High Acuity Therapy Variation Across Pediatric Acute Care Cardiology Units: Results from the Pediatric Acute Care Cardiology Collaborative Hospital Surveys.

We utilized the multicenter Pediatric Acute Care Cardiology Collaborative (PAC3) 2017 and 2019 surveys to describe practice variation in therapy availability and changes over a 2-year period. A high acuity therapies (ATs) score was derived (1 point per positive response) from 44 survey questions and scores were compared to center surgical volume. Of 31 centers that completed the 2017 survey, 26 also completed the 2019 survey. Scores ranged from 11 to 34 in 2017 and 11 to 35 in 2019. AT scores in 2019 were not statistically different from 2017 scores (29/44, IQR 27-32.5 vs. 29.5/44, IQR 27-31, p = 0.9). In 2019, more centers reported initiation of continuous positive airway pressure (CPAP) and Bi-level positive airway pressure (BiPAP) in Acute Care Cardiology Unit (ACCU) (19/26 vs. 4/26, p < 0.001) and permitting continuous CPAP/BiPAP (22/26 vs. 14/26, p = 0.034) compared to 2017. Scores in both survey years were significantly higher in the highest surgical volume group compared to the lowest, 33 ± 1.5 versus 25 ± 8.5, p = 0.046 and 32 ± 1.7 versus 23 ± 5.5, p = 0.009, respectively. Variation in therapy within the ACCUs participating in PAC3 presents an opportunity for shared learning across the collaborative. Experience with PAC3 was associated with increasing available respiratory therapies from 2017 to 2019. Whether AT scores impact the quality and outcomes of pediatric acute cardiac care will be the subject of further investigation using a comprehensive registry launched in early 2019.

Intensive Care Unit and Acute Care Unit Length of Stay After Congenital Heart Surgery.

BACKGROUND: Postoperative length of stay (LOS) is an important quality metric and is known to vary widely across hospitals after congenital heart surgery. Whether this variability is explained by factors associated with the intensive care unit (ICU) or acute care unit (ACU) remains unclear. We evaluated the relationship between ICU and ACU LOS and the impact of ACU characteristics on postoperative LOS. METHODS: Hospitalizations for congenital heart surgery within the Pediatric Cardiac Critical Care Consortium (PC4) registry (August 2014 to February 2018) were included. Models were developed for ICU, ACU, and postoperative LOS by adjusting for differences in case-mix across hospitals. PC4 hospitals participating in the Pediatric Acute Care Cardiology Collaborative (PAC3) were also surveyed on ACU organizational factors and practice patterns. RESULTS: Overall, 19,674 hospitalizations across 27 hospitals were included. There was significant variation in ICU and ACU LOS. Postperative LOS appeared to be most closely related to ICU LOS; 75% (6 of 8) of hospitals with shorter than expected postoperative LOS also had shorter than expected ICU LOS. A clear relationship between postoperative and ACU LOS was not observed. Hospitals with an ACU able to provide higher-acuity care as indexed according to the PAC3 survey were more likely to have shorter postoperative LOS (P < .01). CONCLUSIONS: For hospitals that achieve shorter than expected postoperative LOS after congenital heart surgery, ICU LOS appears to be the primary driver. Higher-acuity resources in the ACU may be an important factor facilitating earlier transfer from the ICU. These data are key to informing quality improvement initiatives geared toward reducing postoperative LOS.

Is Clinic Visit Frequency Associated with Weight Gain During the Interstage Period? A Report from the Joint Council on Congenital Heart Disease National Pediatric Cardiology Quality Improvement Collaborative (JCCHD-NPCQIC).

Growth problems are prevalent among infants with congenital heart disease. We sought to determine whether frequency of outpatient clinic visits correlated with weight gain in patients with hypoplastic left heart syndrome or variant during the interstage period between discharge from stage I palliation and presentation for stage II palliation (SIIP). Using prospectively collected data from the JCCHD NPC-QIC database from June 2008 to July 2013, we performed a retrospective cohort study assessing the association of days between clinic visits (DBV) with the change in weight-for-age z-score (WAZ) during the interstage period. Eligible subjects were those who survived to a SIIP performed at <270 days of age and had at least two outpatient clinic visits. There were 561 patients from 49 centers who fulfilled inclusion criteria. The average interstage change in WAZ was +0.22. The mean number of DBV was 16.1 days, and the average number of clinic visits was six. There was no correlation of change in WAZ with either DBV (r = 0.02, P = 0.62) or the number of visits (r = 0.03, P = 0.44). Subjects within this cohort are seen about every 2 weeks averaged over the interstage period. There is no correlation between interstage visit frequency and change in WAZ in this patient population. Further research is needed to describe differences in visit frequency as the patient progresses through the interstage period and to elucidate whether patient factors such as growth velocity are influencing visit frequency. The optimal visit frequency remains unknown.

Longitudinal assessment of growth in hypoplastic left heart syndrome: results from the single ventricle reconstruction trial.

BACKGROUND: We sought to characterize growth between birth and age 3 years in infants with hypoplastic left heart syndrome who underwent the Norwood procedure. METHODS AND RESULTS: We performed a secondary analysis using the Single Ventricle Reconstruction Trial database after excluding patients <37 weeks gestation (N=498). We determined length-for-age z score (LAZ) and weight-for-age z score (WAZ) at birth and age 3 years and change in WAZ over 4 clinically relevant time periods. We identified correlates of change in WAZ and LAZ using multivariable linear regression with bootstrapping. Mean WAZ and LAZ were below average relative to the general population at birth (P<0.001, P=0.05, respectively) and age 3 years (P<0.001 each). The largest decrease in WAZ occurred between birth and Norwood discharge; the greatest gain occurred between stage II and 14 months. At age 3 years, WAZ and LAZ were <-2 in 6% and 18%, respectively. Factors associated with change in WAZ differed among time periods. Shunt type was associated with change in WAZ only in the Norwood discharge to stage II period; subjects with a Blalock-Taussig shunt had a greater decline in WAZ than those with a right ventricle-pulmonary artery shunt (P=0.002). CONCLUSIONS: WAZ changed over time and the predictors of change in WAZ varied among time periods. By age 3 years, subjects remained small and three times as many children were short as were underweight (>2 SD below normal). Failure to find consistent risk factors supports the strategy of tailoring nutritional therapies to patient- and stage-specific targets. CLINICAL TRIAL REGISTRATION URL: http://clinicaltrials.gov/. Unique identifier: NCT00115934.

Heterotaxy syndrome and malrotation: does isomerism influence risk and decision to treat.

PURPOSE: Controversy remains regarding the management of the asymptomatic heterotaxy syndrome (HS) patient with suspected intestinal rotational abnormalities. We evaluated the outcomes for our HS population to identify frequency of malrotation and identify characteristics of children who might benefit from expectant management. METHODS: After IRB approval, a retrospective review of all patients treated for HS at a large tertiary care children's hospital between January 2008 and June 2012 was performed. For the purpose of this paper, malrotation was defined as an operative note that described the presence of Ladd's bands and a narrow mesentery. RESULTS: Thirty-eight patients with HS were identified, including 18 who underwent abdominal exploration. Left atrial isomerisation (LAI) was identified in 13 individuals, and right atrial isomerisation (RAI) was noted in 25. The rate of surgical intervention did not vary between the 2 groups (54%). Malrotation was found in 8 patients: one with LAI and 7 with RAI. This difference in incidence was statistically significant (p=0.04). CONCLUSION: These data suggest that the direction of atrial isomerisation influences the likelihood of true malrotation, where RAI patients are more likely to be malrotated. Given the inherent risk of surgery on this medically fragile patient population, surgeons should consider expectant management for asymptomatic LAI patients.

Is there a benefit to postoperative fluid restriction following infant surgery?

OBJECTIVE: Fluid restriction is often employed immediately following cardiac surgery in children. The goal of this approach is to achieve an early negative fluid balance, which theoretically should lead to less interstitial edema and earlier extubation. The purpose of this study was to determine whether time to negative fluid balance in infants after undergoing systemic-to-pulmonary artery shunt palliation impacts duration of mechanical ventilation and hospital length of stay. DESIGN: This is a retrospective study of neonates who underwent a modified systemic-to-pulmonary artery shunt at a single institution. SETTING: University hospital pediatric cardiac intensive care unit (CICU). PATIENTS: Neonates who underwent a modified systemic-to-pulmonary artery shunt between January 1, 2009 and June 1, 2011. OUTCOME MEASURES: Information collected included time to negative fluid balance (in hours), CICU and hospital length of stay (in days), and the number of patients who had delayed sternal closure and/or underwent cardiopulmonary bypass. RESULTS: Data were available for 65 subjects. Median fluid administration in the 24 hours postoperatively was 43.9 cc/kg/day (interquartile range: 32.9-61.0). Mean time to negative fluid balance was 25.0 ± 12.8 hours. Time to negative fluid balance was not associated with time to extubation, CICU and hospital length of stay, or change in weight-for-age z-score at intensive care unit discharge. CONCLUSION: Time to negative fluid balance is not associated with duration of mechanical ventilation, CICU, and hospital length of stay in patients after undergoing systemic-to-pulmonary artery shunt palliation. The utility of a restricted fluid strategy immediately following infant heart surgery is questionable.

Variation in feeding practices following the Norwood procedure.

OBJECTIVES: To assess variation in feeding practice at hospital discharge after the Norwood procedure, factors associated with tube feeding, and associations among site, feeding mode, and growth before stage II. STUDY DESIGN: From May 2005 to July 2008, 555 subjects from 15 centers were enrolled in the Pediatric Heart Network Single Ventricle Reconstruction Trial; 432 survivors with feeding data at hospital discharge after the Norwood procedure were analyzed. RESULTS: Demographic and clinical variables were compared among 4 feeding modes: oral only (n = 140), oral/tube (n = 195), nasogastric tube (N-tube) only (n = 40), and gastrostomy tube (G-tube) only (n = 57). There was significant variation in feeding mode among sites (oral only 0%-81% and G-tube only 0%-56%, P < .01). After adjusting for site, multivariable modeling showed G-tube feeding at discharge was associated with longer hospitalization, and N-tube feeding was associated with greater number of discharge medications (R(2) = 0.65, P < .01). After adjusting for site, mean pre-stage II weight-for-age z-score was significantly higher in the oral-only group (-1.4) vs the N-tube-only (-2.2) and G-tube-only (-2.1) groups (P = .04 and .02, respectively). CONCLUSIONS: Feeding mode at hospital discharge after the Norwood procedure varied among sites. Prolonged hospitalization and greater number of medications at the time of discharge were associated with tube feeding. Infants exclusively fed orally had a higher weight-for-age z score pre-stage II than those fed exclusively by tube. Exploring strategies to prevent morbidities and promote oral feeding in this highest risk population is warranted.

Patient and practice factors affecting growth of infants with systemic-to-pulmonary shunt.

BACKGROUND: On recognising poor growth following neonatal palliation with a systemic-to-pulmonary shunt, we sought to determine how patient- and procedure-related factors impact growth, paying attention to the role of the primary cardiologist in this process. METHODS: In a retrospective review, neonates (133 patients) receiving modified systemic-to-pulmonary artery shunts from 2002 to 2009 were studied and outpatient visits were reviewed. Patients with single- and two-ventricle circulations after shunt takedown were compared using weight-for-age z-score. RESULTS: Single-ventricle patients had a higher weight-for-age z-score at neonatal surgery than two-ventricle patients (-0.4 ± 1.0 compared with -1.2 ± 0.9, with p < 0.001), but they had a greater drop in the weight-for-age z-score to the first outpatient visit (-1.1 ± 0.7 compared with -0.8 ± 0.7, with p = 0.02). After the first outpatient visit, the weight-for-age z-score was not significantly different between single-ventricle and two-ventricle patients. From multivariate analysis, a lower number of nutritional interventions by cardiologists was significantly associated with poor growth (p = 0.03). Poor growth was not associated with race, use of feeding tube, exclusive formula use, or proximity to surgical centre. CONCLUSION: The significant drop in the weight-for-age z-score from neonatal surgery to first outpatient visit suggests that these patients may receive inadequate nutrition. The poorest performers received the least number of outpatient changes to their diet. This finding underscores the critical role of the primary cardiologist in optimising weight gain through adjustments in nutrition.

Caloric intake during the perioperative period and growth failure in infants with congenital heart disease.

Infants with congenital heart disease have impaired weight gain during the first several months of life. Efforts have focused on improving weight gain and nutritional status during the first months of life. Close examination of the data suggests that the immediate postoperative period is problematic. Etiology of this early growth failure should be identified to develop effective interventions. This is a retrospective study of neonates who underwent modified systemic-to-pulmonary artery shunt, including Norwood palliation, at Children's Healthcare of Atlanta between January 2009 and July 2011. We analyzed growth from time of surgical intervention to hospital discharge. Measures of calculated weight-for-age Z-score (WAZ score) were performed using the World Health Organization's Anthro Software (version 3.2.2, January 2011; WHO, Geneva, Switzerland). Seventy-three patients were identified. Eight patients did not meet inclusion criteria. Complete data were collected on the remaining 65 patients. Median caloric intake patients received was 50.4 [interquartile range (IQR) 41.6 to 63.6] calories/kg/day while exclusively on parental nutrition. At hospital discharge, the median WAZ score was -2.0 (IQR -2.7 to -1.2) representing an overall median WAZ score decrease of -1.3 (IQR -1.7 to -0.7) from time of shunt palliation to hospital discharge. Despite studies showing poor weight gain in infants with congenital heart disease after neonatal palliation, this study reports the impact of hospital-based nutritional practices on weight gain in infants during the immediate postoperative period. Our data demonstrate that actual caloric intake during the cardiac intensive care unit stay is substantially below what is recommended.

Coarctation of the aorta in the setting of tetralogy of Fallot: an uncommon cause of myocardial dysfunction.

The combination of both right and left heart obstruction has only rarely been described in the medical literature. We present three cases of coarctation of the aorta in patients with variants of tetralogy of Fallot and hypothesise that this condition may be more common than previously suspected and could represent a hidden cause of morbidity in patients with pulmonary atresia/ventricular septal defect.

Interstage mortality after the Norwood procedure: Results of the multicenter Single Ventricle Reconstruction trial.

OBJECTIVE: For infants with single ventricle malformations undergoing staged repair, interstage mortality is reported at 2% to 20%. The Single Ventricle Reconstruction trial randomized subjects with a single morphologic right ventricle undergoing a Norwood procedure to a modified Blalock-Taussig shunt (MBTS) or a right ventricle-to-pulmonary artery shunt (RVPAS). The aim of this analysis was to explore the associations of interstage mortality and shunt type, and demographic, anatomic, and perioperative factors. METHODS: Participants in the Single Ventricle Reconstruction trial who survived to discharge after the Norwood procedure were included (n = 426). Interstage mortality was defined as death postdischarge after the Norwood procedure and before the stage II procedure. Univariate analysis and multivariable logistic regression were performed adjusting for site. RESULTS: Overall interstage mortality was 50 of 426 (12%)-13 of 225 (6%) for RVPAS and 37 of 201 (18%) for MBTS (odds ratio [OR] for MBTS, 3.4; P < .001). When moderate to severe postoperative atrioventricular valve regurgitation (AVVR) was present, interstage mortality was similar between shunt types. Interstage mortality was independently associated with gestational age less than 37 weeks (OR, 3.9; P = .008), Hispanic ethnicity (OR, 2.6; P = .04), aortic atresia/mitral atresia (OR, 2.3; P = .03), greater number of post-Norwood complications (OR, 1.2; P = .006), census block poverty level (P = .003), and MBTS in subjects with no or mild postoperative AVVR (OR, 9.7; P < .001). CONCLUSIONS: Interstage mortality remains high at 12% and is increased with the MBTS compared with the RVPAS if postoperative AVVR is absent or mild. Preterm delivery, anatomic, and socioeconomic factors are also important. Avoiding preterm delivery when possible and close surveillance after Norwood hospitalization for infants with identified risk factors may reduce interstage mortality.

Association of feeding modality with interstage mortality after single-ventricle palliation.

OBJECTIVE: Interstage mortality has been reported in 10% to 25% of hospital survivors after single-ventricle palliation. The purpose of this study was to examine the impact of feeding modality at discharge after single-ventricle palliation on interstage mortality. METHODS: We conducted a retrospective review of all neonates undergoing single-ventricle palliation from January 2003 to January 2010. A total of 334 patients (90%) survived to hospital discharge, comprising the study group. Preoperative, operative, and postoperative variables were examined, including feeding method at discharge. Multivariate Poisson regression models were constructed to estimate the relative risk of interstage mortality. RESULTS: Of 334 patients, 56 (17%) underwent gastrostomy tube ± Nissen. There was a statistically significant increase in interstage mortality for patients who underwent gastrostomy tube ± Nissen compared with patients who did not (relative risk, 2.38; 95% confidence interval, 1.05-5.40; P = .04]). Of the 278 patients who were not fed via a gastrostomy tube ± Nissen, 190 (68%) were fed with nasogastric feedings and 88 (32%) were fed entirely by mouth. There was no difference in interstage mortality between these 2 groups (relative risk, 0.92; 95% confidence interval, 0.31-2.73; P = .89). CONCLUSIONS: Neonates undergoing single-ventricle palliation who require gastrostomy tube ± Nissen are at an increased risk of interstage mortality. The need for gastrostomy tube ± Nissen in this population may be a marker for other unmeasured comorbidities that place them at an increased risk of interstage mortality. Discharge with nasogastric feeds does not increase the risk of interstage mortality.

Gastric fundoplication is effective in promoting weight gain in children with severe congenital heart defects.

AIM: The aim of this study was to determine outcomes, including weight gain, morbidity, and mortality, of children with severe congenital heart disease who underwent fundoplication (FP) for gastroesophageal reflux disease. METHODS: An institutional review board-approved retrospective review was conducted on all children with congenital heart disease who underwent FP from 1999 to 2005. Preoperative age, weight, cardiac procedures, postoperative weight, and mortality were extracted from medical records. The Wilcoxon signed rank, Wilcoxon rank sum, and log-rank tests were used; P value less than .05 was significant. All procedures were performed with dedicated cardiac anesthesia personnel with recovery in a cardiac intensive care unit. RESULTS: Of 112 subjects identified, 37 (33%) had single ventricle (SV) physiology. The most frequent cardiac procedures performed were Norwood (33), pulmonary artery band (11), and systemic pulmonary artery shunt (11). A total of 104 laparoscopic FPs (with 2 conversions to open) and 8 open FPs were performed. The median preoperative age was 3 months, and weight percentile was 1.5%. From baseline, postoperative median weight percentiles increased to 4% at 3 months (P < .001) and to 20% at 5 years postoperatively (P = .004). Single ventricle physiology had no significant effect on outcomes. Postoperative mortality (< or =30 days) was 4.5% (5/112); 5-year survival was 74% (83/112). Five-year survival of SV subjects (59%) was significantly lower (P = .03) than that of the other subjects (81%). No significant difference in survival was seen between SV subjects with FP and all SV patients seen at our center during the study period. Only one death was directly related to antireflux surgery (SV subject). There were 8 patients who had recurrent gastroesophageal reflux disease: 4 were treated with reoperation, and 4 were treated medically. CONCLUSION: Weight gain in this high-risk population can be expected after antireflux surgery. Mortality is high because of intrinsic disease, especially in the SV population. Fundoplications performed with the assistance of dedicated pediatric cardiac anesthesia personnel followed by recovery in a cardiac intensive care unit is possible with acceptable postoperative morbidity and mortality.

Routine immunizations and adverse events in infants with single-ventricle physiology.

BACKGROUND: Infants with single-ventricle congenital heart defects are at risk of sudden unexpected death. In an effort to decrease the risk of sudden death, some centers have advocated that routine immunizations be deferred in this population. However, it is not known if an association exists between immunizations and adverse events. METHODS: The present study examined the relationship of routine immunizations with adverse events, which were defined as sudden death or hospital readmission. The diphtheria-tetanus-acellular pertussis (DTaP) vaccine was considered in the analysis. The patient population consisted of infants younger than 9 months old who resided locally and had not yet undergone bidirectional cavopulmonary anastomosis (BCPA). Immunization data were obtained from a mandatory statewide database. RESULTS: During a 35-month period, 137 patients with single-ventricle physiology were discharged home after neonatal surgery or directly from the newborn nursery. Hypoplastic left heart syndrome (HLHS) was the diagnosis in 58 patients (42%) and was the most common. In the entire cohort, there were four sudden deaths (3%), and 53 patients (38%) had at least one interval hospital admission. Immunization within 48 hours was not associated with adverse events (odds ratio, 1.48; 95% confidence interval, 0.73 to 2.90; p = 0.31). No sudden death events occurred within 48 hours of immunization. CONCLUSIONS: No association could be identified between routine immunizations and adverse events in infants with single-ventricle physiology. As such, the proposal to alter the immunization regimen in this population does not appear justified.

Freedom from neoaortic insufficiency: a comparison of classic Norwood and Norwood-Sano procedures.

OBJECTIVES: To investigate the incidence of neoaortic insufficiency in patients with hypoplastic left heart syndrome treated with the Norwood-Sano palliation and to compare it with that occurring after the classic Norwood procedure. DESIGN, SETTING, PATIENTS, INTERVENTIONS: This was a retrospective review of all echocardiograms of patients diagnosed with hypoplastic left heart syndrome (concomitant presence of left ventricular and aortic and mitral severe hypoplasia or atresia) who underwent staged palliation of the Norwood or Norwood-Sano type at a single academic institution between September 1999 and February 2005 and who survived a minimum of 3 months. OUTCOME MEASURES: Neoaortic insufficiency was categorized as absent or mild <1 mm jet width, moderate 1-3 mm jet width, or severe >3 mm jet width. The patients were grouped according to initial palliation, that is, classic Norwood and Norwood-Sano operation. RESULTS: Fifty-nine consecutive patients (median age of 20 months with a range from 3 to 66 months) satisfied inclusion criteria. Neoaortic insufficiency was absent or mild in 55 of 59 (93.22%) of the patients. There were 4 cases of significant neoaortic insufficiency at late follow-up: 2 moderate following the classic Norwood and 1 moderate and 1 severe following the Norwood-Sano procedure, one of whom required valve replacement. CONCLUSIONS: In this series of patients with hypoplastic left heart syndrome, the Sano modification was not associated with an increased incidence of significant neoaortic insufficiency. When present, moderate/severe neoaortic insufficiency appeared late after initial palliation and was associated with recurrent ascending aortic or aortic arch pathology in every case.

Retinoid X receptor alpha represses GATA-4-mediated transcription via a retinoid-dependent interaction with the cardiac-enriched repressor FOG-2.

Dietary vitamin A and its derivatives, retinoids, regulate cardiac growth and development. To delineate mechanisms involved in retinoid-mediated control of cardiac gene expression, the regulatory effects of the retinoid X receptor alpha (RXR alpha) on atrial naturietic factor (ANF) gene transcription was investigated. The transcriptional activity of an ANF promoter-reporter in rat neonatal ventricular myocytes was repressed by RXR alpha in the presence of 9-cis-RA and by the constitutively active mutant RXR alpha F318A indicating that liganded RXR confers the regulatory effect. The RXR alpha-mediated repression mapped to the proximal 147 bp of the rat ANF promoter, a region lacking a consensus retinoid response element but containing several known cardiogenic cis elements including a well characterized GATA response element. Glutathione S-transferase "pull-down" assays revealed that RXR alpha interacts directly with GATA-4, in a ligand-independent manner, via the DNA binding domain of RXR alpha and the second zinc finger of GATA-4. Liganded RXR alpha repressed the activity of a heterologous promoter-reporter construct containing GATA-response element recognition sites in cardiac myocytes but not in several other cell types, suggesting that additional cardiac-enriched factors participate in the repression complex. Co-transfection of liganded RXR alpha and the known cardiac-enriched GATA-4 repressor, FOG-2, resulted in additive repression of GATA-4 activity in ventricular myocytes. In addition, RXR alpha was found to bind FOG-2, in a 9-cis-RA-dependent manner. These data reveal a novel mechanism by which retinoids regulate cardiogenic gene expression through direct interaction with GATA-4 and its co-repressor, FOG-2.