Frequency, characteristics, antithrombotic therapies, and outcomes of thromboembolism in paediatric patients with CHD undergoing cardiac surgery: a single centre retrospective study.

INTRODUCTION: Thromboembolism is a complication in paediatric patients with CHD requiring cardiac surgery. Previous research has focused on post-operative thromboembolism. This study aimed to describe thromboembolism frequency before or after cardiac surgery in children with CHD. METHODS: We performed a single-centre retrospective study from October 2020 to June 2023 (inclusive). Patients were eligible for inclusion if they were <21 years of age and underwent cardiac surgery. Outcomes of interest included the occurrence and characteristics of thromboembolism in the 12 months before and after surgery, antithrombotic therapies, recurrent thromboembolism, and clinically significant bleeding. RESULTS: Among 260 patients included, 35 (13.5%) developed an index thromboembolism. Twelve (34.3%) patients had an index thromboembolism <12 months before surgery and 23 (65.7%) had an index thromboembolism <12 months after surgery, including 8 (22.9%) patients who had thromboembolism during both exposure periods. The median interquartile range (IQR) time of thromboembolism relative to cardiac surgery was -26 (-4 to -140) days and 15 (4 to 41) days, respectively. Seven (20%) patients had arterial, 18 (51.4%) venous, and 3 (8.6%) had both arterial and venous thromboembolism. Median (IQR) antithrombotic therapy duration was 49 (24-84) days. Nine (25.7%) patients developed recurrent thromboembolism and five (14.3%) patients experienced clinically significant bleeding. CONCLUSIONS: The risk of thromboembolism and recurrence is high both before and after cardiac surgery among paediatric patients with CHD. Prospective multi-centre studies should seek to identify risk factors for preoperative and postoperative thromboembolism to inform the design of future risk-stratified thromboembolism prevention trials in children with CHD.

Ketorolac Dosing and Outcomes in Neonates Following Congenital Heart Surgery: A Retrospective Analysis.

BACKGROUND: Pain management is essential for postoperative surgery. Given the association of opioids with adverse outcomes, interest in the use of nonopioid analgesics, such as ketorolac, has increased. Published data on use in neonates are limited. OBJECTIVES: To describe ketorolac dosing and safety and efficacy outcomes in the first 48 hours postcardiac surgery in neonates. DESIGN: We performed a single-center retrospective cohort study of neonates (ages < 28 d) who received ketorolac following cardiac surgery from November 2020 to July 2023 (inclusive). The primary safety outcome was a clinically significant decline in renal function, as defined by the composite of an increase in serum creatinine by greater than or equal to 0.3 mg/dL from baseline within 96 hours of ketorolac initiation and urine output less than or equal to 0.5 mL/kg/hr for 6 hours. The secondary safety outcome was clinically significant bleeding, defined as the composite of major bleeding by the International Society on Thrombosis and Hemostasis pediatric criteria and severe/fatal bleeding by the criteria of Nellis et al (2019). Efficacy was measured by opioid utilization based on a standardized pain score-driven analgesia protocol. INTERVENTIONS: Ketorolac was administered at 0.5 mg/kg every 6 hours as per an institutional clinical management algorithm. MEASUREMENTS AND MAIN RESULTS: Thirty-nine patients met the eligibility criteria. The median ketorolac dose was 0.5 mg/kg/dose, and median (interquartile range [IQR]) duration of therapy was 48 hours (6-48 hr). No patients experienced a significant decline in renal function, and there were no clinically significant bleeding events. The median (IQR) IV morphine milligram equivalents (MMEs)/kg/d of opioid administration was 0.2 MME/kg/d (0.1-0.25 MME/kg/d) at the time of ketorolac initiation and 0.1 MME/kg/d (0.1-0.2 MME/kg/d) at 48 hours post-ketorolac initiation. CONCLUSIONS: If validated prospectively, these findings suggest that a ketorolac regimen of 0.5 mg/kg/dose every 6 hours in neonates postcardiac surgery may be safe with regard to renal function and bleeding risk. Additional randomized studies would be needed to determine efficacy with regard to opioid-sparing capacity.

National experience with pediatric surgical aortic valve repair: A Pediatric Health Information System analysis.

OBJECTIVE: To characterize national experience with surgical aortic valve repair in pediatric patients. METHODS: Patients in the Pediatric Health Information System database aged 17 years or younger with International Statistical Classification of Diseases and Related Health Problems codes for open aortic valve repair from 2003 to 2022 were included (n = 5582). Outcomes of reintervention during index admission (repeat repair, n = 54; replacement, n = 48; and endovascular intervention, n = 1), readmission (n = 2176), and in-hospital mortality (n = 178) were compared. A logistic regression was performed for in-hospital mortality. RESULTS: One-quarter (26%) of patients were infants. The majority (61%) were boys. Heart failure was present in 16% of patients, congenital heart disease in 73%, and rheumatic disease in 4%. Valve disease was insufficiency in 22% of patients, stenosis in 29%, and mixed in 15%. The highest quartile of centers by volume (median, 101 cases; interquartile range, 55-155 cases) performed half (n = 2768) of cases. Infants had the highest prevalence of reintervention (3%; P < .001), readmission (53%; P < .001), and in-hospital mortality (10%; P < .001). Previously hospitalized patients (median, 6 days; interquartile range, 4-13 days) were at higher risk for reintervention (4%; P < .001), readmission (55%; P < .001), and in-hospital mortality (11%; P < .001), as were patients with heart failure (reintervention [6%; P < .001], readmission [42%; P = .050], and in-hospital mortality [10%; P < .001]). Stenosis was associated with reduced reintervention (1%; P < .001) and readmission (35%; P = .002). The median number of readmissions was 1 (range, 0-6) and time to readmission was 28 days (interquartile range, 7-125 days). A regression of in-hospital mortality identified heart failure (odds ratio, 3.05; 95% CI, 1.59-5.49), inpatient status (odds ratio, 2.40; 95% CI, 1.19-4.82), and infancy (odds ratio, 5.70; 95% CI, 2.60-12.46) as significant. CONCLUSIONS: The Pediatric Health Information System cohort demonstrated success with aortic valve repair; however, early mortality remains high in infants, hospitalized patients, and patients with heart failure.

Dosing, Monitoring, Blood Product Utilization, and Thromboembolic Complications of Four-Factor Prothrombin Complex Concentrate as Part of an Institutional Protocol in Pediatric Cardiac Surgery: A Retrospective Cohort Study.

Pediatric cardiac surgery patients are predisposed to blood loss. Blood product administration can lead to complications. Prothrombin complex concentrates (PCCs) offer potential advantages of factor composition, small volume, decreased immunogenicity/infectious risks, and accessibility. The objective of this study was to describe dosing, monitoring, blood product utilization, and thromboembolic complications of administering four-factor PCC (4F-PCC) in pediatric cardiac surgery. We performed a retrospective review of patients aged <18 years undergoing cardiac surgery from June 2020 to May 2022 (inclusive) who received 4F-PCC. Outcomes of interest included 4F-PCC dosing (units/kg) and number of doses administered, chest tube output, blood product administration, donor exposure, length of stay, and thromboembolic events. Eighty-six patients met eligibility criteria. The median (range) age and weight were 0.37 (0.01-16.3) years and 5.3 (1.6-98) kg, respectively. Median (range) total 4F-PCC dose per patient was 25 (9.2-50) units/kg, with 6 patients (7%) receiving a total of two doses. Median (range) 24-hour postoperative packed red blood cells, platelet, plasma, and cryoprecipitate administration volumes were 0 (0-2.57) mL/kg/24 h, 0 (0-1.09), 0 (0-2.64), and 0 (0-0.28 mL/kg/24 h), respectively. Median (range) length of stay and 24-hour postoperative chest tube output were 10 (6-26) days and 1.1 (0.1-4.2) mL/kg/h, respectively. Two (2%) patients experienced a thromboembolic event within 30 days of 4F-PCC administration. These retrospective findings suggest no worsening of hemostatic parameters, a mild median improvement in fibrinogen, low blood product utilization, and low thromboembolism rates following 4F-PCC use in pediatric cardiac surgery.

Ketorolac in neonates and infants following congenital heart surgery: a retrospective review.

INTRODUCTION: Pain management is essential in the immediate post-surgical period. We sought to describe the ketorolac dose regimen in neonates and infants following cardiac surgery. Secondary outcomes included renal dysfunction, bleeding, and pain management. METHODS: We performed a single-centre retrospective cohort study of neonates and infants (aged < 12 months) who received ketorolac following cardiac surgery, from November 2020 through November 2021 (inclusive). Ketorolac was administered at 0.5 mg/kg every 6 hours. Safety was defined by absence of a clinically significant decline in renal function (i.e., increase in serum creatinine [SCr] by ≥ 0.3 mg/dL from baseline within 48 hours and/or urine output ≤ 0.5 mL/kg/hour for 6 hours) and absence of clinically significant bleeding defined as major by International Society on Thrombosis and Hemostasis paediatric criteria or Severe/Fatal Bleeding Events by Nellis et al. Efficacy measures included pain scores and opioid utilisation. RESULTS: Fifty-five patients met eligibility criteria. The median (range) dose and duration of ketorolac administration was 0.5 mg/kg/dose for 48 (6-90) hours. Among all patients, there was not a statistically significant difference observed in median SCr within 48 hours of baseline (p > .9). There were no major or severe bleeding events. The median (range) opioid requirements (morphine intravenous equivalents per kg per day) at 48 hours post-ketorolac initiation was 0.1 (0-0.8) mg/kg/day. CONCLUSIONS: If validated prospectively, these findings suggest that a ketorolac regimen 0.5 mg/kg/dose every 6 hours in neonates and infants post-cardiac surgery may be safe with regard to renal function and bleeding risk, and effective regarding opioid-sparing capacity.

Survival analysis for pediatric heart transplant patients using a novel machine learning algorithm: A UNOS analysis.

BACKGROUND: Impact of pretransplantation risk factors on mortality in the first year after heart transplantation remains largely unknown. Using machine learning algorithms, we selected clinically relevant identifiers that could predict 1-year mortality after pediatric heart transplantation. METHODS: Data were obtained from the United Network for Organ Sharing Database for years 2010-2020 for patients 0-17 years receiving their first heart transplant (N = 4150). Features were selected using subject experts and literature review. Scikit-Learn, Scikit-Survival, and Tensorflow were used. A train:test split of 70:30 was used. N-repeated k-fold validation was performed (N = 5, k = 5). Seven models were tested, Hyperparameter tuning performed using Bayesian optimization and the concordance index (C-index) was used for model assessment. RESULTS: A C-index above 0.6 for test data was considered acceptable for survival analysis models. C-indices obtained were 0.60 (Cox proportional hazards), 0.61 (Cox with elastic net), 0.64 (gradient boosting), 0.64 (support vector machine), 0.68 (random forest), 0.66 (component gradient boosting), and 0.54 (survival trees). Machine learning models show an improvement over the traditional Cox proportional hazards model, with random forest performing the best on the test set. Analysis of the feature importance for the gradient boosted model found that the top 5 features were the most recent serum total bilirubin, the travel distance from the transplant center, the patient body mass index, the deceased donor terminal Serum glutamic pyruvic transaminase/Alanine transaminase (SGPT/ALT), and the donor PCO2. CONCLUSIONS: Combination of machine learning and expert-based methodology of selecting predictors of survival for pediatric heart transplantation provides a reasonable prediction of 1- and 3-year survival outcomes. SHapley Additive exPlanations can be an effective tool for modeling and visualizing nonlinear interactions.

Expert Consensus Statement: Anatomy, Imaging, and Nomenclature of Congenital Aortic Root Malformations.

Over the past 2 decades, several categorizations have been proposed for the abnormalities of the aortic root. These schemes have mostly been devoid of input from specialists of congenital cardiac disease. The aim of this review is to provide a classification, from the perspective of these specialists, based on an understanding of normal and abnormal morphogenesis and anatomy, with emphasis placed on the features of clinical and surgical relevance. We contend that the description of the congenitally malformed aortic root is simplified when approached in a fashion that recognizes the normal root to be made up of 3 leaflets, supported by their own sinuses, with the sinuses themselves separated by the interleaflet triangles. The malformed root, usually found in the setting of 3 sinuses, can also be found with 2 sinuses, and very rarely with 4 sinuses. This permits description of trisinuate, bisinuate, and quadrisinuate variants, respectively. This feature then provides the basis for classification of the anatomical and functional number of leaflets present. By offering standardized terms and definitions, we submit that our classification will be suitable for those working in all cardiac specialties, whether pediatric or adult. It is of equal value in the settings of acquired or congenital cardiac disease. Our recommendations will serve to amend and/or add to the existing International Paediatric and Congenital Cardiac Code, along with the Eleventh iteration of the International Classification of Diseases provided by the World Health Organization.

Expert Consensus Statement: Anatomy, Imaging, and Nomenclature of Congenital Aortic Root Malformations.

Over the past 2 decades, several categorizations have been proposed for the abnormalities of the aortic root. These schemes have mostly been devoid of input from specialists of congenital cardiac disease. The aim of this review is to provide a classification, from the perspective of these specialists, based on an understanding of normal and abnormal morphogenesis and anatomy, with emphasis placed on the features of clinical and surgical relevance. We contend that the description of the congenitally malformed aortic root is simplified when approached in a fashion that recognizes the normal root to be made up of 3 leaflets, supported by their own sinuses, with the sinuses themselves separated by the interleaflet triangles. The malformed root, usually found in the setting of 3 sinuses, can also be found with 2 sinuses, and very rarely with 4 sinuses. This permits description of trisinuate, bisinuate, and quadrisinuate variants, respectively. This feature then provides the basis for classification of the anatomical and functional number of leaflets present. By offering standardized terms and definitions, we submit that our classification will be suitable for those working in all cardiac specialties, whether pediatric or adult. It is of equal value in the settings of acquired or congenital cardiac disease. Our recommendations will serve to amend and/or add to the existing International Paediatric and Congenital Cardiac Code, along with the Eleventh iteration of the International Classification of Diseases provided by the World Health Organization.

Regionalization or Access to Care? A Joint Pediatric Heart Care Program That Achieves Both: One Program-Two Sites.

Background: Regionalization of care for children with congenital heart disease has been proposed as a method to improve outcomes. This has raised concerns about limiting access to care. We present the details of a joint pediatric heart care program (JPHCP) which utilized regionalization and actually improved access to care. Methods: In 2017, Kentucky Children's Hospital (KCH) launched the JPHCP with Cincinnati Children's Hospital Medical Center (CCHMC). This unique satellite model was the product of several years of planning, leading to a comprehensive strategy with shared personnel, conferences, and a robust transfer system; "one program-two sites." Results: Between March 2017 and the end of June 2022, 355 operations were performed at KCH under the auspices of the JPHCP. As of the most recent published Society of Thoracic Surgeons (STS) outcome report (through the end of June 2021), for all STAT categories, the JPHCP at KCH outperformed the STS overall in postoperative length of stay, and the mortality rate was lower than expected for the case mix. Of the 355 operations, there were 131 STAT 1, 148 STAT 2, 40 STAT 3, and 36 STAT 4 operations, with two operative mortalities: an adult undergoing surgery for Ebstein anomaly, and a premature infant who died from severe lung disease many months after aortopexy. Conclusions: With a select case mix, and by affiliating with a large volume congenital heart center, the creation of the JPHCP at KCH was able to achieve excellent congenital heart surgery results. Importantly, access to care was improved for those children at the more remote location utilizing this one program-two sites model.

The American Association for Thoracic Surgery (AATS) 2022 Expert Consensus Document: Management of infants and neonates with tetralogy of Fallot.

OBJECTIVE: Despite decades of experience, aspects of the management of tetralogy of Fallot with pulmonary stenosis (TOF) remain controversial. Practitioners must consider newer, evolving treatment strategies with limited data to guide decision making. Therefore, the TOF Clinical Practice Standards Committee was commissioned by the American Association for Thoracic Surgery to provide a framework on this topic, focused on timing and types of interventions, management of high-risk patients, technical considerations during interventions, and best practices for assessment of outcomes of the interventions. In addition, the group was tasked with identifying pertinent research questions for future investigations. It is recognized that variability in institutional experience could influence the application of this framework to clinical practice. METHODS: The TOF Clinical Practice Standards Committee is a multinational, multidisciplinary group of cardiologists and surgeons with expertise in TOF. With the assistance of a medical librarian, a citation search in PubMed, Embase, Scopus, and Web of Science was performed using key words related to TOF and its management; the search was restricted to the English language and the year 2000 or later. Articles pertaining to pulmonary atresia, absent pulmonary valve, atrioventricular septal defects, and adult patients with TOF were excluded, as well as nonprimary sources such as review articles. This yielded nearly 20,000 results, of which 163 were included. Greater consideration was given to more recent studies, larger studies, and those using comparison groups with randomization or propensity score matching. Expert consensus statements with class of recommendation and level of evidence were developed using a modified Delphi method, requiring 80% of the member votes with 75% agreement on each statement. RESULTS: In asymptomatic infants, complete surgical correction between age 3 and 6 months is reasonable to reduce the length of stay, rate of adverse events, and need for a transannular patch. In the majority of symptomatic neonates, both palliation and primary complete surgical correction are useful treatment options. It is reasonable to consider those with low birth weight or prematurity, small or discontinuous pulmonary arteries, chromosomal anomalies, other congenital anomalies, or other comorbidities such as intracranial hemorrhage, sepsis, or other end-organ compromise as high-risk patients. In these high-risk patients, palliation may be preferred; and, in patients with amenable anatomy, catheter-based procedures may prove favorable over surgical palliation. CONCLUSIONS: Ongoing research will provide further insight into the role of catheter-based interventions. For complete surgical correction, both transatrial and transventricular approaches are effective; however, the smallest possible ventriculotomy should be utilized. When possible, the pulmonary valve should be spared; and if unsalvageable, reconstruction can be considered. At the conclusion of the operation, adequate relief of the right ventricular outflow obstruction should be confirmed, and identification of a significant fixed anatomical obstruction should prompt further intervention. Given our current knowledge and the gaps identified, we propose several key questions to be answered by future research and potentially by a TOF registry: When to palliate or proceed with complete surgical correction, as well as the ideal type of palliation; the optimal surgical approach for complete repair for the best long-term preservation of right ventricular function; and the utility, efficacy, and durability of various pulmonary valve preservation and reconstruction techniques.

George Daicoff: A Pioneering Surgeon and Humanitarian of The Southern Thoracic Surgical Association.

George Daicoff was a true pioneer who excelled in patient care, research, teaching, and advocacy; he performed cardiac surgery on thousands. He trained at Mayo Clinic under the tutelage of John Kirklin in 1966. He served on the faculty at University of Florida from 1967 to 1977 and became Chief of Thoracic and Cardiovascular Surgery at University of Florida. He then served as Chief of Cardiovascular Surgery at All Children's Hospital from 1977 to 1998. In 1972, he was one of 13 founding members of the Congenital Heart Surgeons' Society (CHSS), and in 1973, he was one of 10 surgeons to attend the first meeting of CHSS. Dr Daicoff won the 1970 Southern Thoracic Surgical Association President's Award for best scientific paper, and the 1996 Southern Thoracic Surgical Association Osler Abbot Award. In 2015, the Southern Thoracic Surgical Association Congenital Heart Surgery President's Award was named the George Daicoff Award.

Impact of Coronavirus-2019 On Pediatric and Adult Heart Transplantation Waitlist Activity and Mortality in The United States: A Descriptive Approach.

BACKGROUND: Transplant centers saw a substantial reduction in deceased donor solid organ transplantation since the beginning of the coronavirus 2019 (COVID-19) pandemic in the United States. There is limited data on the impact of COVID-19 on adult and pediatric heart transplant volume and variation in transplant practices. We hypothesized that heart transplant activity decreased during COVID-19 with associated increased waitlist mortality. METHODS: The United Network for Organ Sharing (UNOS) database was used to identify patients at the time of listing for heart transplant from 2017-2020. Patients were categorized as pediatric (<18 years) or adult (≥18 years) and as pre-COVID (2017-2019) or post-COVID (2020). Regional and statewide data were taken from United States Census Bureau. CovidActNow project was used to obtain COVID-19 mortality rates. FINDINGS: Among pediatric patients, average time on the waiting list decreased by 28 days. Even though the average number of pediatric transplants (n=39 per month) did not change significantly during 2020, there was a temporal decline in the first quarter of 2020 followed by a sharp increase. Overall absolute pediatric waitlist mortality decreased from 5•31 to 4•73, however female mortality increased by 2%. Regional differences in pediatric mortality were observed: Northeast, decreased by 7•5%; Midwest, decreased by 9%; West, increased by 3•5%; and South, increased by 13%. North Dakota (0•55), Oklahoma (0•21) and Hawaii (0•33) showed higher mortality than other states per 100,000. In adults, average time on waiting list increased by 40 days and there was an increase in the number of transplants from 242 to 266. Adult waitlist mortality had a larger decrease, 18•44 to 15•70, with an increase in female mortality of 7%. Regional differences in adult mortality were also observed: Northeast, decreased by 3%; Midwest, increased by 5•5%; West, increased by 4•5% and South, decreased by 5%. Iowa (0•37), Wyoming (0•22), Arkansas (0•18) and Vermont (0•19) had the highest mortality per 100,000 compared to the other states. INTERPRETATION: Pediatric heart transplant volume declined in early 2020 followed by a later increase, while adult transplant volume increased all year round. Although, overall pediatric waitlist mortality decreased, female waitlist mortality increased for both adults and pediatrics. Regional differences in waitlist mortality were observed for both pediatrics and adults. Future studies are needed to understand this initial correlation and to determine the impact of COVID-19 on heart transplant recipients. FUNDING: This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.

Understanding the Aortic Root Using Computed Tomographic Assessment: A Potential Pathway to Improved Customized Surgical Repair.

There is continued interest in surgical repair of both the congenitally malformed aortic valve, and the valve with acquired dysfunction. Aortic valvar repair based on a geometric approach has demonstrated improved durability and outcomes. Such an approach requires a thorough comprehension of the complex 3-dimensional anatomy of both the normal and congenitally malformed aortic root. In this review, we provide an understanding of this anatomy based on the features that can accurately be revealed by contrast-enhanced computed tomographic imaging. We highlight the complimentary role that such imaging, with multiplanar reformatting and 3-dimensional reconstructions, can play in selection of patients, and subsequent presurgical planning for valvar repair. The technique compliments other established techniques for perioperative imaging, with echocardiography maintaining its central role in assessment, and enhances direct surgical evaluation. This additive morphological and functional information holds the potential for improving selection of patients, surgical planning, subsequent surgical repair, and hopefully the subsequent outcomes.

Normative Aortic Valvar Measurements in Adults Using Cardiac Computed Tomography　- A Potential Guide to Further Sophisticate Aortic Valve-Sparing Surgery.

BACKGROUND: A thorough understanding of the anatomy of the aortic valve is necessary for aortic valve-sparing surgery. Normal valvar dimensions and their relationships in the living heart, however, have yet to be fully investigated in a 3-dimensional fashion.Methods and Results:In total, 123 consecutive patients (66±12 years, Men 63%) who underwent coronary computed tomographic angiography were enrolled. Mid-diastolic morphology of the aortic roots, including height of the interleaflet triangles, geometric height, free margin length of each leaflet, effective height, and coaptation length were measured using multiplanar reconstruction images. Average height of the interleaflet triangle, geometric height, free margin length, effective height, and the coaptation length were 17.3±1.8, 14.7±1.3, 32.6±3.6, 8.6±1.4, and 3.2±0.8 mm, respectively. The right coronary aortic leaflet displayed the longest free margin length and shortest geometric height. Geometric height, free margin length, and effective height showed positive correlations with aortic root dimensions. Coaptation length, however, remained constant regardless of aortic root dimensions. CONCLUSIONS: Diversities, as well as characteristic relationships among each value involving the aortic root, were identified using living-heart datasets. The aortic leaflets demonstrated compensatory elongation along with aortic root dilatation to maintain constant coaptation length. These measurements will serve as the standard value for revealing the underlying mechanism of aortic regurgitation to plan optimal aortic valve-sparing surgery.

Heart Transplantation for Pediatric and Congenital Cardiac Disease: A Comparison of Two Eras over 23 Years and 188 Transplants at a Single Institution.

BACKGROUND: To assess changes in patterns of practice and outcomes over time, we reviewed all patients who underwent heart transplantation (HTx) at our institution and compared two consecutive eras with significantly different immunosuppressive protocols (cohort 1 [80 HTx, June 1995-June 2006]; cohort 2 [108 HTx, July 2006-September 2018]). METHODS: Retrospective study of 180 patients undergoing 188 HTx (June 1995-September 2018; 176 first time HTx, 10 second HTx, and 2 third HTx). In 2006, we commenced pre-HTx desensitization for highly sensitized patients and started using tacrolimus as our primary postoperative immunosuppressive agent. The primary outcome was mortality. Survival was modeled by the Kaplan-Meier method. Univariable and multivariable Cox proportional hazard models were created to identify prognostic factors for survival. RESULTS: Our 188 HTx included 18 neonates, 85 infants, 83 children, and 2 adults (>18 years). Median age was 260.0 days (range: 5 days-23.8 years). Median weight was 7.5 kg (range: 2.2-113 kg). Patients in cohort 1 were less likely to have been immunosensitized preoperatively (12.5% vs 28.7%, P = .017). Nevertheless, Kaplan-Meier analysis suggested superior survival in cohort 2 (P = .0045). Patients in cohort 2 were more likely to be alive one year, five years, and ten years after HTx. Multivariable analysis identified the earlier era (hazard ratio [HR] [95% confidence interval] for recent era = 0.32 [0.14-0.73]), transplantation after prior Norwood operation (HR = 4.44 [1.46-13.46]), and number of prior cardiac operations (HR = 1.33 [1.03-1.71]) as risk factors for mortality. CONCLUSIONS: Our analysis of 23 years of pediatric and congenital HTx reveals superior survival in the most recent 12-year era, despite the higher proportion of patients with elevated panel reactive antibody in the most recent era. This improvement was temporally associated with changes in our immunosuppressive strategy.