To define the incidence of definitive necrotising enterocolitis in term infants with CHD and identify risk factors for morbidity/mortality.

We performed a 20-year (2000–2020) single-institution retrospective cohort study of term infants with CHD admitted to the Boston Children’s Hospital cardiac ICU with necrotising enterocolitis (Bell’s stage ≥ II). The primary outcome was a composite of in-hospital mortality and post-necrotising enterocolitis morbidity (need for extracorporeal membrane oxygenation, multisystem organ failure based on the paediatric sequential organ failure assessment score, and/or need for acute gastrointestinal intervention). Predictors included patient characteristics, cardiac diagnosis/interventions, feeding regimen, and severity measures.

Of 3933 term infants with CHD, 2.1% (n = 82) developed necrotising enterocolitis, with 67% diagnosed post-cardiac intervention. Thirty (37%) met criteria for the primary outcome. In-hospital mortality occurred in 14 infants (17%), of which nine (11%) deaths were attributable to necrotising enterocolitis. Independent predictors of the primary outcome included moderate to severe systolic ventricular dysfunction (odds ratio 13.4,confidence intervals 1.13–159) and central line infections pre-necrotising enterocolitis diagnosis (odds ratio 17.7, confidence intervals 3.21–97.0) and mechanical ventilation post-necrotising enterocolitis diagnosis (odds ratio 13.5, confidence intervals 3.34–54.4). Single ventricle, ductal dependency, and feeding related factors were not independently associated with the primary outcome.

The incidence of necrotising enterocolitis was 2.1% in term infants with CHD. Adverse outcomes occurred in greater than 30% of patients. Presence of systolic dysfunction and central line infections prior to diagnosis and need for mechanical ventilation after diagnosis of necrotising enterocolitis can inform risk triage and prognostic counseling for families.

In single-ventricle patients undergoing staged-bidirectional Glenn, 36–59% have aorto-pulmonary collateral flow, but risk factors and clinical outcomes are unknown. We hypothesise that shunt type and catheter haemodynamics may predict pre-bidirectional Glenn aorto-pulmonary collateral burden, which may predict death/transplantation, pulmonary artery or aorto-pulmonary collateral intervention.

Retrospective cohort study of patients undergoing a Norwood procedure for single-ventricle anatomy. Covariates included clinical and haemodynamic characteristics up to/including pre-bidirectional Glenn catheterisation and aorto-pulmonary collateral burden at pre-bidirectional Glenn catheterisation. Multivariable models used to evaluate relationships between risk factors and outcomes.

From January 2011 to March 2016, 104 patients underwent Norwood intervention. Male sex (odds ratio 3.36, 95% confidence interval 1.17–11.4), age at pre-bidirectional Glenn assessment (2.12, 1.33–3.39 per month), and pulmonary to systemic flow ratio (1.23, 1.08–1.41 per 0.1 unit) were associated with aorto-pulmonary collateral burden. Aorto-pulmonary collateral burden was not associated with death/transplantation (hazard ratio 1.19, 95% confidence interval 0.37–3.85), pulmonary artery (sub-hazard ratio 1.38, 0.32–2.61), or aorto-pulmonary collateral interventions (sub-hazard ratio 1.11, 0.21–5.76). Longer post-Norwood length of stay was associated with greater risk of death/transplantation (hazard ratio 1.22 per week, 95% confidence interval 1.08–1.38), but lower risk of aorto-pulmonary collateral intervention (sub-hazard ratio 0.86 per week, 95% confidence interval 0.75–0.98). Time to pre-bidirectional Glenn catheterisation was associated with lower risk of pulmonary artery (sub-hazard ratio 0.80 per month, 95% confidence interval 0.65–0.98) and aorto-pulmonary collateral intervention (sub-hazard ratio 0.79, 0.63–0.99). Probability of moderate/severe aorto-pulmonary collateral burden increased with left-to-right shunt (22.5% at <1.0, 57.6% at >1.4) and the age at pre-bidirectional Glenn catheterisation (10.6% at <2 months, 56.9% at >5 months).

Aorto-pulmonary collateral burden is common after Norwood procedure and increases as age at bidirectional Glenn increases. As expected, higher pulmonary to systemic flow ratio is a marker for greater aorto-pulmonary collateral burden pre-bi-directional Glenn; aorto-pulmonary collateral burden does not confer risk of death/transplantation or pulmonary artery intervention.

The Residual Lesion Score is a novel tool for assessing the achievement of surgical objectives in congenital heart surgery based on widely available clinical and echocardiographic characteristics. This article describes the methodology used to develop the Residual Lesion Score from the previously developed Technical Performance Score for five common congenital cardiac procedures using the RAND Delphi methodology.

A panel of 11 experts from the field of paediatric and congenital cardiology and cardiac surgery, 2 co-chairs, and a consultant were assembled to review and comment on validity and feasibility of measuring the sub-components of intraoperative and discharge Residual Lesion Score for five congenital cardiac procedures. In the first email round, the panel reviewed and commented on the Residual Lesion Score and provided validity and feasibility scores for sub-components of each of the five procedures. In the second in-person round, email comments and scores were reviewed and the Residual Lesion Score revised. The modified Residual Lesion Score was scored independently by each panellist for validity and feasibility and used to develop the “final” Residual Lesion Score.

The Residual Lesion Score sub-components with a median validity score of ≥7 and median feasibility score of ≥4 that were scored without disagreement and with low absolute deviation from the median were included in the “final” Residual Lesion Score.

Using the RAND Delphi methodology, we were able to develop Residual Lesion Score modules for five important congenital cardiac procedures for the Pediatric Heart Network’s Residual Lesion Score study.

Systemic-to-pulmonary shunts are used as a source of pulmonary blood flow in palliated Congenital Heart Disease in neonates and young infants. Shunt thrombosis, often requiring shunt interventions during index hospitalisation, is associated with poor outcomes. We hypothesised that extensive use of perioperative pro-coagulant products may be associated with shunt thrombosis.

Children (≤18 years) undergoing systemic-to-pulmonary shunts with in-hospital shunt reinterventions between 2016 and 2020 were reviewed retrospectively. Perioperative associations to shunt thrombosis were examined by univariate logistic regression and Wilcoxon rank sum tests as appropriate. Cox and log transformed linear regression were used to analyse postoperative ventilation duration, length of stay, and cost.

Of 71 patients requiring in-hospital shunt intervention after systemic-to-pulmonary shunts, 10 (14%) had acute shunt thrombosis, and among them five (50%) died. The median age was four (interquartile range: 0-15) months. There were 40 (56%) males, 41 (58%) had single ventricle anatomy, and 29 (40%) were on preoperative anticoagulants. Patients with acute shunt thrombosis received greater volume of platelets (p = 0.04), cryoprecipitate (p = 0.02), and plasma (p = 0.04) postoperatively in the ICU; experienced more complications (p = 0.01) including re-exploration for bleeding (p = 0.008) and death (p = 0.02), had longer hospital length of stays (p = 0.004), greater frequency of other arterial/venous thrombosis (p = 0.02), and greater hospital costs (p = 0.002).

Patients who develop acute shunt thrombosis receive more blood products perioperatively and experience worse hospital outcomes and higher hospital costs. Future research on prevention/early detection of shunt thrombosis is needed to improve outcomes in infants after systemic-to-pulmonary shunt surgery.

Post-operative nausea and vomiting is frequent after congenital cardiac surgery.

We sought to determine factors associated to severe post-operative vomiting after congenital cardiac surgery and the effect on post-operative outcomes.

Patients > 30 days of age who underwent elective cardiac surgical repair as part of an enhanced recovery after congenital cardiac surgery programme were retrospectively reviewed. Patient characteristics and perioperative factors were compared by univariate analysis for patients with severe post-operative vomiting, defined as three events or more, and for patients with no-or-mild post-operative vomiting. All variables with a p-value < 0.1 were included in a multivariable model, and major post-operative outcomes were compared using regression analysis.

From 1 October, 2018 to 30 September, 2019, 430 consecutive patients were included. The median age was 4.8 years (interquartile range 1.2–12.6). Twenty-one per cent of patients (91/430) experienced severe post-operative vomiting. Total intraoperative opioids > 5.0 mg/kg of oral morphine equivalent (adjusted odds ratio 1.72) and post-operative inotropes infusion(s) (adjusted odds ratio 1.64) were identified as independent predictors of severe post-operative vomiting after surgery. Patients suffering from severe post-operative vomiting had increased pulmonary complications (adjusted odds ratio 5.18) and longer post-operative hospitalisation (adjusted coefficient, 0.89).

Greater cumulative intraoperative opioids are associated with severe post-operative vomiting after congenital cardiac surgery. Multimodal pain strategies targeting the reduction of intraoperative opioids should be considered during congenital cardiac surgery to enhance recovery after surgery.

In this era of public scrutiny, there is an ongoing need for innovative methods for patient follow-up.

As part of a quality initiative, we developed an automated post-operative follow-up system for patients following discharge after cardiac surgery at Boston Children’s Hospital.

Discharge Communication (DisCo) is a web-based system developed at Boston Children’s Hospital. An automated text and e-mail with a link to a health status survey are sent at 30 days and 1 year post-discharge in English/Spanish. If there is no response, surveys are completed via phone calls to the patient/patient’s physician or chart review. Responses are stored in the DisCo database and the patient’s medical record. Patients who underwent cardiac surgery and survived to hospital discharge from October, 2016 received the surveys.

Overall, 3345 30-day and 2563 1-year surveys were sent between October, 2016 and June, 2020. Of 3345 30-day surveys, there were 3191 responses (95%). Of 2563 1-year surveys, there were 1807 responses (71%). Most patients/families responded directly to the link at 30 days (65% for paediatrics/75% for adults) and at 1 year (72% for paediatrics/78% for adults). Multi-variable logistic regression revealed that higher complexity of cardiac lesion, presence of major non-cardiac anomalies and presence of major residua were associated with readmission and catheter/surgical reinterventions. Non-cardiac anomalies were associated with increased need for services for learning, development or behaviour.

DisCo provides a successful web-based health status assessment of patients following congenital cardiac surgery. It helps to identify high-risk patients who need closer follow-up.

Single centre retrospective cohort study of patients aged 8–18 years who underwent surgical pulmonary valve replacement. The primary predictor was preoperative percent predicted peak oxygen consumption, and primary outcome was total hospital length of stay. Clinical, imaging, and cardiopulmonary exercise test data were reviewed and compared to total hospital length of stay. Cox proportional hazards regression was used to examine the association between total hospital length of stay and percent predicted peak oxygen consumption.

Three-hundred and seventy patients undergoing pulmonary valve replacement/conduit change between 2003 and 2017 at Boston Children’s Hospital were identified. Ninety had preoperative cardiopulmonary exercise tests within 6 months of surgery. Exclusion for inadequate exercise data (n = 3) and imaging data (n = 1) left 86 patients for review. Patients with percent predicted peak oxygen consumption ≥ 70% (n = 46, 53%) had shorter total hospital length of stay (4.4 days) than the 40 with percent predicted peak oxygen consumption <70% (5.4 days, p = 0.007). Median percent predicted peak oxygen consumption increased over sequential surgical eras (p < 0.001), but total hospital length of stay did not correlate with surgical era, preoperative left ventricular function, or preoperative right ventricular dilation.

Children undergoing surgical pulmonary valve replacement with better preoperative exercise capacity had shorter total hospital length of stay. Exercise capacity is a potentially modifiable factor prior to and after pulmonary valve replacement. Until more patients systematically undergo cardiopulmonary exercise tests, the full impact of optimisation of exercise capacity will not be known.

To evaluate the discriminative ability of hyperlactataemia for early morbidity and mortality in neonates with CHD following cardiac surgery.

Retrospective, observational study of neonates who underwent cardiac surgery on cardiopulmonary bypass at a tertiary care children’s hospital from June 2015 to June 2019. The primary predictor was lactate. The primary composite outcome was defined as ≥1 of the following: cardiac arrest or extracorporeal membrane oxygenation within 72 hours or 30-day mortality post-operatively. The secondary outcome was the presence of major residual lesions, according to the Technical Performance Score.

Of 432 neonates, 28 (6.5%) sustained the composite outcome. On univariate analysis, peak lactate within 48 hours, increase in lactate from ICU admission through 12 hours, and single ventricle physiology were significantly associated with the composite outcome. The peak lactate occurred at a median of 2.9 hours (interquartile range: 1, 35) before the event. Through multi-variable analysis, a multi-variable risk algorithm was created. Predicted probabilities demonstrated an increasing risk based on single ventricle status and delta lactate, ranging from 1.8% (95% CI: 0.9, 3.9) to 52.4% (95% CI: 32.4, 71.7). The model had good discriminative ability for the composite outcome on receiver operating characteristic analysis (area under the curve = 0.79; 95% CI: 0.75, 0.89). Moreover, a peak lactate of 7.3 mmol/l or greater was significantly associated with the presence of a major residual lesion (odds ratios: 5.16, 95% CI: 3.01, 8.87).

We present a simple, two-variable model, including delta lactate in the immediate post-operative period and single ventricle status, to prognosticate the risk of early morbidity and mortality in neonates undergoing cardiac surgery for potential intervention.

Registry-based trials have emerged as a potentially cost-saving study methodology. Early estimates of cost savings, however, conflated the benefits associated with registry utilisation and those associated with other aspects of pragmatic trial designs, which might not all be as broadly applicable. In this study, we sought to build a practical tool that investigators could use across disciplines to estimate the ranges of potential cost differences associated with implementing registry-based trials versus standard clinical trials.

We built simulation Markov models to compare unique costs associated with data acquisition, cleaning, and linkage under a registry-based trial design versus a standard clinical trial. We conducted one-way, two-way, and probabilistic sensitivity analyses, varying study characteristics over broad ranges, to determine thresholds at which investigators might optimally select each trial design.

Registry-based trials were more cost effective than standard clinical trials 98.6% of the time. Data-related cost savings ranged from $4300 to $600,000 with variation in study characteristics. Cost differences were most reactive to the number of patients in a study, the number of data elements per patient available in a registry, and the speed with which research coordinators could manually abstract data. Registry incorporation resulted in cost savings when as few as 3768 independent data elements were available and when manual data abstraction took as little as 3.4 seconds per data field.

Registries offer important resources for investigators. When available, their broad incorporation may help the scientific community reduce the costs of clinical investigation. We offer here a practical tool for investigators to assess potential costs savings.

Using existing data from clinical registries to support clinical trials and other prospective studies has the potential to improve research efficiency. However, little has been reported about staff experiences and lessons learned from implementation of this method in pediatric cardiology.

We describe the process of using existing registry data in the Pediatric Heart Network Residual Lesion Score Study, report stakeholders’ perspectives, and provide recommendations to guide future studies using this methodology.

The Residual Lesion Score Study, a 17-site prospective, observational study, piloted the use of existing local surgical registry data (collected for submission to the Society of Thoracic Surgeons-Congenital Heart Surgery Database) to supplement manual data collection. A survey regarding processes and perceptions was administered to study site and data coordinating center staff.

Survey response rate was 98% (54/55). Overall, 57% perceived that using registry data saved research staff time in the current study, and 74% perceived that it would save time in future studies; 55% noted significant upfront time in developing a methodology for extracting registry data. Survey recommendations included simplifying data extraction processes and tailoring to the needs of the study, understanding registry characteristics to maximise data quality and security, and involving all stakeholders in design and implementation processes.

Use of existing registry data was perceived to save time and promote efficiency. Consideration must be given to the upfront investment of time and resources needed. Ongoing efforts focussed on automating and centralising data management may aid in further optimising this methodology for future studies.

Following stage 1 palliation, delayed sternal closure may be used as a technique to enhance thoracic compliance but may also prolong the length of stay and increase the risk of infection.

We reviewed all neonates undergoing stage 1 palliation at our institution between 2010 and 2017 to describe the effects of delayed sternal closure.

During the study period, 193 patients underwent stage 1 palliation, of whom 12 died before an attempt at sternal closure. Among the 25 patients who underwent primary sternal closure, 4 (16%) had sternal reopening within 24 hours. Among the 156 infants who underwent delayed sternal closure at 4 [3,6] days post-operatively, 11 (7.1%) had one or more failed attempts at sternal closure. Patients undergoing primary sternal closure had a shorter duration of mechanical ventilation and intensive care unit length of stay. Patients who failed delayed sternal closure had a longer aortic cross-clamp time (123±42 versus 99±35 minutes, p=0.029) and circulatory arrest time (39±28 versus 19±17 minutes, p=0.0009) than those who did not fail. Failure of delayed sternal closure was also closely associated with Technical Performance Score: 1.3% of patients with a score of 1 failed sternal closure compared with 18.9% of patients with a score of 3 (p=0.0028). Among the haemodynamic and ventilatory parameters studied, only superior caval vein saturation following sternal closure was different between patients who did and did not fail sternal closure (30±7 versus 42±10%, p=0.002). All patients who failed sternal closure did so within 24 hours owing to hypoxaemia, hypercarbia, or haemodynamic impairment.

When performed according to our current clinical practice, sternal closure causes transient and mild changes in haemodynamic and ventilatory parameters. Monitoring of SvO2 following sternal closure may permit early identification of patients at risk for failure.