PRIMARY HYPOTHESIS: We hypothesized that higher alveolar dead space fraction (AVDSf) at pediatric acute respiratory distress syndrome (PARDS) onset would be associated with right ventricular (RV) systolic dysfunction within the first 24 h of PARDS.

STUDY DESIGN AND METHODS: We performed a retrospective single-center cohort study of PARDS patients with clinically obtained echocardiograms within 24 h. Primary exposure was AVDSf at PARDS onset. Primary outcome was RV systolic dysfunction as defined by RV global longitudinal strain (GLS) (>-18%). Secondary outcomes included pulmonary hypertension (PH) and RV systolic dysfunction as defined by other echocardiogram parameters, and measures of oxygenation. Unadjusted and adjusted logistic and linear regression were used to investigate AVDSf associations with outcomes.

RESULTS: Ninety-one patients were included: median age 6.2 years, 46% female, and 65% with moderate or severe PARDS. Median AVDSf was 0.2 (interquartile range [IQR] 0.0-0.3), 33% had RV dysfunction, and 21% had PH. Unadjusted and adjusted logistic regression showed no association between AVDSf and RV systolic dysfunction or PH by any echocardiographic measure, but unadjusted and adjusted linear regression did show an association between AVDSf and PaO /FiO .

CONCLUSION: AVDSf at PARDS onset was not associated with RV systolic dysfunction or PH within 24 h but was associated with PaO /FiO ratio and may be more reflective of pulmonary causes of ventilation-perfusion mismatch. Future investigations should focus on clarifying the clinical utility of AVDSf in relation to existing metrics throughout the course of PARDS.

BACKGROUND: There is ongoing debate about the best strategy to treat patients with tetralogy of Fallot who are symptomatic in the neonatal period.

OBJECTIVES: The aim of this study was to compare the outcomes of complete versus staged surgery (i.e., initial palliative procedure for possible later complete repair).

METHODS: A retrospective cohort study was performed using the Pediatric Health Information System database, including patients who underwent complete or staged tetralogy of Fallot repair prior to 30 days of age. The primary outcome was death during 2-year follow-up after the initial procedure. Inverse probability-weighted Cox and logistic regression models were used to examine the association between surgical approach group and mortality while accounting for patient- and hospital-level factors. Causal mediation analyses examined the role of intermediate variables.

RESULTS: A total of 2,363 patients were included (1,032 complete and 1,331 staged). There were 239 deaths. Complete neonatal repair was associated with a significantly higher risk for mortality during the 2-year follow-up period (hazard ratio: 1.51; 95% confidence interval: 1.05 to 2.06), between 7 and 30 days after the initial procedure (hazard ratio: 2.29; 95% confidence interval: 1.18 to 4.41), and during the initial hospital admission (odds ratio: 1.72; 95% confidence interval: 1.15 to 2.62). Post-operative cardiac complications were more common in the complete repair group and mediated the differences in 30-day and 2-year mortality.

CONCLUSIONS: Complete surgical repair for neonates with tetralogy of Fallot is associated with a significantly higher risk for early and 2-year mortality compared with the staged approach, after accounting for patient and hospital characteristics. Post-operative cardiac complications mediated these findings.

<p>BACKGROUND Children with single ventricle heart disease have significant morbidity and mortality. The maternal-fetal environment (MFE) may adversely impact outcomes after neonatal cardiac surgery. We hypothesized that impaired MFE would be associated with an increased risk of death after stage 1 Norwood reconstruction. METHODS AND RESULTS We performed a retrospective cohort study of children with hypoplastic left heart syndrome (and anatomic variants) who underwent stage 1 Norwood reconstruction between 2008 and 2018. Impaired MFE was defined as maternal gestational hypertension, preeclampsia, gestational diabetes, and/or smoking during pregnancy. Cox proportional hazards regression models were used to investigate the association between impaired MFE and death while adjusting for confounders. Hospital length of stay was assessed with the competing risk of in-hospital death. In 273 children, the median age at stage 1 Norwood reconstruction was 4&nbsp;days (interquartile range [IQR], 3-6 days). A total of 72 children (26%) were exposed to an impaired MFE; they had more preterm births (18% versus 7%) and a greater percentage with low birth weights &lt;2.5&nbsp;kg (18% versus 4%) than those without impaired MFE. Impaired MFE was associated with a higher risk of death (hazard ratio [HR], 6.05; 95% CI, 3.59-10.21; &lt;0.001) after adjusting for age at surgery, Hispanic ethnicity, genetic syndrome, cardiac diagnosis, surgeon, and birth era. Children with impaired MFE had almost double the risk of prolonged hospital stay (HR, 1.95; 95% CI, 1.41-2.70; &lt;0.001). CONCLUSIONS Children exposed to an impaired MFE had a higher risk of death following stage 1 Norwood reconstruction. Prenatal exposures are potentially modifiable factors that can be targeted to improve outcomes after pediatric cardiac surgery.</p>

<p>Tetralogy of Fallot (TOF) repair is associated with excellent operative survival. However, a subset of patients experiences post-operative complications, which can significantly alter the early and late post-operative course. We utilized a machine learning approach to identify risk factors for post-operative complications after TOF repair. We conducted a single-center prospective cohort study of children &lt;2 years of age with TOF undergoing surgical repair. The outcome was occurrence of post-operative cardiac complications, measured between TOF repair and hospital discharge or death. Predictors included patient, operative, and echocardiographic variables, including pre-operative right ventricular strain and fractional area change as measures of right ventricular function. Gradient-boosted quantile regression models (GBM) determined predictors of post-operative complications. Cross-validated GBMs were implemented with and without a filtering stage non-parametric regression model to select a subset of clinically meaningful predictors. Sensitivity analysis with gradient-boosted Poisson regression models was used to examine if the same predictors were identified in the subset of patients with at least one complication. Of the 162 subjects enrolled between March 2012 and May 2018, 43 (26.5%) had at least one post-operative cardiac complication. The most frequent complications were arrhythmia requiring treatment ( = 22, 13.6%), cardiac catheterization ( = 17, 10.5%), and extracorporeal membrane oxygenation (ECMO) ( = 11, 6.8%). Fifty-six variables were used in the machine learning analysis, of which there were 21 predictors that were already identified from the first-stage regression. Duration of cardiopulmonary bypass (CPB) was the highest ranked predictor in all models. Other predictors included gestational age, pre-operative right ventricular (RV) global longitudinal strain, pulmonary valve Z-score, and immediate post-operative arterial oxygen level. Sensitivity analysis identified similar predictors, confirming the robustness of these findings across models. Cardiac complications after TOF repair are prevalent in a quarter of patients. A prolonged surgery remains an important predictor of post-operative complications; however, other perioperative factors are likewise important, including pre-operative right ventricular remodeling. This study identifies potential opportunities to optimize the surgical repair for TOF to diminish post-operative complications and secure improved clinical outcomes. Efforts toward optimizing pre-operative ventricular remodeling might mitigate post-operative complications and help reduce future morbidity.</p>

<p><strong>Background </strong>Risk-adjusted adverse event (AE) rates have been used to measure the quality of pediatric and congenital cardiac catheterization laboratories. In other settings, failure to rescue (FTR) has demonstrated utility as a quality metric.</p>

<p><strong>Methods and Results </strong>A multicenter retrospective cohort study was performed using data from the IMPACT (Improving Adult and Congenital Treatment) Registry between January 2010 and December 2016. A modified FTR metric was developed for pediatric and congenital cardiac catheterization laboratories and then compared with pooled AEs. The associations between patient- and hospital-level factors and outcomes were evaluated using hierarchical logistic regression models. Hospital risk standardized ratios were then calculated. Rankings of risk standardized ratios for each outcome were compared to determine whether AEs and FTR identified the same high- and low-performing centers. During the study period, 77&nbsp;580 catheterizations were performed at 91 hospitals. Higher annual hospital catheterization volume was associated with lower odds of FTR (odds ratio: 0.68 per 300 cases; =0.0003). No association was seen between catheterization volume and odds of AEs. Odds of AEs were instead associated with patient- and procedure-level factors. There was no correlation between risk standardized ratio ranks for FTR and pooled AEs (=0.46). Hospital ranks by catheterization volume and FTR were associated (=-0.28, =0.01) with the largest volume hospitals having the lowest risk of FTR.</p>

<p><strong>Conclusions</strong> In contrast to AEs, FTR was not strongly associated with patient- and procedure-level factors and was significantly associated with pediatric and congenital cardiac catheterization laboratory volume. Hospital rankings based on FTR and AEs were not significantly correlated. We conclude that FTR is a complementary measure of catheterization laboratory quality and should be included in future research and quality-improvement projects.</p>

<p>Background Cardiac catheterization is an important but costly component of health care for young patients with cardiac disease. Measurement of variation in their cost between hospitals and identification of the reasons for this variation may help reduce cost without compromising quality. Methods and Results Using data from Pediatric Health Information Systems Database from January 2007 to December 2015, the costs of 9 procedures were measured. Mixed-effects multivariable models were used to generate case-mix-adjusted estimates of each hospital's cost for each procedure and measure interhospital variation. Procedures (n=35&nbsp;637) from 43 hospitals were studied. Median costs varied from $8249 (diagnostic catheterization after orthotopic heart transplantation) to $38&nbsp;909 (transcatheter pulmonary valve replacement). There was marked variation in the cost of procedures between hospitals with 3.5- to 8.9-fold differences in the case-mix-adjusted cost between the most and least expensive hospitals. No significant correlation was found between hospitals' procedure-specific mortality rates and costs. Higher procedure volume was not associated with lower cost except for diagnostic procedures in heart transplant patients and pulmonary artery angioplasty. At the hospital level, the proportion of cases that were outliers (&gt;95th percentile) was significantly associated with rank in terms of cost (Spearman's ρ ranging from 0.37 to 0.89, P&lt;0.01). Conclusions Large-magnitude hospital variation in cost was not explained by case-mix or volume. Further research is necessary to determine the degree to which variation in cost is the result of differences in the efficiency of the delivery of healthcare services and the rate of catastrophic adverse outcomes and resultant protracted and expensive hospitalizations.</p>