The Alberta Infant Motor Scale as an Outcomes Measure of Gross Motor Abilities after Early Complex Cardiac Surgery.

To address the research hypothesis that the Alberta Infant Motor Scale (AIMS) completed following complex cardiac surgery (CCS) is a useful outcomes measure this study determined: (1) AIMS scores at age 8 months after CCS; (2) predictive validity of AIMS at 8 months for Bayley Scales of Infant and Toddler Development-III Gross Motor-scaled scores (GMSS) and diagnosis of cerebral palsy (CP) at 21 months; and (3) predictive demographic and surgical variables of AIMS scores. A prospective cohort study of 250/271 (92.3%) surviving children from Northern Alberta (born 2009-2020) who had CCS at age < 6 months determined AIMS scores at age mean (SD) 8.6 (2.4) and the GMSS at 21.9 (3.8) months. Gross motor delay was defined as AIMS < 5th percentile and GMSS as < 4 (-2SD). Predictions using multiple logistic regressions were expressed as Odds Ratios (OR) and 95% Confidence Interval (CI). Of children, 100/250 (40%) had AIMS < 5th predicting GMSS < 4 (n = 43); sensitivity, specificity, positive, and negative predictive values were 88%, 71%, 40%, and 97%. Hospitalization days were independently associated with AIMS < 5th, OR 1.02 (95% CI 1.007, 1.032; p = 0.005). Excluding hospital days, ventilation days independently predicted AIMS < 5th, OR 1.08 (95% CI 1.038, 1.125, p < 0.001. Gross motor delay determine by AIMS scores of < 5th percentile occurred in 40% of survivors with good prediction of continued delay. Delay determined by AIMS was predicted by longer hospitalization and ventilation; further investigations about the causes are required. AIMS results provide opportunity for early motor intervention.

Differences in gross motor and fine motor outcomes for toddlers after early complex cardiac surgery.

OBJECTIVES: To determine whether gross motor scores of toddlers after complex cardiac surgery were different from fine motor scores and were adequately represented by motor composite scores and, whether acute care predictors and chronic childhood health markers of gross motor scores differed from those of fine motor. METHODS: This prospective inception-cohort outcomes study included 171 toddlers after complex cardiac surgery with cardiopulmonary bypass at age <6 months, born in Northern Alberta from 2009 to 2019, and without known chromosomal abnormalities. At a mean (standard deviation) age of 21.7 (3.7) months, the Bayley Scales of Infant and Toddler Development-III determined motor composite and scaled scores (normative values, 100 (15), 10 (3), respectively). The same variables from surgery and assessment were analysed using multivariate regression to predict gross and fine motor scores; results expressed as effect size (95% confidence interval) with % variance. RESULTS: Composite, fine, and gross motor scores were 89.7 (14.2), 9.4 (2.5), and 7.2 (2.7), respectively. Predictive variables accounted for 21.2% of the variance for fine motor, and 36.9% for gross motor. Multivariate analysis for gross motor scores included toddlers need for cardiac medication, effect size (95% confidence interval) -0.801 (-1.62, -0.02), gastrostomy, -1.35 (-2.39, -0.319), and single ventricle, -0.93 (-1.71, -0.15). These same variables did not predict fine motor scores. CONCLUSION: Gross motor skills commonly were lower than fine motor skills for toddlers after complex cardiac surgery. Predictors for gross motor scores differed from fine motor scores. Separate reporting of gross motor scores could lead to improved identification of predictors of delay and to optimised early intervention.

Neurodevelopmental Outcomes of Infants after Neonatal Surgical Intervention for Tetralogy of Fallot or Pulmonary Atresia.

OBJECTIVE: To determine the 2-year neurodevelopmental outcomes for survivors of neonatal cardiac surgery for the most common right ventricular outflow tract obstructive lesions: tetralogy of Fallot and pulmonary atresia with a ventricular septal defect. STUDY DESIGN: A single-center consecutive cohort of 77 children underwent neonatal surgery for tetralogy of Fallot or pulmonary atresia with a ventricular septal defect at ≤6 weeks of age between 2006 and 2017. The patients underwent a multidisciplinary neurodevelopmental assessment at 18-24 months of age. Survivor outcomes were compared by univariable and multivariable analyses. RESULTS: The 2-year mortality was 7.8% (6/77) with a postoperative in-hospital mortality of 3.9% (3/77). Freedom from reintervention by cardiac catheterization or surgical intervention at 2 years was 36%. Functional and neurodevelopmental assessment for 69 of 71 survivors was completed at a mean age of 22.6 ± 4.0 months using the Bayley Scales of Infant and Toddler Development III. The mean neurodevelopmental outcome scores were 83.4 ± 16.5 for cognitive skills, 82.2 ± 18.7 for language skills, and 81.4 ± 18.1 for motor skills. Cognitive, language, and motor delay, defined as a score of <70, was identified in 25%, 25%, and 23% of patients, respectively. Multivariable analyses for factors associated with worse neurodevelopmental outcomes identified chromosomal anomalies (P < .001) and postoperative complications (P < .03). CONCLUSIONS: Cyanotic tetralogy of Fallot and pulmonary atresia with ventricular septal defect requiring neonatal repair showed similar 2-year neurodevelopmental outcomes below normative values and a high prevalence of cognitive, language and motor delays.

Third Trimester Umbilical Arterial Pulsatility Index is Associated with Neurodevelopmental Outcomes at 2-Years in Major Congenital Heart Disease.

Major congenital heart disease (CHD) is associated with impaired neurodevelopment (ND), partly from prenatal insults. In this study we explore associations between 2nd and 3rd trimester umbilical (UA) and middle cerebral artery (MCA) pulsatility index (PI = systolic-diastolic velocities/mean velocity) in fetuses with major CHD and 2-year ND and growth outcomes. Eligible patients included those with a prenatal diagnosis of CHD from 2007 to 2017 without a genetic syndrome who underwent previously defined cardiac surgeries and 2-year biometric and ND assessments in our program. UA and MCA-PI Z-scores at fetal echocardiography were examined for relationships with 2-year Bayley Scales of Infant and Toddler Development and biometric Z-scores. Data from 147 children was analyzed. Second and 3rd trimester fetal echocardiograms were performed at 22.4 ± 3.7 and 34.7 ± 2.9 weeks (mean ± SD), respectively. Multivariable regression analysis showed an inverse relationship between 3rd trimester UA-PI for all CHD and cognitive - 1.98 (- 3.37, - 0.59), motor - 2.57 (- 4.15, - 0.99), and language - 1.67 (- 3.3, - 0.03) (effect size and 95th confidence interval) ND domains (p < 0.05), with the strongest relationships in the single ventricle and hypoplastic left heart syndrome subgroups. No association was found for 2nd trimester UA-PI or any trimester MCA-PI and ND or between UA or MCA-PI and 2-year growth parameters. Increased 3rd trimester UA-PI, reflecting an altered late gestation fetoplacental circulation, relates to worse 2-year ND in all domains.

A complicated Glenn procedure: risk factors and association with adverse long-term neurodevelopmental and functional outcomes.

OBJECTIVES: To determine potentially modifiable risk factors for a complicated Glenn procedure (cGP) and whether a cGP predicted adverse neurodevelopmental and functional outcomes. A cGP was defined as post-operative death, heart transplant, extracorporeal life support, Glenn takedown, or prolonged ventilation. METHODS: All 169 patients having a Glenn procedure from 2012 to 2017 were included. Neurodevelopmental assessments were performed at age 2 years in consenting survivors (n = 156/159 survivors). The Bayley Scales of Infant and Toddler Development-3rd Edition (Bayley-III) and the Adaptive Behavior Assessment System-2nd Edition (ABAS-II) were administered. Adaptive functional outcomes were determined by the General Adaptive Composite (GAC) score from the ABAS-II. Predictors of outcomes were determined using univariate and multiple variable linear or Cox regressions. RESULTS: Of patients who had a Glenn procedure, 10/169 (6%) died by 2 years of age and 27/169 (16%) had a cGP. Variables statistically significantly associated with a cGP were the inotrope score on post-operative day 1 (HR 1.04, 95%CI 1.01, 1.06; p = 0.010) and use of inhaled nitric oxide post-operatively (HR 7.31, 95%CI 3.19, 16.76; p < 0.001). A cGP was independently statistically significantly associated with adverse Bayley-III Cognitive (ES -10.60, 95%CI -17.09, -4.11; p = 0.002) and Language (ES -11.43, 95%CI -19.25, -3.60; p = 0.004) scores and adverse GAC score (ES -14.89, 95%CI -22.86, -6.92; p < 0.001). CONCLUSIONS: Higher inotrope score and inhaled nitric oxide used post-operatively were associated with a cGP. A cGP was independently associated with adverse 2-year neurodevelopmental and functional outcomes. Whether early recognition and intervention for risk of a cGP can prevent adverse outcomes warrants study.

Kindergarten-age neurocognitive, functional, and quality-of-life outcomes after liver transplantation at under 6 years of age.

BACKGROUND: We aimed to describe school-entry age neurocognitive, functional, and HRQL outcomes and their predictors after liver transplant done at age <6 years. METHODS: A prospective cohort of all (n = 69) children surviving liver transplant from 1999 to 2014 were assessed at age 55.4 (SD 7.2) months and 38.6 (12.4) months after transplant. Assessment included: the Wechsler Preschool and Primary Scales of Intelligence, Beery-Buktenica Developmental Test of VMI, Adaptive Behavior Assessment System caregiver-completed questionnaire, and PedsQL 4.0 Generic Core Scales. Univariate and multiple linear regression determined predictors of outcomes at P < .05. RESULTS: Neurocognitive and functional outcomes were on average within 1 SD of population norms, although shifted to the left (P ≤ .03), with more patients than expected having scores >2 (3.7-5.9 times more, P ≤ .007) SD below population norms. Total and Summary HRQL scores were statistically significantly lower than the healthy normative population (P ≤ .02) and a congenital heart disease group (P ≤ .02), but similar to children with other chronic health conditions; differences often exceeded the MCID and were lowest in the School functioning domain. There were few predictors on multiple linear regressions, and we could not confirm previous studies that suggested various inconsistent predictors of outcomes. Neurocognitive and functional outcomes scores were highly correlated with HRQL scores except for the School functioning domain, but did not fully explain them. CONCLUSIONS: Long-term follow-up of this vulnerable population is important in order to facilitate support for the patient and family, and early intervention for any difficulties identified.

Health-related quality of life after pediatric heart transplantation in early childhood.

BACKGROUND: There is limited information about HRQL after pediatric heart transplantation at a young age. METHODS: Prospective follow-up study of children who received a heart transplant at age ≤4 years. HRQL was assessed using the PedsQLTM 4.0 at age 4.5 years. This cohort was compared with healthy children, children with CHD, and with chronic conditions. Peri-operative factors associated with HRQL were also explored. RESULTS: Of 66 eligible patients, 15 (23%) died prior to the HRQL assessment and 2 (3%) were lost to follow-up, leaving 49 patients. Indication for transplantation was CHD in 27 (55%) and CMP in 22 (45%). Median age (IQR) at transplant was 9 (5-31) months. HRQL was significantly lower in transplanted children compared to population norms (65.3 vs 87.3, P < .0001), children with chronic conditions (65.3 vs 76.1, P = .001), and children with CHD (65.3 vs 81.1, P < .0001). Transplanted children with CHD had lower HRQL than those with a prior diagnosis of CMP (59.5 vs 72.5, P-value = .020). Higher creatinine pretransplant and higher lactate post-operatively were associated with lower HRQL. CONCLUSION: Children after heart transplant had significantly lower HRQL, as reported by their parents, than the normative population, children with chronic conditions, and children with CHD.

Longitudinal linear combination test for gene set analysis.

BACKGROUND: Although microarray studies have greatly contributed to recent genetic advances, lack of replication has been a continuing concern in this area. Complex study designs have the potential to address this concern, though they remain undervalued by investigators due to the lack of proper analysis methods. The primary challenge in the analysis of complex microarray study data is handling the correlation structure within data while also dealing with the combination of large number of genetic measurements and small number of subjects that are ubiquitous even in standard microarray studies. Motivated by the lack of available methods for analysis of repeatedly measured phenotypic or transcriptomic data, herein we develop a longitudinal linear combination test (LLCT). RESULTS: LLCT is a two-step method to analyze multiple longitudinal phenotypes when there is high dimensionality in response and/or explanatory variables. Alternating between calculating within-subjects and between-subjects variations in two steps, LLCT examines if the maximum possible correlation between a linear combination of the time trends and a linear combination of the predictors given by the gene expressions is statistically significant. A generalization of this method can handle family-based study designs when the subjects are not independent. This method is also applicable to time-course microarray, with the ability to identify gene sets that exhibit significantly different expression patterns over time. Based on the results from a simulation study, LLCT outperformed its alternative: pathway analysis via regression. LLCT was shown to be very powerful in the analysis of large gene sets even when the sample size is small. CONCLUSIONS: This self-contained pathway analysis method is applicable to a wide range of longitudinal genomics, proteomics, metabolomics (OMICS) data, allows adjusting for potentially time-dependent covariates and works well with unbalanced and incomplete data. An important potential application of this method could be time-course linkage of OMICS, an attractive possibility for future genetic researchers. AVAILABILITY: R package of LLCT is available at: https://github.com/its-likeli-jeff/LLCT.

Avoiding Furosemide Ototoxicity Associated With Single-Ventricle Repair in Young Infants.

OBJECTIVE: To reduce bilateral delayed-onset progressive sensory permanent hearing loss using a systems-wide quality improvement project with adherence to best practice for the administration of furosemide. DESIGN: Prospective cohort study with regular audiologic follow-up assessment of survivors both before and after a 2007-2008 quality improvement practice change. SETTING: The referral center in Western Canada for complex cardiac surgery, with comprehensive multidisciplinary follow-up by the Complex Pediatric Therapies Follow-up Program. PATIENTS: All consecutive patients having single-ventricle palliative cardiac surgery at age 6 weeks old or younger. INTERVENTIONS: A 2007-2008 quality improvement practice change consisted of a Parenteral Drug Monograph revision indicating slow IV administration of furosemide, an educational program, and an evaluation. MEASUREMENTS AND MAIN RESULTS: The outcome measure was the prevalence of permanent hearing loss by 4 years old. Firth multiple logistic regression compared pre (1996-2008) to post (2008-2012) practice change occurrence of permanent hearing loss, adjusting for confounding variables, including all hospital days, extracorporeal membrane oxygenation, cardiopulmonary bypass time, age at first surgery, dialysis, and sepsis. From 1996 to 2012, 259 infants had single-ventricle palliative surgery at age 6 weeks old or younger, with 173 (64%) surviving to age 4 years. Of survivors, 106 (61%) were male, age at surgery was 11.6 days (9.0 d), and total hospitalization days by age 4 years were 64 (42); 18 (10%) had cardiopulmonary resuscitation and 38 (22%) had sepsis at any time. All 173 (100%) had 4-year follow-up. Pre- to postpractice change permanent hearing loss dropped from 17/100 (17%) to 0/73 (0%) of survivors. On Firth multiple logistic regression, the only variable statistically associated with permanent hearing loss was the pre- to postpractice change time period (odds ratio, 0.03; 95% CI, 0-0.35; p = 0.001). CONCLUSIONS: A practice change to ensure slow IV administration of furosemide eliminated permanent hearing loss. Centers caring for critically ill infants, particularly those with single-ventricle anatomy or hypoxia, should review their drug administration guidelines and adhere to best practice for administration of IV furosemide.

Deterioration of functional abilities in children surviving the Fontan operation.

Functional abilities are needed for activities of daily living. In general, these skills expand with age. We hypothesised that, in contrast to what is normally expected, children surviving the Fontan may have deterioration of functional abilities, and that peri-Fontan stroke is associated with this deterioration. All children registered in the Western Canadian Complex Pediatric Therapies Follow-up Program who survived a Fontan operation in the period 1999-2016 were eligible for inclusion. At the age of 2 years (pre-Fontan) and 4.5 years (post-Fontan), the Adaptive Behavior Assessment System-II general adaptive composite score was determined (population mean: 100, standard deviation: 15). Deterioration of functional abilities was defined as ⩾1 standard deviation decrease in pre- to post-Fontan scores. Perioperative strokes were identified through chart review. Multivariable logistic regression analysis determined predictors of deterioration of functional abilities. Of 133 children, with a mean age at Fontan of 3.3 years (standard deviation 0.8) and 65% male, the mean (standard deviation) general adaptive composite score was 90.6 (17.5) at 2 years and 88.3 (19.1) at 4.5 years. After Fontan, deterioration of functional abilities occurred in 34 (26%) children, with a mean decline of 21.8 (7.1) points. Evidence of peri-Fontan stroke was found in 10 (29%) children who had deterioration of functional abilities. Peri-Fontan stroke (odds ratio 5.00 (95% CI 1.74, 14.36)) and older age at Fontan (odds ratio 1.67 (95% CI 1.02, 2.73)) predicted functional deterioration. The trajectory of functional abilities should be assessed in this population, as more than 25% experience deterioration. Efforts to prevent peri-Fontan stroke, and to complete the Fontan operation at an earlier age, may lead to reduction of this deterioration.

Bisphenol A Metabolites and Bisphenol S in Paired Maternal and Cord Serum.

Human studies show associations between maternal bisphenol A (BPA) exposure and developmental effects in children, yet biomonitoring of BPA metabolites in maternal and fetal serum remains limited, and less is known for BPA alternatives. BPA-glucuronide, BPA-sulfate, and bisphenol S (BPS) were quantified in 61 pairs of maternal and cord sera from Chinese participants. Total BPS was only detectable in four maternal (<0.03-0.07 ng/mL) and seven cord sera (<0.03-0.12 ng/mL), indicating low exposure but providing the first evidence that BPS crosses the human placenta. Total BPA metabolites in cord serum were significantly higher than in maternal serum (p < 0.05), suggesting that these may be formed in the fetus or cleared more slowly from the fetoplacental compartment. Unlike the pharmacokinetic results from controlled oral exposure studies in which BPA-glucuronide is the major BPA metabolite, here, BPA-sulfate was the dominant metabolite (GM: 0.06 and 0.08 ng/mL), significantly higher than BPA-glucuronide (GM: 0.02 and 0.04 ng/mL) (p < 0.01) in both maternal and cord sera. Moreover, the proportion of BPA-sulfate increased with total BPA. These are the first human data for BPA metabolites in paired maternal and cord serum, and results suggest that the human fetus and pregnant mother have unique exposure to BPA metabolites. Direct analysis of BPA metabolites in serum provides complementary information for evaluating early life-stage exposure and risks of BPA.

Pilot randomized controlled trial on early and late remote ischemic preconditioning prior to complex cardiac surgery in young infants.

BACKGROUND: Remote ischemic preconditioning involves providing a brief ischemia-reperfusion event to a tissue to create subsequent protection from a more severe ischemia-reperfusion event to a different tissue/organ. The few pediatric remote ischemic preconditioning studies in the literature show conflicting results. AIM: We conducted a pilot randomized controlled trial to determine the feasibility of conducting a larger trial and to gather provisional data on the effect of early and late remote ischemic preconditioning on outcomes of infants after surgery for congenital heart disease. METHODS: This single-center, double-blind randomized controlled trial of remote ischemic preconditioning vs control (sham-remote ischemic preconditioning) in young infants going for surgery for congenital heart disease at the Stollery Children's Hospital. Remote ischemic preconditioning was performed at 24-48 h preoperatively and immediately prior to cardiopulmonary bypass. Remote ischemic preconditioning stimulus was performed with blood pressure cuffs around the thighs. Primary outcomes were feasibility and peak blood lactate level on day 1 postoperatively. RESULTS: Fifty-two patients were randomized but seven patients became ineligible after randomization leaving 45 patients included in the study. In the included patients, 7 (15%) had protocol deviations (five infants did not have the preoperative intervention and two did not receive the intervention in the operating room). From a comfort point of view, only one subject in the control group and two in the Remote ischemic preconditioning group received sedation during the preoperative intervention. There were no study-related adverse events and no complications to the limbs subjected to preconditioning. There were no significant differences between the Remote ischemic preconditioning group and the control group in the highest blood lactate level on day 1 postoperatively (mean difference, 1.28; 95%CI, -0.22, 2.78; P-value = 0.093). CONCLUSION: In infants who underwent surgery for congenital heart disease, our pilot randomized controlled trial on early and late remote ischemic preconditioning proved to be feasible but did not find any significant difference in acute outcomes. A larger trial may be necessary.

Screening for language delay after life-saving therapies in term-born infants.

BACKGROUND: Strong recommendations have been made for the periodic developmental surveillance, screening, and evaluation of children with CHD. This supports similar calls for all at-risk children in order to provide timely, structured early developmental intervention that may improve outcomes. The aim of this study was to determine the accuracy of screening for language delay after life-saving therapies using the parent-completed vocabulary screen of the language Development Survey, by comparing screening with the individually administered language scores of the Bayley Scales of Infant and Toddler Development, Third edition. METHOD: In total, 310 (92.5%) of 335 eligible term-born children, born between 2004 and 2011, receiving complex cardiac surgery, heart or liver transplantation, or extracorporeal membrane oxygenation in infancy, were assessed at 21.5 (2.8) months of age (lost, 25 (7.5%)), through developmental/rehabilitation centres at six sites as part of the Western Canadian Complex Pediatric Therapies Follow-up Group. RESULTS: Vocabulary screening delay was defined as scores ⩽15th percentile. Language delay defined as scores >1 SD below the mean was calculated for language composite score, receptive and expressive communication scores of the Bayley-III. Delayed scores for the 310 children were as follows: vocabulary, 144 (46.5%); language composite, 125 (40.3%); receptive communication, 98 (31.6%); and expressive communication, 124 (40%). Sensitivity, specificity, positive predictive values, and negative predictive values of screened vocabulary delay for tested language composite delay were 79.2, 75.7, 68.8, and 84.3%, respectively. CONCLUSION: High rates of language delay after life-saving therapies are concerning. Although the screening test appears to over-identify language delay relative to the tested Bayley-III, it may be a useful screening tool for early language development leading to earlier referral for intervention.

Neurocognitive outcomes at kindergarten entry after surgical repair of total anomalous pulmonary venous connection in early infancy.

The objective of this study was to determine neurocognitive outcomes 4.5 years after surgery for TAPVC in infancy and predictors of these outcomes. A cohort having TAPVC repair at age ≤6 weeks between 1998 and 2007 were followed by the Complex Pediatric Therapies Follow-up Program at 4.5 years. Outcomes include mortality, full-scale intelligence quotient (FSIQ), verbal IQ (VIQ), performance IQ (PIQ), visual motor integration (VMI), and general adaptive composite of the Adaptive Behavior Assessment System (GAC). There were 51 infants with simple TAPVC [4 year mortality 4 (8%)], and 16 with complex TAPVC [4 year mortality 7 (44%)], hazard ratio (HR) 7.02 (95% CI 2.05-24.07, p = 0.002). Of the 47 survivors after simple TAPVC, FSIQ (SD) was 92 (17), VIQ 92 (17), PIQ 94 (15), VMI 92 (15), and GAC 92 (15). Independent predictors of neurocognitive outcome included father's socioeconomic status, mother's years of schooling, gender, post-operative base deficit, and deep hypothermic circulatory arrest (DHCA) time. Complex TAPVC was associated on univariate analysis only with PIQ [81.9 (10.2) vs. 93.6 (15.4); p = 0.012] and FSIQ [80.7 (10.1) vs. 92.0 (17.7); p = 0.017]. Original peoples accounted for 25/51 (49%) of simple and 3/16 (19%) of complex TAPVC. Original peoples race was associated with 4-year mortality [HR 6.85 (95% CI 2.15, 21.76, p = 0.001)]. Survivors of TAPVC repair in early infancy have encouraging neurocognitive outcomes. Few independent predictors of neurocognitive outcome were found, with post-operative acidosis and DHCA time being potentially modifiable. Original peoples account for an unexpected proportion of patients (42%) and have a higher mortality.

Prediction of preschool functional abilities after early complex cardiac surgery.

BACKGROUND: It is important to identify early predictors of functional limitations in children after congenital heart surgery to optimise their independence as they prepare for school. The purpose of this study is to determine potentially modifiable predictor variables of functional abilities in pre-school children who underwent complex cardiac surgery at 6 weeks of age or earlier. METHODS: This prospective inception cohort study comprised a sample of 165 survivors (63% boys) who had complex cardiac surgery (75% biventricular repairs) at Stollery Children's Hospital, Edmonton, Alberta. We excluded children with chromosomal abnormalities. When children were 4-5 years of age, the parents completed the Adaptive Behavioral Assessment System II. Regression analysis was used to assess the association between multiple risk factors and each of the four continuous composite scores. RESULTS: The mean scores for the practical domain and general adaptive composite score of the Adaptive Behavioural Assessment System were lower than the conceptual and social domains, with 13.3% of the children having a delay in the practical domain. There was a significant association between the general adaptive (p=0.003; 0.012), conceptual (p=0.0004; 0.042), social (p=0.0007; 0.028), and the practical (p=0.046; 0.003) domain composite scores with the mother's education and preoperative plasma lactate, respectively. CONCLUSION: Maternal education may be a marker for the social context of children, and warrants societal attention to improve functional outcomes. Preoperative lactate as a potentially modifiable variable may warrant increased attention to early diagnosis and aggressive resuscitation of young infants with congenital heart disease.

Gene set enrichment analysis for multiple continuous phenotypes.

BACKGROUND: Gene set analysis (GSA) methods test the association of sets of genes with phenotypes in gene expression microarray studies. While GSA methods on a single binary or categorical phenotype abounds, little attention has been paid to the case of a continuous phenotype, and there is no method to accommodate correlated multiple continuous phenotypes. RESULT: We propose here an extension of the linear combination test (LCT) to its new version for multiple continuous phenotypes, incorporating correlations among gene expressions of functionally related gene sets, as well as correlations among multiple phenotypes. Further, we extend our new method to its nonlinear version, referred as nonlinear combination test (NLCT), to test potential nonlinear association of gene sets with multiple phenotypes. Simulation study and a real microarray example demonstrate the practical aspects of the proposed methods. CONCLUSION: The proposed approaches are effective in controlling type I errors and powerful in testing associations between gene-sets and multiple continuous phenotypes. They are both computationally effective. Naively (univariately) analyzing a group of multiple correlated phenotypes could be dangerous. R-codes to perform LCT and NLCT for multiple continuous phenotypes are available at http://www.ualberta.ca/~yyasui/homepage.html.

Health-related quality of life in pediatric cardiac extracorporeal life support survivors.

OBJECTIVE: To assess the health-related quality of life of children who received cardiac extracorporeal life support. We hypothesized that extracorporeal life support survivors have lower health-related quality-of-life scores when compared with a healthy sample, with children with chronic conditions, and with children who had surgery for congenital heart disease and did not receive extracorporeal life support. DESIGN: Prospective cohort study. SETTING: Stollery Children's Hospital and Complex Pediatric Therapies Follow-up Program clinics. PATIENTS: Children less than or 5 years old with diagnosis of cardiac disease (congenital or acquired) who received extracorporeal life support at the Stollery Children's Hospital from 1999 to 2009. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Health-related quality of life was assessed using the PedsQL 4.0 Generic Core Scales completed by the children's parents at the time of follow-up. Forty-seven cardiac extracorporeal life support survivors had their health-related quality of life assessed at a median age of 4 years. Compared with a healthy sample, children who received venoarterial extracorporeal life support have significantly lower PedsQL (64.9 vs 82.2; p < 0.0001). The PedsQL scores of children who received extracorporeal life support were also significantly lower than those of children with chronic health conditions (64.9 vs 73.1; p = 0.007). Compared with children with congenital heart disease who underwent cardiac surgery early in infancy and who did not receive extracorporeal life support, extracorporeal life support survivors had significantly lower PedsQL scores (64.9 vs 81.1; p < 0.0001). Multiple linear regression analysis found an independent association between both higher inotrope score in the first 24 hours of extracorporeal life support and longer hospital length of stay, with lower PedsQL scores. CONCLUSIONS: Pediatric cardiac extracorporeal life support survivors showed lower health-related quality of life than healthy children, children with chronic conditions, and children with congenital heart disease who did not receive extracorporeal life support.

Neurotoxicity of sedative and analgesia drugs in young infants with congenital heart disease: 4-year follow-up.

OBJECTIVES/AIM: To determine whether sedation/analgesia drugs used before, during, and after infant cardiac surgery are associated with neurocognitive and functional outcomes. BACKGROUND: Some animal models suggest neurotoxic effects of anesthetic drugs on the developing brain; however, potential human effects are unknown. Whether these results can be extrapolated to humans is unknown. METHODS/MATERIALS: Prospective follow-up project of all infants ≤6 weeks old having surgery for congenital heart disease between 04/03 and 12/06. Demographic, perioperative, and sedation/analgesia variables were collected. Outcomes at kindergarten age were Wechsler Preschool and Primary Scale of Intelligence-III, Beery-Buktenica Developmental Test of Visual Motor Integration (VMI-V), and General Adaptive Composite (GAC) of the Adaptive Behavior Assessment System-II. Multivariable linear regression was used to identify predictor variables. RESULTS: From 135 infants who underwent heart surgery, 19 died, 17 were excluded, 8 were lost to follow-up, leaving 91 children for analysis. Multiple linear regression found days on chloral hydrate [3.5 (3.7) days] was associated with lower performance intelligence quotient (PIQ) (Effect size -1.03; 95% CI -1.96, -0.10; P = 0.03), and cumulative dose [54.2 (60.3) mg·kg(-1) ] of benzodiazepines was associated with lower VMI scores (Effect size -0.07; 95% CI -0.12, -0.01; P = 0.026). No other associations were found between sedation/analgesia variables and full-scale IQ, PIQ, Verbal IQ, VMI, or GAC. CONCLUSION: Assessment of this cohort at kindergarten age found a small statistically significant association between days on chloral hydrate and PIQ, and benzodiazepine cumulative dose and lower VMI. No other association between sedation/analgesia drugs and outcomes was found.

Health-related quality of life experienced by children with chromosomal abnormalities and congenital heart defects.

Long-term outcomes are fundamental in advising parents about the potential future of their children with congenital heart disease (CHD). No published reports have described the health-related quality of life (HRQL) experienced by children with chromosomal abnormalities who had surgery in early infancy for CHD. A study was undertaken to assess HRQL among children with chromosomal abnormalities and CHD. The authors hypothesized that these children have a worse HRQL than healthy children or a cohort of children matched for CHD diagnosis. Infants with chromosomal abnormalities undergoing cardiac surgery for CHD at 6 weeks of age or younger at the Stollery Children's Hospital between July 2000 and June 2005 were included in the study. The HRQL of these infants was assessed using the Pediatric Quality of Life Inventory (PedsQL) 4.0 Generic Core Scales completed by their parents at a 4-year follow-up evaluation. The study compared the scores for 16 children with normative data. The children with chromosomal abnormalities and CHD had significantly lower mean total PedsQL (71.3 vs. 87.3; p < 0.0001), Psychosocial Summary (70.3 vs. 86.1; p < 0.0001), and Physical Summary (74.3 vs. 89.2; p = 0.0006) scores. Compared with the matched children, those with chromosomal abnormalities had a significantly lower median total PedsQL (75.0 vs. 84.6; p = 0.03), Physical Summary (79.5 vs. 96.9; p = 0.007), and School Functioning (68.5 vs. 83.0; p = 0.03) scores. A better understanding of the mechanisms and determinants of HRQL in these children has the potential to yield important implications for clinical practice including clarity for treatment decision making as well as determination of targeted supports and services to meet the needs of these children and their families differentially.

Linear combination test for gene set analysis of a continuous phenotype.

BACKGROUND: Gene set analysis (GSA) methods test the association of sets of genes with a phenotype in gene expression microarray studies. Many GSA methods have been proposed, especially methods for use with a binary phenotype. Equally, if not more importantly however, is the ability to test the enrichment of a gene signature or pathway against the continuous phenotypes which are routinely and commonly observed in, for example, clinicopathological measurements. It is not always easy or meaningful to dichotomize continuous phenotypes into two classes, and attempting to do this may lead to the inaccurate classification of samples, which would affect the downstream enrichment analysis. In the present study, we have build on recent efforts to incorporate correlation structure within gene sets and pathways into the GSA test statistic. To address the issue of continuous phenotypes directly without the need for artificial discrete classification and thus increase the power of the test while ensuring computational efficiency and rigor, new GSA methods that can incorporate a covariance matrix estimator for a continuous phenotype may present an effective approach. RESULTS: We have designed a new method by extending the GSA approach called Linear Combination Test (LCT) from a binary to a continuous phenotype. Simulation studies and a real microarray dataset were used to compare the proposed LCT for a continuous phenotype, a modification of LCT (referred to as LCT2), and two publicly available GSA methods for continuous phenotypes. CONCLUSIONS: We found that the LCT methods performed better than the other two GSA methods; however, this finding should be understood in the context of our specific simulation studies and the real microarray dataset that were used to compare the methods. Free R-codes to perform LCT for binary and continuous phenotypes are available at http://www.ualberta.ca/~yyasui/homepage.html. The R-code to perform LCT for a continuous phenotype is available as Additional file 1.