Prolonged Inotrope Use After Surgery for Congenital Heart Disease: A Common Occurrence with a High Burden of Mortality.

Outcomes in patients requiring prolonged inotropes (PI) following surgery for congenital heart disease (CHD) have not been well studied. We aimed to describe the burden of PI use in the immediate postoperative period after CHD surgery and identify risk factors for in-hospital mortality. We conducted a retrospective cohort study using the Pediatric Health Information System® (PHIS) database. Patients 0-18 years with CHD who underwent cardiovascular surgery from 2010 to 2020 were included. Patients who received inotropic medications for > 7 consecutive days after surgery were in the PI group and all others in the control group. Patients who died before 7 days were excluded. Multivariable mixed-effect logistic regression was used to examine risk factors for in-hospital mortality. There were 110,271 patients from 48 centers included, 10,292 in the PI group and 99,979 in the control group. In-hospital mortality was significantly higher in the PI group (24.9% vs. 4.6%, p < 0.001). Ventricular assist device use was rare (1.6%). After adjustment, odds of in-hospital mortality in the PI group was 3.5 (95% CI 3.3-3.8) times higher than in controls. Independent risk factors for in-hospital mortality were age, non-White race, class of CHD, number of complex chronic conditions, preoperative inotrope, preoperative extracorporeal membrane oxygenation, sepsis, stroke, renal failure, number of inotropes at 7 days, and discharge year (p < 0.01 for all). Postoperative PI use in CHD is common and carries a considerable burden of mortality. Additional work is needed to understand which risk factors are modifiable and which patients may benefit from reintervention or advanced heart failure therapies.

Long-term outcomes following the Ross procedure in neonates and infants: A multi-institutional analysis.

OBJECTIVES: For neonates and infants with aortic valve pathology, the Ross procedure historically has been associated with high rates of morbidity and mortality. Data regarding long-term durability are lacking. METHODS: The international, multi-institutional Ross Collaborative included 6 tertiary care centers. Infants who underwent a Ross operation between 1996 and 2016 (allowing a minimum 5 years of follow-up) were retrospectively identified. Serial echocardiograms were examined to study evolution in neoaortic size and function. RESULTS: Primary diagnoses for the 133 patients (n = 30 neonates) included isolated aortic stenosis (14%, n = 19), Shone complex (14%, n = 19), and aortic stenosis plus other (excluding Shone complex; n = 95, 71%), including arch obstruction (n = 55), left ventricular hypoplasia (n = 9), and mitral disease (moderate or greater stenosis or regurgitation, n = 31). At the time of the Ross procedure, median age was 96 days (interquartile range, 36-186), and median weight was 4.4 kg (3.6-6.5). In-hospital mortality occurred in 13 of 133 patients (10%) (4/30 [13%] neonates). Postdischarge mortality occurred in 10 of 120 patients (8%) at a median of 298 days post-Ross. Post-Ross neoaortic dilatation occurred, peaking at 4 to 5 SDs above normal at 2 to 3 years before returning to near-baseline z-score at a median follow-up of 11.5 [6.4-17.4] years. Autograft/left ventricular outflow tract reintervention was required in 5 of 120 patients (4%) at a median of 10.3 [4.1-12.8] years. Freedom from moderate or greater neoaortic regurgitation was 86% at 15 years. CONCLUSIONS: Neonates and infants experience excellent postdischarge survival and long-term freedom from autograft reintervention and aortic regurgitation after the Ross. Neoaortic dilatation normalizes in this population in the long-term. Increased consideration should be given to Ross in neonates and infants with aortic valve disease.

Preliminary report of a thoracic duct-to-pulmonary vein lymphovenous anastomosis in swine: A novel technique and potential treatment for lymphatic failure.

OBJECTIVE: The thoracic duct is the largest lymphatic vessel in the body, and carries fluid and nutrients absorbed in abdominal organs to the central venous circulation. Thoracic duct obstruction can cause significant failure of the lymphatic circulation (i.e., protein-losing enteropathy, plastic bronchitis, etc.). Surgical anastomosis between the thoracic duct and central venous circulation has been used to treat thoracic duct obstruction but cannot provide lymphatic decompression in patients with superior vena cava obstruction or chronically elevated central venous pressures (e.g., right heart failure, single ventricle physiology, etc.). Therefore, this preclinical feasibility study sought to develop a novel and optimal surgical technique for creating a thoracic duct-to-pulmonary vein lymphovenous anastomosis (LVA) in swine that could remain patent and preserve unidirectional lymphatic fluid flow into the systemic venous circulation to provide therapeutic decompression of the lymphatic circulation even at high central venous pressures. METHODS: A thoracic duct-to-pulmonary vein LVA was attempted in 10 piglets (median age 80 [IQR 80-83] days; weight 22.5 [IQR 21.4-26.8] kg). After a right thoracotomy, the thoracic duct was mobilized, transected, and anastomosed to the right inferior pulmonary vein. Animals were systemically anticoagulated on post-operative day 1. Lymphangiography was used to evaluate LVA patency up to post-operative day 7. RESULTS: A thoracic duct-to-pulmonary vein LVA was successfully completed in 8/10 (80.0%) piglets, of which 6/8 (75.0%) survived to the intended study endpoint without any complication (median 6 [IQR 4-7] days). Initially, 2/10 (20.0%) LVAs were aborted intraoperatively, and 2/10 (20.0%) animals were euthanized early due to post-operative complications. However, using an optimized surgical technique, the success rate for creating a thoracic duct-to-pulmonary vein LVA in six animals was 100%, all of which survived to their intended study endpoint without any complications (median 6 [IQR 4-7] days). LVAs remained patent for up to seven days. CONCLUSION: A thoracic duct-to-pulmonary vein LVA can be completed safely and remain patent for at least one week with systemic anticoagulation, which provides an important proof-of-concept that this novel intervention could effectively offload the lymphatic circulation in patients with lymphatic failure and elevated central venous pressures.

Lymphatic failure and lymphatic interventions: Knowledge gaps and future directions for a new frontier in congenital heart disease.

Lymphatic failure is a broad term that describes the lymphatic circulation's inability to adequately transport fluid and solutes out of the interstitium and into the systemic venous circulation, which can result in dysfunction and dysregulation of immune responses, dietary fat absorption, and fluid balance maintenance. Several investigations have recently elucidated the nexus between lymphatic failure and congenital heart disease, and the associated morbidity and mortality is now well-recognized. However, the precise pathophysiology and pathogenesis of lymphatic failure remains poorly understood and relatively understudied, and there are no targeted therapeutics or interventions to reliably prevent its development and progression. Thus, there is growing enthusiasm towards the development and application of novel percutaneous and surgical lymphatic interventions. Moreover, there is consensus that further investigations are needed to delineate the underlying mechanisms of lymphatic failure, which could help identify novel therapeutic targets and develop innovative procedures to improve the overall quality of life and survival of these patients. With these considerations, this review aims to provide an overview of the lymphatic circulation and its vasculature as it relates to current understandings into the pathophysiology and pathogenesis of lymphatic failure in patients with congenital heart disease, while also summarizing strategies for evaluating and managing lymphatic complications, as well as specific areas of interest for future translational and clinical research efforts.

Increased utilization of the hybrid procedure is not associated with improved early survival for newborns with hypoplastic left heart syndrome: a single-centre experience.

OBJECTIVES: The primary objectives were to examine utilization of the Hybrid versus the Norwood procedure for patients with hypoplastic left heart syndrome or variants and the impact on hospital mortality. The Hybrid procedure was 1st used at our institution in 2004. METHODS: Review of all subjects undergoing the Norwood or Hybrid procedure between 1 January 1984 and 31 December 2022. The study period was divided into 8 eras: era 1, 1984-1988; era 2, 1989-1993; era 3, 1994-1998; era 4, 1999-2003; era 5, 2004-2008; era 6, 2009-2014; era 7, 2015-2018 and era 8, 2019-2022. The primary outcome was in-hospital mortality. Mortality rates were computed using standard binomial proportions with 95% confidence intervals. Rates across eras were compared using an ordered logistic regression model with and adjusted using the Tukey-Kramer post-hoc procedure for multiple comparisons. In the risk-modelling phase, logistic regression models were specified and tested. RESULTS: The Norwood procedure was performed in 1899 subjects, and the Hybrid procedure in 82 subjects. Use of the Hybrid procedure increased in each subsequent era, reaching 30% of subjects in era 8. After adjustment for multiple risk factors, use of the Hybrid procedure was significantly and positively associated with hospital mortality. CONCLUSIONS: Despite the increasing use of the Hybrid procedure, overall mortality for the entire cohort has plateaued. After adjustment for risk factors, use of the Hybrid procedure was significantly and positively associated with mortality compared to the Norwood procedure.

Early Impairment of Cerebral Bioenergetics After Cardiopulmonary Bypass in Neonatal Swine.

Objectives: We previously demonstrated cerebral mitochondrial dysfunction in neonatal swine immediately following a period of full-flow cardiopulmonary bypass (CPB). The extent to which this dysfunction persists in the postoperative period and its correlation with other markers of cerebral bioenergetic failure and injury is unknown. We utilized a neonatal swine model to investigate the early evolution of mitochondrial function and cerebral bioenergetic failure after CPB. Methods: Twenty piglets (mean weight 4.4 ± 0.5 kg) underwent 3 h of CPB at 34 °C via cervical cannulation and were followed for 8, 12, 18, or 24 h (n = 5 per group). Markers of brain tissue damage (glycerol) and bioenergetic dysfunction (lactate to pyruvate ratio) were continuously measured in cerebral microdialysate samples. Control animals (n = 3, mean weight 4.1 ± 1.2 kg) did not undergo cannulation or CPB. Brain tissue was extracted immediately after euthanasia to obtain ex-vivo cortical mitochondrial respiration and frequency of cortical microglial nodules (indicative of cerebral microinfarctions) via neuropathology. Results: Both the lactate to pyruvate ratio (P < .0001) and glycerol levels (P = .01) increased in cerebral microdialysate within 8 h after CPB. At 24 h post-CPB, cortical mitochondrial respiration was significantly decreased compared with controls (P = .046). The presence of microglial nodules increased throughout the study period (24 h) (P = .01, R2 = 0.9). Conclusion: CPB results in impaired cerebral bioenergetics that persist for at least 24 h. During this period of bioenergetic impairment, there may be increased susceptibility to secondary injury related to alterations in metabolic delivery or demand, such as hypoglycemia, seizures, and decreased cerebral blood flow.

Diffuse Optical Monitoring of Cerebral Hemodynamics and Oxygen Metabolism during and after Cardiopulmonary Bypass: Hematocrit Correction and Neurological Vulnerability.

Cardiopulmonary bypass (CPB) provides cerebral oxygenation and blood flow (CBF) during neonatal congenital heart surgery, but the impacts of CPB on brain oxygen supply and metabolic demands are generally unknown. To elucidate this physiology, we used diffuse correlation spectroscopy and frequency-domain diffuse optical spectroscopy to continuously measure CBF, oxygen extraction fraction (OEF), and oxygen metabolism (CMRO2) in 27 neonatal swine before, during, and up to 24 h after CPB. Concurrently, we sampled cerebral microdialysis biomarkers of metabolic distress (lactate-pyruvate ratio) and injury (glycerol). We applied a novel theoretical approach to correct for hematocrit variation during optical quantification of CBF in vivo. Without correction, a mean (95% CI) +53% (42, 63) increase in hematocrit resulted in a physiologically improbable +58% (27, 90) increase in CMRO2 relative to baseline at CPB initiation; following correction, CMRO2 did not differ from baseline at this timepoint. After CPB initiation, OEF increased but CBF and CMRO2 decreased with CPB time; these temporal trends persisted for 0-8 h following CPB and coincided with a 48% (7, 90) elevation of glycerol. The temporal trends and glycerol elevation resolved by 8-24 h. The hematocrit correction improved quantification of cerebral physiologic trends that precede and coincide with neurological injury following CPB.

Hereditary haemorrhagic telangiectasia and SMAD4 mutation in a patient with complex single ventricle heart disease.

We report a case of hypoplastic left heart syndrome and with subsequent aortopathy and then found to have hereditary haemorrhagic telangiectasia/juvenile polyposis syndrome due to a germline SMAD4 pathologic variant. The patient's staged palliation was complicated by the development of neoaortic aneurysms, arteriovenous malformations, and gastrointestinal bleeding thought to be secondary to Fontan circulation, but workup revealed a SMAD4 variant consistent with hereditary haemorrhagic telangiectasia/juvenile polyposis syndrome. This case underscores the importance of genetic modifiers in CHD, especially those with Fontan physiology.

The Early History of the Congenital Heart Surgeons' Society.

The concept of a new organization for congenital heart surgeons in North America to discuss their difficult cases and offer each other potential solutions began in 1973. This article pays tribute to the founders of the Congenital Heart Surgeons' Society and offers insight into the desire of these surgeons to improve clinical outcomes for children with congenital heart disease.

The Academic Impact of Congenital Heart Surgeons' Society (CHSS) Studies.

PURPOSE: We reviewed all 64 articles ever published by The Congenital Heart Surgeons' Society (CHSS) Data Center to estimate the academic impact of these peer-reviewed articles. MATERIALS AND METHODS: The Congenital Heart Surgeons' Society has performed research based on 12 Diagnostic Inception Cohorts. The first cohort (Transposition) began enrolling patients on January 1, 1985. We queried PubMed to determine the number of publications that referenced each of the 64 journal articles generated by the datasets of the 12 Diagnostic Inception Cohorts that comprise the CHSS Database. Descriptive summaries of the data were tabulated using mean with standard deviation and median with range. RESULTS: Sixty-four peer-reviewed papers have been published based on the CHSS Database. Fifty-nine peer-reviewed articles have been published based on the 12 Diagnostic Inception Cohorts, and five additional articles have been published based on Data Science. Excluding the recently established Diagnostic Inception Cohort for patients with Ebstein malformation of tricuspid valve, the number of papers published per cohort ranged from 1 for coarctation to 11 for transposition of the great arteries. The 11 articles generated from the CHSS Transposition Cohort were referenced by a total of 111 articles (median number of references per journal article = 9 [range = 0-22, mean = 10.1]). Overall, individual articles were cited by an average of 11 (mean), and a maximum of 41 PubMed-listed publications. Overall, these 64 peer-reviewed articles based on the CHSS Database were cited 692 times in PubMed-listed publications. The first CHSS peer-reviewed article was published in 1987, and during the 35 years from 1987 to 2022, inclusive, the annual number of CHSS publications has ranged from 0 to 7, with a mean of 1.8 publications per year (median = 1, mode = 1). CONCLUSION: Congenital Heart Surgeons' Society studies are widely referenced in the pediatric cardiac surgical literature, with over 10 citations per published article. These cohorts provide unique information unavailable in other sources of data. A tool to access this analysis is available at: [https://data-center.chss.org/multimedia/files/2022/CAI.pdf].

Historical Accounts of Congenital Heart Surgery.

We present historical accounts of congenital heart surgery since the early 1900s, as our specialty evolved from individual heroic efforts into an established and sophisticated surgical specialty with consistent and excellent results. We highlight colleagues and intrepid pioneers who have strived to solve seemingly insurmountable problems during this remarkable journey and celebrate continued success into the 21st century with surgical advances that have resulted in innovative operations, database inquiries, quality measures, new techniques of medical illustration, and the establishment of the Congenital Heart Surgeons' Society, which has become the leading organization dedicated to congenital heart surgery in North America.

The Congenital Heart Surgeons' Society Presidents and Their Contributions.

The Congenital Heart Surgeons' Society (CHSS) was founded by 16 congenital heart surgeons in 1973, who endeavored to share their clinical advances in an informal setting that would stimulate honest and forthright discussions. As the Society grew, prospective studies were organized from a centralized data center that was established and based first in Birmingham, Alabama, thence to Toronto, and recently in a collaboration between Toronto and the Cleveland Clinic. These studies formed the basis for a myriad of outcomes reports that favorably impacted surgical results. The Kirklin-Ashburn Fellowship was created and endowed by the membership which has been successful in training many congenital heart surgeons. The CHSS was then incorporated into a 501(c) (3) not-for-profit organization with bylaws, officers, and committees in 2002. Increased membership followed. The CHSS has become the face of congenital heart surgery in North America by affiliating with the World Journal for Pediatric and Congenital Heart Surgery, having one designated member on the American Board of Thoracic Surgery, and hosting joint meetings with the European Congenital Heart Surgeons Association. Since 2002, 11 presidents have been elected for two-year terms and have guided the advances that have been achieved by the CHSS. Their contributions and achievements are highlighted in chronological order.

Indexed oxygen delivery during pediatric cardiopulmonary bypass is a modifiable risk factor for postoperative acute kidney injury.

BACKGROUND: Acute kidney injury after pediatric cardiac surgery is a common complication with few established modifiable risk factors. We sought to characterize whether indexed oxygen delivery during cardiopulmonary bypass was associated with postoperative acute kidney injury in a large pediatric cohort. METHODS: This was a retrospective analysis of patients under 1 year old undergoing cardiac surgery with cardiopulmonary bypass between January 1, 2013, and January 1, 2020. Receiver operating characteristic curves across values ranging from 260 to 400 mL/min/m2 were used to identify the indexed oxygen delivery most significantly associated with acute kidney injury risk. RESULTS: We included 980 patients with acute kidney injury occurring in 212 (21.2%). After adjusting for covariates associated with acute kidney injury, an indexed oxygen delivery threshold of 340 mL/min/m2 predicted acute kidney injury in STAT 4 and 5 neonates (area under the curve = 0.66, 95% CI = 0.60 - 0.72, sensitivity = 56.1%, specificity = 69.4%). An indexed oxygen delivery threshold of 400 mL/min/m2 predicted acute kidney injury in STAT 1-3 infants (area under the curve = 0.65, 95% CI = 0.58 - 0.72, sensitivity = 52.6%, specificity = 74.6%). CONCLUSION: Indexed oxygen delivery during cardiopulmonary bypass is a modifiable variable independently associated with postoperative acute kidney injury in specific pediatric populations. Strategies aimed at maintaining oxygen delivery greater than 340 mL/min/m2 in complex neonates and greater than 400 mL/min/m2 in infants may reduce the occurrence of postoperative acute kidney injury in the pediatric population.

The use of novel diffuse optical spectroscopies for improved neuromonitoring during neonatal cardiac surgery requiring antegrade cerebral perfusion.

Background: Surgical procedures involving the aortic arch present unique challenges to maintaining cerebral perfusion, and optimal neuroprotective strategies to prevent neurological injury during such high-risk procedures are not completely understood. The use of antegrade cerebral perfusion (ACP) has gained favor as a neuroprotective strategy over deep hypothermic circulatory arrest (DHCA) due to the ability to selectively perfuse the brain. Despite this theoretical advantage over DHCA, there has not been conclusive evidence that ACP is superior to DHCA. One potential reason for this is the incomplete understanding of ideal ACP flow rates to prevent both ischemia from underflowing and hyperemia and cerebral edema from overflowing. Critically, there are no continuous, noninvasive measurements of cerebral blood flow (CBF) and cerebral oxygenation (StO2) to guide ACP flow rates and help develop standard clinical practices. The purpose of this study is to demonstrate the feasibility of using noninvasive, diffuse optical spectroscopy measurements of CBF and cerebral oxygenation during the conduct of ACP in human neonates undergoing the Norwood procedure. Methods: Four neonates prenatally diagnosed with hypoplastic left heart syndrome (HLHS) or a similar variant underwent the Norwood procedure with continuous intraoperative monitoring of CBF and cerebral oxygen saturation (StO2) using two non-invasive optical techniques, namely diffuse correlation spectroscopy (DCS) and frequency-domain diffuse optical spectroscopy (FD-DOS). Changes in CBF and StO2 due to ACP were calculated by comparing these parameters during a stable 5 min period of ACP to the last 5 min of full-body CPB immediately prior to ACP initiation. Flow rates for ACP were left to the discretion of the surgeon and ranged from 30 to 50 ml/kg/min, and all subjects were cooled to 18°C prior to initiation of ACP. Results: During ACP, the continuous optical monitoring demonstrated a median (IQR) percent change in CBF of -43.4% (38.6) and a median (IQR) absolute change in StO2 of -3.6% (12.3) compared to a baseline period during full-body cardiopulmonary bypass (CPB). The four subjects demonstrated varying responses in StO2 due to ACP. ACP flow rates of 30 and 40 ml/kg/min (n = 3) were associated with decreased CBF during ACP compared to full-body CPB. Conversely, one subject with a higher flow6Di rate of 50 ml/kg/min demonstrated increased CBF and StO2 during ACP. Conclusions: This feasibility study demonstrates that novel diffuse optical technologies can be utilized for improved neuromonitoring in neonates undergoing cardiac surgery where ACP is utilized. Future studies are needed to correlate these findings with neurological outcomes to inform best practices during ACP in these high-risk neonates.

Impact of the Southern Thoracic Surgical Association James W. Brooks Scholarship.

BACKGROUND: Medical students and general surgery residents often do not get exposure to cardiothoracic surgery (CTS) because of a decreased emphasis on CTS rotations during their training. The Southern Thoracic Surgical Association (STSA) began offering the Brooks Scholarship to medical students in 2010 and general surgery residents in 2014 to promote CTS. This study examines the impact of the scholarship. METHODS: We examined the history of the award and how STSA administers the award. Next we examined the impact of the award by evaluating the number of medical students and residents who are tracked to complete a CTS program. Finally we performed an analysis of the academic output of the awardees who have completed or were tracked to complete a CTS program. RESULTS: The scholarship was developed to honor the memory of past STSA President Dr James W. Brooks. The award is administered through the STSA scholarship committee and provides medical students and residents funds to attend the STSA annual meeting and the opportunity to spend time with a mentor during the meeting. Eighty-eight percent of medical student recipients (21/24) and 100% of general surgery resident recipients (15/15) have completed or are on track to complete a CTS program. The 36 recipients going into CTS have published a total of 823 papers and 9240 articles have cited those papers. CONCLUSIONS: The STSA medical student and general surgery Brooks scholarship awards were associated with completing or pursuing a career in CTS. STSA should continue the Brooks scholarship to attract talented medical students and residents to CTS.

Incidence of postoperative seizures in neonates following cardiac surgery with regional cerebral perfusion and deep hypothermic circulatory arrest.

Objectives: Historically, our center has primarily used deep hypothermic circulatory arrest, but in recent years some surgeons have selectively used regional cerebral perfusion as an alternative. We aimed to compare the incidence of postoperative electroencephalographic seizure incidence in neonates undergoing surgery with regional cerebral perfusion and deep hypothermic circulatory arrest. Methods: A retrospective analysis was performed in neonates who underwent surgery between 2012 and 2022 with either deep hypothermic circulatory arrest or regional cerebral perfusion with routine postoperative continuous electroencephalography monitoring for 48 hours. Propensity matching was performed to compare postoperative seizure risk between the 2 groups. Results: Among 1136 neonates undergoing cardiac surgery with cardiopulmonary bypass, regional cerebral perfusion was performed in 99 (8.7%) and deep hypothermic circulatory arrest in 604 (53%). The median duration of regional cerebral perfusion was 49 minutes (interquartile range, 38-68) and deep hypothermic circulatory arrest was 41 minutes (interquartile range, 31-49). The regional cerebral perfusion group had significantly longer total support, cardiopulmonary bypass, and aortic crossclamp times. Overall seizure incidence was 11% (N = 76) and 13% (N = 35) in the most recent era (2019-2022). The unadjusted seizure incidence was similar in neonates undergoing regional cerebral perfusion (N = 12, 12%) and deep hypothermic circulatory arrest (N = 64, 11%). After propensity matching, the seizure incidence was similar in neonates undergoing regional cerebral perfusion (N = 12, 12%) and deep hypothermic circulatory arrest (N = 37, 12%) (odds ratio, 0.97; 95% CI, 0.55-1.71; P = .92). Conclusions: In this contemporary single-center experience, the incorporation of regional cerebral perfusion did not result in a change in seizure incidence in comparison with deep hypothermic circulatory arrest. However, unmeasured confounders may have impacted these findings. Further studies are needed to determine the impact, if any, of regional cerebral perfusion on postoperative seizure incidence.

Bioethics Forum of Cardiology in the Young. Quo Vadis?

The Editorial Board of Cardiology in the Young has recently discussed the need for a Bioethics Forum and has given authorisation to proceed with its creation. Herein, we provide the organisational structure and launch process to introduce properly this interesting and timely endeavour. By this communication, we are establishing this Bioethics Forum of Cardiology in the Young . We hope to attract manuscripts concerning timely bioethical subjects and to offer the readership the opportunity to respond to these topics with supporting or opposing views as appropriate. New articles regarding timely topics will be written by the readership, as well as by invited authors, and these articles will be published. We hope to stimulate interactive discussion concerning the published manuscripts, and these manuscripts and the associated discussions will be open to all interested parties.