Impact of new allocation policy on waitlist and transplant outcomes of adult congenital heart patients supported with ECMO.

BACKGROUND: The use of ECMO as a bridge to heart transplantation has been growing rapidly in all heart transplant recipients since the implementation of the new UNOS allocation policy; however, the impact on adult congenital heart disease (ACHD) patients is not known. METHODS: We analyzed the UNOS data (2015-2021) for ACHD patients supported with extracorporeal membrane oxygenation (ECMO) during the waitlist, before and after October 2018, to assess the impact on the waitlist and posttransplant outcomes. We compared the characteristics and outcomes of ACHD patients with or without ECMO use during the waitlist and pre- and postpolicy changes. RESULTS: A total of 23 821 patients underwent heart transplantation, and only 918 (4%) had ACHD. Out of all ACHD patients undergoing heart transplants, 6% of patients in the prepolicy era and 7.6% in the postpolicy era were on ECMO at the time of listing. Those on ECMO were younger and sicker compared to the rest of the ACHD cohort. Those on ECMO had similar profiles pre- and postpolicy change; however, there was a very significant decrease in the waitlist time [136 days (IQR 29-384) vs. 38 days (IQR 11-108), p = 0.01]. There was no difference in waitlist mortality; however, competing risk analyses showed a higher likelihood of transplantation (51% vs. 29%) and a lower likelihood of death or deterioration (31% vs. 42%) postpolicy change. Long-term outcomes posttransplant for those supported with ECMO compared to the non-ECMO cohort are similar for ACHD patients, although there was higher attrition in the first year for the ECMO cohort. CONCLUSION: The new allocation policy has resulted in shorter waitlist times and a higher likelihood of transplantation for ACHD patients supported by ECMO. However, the appropriate use of ECMO and the underuse of durable circulatory support devices in this population need further exploration.

Cement-based solidification of nuclear waste: Mechanisms, formulations and regulatory considerations.

This review paper provides a comprehensive analysis of cement-based solidification and immobilisation of nuclear waste. It covers various aspects including mechanisms, formulations, testing and regulatory considerations. The paper begins by emphasizing the importance of nuclear waste management and the associated challenges. It explores the mechanisms and principles in cement-based solidification, with a particular focus on the interaction between cement and nuclear waste components. Different formulation considerations are discussed, encompassing factors such as cement types, the role of additives and modifiers. The review paper also examines testing and characterisation methods used to assess the physical, chemical and mechanical properties of solidified waste forms. Then the paper addresses the regulatory considerations and compliance requirements for cement-based solidification. The paper concludes by critically elaborating on the current challenges, emerging trends and future research needs in the field. Overall, this review paper offers a comprehensive overview of cement-based solidification, providing valuable insights for researchers, practitioners and regulatory bodies involved in nuclear waste management.

Roadmap to a net-zero carbon cement sector: Strategies, innovations and policy imperatives.

The cement industry plays a significant role in global carbon emissions, underscoring the urgent need for measures to transition it toward a net-zero carbon footprint. This paper presents a detailed plan to this end, examining the current state of the cement sector, its carbon output, and the imperative for emission reduction. It delves into various low-CO2 technologies and emerging innovations such as alkali-activated cements, calcium looping, electrification, and bio-inspired materials. Economic and policy factors, including cost assessments and governmental regulations, are considered alongside challenges and potential solutions. Concluding with future prospects, the paper offers recommendations for policymakers, industry players, and researchers, highlighting the roadmap's critical role in achieving a carbon-neutral cement sector.

Impact of induction therapy on cytomegalovirus infection and post-transplant outcomes in pediatric heart transplant recipients receiving routine antiviral prophylaxis.

OBJECTIVES: Induction therapy has been increasingly used in pediatric heart transplantation. This study evaluated the impact of anti-thymocyte globulin (ATG) versus basiliximab as induction therapy on post-transplant cytomegalovirus (CMV) infection, rejection at 1 year, coronary allograft vasculopathy (CAV), and mortality in pediatric heart transplant recipients receiving antiviral prophylaxis. RESULTS: Of the 96 patients (age < 18 years) analyzed, 46 (47.9%) patients received basiliximab, and 50 (52.1%) received ATG. Median follow-up was 3.0 (IQR, 1.7-4.9) years with 32.3% reporting CMV infection. The ATG group, as compared with the basiliximab group, had similar incidences of CMV infection (36% vs. 28.3%, p = .418), CMV viremia (22% vs. 19.6%, p = .769), and CMV-positive tissue biopsy (30% vs. 22%, p = .486). The ATG group had lower incidences of rejection at 1 year (16% vs. 36.9%, p = .022) and CAV (4% vs. 23.9%, p = .006) with no difference in mortality (8% vs. 15.2%, p = .343), compared with the basiliximab group. Multivariate analysis showed that induction with ATG was associated with a lower risk of rejection at 1 year (OR, .31; 95% CI, .09-.94; p = .039) with no impact on the incidences of CMV infection (HR, 2.06; 95% CI, .54-7.89; p = .292), CAV (HR, .30; 95% CI, .04-2.58; p = .275), and mortality (HR, .39; 95% CI, .09-1.82; p = .233) compared to basiliximab induction. DISCUSSION AND CONCLUSIONS: In conclusion, induction with ATG was associated with reduction in risk of rejection at 1 year with no effects on CMV infection, CAV, and mortality in pediatric heart transplant recipients with universal antiviral prophylaxis compared with basiliximab induction therapy.

Impact of 2016 UNOS pediatric heart allocation policy changes on VAD utilization, waitlist, and post-transplant survival outcomes in children with CHD versus Non-CHD.

AIMS: We analyzed the impact of the revised pediatric heart allocation policy on types of ventricular assist device (VAD) utilization, and waitlist (WL) and post-heart transplant (HT) survival outcomes in congenital heart disease (CHD) versus non-CHD patients before (Era-1) and after (Era-2) pediatric heart allocation policy implementation. METHODS: We retrospectively reviewed the UNOS database from December 16, 2011, through March 31, 2021, for patients < 18 years old and listed for primary HT. We compared the differences observed between Era-1 and Era-2. RESULTS: 5551 patients were listed for HT, of whom 2447(44%) were in Era-1 and 3104(56%) were in Era-2. CHD patients were listed as status 1A unchanged, but the number of patients listed as status 1B decreased in Era-2, whereas the number of non-CHD patients listed as status 1A decreased, but status 1B increased. In Era-2 compared to Era-1, both temporary (1% to 4%, p < .001) and durable VAD (13.6% to 17.8%, p < .001) utilization increased, and the transplantation rate per 100-patient years increased in both groups. The median WL period for CHD patients increased marginally from 70 to 71 days (p = .06), whereas for non-CHD patients it decreased from 61 to 54 days (p < .001). Adjusted 90-day WL survival increased from 84% to 88%, p = .016 in CHD, but there was no significant change in non-CHD patients (p = .57). There was no significant difference in 1-year post-HT survival in CHD and non-CHD patients between Era-1 and Era-2. CONCLUSIONS: In summary, after the revised heart allocation policy implementation, temporary and durable VAD support increased, HT rate increased, waitlist duration marginally increased in the CHD cohort and decreased in the non-CHD cohort, and 90-day WL survival probability improved in children with CHD without significant change in 1-year post-HT outcomes. Future studies are needed to identify changes to the policy that may further improve the listing criteria to improve WL duration and post-HT survival.

Explainable synthetic image generation to improve risk assessment of rare pediatric heart transplant rejection.

Expert microscopic analysis of cells obtained from frequent heart biopsies is vital for early detection of pediatric heart transplant rejection to prevent heart failure. Detection of this rare condition is prone to low levels of expert agreement due to the difficulty of identifying subtle rejection signs within biopsy samples. The rarity of pediatric heart transplant rejection also means that very few gold-standard images are available for developing machine learning models. To solve this urgent clinical challenge, we developed a deep learning model to automatically quantify rejection risk within digital images of biopsied tissue using an explainable synthetic data augmentation approach. We developed this explainable AI framework to illustrate how our progressive and inspirational generative adversarial network models distinguish between normal tissue images and those containing cellular rejection signs. To quantify biopsy-level rejection risk, we first detect local rejection features using a binary image classifier trained with expert-annotated and synthetic examples. We converted these local predictions into a biopsy-wide rejection score via an interpretable histogram-based approach. Our model significantly improves upon prior works with the same dataset with an area under the receiver operating curve (AUROC) of 98.84% for the local rejection detection task and 95.56% for the biopsy-rejection prediction task. A biopsy-level sensitivity of 83.33% makes our approach suitable for early screening of biopsies to prioritize expert analysis. Our framework provides a solution to rare medical imaging challenges currently limited by small datasets.

Heart Failure with Preserved Ejection Fraction in Children.

Diastolic dysfunction (DD) refers to abnormalities in the mechanical function of the left ventricle (LV) during diastole. Severe LVDD can cause symptoms and the signs of heart failure (HF) in the setting of normal or near normal LV systolic function and is referred to as diastolic HF or HF with preserved ejection fraction (HFpEF). Pediatric cardiologists have long speculated HFpEF in children with congenital heart disease and cardiomyopathy. However, understanding the risk factors, clinical course, and validated biomarkers predictive of the outcome of HFpEF in children is challenging due to heterogeneous etiologies and overlapping pathophysiological mechanisms. The natural history of HFpEF varies depending upon the patient's age, sex, race, geographic location, nutritional status, biochemical risk factors, underlying heart disease, and genetic-environmental interaction, among other factors. Pediatric onset HFpEF is often not the same disease as in adults. Advances in the noninvasive evaluation of the LV diastolic function by strain, and strain rate analysis with speckle-tracking echocardiography, tissue Doppler imaging, and cardiac magnetic resonance imaging have increased our understanding of the HFpEF in children. This review addresses HFpEF in children and identifies knowledge gaps in the underlying etiologies, pathogenesis, diagnosis, and management, especially compared to adults with HFpEF.

mRNA Coronavirus Disease 2019 Vaccine-Associated Myopericarditis in Adolescents: A Survey Study.

In this survey study of institutions across the US, marked variability in evaluation, treatment, and follow-up of adolescents 12 through 18 years of age with mRNA coronavirus disease 2019 (COVID-19) vaccine-associated myopericarditis was noted. Only one adolescent with life-threatening complications was reported, with no deaths at any of the participating institutions.

Contemporary outcomes of durable ventricular assist devices in adults with congenital heart disease as a bridge to heart transplantation.

OBJECTIVES: This study aimed to compare the clinical characteristics, risk factors, and overall survival outcomes in adults with congenital heart disease (ACHD) bridged to transplantation with a ventricular assist device (VAD) versus no-VAD. METHODS: The study included 894 ACHD patients aged ≥18 years listed for primary heart transplantation between 2010 and 2019 from the United Network for Organ Sharing database. Primary outcomes were waitlist and 1-year post-transplant mortality between VAD and no-VAD ACHD patients. RESULTS: Of 894 ACHD patients included in the study, 91(10.1%) had VAD support at the time of listing. Patients who needed VAD support were mostly males, heavier, and had higher pulmonary artery pressure than the no-VAD group at the listing. The overall waitlist mortality was 38% in the VAD group than 17% in the no-VAD group (p < 0.01). ECMO use was associated with significantly higher mortality than either group. There was no significant difference in 1-year post-transplant mortality between VAD versus no-VAD at the time of transplant (15% vs. 17%; p = 0.66). Multivariate regression analysis found that BMI <20 kg/m2 (hazard ratio (HR) 1.1; p = 0.01), bilirubin >2 mg/dl (HR 1.1; p = 0.03), creatinine >2 mg/dl (HR 1.3; p = 0.04) and ECMO at transplant (HR 1.4; p = 0.03) increased early post-transplant mortality. CONCLUSIONS: The one-year post-transplant mortality rate was no different for ACHD patients that received VAD versus no-VAD. These findings suggest that a VAD should be considered an option to support ACHD patients as a bridge to heart transplantation.

SARS-CoV-2 infection induced thyroid storm and heart failure in an adolescent girl.

We report a case of thyroid storm precipitated by SARS-CoV-2 infection in an adolescent girl with a history of Graves disease and dilated cardiomyopathy. This case highlights that SARS-CoV-2 infection can potentially trigger a thyrotoxicosis crisis and acute decompensated heart failure in a patient with underlying thyroid disease and myocardial dysfunction even in the absence of multi-system inflammatory syndrome in children. We systematically reviewed the thyrotoxicosis cases with SARS-CoV-2 infection and described its impact on pre-existing dilated cardiomyopathy.

Myopericarditis after messenger RNA Coronavirus Disease 2019 Vaccination in Adolescents 12 to 18 Years of Age.

OBJECTIVES: To characterize the clinical course and outcomes of children 12-18 years of age who developed probable myopericarditis after vaccination with the Pfizer-BioNTech (BNT162b2) coronavirus disease 2019 (COVID-19) messenger RNA (mRNA) vaccine. STUDY DESIGN: A cross-sectional study of 25 children, aged 12-18 years, diagnosed with probable myopericarditis after COVID-19 mRNA vaccination as per the Centers for Disease Control and Prevention criteria for myopericarditis at 8 US centers between May 10, 2021, and June 20, 2021. We retrospectively collected the following data: demographics, severe acute respiratory syndrome coronavirus 2 virus detection or serologic testing, clinical manifestations, laboratory test results, imaging study results, treatment, and time to resolutions of symptoms. RESULTS: Most (88%) cases followed the second dose of vaccine, and chest pain (100%) was the most common presenting symptom. Patients came to medical attention a median of 2 days (range, <1-20 days) after receipt of Pfizer mRNA COVID-19 vaccination. All adolescents had an elevated plasma troponin concentration. Echocardiographic abnormalities were infrequent, and 92% showed normal cardiac function at presentation. However, cardiac magnetic resonance imaging, obtained in 16 patients (64%), revealed that 15 (94%) had late gadolinium enhancement consistent with myopericarditis. Most were treated with ibuprofen or an equivalent nonsteroidal anti-inflammatory drug for symptomatic relief. One patient was given a corticosteroid orally after the initial administration of ibuprofen or an nonsteroidal anti-inflammatory drug; 2 patients also received intravenous immune globulin. Symptom resolution was observed within 7 days in all patients. CONCLUSIONS: Our data suggest that symptoms owing to myopericarditis after the mRNA COVID-19 vaccination tend to be mild and transient. Approximately two-thirds of patients underwent cardiac magnetic resonance imaging, which revealed evidence of myocardial inflammation despite a lack of echocardiographic abnormalities.

Interplay between donor and recipient factors impacts outcomes after pediatric heart transplantation: An analysis from the united network for organ sharing database.

BACKGROUND: Donor utilization rates continue to be low for pHT, however, efforts to expand the donor acceptance criteria have shown mixed results in single-institution studies in pediatric and adult transplantation. Purpose of this study is to assess impact of individual and cumulative donor risk factors on transplant outcomes as well as the interplay between donor and recipient risk factors as it relates to transplant outcomes. METHOD: We analyzed pHT UNOS data (2008-2018) to compare the recipient characteristics, donor characteristics, and outcomes based on donor ejection fraction of less than 50% (low EF) and or ischemic time of greater than 4 hours (prolonged IT). RESULTS: A total of 4345 pHT were performed of which 1309 (30.1%) were with prolonged IT and 122 (2.8%) in low EF. Additionally, 58 (1.3%) were performed with both low EF and prolonged IT (combined risk). Rest (2856 patients, 65.7%) was considered low risk. Recipients of combined risk were more likely to be younger, have post-surgical congenital heart disease, be on ECMO or ventilator but less likely on VAD (all P < .01) compared with any other group. Waitlist time was significantly lower for low EF (mean 39 days, 15-109) or combined risk group (36 days, range 15-80) compared with other groups (60 days, range 23-125) (P = .01). 1-year mortality was 8% in low-risk group, 12% in prolonged IT, 14% in reduced EF, and 28% in combined risk patients (P < .01). Number of treated rejections in one year were significantly higher in prolonged IT and combined risk group compared to other groups (P < .01). When stratified by recipient risk, there was no difference in outcomes for low risk, prolonged IT, or low EF groups; however, there were significant survival differences for high-risk recipient versus low-risk recipient in each donor group. CONCLUSION: Lower EF donors performed similar to prolonged IT donor, but were uncommonly used. Acceptance of risk was common in recipients deemed higher risk for waitlist mortality and led to shorter wait times. Caution should be used in accepting combined risk transplants. The recipient risk factors have significant impact on outcomes across all donor risk groups and further analysis will help balance the waitlist mortality with post-transplant outcomes.

Impact of peak respiratory exchange ratio on the prognostic power of symptoms-limited exercise testing using Bruce protocol in patients with Fontan physiology.

OBJECTIVES: We evaluated the impact of peak respiratory exchange ratio on the prognostic values of cardiopulmonary exercise variables during symptoms-limited incremental exercise tests in patients with Fontan physiology. METHODS: Retrospective single-centre chart review study of Fontan patients who underwent exercise testing using the Bruce protocol between 2014 and 2018 and follow-up. RESULTS: A total of 34 patients (age > 18 years) had a Borg score of ≥7 on the Borg 10-point scale, but only 50% of patients achieved a peak respiratory exchange ratio of ≥ 1.10 (maximal test). Peak oxygen consumption, percent-predicted peak oxygen consumption, and peak oxygen consumption at the ventilatory threshold was reduced significantly in patients with a peak respiratory exchange ratio of < 1.10. Peak oxygen consumption and percent-predicted peak oxygen consumption was positively correlated with peak respiratory exchange ratio values (r = 0.356, p = 0.039). After a median follow-up of 21 months, cardiac-related events occurred in 16 (47%) patients, with no proportional differences in patients due to their respiratory exchange ratio (odds ratio, 0.62; 95% CI: 0.18-2.58; p = 0.492). Multivariate Cox proportional hazard analysis showed percent-predicted peak oxygen consumption, peak heart rate, and the oxygen uptake efficient slope were highly related to the occurrence of events in patients only with a peak respiratory exchange ratio of ≥ 1.10. CONCLUSIONS: The value of peak cardiopulmonary exercise variables is limited for the determination of prognosis and assessment of interventions in Fontan patients with sub-maximal effort. Our findings deserve further research and clinical application.

Maximal versus sub-maximal effort during cardiopulmonary exercise testing in adults with congenital heart disease: outcome analysis of short-term cardiac-related events.

Peak respiratory exchange ratio is an objective marker of patient effort during cardiopulmonary exercise testing. We evaluated exercise variables in 175 adult congenital heart disease patients and the impact of respiratory exchange ratio on the prognostic value of exercise variables for short-term cardiac-related events. Of 175 patients, 110 completed the exercise test with a peak respiratory exchange ratio of ≥1.10 and the remaining 65 had a peak respiratory exchange ratio of <1.10. Peak oxygen consumption, the percentage of oxygen consumption at the ventilatory threshold, peak heart rate, percentage predicted peak heart rate, double product, oxygen uptake efficiency slope, and the number of patients with exercise oscillatory ventilation were reduced significantly in patients with a respiratory exchange ratio of <1.10 compared to those with a respiratory exchange ratio of ≥1.10. After a median follow-up of 21 months, total cardiac-related events occurred in 37 (21%) patients. Multivariate Cox proportional hazard analysis showed that the percentage predicted peak oxygen consumption, and oxygen uptake efficiency slope were independent predictors of cardiac-related events only in patients with a peak respiratory exchange ratio of ≥1.10. Sub-maximal exercise performance can be preserved in adult congenital heart disease patients. The percentage predicted oxygen consumption and the oxygen uptake efficiency slope are two independent predictors for short-term cardiac-related events in adult congenital heart disease patients.

Cytomegalovirus infection and allograft rejection among pediatric heart transplant recipients in the era of valganciclovir prophylaxis.

CMV infection remains a significant cause of morbidity among pediatric HTx recipients We explored the implications of CMV infection on post-transplant outcomes among CMV risk-stratified pediatric HTx recipients receiving VGC prophylaxis. Children who underwent HTx between January 2010 and October 2016 were stratified according to CMV risk at time of transplant and evaluated for evidence of post-transplant CMV infection, rejection, CAV, and graft loss. Among 97 children, 41 (42%) were considered HR or IR risk for CMV infection and received VGC prophylaxis. CMV DNAemia was observed in 34% of children, including 71% HR, 40% IR, and 18% LR individuals. Median time to CMV DNAemia following VGC prophylaxis was 32D among HR vs 277D in IR subjects (P = .042). No difference in overall graft loss was noted among groups, but CMV HR children had decreased rejection-free survival (3.5 years) compared to IR (6 years, P = .015) and LR children (8 years, P = .0003). CMV was noted on EMB in 13% of children but was not associated with increased CAV, rejection or graft loss. High-risk CMV status was associated with decreased time to CMV infection despite VGC prophylaxis, compared to IR, and decreased rejection-free survival times compared to both IR and LR recipients. Detection of CMV on EMB was not associated with increased rejection, CAV or graft loss. Additional studies are needed to explore the impact of CMV infection on rejection-free survival in HTx recipients.

Correlation of gene expression profiling score, cardiac hemodynamics and echocardiographic parameters in asymptomatic, rejection-free pediatric heart transplant recipients.

OBJECTIVES: To correlate gene expression profiling scores obtained by AlloMap® with cardiac hemodynamics, cardiac allograft vasculopathy (CAV), and echocardiographic parameters in asymptomatic, rejection-free pediatric heart transplant (HT) recipients. METHODS: Single-institution retrospective study of 210 AlloMap scores obtained concomitantly with cardiac catheterization and echocardiogram from 55 children during follow-up after cardiac transplantation. RESULTS: The median age at HT was 5.1 years (range, 0.9-14.1), with 29 males and 26 females. AlloMap scores were high in <2 years vs ≥2 years of age at the time of HT (P = .001), and trending higher with time after HT (R2  = .04, P = .004). There was no significant difference in scores between ACR grades 0 and 1R or CAV. There was mild to modest correlation of AlloMap scores with the mean right atrial pressure (P = .002), and pulmonary capillary wedge pressure (P = .02), but no correlation was found with LV SF% (P = .3), LV EF% (P = .5), or RV FAC % (P = .8). CONCLUSIONS: Our study provides preliminary data that the AlloMap score must be studied carefully before it can be used in children, particularly in those under 2 years of age. Monitoring of serial scores for each patient could potentially reflect changes in allograft performance that may determine indications for catheterization and biopsy which needs to be validated in future studies.

Pediatric cardiac waitlist mortality-Still too high.

Cardiac transplantation for children with end-stage cardiac disease with no other medical or surgical options is now standard. The number of children in need of cardiac transplant continues to exceed the number of donors considered "acceptable." Therefore, there is an urgent need to understand which recipients are in greatest need of transplant before becoming "too ill" and which "marginal" donors are acceptable in order to reduce waitlist mortality. This article reviewed primarily pediatric studies reported over the last 15 years on waitlist mortality around the world for the various subgroups of children awaiting heart transplant and discusses strategies to try to reduce the cardiac waitlist mortality.

Use of the terminal complement inhibitor eculizumab in paediatric heart transplant recipients.

Antibody-mediated rejection is a major clinical challenge that limits graft survival. Various modalities of treatment have been reported in small studies in paediatric heart recipients. A novel approach is to use complement-inhibiting agents, such as eculizumab, which inhibits cleavage of C5 to C5a thereby limiting the formation of membrane attack complex and terminal complement-mediated injury of tissue-bound antibodies. This medical modality of treatment has theoretical advantages but the collective experience in its use in the solid organ transplant community remains small. We add to this experience by combining 14 cases from 6 paediatric heart centres in this descriptive study.

COVID-19 and Pulmonary Hypertension in Children: What Do We Know So Far?

The interplay between coronavirus disease 2019 (COVID-19) and pulmonary hypertension (PH) in children is unknown. Adults with PH are at potential risk for severe complications and high mortality due to associated comorbidities. It is difficult to extrapolate the outcomes of COVID-19 in adults to pediatric PH patients. Overall, a small number of COVID-19 cases is reported in patients with preexisting PH. Several factors may be responsible for the low incidence of COVID-19 in children with PH. Pulmonary hypertension is a rare disease, testing is not universal, and patients may have followed more rigorously the Center for Disease Control's guidelines recommended for personal protection with mask-wearing, social distancing, and hand sanitization through ongoing health education. The small number of COVID-19 cases in patients with preexisting PH does not support that PH is protective for COVID-19. However, medications used to treat PH may have some protection against COVID-19. This review discusses the pathophysiology of PH occurring with COVID-19, differences between children and adults with COVID-19, strategies for management of preexisting PH in children during the ongoing pandemic, and its impact within the field of PH.

Segmental Pulmonary Hypertension in Children with Congenital Heart Disease.

Segmental pulmonary hypertension is a complex condition in children that encompasses many congenital heart diseases including pulmonary atresia with ventricular septal defect, hemitruncus/truncus arteriosus with branch pulmonary artery stenosis, unilateral absent pulmonary artery, and several post-tricuspid shunt lesions. Multimodality imaging is required to confirm and assess pulmonary vascular disease in subjects with major aorto-pulmonary collaterals. We describe 3 children with complex congenital heart defects who have a variable degree of segmental pulmonary hypertension and discuss management strategies and the role of interventional and/or pulmonary hypertension targeted therapies.