uConsent: Addressing the gap in measuring understanding of informed consent in clinical research.

The purpose of this study was to establish the technical merit, feasibility, and generalizability of a new measure of understanding of informed consent for use with clinical research participants. A total of 109 teens/young adults at a large, pediatric medical center completed the consenting process of a hypothetical biobanking study. Data were analyzed using a combination of classical and modern theory analytic methods to produce a final set of 19 items referred to as the uConsent scale. A requirement of the scale was that each item mapped directly onto one or more of the Basic Elements of Informed Consent from the 2018 Final Rule. Descriptive statistics were computed for each item as well as the scale as a whole. Partial credit (Rasch) logistic modeling was then used to generate difficulty/endorsability estimates for each item. The final, 19-item uConsent scale was derived using inferential methods to yield a set of items that ranged across difficulty levels (-3.02 to 3.10 logits) with a range of point-measure correlations (0.12 to 0.50), within-range item- and model-fit statistics, varying item types mapped to both Bloom's Taxonomy of Learning and required regulatory components of the 2018 Final Rule. Median coverage rate for the uConsent scale was 95% for the 25 randomly selected studies from ClinicalTrials.gov. The uConsent scale may be used as an effective measure of informed consent when measuring and documenting participant understanding in clinical research studies today.

Anesthesia and Sedation Exposure and Neurodevelopmental Outcomes in Infants Undergoing Congenital Cardiac Surgery: A Retrospective Cohort Study.

BACKGROUND: Children undergoing complex cardiac surgery are exposed to substantial cumulative doses of sedative medications and volatile anesthetics and are more frequently anesthetized with ketamine, compared with healthy children. This study hypothesized that greater exposure to sedation and anesthesia in this population is associated with lower neurodevelopmental scores at 18 months of age. METHODS: A secondary analysis was conducted of infants with congenital heart disease who participated in a prospective observational study of environmental exposures and neurodevelopmental outcomes to assess the impact of cumulative volatile anesthetic agents and sedative medications. Cumulative minimum alveolar concentration hours of exposure to volatile anesthetic agents and all operating room and intensive care unit exposures to sedative and anesthesia medications were collected before administration of Bayley Scales of Infant and Toddler Development, 3rd edition (Bayley III), at 18 months of age. RESULTS: The study cohort included 41 (37%) single-ventricle and 69 (63%) two-ventricle patients. Exposures to volatile anesthetic agents, opioids, benzodiazepines, and dexmedetomidine were not associated with abnormal Bayley III scores. At 18-month follow-up, after adjusting for confounders, each mg/kg increase in ketamine exposure was associated with a 0.34 (95% CI, -0.64 to -0.05) point decrease in Bayley III motor scores (P = 0.024). CONCLUSIONS: Total cumulative exposures to volatile anesthetic agents were not associated with neurodevelopmental impairment in infants with congenital heart disease undergoing various imaging studies and procedures, whereas higher ketamine doses were associated with poorer motor performance.

Towards artefact-free AFM image presentation and interpretation.

Atomic force microscopy (AFM) is based upon a simple operational principle. However, the presentation and interpretation of AFM images can easily suffer from consequential artefacts that are easily overlooked. Here we discuss results from AFM and its companion variations AFM-IR (AFM combined with infrared spectroscopy) and PF-QNM (an AFM mode called peak-force quantitative nano-mechanical mapping) by imaging 'bee' structures in asphalt binder (bitumen) as examples. We show how common problems manifest themselves and provide solutions, with the intent that authors can present their results clearly and avoid interpreting artefacts as true physical properties, thereby raising the quality of AFM research.

Childhood exposures to environmental chemicals and neurodevelopmental outcomes in congenital heart disease.

BACKGROUND: Children with congenital heart defects have an increased risk of neurodevelopmental disability. The impact of environmental chemical exposures during daily life on neurodevelopmental outcomes in toddlers with congenital heart defects is unknown. METHODS: This prospective study investigated the impacts of early childhood exposure to mixtures of environmental chemicals on neurodevelopmental outcomes after cardiac surgery. Outcomes were assessed at 18 months of age using The Bayley Scales of Infant and Toddler Development-III. Urinary concentrations of exposure biomarkers of pesticides, phenols, parabens, and phthalates, and blood levels of lead, mercury, and nicotine were measured at the same time point. Bayesian profile regression and weighted quantile sum regression were utilized to assess associations between mixtures of biomarkers and neurodevelopmental scores. RESULTS: One-hundred and forty infants were enrolled, and 110 (79%) returned at 18 months of age. Six biomarker exposure clusters were identified from the Bayesian profile regression analysis; and the pattern was driven by 15 of the 30 biomarkers, most notably 13 phthalate biomarkers. Children in the highest exposure cluster had significantly lower adjusted language scores by -9.41 points (95%CI: -17.2, -1.7) and adjusted motor scores by -4.9 points (-9.5, -0.4) compared to the lowest exposure. Weighted quantile sum regression modeling for the overall exposure-response relationship showed a significantly lower adjusted motor score (ß = -2.8 points [2.5th and 97.5th percentile: -6.0, -0.6]). The weighted quantile sum regression index weights for several phthalates, one paraben, and one phenol suggest their relevance for poorer neurodevelopmental outcomes. CONCLUSIONS: Like other children, infants with congenital heart defects are exposed to complex mixtures of environmental chemicals in daily life. Higher exposure biomarker concentrations were associated with significantly worse performance for language and motor skills in this population.

Pulmonary atresia with intact ventricular septum: Intended strategies.

OBJECTIVE: Neonatal interventional strategies for pulmonary atresia with intact ventricular septum are based on tricuspid valve hypoplasia and right ventricle-dependent coronary circulation. We sought to evaluate long-term outcomes comparing biventricular (BiV) versus single-ventricle (SV) strategies. METHODS: Retrospective review was performed of 119 patients diagnosed with pulmonary atresia with intact ventricular septum from 1995 to 2018. Descriptive statistics summarized patient characteristics and a multivariable Cox survival model was used to compare treatment strategies. RESULTS: Of 119 patients, 62 (52.1%) were male and 13 (10.9%) had a chromosomal abnormality. BiV was pursued in 53.8% (64 out of 119) and SV in 46.2% (55 out of 119) with median tricuspid valve z scores of -1.59 (interquartile range, -3.03 to 0.21) and -5.12 (interquartile range, -5.60 to -4.06), respectively. The median follow-up was 6 years (interquartile range, 2-15 years). Overall survival at 1, 3, and 10 years was 82.4% (98 out of 119), 80.6% (96 out of 119) and 79.8% (95 out of 119), respectively. End states include 36 (30.3%) BiV, 33 (27.7%) SV, 22 (18.5%) alive without definitive end state, 21 (17.6%) death before end state, 4 (3.4%) 1-and-a-half ventricle, and 3 (2.5%) transplants. No SV were converted to BiV, whereas 4 out of 64 (6.3%) BiV were converted to SV. After adjusting for gender, chromosomal abnormalities, gestational age, and birth weight, SV patients had a significantly higher hazard of mortality (hazard ratio, 9.0; 95% CI, 2.65-30.69; P < .001). Mortality was higher in those with right ventricle-dependent coronary circulation (41.9% [13 out of 31]) compared with those without right ventricle-dependent coronary circulation (7.3% [6 out of 82]) (P < .001). CONCLUSIONS: Pulmonary atresia with intact ventricular septum remains a challenging lesion for those patients on the SV pathway, particularly with right ventricle-dependent coronary circulation.

Effect of parental origin of damaging variants in pro-angiogenic genes on fetal growth in patients with congenital heart defects: Data and analyses.

The placenta is a highly vascular structure composed of both maternal and fetal elements. We have determined that damaging variants in genes responsible for the positive regulation of angiogenesis (PRA) (GO:0045766) that are inherited by the fetus impair fetal growth and placental function in pregnancies involving critical congenital cardiac defects (Russell et al., 2019). In this dataset, we present the specific genetic variants identified, describe the parental origin of each variant where possible and present the analyses regarding the potential effects of parental origin of the variant on placental function and fetal growth. The data presented are related to the research article "Damaging variants in pro-angiogenic genes impair growth in fetuses with cardiac defects" (Russell et al., 2019).

Understanding Calcium-Mediated Adhesion of Nanomaterials in Reservoir Fluids by Insights from Molecular Dynamics Simulations.

Interest in nanomaterials for subsurface applications has grown markedly due to their successful application in a variety of disciplines, such as biotechnology and medicine. Nevertheless, nanotechnology application in the petroleum industry presents greater challenges to implementation because of the harsh conditions (i.e. high temperature, high pressure, and high salinity) that exist in the subsurface that far exceed those present in biological applications. The most common subsurface nanomaterial failures include colloidal instability (aggregation) and sticking to mineral surfaces (irreversible retention). We previously reported an atomic force microscopy (AFM) study on the calcium-mediated adhesion of nanomaterials in reservoir fluids (S. L. Eichmann and N. A. Burnham, Sci. Rep. 7, 11613, 2017), where we discovered that the functionalized and bare AFM tips showed mitigated adhesion forces in calcium ion rich fluids. Herein, molecular dynamics reveal the molecular-level details in the AFM experiments. Special attention was given to the carboxylate-functionalized AFM tips because of their prominent ion-specific effects. The simulation results unambiguously demonstrated that in calcium ion rich fluids, the strong carboxylate-calcium ion complexes prevented direct carboxylate-calcite interactions, thus lowering the AFM adhesion forces. We performed the force measurement simulations on five representative calcite crystallographic surfaces and observed that the adhesion forces were about two to three fold higher in the calcium ion deficient fluids compared to the calcium ion rich fluids for all calcite surfaces. Moreover, in calcium ion deficient fluids, the adhesion forces were significantly stronger on the calcite surfaces with higher calcium ion exposures. This indicated that the interactions between the functionalized AFM tips and the calcite surfaces were mainly through carboxylate interactions with the calcium ions on calcite surfaces. Finally, when analyzing the order parameters of the tethered functional groups, we observed significantly different behavior of the alkanethiols depending on the absence or presence of calcium ions. These observations agreed well with AFM experiments and provided new insights for the competing carboxylate/calcite/calcium ion interactions.

Damaging Variants in Proangiogenic Genes Impair Growth in Fetuses with Cardiac Defects.

OBJECTIVE: To determine the impact of damaging genetic variation in proangiogenic pathways on placental function, complications of pregnancy, fetal growth, and clinical outcomes in pregnancies with fetal congenital heart defect. STUDY DESIGN: Families delivering a baby with a congenital heart defect requiring surgical repair in infancy were recruited. The placenta and neonate were weighed and measured. Hemodynamic variables were recorded from a third trimester (36.4 ± 1.7 weeks) fetal echocardiogram. Exome sequencing was performed on the probands (N = 133) and consented parents (114 parent-child trios, and 15 parent-child duos) and the GeneVetter analysis tool used to identify damaging coding sequence variants in 163 genes associated with the positive regulation of angiogenesis (PRA) (GO:0045766). RESULTS: In total, 117 damaging variants were identified in PRA genes in 133 congenital heart defect probands with 73 subjects having at least 1 variant. Presence of a damaging PRA variant was associated with increased umbilical artery pulsatility index (mean 1.11 with variant vs 1.00 without; P = .01). The presence of a damaging PRA variant was also associated with lower neonatal length and head circumference for age z score at birth (mean -0.44 and -0.47 with variant vs 0.23 and -0.05 without; P = .01 and .04, respectively). During median 3.1 years (IQR 2.0-4.1 years) of follow-up, deaths occurred in 2 of 60 (3.3%) subjects with no PRA variant and in 9 of 73 (12.3%) subjects with 1 or more PRA variants (P = .06). CONCLUSIONS: Damaging variants in proangiogenic genes may impact placental function and are associated with impaired fetal growth in pregnancies involving a fetus with congenital heart defect.

Perioperative Exposure to Suspect Neurotoxicants From Medical Devices in Newborns With Congenital Heart Defects.

BACKGROUND: Industrial chemicals are increasingly recognized as potential developmental neurotoxicants. Di(2-ethylhexyl) phthalate (DEHP), used to impart flexibility and temperature tolerance to polyvinylchloride, and bisphenol A (BPA), used to manufacture polycarbonate, are commonly present in medical devices. The magnitude of exposure in neonates during hospitalization for cardiac operations is unknown. METHODS: We quantified urinary concentrations of DEHP metabolites and BPA preoperatively and postoperatively in neonates undergoing cardiac operations and their mothers. Urinary concentrations of these biomarkers reflect recent exposures (half-lives are approximately 6 to 24 hours). Biomarker concentrations in mothers' and infants' preoperative and postoperative samples were compared. RESULTS: Operations were performed in 18 infants (mean age, 5 ± 4 [SD] days). The maternal sample was obtained on postpartum day 4 ± 4. The preoperative urine sample was obtained on day-of-life 4 ± 2 and the postoperative sample on day-of-life 6 ± 4. Mean maternal concentrations for DEHP metabolites and BPA were at the 50th percentile for females in the United States general population. Infant preoperative concentrations of 1 DEHP metabolite and BPA were significantly higher than maternal concentrations. Postoperative concentrations for all DEHP metabolites were significantly greater than preoperative concentrations. CONCLUSIONS: There is considerable perioperative exposure to DEHP and BPA for neonates undergoing cardiac operations. Infant concentrations for both BPA and DEHP metabolites were significantly higher than maternal concentrations, consistent with the infant's exposure to medical devices. Further study is needed to determine the potential role of these suspect neurotoxicants in the etiology of neurodevelopmental disability after cardiac operations.

Remote Ischemic Preconditioning Does Not Prevent White Matter Injury in Neonates.

BACKGROUND: Remote ischemic preconditioning (RIPC) is a mechanism to protect tissues from injury during ischemia and reperfusion. We investigated the neuroprotective effects of RIPC in neonates undergoing cardiac surgery. METHODS: The outcome was white matter injury (WMI), assessed by the change in volume of WMI from preoperative to postoperative brain magnetic resonance imaging (MRI). Patients were randomized to RIPC or SHAM. RIPC was induced prior to cardiopulmonary bypass by four 5-minute cycles of blood pressure cuff inflation to produce ischemia of the lower extremity. For patients randomized to SHAM, the cuff was positioned, but not inflated. RESULTS: The study included 67 patients, with 33 randomized to RIPC and 34 randomized to SHAM. Preoperative and postoperative MRIs were available in 50 patients, including 26 of the 33 RIPC patients and 24 of the 34 SHAM patients. There were no differences in baseline and operative characteristics for either the overall study group or the group with evaluable MRIs. WMI was identified in 28% of the patients preoperatively and in 62% postoperatively. There was no difference in the prevalence of WMI by treatment group (p > 0.5). RIPC patients had an average change in WMI of 600 mL3, and SHAM subjects had an average WMI change of 107 mL3. There was no significant difference in the mean value of WMI change between patients who received RIPC and those who received SHAM treatments (p = 0.178). CONCLUSIONS: In this randomized, blinded clinical trial, there was no evidence that use of RIPC provides neuroprotection in neonates undergoing repair of congenital heart defects with cardiopulmonary bypass.

Autosomal dominant mannose-binding lectin deficiency is associated with worse neurodevelopmental outcomes after cardiac surgery in infants.

OBJECTIVES: The MBL2 gene is the major genetic determinant of mannose-binding lectin (MBL)-an acute phase reactant. Low MBL levels have been associated with adverse outcomes in preterm infants. The MBL2Gly54Asp missense variant causes autosomal dominant MBL deficiency. We tested the hypothesis that MBL2Gly54Asp is associated with worse neurodevelopmental outcomes after cardiac surgery in neonates. METHODS: This is an analysis of a previously described cohort of patients with nonsyndromic congenital heart disease who underwent cardiac surgery with cardiopulmonary bypass before age 6 months (n = 295). Four-year neurodevelopment was assessed in 3 domains: Full-Scale Intellectual Quotient, the Visual Motor Integration development test, and the Child Behavior Checklist to assess behavior problems. The Child Behavior Checklist measured total behavior problems, pervasive developmental problems, and internalizing/externalizing problems. A multivariable linear regression model, adjusting for confounders, was fit. RESULTS: MBL2Gly54Asp was associated with a significantly increased covariate-adjusted pervasive developmental problem score (ß = 3.98; P = .0025). Sensitivity analyses of the interaction between age at first surgery and MBL genotype suggested effect modification for the patients with MBL2Gly54Asp (Pinteraction = .039), with the poorest neurodevelopment outcomes occurring in children who had surgery earlier in life. CONCLUSIONS: We report the novel finding that carriers of MBL2Gly54Asp causing autosomal dominant MBL deficiency have increased childhood pervasive developmental problems after cardiac surgery, independent of other covariates. Sensitivity analyses suggest that this effect may be larger in children who underwent surgery at earlier ages. These data support the role of nonsyndromic genetic variation in determining postsurgical neurodevelopment-related outcomes in children with congenital heart disease.

A vascular endothelial growth factor A genetic variant is associated with improved ventricular function and transplant-free survival after surgery for non-syndromic CHD.

BACKGROUND: We have previously shown that the minor alleles of vascular endothelial growth factor A (VEGFA) single-nucleotide polymorphism rs833069 and superoxide dismutase 2 (SOD2) single-nucleotide polymorphism rs2758331 are both associated with improved transplant-free survival after surgery for CHD in infants, but the underlying mechanisms are unknown. We hypothesised that one or both of these minor alleles are associated with better systemic ventricular function, resulting in improved survival. METHODS: This study is a follow-up analysis of 422 non-syndromic CHD patients who underwent neonatal cardiac surgery with cardiopulmonary bypass. Echocardiographic reports were reviewed. Systemic ventricular function was subjectively categorised as normal, or as mildly, moderately, or severely depressed. The change in function was calculated as the change from the preoperative study to the last available study. Stepwise linear regression, adjusting for covariates, was performed for the outcome of change in ventricular function. Model comparison was performed using Akaike's information criterion. Only variables that improved the model prediction of change in systemic ventricular function were retained in the final model. RESULTS: Genetic and echocardiographic data were available for 335/422 subjects (79%). Of them, 33 (9.9%) developed worse systemic ventricular function during a mean follow-up period of 13.5 years. After covariate adjustment, the presence of the VEGFA minor allele was associated with preserved ventricular function (p=0.011). CONCLUSIONS: These data support the hypothesis that the mechanism by which the VEGFA single-nucleotide polymorphism rs833069 minor allele improves survival may be the preservation of ventricular function. Further studies are needed to validate this genotype-phenotype association and to determine whether this mechanism is related to increased vascular endothelial growth factor production.

Hearing Loss after Cardiac Surgery in Infancy: An Unintended Consequence of Life-Saving Care.

OBJECTIVES: To investigate the prevalence of hearing loss after cardiac surgery in infancy, patient and operative factors associated with hearing loss, and the relationship of hearing loss to neurodevelopmental outcomes. STUDY DESIGN: Audiologic and neurodevelopmental evaluations were conducted on 348 children who underwent repair of congenital heart disease at the Children's Hospital of Philadelphia as part of a prospective study evaluating neurodevelopmental outcomes at 4 years of age. A prevalence estimate was calculated based on presence and type of hearing loss. Potential risk factors and the impact of hearing loss on neurodevelopmental outcomes were evaluated. RESULTS: The prevalence of hearing loss was 21.6% (95% CI, 17.2-25.9). The prevalence of conductive hearing loss, sensorineural hearing loss, and indeterminate hearing loss were 12.4% (95% CI, 8.8-16.0), 6.9% (95% CI, 4.1-9.7), and 2.3% (95% CI, 0.6-4.0), respectively. Only 18 of 348 subjects (5.2%) had screened positive for hearing loss before this study and 10 used a hearing aid. After adjusting for patient and operative covariates, younger gestational age, longer postoperative duration of stay, and a confirmed genetic anomaly were associated with hearing loss (all P < .01). The presence of hearing loss was associated with worse language, cognition and attention (P <.01). CONCLUSIONS: These findings suggest that the prevalence of hearing loss in preschool children after heart surgery in infancy may be 20-fold higher than in the 1% prevalence seen in the general population. Younger gestational age, presence of a genetic anomaly, and longer postoperative duration of stay were associated with hearing loss. Hearing loss was associated with worse neurodevelopmental outcomes.

Calcium-Mediated Adhesion of Nanomaterials in Reservoir Fluids.

Globally, a small percentage of oil is recovered from reservoirs using primary and secondary recovery mechanisms, and thus a major focus of the oil industry is toward developing new technologies to increase recovery. Many new technologies utilize surfactants, macromolecules, and even nanoparticles, which are difficult to deploy in harsh reservoir conditions and where failures cause material aggregation and sticking to rock surfaces. To combat these issues, typically material properties are adjusted, but recent studies show that adjusting the dispersing fluid chemistry could have significant impact on material survivability. Herein, the effect of injection fluid salinity and composition on nanomaterial fate is explored using atomic force microscopy (AFM). The results show that the calcium content in reservoir fluids affects the interactions of an AFM tip with a calcite surface, as surrogates for nanomaterials interacting with carbonate reservoir rock. The extreme force sensitivity of AFM provides the ability to elucidate small differences in adhesion at the pico-Newton (pN) level and provides direct information about material survivability. Increasing the calcium content mitigates adhesion at the pN-scale, a possible means to increase nanomaterial survivability in oil reservoirs or to control nanomaterial fate in other aqueous environments.

Rates of autism and potential risk factors in children with congenital heart defects.

OBJECTIVE: Atypical development, behavioral difficulties, and academic underachievement are common morbidities in children with a history of congenital heart defects and impact quality of life. Language and social-cognitive deficits have been described, which are associated with autism spectrum disorders. The current study aimed to assess the rates of autism spectrum disorders in a large sample of children with a history of congenital heart defects and to assess medical, behavioral, and individual factors that may be associated with the risk of autism spectrum disorders. DESIGN: Participants included 195 children with a history of congenital heart defects, who are followed in a large-scale longitudinal study. Measures included behavioral data from 4-year-old neurodevelopmental evaluations and parent-report data from a later annual follow-up. RESULTS: Using established cutoffs on an autism spectrum disorder screener, children with congenital heart defects showed higher rates of "possible" autism spectrum disorders than national rates, (Chi-square Test of Equal Proportions), all Ps < .05. A stepwise variable selection method was used to create a "best prediction model" and multivariable logistic regression was used to identify variables predicting diagnostic status. Factors associated with diagnostic risk included medical (delayed sternal closure, prematurity, positive genetic findings), behavioral (cognitive, language, attention issues), and individual (socioeconomic, cultural/racial) variables. ROC analyses identified a cutoff of 7 to maximize sensitivity/specificity based on parent-reported diagnosis. CONCLUSIONS: Risk of autism spectrum disorder screening status in children with congenital heart defects was higher than expected from population rates. Findings highlight the need for referral to a specialist to assess the presence and severity of social-communication issues and congenital heart defects population-specific screening thresholds for children with concern for autism spectrum disorders.

Increasing cumulative exposure to volatile anesthetic agents is associated with poorer neurodevelopmental outcomes in children with hypoplastic left heart syndrome.

OBJECTIVES: Despite improved survival in children with hypoplastic left heart syndrome (HLHS), significant concern persists regarding their neurodevelopmental (ND) outcomes. Previous studies have identified patient factors, such as prematurity and genetic syndromes, to be associated with worse ND outcomes. However, no consistent relationships have been identified among modifiable management factors, including cardiopulmonary bypass strategies, and ND outcomes after cardiac surgery in infancy. Studies in immature animals, including primates, have demonstrated neurodegeneration and apoptosis in the brain after certain levels and extended durations of anesthetic exposure. Retrospective human studies have also suggested relationships between adverse ND effects and anesthetic exposure. METHODS: Cumulative minimum alveolar concentration hours (MAC-hrs) of exposure to volatile anesthetic agents (VAA) (desflurane, halothane, isoflurane, and sevoflurane) were collected from an anesthetic database and medical record review for 96 patients with HLHS or variants. ND testing was performed between ages 4 and 5 years, including full-scale IQ, verbal IQ, performance IQ, and processing speed. Four generalized linear modes were hypothesized a priori and tested using a Gaussian (normal) distribution with an identity link. RESULTS: Cumulative VAA exposure ranged from 0 to 35.3 MAC-hrs (median 7.5 hours). Using specified covariates identified previously as significant predictors of ND outcomes, statistically significant relationships were identified between total MAC-hrs exposure and worse full-scale IQ and verbal IQ scores (P's < .05) alone and after adjusting for relevant covariates. CONCLUSIONS: Increased cumulative MAC-hrs exposure to VAA is associated with worse ND outcomes in certain domains in children with HLHS and variants.

Seminal Postoperative Complications and Mode of Death After Pediatric Cardiac Surgical Procedures.

BACKGROUND: Understanding the seminal complications leading to death after pediatric cardiac surgical procedures may provide opportunities to reduce mortality. This study analyzed all deaths at two pediatric cardiac surgical programs and developed a method to identify the seminal complications and modes of death. METHODS: Trained nurses abstracted all cases of in-hospital mortality meeting inclusion criteria from each site over 5 years (2008 to 2012). Complication definitions were consistent with those of a multicenter clinical registry. An adjudication committee assigned a seminal complication in each case (the complication initiating the cascade of events leading to death). Seminal complications were grouped into categories to designate "mode of death." The epidemiology of seminal complications and of mode of death was described. RESULTS: In 191 subjects, low cardiac output syndrome (71% of all subjects), cardiac arrest (52%), and arrhythmia (48%) were the most common complications. The committee assigned low cardiac output syndrome (30%), failure to separate from bypass (16%), and cardiac arrest (12%) most frequently as seminal complications. Seminal complications occurred a median 2 hours (interquartile range [IQR], 0 to 35 hours) postoperatively. Patients experienced a median of seven (IQR, 3 to 12) additional complications before death at a median of 15 days (IQR, 4 to 46). Systemic circulatory failure was the most common mode of death (51%), followed by inadequate pulmonary blood flow (13%) and cardiac arrest (12%). CONCLUSIONS: Seminal complications occurred early postoperatively, and systemic circulatory failure was the most common mode of death. Our classification system is likely scalable for subsequent multicenter analysis to understand cause-specific mortality variation across hospitals and to drive quality improvement.

Design and initial results of a programme for routine standardised longitudinal follow-up after congenital heart surgery.

BACKGROUND: With improvements in early survival following congenital heart surgery, it has become increasingly important to understand longer-term outcomes; however, routine collection of these data is challenging and remains very limited. We describe the development and initial results of a collaborative programme incorporating standardised longitudinal follow-up into usual care at the Children's Hospital of Philadelphia (CHOP) and University of Michigan (UM). METHODS: We included children undergoing benchmark operations of the Society of Thoracic Surgeons. Considerations regarding personnel, patient/parent engagement, funding, regulatory issues, and annual data collection are described, and initial follow-up rates are reported. RESULTS: The present analysis included 1737 eligible patients undergoing surgery at CHOP from January 2007 to December 2014 and 887 UM patients from January 2010 to December 2014. Overall, follow-up data, of any type, were obtained from 90.8% of patients at CHOP (median follow-up 4.3 years, 92.2% survival) and 98.3% at UM (median follow-up 2.8 years, 92.7% survival), with similar rates across operations and institutions. Most patients lost to follow-up at CHOP had undergone surgery before 2010. Standardised questionnaires assessing burden of disease/quality of life were completed by 80.2% (CHOP) and 78.4% (UM) via phone follow-up. In subsequent pilot testing of an automated e-mail system, 53.4% of eligible patients completed the follow-up questionnaire through this system. CONCLUSIONS: Standardised follow-up data can be obtained on the majority of children undergoing benchmark operations. Ongoing efforts to support automated electronic systems and integration with registry data may reduce resource needs, facilitate expansion across centres, and support multi-centre efforts to understand and improve long-term outcomes in this population.

Burden of potentially pathologic copy number variants is higher in children with isolated congenital heart disease and significantly impairs covariate-adjusted transplant-free survival.

OBJECTIVES: Copy number variants (CNVs) are duplications or deletions of genomic regions. Large CNVs are potentially pathogenic and are overrepresented in children with congenital heart disease (CHD). We sought to determine the frequency of large CNVs in children with isolated CHD, and to evaluate the relationship of these potentially pathogenic CNVs with transplant-free survival. METHODS: These cases are derived from a prospective cohort of patients with nonsyndromic CHD (n = 422) identified before first surgery. Healthy pediatric controls (n = 500) were obtained from the electronic Medical Records and Genetic Epidemiology Network, and CNV frequency was contrasted for CHD cases and controls. CNVs were determined algorithmically; subsequently screened for >95% overlap between 2 methods, size (>300 kb), quality score, overlap with a gene, and novelty (absent from databases of known, benign CNVs); and separately validated by quantitative polymerase chain reaction. Survival likelihoods for cases were calculated using Cox proportional hazards modeling to evaluate the joint effect of CNV burden and known confounders on transplant-free survival. RESULTS: Children with nonsyndromic CHD had a higher burden of potentially pathogenic CNVs compared with pediatric controls (12.1% vs 5.0%; P = .00016). Presence of a CNV was associated with significantly decreased transplant-free survival after surgery (hazard ratio, 3.42; 95% confidence interval, 1.66-7.09; P = .00090) with confounder adjustment. CONCLUSIONS: We confirm that children with isolated CHD have a greater burden of rare/large CNVs. We report a novel finding that these CNVs are associated with an adjusted 2.55-fold increased risk of death or transplant. These data suggest that CNV burden is an important modifier of survival after surgery for CHD.

Surface microstructure of bitumen characterized by atomic force microscopy.

Bitumen, also called asphalt binder, plays important roles in many industrial applications. It is used as the primary binding agent in asphalt concrete, as a key component in damping systems such as rubber, and as an indispensable additive in paint and ink. Consisting of a large number of hydrocarbons of different sizes and polarities, together with heteroatoms and traces of metals, bitumen displays rich surface microstructures that affect its rheological properties. This paper reviews the current understanding of bitumen's surface microstructures characterized by Atomic Force Microscopy (AFM). Microstructures of bitumen develop to different forms depending on crude oil source, thermal history, and sample preparation method. While some bitumens display surface microstructures with fine domains, flake-like domains, and dendrite structuring, 'bee-structures' with wavy patterns several micrometers in diameter and tens of nanometers in height are commonly seen in other binders. Controversy exists regarding the chemical origin of the 'bee-structures', which has been related to the asphaltene fraction, the metal content, or the crystallizing waxes in bitumen. The rich chemistry of bitumen can result in complicated intermolecular associations such as coprecipitation of wax and metalloporphyrins in asphaltenes. Therefore, it is the molecular interactions among the different chemical components in bitumen, rather than a single chemical fraction, that are responsible for the evolution of bitumen's diverse microstructures, including the 'bee-structures'. Mechanisms such as curvature elasticity and surface wrinkling that explain the rippled structures observed in polymer crystals might be responsible for the formation of 'bee-structures' in bitumen. Despite the progress made on morphological characterization of bitumen using AFM, the fundamental question whether the microstructures observed on bitumen surfaces represent its bulk structure remains to be addressed. In addition, critical technical challenges associated with AFM characterization of bitumen surface structures are discussed, with possible solutions recommended. For future work, combining AFM with other chemical analysis tools that can generate comparable high resolution to AFM would provide an avenue to linking bitumen's chemistry to its microscopic morphological and mechanical properties and consequently benefit the efforts of developing structure-related models for bituminous materials across the different length scales.