threshold for SIRS within their first 4 days of hospitalization. Nine patients died in the hospital. Only 3 OI patients developed the criteria for ARDS, and only 3 patients with orthopaedic injuries died, 2 died within 24 hours of presentation and 1 within 48 hours, all had severe brain trauma. Increasing age groups showed increasing proportion of patients with SIRS. Increasing injury severity score and increasing age were independent predictors of SIRS during days 1 to 4.

DISCUSSION

SIRS seems to be as common in children as the reported rates for adults, and the proportion of SIRS in children increases with increasing age and injury severity. The high mortality rate and rate of ARDS observed in adults was not observed in our cohort. The presence or absence of major orthopaedic injuries was not a significant predictor. The SIRS response in polytraumatized children is poorly understood. The clinical phenomenon of acute lung injury/ARDS is observed less often in children, but the exact mechanism by which this occurs is unknown.

LEVEL OF EVIDENCE

Level III-case control.

Common inflammatory markers after cardiac surgery in infants and their relation to blood stream sepsis

Background

Limited information exists on trends of common inflammatory markers after infant heart surgery and their role in identifying post-operative sepsis.

Methods

275 consecutive infants undergoing cardiac surgery (231 with and 44 without Cardiopulmonary Bypass) were studied prospectively. Daily trends (0-4 day post-operative) of leucocyte counts, platelet counts and C-reactive protein were recorded. Association of these trends with early post-operative bloodstream sepsis, Cardiopulmonary Bypass and surgical outcomes were studied.

Observations

Trends of these inflammatory markers were noted. While off-Cardiopulmonary Bypass Surgery, and sepsis were associated with a statisticaly insignificant rise in total leucocyte count peaking on first post-operative day, Cardiopulmonary Bypass exposure was associated with significant decline (p = 0.002), more pronounced with Cardiopulmonary Bypass-exposure exceeding 150 min. Percentage of neutrophils showed a rise (maximum on first post-operative day) but no significant association with sepsis or Cardiopulmonary Bypass.Platelet counts significantly declined after surgery, with nadir on 2^nd POD (p < 0.001), the drop being more marked in patients operated on Cardiopulmonary Bypass (p < 0.005). Counts were significantly lower in patients exposed to >150 min Cardiopulmonary Bypass compared to those with shorter Cardiopulmonary Bypass. Septic patients had significantly lower platelet counts than uninfected patients, decline >2 SD from mean pre-operative level strongly associated with sepsis (p < 0.001).C-Reactive Protein levels rose markedly after surgery, peaking on 2^nd POD; levels were significantly higher if operated on Cardiopulmonary Bypass. Cardiopulmonary Bypass >150 min was associated with lower mean C-Reactive Protein on first post-operative day, but significantly higher values on third and fourth post-operative days, as compared to Cardiopulmonary Bypass <150 min. Comparison of infected versus non-infected patients showed significantly higher mean C-Reactive Protein in the former group.

Conclusion

While leucocyte count, platelet count and C-Reactive Protein emerged as useful markers of post-operative inflammatory response and reaction to Cardiopulmonary Bypass, they proved unsatisfactory predictors of early post-operative sepsis.

Changes in the levels of inflammatory markers after transthoracic device closure of ventricular septal defects in pediatric patients

BACKGROUND

Transthoracic device closure of ventricular septal defect (VSD) is widely used in the clinic, especially in China. Changes in inflammatory marker levels after transthoracic device closure of VSD in pediatric patients have not been reported.

METHODS

We retrospectively collected clinical data for 85 pediatric patients in our hospital from September 2017 to January 2018. The patients were divided into two groups according to treatment (device group vs. surgical group). The clinical and experimental data from the two groups were statistically analyzed.

RESULTS

Clinical outcomes were good in all patients without any fatal complications. Similar increasing trends in inflammatory markers (white blood cell (WBC) count, procalcitonin (PCT), C-reactive protein (CRP), and interleukin-6 (IL-6)) were found in the two groups, both of which showed noticeable systemic inflammatory responses. In addition, no significant difference in the postoperative levels of inflammatory markers was observed between these two groups.

CONCLUSIONS

Although transthoracic device closure of VSD seems to be less traumatic and involves a quicker recovery, it also induces a systemic inflammatory response as measured by WBC count and PCT, CRP and IL-6 levels, and the altered trends in inflammatory markers were similar to those of conventional surgery under CPB.

A Novel Brain Injury Biomarker Correlates with Cyanosis in Infants with Congenital Heart Disease

Cyanotic heart lesions are a complex subset of congenital heart disease (CHD) in which patients are desaturated until surgical repair or palliation. We hypothesized that a direct relationship would exist between degree of desaturation and presence of systemic inflammation and brain injury in unrepaired patients less than 1 year of age. The pre-operative desaturation with augmented systemic inflammation would predict a more complex post-operative course. Fifty patients with CHD were enrolled in this study and classified as cyanotic (O₂ ≤ 90%) or acyanotic (O₂ > 90%) based on SpO₂. Serum inflammatory mediators measured included interleukins (IL)-6, IL-8, IL-12p70, IL-10, IL-1β, tumor necrosis factor (TNF)-α, interferon (INF)-γ; macrophage inhibitory factor (MIF) and a novel brain biomarker, phosphorylated neurofilament heavy subunit (pNF-H). Twenty-two cyanotic and 28 acyanotic subjects were enrolled with SpO₂ of 78 ± 18% and 98 ± 2% (p < 0.001), respectively, and mean age of 72 days (range 2-303) and 102 days (range 1-274), respectively. Cyanotic vs acyanotic subjects had elevated serum IL-6 (6.6 ± 7.6 vs 2.9 ± 2.9 pg/ml, p = 0.019) and pNF-H (222 ± 637 vs 57 ± 121 pg/ml, p = 0.046), and both biomarkers correlated with degree of desaturation (Spearman rank-order correlation ρ = - 0.30, p = 0.037 and ρ = - 0.29 p = 0.049, respectively). Post-operative inotrope scores at 24 h and duration of mechanical ventilation correlated inversely with pre-operative oxygen saturation (ρ = - 0.380, p = 0.014 and ρ = - 0.362, p = 0.020, respectively). The degree of pre-operative desaturation correlated with a more complicated post-operative course supporting the need for advanced peri-operative therapy in this population.

Factors involved in initiation and regulation of complement lectin pathway influence postoperative outcome after pediatric cardiac surgery involving cardiopulmonary bypass

Congenital heart disease (CHD) often requires surgical intervention, and is sometimes associated with life-threatening post-operative complications. We have investigated some factors of the innate immune system involved in the initiation or regulation of complement lectin pathway activation (MASP-1, MASP-2 MASP-3, MAp19, MAp44, ficolin-3) and related them to complications and prognosis in 190 pediatric patients undergoing CHD repair with the use of cardiopulmonary bypass (CPB). Patients with MAp44 levels ≤1.81 µg/ml more frequently experienced low cardiac output syndrome (LCOS), renal insufficiency, systemic inflammatory response syndrome (SIRS) and multiorgan dysfunction (MODS). Low MASP-3 (≤5.18 µg/ml) and high MASP-1 (≥11.7 µg/ml) levels were often associated with fatal outcome. Low ficolin-3 concentrations (≤10.1 µg/ml) were more common among patients experiencing SIRS and MODS than in those without complications. However, patients suffering from SIRS and MODS with low ficolin-3 had a much better prognosis (91% survival vs. 37% among other patients; p = 0.007). A discriminating value of 12.7 µg/ml ficolin-3 yielded 8% vs. 60% mortality (p = 0.001). Our data extend the knowledge concerning involvement of proteins of the lectin pathway in development of post-CPB complications. The potential prognostic value of low preoperative MAp44 and high preoperative ficolin-3 seems promising and warrants independent confirmation.

Whole Body Periodic Acceleration (pGz) as a non-invasive preconditioning strategy for pediatric cardiac surgery

We hypothesized that pGz has cardio and neuroprotective effects due to upregulation of pathways which include eNOS, anti-apoptotic, and anti-inflammatory pathways. We analyze protein expression of these pathways in the brain of neonatal piglets, as well as report on the myocardial function after Deep Hypothermic Circulatory Arrest (DHCA) and pGz preconditioning. Animal data affirms both a cardio and neuroprotective role for pGz. These findings suggest that pGz can be a simple, non-invasive cardio and neuroprotective strategy preconditioning strategy in children requiring surgical intervention.

Assessment of Diffuse Ventricular Myocardial Fibrosis Using Native T1 in Children With Repaired Tetralogy of Fallot

BACKGROUND

Myocardial fibrosis is linked with adverse clinical outcomes in adults after tetralogy of Fallot repair (rTOF). Native T1 times (T1) by cardiac magnetic resonance have been shown to be a surrogate marker of diffuse myocardial fibrosis. The objective was to quantify native T1 in children post-rTOF and to evaluate their relationship with surgical, imaging, and clinical factors.

METHODS AND RESULTS

A retrospective cross-sectional study was performed. Midventricular native T1 were obtained in 100 children post-rTOF using a modified look-locker inversion recovery cardiac magnetic resonance sequence and compared with 35 pediatric controls. rTOF patients, aged 13.0±2.9 years, had higher indexed right ventricular (RV) end-diastolic (range 85-326 mL/m², mean 148 mL/m²) volumes, and lower RV and left ventricular (LV) ejection fractions compared with controls. RV, but not LV, T1 were higher in patients than in controls (1031±74 versus 954±32 ms, P<0.001) and female patients had higher RV T1 compared with males (1051±79 versus 1017±68 ms, P=0.02). LV T1 correlated with RV T1 (r=0.45, P<0.001), cardiopulmonary bypass (r=0.30, P=0.007), and aortic cross-clamp times (r=0.32, P=0.004). RV T1 correlated inversely with RV outflow tract gradient (r=-0.28, P=0.02). Longer aortic cross-clamp times were independently associated with LV and RV T1 on multivariable analysis. There was no association between exercise intolerance, arrhythmia, and native T1 or LV extracellular volume.

CONCLUSIONS

Children after rTOF do not have elevated LV native T1 or LV extracellular volume, but show evidence of increased RV native T1 suggestive of diffuse RV fibrosis, for which volume loading seems to be a risk factor. Surgical bypass and cross-clamp times are associated with fibrotic remodeling over a decade later.

Activation of the lectin pathway of complement by cardiopulmonary bypass contributes to the development of systemic inflammatory response syndrome after paediatric cardiac surgery

The systemic inflammatory response is a challenge in the management of paediatric patients undergoing cardiac surgery. Although multi-factorial, a contribution by the lectin pathway of complement activation has been postulated. We therefore investigated the changes in serum levels of mannose binding lectin (MBL) and activities of MBL-MBL-associated serine protease (MASP)-1 and MBL-MASP-2 complexes immediately before and during surgery, throughout the first postoperative day and at discharge from the hospital. These changes were analysed in relation to postoperative complications. Blood samples were obtained from 185 children with congenital heart disease undergoing surgical correction with the use of cardiopulmonary bypass: preoperatively (MBL-1), 15 min after initiation of cardiopulmonary bypass (CPB) (MBL-E), 30 min (MBL-2), 4 h (MBL-3), 12 h (MBL-4) and 24 h (MBL-5) post-CPB and at discharge from hospital (MBL-K). Alterations in serum MBL levels were calculated as a ratio of its serum level at subsequent time-points (MBL-2, -3, -4, -5) to the preoperative (MBL-1) value. Decreases in MBL and MBL-MASP complexes were observed in all samples, correlating with a decrease in C4 and increase in C4a, confirming activation of the lectin pathway. Changes in MBL levels between children with an uncomplicated postoperative course and those suffering from infection or low cardiac output syndrome did not differ significantly, but significant differences were observed between the SIRS and non-SIRS groups. Paediatric cardiac surgery with the use of cardiopulmonary bypass activates the complement system via the lectin pathway and the latter contributes to the development of the post-bypass systemic inflammatory response.

Comparison of Adrenal Suppression between Etomidate and Dexmedetomidine in Children with Congenital Heart Disease

Background

The aim of this study was to compare plasma cortisol concentration during anesthesia of children with congenital heart disease who received dexmedetomidine (DEX) with those who received etomidate (ETO).

Material/Methods

We recruited 99 ASA physical status II–III pediatric patients scheduled for congenital heart disease (CHD) corrective surgery and divided into them into 3 groups. Group DEX received an infusion of DEX intravenously with a bolus dose of 0.5 μg·kg⁻¹ within 10 min during anesthesia induction, followed by a maintenance dose of DEX 0.5 μg·kg⁻¹·h⁻¹. Group ETO received ETO intravenously with a bolus dose of 0.3 mg·kg⁻¹ without a maintenance dose. Group CON received routine anesthetics as controls. The preset timepoints were: before anesthesia induction (T0), at the end of induction (T1), 30 min after anesthesia induction (T2), at the time of aortic and inferior vena catheterization (T3), and at 180 min (T4) and 24 h (T5) after anesthesia induction.

Results

The cortisol concentration decreased gradually after anesthesia induction in all groups, and returned to baseline values after 24 h. The cortisol concentration was significantly lower in Group ETO children than in Group DEX or group CON at T4.

Conclusions

The plasma concentrations of cortisol decreased in CHD children after the operation, but returned to baseline after 24 h of anesthesia induction. The adrenal cortex function inhibition induced by ETO in CHD children is longer and more serious than that induced by DEX (if any) during the preoperative period.