Design and implementation of multicenter pediatric and congenital studies with cardiovascular magnetic resonance: Big data in smaller bodies.

Cardiovascular magnetic resonance (CMR) has become the reference standard for quantitative and qualitative assessment of ventricular function, blood flow, and myocardial tissue characterization. There is a preponderance of large CMR studies and registries in adults; However, similarly powered studies are lacking for the pediatric and congenital heart disease (PCHD) population. To date, most CMR studies in children are limited to small single or multicenter studies, thereby limiting the conclusions that can be drawn. Within the PCHD CMR community, a collaborative effort has been successfully employed to recognize knowledge gaps with the aim to embolden the development and initiation of high-quality, large-scale multicenter research. In this publication, we highlight the underlying challenges and provide a practical guide toward the development of larger, multicenter initiatives focusing on PCHD populations, which can serve as a model for future multicenter efforts.

Predictors of post-operative left atrioventricular valve regurgitation in pediatric patients with complete atrioventricular canal defects.

BACKGROUND: In infants with complete atrioventricular canal (CAVC) defects, post-operative left atrioventricular valve regurgitation (LAVVR) is a known major cause of morbidity and mortality and a common indication for re-operation. However, there is scarce data to identify risk factors for poor outcomes. Our study aims to find echocardiographic characteristics that predict post-operative LAVVR at discharge and 1-year follow-up. METHODS: Retrospective cohort study of patients with initial CAVC repair at our hospital who were followed for 1 year between 2013 and 2022. Patients with major co-morbid conditions were excluded. Serial echocardiograms were reviewed. Anatomic details, quantitative and qualitative measure of LAVVR including the number of regurgitant jets, regurgitant jet length and vena contracta width, and ventricular function were collected. The time points measured include pre-operative transthoracic echocardiogram (TTE), post-operative transesophageal echocardiogram (PO-TEE), routine protocol based post-operative day 1 (POD1) TTE, discharge TTE and 1-year post-operative (1yPO) TTE. Paired t-tests, chi-square analysis, and linear regression analysis were performed comparing measured variables to LAVVR outcomes. RESULTS: Fifty-two patients were included; 92% had Trisomy 21. The majority were classified as Rastelli A (71%), others Rastelli C (29%). Only two patients had moderate or greater LAVVR pre-operatively. The mean age at repair was 125 ± 44 days. Pre-operative LAVVR was the only significant predictor of LAVVR severity at 1 year after backward stepwise regression. Of those with < moderate LAVVR on PO-TEE, 20% had worsening to ≥ moderate at discharge, but only 9% remained that way at 1 year. Of those with ≥ moderate LAVVR on PO-TEE, 40% improved to < moderate by 1 year. Two patients who worsened at 1 year, both secondary to likely cleft suture dehiscence. Only one patient required reoperation in the immediate post-operative period secondary to severe LAVVR due to suture dehiscence. Routine protocol-based POD1 echo did not have any association with altered outcomes. CONCLUSION: Pre-operative LAVVR was the only significant predictor of LAVVR severity at 1 year. A significant percentage (40%) of patient with ≥ moderate LAVVR on PO-TEE improved to < moderate by 1 year. Furthermore, routine protocol-based POD1 echo did not have any association with altered outcomes.

Persistent Cardiac Magnetic Resonance Imaging Findings in a Cohort of Adolescents with Post-Coronavirus Disease 2019 mRNA Vaccine Myopericarditis.

We describe the evolution of cardiac magnetic resonance imaging findings in 16 patients, aged 12-17 years, with myopericarditis after the second dose of the Pfizer mRNA coronavirus disease 2019 vaccine. Although all patients showed rapid clinical improvement, many had persistent cardiac magnetic resonance imaging findings at 3- to 8-month follow-up.

Survey of centers performing cardiovascular magnetic resonance in pediatric and congenital heart disease: a report of the Society for Cardiovascular Magnetic Resonance.

BACKGROUND: There are few data on practice patterns and trends for cardiovascular magnetic resonance (CMR) in pediatric and congenital heart disease. The Society for Cardiovascular Magnetic Resonance (SCMR) sought to address this deficiency by performing an international survey of CMR centers. METHODS: Surveys consisting of 31 (2014) and 33 (2018) items were designed to collect data on the use of CMR for the evaluation of pediatric and congenital heart disease patients. They were sent to all SCMR members in 2014 and 2018. One response per center was collected. RESULTS: There were 93 centers that responded in 2014 and 83 in 2018. The results that follow show data from 2014 and 2018 separated by a dash. The median annual number of pediatric/congenital CMR cases per center was 183-209. The median number of scanners for CMR was 2-2 (range, 1-8) with 58-63% using only 1.5T scanners and 4-4% using only 3T scanners. The mean number of attending/staff reading CMRs was 3.7-2.6; among them, 52-61% were pediatric or adult cardiologists and 47-38% were pediatric or adult radiologists. The median annual case volume per attending was 54-86. The median number of technologists per center doing CMRs was 4-5. The median scanner time allocated for a non-sedated examination was 75-75 min (range, 45-120). Among the 21 centers responding to both surveys, the mean annual case volume increased from 320 in 2014 to 445 in 2018; 17 (81%) of the centers had an increase in annual case volume. For this subgroup, the median attending/staff per center was 4 in both 2014 and 2018. The median scanner time allotted per study was unchanged at 90 min. The mean time for an attending/staff physician to perform a typical CMR examination including reporting was 143-141 min. CONCLUSION: These survey data provide a novel comprehensive view of CMR practice in pediatric and congenital heart disease. This information is useful for internal benchmarking, resource allocation, addressing practice variation, quality improvement initiatives, and identifying unmet needs.

Myopericarditis After the Pfizer Messenger Ribonucleic Acid Coronavirus Disease Vaccine in Adolescents.

Reports have emerged of myocarditis and pericarditis predominantly after the second dose of the coronavirus disease messenger ribonucleic acid vaccine. We describe 13 patients aged 12-17 years who presented with chest pain within 1 week after their second dose of the Pfizer vaccine and were found to have elevated serum troponin levels and evidence of myopericarditis.

Is biventricular vascular coupling a better indicator of ventriculo-ventricular interaction in congenital heart disease?

BACKGROUND: Ventriculo-ventricular interactions are known to exist, though not well quantified. We hypothesised that the ventricular-vascular coupling ratio assessed by cardiovascular MRI would provide insight into this relationship. We also sought to compare MRI-derived ventricular-vascular coupling ratio to echocardiography and patient outcomes. METHODS: Children with cardiac disease and biventricular physiology were included. Sanz's and Bullet methods were used to calculate ventricular-vascular coupling ratio by MRI and echocardiography, respectively. Subgroup analysis was performed for right and left heart diseases. Univariate and multivariate regressions were performed to determine associations with outcomes. RESULTS: A total of 55 patients (age 14.3 ± 2.5 years) were included. Biventricular ventricular-vascular coupling ratio by MRI correlated with each other (r = 0.41; p = 0.003), with respect to ventricle's ejection fraction (r = -0.76 to -0.88; p < 0.001) and other ventricle's ejection fraction (r = -0.42 to -0.47; p < 0.01). However, biventricular ejection fraction had only weak correlation with each other (r = 0.31; p = 0.02). Echo underestimated ventricular-vascular coupling ratio for the left ventricle (p < 0.001) with modest correlation to MRI-derived ventricular-vascular coupling ratio (r = 0.43; p = 0.002). There seems to be a weak correlation between uncoupled right ventricular-vascular coupling ratio with the need for intervention and performance on exercise testing (r = 0.33; p = 0.02). CONCLUSION: MRI-derived biventricular ventricular-vascular coupling ratio provides a better estimate of ventriculo-ventricular interaction in children and adolescents with CHD. These associations are stronger than traditional parameters and applicable to right and left heart conditions.

Tripartite Assessment of Right Ventricular Systolic Function in Persistent Pulmonary Hypertension of the Newborn.

Non-invasive evaluation of right ventricular (RV) systolic function in neonates with pulmonary hypertension (PH) with traditional metrics including RV fractional area change (FAC) and tricuspid annular systolic plane excursion (TAPSE) has improved outcomes. Apical three-chamber (3C) RV-FAC, a novel tripartite assessment of the RV, has recently been described in healthy infants. We assess the utility of 3C RV-FAC and biplane RV-FAC in delayed transitioning and neonatal PH. Echocardiograms for 22 normal infants and 22 infants with PH were retrospectively analyzed for RV systolic function indices including four chamber (4C), 3C, and biplane RV-FAC, TAPSE, Tei index, and RV systolic excursion velocity (S'). 4C, 3C, and biplane RV-FAC correlated with PH severity and was decreased in neonates with PH compared to normal neonates (biplane RV-FAC 31.7 ± 13.4% vs. 41 .9 ± 4.7%, p = 0.002). TAPSE was significantly decreased in neonates with PH, but did not correlate with PH severity. Other RV systolic function metrics were not significantly different between normal neonates and neonates with PH. 3C RV-FAC and biplane RV-FAC are lower in neonates with PH. 3C and biplane RV-FAC may allow for improved assessment of global RV systolic dysfunction in newborns with delayed transitioning or PH compared to the commonly used regional methods.

An unusual case of concordant ventriculoarterial connections, subpulmonary infundibulum, and parallel arterial trunks: a diagnostic challenge.

We present an unusual case of concordant ventriculoarterial connections, subpulmonary infundibulum, and parallel arterial trunks. This case was complicated by extreme pulmonary artery tortuosity and low arching aorta causing severe tracheal compression. We discuss the difficulty in prenatal diagnosis, necessity for advanced imaging postnatally, and associated airway complications.

Diagnostic role of strain imaging in atypical myocarditis by echocardiography and cardiac MRI.

BACKGROUND: The diagnosis of myocarditis presenting as isolated acute chest pain with elevated troponins but normal systolic function is challenging with significant drawbacks even for the gold-standard endomyocardial biopsy. OBJECTIVE: This study aimed to evaluate the diagnostic role of strain imaging by echocardiography and cardiac MRI in these patients. MATERIALS AND METHODS: This was a retrospective review of children with cardiac MRI for acute chest pain with elevated troponins compared to normal controls. Echocardiographic fractional shortening, ejection fraction, speckle-tracking-derived peak longitudinal, radial, and circumferential strain were compared to cardiac MRI ejection fraction, T2 imaging, late gadolinium enhancement, speckle-tracking-derived peak longitudinal strain, radial strain, and circumferential strain. RESULTS: Group 1 included 10 subjects diagnosed with myocarditis, 9 (90%) males with a median age of 15.5 years (range: 14-17 years) compared with 10 age-matched controls in group 2. All subjects in group 1 had late gadolinium enhancement consistent with myocarditis and troponin ranged from 2.5 to >30 ng/ml. Electrocardiogram changes included ST segment elevation in 6 and abnormal Q waves in 1. Qualitative echocardiographic function was normal in both groups and mean fractional shortening was similar (35±6% in group 1 vs. 34±4% in group 2, P=0.70). Left ventricle ejection fraction by cardiac MRI, however, was lower in group 1 (52±9%) compared to group 2 at (59±4%) (P=0.03). Cardiac MRI derived strain was lower in group 1 vs. group 2 for speckle-tracking-derived peak longitudinal strain (-12.8±2.8% vs. -17.1±1.5%, P=0.001), circumferential strain (-12.3±3.8% vs. -15.8±1.2%, P=0.020) and radial strain (13.6±3.7% vs. 17.2±3.2%, P=0.040). Echocardiography derived strain was also lower in group 1 vs. group 2 for speckle-tracking-derived peak longitudinal strain (-15.6±3.9% vs. -20.8±2.2%, P<0.002), circumferential strain (-16±3% vs. -19.8±1.9%, P<0.003) and radial strain (17.3±6.1% vs. 24.8±6.3%, P=0.010). CONCLUSION: In previously asymptomatic children, myocarditis can present with symptoms of acute chest pain suspicious for coronary ischemia. Cardiac MRI and echocardiographic strain imaging are noninvasive, radiation-free tests of immense diagnostic utility in these situations. Long-term studies are needed to assess prognostic significance of these findings.

Comparison of two-dimensional and three-dimensional echocardiographic strain in children with CHD.

BACKGROUND: In CHD, three-dimensional strain analysis may overcome limitations of Doppler and two-dimensional strain of the left ventricle. The aims of this study were to evaluate feasibility and reproducibility of three-dimensional longitudinal, circumferential, and radial systolic strain by three-dimensional speckle-tracking echocardiography compared with two-dimensional echocardiography. METHODS: Patients with CHD, biventricular circulation with a systemic left ventricle, and who had two- and three-dimensional imaging performed on the same day from 2010 to 2014 were included. Quantitative two- and three-dimensional strain analyses were performed (two-dimensional cardiac performance analysis version 1.2 and four-dimensional left ventricular analysis version 3.1). Intra- and inter-observer variabilities were calculated on 25 studies. RESULTS: A total of 30 patients, including 19 (61%) males, with a median age of 3.6 years (0.1-22 years) were included. The mean fractional shortening was 34.6±5.3%, and the mean ejection fraction was 62.0±6.4%. Measurement of two- and three-dimensional strain was feasible in >95% of segments. Good correlation was observed between longitudinal and circumferential strain (r=0.92, p⩽0.001 and r=0.87, p⩽0.001), but not radial strain (r=0.29, p=0.2). Intra- and inter-observer agreements were better for three-dimensional compared with two-dimensional strain, and better for both two- and three-dimensional longitudinal and circumferential strains compared with radial strain. CONCLUSION: Left ventricular three-dimensional strain analysis is feasible in children with CHD. The reproducibility of longitudinal and circumferential strain by three-dimensional analyses is better. Further longitudinal studies are warranted for the potential clinical application of this new technology.

Right ventricular global longitudinal strain in repaired tetralogy of Fallot.

BACKGROUND: Echocardiogram has limitations in effectively assessing right ventricular (RV) function in children post tetralogy of Fallot (TOF) repair. We evaluated the utility of speckle tracking echocardiography (STE)-based RV global longitudinal strain (GLS) for the assessment of RV systolic function. METHODS: All patients with repaired TOF who had both echocardiograms and cardiac MRI (CMR) within a 6-month interval were included. RV volumes and ejection fraction (EF) were obtained by CMRs. Traditional echocardiographic function parameters and RV GLS were compared to CMR-derived RV EF. Subjects were divided into two groups based on CMR RV EF (group I: RV EF ≥45%; and group II: RV EF <45%). RESULTS: A total of 57 subjects were included. Mean age was 13.0±3.6 years and 58% were males. Group I had 39 subjects and group II had 18. Only six of the 18 patients (33%) in group II were identified as having at least mild RV dysfunction by echocardiogram. The mean RV GLS was significantly abnormal in group II (-15.3±3.8%) compared to group I (-20.9±3.3%; P<.001). By ROC analysis, an RV GLS cutoff value of -18% had 78% sensitivity and 77% specificity in identifying RV EF <45% (area under curve .87, P<.001). Intra- and inter-observer reproducibility of RV GLS were good. CONCLUSION: RV GLS is a simple and effective tool for the assessment of RV systolic function in patients post TOF repair. This technique would help further refine patient selection for timing of CMR and management.

Comparison of left ventricular function assessment between echocardiography and MRI in Duchenne muscular dystrophy.

BACKGROUND: Cardiomyopathy in Duchenne muscular dystrophy (DMD) is associated with death in approximately 40% of patients. Echocardiography is routinely used to assess left ventricular (LV) function; however, it has limitations in these patients. OBJECTIVE: We compared echocardiographic measures of cardiac function assessment to cardiac MRI. MATERIALS AND METHODS: We included children and young adults with DMD who had MRI performed between January 2010 and July 2015. We measured echocardiographic and MRI parameters of function assessment, including strain. Presence of late gadolinium enhancement (LGE) was assessed by MRI. Subjects were divided into two groups based on MRI left ventricular ejection fraction (LVEF): group I, LVEF ≥55% and group II, LVEF <55%. RESULTS: We included 41 studies in 33 subjects, with 25 in group I and 16 in group II. Mean age of subjects was 13.6 ± 2.8 years and mean duration between echocardiogram and MRI was 7.6 ± 4.1 months. Only 8 of 16 (50%) patients in group II had diminished function on echocardiogram. Echocardiographic images were suboptimal in 16 subjects (39%). Overall, echocardiographic parameters had weak correlation with MRI-derived ejection fraction percentage. MRI-derived myocardial strain assessment has better correlation with MRI ejection fraction as compared to echocardiography-derived strain parameters. CONCLUSION: Echocardiography-based ventricular functional assessment has weak correlation with MRI parameters in children and young adults with Duchenne muscular dystrophy. While this correlation improves in the subset of subjects with adequate echocardiographic image quality, it remains modest and potentially suboptimal for clinical management. Accordingly, we conclude that MRI should be performed routinely and early in children with DMD, not only for LGE imaging but also for functional assessment.

Right Ventricular Apical Flattening as an Echocardiographic Screening Tool for Right Ventricular Enlargement.

Right ventricular dilation is a common complication after tetralogy of Fallot (TOF) repair. Traditional echocardiographic assessments are imprecise due to the RV's location and complex geometry. We propose a novel echocardiographic measurement: RV apical flattening (RVAF) as a screening tool to help identify subjects with severe RV dilation. Patients with repaired TOF who had both echocardiograms and CMR's within 6-month interval at our institution were included in the study. The RVAF was measured in the four-chamber echocardiographic view as the minor length of RV cavity at the level of RV apical endocardium. Subjects were divided into two groups (group I: RVEDVi ≥ 150 ml/m(2) and group II; RVEDVi < 150 ml/m(2)). Echocardiogram and CMR data were compared between groups. A total of 75 subjects were included in the study. Mean age was 12.8 ± 3.6 years. Group I had 36 subjects, and group II had 39 subjects. The mean RVAF was significantly higher in group I (2.7 ± 0.5 cm) compared with group II (1.7 ± 0.4 cm; p < 0.001). There was significant correlation between RVAF and RVEDVi (r = 0.81; p < 0.001). By ROC analysis, an RVAF cutoff value of 2.0 cm had 94 % sensitivity and 77 % specificity in identifying severe RV dilation (area under the curve 0.95). RVAF is a simple and effective echocardiographic screening tool to help identify severe RV dilation. In conjunction with other 2D echocardiographic parameters, this technique would help further refine echocardiography-guided patient selection for timing of CMR and pulmonary valve replacement.

Risk of congenital heart defects in the offspring of smoking mothers: a population-based study.

OBJECTIVES: To conduct a population-based study examining the occurrence of congenital heart defects (CHDs) in relation to maternal smoking during the first trimester of pregnancy. STUDY DESIGN: This retrospective case-control study used Washington State birth certificates from 1989 to 2011 and linked hospital discharge International Classification of Diseases, 9th revision, codes to identify singleton nonsyndromic CHD cases and determine maternal prenatal smoking status. We calculated ORs from multivariate logistic regression models to compare maternal first-trimester smoking status (any and daily number of cigarettes) among 14,128 cases, both overall and by phenotype, and 60,938 randomly selected controls frequency matched on birth year. RESULTS: Offspring of mothers reporting cigarette use in the first trimester of pregnancy were more likely to be born with a CHD (aOR 1.16 [1.08-1.24]) independent of demographic characteristics and other prenatal risk factors for CHDs. Maternal smoking was most strongly associated with pulmonary valve anomalies (aOR 1.48 [95% CI: 1.15-1.90]), pulmonary artery anomalies (aOR 1.71 [1.40-2.09]), and isolated atrial septal defects (aOR 1.22 [1.08-1.38]). The association between maternal smoking and CHDs was stronger with increasing number of daily cigarettes and among older (35+ years) mothers compared with younger mothers. CONCLUSIONS: We provide evidence that maternal smoking during pregnancy is a risk factor for select CHD phenotypes. Maternal smoking may account for 1.4% of all CHDs. New findings include a strong dose-dependence of the association and augmented risk in older mothers.

Progression of right ventricular dilation in repaired tetralogy of Fallot.

PURPOSE: To evaluate factors associated with rapid rate of progression (ROP) of right ventricular (RV) dilation by cardiac MRI in repaired tetralogy of Fallot (TOF) patients. MATERIALS AND METHODS: All patients with repaired TOF with two MRIs were included. RV volumes and function were assessed by MRIs performed on a GE 1.5 Tesla (T) platform. The ROP of RV dilation was calculated as the difference between the last and first RV indexed end-diastolic volumes (iEDV) divided by the time difference. Subjects were divided into two groups: Group I-rapid ROP (top quartile of ROP) and Group II-slower ROP (lower three quartiles). RESULTS: A total of 61 subjects were included. Mean age was 18.0 ± 9.7 years and duration between MRIs 3.4 ± 2.1 years. Median ROP for RV iEDV was 2.0 (-12.7 to 27.8) mL/m(2) /year. Fifteen subjects were in Group I and 46 in Group II. RV iEDV, RV ejection fraction, RV indexed end-systolic volume (iESV) were significantly different between groups. By multivariable analysis, RV iESV was the only independent parameter associated with rapid RV dilation (P < 0.01). CONCLUSION: There was no significant change in RV iEDV in majority of repaired TOF subjects. RV iESV was the best parameter associated with more rapid RV dilation.

Rate of Change in Cardiac Magnetic Resonance Imaging Measures Is Associated With Death in Duchenne Muscular Dystrophy.

BACKGROUND: Cardiovascular disease is the leading cause of death among patients with Duchenne muscular dystrophy (DMD). Identifying patients at risk of early death could allow for increased monitoring and more intensive therapy. Measures that associate with death could serve as surrogate outcomes in clinical trials. METHODS AND RESULTS: Duchenne muscular dystrophy subjects prospectively enrolled in observational studies were included. Models using generalized least squares were used to assess the difference of cardiac magnetic resonance measurements between deceased and alive subjects. A total of 63 participants underwent multiple cardiac magnetic resonance imaging and were included in the analyses. Twelve subjects (19.1%) died over a median follow-up of 5 years (interquartile range, 3.1-7.0). Rate of decline in left ventricular ejection fraction was faster in deceased than alive subjects (P<0.0001). Rate of increase in indexed left ventricular end-diastolic (P=0.0132) and systolic (P<0.0001) volumes were higher in deceased subjects. Faster worsening in midcircumferential strain was seen in deceased subjects (P=0.049) while no difference in global circumferential strain was seen. The rate of increase in late gadolinium enhancement, base T1, and mid T1 did not differ between groups. CONCLUSIONS: Duchenne muscular dystrophy death is associated with the rate of change in left ventricular ejection fraction, midcircumferential strain, and ventricular volumes. Aggressive medical therapy to decrease the rate of progression may improve the mortality rate in this population. A decrease in the rate of progression may serve as a valid surrogate outcome for therapeutic trials.

Comparative effectiveness of virtual reality (VR) vs 3D printed models of congenital heart disease in resident and nurse practitioner educational experience.

BACKGROUND: Medical trainees frequently note that cardiac anatomy is difficult to conceive within a two dimensional framework. The specific anatomic defects and the subsequent pathophysiology in flow dynamics may become more apparent when framed in three dimensional models. Given the evidence of improved comprehension using such modeling, this study aimed to contribute further to that understanding by comparing Virtual Reality (VR) and 3D printed models (3DP) in medical education. OBJECTIVES: We sought to systematically compare the perceived subjective effectiveness of Virtual Reality (VR) and 3D printed models (3DP) in the educational experience of residents and nurse practitioners. METHODS: Trainees and practitioners underwent individual 15-minute teaching sessions in which features of a developmentally typical heart as well as a congenitally diseased heart were demonstrated using both Virtual Reality (VR) and 3D printed models (3DP). Participants then briefly explored each modality before filling out a short survey in which they identified which model (3DP or VR) they felt was more effective in enhancing their understanding of cardiac anatomy and associated pathophysiology. The survey included a binary summative assessment and a series of Likert scale questions addressing usefulness of each model type and degree of comfort with each modality. RESULTS: Twenty-seven pediatric residents and 3 nurse practitioners explored models of a developmentally typical heart and tetralogy of Fallot pathology. Most participants had minimal prior exposure to VR (1.1 ± 0.4) or 3D printed models (2.1 ± 1.5). Participants endorsed a greater degree of understanding with VR models (8.5 ± 1) compared with 3D Printed models (6.3 ± 1.8) or traditional models of instruction (5.5 ± 1.5) p < 0.001. Most participants felt comfortable with modern technology (7.6 ± 2.1). 87% of participants preferred VR over 3DP. CONCLUSIONS: Our study shows that, overall, VR was preferred over 3DP models by pediatric residents and nurse practitioners for understanding cardiac anatomy and pathophysiology.

Appropriateness of cardiovascular computed tomography and magnetic resonance imaging in patients with conotruncal defects.

BACKGROUND: To promote the rational use of cardiovascular imaging in patients with congenital heart disease, the American College of Cardiology developed Appropriate Use Criteria (AUC), but its clinical application and pre-release benchmarks have not been evaluated. We aimed to evaluate the appropriateness of indications for cardiovascular magnetic resonance (CMR) and cardiovascular computed tomography (CCT) in patients with conotruncal defects and to identify factors associated with maybe or rarely appropriate (M/R) indications. METHODS: Twelve centers each contributed a median of 147 studies performed prior to AUC publication (01/2020) on patients with conotruncal defects. To incorporate patient characteristics and center-level effects, a hierarchical generalized linear mixed model was used. RESULTS: Of the 1753 studies (80% CMR, and 20% CCT), 16% were rated M/R. Center M/R ranged from 4 to 39%. Infants accounted for 8.4% of studies. In multivariable analyses, patient- and study-level factors associated with M/R rating included: age <1 year (OR 1.90 [1.15-3.13]), truncus arteriosus (vs. tetralogy of Fallot, OR 2.55 [1.5-4.35]), and CCT (vs. CMR, OR 2.67 [1.87-3.83]). None of the provider- or center-level factors reached statistical significance in the multivariable model. CONCLUSIONS: Most CMRs and CCTs ordered for the follow-up care of patients with conotruncal defects were rated appropriate. However, there was significant center-level variation in appropriateness ratings. Younger age, CCT, and truncus arteriosus were independently associated with higher odds of M/R rating. These findings could inform future quality improvement initiatives and further exploration of factors resulting in center-level variation.

Impact of pulmonary hypertension on transplant outcomes in pediatric cardiomyopathy patients.

Controversy exists over whether PHTN in heart transplant candidates increases post-transplant mortality. We performed analysis of data reported to UNOS for children who underwent primary heart transplantation for cardiomyopathy from January 1994 to June 2010. Patients were divided into two groups depending on their pre-transplant TPG: no-PHTN (TPG ≤ 12 mmHg) and PHTN (TPG >12 mm Hg). A total of 6139 children underwent transplantation of whom 2456 (40%) were for cardiomyopathies; 1322 (54%) of these had catheterization data available. The PHTN group (mean TPG 19.5 ± 8.6) had 312 patients and no-PHTN (TPG 6.7 ± 4.0) had 1010. Mortality at one month (4.5% vs. 2.3%) and three months (6.1% vs. 3.1%) post-transplant was significantly higher in the PHTN than the no-PHTN group with an odds ratio of 2 (p < 0.05). There was no significant effect of PHTN on early mortality in children <1 yr age. There was no significant improvement in early survival for transplants performed after compared to before 2003 in patients with PHTN despite availability of pulmonary dilators. Pre-transplant PHTN increases early post-transplant mortality in pediatric cardiomyopathy patients above one yr of age. There has been no significant improvement in the outcome of this group over the last seven yr.