Effect of Dexmedetomidine on Incidence of Hypertension Following Repair of Coarctation of the Aorta.

OBJECTIVE: Recent literature suggests a potential role for dexmedetomidine in reducing the incidence and severity of hypertension following repair of coarctation of the aorta (CoA). The primary aim of this study was to assess the association between dexmedetomidine use and the incidence of hypertension following repair of CoA in pediatric patients. METHODS: This was a single-center, retrospective cohort study in patients younger than 19 years who underwent surgical repair of CoA between January 1, 2016, and September 30, 2021. Patients were divided into 2 groups: dexmedetomidine initiation within the first 3 hours after surgery or no dexmedetomidine. The primary outcome was incidence of hypertension within the first 4 to 24 hours after repair. Secondary outcomes included the incidence of hypotension and bradycardia. RESULTS: A total of 80 patients were included, 25 (31.25%) received dexmedetomidine. Median age at the time of procedure was 26 days (IQR, 13-241) in the dexmedetomidine group and 14 days (IQR, 8-53) in the no dexmedetomidine group (p = 0.014). The primary outcome of hypertension was met in 7 patients (28%) in the dexmedetomidine group and 12 patients (21.8%) in the no dexmedetomidine group, p = 0.547. The only variable found to be associated with the incidence of hypertension was age greater than 30 days at the time of procedure. More patients who received dexmedetomidine experienced bradycardia. There was no difference in the incidence of hypotension. CONCLUSIONS: There was no association between the use of dexmedetomidine and the incidence of -hypertension following repair of CoA in pediatric patients.

Chronic Medication Burden After Cardiac Surgery for Pediatric Medicaid Beneficiaries.

BACKGROUND: Congenital heart defects are the most common and resource-intensive birth defects. As children with congenital heart defects increasingly survive beyond early childhood, it is imperative to understand longitudinal disease burden. OBJECTIVES: The purpose of this study was to examine chronic outpatient prescription medication use and expenditures for New York State pediatric Medicaid enrollees, comparing children who undergo cardiac surgery (cardiac enrollees) and the general pediatric population. METHODS: This was a retrospective cohort study of all Medicaid enrollees age <18 years using the New York State Congenital Heart Surgery Collaborative for Longitudinal Outcomes and Utilization of Resources database (2006-2019). Primary outcomes were total chronic medications per person-year, enrollees per 100 person-years using ≥1 and ≥3 medications, and medication expenditures per person-year. We described and compared outcomes between cardiac enrollees and the general pediatric population. Among cardiac enrollees, multivariable regression examined associations between outcomes and clinical characteristics. RESULTS: We included 5,459 unique children (32,131 person-years) who underwent cardiac surgery and 4.5 million children (22 million person-years) who did not. More than 4 in 10 children who underwent cardiac surgery used ≥1 chronic medication compared with approximately 1 in 10 children who did not have cardiac surgery. Medication expenditures were 10 times higher per person-year for cardiac compared with noncardiac enrollees. Among cardiac enrollees, disease severity was associated with chronic medication use; use was highest among infants; however, nearly one-half of adolescents used ≥1 chronic medication. CONCLUSIONS: Children who undergo cardiac surgery experience high medication burden that persists throughout childhood. Understanding chronic medication use can inform clinicians (both pediatricians and subspecialists) and policymakers, and ultimately the value of care for this medically complex population.

Long-Term Health Care Utilization After Cardiac Surgery in Children Covered Under Medicaid.

BACKGROUND: Understanding the longitudinal burden of health care expenditures and utilization after pediatric cardiac surgery is needed to counsel families, improve care, and reduce outcome inequities. OBJECTIVES: The purpose of this study was to describe and identify predictors of health care expenditures and utilization for Medicaid-insured pediatric cardiac surgical patients. METHODS: All Medicaid enrolled children age <18 years undergoing cardiac surgery in the New York State CHS-COLOUR database, from 2006 to 2019, were followed in Medicaid claims data through 2019. A matched cohort of children without cardiac surgical disease was identified as comparators. Expenditures and inpatient, primary care, subspecialist, and emergency department utilization were modeled using log-linear and Poisson regression models to assess associations between patient characteristics and outcomes. RESULTS: In 5,241 New York Medicaid-enrolled children, longitudinal health care expenditures and utilization for cardiac surgical patients exceeded noncardiac surgical comparators (cardiac surgical children: $15,500 ± $62,000 per month in year 1 and $1,600 ± $9,100 per month in year 5 vs noncardiac surgical children: $700 ± $6,600 per month in year 1 and $300 ± $2,200 per month in year 5). Children after cardiac surgery spent 52.9 days in hospitals and doctors' offices in the first postoperative year and 90.5 days over 5 years. Being Hispanic, compared with non-Hispanic White, was associated with having more emergency department visits, inpatient admissions, and subspecialist visits in years 2 to 5, but fewer primary care visits and greater 5-year mortality. CONCLUSIONS: Children after cardiac surgery have significant longitudinal health care needs, even among those with less severe cardiac disease. Health care utilization differed by race/ethnicity, although mechanisms driving disparities should be investigated further.

Intravenous Dabigatran Provides Adequate Anticoagulation for Cardiopulmonary Bypass Using a Rabbit Model.

BACKGROUND: Heparin anticoagulation has been used successfully for cardiopulmonary bypass (CPB). However, an alternative anticoagulant approach is desirable due to the cases of heparin-induced thrombocytopenia. Dabigatran provides anticoagulation for an in vitro model of simulated CPB. The current analysis tests the hypothesis that dabigatran provides sufficient anticoagulation for CPB in intact rabbits. METHODS: Nonlinear mixed effects models were used to estimate dabigatran parameters for a two-compartment pharmacokinetic model in 10 New Zealand White rabbits. A dabigatran infusion designed to maintain a plasma concentration of 90 µg/ml was run throughout CPB based on the pharmacokinetics. Animals were subjected to sternotomy and anticoagulated with IV dabigatran (six animals) or heparin (four animals). Rabbits were cannulated centrally using the right atrium and ascending aorta and CPB was maintained for 120 min. Measurement of activated clotting time, thromboelastometric reaction time, and blood gases were performed during CPB. Then, the animals were euthanized, and the brain and one kidney were removed for histology. Sections of the arterial filters were inspected using electron microscopy. RESULTS: The observed dabigatran concentrations during CPB were greater than the target concentration, ranging from 137 ± 40 µg/ml at 5 min of CPB to 428 ± 150 µg/ml at 60 min, and 295 ± 35 µg/ml at 120 min. All rabbits completed 2 h of CPB without visible thrombosis. In the two groups, reaction time values were elevated, reaching 10,262 ± 4,198 s (dabigatran group) and 354 ± 141 s (heparin group) at 120 min of CPB. Brains and kidneys showed no evidence of thrombosis or ultrastructural damage. Sections of the arterial line filter showed minimal or no fibrin. There was no significant difference in outcomes between dabigatran- and heparin-treated animals. CONCLUSIONS: In this first-use, proof-of-concept study, the authors have shown that dabigatran provides acceptable anticoagulation similar to heparin to prevent thrombosis using a rabbit CPB model.

Using Serum Cystatin C to Predict Acute Kidney Injury Following Infant Cardiac Surgery.

Acute kidney injury (AKI) following cardiopulmonary bypass (CPB) is associated with increased morbidity and mortality. Serum Cystatin C (CysC) is a novel biomarker synthesized by all nucleated cells that may act as an early indicator of AKI following infant CPB. Prospective observational study of infants (< 1 year) requiring CPB during cardiac surgery. CysC was measured at baseline and 12, 24, 48, and 72 h following CPB initiation. Each post-op percent difference in CysC (e.g. %CysC12h) from baseline was calculated. Clinical variables along with urine output (UOP) and serum creatinine (SCr) were followed. Subjects were divided into two groups: AKI and non-AKI based upon the Kidney Disease Improving Global Outcomes (KDIGO) classification. AKI occurred in 41.9% (18) of the 43 infants enrolled. Patient demographics and baseline CysC levels were similar between groups. CysC levels were 0.97 ± 0.28 mg/L over the study period, and directly correlated with SCr (R = 0.71, p < 0.0001). Although absolute CysC levels were not significant between groups, the %CysC12h was significantly greater in the AKI group (AKI: - 16% ± 22% vs. Non-AKI - 28% ± 9% mg/L; p = 0.003). However, multivariate analysis demonstrated that a lower UOP (Odds Ratio:0.298; 95% CI 0.073, 0.850; p = 0.02) but not %CysC12h was independently associated with AKI. Despite a significant difference in the %CysC12h, only UOP was independently associated with AKI. Larger studies of a more homogenous population are needed to understand these results and to explore the variability in this biomarker seen across institutions.

Pulmonary Venous Gradients in Healthy Controls and Following the Repair of Total Anomalous Pulmonary Venous Return.

The percent of children who can achieve a normal and physiologic pulmonary venous gradient and flow following the repair of Total Anomalous Pulmonary Venous Return (TAPVR) is not known. Pulmonary venous confluence gradients from infants with supra-, infra-, or mixed TAPVR, repaired using a direct anastomotic connection were measured. Data from age, weight, and gender-matched controls established the normal pulmonary venous gradient range (0.30-0.94 mmHg). TAPVR subjects were divided into three groups: (I) pulmonary venous gradient < 2 × normal with multiphasic flow (II) pulmonary venous gradient > 2 × normal with multiphasic flow, and (III) pulmonary venous gradient > 2 × normal with monophasic flow. From 63 children following TAPVR repair and 63 matched controls, pulmonary venous gradients were significantly lower [0.5 mmHg (IQR:0.4, 0.6) vs 1.6 mmHg (IQR:1.0, 2.4); p < 0.001], and multiphasic flow more frequent (100 vs. 84.1%; p = 0.001) within the control group. There were 38 children (60.3%) in group I, 15 (23.8%) in group II, and 10 (15.8%) in group III. Children in Group I were significantly older at the time of repair, had shorter cardiopulmonary bypass times, and did not utilize deep hypothermic circulatory arrest (DHCA). Multivariate analysis confirmed that avoiding DHCA [Odds Ratio 0.931 (0.913,0.994; p = 0.002)] and shorter cardiopulmonary bypass times [Odds Ratio 0.962 (0.861,0.968; p = 0.02)] during repair were associated with the lowest pulmonary venous gradients and multiphasic flow. Following TAPVR repair with a direct anastomosis, the majority of children can achieve a gradient two times normal or less with multiphasic pulmonary venous flow.

A modified approach in the repair of type I and II truncus arteriosus to promote branch pulmonary arterial growth and limit early reoperation.

Objective: Maintaining adequate branch pulmonary arterial growth is critical in preventing early (<3 years) right ventricular outflow tract reoperation after the repair of truncus arteriosus. We hypothesized that a modified truncus arteriosus repair keeping the branch pulmonary arteries in situ would promote branch pulmonary arterial growth and limit early right ventricular outflow tract reoperation. Methods: For infants requiring repair for type I and II truncus arteriosus, the truncal root was septated through a hockey stick incision keeping the branch pulmonary arteries in situ, the ventricular septal defect was closed, and a short aortic homograft was used to reconstruct the right ventricular outflow tract. Echocardiograms measured preoperative and follow-up branch pulmonary artery diameter. Results: Between 1998 and 2020, 41 infants were repaired using the modified approach (type I, 28; type II, 13). With a median follow-up of 11.6 (interquartile range, 3.1-15.5) years, there was no significant change between preoperative left pulmonary artery and right pulmonary artery Z-scores and their corresponding follow-up measurement (left pulmonary artery: 0.97, interquartile range, 0.6-1.6 vs left pulmonary artery: 1.4, interquartile range, -0.3 to 1.9) (right pulmonary artery: 0.6, interquartile range, -0.4 to 1.7 vs right pulmonary artery: 0.3 interquartile range, 0.5-0.9). Only 7.3% (n = 2) of follow-up right pulmonary artery Z-scores were less than 2.5 Z-scores below preoperative measurements. Four children (9.8%) required early right ventricular outflow tract reoperation. On multivariable analysis, larger conduit Z-scores were associated with greater time to right ventricular outflow tract reoperation (hazard ratio, 0.55, confidence interval, 0.307-0.984; P = .043). Conclusions: Maintaining the branch pulmonary arteries in situ at initial truncus arteriosus repair allows for branch pulmonary arterial growth, limiting early right ventricular outflow tract reoperation.

Methylprednisolone for Heart Surgery in Infants - A Randomized, Controlled Trial.

BACKGROUND: Although perioperative prophylactic glucocorticoids have been used for decades, whether they improve outcomes in infants after heart surgery with cardiopulmonary bypass is unknown. METHODS: We conducted a multicenter, prospective, randomized, placebo-controlled, registry-based trial involving infants (<1 year of age) undergoing heart surgery with cardiopulmonary bypass at 24 sites participating in the Society of Thoracic Surgeons Congenital Heart Surgery Database. Registry data were used in the evaluation of outcomes. The infants were randomly assigned to receive prophylactic methylprednisolone (30 mg per kilogram of body weight) or placebo, which was administered into the cardiopulmonary-bypass pump-priming fluid. The primary end point was a ranked composite of death, heart transplantation, or any of 13 major complications. Patients without any of these events were assigned a ranked outcome based on postoperative length of stay. In the primary analysis, the ranked outcomes were compared between the trial groups with the use of odds ratios adjusted for prespecified risk factors. Secondary analyses included an unadjusted odds ratio, a win ratio, and safety outcomes. RESULTS: A total of 1263 infants underwent randomization, of whom 1200 received either methylprednisolone (599 infants) or placebo (601 infants). The likelihood of a worse outcome did not differ significantly between the methylprednisolone group and the placebo group (adjusted odds ratio, 0.86; 95% confidence interval [CI], 0.71 to 1.05; P = 0.14). Secondary analyses (unadjusted for risk factors) showed an odds ratio for a worse outcome of 0.82 (95% CI, 0.67 to 1.00) and a win ratio of 1.15 (95% CI, 1.00 to 1.32) in the methylprednisolone group as compared with the placebo group, findings suggestive of a benefit with methylprednisolone; however, patients in the methylprednisolone group were more likely than those in the placebo group to receive postoperative insulin for hyperglycemia (19.0% vs. 6.7%, P<0.001). CONCLUSIONS: Among infants undergoing surgery with cardiopulmonary bypass, prophylactic use of methylprednisolone did not significantly reduce the likelihood of a worse outcome in an adjusted analysis and was associated with postoperative development of hyperglycemia warranting insulin in a higher percentage of infants than placebo. (Funded by the National Center for Advancing Translational Sciences and others; STRESS ClinicalTrials.gov number, NCT03229538.).

Risk Stratification for Congenital Heart Surgery for ICD-10 Administrative Data (RACHS-2).

BACKGROUND: As the cardiac community strives to improve outcomes, accurate methods of risk stratification are imperative. Since adoption of International Classification of Disease-10th Revision (ICD-10) in 2015, there is no published method for congenital heart surgery risk stratification for administrative data. OBJECTIVES: This study sought to develop an empirically derived, publicly available Risk Stratification for Congenital Heart Surgery (RACHS-2) tool for ICD-10 administrative data. METHODS: The RACHS-2 stratification system was iteratively and empirically refined in a training dataset of Pediatric Health Information Systems claims to optimize sensitivity and specificity compared with corresponding locally held Society of Thoracic Surgeons-Congenital Heart Surgery (STS-CHS) clinical registry data. The tool was validated in a second administrative data source: New York State Medicaid claims. Logistic regression was used to compare the ability of RACHS-2 in administrative data to predict operative mortality vs STAT Mortality Categories in registry data. RESULTS: The RACHS-2 system captured 99.6% of total congenital heart surgery registry cases, with 1.0% false positives. RACHS-2 predicted operative mortality in both training and validation administrative datasets similarly to STAT Mortality Categories in registry data. C-statistics for models for operative mortality in training and validation administrative datasets-adjusted for RACHS-2-were 0.76 and 0.84 (95% CI: 0.72-0.80 and 0.80-0.89); C-statistics for models for operative mortality-adjusted for STAT Mortality Categories-in corresponding clinical registry data were 0.75 and 0.84 (95% CI: 0.71-0.79 and 0.79-0.89). CONCLUSIONS: RACHS-2 is a risk stratification system for pediatric cardiac surgery for ICD-10 administrative data, validated in 2 administrative-registry-linked datasets. Statistical code is publicly available upon request.

Enoxaparin Reduces Catheter-associated Venous Thrombosis After Infant Cardiac Surgery.

BACKGROUND: Central venous catheter (CVC) related venous thrombosis (VT) after pediatric cardiac surgery increases morbidity and mortality. Although VT prevention using low-dose anticoagulation therapy has proven ineffective, anticoagulation therapy using high-dose enoxaparin to achieve a therapeutic anti-Xa level has not been studied. We hypothesized that high-dose enoxaparin would reduce VT after pediatric cardiac surgery. METHODS: Enoxaparin was administered to infants aged less than 150 days when postoperative CVC duration was anticipated to extend beyond 5 days. The primary outcome was the rate of VT, reexploration for bleeding, and postoperative red blood cell transfusions per 1000 CVC days. RESULTS: From 2012 to 2019, 157 infants were treated with enoxaparin. Infants were divided into two groups: (1) subtherapeutic (n = 51), in which therapeutic anti-Xa level (0.5 to 1.0 IU/mL) was not achieved; and (2) therapeutic (n = 106), in which therapeutic anti-Xa level was achieved. Baseline demographics demonstrated a lower age at operation in the therapeutic group. The subtherapeutic group had a higher VT rate per 1000 CVC days (8.2) compared with the therapeutic group (2.6; P = .005). Reexploration for bleeding was similar between groups. The number of postoperative red blood cell transfusions per 1000 CVC days was significantly greater in the subtherapeutic group (109.4 vs 81.6; P = .008). Multivariate analysis demonstrated that higher median anti-Xa levels reduced the risk of VT (odds ratio 0.02; 95% confidence interval, 0.001 to 0.63; P = .02). CONCLUSIONS: These data suggest that enoxaparin treatment resulting in a therapeutic anti-Xa level reduces postoperative CVC-associated VT without increasing bleeding complications.

Factors Associated With an Abnormal Blood Pressure Response During Exercise After Coarctation Repair.

BACKGROUND: Although resting blood pressures following aortic arch repair or the extended end-to-end anastomosis (EEA) repair for coarctation can be physiologic, factors associated with an abnormal blood pressure response after exercise are unknown. We measured blood pressure gradients following exercise in children who had undergone previous repair in accordance with a surgical selection algorithm and sought to identify factors associated with an abnormal blood pressure response. METHODS: In accordance with our practice's surgical algorithm for repair of coarctation, infants were stratified to aortic arch repair when the distal transverse arch-to-left carotid artery ratio (DTA:LCA) ≤ 1.0, or when a brachiocephalic trunk or intra-cardiac lesion requiring repair was present. A thoracotomy and EEA were otherwise used. A follow-up exercise stress test (EST) measured the arm:leg blood pressure gradient after exercise, and a gradient ≥ 20 mm Hg was defined as an abnormal blood pressure response. RESULTS: Thirty-seven infants who had previously undergone coarctation repair (aortic arch repair-19, EEA-18) completed an EST at 12.3 ± 2.2 years of age. Thirteen (35%) children (aortic arch repair-5, EEA-8; p = .3) exhibited an abnormal blood pressure response. Factors associated with an abnormal blood pressure response included: smaller DTA:LCA ratios prior to repair (1.0 ± .2 vs. 1.2 ± .3; p = .04) and greater body weight at the time of EST (57.5 ± 19.1 vs. 40.9 ± 15.6 kg; p = .03). CONCLUSION: An abnormal blood pressure response following exercise is associated with smaller DTA:LCA ratios at the time of repair and increased weight during follow-up suggesting that patients with these factors warrant close observation.

Mitochondrial ATP Synthase Tetramer Disassembly following Blood-Based or del Nido Cardioplegia during Neonatal Cardiac Surgery.

Conservation of mitochondrial adenosine triphosphate (ATP) synthase proteins during ischemia is critical to preserve ATP supply and ventricular function. Following myocardial ischemia in adults, higher order ATP synthase tetramer proteins disassemble into simpler monomer units, reducing the efficiency of ATP production. However, it is unknown if myocardial ischemia following the use of cardioplegia results in tetramer disassembly in neonates, and whether it can be mitigated by cardioplegia if it does occur. We investigated myocardial ATP synthase tetramer disassembly in both a neonatal lamb cardiac surgery model and in neonatal children requiring cardiac surgery for the repair of congenital heart disease. Neonatal lambs (Ovis aries) were placed on cardiopulmonary bypass (CPB) and underwent cardioplegic arrest using a single dose of 30 mL/kg antegrade blood-based potassium cardioplegia (n = 4) or a single dose of 30 mL/kg antegrade del Nido cardioplegia (n = 6). Right ventricular biopsies were taken at baseline on CPB (n = 10) and after approximately 60 minutes of cardioplegic arrest before the cross clamp was released (n = 10). Human right ventricular biopsies (n = 3) were taken following 40.0 ± 23.1 minutes of ischemia after a single dose of antegrade blood-based cardioplegia. Protein complexes were separated on clear native gels and the tetramer to monomer ratio quantified. From the neonatal lamb model regardless of the cardioplegia strategy, the tetramer:monomer ratio decreased significantly during ischemia from baseline measurements (.6 ± .2 vs. .5 ± .1; p = .03). The del Nido solution better preserved the tetramer:monomer ratio when compared to the blood-based cardioplegia (Blood .4 ± .1 vs. del Nido .5 ± .1; p = .05). The tetramer:monomer ratio following the use of blood-based cardioplegia in humans aligned with the lamb data (tetramer:monomer .5 ± .2). These initial results suggest that despite cardioprotection, ischemia during neonatal cardiac surgery results in tetramer disassembly which may be limited when using the del Nido solution.

In Vitro and In Vivo Comparison of Hemoglobin and Electrolytes Following the Collection of Cell Saver Blood Washed with Either Normal Saline or Plasma-Lyte A.

Cell saver blood is typically washed with normal saline (NS); however, recent studies have reported decreased red blood cell hemolysis and increased platelet function when a more physiologic washing solution, such as Plasma-Lyte A (PL-A) is used. We evaluated the in vitro and in vivo effects of NS compared to PL-A as washing solutions for cell saver blood in pediatric cardiac surgery. Cell saver blood was re-infused for up to 24 hours post-collection. Laboratory and clinical data were collected from infants receiving cell saver washed with either NS (n = 20) or PL-A (n = 21). Compositions of the cell saver blood were compared between groups at 5 in vitro time points and in vivo patient blood at 24 hours post-bypass. Although there were differences in in vitro laboratory values between groups; 24 hours post-bypass, in vivo results were similar. Our data supports 24-hour reinfusion of cell saver washed with either NS versus PL-A in pediatric cardiac surgery patients, and provides data on the differences in cell saver composition to guide future studies.

Improving Longitudinal Outcomes, Efficiency, and Equity in the Care of Patients With Congenital Heart Disease.

BACKGROUND: Longitudinal follow-up, resource utilization, and health disparities are top congenital heart research and care priorities. Medicaid claims include longitudinal data on inpatient, outpatient, emergency, pharmacy, rehabilitation, home health utilization, and social determinants of health-including mother-infant pairs. OBJECTIVES: The New York Congenital Heart Surgeons Collaborative for Longitudinal Outcomes and Utilization of Resources linked robust clinical details from locally held state and national registries from 10 of 11 New York congenital heart centers to Medicaid claims, building a novel, statewide mechanism for longitudinal assessment of outcomes, expenditures, and health inequities. METHODS: The authors included all children <18 years of age undergoing cardiac surgery in The Society of Thoracic Surgeons Congenital Heart Surgery Database or the New York State Pediatric Congenital Cardiac Surgery Registry from 10 of 11 New York centers, 2006 to 2019. Data were linked via iterative, ranked deterministic matching on direct identifiers. Match rates were calculated and compared. Proportions of the linked cohort trackable over 3, 5, and 10 years were described. RESULTS: Of 14,097 registry cases, 59% (n = 8,322) reported Medicaid use. Of these, 7,414 were linked to New York claims, at an 89% match rate. Of matched cases, the authors tracked 79%, 74%, and 65% of children over 3, 5, and 10 years when requiring near-continuous Medicaid enrollment. Allowing more lenient enrollment criteria, the authors tracked 86%, 82%, and 76%, respectively. Mortality over this time was 7.7%, 8.4%, and 10.0%, respectively. Manual validation revealed ∼100% true matches. CONCLUSIONS: This establishes a novel statewide data resource for assessment of longitudinal outcome, health expenditure, and disparities for children with congenital heart disease.

Intraoperative Cortical Asynchrony Predicts Abnormal Postoperative Electroencephalogram.

BACKGROUND: Postoperative electroencephalograms (EEGs) can identify seizure activity and neurologic dysfunction in high-risk neonates requiring cardiac surgical procedures. Although intraoperative EEG monitoring is uncommon, variations in cerebral blood flow and temperature during antegrade cerebral perfusion (ACP) can manifest as cortical asynchrony during EEG monitoring. We hypothesized that intraoperative EEG cortical asynchrony would identify neonates at risk for abnormal postoperative EEG tracings. METHODS: Neonates requiring ACP for cardiac repair or palliation had continuous baseline, intraoperative, and postoperative hemodynamic and EEG monitoring. Synchronous and asynchronous cortical bursts were quantified during (1) cooling before ACP, (2) ACP, and (3) rewarming. Asynchronous bursts were defined as interhemispheric variations in electrical voltage or frequency. Neonates were divided into 2 groups, those with and without an abnormal postoperative EEG, which was defined as either persistent asynchrony for more than 2 hours or seizure activity on EEG. RESULTS: Among 40 neonates, 296 asynchronous bursts were noted, most commonly during rewarming. Eight (20%) neonates had an abnormal postoperative EEG (seizure activity, n = 3; persistent asynchrony, n = 5). Baseline demographics and intraoperative hemodynamics were similar between the groups. However, the total number of intraoperative asynchronous bursts was greater in neonates with an abnormal postoperative EEG (17 [11, IQR:24] vs 3 [IQR:1, 7]; P < .001). Multivariate analysis confirmed that the number of asynchronous bursts was independently associated with an abnormal postoperative EEG (odds ratio,1.35; confidence interval,:1.10, 1.65; P = .004). CONCLUSIONS: Neonates with a greater number of intraoperative asynchronous cortical bursts had an abnormal postoperative EEG.

Neurodevelopmental Delay After the Neonatal Repair of Coarctation and Arch Obstruction.

BACKGROUND: Although single ventricle physiology and cyanosis are known risk factors for neurodevelopmental delay (NDD), the impacts of isolated coarctation (Iso CoA) repair or arch reconstruction (AR) are less understood. METHODS: The Vineland Adaptive Behavior Scales, third edition, prospectively evaluated children without a genetic syndrome. An overall composite score, normalized to age and sex, was generated from individual domain scores. NDD was defined as a composite or domain score at least 1 SD less than the established mean. Iso CoA was repaired using a left thoracotomy, whereas AR was performed using a sternotomy and cardiopulmonary bypass. Children with a structurally normal heart and without previous surgery were used as control patients. RESULTS: Of 60 children, 50 required neonatal repair (12 for Iso CoA, 38 for AR), and 10 were control patients. From the entire cohort of children who required neonatal coarctation repair (Iso CoA + AR) composite (93.9 ± 15.9 vs 105.0 ± 7.4; P = .004) and all domain scores were significantly lower than control patients. NDD was present in 25 of 50 children after repair and in 0 of 10 control patients (P = .003). Similarly, the prevalence of NDD was significantly greater after Iso CoA repair (58.3% vs 0%; P = .005) and AR (47.3% vs 0%; P = .007) than in the control population, but no significant difference was found between the Iso CoA and AR groups (P = .74). CONCLUSIONS: In this small cohort, half of the neonates who required either Iso CoA repair or AR exhibit NDD at an intermediate-term follow-up.

Met-Hemoglobin Is a Biomarker for Poor Oxygen Delivery in Infants Following Surgical Palliation.

BACKGROUND: Infants with cyanotic congenital heart disease demonstrate wide fluctuations in hemoglobin (Hb), oxygen saturation, and cardiac output following palliation. Methemoglobin (Met-Hb), the product of Hb oxidation, may represent a compensatory mechanism during hypoxia and may be utilized as a biomarker. METHODS: Arterial and venous Met-Hb levels were obtained from infants requiring palliation. The primary outcome was to describe the relationship between Met-Hb and other indices of tissue oxygenation (venous saturation, estimated arteriovenous oxygen difference [Est AV-Diff], and lactate). Secondary outcomes were to determine the impact of elevated Met-Hb levels ≥1.0% and the effect of red blood cell (RBC) transfusion on Met-Hb levels. RESULTS: Fifty infants and 465 Met-Hb values were studied. Venous Met-Hb levels were significantly higher than arterial levels (venous: 0.84% ± 0.36% vs arterial: 0.45% ± 0.18%; P < .001). Venous Met-Hb demonstrated a significant inverse relationship with venous oxygen saturation (R = -0.6; P < .001) and Hb (R = -0.3, P < .001) and a direct relationship with the Est AV-Diff (R = 0.3, P < .001). A total of 129 (29.6%) venous Met-Hb values were elevated (≥1.0%) and were associated with significantly lower Hb and venous saturation levels and higher Est AV-Diff and lactate levels. Methemoglobin levels decreased significantly following 65 RBC transfusions (0.94 ± 0.40 vs 0.77 ± 0.34; P < .001). Linear mixed models demonstrated that higher venous Met-Hb levels were associated with lower measures of tissue oxygenation and not related to any preoperative clinical differences. CONCLUSION: Methemoglobin may be a clinically useful marker of tissue oxygenation in infants following surgical palliation.

Serial Follow-Up of Two Surgical Strategies for the Repair of Tetralogy of Fallot.

Adverse events following tetralogy of Fallot repair include arrhythmia, reoperation, and death. While limiting the right ventriculotomy mitigates these events over the short and intermediate term, the impact over the long term is unknown. Children requiring tetralogy of Fallot repair were divided into 2 groups: extended right ventriculotomy vs limited right ventriculotomy with transatrial ventricular septal defect closure. Follow-up office ECGs and Holter monitoring, exercise stress tests, and echocardiograms were obtained in the first, second, and third postoperative decades. The primary outcome was cumulative events defined as reoperation, arrhythmia, or death. The extended and limited right ventriculotomy techniques were used in 21 and 17 children, respectively. Cumulative survival was 93.6% at 30 years and was not different between groups. While 10-year (42.9% vs 5.9%, P = 0.02) event rates favored the limited ventriculotomy technique, there were no significant differences at 20 or 25 years. Cox proportional hazard analysis demonstrated that the limited ventriculotomy technique was independently associated with lower events at 10 years (hazard ratio 0.03, 95% confidence interval 0.0016, 0.5697, P = 0.01). The limited ventriculotomy group had greater exercise capacity in the second decade but not the third. Right ventricular end-diastolic diameter Z score was not different at 10 or 20 years, but was significantly smaller in the limited ventriculotomy group at 30 years (5.55 ± 1.69 vs 4.14 ± 0.63, P = 0.03). Limiting the right ventriculotomy during tetralogy of Fallot repair limits 10-year events, improves exercise capacity at 20 years, and attenuates late right ventricular dilation.

Damus-Kaye-Stansel procedure avoids coronary obstruction in complex D-transposition.

Although all coronary anatomy in D-transposition of the great arteries may be "switchable," there are reports in the literature of early and late coronary obstruction following the arterial switch operation. The Damus-Kaye-Stansel procedure does not risk injury to the coronary arteries, and unlike the atrial switch, commits the left ventricle to the systemic circulation. We present a series of four neonates over 22 years with D-transposition of the great arteries and a concomitant coronary artery anomaly precluding arterial switch that were repaired using a Damus-Kaye-Stansel procedure and right ventricle to pulmonary artery conduit.