Current Cardioplegia Practice in Pediatric Cardiac Surgery: A North American Multiinstitutional Survey

Temperature and Neurologic Outcomes in Neonates Undergoing Cardiac Surgery: A Society of Thoracic Surgeons Study

BACKGROUND

There is significant variability in postoperative neurological injury rates in patients with congenital heart disease, with early injuries impacting long-term neurodevelopmental outcomes; therefore, there is an urgent need for identifying effective strategies to mitigate such injuries.

OBJECTIVES

This study aims to assess the association between nadir intraoperative temperature (NIT) and early neurological outcomes in neonates undergoing congenital heart surgery.

METHODS

Analyzing data from 24,345 neonatal cardiac operations from the Society for Thoracic Surgeons Congenital Heart Surgery Database between 2010 and 2019, NIT was assessed using a mixed-effect logistic regression model, targeting major neurological injury (stroke, seizure, or deficit at discharge) as a primary endpoint.

RESULTS

The study observed a shift from hypothermic circulatory arrest to cerebral perfusion with an increase in mean nadir temperature from 23.9 °C to 25.6 °C (P < 0.0001). Major neurological injury was noted in 4.9% of the cohort, with variations based on surgical procedure. After adjusting for risk, NIT was not significantly associated with major neurological injuries overall, but a lower NIT showed protective effects in the Norwood subgroup. Factors increasing the risk of major neurological injury included younger age at surgery, the Norwood procedure, longer cardiopulmonary bypass times, younger gestational age, presence of noncardiac abnormalities, and chromosomal anomalies.

CONCLUSIONS

Whereas neurological injuries are prevalent after neonatal cardiac surgery, current practices lean towards higher core temperatures. This trend is supported by the nonsignificant impact of NIT on neurological outcomes. However, lower NIT in the Norwood subgroup indicates that reduced temperatures may be beneficial amidst specific risk factors.

The Potential Neurological Impact of Intraoperative Hyponatremia Using Histidine-Tryptophan-Ketoglutarate Cardioplegia Infusion in Adult Cardiac Surgery

Background and Objectives: The relationship between histidine-tryptophan-ketoglutarate (HTK)-induced hyponatremia and brain injury in adult cardiac surgery patients is unclear. This study analyzed postoperative neurological outcomes after intraoperative HTK cardioplegia infusion. Materials and Methods: A prospective cohort study was conducted on 60 adult patients who underwent cardiac surgery with cardiopulmonary bypass. Of these patients, 13 and 47 received HTK infusion and conventional hyperkalemic cardioplegia, respectively. The patients' baseline characteristics, intraoperative data, brain injury markers, Mini-Mental State Examination (MMSE) scores, and quantitative electroencephalography (qEEG) data were collected. Electrolyte changes during cardiopulmonary bypass, the degree of hyponatremia, and any associated brain insults were evaluated. Results: The HTK group presented with acute hyponatremia during cardiopulmonary bypass, which was intraoperatively corrected through ultrafiltration and normal saline administration. Postoperative sodium levels were higher in the HTK group than in the conventional cardioplegia group. The change in neuron-specific enolase levels after cardiopulmonary bypass was significantly higher in the HTK group (p = 0.043). The changes showed no significant differences using case-control matching. qEEG analysis revealed a significant increase in relative delta power in the HTK group on postoperative day (POD) 7 (p = 0.018); however, no significant changes were noted on POD 60. The MMSE scores were not significantly different between the two groups on POD 7 and POD 60. Conclusions: HTK-induced acute hyponatremia and rapid correction with normal saline during adult cardiac surgeries were associated with a potential short-term but not long-term neurological impact. Further studies are required to determine the necessity of correction for HTK-induced hyponatremia.

Myocardial protection in paediatric cardiac surgery: building an evidence-based strategy

Cardioplegia is fundamental to the surgical repair of congenital heart defects by protecting the heart against ischaemia/reperfusion injury, characterised by low cardiac output and troponin release in the early postoperative period. The immature myocardium exhibits structural, physiological and metabolic differences from the adult heart, with a greater sensitivity to calcium overload-mediated injury during reperfusion. Del Nido cardioplegia was designed specifically to protect the immature heart, is widely used in North America and may provide better myocardial protection in children; however, it has not been commercially available in the UK, where most centres use St Thomas' blood cardioplegia. There are no phase 3 clinical trials in children to support one solution over another and this lack of evidence, combined with variations in practice, suggests the presence of clinical equipoise. The best cardioplegia solution for use in children, and the impact of age and other clinical factors remain unknown. In this Hunterian lecture, I propose an evidence-based strategy to improve myocardial protection during cardiac surgery in children through: (1) conducting multicentre clinical trials of established techniques; (2) improving our knowledge of ischaemia/reperfusion injury in the setting of cardioplegic arrest; (3) applying this to drive innovation, moving beyond current cardioplegia solutions; (4) empowering personalised medicine, through combining clinical and genomic data, including ethnic diversity; and (5) understanding the impact of cardioplegic arrest on the late outcomes that matter to patients and their families.

Comparison of Bretschneider HTK and Blood Cardioplegia (4:1): A Prospective Randomized Study

BACKGROUND

We compared the effect of intermittent blood and histidine-tryptophan-ketoglutarate (HTK) solution of Bretschneider on myocardial histopathology and perioperative outcome.

METHODS

Forty adult cardiac surgery patients were grouped into two (n = 20 for each): (1) Intermittent blood cardioplegia (IBC): had repeated cold 4:1 blood cardioplegia and (2) HTK: had a single dose of cold HTK for cardioprotection. Creatine kinase (CK)-MB, Troponin-I (cTn-I), pH, and lactate were studied in coronary sinus blood before and after aortic cross-clamping (AXC) and systemic blood at postoperative 6th, 24th, and 48th hours. Myocardial biopsy was performed before and after AXC for light microscopy. Vacuolation, inflammation, edema, and glycogen were graded semiquantitatively (from 0 to 3). The myocardial apoptotic index was evaluated via the terminal deoxynucleotidyl transferase dUTP nick end labeling.

RESULTS

There were no differences in perioperative clinical outcomes between the groups. The coronary sinus samples after AXC were more acidotic (7.15 ± 0.14 vs. 7.32 ± 0.07, p = 0.001) and revealed higher CK-MB (21.0 ± 12.81 vs. 12.60 ± 11.80, p = 0.008) in HTK compared with IBC. The HTK had significantly a higher amount of erythrocyte suspension intraoperatively compared with IBC (0.21 ± 0.53 vs. 1.68 ± 0.93 U, p = 0.001). Microscopically, myocardial edema was more pronounced in HTK compared with IBC after AXC (2.25 ± 0.91 vs. 1.50 ± 0.04, p = 0.013). While a significant increase in the apoptotic index was seen after AXC in both groups (p = 0.001), no difference was detected between the groups (p = 0.417).

CONCLUSION

IBC and HTK have a similar clinical outcome and protective effect, except for more pronounced myocardial edema and increased need for intraoperative transfusion with HTK.

Additive Effects of Esaxerenone, a Nonsteroidal Mineralocorticoid Receptor Blocker, on Cardioplegic Arrest in Rat Hearts

PURPOSE

Esaxerenone, a mineralocorticoid receptor blocker, attenuates global ischemia-induced myocardial damage and coronary endothelial dysfunction. This study aimed to determine whether esaxerenone exerted cardioprotective effects against cardioplegic arrest in Wistar rat hearts.

METHODS

Isolated male Wistar rat hearts aerobically perfused via the Langendorff method for 20 min were randomly allocated to the Control (n = 6; perfused for an additional 10 min and subjected to no treatment) or Esax (n = 6; perfused with 0.1 μmol/L esaxerenone in perfusate for 10 min before ischemia) groups. Hearts in both groups were perfused with St. Thomas' Hospital No. 2 solution (STH2) for 2 min and subjected to 28 min of global ischemia. The recovery of left ventricular developed pressure (LVDP) and total troponin T leakage were measured after reperfusion.

RESULTS

The final recovery of LVDP (expressed as a percentage of pre-ischemic value) in the Control and Esax groups was 50.8 ± 3.5% and 62.1 ± 5.6%, respectively (p <0.05, Esax vs. Control). The total troponin T leakage in the Control and Esax groups was 138.8 ± 18.5 ng/g heart wt and 74.3 ± 18.6 ng/g heart wt, respectively (p <0.05, Esax vs. Control).

CONCLUSION

The administration of esaxerenone before cardioplegic arrest enhanced the cardioprotective effect exerted by STH2.

Warm versus cold blood cardioplegia in paediatric congenital heart surgery: a randomized trial

OBJECTIVES

Intermittent cold blood cardioplegia is commonly used in children, whereas intermittent warm blood cardioplegia is widely used in adults. We aimed to compare clinical and biochemical outcomes with these 2 methods.

METHODS

A single-centre, randomized controlled trial was conducted to compare the effectiveness of warm (≥34°C) versus cold (4-6°C) antegrade cardioplegia in children. The primary outcome was cardiac troponin T over the 1st 48 postoperative hours. Intensive care teams were blinded to group allocation. Outcomes were compared by intention-to-treat using linear mixed-effects, logistic or Cox regression.

RESULTS

97 participants with median age of 1.2 years were randomized (49 to warm, 48 to cold cardioplegia); 59 participants (61%) had a risk-adjusted congenital heart surgery score of 3 or above. There were no deaths and 92 participants were followed to 3-months. Troponin release was similar in both groups [geometric mean ratio 1.07; 95% confidence interval (CI) 0.79-1.44; P = 0.66], as were other cardiac function measures (echocardiography, arterial and venous blood gases, vasoactive-inotrope score, arrhythmias). Intensive care stay was on average 14.6 h longer in the warm group (hazard ratio 0.52; 95% CI 0.34-0.79; P = 0.003), with a trend towards longer overall hospital stays (hazard ratio 0.66; 95% CI 0.43-1.02; P = 0.060) compared with the cold group. This could be related to more unplanned reoperations on bypass in the warm group compared to cold group (3 vs 1).

CONCLUSIONS

Warm blood cardioplegia is a safe and reproducible technique but does not provide superior myocardial protection in paediatric heart surgery.

Custodiol over cold blood cardioplegia in minimal invasive cardiac valve surgery

Background

Custodiol has been used as a multi-organ preservation solution and as cardioplegia in cardiac surgery in several nations, but not elsewhere in the globe. Long procedures can be completed without interruption with just one dosage, which offers myocardial protection for up to three hours.

Objective

This study compared the effects of Custodiol and Cold Blood Cardioplegia on the protection of the myocardium during minimally invasive cardiac valve surgery.

Patients and methods

On 82 patients receiving Custodiol and Cold Blood Cardioplegia during Minimally Invasive Cardiac Valve Surgery, a prospective research was done. The investigation took place between January 2021 and March 2022. There were two groups of patients. There were 41 patients in Group (A) who received Custodiol cardioplegia, and there were 41 patients in Group (B) who received cold blood cardioplegia. The study’s secondary endpoint was the measurement of Left ventricular ejection fraction in serial echocardiograms, whereas the study’s primary result was the detection of increased cardiac enzymes in serial measurements, signifying myocardial damage.

Results

Our data’s statistical analysis revealed that none of the outcomes under investigation exhibited a statistically significant difference between groups.

Conclusion

As determined by CK-MB and EF, a single-dose of antegrade cold custodiol cardioplegia during minimally invasive cardiac surgery is just as effective at preserving the myocardial as repeated antegrade cold blood cardioplegia.

Comparison between Del Nido and conventional blood cardioplegia in pediatric open-heart surgery

BACKGROUND

Del Nido cardioplegia (DNc) was designed for superior myocardial protection during cardiopulmonary bypass (CPB). We conducted a retrospective review to explore if DNc was associated with increase in systemic ventricle dysfunction (sVD) following pediatric CPB.

METHODS AND RESULTS

This single-center, retrospective study included 1534 patients undergoing CPB between 2013 and 2016, 997 prior to center-wide conversion to DNc and 537 following. The primary outcome was new postoperative ≥moderate sVD by echocardiogram. Secondary outcomes included sVD of any severity and right ventricular dysfunction. Data was evaluated by interrupted time-series analysis. Groups had similar cardiac diagnoses and surgical complexity. Del Nido cardioplegia was associated with longer median (IQR) CPB [117 (84-158) vs 108 (81-154), p = 0.04], and aortic cross-clamp [83 (55-119) vs 76 (53-106), p = 0.03], and fewer cardioplegia doses [2 (1-2) vs 3 (2-4), p < 0.0001]. Mortality was similar in both groups. Frequency of sVD was unchanged following DNc, including predetermine subgroups (neonates, infants, and prolonged cross-clamp). Logistic regression showed a significant rise in right ventricular dysfunction (OR 5.886 [95% CI: 0.588, 11.185], p = 0.03) but similar slope.

CONCLUSIONS

Use of DNc was not associated with increased in reported sVD, and provided similar myocardical protection to the systemic ventricle compared to conventional cardioplegia but may possibly impact right ventricular function. Studies evaluating quantitative systolic and diastolic function are needed.

Del Nido cardioplegia for myocardial protection in adult cardiac surgery: a systematic review and update meta-analysis

OBJECTIVE

Although the application of del Nido cardioplegia solution (DNC) in adult cardiac surgery is accumulating, the feasibility and safety of this myocardial protection strategy in adults remains controversial. We aimed to update our previous meta-analysis to determine the myocardial protective effect of DNC versus conventional cardioplegia (CC) in adult cardiac surgery.

METHODS

A comprehensive literature search was performed using PubMed, EMBASE, the Cochrane Library, and International Clinical Trials Registry Platform databases through November 2020.

RESULTS

Thirty-seven observational studies and four randomized controlled trials (RCTs) including 21,779 patients were identified. The DNC group was associated with decreased postoperative cardiac enzymes [troponin T (cTnT) and creatine kinase-MB (CK-MB)] [standardized mean differences (SMD): -0.59, 95% confidence interval (CI): -0.99 to -0.19, p = 0.004], cardiopulmonary bypass (CPB) time (MD: -9.31, 95% CI: -13.10 to -5.51, p < 0.00001), aortic cross-clamp (ACC) time (MD: -7.20, 95% CI: -10.31 to -4.09, p < 0.00001), and cardioplegia volume (SMD: -1.95, 95% CI: -2.46 to -1.44, p < 0.00001). Intraoperative defibrillation requirement was less in the DNC group [relative risk (RR): 0.50, 95% CI: 0.33 to 0.75, p = 0.0007]. The pooled analysis revealed no significant difference in operative mortality among the patients assigned to DNC and those undergoing CC.

CONCLUSION

In adult cardiac surgery, compared to CC, myocardial protection used with DNC yield similar or better short-term clinical outcomes. More high-quality trials and RCTs reflecting long-term follow-up morbidity and mortality are required in the future to confirm these findings.

Proton magnetic resonance spectroscopy assessment of neonatal brain metabolism during cardiopulmonary bypass surgery

Here, we report on the development and performance of a robust 3-T single-voxel proton magnetic resonance spectroscopy (¹ H MRS) experimental protocol and data analysis pipeline for quantifying brain metabolism during cardiopulmonary bypass (CPB) surgery in a neonatal porcine model, with the overall goal of elucidating primary mechanisms of brain injury associated with these procedures. The specific aims were to assess which metabolic processes can be reliably interrogated by ¹ H MRS on a 3-T clinical scanner and to provide an initial assessment of brain metabolism during deep hypothermia cardiac arrest (DHCA) surgery and recovery. Fourteen neonatal pigs underwent CPB surgery while placed in a 3-T MRI scanner for 18, 28, and 37°C DHCA studies under hyperglycemic, euglycemic, and hypoglycemic conditions. Total imaging times, including baseline measurements, circulatory arrest (CA), and recovery averaged 3 h/animal, during which 30-40 single-voxel ¹ H MRS spectra (sLASER pulse sequence, TR/TE = 2000/30 ms, 64 or 128 averages) were acquired from a 2.2-cc right midbrain voxel. ¹ H MRS at 3 T was able to reliably quantify (1) anaerobic metabolism via depletion of brain glucose and the associated build-up of lactate during CA, (2) phosphocreatine (PCr) to creatine (Cr) conversion during CA and subsequent recovery upon reperfusion, (3) a robust increase in the glutamine-to-glutamate (Gln/Glu) ratio during the post-CA recovery period, and (4) a broadening of the water peak during CA. In vivo ¹ H MRS at 3 T can reliably quantify subtle metabolic brain changes previously deemed challenging to interrogate, including brain glucose concentrations even under hypoglycemic conditions, ATP usage via the conversion of PCr to Cr, and differential changes in Glu and Gln. Observed metabolic changes during CPB surgery of a neonatal porcine model provide new insights into possible mechanisms for prevention of neuronal injury.

Recent advancements in pediatric cardiopulmonary bypass technology for better outcomes of pediatric cardiac surgery

Background

Pediatric cardiac surgery is in itself very enigmatic and individualized. Presently, there has been a slew of new developments aimed primarily toward pediatric cardiopulmonary bypass for safer, patient-centered pediatric cardiac surgery. Still, lot of technological challenges need to be resolved, and their safer application in pediatric and neonate patients requires further refinement.

Main body of the abstract

Considering various significant yet unresolved issues of pediatric cardiac bypass, an exhaustive literature search was done on various internet databases with standard keywords. There are various new recent improvements; as the first oxygenator explicitly designed for neonatal patients; pediatric oxygenators with low prime volumes and surface areas that allow flows up to 2 L/min; pediatric oxygenators with integrated arterial filters; and miniature ultrafiltration devices that allow for high rates of ultrafiltrate removal. These advancements can significantly reduce cardiopulmonary bypass circuit surface areas and prime volumes. These advancements could reduce or eliminate the requirement for homologous red blood cells during or after surgery with reduction or eliminate bypass-related hemodilution, and inflammation. Because of the immaturity of the neonatal hemostatic system, conventional coagulation tests alone are insufficient to guide neonatal hemostatic therapy. Myocardial preservation techniques, safe temperature with duration are still debatable and yet to be fully explored.

Short conclusion

This review is based on Standards for Quality Improvement Reporting Excellence guidelines to provide a framework for reporting new knowledge to find better management strategy for pediatric cardiac cases.

Acute Changes in Myocardial Expression of Heat Shock Proteins and Apoptotic Response Following Blood, delNido, or Custodiol Cardioplegia in Infants Undergoing Open-Heart Surgery

Stress caused by cardioplegic ischemic arrest was shown to alter the expression levels of heat shock proteins (Hsp), but little is known about their effects, particularly on pediatric hearts. This study aimed to investigate whether myocardial cellular stress and apoptotic response changes due to different cardioplegia (CP) solutions during cardiopulmonary bypass (CPB) in infants and to determine their influence on surgical/clinical outcomes. Therefore, twenty-seven infants for surgical closure of ventricular septal defect were randomly assigned to a CP solution: normothermic blood (BCP), delNido (dNCP), and Custodiol (CCP). Hsp levels and apoptosis were determined by immunoblotting in cardiac tissue from the right atrium before and after CP, and their correlations with cardiac parameters were evaluated. No significant change was observed in Hsp27 levels. Hsp60, Hsp70, and Hsp90 levels decreased significantly in the BCP-group but increased markedly in the CCP-group. Decreased Hsp60 and increased Hsp70 expression were detected in dNCP-group. Importantly, apoptosis was not observed in dNCP- and CCP-groups, whereas marked increases in cleaved caspase-3 and -8 were determined after BCP. Serum cardiac troponin-I (cTn-I), myocardial injury marker, was markedly lower in the BCP- and dNCP-groups than CCP. Additionally, Hsp60, Hsp70, and Hsp90 levels were positively correlated with aortic cross-clamp time, total perfusion time, and cTn-I release. Our findings show that dNCP provides the most effective myocardial preservation in pediatric open-heart surgery and indicate that an increase in Hsp70 expression may be associated with a cardioprotective effect, while an increase in Hsp60 and Hsp90 levels may be an indicator of myocardial damage during CPB.

Are outcomes in congenital cardiac surgery better than ever?

BACKGROUND AND AIM OF THE STUDY

Congenital heart disease is the most common congenital defect among infants born in the United States. Within the first year of life, 1 in 4 of these infants will need surgery. Only one generation removed from an overall mortality of 14%, many changes have been introduced into the field. Have these changes measurably improved outcomes?

METHODS

The literature search was conducted through PubMed MEDLINE and Google Scholar from inception to October 31, 2021. Ultimately, 78 publications were chosen for inclusion.

RESULTS

The outcome of overall mortality has experienced continuous improvements in the modern era of the specialty despite the performance of more technically demanding surgeries on patients with complex comorbidities. This modality does not account for case-mix, however. In turn, clinical outcomes have not been consistent from center to center. Furthermore, variation in practice between institutions has also been documented. A recurring theme in the literature is a movement toward standardization and universalization. Examples include mortality risk-stratification that has allowed direct comparison of outcomes between programs and improved definitions of morbidities which provide an enhanced framework for diagnosis and management.

CONCLUSIONS

Overall mortality is now below 3%, which suggests that more patients are surviving their interventions than in any previous era in congenital cardiac surgery. Focus has transitioned from survival to improving the quality of life in the survivors by decreasing the incidence of morbidity and associated long-term effects. With the transformation toward standardization and interinstitutional collaboration, future advancements are expected.

Clinical outcomes of del nido cardioplegia and st thomas blood cardioplegia in neonatal congenital heart surgery

Objectives:

Cardioplegia is essential for adequate myocardial protection. There continues to remain ambiguity regarding the ideal cardioplegia for adequate myocardial protection in congenital heart surgery. This study compares clinical outcomes using St Thomas II solution and Del Nido cardioplegia in neonates undergoing cardiac surgery.

Methods:

All neonates (<30 days) from 2011 to 2017 who underwent surgery requiring cardioplegic arrest were analyzed retrospectively. We divided the cohort into two groups depending on cardioplegia received, as group A (Blood cardioplegia with St Thomas II solution, n = 56) and group B (Del Nido cardioplegia, n = 48). Various demographic, intraoperative, early postoperative, and discharge variables were analyzed.

Results:

Two groups were similar in age, gender, pre-operative diagnosis, and risk category. Cardiopulmonary bypass (CPB) time (P = 0.002), aortic cross-clamp (ACC) time (P = 0.018), and the number of doses of cardioplegia (P < 0.001) were significantly lower with Del Nido group. Though vasoactive inotropic score (VIS) (P = 0.036) was high during the first 24 h in the immediate postoperative period in group A, there was no difference in early mortality among both groups (P = 0.749). Both groups did not show significant differences related to various postoperative and discharge variables.

Conclusion:

When compared to St. Thomas solution, the use of Del Nido cardioplegia solution in neonates is associated with a significant decrease in CPB and ACC times and VIS in the first 24 h after surgery. The choice of cardioplegia (St Thomas/Del Nido) in neonates does not affect early mortality and early postoperative clinical outcomes.

Modified del Nido versus blood cardioplegia in congenital cardiac surgery

BACKGROUND

Lactated Ringer-based del Nido cardioplegia has been reported to be safe for acquired cardiac surgery. The original Plasma-Lyte-based solution has been proved for congenital cardiac surgery but its modification has not been adequately examined. We compared the clinical outcomes of congenital cardiac surgery using lactated Ringer-based del Nido cardioplegia versus cold blood cardioplegia.

METHODS

Between September 2018 and November 2020, 116 consecutive patients with congenital heart disease undergoing operations with cardioplegic arrest performed by a single surgeon at Faculty of Medicine Siriraj hospital; 66 with modified del Nido solution and 50 with institutional's blood cardioplegia. The patient risk profiles, operative details, mortality rates, care durations, inotrope use, blood transfusion and complications were compared.

RESULTS

Preoperative characteristics were similar between groups, including median age (2.5 vs. 3.1 years; p = 0.49), size, and gender. The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery score of 3 to 5 was more prevalent in the del Nido group (24.2% vs. 10%; p = 0.049). There were 4 deaths in the modified del Nido group (risk category score of 4) but none in the cold blood group (p = 0.13). There was no significant difference in median intubation duration, length of intensive care unit stay, and vasoactive medications immediately and 24 h after the operation. The del Nido group required 70 to 100 ml less blood transfusion (p = 0.04). All complications were similar between the two groups.

CONCLUSIONS

Clinical outcomes of lactated Ringer-based del Nido cardioplegia were comparable to those of blood cardioplegia in congenital cardiac surgery.

Comparison of Del Nido and Blood Cardioplegia in Pediatric Patients Undergoing Surgical Repair for Congenital Heart Disease

The aim of the study is to investigate the impact of two different cardioplegia solutions, the del Nido (dN) and blood cardioplegia (BC), on postoperative troponin concentrations, vasoactive-inotrope score, and length of hospital stay in pediatric patients undergoing cardiovascular surgery for CHD. 80 subjects aged between 1 and 120 months who were scheduled for surgical repair for a CHD were prospectively enrolled in this study. Study subjects were allocated to one of the study groups using simple randomization technique as follows: The del Nido cardioplegia group (n = 40, median age 8.5 [5.5-14] months) and conventional blood cardioplegia group (n = 40, median age 11 [5-36] months). Aortic cross-clamp time and cardiopulmonary bypass time were recorded in all subjects. Troponin I and vasoactive-inotropic score, which indicates the amount of cardiovascular support by various inotropes or vasopressors, were recorded following the repair. The difference in troponin I, vasoactive-inotropic score (VIS), length of ICU stay, and length of hospital stay between the two groups was the primary outcome measure of this study. The volume of cardioplegia was significantly lower in dN group than that of the BC group (p < 0.001). Cardiopulmonary bypass time and aortic cross-clamp time were significantly shorter in subjects receiving dN cardioplegia than those receiving BC (p = 0.006, and p = 0.001, respectively). Subjects assigned to BC had higher Troponin I concentrations at postoperative 24th hour compared to subjects receiving dN cardioplegia [1.60 (0.92-2.49) ng/mL vs. 1.03 (0.55-1.83) ng/mL, p = 0.045]. VIS was also significantly higher in BC group at 24th [10 (10-13) vs. 10 (5-10), p = 0.032] and 48th hours [10 (1.5-10) vs. 0 (0-10), p = 0.005] compared to that of the dN cardioplegia group. The median extubation time was 7.5 (3.5-20.5) hours in dN cardioplegia group and 5 (4-10) hours in the BC group (p = 0.384). There were no significant differences between the groups with respect to the length of ICU stay and length of hospital stay. No mortality and no significant arrhythmias requiring medical or electrical cardioversion were noted in any of the groups. In conclusion, dN cardioplegia provides shorter aortic cross-clamp time and cardiopulmonary bypass time, and lower postoperative troponin I concentration and vasoactive-inotrope scores compared to BC in pediatric subjects undergoing surgical repair for CHD. However, lengths of ICU and hospital stay are similar in dN cardioplegia and BC groups.

Myocardial protection: a forgotten modality

The goals of a cardiac surgical procedure are both technical excellence and complete protection of cardiac function. Cardioplegia is used almost universally to protect the heart and provide a quiet bloodless field for surgical accuracy. Yet, despite the importance of myocardial protection in cardiac surgery, manuscripts or dedicated sessions at major meetings on this subject have become relatively rare, as though contemporary techniques now make them unnecessary. Nevertheless, septal dysfunction and haemodynamic support (inotropes, intra-aortic balloon pump, assist devices) are common in postoperative patients, indicating that myocardial damage following cardiac surgery is still prevalent with current cardioplegic techniques and solutions. This article first describes why cardiac enzymes and septal function are the ideal markers for determining the adequacy of myocardial protection. It also describes the underappreciated consequences of postoperative cardiac enzyme release or septal dysfunction (which currently occurs in 40-80% of patients) from inadequate protection, and how they directly correlate with early and especially late mortality. Finally, it reviews the various myocardial protection techniques available to provide a detailed understanding of the cardioplegic methods that can be utilized to protect the heart. This will allow surgeons to critically assess their current method of protection and, if needed, make necessary changes to provide their patients with optimal protection.

Initial experience with del Nido cardioplegia solution at a Pediatric and Congenital Cardiac Surgery Program in Brazil

OBJECTIVE

The aim of this study was to evaluate outcome measures between our standard multidose cardioplegia protocol and a del Nido cardioplegia protocol in congenital heart surgery patients.

METHODS

Retrospective single-center study including 250 consecutive patients that received del Nido cardioplegia (DN group) with a mandatory reperfusion period of 30% of cross clamp time and 250 patients that received a modified St. Thomas' solution (ST group). Groups were matched by age, weight, gender, and Risk Adjustment for Congenital Heart Surgery (RACHS-1) scores. Preoperative hematocrit and oxygen saturation were also recorded. Outcomes analyzed were the vasoactive inotropic score (VIS), lactate, ventilation time, ventricular dysfunction with low cardiac output syndrome (LCOS), intensive care unit (ICU) length of stay (LOS), hospital LOS, bypass and aortic cross-clamp times, and in-hospital mortality.

RESULTS

Both groups were comparable demographically. Statistically significant differences (p ⩽ 0.05) were noted for cardiac dysfunction with LCOS, hematocrit at end of surgery (p = 0.0038), VIS on ICU admission and at end of surgery (p = 0.0111), and ICU LOS (p = 0.00118) with patients in the DN group having more desirable values for those parameters. Other outcome measures did not reach statistical significance.

CONCLUSION

In our congenital cardiac surgery population, del Nido cardioplegia strategy was associated with less ventricular dysfunction with LCOS, a lower VIS and decreased ICU LOS compared with patients that received our standard myocardial protection using a modified St. Thomas' solution. Despite the limitation of this study, including its retrospective nature and cohort size, these data supported our transition to incorporate del Nido cardioplegia solution with a mandatory reperfusion period as the preferred myocardial protection method in our program.

First Harvest of Pediatric and Congenital Heart Surgery Multicenter Database in Turkey: Novel Application of Real-Time Online Reporting

OBJECTIVES

A new congenital heart surgery database (CKCV) with real-time online reporting function was recently developed in Turkey. All standard international parameters were used, but Aristotle Comprehensive Complexity score was modified. In this study, the first analysis of the CKCV Database is reported.

METHODS

The CKCV Database included 2307 procedures from 12 centers between January 2018 and March 2020. All parameters, including 10 real-time online reports, which represent the number of centers, number and mortality rates of all procedures, number of extracorporeal membrane oxygenation (ECMO) and results, details of postoperative complications, age-group statistics, analysis for priority status, mean intensive care and hospital stay durations of the procedures, results of Aristotle Basic, Modified Aristotle Comprehensive (MACC) and Society of Thoracic Surgeons-European Association (STAT) Score Categories, comparison of centers were analyzed.

RESULTS

Most common 10 procedures were ventricular septal defect (VSD) repair (n = 273), tetralogy of Fallot (TOF) repair (n = 243), atrial septal defect (ASD) repair (n = 181), complete AVSD repair (n = 95), cavopulmonary anastomosis (n = 81), systemic to pulmonary shunt (n = 79), modified Fontan (n = 71), subaortic resection, (n = 66) PA banding (n = 66), and arterial switch operation (n = 66). Cardiopulmonary bypass was used in 84.6% of the procedures. Overall mortality rate was 6.0%. A total of 618 major and 570 minor complications were observed in 333 and 412 patients, respectively. According to six MACC categories, number of the patients and mortality rates were I (293; 0.3%); II (713; 1.4%); III (601; 3.3%); IV (607; 12%); V (84; 35.7%); and VI (9; 55.6%), respectively. Analysis of five STAT Categories showed 0.7, 3.8, 5.4, 14.9, and 54.7% mortality rates.

CONCLUSIONS

CKCV Database has a great potential for nationwide quality improvement studies. Users could instantly analyze and compare their results to national and international aggregate data using a real-time online reporting function. This is the first multicenter congenital database study in Turkey.

Safety of Normothermic Cardiopulmonary Bypass in Pediatric Cardiac Surgery: A System Review and Meta-Analysis

Objectives: Hypothermic cardiopulmonary bypass (HCPB) has been used successfully in cardiac surgery for more than half a century, although adverse effects have been reported with its use. Many studies on temperature management during CPB published to date have shown that normothermic CPB (NCPB) provides more benefits to children undergoing cardiac surgery. The present meta-analysis investigated the effect of NCPB on clinical outcomes based on results of randomized controlled trials and observational studies on pediatric cardiac surgery. Methods: Databases such as PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and Clinical Trials.gov were searched from inception to May 2021 to identify relevant studies published in English. Results: The present meta-analysis included 13 studies characterizing a total of 837 pediatric patients. The random effects model exhibited that the NCPB group had reduced revision for postoperative bleeding [odds ratio (OR): 0.11; 95% confidence interval (CI): 0.01-0.89; I ² = 0%, P = 0.04], serum lactate 2-4 h after CPB (mean difference: -0.60; 95% CI: -1.09 to -0.11; I ² = 82%, P = 0.02), serum creatinemia 24 h after CPB (mean difference: -2.73; 95% CI: -5.06 to -0.39; I ² = 83%, P = 0.02), serum creatinemia 48 h after CPB (mean difference: -2.08; 95% CI: -2.78 to -1.39; I ² = 0%, P < 0.05), CPB time (mean difference: -19.10, 95% CI: -32.03 to -6.18; I ² = 96%, P = 0.04), and major adverse events (OR: 0.37; 95% CI: 0.15-0.93; Z = 2.12, P = 0.03) after simple congenital surgery compared with the HCPB group. Conclusion: NCPB is as safe as HCPB in pediatric congenital heart surgery. Moreover, NCPB provides more advantages than HCPB in simple congenital heart surgery.

Investigation of myocardial protection during pediatric CPB: Practical experience in 100 Chinese hospitals

Many measures have been proposed for myocardial protection in pediatric congenital heart surgeries, but little data is available for China. This study investigates myocardial protection strategies in pediatric cardiopulmonary bypass (CPB) throughout China. Online questionnaires were delivered to 100 hospitals in 27 provinces. The number of yearly on-pump pediatric cardiovascular surgeries in these hospitals varied greatly. About 91.0% of respondents believe that each surgery should have at least two perfusionists, while only 64.0% of hospitals actually met this requirement. For pediatric patients, crystalloid cardioplegia was more prevalent than blood-based cardioplegia. Histidine-tryptophan-ketoglutarate solution and St. Thomas crystalloid solution were dominant among crystalloid cardioplegia. Del Nido cardioplegia and St. Thomas blood-based cardioplegia ranked the top two in the popularity of blood-based cardioplegia. Dosages varied among different kinds of cardioplegia. In the choice of different cardioplegia, perfusionists mainly focused on myocardial protective effect and cost. Hypothermia of cardioplegia solution was maintained by ice buckets in 3/4 of the hospitals in this survey. In conclusion, the essence of myocardial protection management during pediatric CPB was cardiac arrest induced by cardioplegia under systemic hypothermia. However, there is no uniform standard for the type of cardioplegia, or dosages. Therefore, well-designed multicenter randomized controlled trials are warranted to provide tangible evidence for myocardial protection of cardioplegia in pediatric CPB.

Comparison of del Nido and histidine-tryptophan-ketoglutarate cardioplegic solutions in minimally invasive cardiac surgery

OBJECTIVE

We examined the safety and efficacy of del Nido cardioplegic solution compared with histidine-tryptophan-ketoglutarate cardioplegic solution in minimally invasive cardiac surgery.

METHODS

Patients who underwent minimally invasive cardiac surgery using del Nido or histidine-tryptophan-ketoglutarate from 2015 to 2019 were enrolled. Various clinical outcomes were compared between the groups. Postoperative laboratory findings including the levels of electrolytes, cardiac enzymes (creatine kinase-MB and troponin I), and serial blood lactate were also measured and compared. Based on 28 baseline covariates, propensity score matching was performed to reduce selection bias.

RESULTS

Among 766 patients, del Nido and histidine-tryptophan-ketoglutarate were used in 330 patients (43.1%) and 436 patients (56.9%), respectively. There were no significant intergroup differences in postoperative clinical outcomes and early adverse outcomes among 228 pairs of propensity score-matched patients. Immediate postoperative sodium levels were within the normal range in both groups without a significant difference (P = .50). However, peak creatine kinase-MB (median, 31.9 vs 37.7 ng/mL, P = .026) and troponin I (6.9 vs 9.1 ng/mL, P = .014) levels were significantly lower in the del Nido group. Linear regression analysis revealed a significant association between the peak cardiac enzyme levels and the cardiac ischemic time depending on the cardioplegia type, with lower cardiac isoenzymes for del Nido over histidine-tryptophan-ketoglutarate (P < .001) until the crossover point at the cardiac ischemic time over 100 minutes.

CONCLUSIONS

In comparison with histidine-tryptophan-ketoglutarate solution, del Nido solution seems to have acceptable safety and efficacy with good myocardial protection in minimally invasive cardiac surgery. Further studies focusing on complex surgeries requiring longer cardiac ischemic time are needed.

Superior restoration of left ventricular performance after prolonged single-dose del Nido cardioplegia in conjunction with terminal warm blood cardioplegic reperfusion

OBJECTIVES

An incomplete restoration of left ventricular contractility after del Nido cardioplegia was noted in our recent study. This study tested the hypothesis that terminal warm blood cardioplegia promotes a prompt restoration of left ventricular performance after a prolonged single-dose del Nido cardioplegia.

METHODS

Fourteen piglets were subjected to 120 minutes of arrest by del Nido cardioplegia without terminal warm blood cardioplegia (del Nido cardioplegia group; n = 7) or with terminal warm blood cardioplegia before reperfusion (terminal warm blood cardioplegia group; n = 7). The other 7 piglets underwent total cardiopulmonary bypass without ischemia/reperfusion for 150 minutes (control group). Left ventricular function was assessed by percent recovery of end-systolic elastance as the contractility and percent end-diastolic pressure-volume relationship as the compliance using a conductance catheter. Troponin T and the mitochondrial score were also measured.

RESULTS

Depressed percent recovery of end-systolic elastance was sustained in the del Nido cardioplegia group, and a prompt restoration of end-systolic elastance was achieved using terminal warm blood cardioplegia (57.9 ± 17.8 vs 94.7 ± 13.1, P < .028). Percent end-diastolic pressure-volume relationship at the early phase was better in the terminal warm blood cardioplegia compared with the del Nido group (88.5 ± 24.0 vs 101.4 ± 16.8, P = .050). Troponin T was higher in the terminal warm blood cardioplegia compared with the control group (0.80% ± 0.21% and 1.49% ± 0.31%, respectively, P = .002). The mitochondrial score was equivalent in all groups. Spontaneous restoration to sinus rhythm was more frequent in the terminal warm blood cardioplegia group than in the del Nido cardioplegia group (6/7 vs 1/7, P < .028).

CONCLUSIONS

The supplementary use of terminal warm blood cardioplegia achieved prolongation of the safe ischemic time up to 120 minutes for a single-dose application.

Safety and Effectiveness of Del Nido Cardioplegia in Comparison to Blood-Based St. Thomas Cardioplegia in Congenital Heart Surgeries: A Prospective Randomized Controlled Study

Background:

To compare the safety and effectiveness of del Nido cardioplegia with blood-based St Thomas Hospital (BSTH) cardioplegia in myocardial protection in congenital heart surgery.

Methods:

It is a prospective, open-labeled, randomized controlled study conducted at National Heart Institute, Kuala Lumpur from July 2018 to July 2019. All patients with simple and complex congenital heart diseases (CHD) with good left ventricular function (left ventricular ejection fraction [LVEF] >50%) were included while those with LVEF <50% were excluded. A total of 100 patients were randomized into two groups of 50 each receiving either del Nido or BSTH cardioplegia. Primary end points were the spontaneous return of activity following aortic cross-clamp release and ventricular function between two groups. Secondary end point was myocardial injury as assessed by troponin T levels.

Results:

Cardiopulmonary bypass and aortic cross-clamp time, return of spontaneous cardiac activity following the aortic cross-clamp release, the duration of mechanical ventilation, and intensive care unit stay were comparable between two groups. Statistically significant difference was seen in the amount and number of cardioplegia doses delivered ( P < .001). The hemodilution was significantly less in the del Nido complex CHD group compared to BSTH cardioplegia ( P = .001) but no difference in blood usage ( P = .36). The myocardial injury was lesser (lower troponin T release) with del Nido compared to BSTH cardioplegia ( P = .6).

Conclusion:

Our study showed that both del Nido and BSTH cardioplegia are comparable in terms of myocardial protection. However, single, less frequent, and lesser volume of del Nido cardioplegia makes it more suitable for complex repair.

Serial ultrastructural evaluation of myocardial ischemic injury after infusion of del Nido cardioplegia in the human heart

OBJECTIVES

The safe ischemic time after a single-dose del Nido cardioplegia (DNC) infusion has not yet been established. This study evaluated the progression of myocardial ischemic injury to establish the safe ischemic time after a single-dose DNC infusion in the human heart using a transmission electron microscope.

METHODS

Seven hearts extracted from heart transplant recipients after infusion of 1000 mL single-dose DNC were evaluated. Serial left ventricular myocardial tissue samples were collected every 30 minutes for 180 minutes. Ischemic injuries in the mitochondria and nuclei were scored from 0 to 3 (0 = normal, 0.5 = slight, 1 = moderate, 2 = severe, and 3 = irreversible).

RESULTS

At the time of extraction, 83.5% of the mitochondria were normal. The proportion of mitochondria with moderate ischemic injury increased gradually from 1.4% at extraction to 52.5% at 180 minutes. From 90 minutes to 180 minutes, the proportion of mitochondria with severe and irreversible injury increased from 0.8% to 4.4% and 0.3% to 1.3%, respectively. A significant linear correlation was identified between the average ischemic injury score of mitochondria and ischemic time (P < .001). Most nuclei showed moderate to severe ischemic injury at every time point (61.0%-85.2%). A significant linear correlation was also found between the average ischemic injury score of nuclei and ischemic time (P < .001).

CONCLUSIONS

Myocardial ischemic injury progresses gradually, and irreversible ischemic injury begins to occur 90 minutes after initial DNC infusion in the adult human heart. Therefore, redosing of DNC may be required after 90 minutes of aortic crossclamp time during adult cardiac surgery.

Effect of single-dose crystalloid cardioplegic agent compared to bloody cardioplegic agent in cardiac surgery in children with Tetralogy of Fallot

BACKGROUND

Cardioplegia is one of the main post-operative cardiac protective factors widely used in recent decades in the form of crystalloid (St. Thomas) and bloody solutions [del Nido (DN)]. The purpose of this study was to compare the effect of a crystalloid cardioplegic agent (St. Thomas) with that of a bloody cardioplegic agent (DN) in pediatric cardiac surgery among children with Tetralogy of Fallot (TOF).

METHODS

This study was performed on 60 children with TOF, who were candidates for heart repair surgery. The participants were randomly divided into two groups of crystalloid cardioplegic agent and bloody cardioplegic agent. Operative outcomes such as required time for onset of heart arrest, duration of returning to normal heart rhythm, and cardiopulmonary bypass (CPB) time, and operative complications were compared between the two groups.

RESULTS

The duration of returning to normal heart rhythm (50.43 ± 10.93 seconds vs. 43.03 ± 16.35 seconds; P = 0.044) and duration of inotropy (80.40 ± 27.14 hours vs. 63.20 ± 26.91 hours; P = 0.017) were significantly higher in the DN group compared to the St. Thomas group. However, there were no significant differences between the two groups in terms of heart arrest time, cross-clamp time, CPB time, supplementary lasix time, duration of intubation, and intensive care unit (ICU) and hospital length of stay (LOS) (P > 0.050).

CONCLUSION

The use of St. Thomas cardioplegic solution was more effective in reducing the duration of returning to normal heart rhythm and inotropy compared with DN cardioplegic agent, and a single dose of these two cardioplegic agents can keep the mean cardiac arrest duration within the range of 50-70 minutes. It seems that the use of St. Thomas cardioplegic solution can be suggested in pediatric heart surgery.

Quality Improvement in Congenital Heart Surgery

Congenital heart disease is a major public health concern in the United States. Outcomes of surgery for children with congenital heart disease have dramatically improved over the last several decades with current aggregate operative mortality rates approximating 3%, inclusive of all ages and defects. However, there remains significant variability among institutions, especially for higher-risk and more complex patients. As health care moves toward the quadruple aim of improving patient experience, improving the health of populations, lowering costs, and increasing satisfaction among providers, congenital heart surgery programs must evolve to meet the growing scrutiny, demands, and expectations of numerous stakeholders. Improved outcomes and reduced interinstitutional variability are achieved through prioritization of quality assurance and improvement.

Myocardial protection in the arterial switch operation: Custodiol versus cold blood cardioplegia

OBJECTIVES

The optimal myocardial protective solution in the neonatal arterial switch operation remains controversial. The aim of this study was to demonstrate that Bretschneider's histidine-tryptophan-ketoglutarate crystalloid solution (Custodiol) offers protection at least similar to that of cold blood cardioplegia.

METHODS

Patients who underwent the neonatal arterial switch operation with Custodiol between January 2016 and December 2018 (n = 23) were compared with an historical cohort from August 2010 to December 2015 in which cold blood cardioplegia was used (n = 41). A linear mixed-effect model for repeated measures was performed to test the recovery of myocardial function based on inotropic and vasoactive inotropic scores, cardiac enzyme release and left ventricular ejection fraction.

RESULTS

Patients in the cold blood cardioplegia group had higher inotropic scores in the first 24 h (0 h, P = 0.001 and 24 h, P = 0.006) and higher vasoactive inotropic scores in the first 72 h (0 h, 24 h and 48 h, P < 0.001; 72 h, P = 0.012). Cardiac troponin-I concentrations were higher in the cold blood cardioplegia group at postoperative hours 1-72 (1 h, 6 h, 12 h and 24 h, P < 0.001; 48 h, P = 0.001 and 72 h, P = 0.003). Creatinine-kinase-MB concentrations were higher in the cold blood cardioplegia group at postoperative hours 1-24 (1 h, 6 h and 12 h, P < 0.001; 24 h, P = 0.042). The left ventricular ejection fraction was higher in the Custodiol group just after the operation (P = 0.005), at 24 h (P = 0.001) and on the first day without inotropic support (P = 0.011).

CONCLUSIONS

Neonatal myocardium protected with Custodiol during the arterial switch operation presented optimal ventricular function recovery with less inotropic support and less myocardial damage compared with cold blood cardioplegia.

Custodiol cardioplegia solution compared to cold blood cardioplegia in pediatric cardiac surgery: a single-institution experience

OBJECTIVE

Custodiol is an intracellular, crystalloid cardioplegia solution that is a single-dose alternative to multi-dose cold blood cardioplegia; however, there is scarce data regarding its use in infants and children. The objective of this study was to compare its impact on myocardial function in infants.

METHODS

Single-center retrospective review including 132 patients <12 months old undergoing biventricular repair. There were 106 patients who received single-dose Custodiol and 27 patients who received multi-dose blood cardioplegia. Demographic and echocardiographic data were compared between the two groups.

RESULTS

Patients receiving Custodiol were slightly younger (100 ± 62 days) and lower weight (4.7 ± 1.3 kg) compared to 152 ± 86 days and 5.2 ± 1.3 kg for blood cardioplegia (p < 0.05). The Society of Thoracic Surgeons/European Association for Cardio-Thoracic Surgery Congenital Heart Surgery score was similar between both groups. Average cardiopulmonary bypass time was similar between both groups (Custodiol 93 ± 54 minutes vs. blood 81 ± 44 minutes, p = 0.46) as was aortic cross-clamp time (Custodiol 58 ± 33 minutes vs. cold blood 53 ± 33 minutes, p = 0.62). Pre-operative left ventricular ejection fraction was similar for blood 73 ± 8% versus Custodiol 70 ± 9%, p = 0.21. There was also no intergroup difference in left ventricular ejection fraction 24 hours post op (blood 64 ± 9% vs. Custodiol 65 ± 12%, p = 0.53) or at discharge (blood 66 ± 10% vs. Custodiol 66 ± 11%, p = 0.95). The pre-operative right ventricle function by fractional area change was also similar in blood cardioplegia (46 ± 13%) versus Custodiol (48 ± 9%, p = 0.38) and showed similar drops in parameters in the two groups 24 hours after surgery and at discharge.

CONCLUSION

Single-dose Custodiol is as safe as blood cardioplegia for myocardial protection in congenital cardiac surgery for the cross-clamp times evaluated in this study. Evaluation at longer cross-clamp times would be helpful to determine if there is a greater benefit to single-dose Custodiol versus more repeated doses of blood cardioplegia for longer cross-clamp times.

Single-Shot Cold Histidine-Tryptophan-Ketoglutarate Cardioplegia for Long Aortic Cross-Clamping Durations in Neonates

OBJECTIVE

More than 30% of European pediatric cardiac surgery centers use single-dose cold histidine-tryptophan-ketoglutarate cardioplegia (Custodiol; Dr Franz Köhler Chemie GmbH, Bensheim, Germany). In neonates with transposition of the great arteries, arterial switch surgery (ASO) implies aortic division, and it is unknown whether repeated ostial cannulation causes intimal insult and affects long-term results, and therefore, single-dose Custodiol is appealing. The present study investigated the association among myocardial no-flow duration, postoperative troponins, and postoperative outcomes in neonates undergoing ASO with Custodiol cardioplegia.

DESIGN

Retrospective analysis of the association among myocardial no-flow duration, postoperative troponin release (concentration magnitude × measurement duration within 48 h), and outcomes using stratification according to coronary anatomy and attending surgeon.

SETTING

Single-institutional, tertiary pediatric cardiac surgery unit of a university hospital.

PARTICIPANTS

The study comprised 101 neonates undergoing ASO.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The mean age of patients was 6.1 ± 5.4 days, the cardiopulmonary bypass duration was 108.7 ± 54.1 minutes, the temperature during cross-clamping was 31.1°C ± 1.7°C, the duration of mechanical ventilation was 4 (3-6) days, the length of intensive care unit stay was 7 (5-8) days, delayed sternal closure occurred in 32 (31.7%) patients, and no patients died. The myocardial no-flow duration averaged 62.3 ± 14.6 minutes and was linked with both troponin release (p = 0.04) and low cardiac output syndrome, as assessed by the requirement for delayed sternal closure (p = 0.03), regardless of cardiopulmonary bypass duration and temperature. Eighty-two percent of the patients with myocardial no-flow duration >74 minutes necessitated delayed sternal closure.

CONCLUSIONS

Single-dose Custodiol may be inadequate for prolonged cross-clamping durations without myocardial perfusion in neonates.

Excellent Restoration of Left Ventricular Compliance After Prolonged Del Nido Single-Dose Cardioplegia in an In Vivo Piglet Model

Del Nido cardioplegia (DN) is used in congenital heart surgery and recently in adults, a single dose has been administered. However, the tolerable ischemic time has not been established. The objective is to evaluate the left ventricular (LV) function recovery and accompanying biochemical and histologic markers to clarify the tolerable ischemic time in an in vivo cardiopulmonary bypass (CPB) piglet model. Twenty-one piglets were subjected to either 90 minutes (with or without topical cooling; TC) or 120 minutes (with TC) of global ischemia induced by single-dose DN, while the other 7 served as the control group (CPB only). The CPB temperature was established with a perfusion temperature of 30°C. The LV function recovery was assessed by the percent change in end-systolic elastance (Ees) and the end-diastolic pressure-volume relationship (EDPVR). Creatine kinase-MB (CK-MB) levels and the mitochondrial score were also assessed. LV contractility assessed by %Ees after 90 and 120 minutes of ischemia (89.3 ± 20.6% and 57.9 ± 17.8%) was lower compared with the control group (122.6 ± 35.8%, P = 0.001). Conversely, LV compliance assessed by %EDPVR was preserved in both groups (102.7 ± 28.2% and 88.5 ± 24.0%), which was comparable to the control group (105.8 ± 36.9%, P = 0.531). There was no change in LV contractility after 90 minutes of ischemia with or without TC (89.3 ± 20.6% or 84.8 ± 16.2%, P = 0.657), whereas LV compliance was lower but not statistically different without TC (102.7 ± 28.2% vs 78.0 ± 38.9%). CK-MB and the mitochondrial score were equivalent between all groups. The proposed single-dose ischemic time for redosing is 90 minutes using TC.

A Systematic Review and Meta-Analysis of del Nido Versus Conventional Cardioplegia in Adult Cardiac Surgery

OBJECTIVE

Del Nido cardioplegia (DC) has been used extensively in pediatric cardiac surgery but the efficacy and safety in adults remains uncertain. Our objective was to perform a systematic review and meta-analysis comparing DC and blood cardioplegia (BC) in our primary endpoint of 30-day or in-hospital mortality as well as other efficacy and safety endpoints.

METHODS

Both MEDLINE and EMBASE were searched from 1996 to 2017 for studies comparing DC and BC. Data were extracted by 2 independent investigators and aggregated in a random effects model.

RESULTS

One randomized controlled trial (n = 89), 7 adjusted (n = 1,104), and 5 unadjusted observational studies (n = 717) were included. There was no difference in in-hospital mortality between DC and BC (relative risk:0.67, 95% confidence interval [CI]: 0.22, 2.07; P = 0.49). DC reduced cardioplegia volume requirements (mean difference [MD]:-1.1 L, 95% CI, -1.6, -0.6; P < 0.0001), aortic cross-clamp time (MD: -8 minutes, 95% CI, -12, -3; P = 0.0004), and cardiopulmonary bypass (CPB) times (MD: -8 minutes, 95% CI, -14, -3; P = 0.03). DC reduced troponin release (standardized MD: -0.3, 95% CI, -0.5, -0.1; P = 0.001). In-hospital outcomes of stroke, atrial fibrillation, acute kidney injury/dialysis, low cardiac output state, blood transfusion, reoperation rate, postoperative left ventricular EF, intensive care unit length of stay (LOS), and in-hospital LOS were comparable between groups.

CONCLUSIONS

DC is a safe alternative to BC in routine adult cardiac surgery. Its use is associated with reduction in CPB and aortic cross-clamp times and may potentially offer improved myocardial protection.

Single-center experience with the combination of Cardioplexol™ cardioplegia and MiECC for isolated coronary artery bypass graft procedures

Background

Cardioplexol™ with its low volume (100 mL) was originally conceived as cardioplegic solution for MiECC procedures. Introduced in its current form in 2008 in our clinic, it has immediately demonstrated attractive advantages including the easy and rapid administration by the surgeon him/herself, the almost immediate cardiac arrest and a prolonged delay before a second dose is necessary. We report here the results of our initial experience with this simple solution.

Methods

Single centre, retrospective observational analysis of prospectively collected data of isolated coronary artery bypass graft (CABG) procedures performed with a MiECC.

Results

Of 7,447 adult cardiac surgical operations performed during a 76 months period, 2,416 were isolated CABG-MiECC procedures. Patients were 81.3% males, 66.2±9.7 years old and had a median logistic EuroSCORE of 3.2. In average 3.2±0.8 vessels were bypassed. Median cross-clamp time was 45 minutes and more than 75% of the patients received only one 100 mL dose of Cardioplexol™. At reperfusion more than 90% of the hearts spontaneously recovered a rhythmic activity. Maximal value of troponin T during the first hours following myocardial reperfusion was 0.9±4.5 ng/mL (median =0.4 ng/mL). Mortality at 30 days was 0.9%.

Conclusions

Cardioplexol™ seems very promising. It appears especially efficient and safe when used for CABG procedures performed with a MiECC.

The del Nido versus cold blood cardioplegia in aortic valve replacement: A randomized trial

OBJECTIVES

To compare the cardioprotective efficacy of a solution that requires only a single infusion at the start of the ischemic duration versus a solution that requires multiple infusions.

METHODS

Aortic valve replacement was performed for 150 patients, who were randomized into the del Nido (DN) cardioplegia group or the cold blood (CB) cardioplegia group. The DN cardioplegia was delivered every 90 minutes and the CB cardioplegia was delivered every 20 to 30 minutes, or whenever cardiac activity was observed. The primary endpoints were electrical cardiac activity during crossclamp, ventricular fibrillation during reperfusion, and postoperative troponin and creatine kinase (CK-MB isoenzyme) at 24 and 48 hours.

RESULTS

Electrical activity during crossclamp occurred in 29 (39.7%) patients in the DN group versus 34 (45.3%) patients in the CB group (adjusted P = 1.0). The number of procedures with ventricular fibrillation after removing the crossclamp was 41 (54.7%) in the CB group versus 17 (22.7%) in the DN group (adjusted P = .001; relative risk, 2.41). Troponin values appeared to be lower in the DN group (median, 223.10; interquartile range, 168.35-364.77 pg/mL vs 285.5; 196.20-419.45 pg/mL at 24 hours and 159.60; 125.42-217.20 pg/mL vs 201.60; 160.62-268.45 pg/mL at 48 hours) and CK-MB (median, 14.94; interquartile range, 12.16-20.39 ng/mL vs 17.43; 13.66-22.43 ng/mL at 24 hours and 6.19; 4.41-7.63 ng/mL vs 7.38; 4.74-10.20 ng/mL at 48 hours), but no significance was found.

CONCLUSIONS

The del Nido cardioplegia protocol is an acceptable alternative for cold blood cardioplegia in patients undergoing aortic valve replacement.

Recent achievements and future developments in neonatal cardiopulmonary bypass

A primary goal of improving neonatal cardiopulmonary bypass has been making the circuit smaller and reduce the blood contacting surfaces. As bypass circuit size has decreased, bloodless surgery has become possible even in neonates. Since transfusion guidelines are difficult to construct based on existing literature, these technical advances should be taken advantage of in conjunction with an individualized transfusion scheme, based on monitoring of oxygen availability to the tissues. For the majority of neonatal heart operations, several centers have shifted toward normothermic bypass even for complex neonatal surgeries, in order to avoid the adverse effects of hypothermia. Deep hypothermic circulatory arrest is no longer a necessity but an option, and selective antegrade cerebral perfusion has become common practice; however, technical uncertainties with regard to this technique have to be addressed, based on reliable neurologic monitoring. Maintenance of patient-specific heparin concentrations during bypass is another key goal, since neonates have lower baseline antithrombin concentrations and, therefore, a higher risk for inadequate thrombin inhibition and postoperative bleeding. Due to the immaturity of their hemostatic system, the standard coagulation tests alone are inappropriate to guide hemostatic therapy in neonates. The use of indirect heparin concentration assays and global viscoelastic assays in the operating room is likely to represent the optimal strategy, and requires validation in neonates. Monitoring of global and regional indexes of oxygen availability and consumption on bypass have become possible; however, their use in neonates still has outstanding technical issues which should be addressed and hence needs further validation. Due to the immaturity of the neonatal myocardium, single-shot cold cardioplegia solutions are thought to confer the best myocardial protection; their superiority when compared to more conventional modalities, however, remains to be demonstrated.

Safe cross-clamp time using Custodiol®-histidine-tryptophan-ketoglutarate cardioplegia in the adult

INTRODUCTION

Safe cross-clamp time using single-dose Custodiol^®-histidine-tryptophan-ketoglutarate cardioplegia has not been established conclusively.

METHODS

Immediate post-operative outcomes of 1,420 non-consecutive, cardiac surgery patients were reviewed retrospectively. Predictors of a combined endpoint made of in-hospital mortality and any major complication post-surgery were found with the multivariable method. Analysis of variance was used to evaluate the impact of cross-clamp time on most relevant complications. Discriminatory power and cut-off value of cross-clamp time were established for in-hospital mortality and each of the major complications (receiver operating characteristic curve analysis). A comparative analysis (with propensity matching) with multidose cold blood cardioplegia on in-hospital mortality post-surgery was performed in non-coronary surgery patients.

RESULTS

Coronary, aortic valve and mitral valve surgery and surgery on thoracic aorta were performed in 45.4%, 41.9%, 49.5%, 20.6% of cases, respectively. In-hospital mortality and the rate of any major complication post-surgery were 6.5% and 41.9%, respectively. Cross-clamp time had significant impact on in-hospital mortality and almost all major post-operative complications, except neurological dysfunctions (p = 0.084), myocardial infarction (p = 0.12) and mesenteric ischaemia (p = 0.85). Areas under the receiver operating characteristic curve and the optimal cut-off values for in-hospital mortality and any major complication were of 0.657, 0.594, >140 and >127 minutes, respectively. Comorbidities-adjusted odds ratio for any major complication of cross-clamp time <127 minutes was 1.86 (p < 0.0001). Despite similar in-hospital mortality (p = 0.57), there was an earlier significant increase of mortality in Custodiol-HTK than in multidose cold blood propensity-matched, non-coronary surgery patients.

CONCLUSIONS

The use of Custodiol-HTK cardioplegia is associated with a low risk of serious post-operative complications provided that cross-clamp time is of 2 hours or less.

Cardioplegia in paediatric cardiac surgery: a systematic review of randomized controlled trials

OBJECTIVES

Cardioplegia is the primary method for myocardial protection during cardiac surgery. We conducted a systematic review of randomized controlled trials of cardioplegia in children to evaluate the current evidence base.

METHODS

We searched MEDLINE, CENTRAL and LILACS and manually screened retrieved references and systematic reviews to identify all randomized controlled trials comparing cardioplegia solutions or additives in children undergoing cardiac surgery published in any language; secondary publications and those reporting inseparable adult data were excluded. Two or more reviewers independently screened studies for eligibility and extracted data; the Cochrane Risk of Bias tool was used to assess for potential biases.

RESULTS

We identified 26 trials randomizing 1596 children undergoing surgery; all were single-centre, Phase II trials, recruiting few patients (median 48, interquartile range 30-99). The most frequent comparison was blood versus crystalloid in 10 (38.5%) trials, and the most common end points were biomarkers of myocardial injury (17, 65.4%), inotrope requirements (15, 57.7%) and length of stay in the intensive care unit (11, 42.3%). However, the heterogeneity of patients, interventions and reported outcome measures prohibited meta-analysis. Overall risk of bias was high in 3 (11.5%) trials, unclear in 23 (88.5%) and low in none.

CONCLUSIONS

The current literature on cardioplegia in children contains no late phase trials. The small size, inconsistent use of end points and low quality of reported trials provide a limited evidence base to inform practice. A core outcome set of clinically important, standardized, validated end points for assessing myocardial protection in children should be developed to facilitate the conduct of high-quality, multicentre trials.

PROSPERO registration

CRD42017080205.

Clampless cardioplegia: an alternative to conventional cardioplegia administration

Myocardial protection is of the utmost importance during cardiac surgery. At times, there are patients who present to the operating room who make the typical use of cardioplegia difficult or impossible. For these patients, a separate protocol and process must be in place. "Clampless cardioplegia" is an option when the ascending aorta cannot be cross-clamped, but the surgeon needs a bloodless field with a quiescent heart. This study reports on the process of developing a policy and protocol for utilizing clampless or systemic cardioplegia. Four case reports of patients who received clampless or systemic cardioplegia and their peri-operative courses are described. These four patients showed no cardiac functional change by post-operative echocardiogram and no peri-operative complications are reported.

A Review of Goal-Directed Cardiopulmonary Bypass Management in Pediatric Cardiac Surgery

Cardiopulmonary bypass perfusion management significantly affects postoperative outcomes. In recent years, the principles of goal-directed therapy have been applied to the field of cardiothoracic surgery to improve patient outcomes. Goal-directed therapy involves continuous peri- and postoperative monitoring of vital clinical parameters to tailor perfusion to each patient's specific needs. Closely measured parameters include fibrinogen, platelet count, lactate, venous oxygen saturation, central venous oxygen saturation, mean arterial pressure, perfusion flow rate, and perfusion pulsatility. These parameters have been shown to influence postoperative fresh frozen plasma transfusion rate, coagulation state, end-organ perfusion, and mortality. In this review, we discuss the recent paradigm shift in pediatric perfusion management toward goal-directed perfusion.

Normothermic versus hypothermic cardiopulmonary bypass in low-risk paediatric heart surgery: a randomised controlled trial

OBJECTIVE

To compare normothermic (35°C-36°C) versus hypothermic (28°C) cardiopulmonary bypass (CPB) in paediatric patients undergoing open heart surgery to test the hypothesis that normothermic CPB perfusion maintains the functional integrity of major organ systems leading to faster recovery.

METHODS

Two single-centre, randomised controlled trials (known as Thermic-1 and Thermic-2, respectively) were carried out to compare the effectiveness and acceptability of normothermic versus hypothermic CPB in children with congenital heart disease undergoing open heart surgery. In both studies, the co-primary clinical outcomes were duration of inotropic support, intubation time and postoperative hospital stay.

RESULTS

In total, 200 participants were recruited; 59 to the Thermic-1 study and 141 to the Thermic-2 study. 98 patients received normothermic CPB and 102 patients received hypothermic CPB. There were no significant differences between the treatment groups for any of the co-primary outcomes: inotrope duration HR=1.01, 95% CI (0.72 to 1.41); intubation time HR=1.14, 95% CI (0.86 to 1.51); postoperative hospital stay HR=1.06, 95% CI (0.80 to 1.40). Differences favouring normothermia were found in urea nitrogen at 2 days geometric mean ratio (GMR)=0.86 95% CI (0.77 to 0.97); serum creatinine at 3 days GMR=0.89, 95% CI (0.81 to 0.98); urinary albumin at 48 hours GMR=0.32, 95% CI (0.14 to 0.74) and neutrophil gelatinase-associated lipocalin at 4 hours GMR=0.47, 95% CI (0.22 to 1.02), but not at other postoperative time points.

CONCLUSIONS

Normothermic CPB is as safe and effective as hypothermic CPB and can be routinely adopted as a perfusion strategy in low-risk infants and children undergoing open heart surgery.

TRIAL REGISTRATION NUMBER

ISRCTN93129502.

Cardioplegia practice in paediatric cardiac surgery: a UK & Ireland survey

Introduction:

Many techniques are available for cardioplegic arrest in children, but there is a lack of late phase clinical trials to guide practice. We surveyed paediatric cardiac surgeons and perfusionists to establish current practice and willingness to change within a clinical trial.

Methods:

An online survey was sent to all consultant paediatric cardiac surgeons and chief perfusionists in paediatric centres in the UK and Ireland. Information was sought on cardioplegia type, composition, temperature, topical cooling, dosing for induction and maintenance, interval between doses, whether practice changed with patient age or complexity and whether respondents would be willing and able to use different cardioplegia solutions within a randomised trial.

Results:

Responses were obtained from 32 (78.0%) surgeons and 12 (100%) perfusionists. Twenty-seven (84.4%) surgeons use blood cardioplegia in infants, with St. Thomas’ Harefield preparation the most popular (19, 59.4%), used routinely in eight (66.7%) centres. Twenty-two (68.8%) administer at 4-6°C, 18 (56.3%) use topical cooling, 18 (56.3%) give 30 ml/kg induction and 15 ml/kg maintenance, with 23 (71.9%) re-dosing every 20-25 minutes. Thirty (93.8%) surgeons were open to randomising patients in a trial, with del Nido (29, 90.6%) the most popular.

Conclusions:

This survey demonstrates heterogeneity in cardioplegia practice. Whilst most surgeons use blood cardioplegia, there is variation in type, temperature, topical cooling, dosing and intervals. Combined with a lack of evidence from late phase trials, our findings support the presence of clinical equipoise. Surgeons are willing to change practice, suggesting that a pragmatic, multi-centre, randomised, controlled trial of cardioplegia in children is feasible.

Type of cardioplegic solution as a factor influencing the clinical outcome of open-heart congenital procedures

Introduction

Cardioplegia is one of the most important modalities of myocardial protection during heart surgery.

Aim

To assess the impact of blood cardioplegia on postoperative variables, in comparison with two types of crystalloid cardioplegic solutions during pediatric heart surgery.

Material and methods

One thousand one hundred and twenty-nine patients underwent surgical correction of congenital heart disease with cardioplegia administration between 2006 and 2012. Nonlinear regression models of postoperative low cardiac output syndrome (LCOS) incidence, catecholamine index and total complication count were developed using a genetic algorithm. The Akaike information criterion was applied for selection of the best model. The following explanatory variables were evaluated: cardioplegia type (ST - Saint Thomas, n = 440; FR - Fresenius, n = 432; BL - Calafiore, n = 257), congenital heart diseases (CHD) type, age, sex, genetic disorder presence, body surface area (BSA), cardiopulmonary bypass (CBP) time, aortic cross-clamp time, operation urgency, redo surgery, surgeon.

Results

Low cardiac output syndrome presence and higher than average catecholamine indexes were negatively influenced by use of crystalloid cardioplegia (ST or FR), presence of specific CHDs, redo surgery and prolonged CBP time. Increased complication count was related to: crystalloid cardioplegia, presence of specific CHDs, redo surgery, urgency of operation, operation time and CBP time. Higher BSA had a protective effect against higher catecholamine index and increased complication count. Older age was protective against LCOS.

Conclusions

Cardioplegic solutions type influences postoperative variables in children after heart surgery by the negative impact of crystalloid cardioplegia. Blood cardioplegia presents potential advantages for patients - its application may reduce the incidence of low cardiac output syndrome and related complications.

The Norwood Stage 1 procedure - conduct of perfusion: 2017 Survey results from NPC-QIC member institutions

Hypoplastic left heart syndrome (HLHS) is a rare and severe congenital cardiac defect. Approximately 1000 infants are born with HLHS in the United States every year. Healthcare collaboratives over the last decade have focused on sharing patient experiences and techniques in an effort to improve outcomes. In 2010, cardiologists and patient families joined together to improve the care of HLHS patients by forming the National Pediatric Cardiology Quality Improvement Collaborative (NPC-QIC). Sixty-six of the approximately 110 institutions caring for patients with HLHS in the United States and Canada are now members of NPC-QIC. In 2017, cardiovascular perfusionists joined the collaborative as another specialty involved in the care of HLHS patients. Perfusionists and cardiac surgeons developed the collaborative’s first conduct of perfusion survey for the Norwood Stage 1 procedure, specifically targeting the provision of cardiopulmonary bypass for patients with HLHS. This manuscript discusses the results of this survey, unveiling a significant variance in the conduct of perfusion for this patient population.

Comparison of del Nido Cardioplegia With Blood Cardioplegia in Adult Combined Surgery

OBJECTIVE

del Nido solution (DNS) is a single-dose cardioplegia designed for pediatric use proposed to offer superior myocardial protection in adults. However, few data support this claim. We hypothesized that DNS and modified blood cardioplegia solution (BS) provide equivalent safety in combined adult valve surgery.

METHODS

Between November 2014 and December 2015, 25 patients underwent primary aortic valve replacement and concomitant coronary artery bypass grafting (CABG) with DNS. Outcomes were compared with 25 patients who underwent the same surgery with BS between September 2013 and August 2015.

RESULTS

All preoperative characteristics, comorbidities, and number of CABG performed were similar between groups. One hospital death occurred in the BS group. Postoperative creatine kinase, MB isotype (16.7 ± 5.3 μg/L vs. 22.1 ± 8.9 μg/L, P = 0.011) and troponin T levels (260 ± 105.3 ng/L vs. 370.5 ± 218.4 ng/L, P = 0.028) were significantly lower in the DNS group. There was no difference in inotropic or vasoactive agent use (P = 0.512). Cardiopulmonary bypass times (65.5 ± 12.5 min vs. 76.6 ± 19.1 min, P = 0.019) and cross-clamp times (55.6 ± 11.2 min vs. 64.3 ± 18.9 min, P = 0.05) were lower in the DNS group but total operating room times (P = 0.198) were similar. Peak postoperative creatinine levels were similar in both groups (P = 0.063). There was no difference in postoperative outcomes including acute renal failure (P > 0.999), atrial fibrillation (P = 0.773), acute respiratory failure (P > 0.999), nor stroke or transient ischemic attack (P > 0.999). Intensive care unit stay (P = 0.213) and hospital stay (P = 0.1) did not differ between groups.

CONCLUSIONS

The DNS can be used as an alternative to BS in adult concomitant aortic valve replacement + CABG surgery. This supports our hypothesis that in this specific setting, DNS provides comparable myocardial protection as BS, with possibly shorter cardiopulmonary bypass and cross-clamp times.