Impact of Management Strategy on Feeding and Somatic Growth in Neonates with Symptomatic Tetralogy of Fallot: Results from the Congenital Cardiac Research Collaborative.

OBJECTIVE: To evaluate early growth following primary or staged repair of neonatal symptomatic tetralogy of Fallot (sTOF). STUDY DESIGN: We performed a retrospective, multicenter cohort study of consecutive infants with sTOF who underwent initial intervention at age ≤30 days, from 2005 to 2017. Management strategies were either primary repair or staged repair (ie, initial palliation followed by complete repair). The primary outcome was change in weight-for-age z-score (ΔWAZ) from the initial intervention to age 6 ± 2 months. Secondary outcomes included method and mode of feeding, feeding-related medications, and feeding-related readmissions. Propensity score adjustment was used to account for baseline differences between groups. A secondary analysis was performed comparing patients stratified by the presence of adequate growth (6-month ΔWAZ > -0.5) or inadequate growth (6-month ΔWAZ ≤ -0.5), independent of treatment strategy. RESULTS: The study cohort included 143 primary repair subjects and 240 staged repair subjects. Prematurity was more common in the staged repair group. After adjustment, median ΔWAZ did not differ between treatment groups over the first 6 months of life (primary: -0.43 [IQR, -1.17 to 0.50]; staged: -0.31 [IQR, -1.31 to 0.71]; P = .55). For the entire cohort, ΔWAZ was negative (-0.36; IQR, -1.21 to 0.63). There were no between-group differences in the secondary outcomes. Secondary analysis revealed that the subjects with adequate growth were more likely to be orally fed at initial hospital discharge (P = .04). CONCLUSIONS: In neonates with sTOF, growth trajectory over the first 6 months of life was substandard, irrespective of treatment strategy. Those patients with adequate growth were more likely to be discharged from the index procedure on oral feeds.

Exercise Recommendations in Pediatric HCM: Variation and Influence of Provider Characteristics.

Pediatric Hypertrophic Cardiomyopathy (HCM) is associated with sudden cardiac death (SCD) that can be related to physical activity. Without pediatric specific guidelines, recommendations for activity restriction may be varied. Therefore, our aim is to determine the current practice and variability surrounding exercise clearance recommendations (ER) in pediatric HCM referral centers as well as provider and patient characteristics that influence them. We designed a survey that was distributed to the Pediatric Heart Transplant Study (PHTS) providers and members of the Pediatric and Adult Congenital Electrophysiology Society (PACES) querying provider demographics and patient variables from 2 patient vignettes. The study is a multicenter survey of current practice of specialized providers caring for pediatric HCM patients. Survey of PHTS and PACES providers via email to the respective listservs with a response rate of 28% and 91 overall completing the entire survey after self-identifying as providers for pediatric HCM patients at their center. ER varies for pediatric HCM and is associated with provider training background as well as personal and professional history. Of the 91 providers who completed the survey, 42% (N = 38) trained in pediatric electrophysiology (EP), and 40% (N = 36) in pediatric heart failure (HF). Responses varied and only 53% of providers cleared for mild to moderate activity for the patient in Vignette 1, which is more in line with recent published adult guidelines. ER in both vignettes was significantly associated with type of training background. EP providers were more likely to recommend no restriction (27.8% vs 5.9%) than HF providers even when controlling for provider age and time out of training. Syncope with exercise was deemed "Most Important" by 81% of providers when making ER. ER for pediatric HCM are variable and the majority of providers make ER outside of previously published adult guidelines. Furthermore, ER are influenced by provider background and experience. Further study is needed for risks and benefits of physical activity in this population to inform the development of pediatric specific guidelines.

Comparison of Patent Ductus Arteriosus Stent and Blalock-Taussig Shunt as Palliation for Neonates with Sole Source Ductal-Dependent Pulmonary Blood Flow: Results from the Congenital Catheterization Research Collaborative.

Patent ductus arteriosus (PDA) stenting is an accepted method for securing pulmonary blood flow in cyanotic neonates. In neonates with pulmonary atresia and single source ductal-dependent pulmonary blood flow (SSPBF), PDA stenting remains controversial. We sought to evaluate outcomes in neonates with SSPBF, comparing PDA stenting and surgical Blalock-Taussig shunt (BTS). Neonates with SSPBF who underwent PDA stenting or BTS at the four centers of the Congenital Catheterization Research Collaborative from January 2008 to December 2015 were retrospectively reviewed. Reintervention on the BTS or PDA stent prior to planned surgical repair served as the primary endpoint. Additional analyses of peri-procedural complications, interventions, and pulmonary artery growth were performed. A propensity score was utilized to adjust for differences in factors. Thirty-five patients with PDA stents and 156 patients with BTS were included. The cohorts had similar baseline characteristics, procedural complications, and mortality. Interstage reintervention rates were higher in the PDA stent cohort (48.6% vs. 15.4%, p < 0.001).

Palliation Strategy to Achieve Complete Repair in Symptomatic Neonates with Tetralogy of Fallot.

Neonates with symptomatic tetralogy of Fallot (sTOF) may undergo palliations with varying physiology, namely systemic to pulmonary artery connections (SPC) or right ventricular outflow tract interventions (RVOTI). A comparison of palliative strategies based on the physiology created is lacking. Consecutive sTOF neonates undergoing SPC or RVOTI from 2005-2017 were reviewed from the Congenital Cardiac Research Collaborative. The primary outcome was survival with successful complete repair (CR) by 18 months. A variety of secondary outcomes were assessed including overall survival, hospitalization-related comorbidities, and interstage reinterventions. Propensity score adjustment was utilized to compare treatment strategies. The cohort included 252 SPC (surgical shunt = 226, ductus arteriosus stent = 26) and 68 RVOTI (balloon pulmonary valvuloplasty = 48, RVOT stent = 11, RVOT patch = 9) patients. Genetic syndrome (29 [42.6%] v 75 [29.8%], p = 0.04), weight < 2.5 kg (28 [41.2%] v 68 [27.0%], p = 0.023), bilateral pulmonary artery Z-score < - 2 (19 [28.0%] v 36 [14.3%], p = 0.008), and pre-intervention antegrade flow (48 [70.6%] v 104 [41.3%], p < 0.001) were more common in RVOTI. Significant center differences were noted (p < 0.001). Adjusted survival to CR by 18 months (HR = 0.87, 95% CI = 0.63-1.21, p = 0.41) and overall survival (HR = 2.08, 95% CI = 0.93-4.65, p = 0.074) were similar. RVOTI had increased interstage reintervention (HR = 2.15, 95% CI = 1.36-3.99, p = 0.001). Total anesthesia (243 [213, 277] v 328 [308, 351] minutes, p < 0.001) and cardiopulmonary bypass times (117 [103, 132] v 151 [143, 160] minutes, p < 0.001) favored RVOTI. In this multicenter comparison of physiologic palliation strategies for sTOF, survival to successful CR and overall survival were similar; however, reintervention burden was significantly higher in RVOTI.

Lost but not missing: factors associated with loss of follow-up in a paediatric cardiology clinic.

BACKGROUND: Loss of follow-up is a barrier to providing adequate care to paediatric cardiac patients. The purpose of this study was to determine variables associated with loss of appropriate paediatric cardiology follow-up, including potentially modifiable factors. We hypothesised having earlier recommend follow-up intervals was associated with less likelihood of loss of follow-up. METHODS: We performed a retrospective cohort study of patients >5 years old seen in a large, outpatient paediatric practice from 2013 to 2016. Subjects were considered to be lost to follow-up if they did not have a subsequent outpatient encounter by 6 months after their recommend follow-up time interval. RESULTS: Of the 8940 eligible patients, 45.9% were lost to follow-up. Recommended follow-up interval of 1 year was associated with less loss of follow-up (41.4%) as compared to 2-year intervals (51.6%) and 3 years (55.7%) (p < 0.001 for both). Other significant predictors of loss of follow-up included less severe heart disease, older age, and non-Hispanic Black race/ethnicity. Sex and payor type were not significant predictors. In the stratified analyses by severity of disease and age, longer recommended follow-up time was associated with greater loss of follow-up among all severity and age categories. CONCLUSIONS: Almost half of the patients in our cohort did not return to clinic within the recommended timeline. Shorter follow-up time was associated with less loss of follow-up among all categories of disease severity and age groups. Recommending shorter follow-up intervals may be one initiative for paediatric cardiologists to improve rates of follow-up.

Impact of the COVID pandemic on quality measures in a pediatric echocardiography lab.

Background: The COVID pandemic necessitated an altered approach to transthoracic echocardiography, especially in COVID cases. Whether this has effected echocardiography lab quality is unknown. Objectives: We sought to determine whether echocardiography lab quality measures during the COVID pandemic were different from those prior to the pandemic and whether quality and comprehensiveness of echocardiograms performed during the pandemic was different between COVID and non-COVID patients. Methods: The four quality measures (diagnostic errors, appropriateness of echocardiogram, American College of Cardiology Image Quality metric and Comprehensive Exam metric in structurally normal hearts) reported quarterly in our lab were compared between two quarters during COVID (2020) and pre-COVID (2019). Each component of these metrics was also assessed in randomly selected echocardiograms in COVID patients and compared to non-COVID echocardiograms. Results: For non-COVID echocardiograms, the image quality metric did not change between 2019 and 2020 and the comprehensive exam metric improved. Diagnostic error rate did not change, and appropriateness of echocardiogram indications improved. When COVID and non-COVID echocardiograms were compared, the image quality metric and comprehensiveness exam metric were lower for COVID cases (image quality mean 21.3/23 for non-COVID, 18.6/23 for COVID, p < 0.001 and comprehensive exam mean 29.5/30 for non-COVID, 27.7/39 for COVID, p < 0.001). In particular, systemic and pulmonary veins, pulmonary arteries and aortic arch were not adequately imaged in COVID patients. For studies in which a follow-up echocardiogram was available, no new pathology was found. Conclusions: At our center, though diagnostic error rate did not change during the pandemic and the proportion of echocardiograms ordered for appropriate indications increased, imaging quality in COVID patients was compromised, especially for systemic and pulmonary veins, pulmonary arteries and arch. Though no new pathology was noted on the small number of patients who had follow-up studies, we are paying careful attention to these structures to avoid diagnostic errors going forward.

Total vascular resistance increases during volume-unloading in asymptomatic single ventricle patients.

OBJECTIVE: While the surgical stages of single ventricle (SV) palliation serve to separate pulmonary venous and systemic venous return, and to volume-unload the SV, staged palliation also results in transition from parallel to series circulation, increasing total vascular resistance. How this transition affects pressure loading of the SV is as yet unreported. METHODS: We performed a retrospective chart review of Stage I, II, and III cardiac catheterization (CC) and echocardiographic data from 2001-2017 in all SV pts, with focus on systemic, pulmonary, and total vascular resistance (SVR, PVR, TVR respectively). Longitudinal analyses were performed with log-transformed variables. Effects of SVR-lowering medications were analyzed using Wilcoxon rank-sum testing. RESULTS: There were 372 total patients who underwent CC at a Stage I (median age of 4.4 months, n=310), Stage II (median age 2.7 years, n = 244), and Stage III (median age 7.3 years, n = 113). Total volume loading decreases with progression to Stage III (P< 0.001). While PVR gradually increases from Stage II to Stage III, and SVR increases from Stage I to Stage III, TVR dramatically increases with progress towards series circulation. TVR was not affected by use of systemic vasodilator therapy. TVR, PVR, SVR, and CI did not correlate with indices of SV function at Stage III. CONCLUSIONS: TVR steadily increases with an increasing contribution from SVR over progressive stages. TVR was not affected by systemic vasodilator agents. TVR did not correlate with echo-based indices of SV function. Further studies are needed to see if modulating TVR can improve exercise tolerance and outcomes.

Multisystem Inflammatory Syndrome in Children: Survey of Protocols for Early Hospital Evaluation and Management.

OBJECTIVE: To describe the similarities and differences in the evaluation and treatment of multisystem inflammatory syndrome in children (MIS-C) at hospitals in the US. STUDY DESIGN: We conducted a cross-sectional survey from June 16 to July 16, 2020, of US children's hospitals regarding protocols for management of patients with MIS-C. Elements included characteristics of the hospital, clinical definition of MIS-C, evaluation, treatment, and follow-up. We summarized key findings and compared results from centers in which >5 patients had been treated vs those in which ≤5 patients had been treated. RESULTS: In all, 40 centers of varying size and experience with MIS-C participated in this protocol survey. Overall, 21 of 40 centers required only 1 day of fever for MIS-C to be considered. In the evaluation of patients, there was often a tiered approach. Intravenous immunoglobulin was the most widely recommended medication to treat MIS-C (98% of centers). Corticosteroids were listed in 93% of protocols primarily for moderate or severe cases. Aspirin was commonly recommended for mild cases, whereas heparin or low molecular weight heparin were to be used primarily in severe cases. In severe cases, anakinra and vasopressors frequently were recommended; 39 of 40 centers recommended follow-up with cardiology. There were similar findings between centers in which >5 patients vs ≤5 patients had been managed. Supplemental materials containing hospital protocols are provided. CONCLUSIONS: There are many similarities yet key differences between hospital protocols for MIS-C. These findings can help healthcare providers learn from others regarding options for managing MIS-C.

Lead age as a predictor for failure in pediatrics and congenital heart disease.

BACKGROUND: Pediatric and congenital heart disease (CHD) patients have a high rate of transvenous (TV) lead failure. OBJECTIVE: To determine whether TV lead age can aid risk assessment for lead failure to guide the decision of whether a lead should be replaced or reused at the time of a generator change. METHODS: Retrospective cohort study of patients <21 years old undergoing TV device implant from 2000 to 2014 at our institution. Patient, device, and lead variables were collected. Leads were compared in groups based on how many generator changes were completed. RESULTS: A total of 393 leads in 257 patients met inclusion criteria, 60 leads failed (15%). Failed leads were more likely to have not yet undergone generator change (p = .048). CHD (p = .045), Tendril lead type (p = .02) and silicone insulation (p = .02) were associated with failure. In multivariate analysis, younger leads (p = .022), number of generator changes (p = .003), CHD (p = .005) and silicone insulation (p = .004) remained significant while Tendril lead type did not (p = .052). Survival curves show an early decline around 4 years. CONCLUSIONS: Lead failure rate in pediatric and CHD patients is high. Leads that have not yet undergone a generator change were more likely to fail in this cohort. The strategy of serial replacement based on lead age needs further research to justify in this population.

Risk Factors for Adverse Events in Children with Pulmonary Hypertension Undergoing Cardiac Catheterization.

Pulmonary hypertension (PH) can lead to progressive heart failure with high morbidity and mortality. Cardiac catheterization (CC) is the gold standard for diagnosis and response to vasodilatory medications. The invasive nature of CC and associated anesthesia predispose this patient population to adverse events including death. Catheterization records were queried from 1/1/2011 to 10/31/2016. Patients with PH, defined as pulmonary vascular resistance (PVR) greater than 3 WU m2, pulmonary artery pressure above 20 mmHg, and pulmonary wedge pressure less than or equal to 15 mmHg, who underwent hemodynamic CC were included in this retrospective study. Both patients with and without congenital heart disease were included. There were 198 CC in 191 patients. Adverse events (n = 28, 14.1%) included cardiac arrest, increased respiratory support requiring ICU care, PH crisis, bradycardia/hypotension requiring intervention, and arrhythmias. Odds of an adverse event increased by 22% for every 15-min increase in procedure times (OR 1.22, CI 1.01-1.39, p = 0.002) and were significantly increased for procedures longer than 80 min (OR 3.75, CI 1.56-9.00, p = 0.007) (Fig. 1). Patients with an adverse event had higher mean pulmonary artery pressures while breathing oxygen (43 [35-58] versus 34 [27-44] mmHg, p = 0.017) and oxygen with inhaled nitric oxide (37 [32-56] versus 32 [25-40] mmHg, p = 0.026). Females carried more risk than males (OR 3.88, CI 1.44-10.40, p = 0.007). Younger age, medication regimens, prematurity, and genetic disease did not carry an increased risk. Adverse events are common in pediatric patients with PH undergoing CC. The risk of adverse events correlates with greater procedure times and higher mean pulmonary artery pressure. Minimizing procedure time may improve patient outcomes.

Impact of Treatment Strategy on Outcomes in Isolated Pulmonary Artery of Ductal Origin.

Isolated pulmonary artery (PA) of ductal origin (IPADO) is a rare cardiac defect which requires surgical repair, with or without preceding palliation. We sought to determine the impact of treatment strategy on outcomes. Retrospective study of consecutive patients with IPADO that underwent staged or primary repair from 1/05 to 9/16 at 6 Congenital Cardiac Research Collaborative centers. Patients with single ventricle physiology, major aortopulmonary collaterals, or bilateral IPADO were excluded. Primary outcome was isolated PA z-score at late follow-up. Secondary outcomes included PA symmetry index (isolated:confluent PA diameter) and reintervention burden. Propensity score adjustment was used to account for baseline differences. Of 60 patients in the study cohort, 26 (43%) underwent staged and 34 (57%) primary repair. The staged and primary repair groups differed in weight at diagnosis and presence of other heart disease but not in baseline PA dimensions. Staged patients underwent ductal stent (n = 16) or surgical shunt (n = 10) placement followed by repair at 210 vs. 21 days in the primary repair group (p < 0.001). At median follow-up of 4.5 years post-repair, after adjustment, isolated PA z-score (- 0.74 [- 1.75, - 0.26] vs. - 1.95 [- 2.91, - 1.59], p = 0.012) and PA symmetry index (0.81 [0.49, 1.0] vs. 0.55 [0.48, 0.69], p = 0.042) significantly favored the staged repair group. Freedom from PA reintervention was not different between groups (adjusted HR 0.78 [0.41, 1.48]; p = 0.445). A staged approach to repair of IPADO is associated with superior isolated PA size and symmetry at late follow-up. Consideration should be given to initial palliation in IPADO patients, when feasible.

Racial and ethnic differences in response to treatment for Marfan syndrome.

OBJECTIVE: To determine whether racial/ethnic differences exist for the treatment of Marfan syndrome aortopathy. The 2014 Pediatric Heart Network randomised trial of losartan versus atenolol in Marfan syndrome paediatric and young adult patients showed no treatment differences in the rate of aortic root growth over 3 years; however, they did not examine racial/ethnic differences, and recent data suggest that angiotensin receptor blockers may have different pharmacologic effects in different racial/ethnic populations. METHODS: We performed a secondary analysis of public-use data from the Pediatric Heart Network randomised trial comparing the differences by race/ethnicity (non-Hispanic White, non-Hispanic Black, and Hispanic patients) amongst the treatment groups for the primary outcome of rate of aortic root enlargement by z score and secondary outcome of rate of change of absolute diameter of aortic root, z score and absolute diameter of ascending aorta, and blood pressure changes. RESULTS: For aortic root enlargement by z score amongst non-Hispanic White patients, patients on losartan exhibited an annual z score change of -0.090 ± 0.016, compared to -0.146 ± 0.015 for those on atenolol (p = 0.01), favouring atenolol. For Hispanic and non-Hispanic Black patients, there was no difference in primary or secondary outcomes between treatment groups. CONCLUSION: Non-Hispanic White patients had a small, but statistically significantly greater decrease in aortic root z score favouring atenolol over losartan. There were no significant differences amongst Hispanic or non-Hispanic Black patients, which may be due to relatively small size numbers. These findings may have important implications for medication selection by race/ethnicity in Marfan syndrome patients, which has not previously been evaluated in studies.

N-terminal pro-B-type-natriuretic peptide as a screening tool for pulmonary hypertension in the paediatric population.

BACKGROUND: Although cardiac catheterisation (cath) is the diagnostic test for pulmonary hypertension, it is an invasive procedure. Echocardiography (echo) is commonly used for the non-invasive diagnosis of pulmonary hypertension but maybe limited by lack of adequate signals. Therefore, emphasis has been placed on biomarkers as a potential diagnostic tool. No prior paediatric studies have simultaneously compared N-terminal pro-B-type-natriuretic peptide (NTproBNP) with cath/echo as a potential diagnostic tool. The aim of this study was to determine if NTproBNP was a reliable diagnostic tool for pulmonary hypertension in this population. METHODS: Patients were divided into Study (echo evidence/established diagnosis of pulmonary hypertension undergoing cath) and Control (cath for small atrial septal defect/patent ductus arteriosus and endomyocardial biopsy post cardiac transplant) groups. NTproBNP, cath/echo data were obtained. RESULTS: Thirty-one patients met inclusion criteria (10 Study, 21 Control). Median NTproBNP was significantly higher in the Study group. Echo parameters including transannular plane systolic excursion z scores, pulmonary artery acceleration time and right ventricular fractional area change were lower in the Study group and correlated negatively with NTproBNP. Receiver operation characteristic curve analysis demonstrated NTproBNP > 389 pg/ml was 87% specific for the diagnosis of pulmonary hypertension with the addition of pulmonary artery acceleration time improving the specificity. CONCLUSIONS: NTproBNP may be a valuable adjunctive diagnostic tool for pulmonary hypertension in the paediatric population. Echo measures of transannular plane systolic excursion z score, pulmonary artery acceleration time and right ventricular fractional area change had negative correlations with NTproBNP. The utility of NTproBNP as a screening tool for pulmonary hypertension requires validation in a population with unknown pulmonary hypertension status.

Data quality methods through remote source data verification auditing: results from the Congenital Cardiac Research Collaborative.

BACKGROUND: Multicentre research databases can provide insights into healthcare processes to improve outcomes and make practice recommendations for novel approaches. Effective audits can establish a framework for reporting research efforts, ensuring accurate reporting, and spearheading quality improvement. Although a variety of data auditing models and standards exist, barriers to effective auditing including costs, regulatory requirements, travel, and design complexity must be considered. MATERIALS AND METHODS: The Congenital Cardiac Research Collaborative conducted a virtual data training initiative and remote source data verification audit on a retrospective multicentre dataset. CCRC investigators across nine institutions were trained to extract and enter data into a robust dataset on patients with tetralogy of Fallot who required neonatal intervention. Centres provided de-identified source files for a randomised 10% patient sample audit. Key auditing variables, discrepancy types, and severity levels were analysed across two study groups, primary repair and staged repair. RESULTS: Of the total 572 study patients, data from 58 patients (31 staged repairs and 27 primary repairs) were source data verified. Amongst the 1790 variables audited, 45 discrepancies were discovered, resulting in an overall accuracy rate of 97.5%. High accuracy rates were consistent across all CCRC institutions ranging from 94.6% to 99.4% and were reported for both minor (1.5%) and major discrepancies type classifications (1.1%). CONCLUSION: Findings indicate that implementing a virtual multicentre training initiative and remote source data verification audit can identify data quality concerns and produce a reliable, high-quality dataset. Remote auditing capacity is especially important during the current COVID-19 pandemic.

Cardiomegaly on chest radiographs as a predictor of heart disease in the pediatric population.

BACKGROUND: Cardiomegaly on chest radiographs (CXR) in pediatric patients leads to multiple tests. We aimed to determine the positive predictive value (PPV) of cardiomegaly on CXR in predicting subsequent heart disease and to assess the utility of obtaining a B-type Natriuretic Peptide level (BNP) and/or electrocardiogram (EKG) in such patients. We hypothesized that an echocardiogram may not be appropriate in all cases of cardiomegaly on CXR, particularly in a patient with a normal EKG and BNP level. METHODS: We performed a retrospective cohort study of pediatric patients with cardiomegaly on their initial CXR between January 2015-December 2017. Patients without a subsequent echocardiogram or known congenital heart disease were excluded. A patient was deemed to have heart disease if they had structural abnormalities, functional abnormalities or a pericardial effusion on echocardiogram. The PPV of CXR and the PPV/NPV of the other tests (EKG, BNP) were calculated using contingency tables. RESULTS: Four hundred and eighty nine patients met inclusion criteria. The PPV of cardiomegaly on CXR alone without any other diagnostic testing in predicting subsequent heart disease was 15%. The PPV increased if there was either an abnormal EKG or a BNP >100 pg/ml and further increased if both of these were present. The PPV values were higher in patients <1 year of age. CONCLUSIONS: Cardiomegaly on CXR can often predict the presence of heart disease, particularly in infants. Further testing with EKG and BNP can better predict who may have heart disease, but it may not eliminate the need for echocardiography.

T Cells Play a Causal Role in Diastolic Dysfunction during Uremic Cardiomyopathy.

BACKGROUND: Uremic cardiomyopathy, characterized by left ventricular hypertrophy, diastolic dysfunction, and impaired myocardial strain, contributes to increased cardiovascular mortality in patients with CKD. Emerging evidence suggests a pathogenic role for T cells during chronic heart failure. METHODS: To determine whether T cells contribute to uremic cardiomyopathy pathogenesis, we modeled this condition by inducing CKD via 5/6th nephrectomy in mice. We used flow cytometry to assess expression of markers of T cell memory or activation by lymphocytes from CKD mice and controls, as well as lymphocyte capacity for cytokine production. Flow cytometry was also used to quantify immune cells isolated from heart tissue. To test effects of T cell depletion on cardiac function, we gave CKD mice anti-CD3 antibody injections to deplete T cells and compared heart function (assessed by echocardiography) with that of controls. Finally, we correlated T cell phenotypes with structural and functional measures on clinically acquired echocardiograms in children with CKD. RESULTS: Mice with CKD accumulated T cells bearing markers of memory differentiation (CD44hi) and activation (PD-1, KLRG1, OX40), as reported previously in human CKD. In addition, mice with CKD showed T cells infiltrating the heart. T cell depletion significantly improved both diastolic function and myocardial strain in CKD mice without altering hypertension or degree of renal dysfunction. In children with CKD, increasing frequency of T cells bearing activation markers PD-1 and/or CD57 was associated with worsening diastolic function on echocardiogram. CONCLUSIONS: CKD results in an accumulation of proinflammatory T cells that appears to contribute to myocardial dysfunction.

Recurrent single echo beats after cryoablation of atrioventricular nodal reentrant tachycardia: The pediatric population.

BACKGROUND: Cryoablation for atrioventricular nodal reentrant tachycardia (AVNRT) is effective and safe with a reported limitation of lower success and higher recurrence rates. We have observed cases in which slow pathway conduction was eliminated as demonstrated by atrial extra-stimulus testing within 1 min of cryo-energy delivery but returned following tissue rewarming. Frequently, slow pathway conduction persisted despite multiple acutely successful lesions over a broad anatomic region. We aimed to determine if return of slow pathway conduction after elimination during cryoablation represents a risk for recurrent AVNRT with the same intermediate term results as slow pathway ablation. We hypothesize that remnant single echo beats in the absence of sustained slow pathway conduction and inducible AVNRT is an acceptable end point after clear slow pathway elimination during cryoablation. METHODS: Retrospective chart review of patients undergoing attempted slow pathway ablation for AVNRT using solely cryoablation between January 2015-January 2018. RESULTS: Forty-four patients met inclusion criteria with at-least 2 features of dual AVN physiology. 19 patients had return of slow pathway conduction shortly after clear elimination during cryoablation (Group A) while 25 did not (Group B). All in Group A had recurrent single echo beats but none had sustained slow pathway conduction at the end of the procedure nor AVNRT recurrence at 1 year. CONCLUSION: Recurrent single echo beats with absent sustained slow pathway conduction and non-inducible AVNRT may be an acceptable endpoint for slow pathway ablation of AVNRT using cryoablation when there is elimination of slow pathway demonstrated during energy delivery.

Comparison Between Patent Ductus Arteriosus Stent and Modified Blalock-Taussig Shunt as Palliation for Infants With Ductal-Dependent Pulmonary Blood Flow: Insights From the Congenital Catheterization Research Collaborative.

BACKGROUND: Infants with ductal-dependent pulmonary blood flow may undergo palliation with either a patent ductus arteriosus (PDA) stent or a modified Blalock-Taussig (BT) shunt. A balanced multicenter comparison of these 2 approaches is lacking. METHODS: Infants with ductal-dependent pulmonary blood flow palliated with either a PDA stent or a BT shunt from January 2008 to November 2015 were reviewed from the 4 member centers of the Congenital Catheterization Research Collaborative. Outcomes were compared by use of propensity score adjustment to account for baseline differences between groups. RESULTS: One hundred six patients with a PDA stent and 251 patients with a BT shunt were included. The groups differed in underlying anatomy (expected 2-ventricle circulation in 60% of PDA stents versus 45% of BT shunts; P=0.001) and presence of antegrade pulmonary blood flow (61% of PDA stents versus 38% of BT shunts; P<0.001). After propensity score adjustment, there was no difference in the hazard of the primary composite outcome of death or unplanned reintervention to treat cyanosis (hazard ratio, 0.8; 95% confidence interval [CI], 0.52-1.23; P=0.31). Other reinterventions were more common in the PDA stent group (hazard ratio, 29.8; 95% CI, 9.8-91.1; P<0.001). However, the PDA stent group had a lower adjusted intensive care unit length of stay (5.3 days [95% CI, 4.2-6.7] versus 9.19 days [95% CI, 7.9-10.6]; P<0.001), a lower risk of diuretic use at discharge (odds ratio, 0.4; 95% CI, 0.25-0.64; P<0.001) and procedural complications (odds ratio, 0.4; 95% CI, 0.2-0.77; P=0.006), and larger (152 mm2/m2 [95% CI, 132-176] versus 125 mm2/m2 [95% CI, 113-138]; P=0.029) and more symmetrical (symmetry index, 0.84 [95% CI, 0.8-0.89] versus 0.77 [95% CI, 0.75-0.8]; P=0.008] pulmonary arteries at the time of subsequent surgical repair or last follow-up. CONCLUSIONS: In this multicenter comparison of palliative PDA stent and BT shunt for infants with ductal-dependent pulmonary blood flow adjusted for differences in patient factors, there was no difference in the primary end point, death or unplanned reintervention to treat cyanosis. However, other markers of morbidity and pulmonary artery size favored the PDA stent group, supporting PDA stent as a reasonable alternative to BT shunt in select patients.

Thromboprophylaxis strategies for children with single-ventricle circulations (superior or total cavo-pulmonary connections) after stent implantation.

OBJECTIVE: To define optimal thromboprophylaxis strategy after stent implantation in superior or total cavopulmonary connections. BACKGROUND: Stent thrombosis is a rare complication of intravascular stenting, with a perceived higher risk in single-ventricle patients. METHODS: All patients who underwent stent implantation within superior or total cavopulmonary connections (caval vein, innominate vein, Fontan, or branch pulmonary arteries) were included. Cohort was divided into aspirin therapy alone versus advanced anticoagulation, including warfarin, enoxaparin, heparin, or clopidogrel. Primary endpoint was in-stent or downstream thrombus, and secondary endpoints included bleeding complications. RESULTS: A total of 58 patients with single-ventricle circulation underwent 72 stent implantations. Of them 14 stents (19%) were implanted post-superior cavopulmonary connection and 58 (81%) post-total cavopulmonary connection. Indications for stenting included vessel/conduit stenosis (67%), external compression (18%), and thrombotic occlusion (15%). Advanced anticoagulation was prescribed for 32 (44%) patients and aspirin for 40 (56%) patients. Median follow up was 1.1 (25th-75th percentile, 0.5-2.6) years. Echocardiograms were available in 71 patients (99%), and advanced imaging in 44 patients (61%). Thrombosis was present in two patients on advanced anticoagulation (6.3%) and none noted in patients on aspirin (p = 0.187). Both patients with in-stent thrombus underwent initial stenting due to occlusive left pulmonary artery thrombus acutely post-superior cavopulmonary connection. There were seven (22%) significant bleeding complications for advanced anticoagulation and none for aspirin (p < 0.001). CONCLUSIONS: Antithrombotic strategy does not appear to affect rates of in-stent thrombus in single-ventricle circulations. Aspirin alone may be sufficient for most patients undergoing stent implantation, while pre-existing thrombus may warrant advanced anticoagulation.

Improving paediatric cardiologists' awareness about the needs of childhood cancer survivors: results of a single-centre directed educational initiative.

BACKGROUND: Cardiovascular disease is a leading cause of morbidity and mortality in childhood cancer survivors. Cardiologists must be aware of risk factors and long-term follow-up guidelines, which have historically been the purview of oncologists. Little is known about paediatric cardiologists' knowledge regarding the cardiotoxicity of cancer treatment and how to improve this knowledge. METHODS: A total of 58 paediatric cardiologists anonymously completed a 21-question, web-based survey focused on four cardio-oncology themes: cancer treatment-related risk factors (n = 6), patient-related risk factors (n = 6), recommended surveillance (n = 3), and cardiac-specific considerations (n = 6). Following the baseline survey, a multi-disciplinary team of paediatric cardiologists and cancer survivor providers developed an in-person and web-based educational intervention. A post-intervention survey was conducted 5 months later. RESULTS: The response rate was 41/58 (70.7%) pre-intervention and 30/58 (51.7%) post-intervention. On the baseline survey, the percentage of correct answers was 68.8 ± 10.3%, which improved to 79.2 ± 16.2% after the intervention (p = 0.009). The theme with the most profound knowledge deficit was surveillance; however, it also had the greatest improvement after the intervention (49.6 ± 26.7 versus 66.7 ± 27.7% correct, p = 0.025). Individual questions with the largest per cent improvement pertained to risk of cardiac dysfunction with time since treatment (52.4 versus 93.1%, p = 0.002) and the role of dexrazoxane (48.8 versus 82.8%, p = 0.020). CONCLUSION: Specific knowledge deficits about the care of paediatric cancer survivors were identified amongst cardiologists using a web-based survey. Knowledge of surveillance was initially lowest but improved the most after an educational intervention. This highlights the need for cardio-oncology-based educational initiatives among paediatric cardiologists.