Extracardiac Manifestations Fail to Predict the Severity of Cardiac Phenotype in Children and Young Adults with Marfan Syndrome.

We performed a secondary analysis of the Pediatric Heart Network (PHN) Marfan Trial public-use database to evaluate associations between extracardiac features and cardiac and aortic phenotypes in study participants. Aortic aneurysm phenotype was defined as aortic root Z-score ≥4.5, aortic root growth rate ≥75th percentile, aortic dissection, and aortic surgery. Severe cardiac phenotype was defined as aortic dissection, aortic Z-score ≥4.5, aortic valve surgery, at least moderate mitral regurgitation, mitral valve surgery, left ventricular dysfunction, or death. Extracardiac manifestations were characterized by specific organ system involvement and by a novel aggregate extracardiac score (AES) that was created for this study based on the original Ghent nosology. Mixed effects logistic regression analysis compared AES and systems involvement to outcomes. Of 608 participants (60% male), the median age at enrollment was 10.8 years (interquartile range: 6, 15.4). Aortic aneurysm phenotype was observed in 71% of participants and 64% had severe cardiac phenotype. On univariable analysis, skeletal (OR: 1.95, 95% CI: 1.01, 3.72; p = 0.05), skin manifestation (OR: 1.62, 95% CI: 1.13, 2.34; p = 0.01) and AES (OR: 1.17, 95% CI: 1.02, 1.34; p = 0.02) were associated with aortic aneurysm phenotype but were not significant in multivariable analysis. There was no association between extracardiac manifestations and severe cardiac phenotype. Thus, the severity of cardiac manifestations in Marfan syndrome (MFS) was independent of extracardiac phenotype and AES. Severity of extracardiac involvement did not appear to be a useful clinical marker for cardiovascular risk-stratification in this cohort of children and young adults with MFS.

Cardiac Magnetic Resonance Imaging to Determine Single Ventricle Function in a Pediatric Population is Feasible in a Large Trial Setting: Experience from the Single Ventricle Reconstruction Trial Longitudinal Follow up.

The Single Ventricle Reconstruction (SVR) Trial was a randomized prospective trial designed to determine survival advantage of the modified Blalock-Taussig-Thomas shunt (BTTS) vs the right ventricle to pulmonary artery conduit (RVPAS) for patients with hypoplastic left heart syndrome. The primary aim of the long-term follow-up (SVRIII) was to determine the impact of shunt type on RV function. In this work, we describe the use of CMR in a large cohort follow up from the SVR Trial as a focused study of single ventricle function. The SVRIII protocol included short axis steady-state free precession imaging to assess single ventricle systolic function and flow quantification. There were 313 eligible SVRIII participants and 237 enrolled, ages ranging from 10 to 12.5 years. 177/237 (75%) participants underwent CMR. The most common reasons for not undergoing CMR exam were requirement for anesthesia (n = 14) or ICD/pacemaker (n = 11). A total of 168/177 (94%) CMR studies were diagnostic for RVEF. Median exam time was 54 [IQR 40-74] minutes, cine function exam time 20 [IQR 14-27] minutes, and flow quantification time 18 [IQR 12-25] minutes. There were 69/177 (39%) studies noted to have intra-thoracic artifacts, most common being susceptibility artifact from intra-thoracic metal. Not all artifacts resulted in non-diagnostic exams. These data describe the use and limitations of CMR for the assessment of cardiac function in a prospective trial setting in a grade-school-aged pediatric population with congenital heart disease. Many of the limitations are expected to decrease with the continued advancement of CMR technology.

Coronary artery dilation associated with bicuspid and unicuspid aortic valve disease in children: a series of 17 patients.

INTRODUCTION: Coronary artery dilation associated with bicuspid/unicuspid aortic valves is described in adults with limited data in children. We aimed to describe the clinical course of children with bicuspid/unicuspid aortic valves and coronary dilation including coronary Z-score changes over time, association of coronary changes with aortic valve anatomy/function, and complications. MATERIALS AND METHODS: Institutional databases were searched for children ≤18 years with both bicuspid/unicuspid aortic valves and coronary dilation (1/2006-6/2021). Kawasaki disease and isolated supra-/subvalvar aortic stenosis were excluded. Statistics were descriptive with associations measured by Fisher's exact test and overlapping 83.7% confidence intervals. RESULTS: Of 17 children, bicuspid/unicuspid aortic valve was diagnosed at birth in 14 (82%). Median age at coronary dilation diagnosis was 6.4 years (range: 0-17.0). Aortic stenosis was present in 14 (82%) [2 (14%) moderate, 8 (57%) severe]; 10 (59%) had aortic regurgitation; 8 (47%) had aortic dilation. The right coronary was dilated in 15 (88%), left main in 6 (35%), and left anterior descending in 1 (6%) with no relationship between leaflet fusion pattern or severity of aortic regurgitation/stenosis on coronary Z-score. Follow-up evaluations were available for 11 (mean 9.3 years, range 1.1-14.8) with coronary Z-scores increasing in 9/11 (82%). Aspirin was used in 10 (59%). There were no deaths or coronary artery thrombosis. DISCUSSION: In children with bicuspid/unicuspid aortic valves and coronary dilation, the right coronary artery was most frequently involved. Coronary dilation was observed in early childhood and frequently progressed. Antiplatelet medication use was inconsistent, but no child died nor developed thrombosis.

Results of the FUEL Trial.

BACKGROUND: The Fontan operation creates a total cavopulmonary connection, a circulation in which the importance of pulmonary vascular resistance is magnified. Over time, this circulation leads to deterioration of cardiovascular efficiency associated with a decline in exercise performance. Rigorous clinical trials aimed at improving physiology and guiding pharmacotherapy are lacking. METHODS: The FUEL trial (Fontan Udenafil Exercise Longitudinal) was a phase III clinical trial conducted at 30 centers. Participants were randomly assigned udenafil, 87.5 mg twice daily, or placebo in a 1:1 ratio. The primary outcome was the between-group difference in change in oxygen consumption at peak exercise. Secondary outcomes included between-group differences in changes in submaximal exercise at the ventilatory anaerobic threshold, the myocardial performance index, the natural log of the reactive hyperemia index, and serum brain-type natriuretic peptide. RESULTS: Between 2017 and 2019, 30 clinical sites in North America and the Republic of Korea randomly assigned 400 participants with Fontan physiology. The mean age at randomization was 15.5±2 years; 60% of participants were male, and 81% were white. All 400 participants were included in the primary analysis with imputation of the 26-week end point for 21 participants with missing data (11 randomly assigned to udenafil and 10 to placebo). Among randomly assigned participants, peak oxygen consumption increased by 44±245 mL/min (2.8%) in the udenafil group and declined by 3.7±228 mL/min (-0.2%) in the placebo group (P=0.071). Analysis at ventilatory anaerobic threshold demonstrated improvements in the udenafil group versus the placebo group in oxygen consumption (+33±185 [3.2%] versus -9±193 [-0.9%] mL/min, P=0.012), ventilatory equivalents of carbon dioxide (-0.8 versus -0.06, P=0.014), and work rate (+3.8 versus +0.34 W, P=0.021). There was no difference in change of myocardial performance index, the natural log of the reactive hyperemia index, or serum brain-type natriuretic peptide level. CONCLUSIONS: In the FUEL trial, treatment with udenafil (87.5 mg twice daily) was not associated with an improvement in oxygen consumption at peak exercise but was associated with improvements in multiple measures of exercise performance at the ventilatory anaerobic threshold. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02741115.

Longitudinal study of anthropometry in Fontan survivors: Pediatric Heart Network Fontan study.

BACKGROUND: Growth abnormalities in single-ventricle survivors may reduce quality of life (QoL) and exercise capacity. METHODS: This multicenter, longitudinal analysis evaluated changes in height and body mass index (BMI) compared to population norms and their relationship to mortality, ventricular morphology, QoL, and exercise capacity in the Pediatric Heart Network Fontan studies. RESULTS: Fontan 1 (F1) included 546 participants (12 ±â€¯3.4 years); Fontan 2 (F2), 427 (19 ±â€¯3.4 years); and Fontan 3 (F3), 362 (21 ±â€¯3.5 years), with ~60% male at each time point. Height z-score was -0.67 ±â€¯-1.27, -0.60 ±â€¯1.34, and- 0.43 ±â€¯1.14 at F1-F3, lower compared to norms at all time points (P ≤ .001). BMI z-score was similar to population norms. Compared to survivors, participants who died had lower height z-score (P ≤ .001). Participants with dominant right ventricle (n = 112) had lower height z-score (P ≤ .004) compared to dominant left (n = 186) or mixed (n = 64) ventricular morphologies. Higher height z-score was associated with higher Pediatric Quality of Life Inventory for the total score (slope = 2.82 ±â€¯0.52; P ≤ .001). Increase in height z-score (F1 to F3) was associated with increased oxygen consumption (slope = 2.61 ±â€¯1.08; P = .02), whereas, for participants >20 years old, an increase in BMI (F1 to F3) was associated with a decrease in oxygen consumption (slope = -1.25 ±â€¯0.33; P ≤ .001). CONCLUSIONS: Fontan survivors, especially those with right ventricular morphology, are shorter when compared to the normal population but have similar BMI. Shorter stature was associated with worse survival. An increase in height z-score over the course of the study was associated with better QoL and exercise capacity; an increase in BMI was associated with worse exercise capacity.

Thrombotic microangiopathy following heart transplant in pediatric Danon disease.

This case describes an uncommon acute complication of diffuse thrombotic angiopathy and associated aHUS/TTP in an 11-year-old girl with Danon disease who underwent orthotopic heart transplant. Shortly after transplant, despite an uncomplicated operative course, the patient developed severe kidney injury and progressive altered mental status, culminating in cerebral edema, brain herniation, and death. She had received a single dose of tacrolimus (FK506) and a single dose of antithymocyte globulin. Sources of progressive somnolence, including oversedation from impaired renal clearance of opiates, and severe myopathy as has been previously described in Danon disease, were ruled out, and the patient continued to decline. Initial brain CT scan early after transplant showed no signs of cerebral edema, but repeat CT indicated severe cerebral edema. Based on autopsy, diffuse thrombotic angiopathy, with signs of hemolytic anemia with schistocytes, was likely responsible for her deterioration in the broader condition of aHUS/TTP.

Mortality and Resource Use Following Cardiac Interventions in Children with Trisomy 13 and Trisomy 18 and Congenital Heart Disease.

We sought to evaluate the mortality, risk factors for mortality, and resource utilization following cardiac interventions in trisomy 13 (T13) and 18 (T18) children. All T13 and T18 children who underwent a cardiac intervention from January 1999 to March 2015 were identified from the Pediatric Health Information System database. Data collected included demographics, type of congenital heart disease (CHD), cardiac interventions, comorbidities, length of stay (LOS), hospital charges, and deaths (within 30 days). Logistic regression analysis was used to determine factors associated with mortality. There were 49 (47% females) T13 and 140 (67% females) T18 subjects. The two cohorts were similar in distribution for race, geographic region, insurance type, and median household income. The most common CHD in both groups was a shunt lesion followed by conotruncal defects. Compared to T18, the T13 cohort had higher mortality (29% vs. 12%), tracheostomies (12% vs. 4%), gastrostomies (18% vs. 6%), and overall resource use (P < 0.05 for all). White race (OR 0.23, 95% CI 0.06-0.81) in T13 and older age (in weeks) at surgery in T18 (OR 0.75, 95% CI 0.64-0.86) were associated with lower mortality. A select group of T13 and T18 CHD patients can undergo successful cardiac interventions, albeit with a higher mortality and resource use. T13 patients have higher mortality and resource use compared to T18. In T13 and T18 patients, interventions for CHD may be an acceptable and ethical option following a careful individualized selection and counseling by a team of experts.

Respiratory Testing and Hospital Outcomes in Asymptomatic Infants Undergoing Heart Surgery.

Respiratory viral infections in infants undergoing congenital heart surgery lead to prolonged intubation time, hospital (HLOS) and cardiac intensive care unit length of stay (CICU LOS). The objective of this study was to evaluate the prevalence of respiratory viruses using molecular testing in otherwise healthy infants presenting for low complexity heart surgery, and to evaluate the impact of a positive viral screen and study questionnaire on post-surgical HLOS, CICU LOS, intubation time, respiratory complications, and oxygen therapy at home discharge. Sixty-nine infants (1 month to 1 year) undergoing cardiac surgery from November to May of the years 2012 to 2014 were prospectively enrolled, surveyed and tested. We compared the outcomes of positive molecular testing and positive study questionnaire to test negative subjects. We also evaluated the predictive value of study questionnaire in identification of viruses by molecular testing. Of the 69 enrolled infants, 58 had complete information available for analysis. 17 (30%) infants tested positive by molecular testing for respiratory pathogens. 38 (65%) had a "positive" questionnaire. Among the 20 viruses detected, Human Rhinovirus was the most common 12 (60%). Seven (12%) of the 58 patients developed respiratory symptoms following surgery prompting molecular testing. Four of these tested positive for a respiratory virus post-surgically. Neither positive molecular testing nor a positive questionnaire prior to surgery was associated with greater post-operative HLOS, CICU LOS, intubation time, respiratory complications, or use of oxygen at discharge compared to negative testing. The questionnaire poorly predicted positive molecular testing. Routine screening for respiratory viruses in asymptomatic infants may not be an effective strategy to predict infants at risk of post-operative complications.

Surveillance Testing and Preventive Care After Fontan Operation: A Multi-Institutional Survey.

More children with single ventricle heart disease are surviving after Fontan surgery. This circulation has pervasive effects on multiple organ systems and has unique modes of failure. Many centers have created multidisciplinary programs to care for these patients. Our aim was to survey such programs to better understand current approaches to care. We hypothesized that significant variability in surveillance testing strategy would be present. Eleven academic institutions with established Fontan care programs performing a combined estimated 300 Fontan surgeries per year, with a total population of 1500-2000 Fontan patients, were surveyed using a REDCap survey regarding surveillance testing and basic practice philosophies. Fontan care programs were structured both as consultative services (64%) and as the primary clinical team (9%). Electrocardiograms (73%) and echocardiograms (64%) were most commonly obtained annually. Serum studies, including complete blood count (73%), complete metabolic panel (73%), and Brain-type natriuretic peptide (54%), were most commonly obtained annually. Hepatic testing consisted of liver ultrasound in most centers, obtained biennially (45%) or > every 2 years (45%). Liver biopsy was not routinely recommended (54%). Neurodevelopmental outcomes were assessed at most institutions (54%), with a median frequency of every 3-4 years. There is considerable variability in the surveillance testing regimen and management strategy after a Fontan procedure at surveyed programs. There is an urgent need for surveillance guidelines to reduce variability, define quality metrics, streamline collaborative practice, and prospective research to better understand the complex adaptations of the body to Fontan physiology.

Design and rationale of the Fontan Udenafil Exercise Longitudinal (FUEL) trial.

The Fontan operation creates a circulation characterized by elevated central venous pressure and low cardiac output. Over time, these characteristics result in a predictable and persistent decline in exercise performance that is associated with an increase in morbidity and mortality. A medical therapy that targets the abnormalities of the Fontan circulation might, therefore, be associated with improved outcomes. Udenafil, a phosphodiesterase type 5 inhibitor, has undergone phase I/II testing in adolescents who have had the Fontan operation and has been shown to be safe and well tolerated in the short term. However, there are no data regarding the long-term efficacy of udenafil in this population. The Fontan Udenafil Exercise Longitudinal (FUEL) Trial is a randomized, double-blind, placebo-controlled phase III clinical trial being conducted by the Pediatric Heart Network in collaboration with Mezzion Pharma Co, Ltd. This trial is designed to test the hypothesis that treatment with udenafil will lead to an improvement in exercise capacity in adolescents who have undergone the Fontan operation. A safety extension trial, the FUEL Open-Label Extension Trial (FUEL OLE), offers the opportunity for all FUEL subjects to obtain open-label udenafil for an additional 12 months following completion of FUEL, and evaluates the long-term safety and tolerability of this medication. This manuscript describes the rationale and study design for FUEL and FUEL OLE. Together, these trials provide an opportunity to better understand the role of medical management in the care of those who have undergone the Fontan operation.

Prevalence of Coronary Artery Disease Risk Factors and Metabolic Syndrome in Children with Heart Disease.

Children with acquired and congenital heart disease (CHD) are increasingly surviving to adulthood. Our aim was to determine the prevalence of coronary artery disease (CAD) risk factors in children at known risk for early CAD or with severe CHD. We recruited children (8-19 years) at risk for early CAD-Kawasaki disease (KD, N = 36) and coarctation (69) or severe CHD: > 1 cardiopulmonary bypass surgery (60), single ventricle (15), prosthetic valves (13). Anthropometric measurements, blood pressure, and fasting lipid data were compared with summaries from National Health and Nutrition Examination Survey (NHANES) publications (1999-2012). Relative risk (RR) ratios were calculated based on age classification and pooled to obtain overall RR. Of 174 subjects, 106 were male (61%) and 138 (79%) had CHD. Compared to NHANES data, hypertension and low HDL were higher in the study cohort [RR 11.7 (CI 6.34-21.6), p < 0.001; and 1.79 (CI 1.36-2.35). p < 0.001] and obesity and elevated total cholesterol were lower [RR 0.59 (CI 0.37-0.96), p = 0.03; and 0.42 (CI 0.19-0.95), p = 0.04]. Elevated non-HDL was similar between groups. Age category had similar RR for all CAD risk factors. Eight subjects had metabolic syndrome. Risk factors were similar between KD versus CHD subgroups. Both coarctation and non-coarctation subjects had increased RR for hypertension. Hypertension is the most common risk factor for children at risk of early CAD and severe CHD. Metabolic syndrome is rare. These patients should be screened and treated for hypertension and current recommendations for universal lipid screening are adequate for follow-up.

Digoxin Use in Infants with Single Ventricle Physiology: Secondary Analysis of the Pediatric Heart Network Infant Single Ventricle Trial Public Use Dataset.

Digoxin has been associated with reduced interstage mortality after Norwood procedure. We sought to determine its association with survival and change in weight-for-age Z-score (WAZ) before the superior cavopulmonary connection (SCPC) surgery and at 14 months in a heterogeneous group of single ventricle infants. We performed a post-hoc analysis of the Pediatric Heart Network Infant Single Ventricle public use dataset to determine associations between digoxin and survival, transplant-free survival, and change in WAZ pre-SCPC and at 14 months. Sub-analyses of survival and transplant-free survival were performed for subjects who underwent Damus-Kaye-Stansel (DKS)/Norwood. Propensity score weighting was used in Cox hazard-proportion models. Of 229 subjects, 82 (36%) received digoxin and 147 (64%) received no digoxin. Pre-SCPC and 14-month survival and transplant-free survival were not significantly different between the digoxin and no digoxin groups for the main cohort and DKS/Norwood sub-group. However, in DKS/Norwood subjects there was a trend towards improved interstage transplant-free survival in the digoxin group (95.7 vs. 89.6%, p = 0.08). Digoxin was associated with a greater decrease in WAZ from birth to pre-SCPC (- 1.96 ± 0.19 vs. - 1.31 ± 0.18, p < 0.001) and birth to 14 months (- 0.64 ± 0.15 vs. - 0.19 ± 0.15, p = 0.03). Digoxin was not associated with improved survival during the interstage or at 14 months in a mixed single ventricle cohort, but there was a trend towards improved interstage transplant-free survival in post-Norwood infants. As digoxin was associated with poorer weight gain, further research is needed to identify the risks/benefits for anatomic subtypes of infants with single ventricles.

Predictors of Rapid Aortic Root Dilation and Referral for Aortic Surgery in Marfan Syndrome.

Few data exist regarding predictors of rapid aortic root dilation and referral for aortic surgery in Marfan syndrome (MFS). To identify independent predictors of the rate of aortic root (AoR) dilation and referral for aortic surgery, we investigated the data from the Pediatric Heart Network randomized trial of atenolol versus losartan in young patients with MFS. Data were analyzed from the echocardiograms at 0, 12, 24, and 36 months read in the core laboratory of 608 trial subjects, aged 6 months to 25 years, who met original Ghent criteria and had an AoR z-score (AoRz) > 3. Repeated measures linear and logistic regressions were used to determine multivariable predictors of AoR dilation. Receiver operator characteristic curves were used to determine cut-points in AoR dilation predicting referral for aortic surgery. Multivariable analysis showed rapid AoR dilation as defined by change in AoRz/year > 90th percentile was associated with older age, higher sinotubular junction z-score, and atenolol use (R2 = 0.01) or by change in AoR diameter (AoRd)/year > 90th percentile with higher sinotubular junction z-score and non-white race (R2 = 0.02). Referral for aortic root surgery was associated with higher AoRd, higher ascending aorta z-score, and higher sinotubular junction diameter:ascending aorta diameter ratio (R2 = 0.17). Change in AoRz of 0.72 SD units/year had 42% sensitivity and 92% specificity and change in AoRd of 0.34 cm/year had 38% sensitivity and 95% specificity for predicting referral for aortic surgery. In this cohort of young patients with MFS, no new robust predictors of rapid AoR dilation or referral for aortic root surgery were identified. Further investigation may determine whether generalized proximal aortic dilation and effacement of the sinotubular junction will allow for better risk stratification. Rate of AoR dilation cut-points had high specificity, but low sensitivity for predicting referral for aortic surgery, limiting their clinical use. Clinical Trial Number ClinicalTrials.gov number, NCT00429364.

Outcomes After Pediatric Out-of-Hospital Cardiopulmonary Interventions.

OBJECTIVE: The aim of the study was to evaluate outcomes after pediatric out-of-hospital cardiopulmonary interventions (CPIs) by emergency medical services (EMS). METHODS: Children (age, ≤18 years) who received CPI by EMS from 2001 to 2008 were identified from the Utah Department of Health. Cardiopulmonary intervention was defined as oxygenation, ventilation or CPR, and transport to a hospital by EMS. Univariate and multivariable regression analyses evaluated associations between potential predictors and outcomes (death and new neurologic dysfunction). RESULTS: A total of 464 patients (58% male) received EMS attention. For the 71% patients (327) who were alive on EMS arrival, 63% (205) received CPI without CPR. Of note, 6% (12) of these patients died after arrival to the hospital and new neurologic dysfunction was diagnosed in 6% (13). Among the 12 patients who died, 50% (6) were younger than 1 year.On multivariable regression analysis, factors associated with increased risk of death before and in-hospital are the following: age younger than 1 year (odds ratio [OR], 0.26; 95% confidence interval [CI], 0.17-0.39), shorter EMS transport time (OR, 0.94; 95% CI, 0.89-0.99), and longer EMS dispatch time (OR, 1.23; 95% CI, 1.08-1.40). Factors associated with increased risk of new neurologic dysfunction are the following: lack of pulse (OR, 0.14; 95% CI, 0.04-0.53), requiring CPR (OR, 6.15; 95% CI, 1.48-25.6), and CPR duration (OR, 1.20; 95% CI, 1.05-1.37). CONCLUSIONS: Age younger than 1 year, shorter transport time, and longer dispatch time were associated with increased risk of death. Being pulseless upon discovery and receiving CPR were associated with new neurologic dysfunction. Maximizing EMS transport interventions for patients younger than 1 year requiring CPI may improve patient outcomes.

Risk stratification in pediatric hypertrophic cardiomyopathy: Insights for bridging the evidence gap?

Identification of children with hypertrophic cardiomyopathy (HCM) who are at high risk for sudden cardiac death (SCD) remains challenging. Although a large number of risk factors have been implicated in HCM associated SCD, evidence for individual risk factors are not robust. Current risk prediction models are extrapolated from adult HCM and have low positive predictive value when applied to the pediatric HCM population. Clinical factors that are strongly associated with SCD in children with HCM are limited to previous adverse cardiac event, prior syncope and extreme left ventricular hypertrophy; there are variable conclusions regarding the utility of other conventional risk factors. Additionally, while implantable cardioverter defibrillators (ICDs) are effective in aborting malignant arrhythmias, ICD complication rates are higher in children than in adults. Although echocardiography derived parameters like left atrial volume, diastolic function indices, severity of left ventricular outflow tract obstruction and abnormalities in deformation imaging (strain and strain rate) have been associated with SCD risk in childhood HCM, these echocardiographic predictors have low specificity and sensitivity. More recently, cardiac magnetic resonance (CMR) imaging derived perfusion and viability (delayed gadolinium enhancement) abnormalities have been associated with SCD in childhood HCM and warrant further investigation. Given that myocyte disarray and fibrosis are prominent histological features of HCM, novel imaging modalities that allow for improved tissue characterization may provide additional insight into HCM phenotypes that are at higher risk for SCD. T1 mapping, cardiac diffusion tensor imaging (cDTI), and assessment of a phosphocreatine/adenosine triphosphate (PCr/ATP) ratio by 31P magnetic resonance spectroscopy (31P-MRS) are future avenues of myocardial imaging that may provide additional prognostic benefit when used in conjunction with traditional assessments. Further investigations of disease pathogenesis, genotype-phenotype correlations, genetic modifiers and circulating biomarkers specific to children with HCM hold promise for a more effective and refined risk stratification model in pediatric HCM.

Results of a phase I/II multi-center investigation of udenafil in adolescents after fontan palliation.

BACKGROUND: The Fontan operation results in a circulation that is dependent on low pulmonary vascular resistance to maintain an adequate cardiac output. Medical therapies that lower pulmonary vascular resistance may augment cardiac output and improve long-term outcomes. OBJECTIVES: This phase I/II clinical trial conducted by the Pediatric Heart Network was designed to evaluate short-term safety, pharmacokinetics (PK), and preliminary efficacy of udenafil in adolescents following Fontan. METHODS: A 5-day dose-escalation trial was conducted in five study cohorts of six subjects each (37.5, 87.5, and 125 mg daily, 37.5 and 87.5 mg by mouth twice daily). A control cohort with 6 subjects underwent exercise testing only. Adverse events (AEs) were recorded, PK samples were collected on study days six through eight, and clinical testing was performed at baseline and day five. RESULTS: The trial enrolled 36 subjects; mean age 15.8 years (58% male). There were no significant differences in subject characteristics between cohorts. No drug-related serious AEs were reported during the study period; 24 subjects had AEs possibly or probably related to study drug. Headache was the most common AE, occurring in 20 of 30 subjects. The 87.5 mg bid cohort was well tolerated, achieved the highest maximal concentration (506 ng/mL) and the highest average concentration over the dosing interval (279 ng/mL), and was associated with a suggestion of improvement in myocardial performance. Exercise performance did not improve in any of the dosing cohorts. CONCLUSIONS: Udenafil was well-tolerated at all dosing levels. The 87.5 mg bid cohort achieved the highest plasma drug level and was associated with a suggestion of improvement in myocardial performance. These data suggest that the 87.5 mg bid regimen may be the most appropriate for a Phase III clinical trial.

Acute and midterm results following perventricular device closure of muscular ventricular septal defects: A multicenter PICES investigation.

OBJECTIVES: To describe acute and mid-term results of hybrid perventricular device closure of muscular ventricular septal defects (mVSDs). BACKGROUND: Perventricular device closure of mVSDs can mitigate technical limitations of percutaneous closure and need for cardiopulmonary bypass or ventriculotomy with a surgical approach. METHODS: This is a multicenter retrospective cohort study of patients undergoing hybrid perventricular mVSD device closure from 1/2004 to 1/2014. Procedural details, adverse events, outcomes, and follow-up data were collected. Patients were divided into two groups: (1) simple (mVSD closure alone) and (2) complex (mVSD closure with concomitant cardiac surgery). RESULTS: Forty-seven patients (60% female) underwent perventricular mVSD device closure at a median age of 5.2 months (IQR 1.8-8.9) and weight of 5.1 kg (IQR 4.0-6.9). Procedural success was 91% [100% (n = 22) simple and 84% (n = 21/25) complex]. Adverse events occurred in 19% (9/47) [9% (2/22) simple and 28% (7/25) complex]. Hospital length of stay (LOS) was shorter in the simple vs. complex group (4 vs. 14 days, P < 0.01). At mid-term follow-up of 19.2 months (IQR 2.3-43) 90% of pts had complete mVSD closure; none developed late heart block, increased atrioventricular (AV) valve insufficiency or ventricular dysfunction. CONCLUSIONS: Perventricular device closure of simple mVSD was associated with a high rate of procedural success, few adverse events, and short hospital LOS. Procedural adverse events were associated with the presence of concomitant complex surgery. Residual mVSD, AV valve insufficiency, or ventricular dysfunction were uncommon at mid-term follow-up. © 2017 Wiley Periodicals, Inc.

Alteration of Cardiac Deformation in Acute Rejection in Pediatric Heart Transplant Recipients.

The objective of this study is to assess changes in cardiac deformation during acute cellular- and antibody-mediated rejection in pediatric HT recipients. Pediatric HT recipients aged ≤18 years with at least one episode of biopsy-diagnosed rejection from 2006 to 2013 were included. Left ventricular systolic S (SS) and SR (SSr) data were acquired using 2D speckle tracking on echocardiograms obtained within 12 h of right ventricular endomyocardial biopsy. A mixed effect model was used to compare cardiac deformation during CR (Grade ≥ 1R), AMR (pAMR ≥ 2), and mixed rejection (CR and AMR positive) versus no rejection (Grade 0R and pAMR 0 or 1). A total of 20 subjects (10 males, 50%) with 71 rejection events (CR 35, 49%; AMR 21, 30% and mixed 15, 21%) met inclusion criteria. The median time from HT to first biopsy used for analysis was 5 months (IQR 0.25-192 months). Average LV longitudinal SS and SSr were reduced significantly during rejection (SS: -17.2 ± 3.4% vs. -10.7 ± 4.5%, p < 0.001 and SSr: -1.2 ± 0.2 s- 1 vs. -0.9 ± 0.3 s- 1; p < 0.001) and in all rejection types. Average LV short-axis radial SS was reduced only in CR compared to no rejection (p = 0.04), while average LV circumferential SS and SSr were reduced significantly in AMR compared to CR (SS: 18.9 ± 4.2% vs. 20.8 ± 8.8%, p = 0.03 and SSr: 1.35 ± 0.8 s- 1 vs. 1.54 ± 0.9 s- 1; p = 0.03). In pediatric HT recipients, LV longitudinal SS and SSr were reduced in all rejection types, while LV radial SS was reduced only in CR. LV circumferential SS and SSr further differentiated between CR and AMR with a significant reduction seen in AMR as compared to CR. This novel finding suggests mechanistic differences between AMR- and CR-induced myocardial injury which may be useful in non-invasively predicting the type of rejection in pediatric HT recipients.

A multi-institutional study of factors affecting resource utilisation following the Fontan operation.

The few studies evaluating data on resource utilisation following the Fontan operation specifically are outdated. We sought to evaluate resource utilisation and factors associated with increased resource use after the Fontan operation in a contemporary, large, multi-institutional cohort. This retrospective cohort study of children who had the Fontan between January, 2004 and June, 2013 used the Pediatric Health Information Systems Database. Generalised linear regression analyses evaluated factors associated with resource use. Of 2187 Fontan patients included in the study, 62% were males. The median age at Fontan was 3.2 years (inter-quartile range (IQR): 2.6-3.8). The median length of stay following the Fontan was 9 days (IQR: 7-14). The median costs and charges in 2012 dollars for the Fontan operation were $93,900 (IQR: $67,800-$136,100) and $156,000 (IQR: $112,080-$225,607), respectively. Postoperative Fontan mortality (30 days) was 1% (n=21). Factors associated with increased resource utilisation included baseline and demographic factors such as region, race, and renal anomaly, factors at the bidirectional Glenn such as seizures, valvuloplasty, and surgical volume, number of admissions between the bidirectional Glenn and the Fontan, and factors at the Fontan such as surgical volume and age at Fontan. The most strongly associated factors for both increased Fontan length of stay and increased Fontan charges were number of bidirectional Glenn to Fontan admissions (p<0.001) and Fontan surgical volume per year (p<0.001). As patient characteristics and healthcare-related delivery variables accounted for most of the factors predicting increased resource utilisation, changes should target healthcare delivery factors to reduce costs in this resource-intensive population.

Novel Cardiac Magnetic Resonance Feature Tracking (CMR-FT) Analysis for Detection of Myocardial Fibrosis in Pediatric Hypertrophic Cardiomyopathy.

Myocardial fibrosis is a risk factor for sudden cardiac death in hypertrophic cardiomyopathy (HCM) and is conventionally identified by cardiac magnetic resonance imaging (CMR) using late gadolinium enhancement (LGE). This study evaluates utility of a novel 16-segment CMR feature tracking (CMR-FT) technique for measuring left ventricular (LV) strain (S) and strain rate (SR) on non-contrast cine images to detect myocardial fibrosis in pediatric HCM. We hypothesized that CMR-FT-derived S and SR will accurately differentiate HCM patients with and without myocardial fibrosis. Consecutive children with HCM who underwent CMR with LGE at our institution from 2006 to 2014 were included. Global and regional longitudinal, radial and circumferential S and SR of the LV in 2D and 3D were obtained using a CMR-FT software. Comparisons were made between HCM patients with (+LGE) and without (-LGE) delayed enhancement. Of the 29 HCM patients (mean age 13.5 ± 6.1 years; 52 % males), 11 (40 %) patients (mean age 17.5 ± 8.4 years) had +LGE. Global longitudinal, circumferential and radial S and SR were lower in +LGE compared to -LGE patients, in both 2D and 3D. Regional analysis revealed lower segmental S and SR in the septum with fibrosis compared to free wall without fibrosis. A global longitudinal S of ≤ -12.8 had 91 % sensitivity and 89 % specificity for detection of LGE. In pediatric HCM patients with myocardial fibrosis, global LV longitudinal, circumferential and radial S and SR were reduced, specifically in areas of fibrosis. A global longitudinal S of ≤ -12.8 detected patients with fibrosis with high degree of accuracy. This novel CMR-FT technique may be useful to identify myocardial fibrosis and risk-stratify pediatric HCM without use of contrast agents.