Central Venous Pressure and Impaired Renal Function in Children and Young Adults With Cardiovascular Disease.

Background: Traditionally, low cardiac output has been considered the primary hemodynamic driver of renal function and injury. Adult data suggest that central venous pressure (CVP) is a more important factor. Objectives: The authors hypothesized that in children with cardiovascular disease, higher CVP predicts lower estimated glomerular filtration rate (eGFR) and worsening renal function (WRF). Methods: We performed a single-center cohort study of patients aged 3 months to 21 years with biventricular circulation undergoing cardiac catheterization. Pearson's correlation and linear and Cox regression analyses were performed to determine associations with eGFR at the time of catheterization and WFR within 180 days after catheterization. Results: 312 patients had median age 7.9 years (IQR: 2.3 to 14.5 years), median eGFR 97 mL/min/1.73 m2 (IQR: 81-118 mL/min/1.73 m2), median CVP 7 mm Hg (IQR: 5-9 mm Hg), and median cardiac index 3.7 mL/min/m2 (IQR: 2.9-4.6 mL/min/m2). Nearly half (48%) were transplant recipients. In multivariable analysis, CVP was independently associated with eGFR (ß = -2.65; 95% CI: -4.02, -1.28; P < 0.001), as was being a transplant recipient (ß = -10.20; 95% CI: -17.74, -2.65; P = 0.008), while cardiac index was not. Fifty-one patients (16%) developed WRF. In a proportional hazards model adjusting for cardiac index, only higher CVP (HR: 1.10; 95% CI: 1.04-1.17; P = 0.002) and greater contrast volume by weight (HR: 1.05; 95% CI: 1.01-1.10; P = 0.021) predicted WRF. CVP ≥7 mm Hg likewise predicted WRF (HR: 2.57; 95% CI: 1.29-5.12; P = 0.007). Conclusions: Among children with a spectrum of cardiovascular disease, higher CVP is associated with lower eGFR and development of WRF, independent of cardiac index.

Clinical Presentation, Classification, and Outcomes of Cardiogenic Shock in Children.

BACKGROUND: Despite growing cardiogenic shock (CS) research in adults, the epidemiology, clinical features, and outcomes of children with CS are lacking. OBJECTIVES: This study sought to describe the epidemiology, clinical presentation, hospital course, risk factors, and outcomes of CS among children hospitalized for acute decompensated heart failure (ADHF). METHODS: We examined consecutive ADHF hospitalizations (<21 years of age) from a large single-center retrospective cohort. Patients with CS at presentation were analyzed and risk factors for CS and for the primary outcome of in-hospital mortality were identified. A modified Society for Cardiovascular Angiography and Interventions shock classification was created and patients were staged accordingly. RESULTS: A total of 803 hospitalizations for ADHF were identified in 591 unique patients (median age 7.6 years). CS occurred in 207 (26%) hospitalizations. ADHF hospitalizations with CS were characterized by worse systolic function (P = 0.040), higher B-type natriuretic peptide concentration (P = 0.032), and more frequent early severe renal (P = 0.023) and liver (P < 0.001) injury than those without CS. Children presenting in CS received mechanical ventilation (87% vs 26%) and mechanical circulatory support (45% vs 16%) more frequently (both P < 0.001). Analyzing only the most recent ADHF hospitalization, children with CS were at increased risk of in-hospital mortality compared with children without CS (28% vs 11%; OR: 1.91; 95% CI: 1.05-3.45; P = 0.033). Each higher CS stage was associated with greater inpatient mortality (OR: 2.40-8.90; all P < 0.001). CONCLUSIONS: CS occurs in 26% of pediatric hospitalizations for ADHF and is independently associated with hospital mortality. A modified Society for Cardiovascular Angiography and Interventions classification for CS severity showed robust association with increasing mortality.

Long-term kidney outcomes in pediatric continuous-flow ventricular assist device patients.

BACKGROUND: Continuous-flow ventricular assist devices (CF-VADs) are used increasingly in pediatric end-stage heart failure (ESHF) patients. Alongside common risk factors like oxidant injury from hemolysis, non-pulsatile flow constitutes a unique circulatory stress on kidneys. Post-implantation recovery after acute kidney injury (AKI) is commonly reported, but long-term kidney outcomes or factors implicated in the evolution of chronic kidney disease (CKD) with prolonged CF-VAD support are unknown. METHODS: We studied ESHF patients supported > 90 days on CF-VAD from 2008 to 2018. The primary outcome was CKD (per Kidney Disease Improving Global Outcomes (KDIGO) criteria). Secondary outcomes included AKI incidence post-implantation and CKD evolution in the 6-12 months of CF-VAD support. RESULTS: We enrolled 134 patients; 84/134 (63%) were male, median age was 13 [IQR 9.9, 15.9] years, 72/134 (54%) had preexisting CKD at implantation, and 85/134 (63%) had AKI. At 3 months, of the 91/134 (68%) still on a CF-VAD, 34/91 (37%) never had CKD, 13/91 (14%) developed de novo CKD, while CKD persisted or worsened in 49% (44/91). Etiology of heart failure, extracorporeal membrane oxygenation use, duration of CF-VAD, AKI history, and kidney replacement therapy were not associated with different CKD outcomes. Mortality was higher in those with AKI or preexisting CKD. CONCLUSIONS: In the first multicenter study to focus on kidney outcomes for pediatric long-term CF-VAD patients, preimplantation CKD and peri-implantation AKI were common. Both de novo CKD and worsening CKD can happen on prolonged CF-VAD support. Proactive kidney function monitoring and targeted follow-up are important to optimize outcomes.

Research Gaps in Pediatric Heart Failure: Defining the Gaps and Then Closing Them Over the Next Decade.

Given the numerous opportunities and the wide knowledge gaps in pediatric heart failure, an international group of pediatric heart failure experts with diverse backgrounds were invited and tasked with identifying research gaps in each pediatric heart failure domain that scientists and funding agencies need to focus on over the next decade.

Decreased Heart Rate Variability in Children with Acute Decompensated Heart Failure is Associated with Poor Outcomes.

Heart rate variability (HRV) is a noninvasive indicator of the health of neurocardiac interactions of the autonomic nervous system. In adults, decreased HRV correlates with increased cardiovascular mortality. However, the relationship between HRV and outcomes in children with acute decompensated heart failure (ADHF) has not been described. Patients < 21 years old hospitalized with ADHF from 2013 to 2019 were included (N = 79). Primary outcome was defined as death, heart transplant, or mechanical circulatory support (MCS). The median standard deviation of the R-to-R interval in 5-min intervals (SDNN) was calculated from telemetry data obtained across the first 24 h of admission. Patients who met the primary outcome had significantly lower median SDNN (13.8 [7.8, 29.1]) compared to those who did not (24.6 [15.3, 84.4]; p = 0.004). A median SDNN of 20 ms resulted in a sensitivity of 68% and specificity of 69%. Median SDNN < 20 ms represented decreased freedom from primary outcome (p = 0.043) and a hazard ratio of 2.2 in multivariate analysis (p = 0.016). Pediatric patients with ADHF who died, underwent heart transplant, or required MCS had significantly decreased HRV at presentation compared to those that did not. This supports HRV as a noninvasive tool to improve prognostication in children in ADHF.

Atypical infiltrates on endomyocardial biopsy are associated with adverse outcomes in pediatric heart transplantation.

BACKGROUND: The significance of atypical infiltrates (eosinophils or plasma cells) on endomyocardial biopsy (EMB) after pediatric heart transplant (HTx) is not known. We hypothesized that atypical infiltrates are associated with worse post-HTx outcomes. METHODS: We performed a retrospective cohort study of consecutive patients <21 years old who underwent primary HTx between 2013 and 2017. Multiorgan transplants were excluded. The presence of atypical infiltrates and burden of atypical infiltrates (rare vs predominant) on EMB were recorded. Primary outcome was a composite of cardiac allograft vasculopathy, graft failure (relisting or retransplant), or death. Presence of atypical infiltrates was evaluated: (1) overall using Cox regression with time-dependent covariates and (2) if present by 1 year post-HTx using Kaplan-Meier analysis. RESULTS: Atypical infiltrates were present in 24 out of 95 patients (25%) and were associated with a higher likelihood of reaching the composite outcome (hazard ratio (HR) 6.22, 95% confidence interval (CI) 2.60-14.89, p < 0.0001). This persisted when controlling for rejection in multivariable analysis. There was also a greater risk of the composite outcome if ≥2 nonconsecutive EMBs had atypical infiltrates (HR 11.80, 95%CI 3.17-43.84, p = 0.0002) or if atypical infiltrates were the predominant feature on EMB (HR 30.58, 95%CI 9.34-100.06, p < 0.0001). Patients with atypical infiltrates by 1-year post-HTx had a 5-year freedom from the composite outcome of 48%, compared to 90% if no atypical infiltrates had been present by this timepoint (log rank p = 0.002). CONCLUSIONS: The presence of atypical infiltrates on EMB is associated with significantly worse outcomes in children following HTx. These patients require closer follow-up to assess for developing graft dysfunction.

Novel phenotype of aortic root dilatation and late-onset metabolic decompensation in a patient with TMEM70 deficiency.

TMEM70 deficiency causing mitochondrial complex V deficiency, nuclear type 2 (MIM: 614052) is the most common nuclear encoded defect affecting ATP synthase and has been well described in the literature as being characterized by neonatal or infantile onset of poor feeding, hypotonia, lethargy, respiratory compromise, heart failure, lactic acidosis, hyperammonemia, and 3-methylglutaconic aciduria progressing to a phenotype of developmental delay, failure to thrive, short stature, nonprogressive cardiomyopathy, microcephaly, facial dysmorphisms, hypospadias, persistent pulmonary hypertension of the newborn, and Wolff-Parkinson-White syndrome, as well as metabolic crises followed by developmental regression. The patient with TMEM70 deficiency herein reported has the unique presentation of aortic root dilatation, differing facial dysmorphisms, and no history of neonatal metabolic decompensation or developmental delay, as well as a plasma metabolomics signature, including elevated 3-methylglutaconic acid, 3-methylglutarylcarnitine, alanine, and lactate, in addition to the commonly described increased 3-methylglutaconic acid on urine organic acid analysis that helped aid in the diagnostic interpretation of variants of uncertain significance in TMEM70.

In vitro characterization on the role of APOE polymorphism in human hippocampal neurogenesis.

Hippocampal neurogenesis (HN) is considered an important mechanism underlying lifelong brain plasticity, and alterations in this process have been implicated in early Alzheimer's disease progression. APOE polymorphism is the most common genetic risk factor for late-onset Alzheimer's disease where the ε4 genotype is associated with a significantly earlier disease onset compared to the neutral ε3 allele. Recently, APOE has been shown to play an important role in the regulation of HN. However, the time-dependent impact of its polymorphism in humans remains elusive, partially due to the difficulties of studying human HN in vivo. To bridge this gap of knowledge, we used an in vitro cellular model of human HN and performed a time course characterization on isogenic induced pluripotent stem cells with different genotypes of APOE. We found that APOE itself was more highly expressed in ε4 at the stem cell stage, while the divergence of differential gene expression phenotype between ε4 and ε3 became prominent at the neuronal stage of differentiation. This divergence was not associated with the differential capacity to generate dentate gyrus granule cell-like neurons, as its level was comparable between ε4 and ε3. Transcriptomic profiling across different stages of neurogenesis indicated a clear "maturation of functional neurons" phenotype in ε3 neural progenitors and neurons, while genes differentially expressed only in ε4 neurons suggested potential alterations in "metabolism and mitochondrial function." Taken together, our in vitro investigation suggests that APOE ε4 allele can exert a transcriptome-wide effect at the later stages of HN, without altering the overall level of neurogenesis per se.

Post-operative dysnatremia is associated with adverse early outcomes after surgery for congenital heart disease.

BACKGROUND: Dysnatremia is a common disorder in critically ill surgical children. The study's aim is to determine the prevalence of dysnatremia and its association with outcomes after surgery for congenital heart disease (CHD). METHODS: This is a single-center retrospective cohort study of children <18 years of age undergoing surgery for CHD between January 2012 and December 2014. Multivariable logistic regression analysis was used to evaluate the relationship between dysnatremia and outcomes during the perioperative period. A total of 1345 encounters met the inclusion criteria. RESULTS: The prevalence of pre- and post-operative dysnatremia were 10.2% and 47.1%, respectively. Hyponatremia occurred in 19.1%, hypernatremia in 25.6%. Hypernatremia at 24, 48, and 72 h post-operative was associated with increased hospital mortality (odds ratios (OR) [95% confidence intervals (CI)] 3.08 [1.16-8.17], p = 0.024; 4.35 [1.58-12], p = 0.0045; 4.14 [1.32-12.97], p = 0.0148, respectively. Hypernatremia was associated with adverse neurological events 3.39 [1.12-10.23], p = 0.0302 at 48 h post-operative. Hyponatremia was not associated with any adverse outcome in our secondary analysis. CONCLUSIONS: Post-operative dysnatremia is a common finding in this heterogeneous cohort of pediatric cardiac-surgical patients. Hypernatremia was more prevalent than hyponatremia and was associated with adverse early post-operative outcomes. IMPACT: Our study has shown that dysnatremia was highly prevalent in children after congenital heart surgery with hypernatremia associated with adverse outcomes including mortality. It is important to understand fluid and sodium regulation in the post-operative period in children with congenital heart disease to better address fluid overload and associated electrolyte imbalances and acute kidney injury. While clinicians are generally very aware of the importance of hyponatremia in critically ill children, similar attention should be given to hypernatremia in this population.

Predicting progression to Alzheimer's disease with human hippocampal progenitors exposed to serum.

Adult hippocampal neurogenesis is important for learning and memory and is altered early in Alzheimer's disease. As hippocampal neurogenesis is modulated by the circulatory systemic environment, evaluating a proxy of how hippocampal neurogenesis is affected by the systemic milieu could serve as an early biomarker for Alzheimer's disease progression. Here, we used an in vitro assay to model the impact of systemic environment on hippocampal neurogenesis. A human hippocampal progenitor cell line was treated with longitudinal serum samples from individuals with mild cognitive impairment, who either progressed to Alzheimer's disease or remained cognitively stable. Mild cognitive impairment to Alzheimer's disease progression was characterized most prominently with decreased proliferation, increased cell death and increased neurogenesis. A subset of 'baseline' cellular readouts together with education level were able to predict Alzheimer's disease progression. The assay could provide a powerful platform for early prognosis, monitoring disease progression and further mechanistic studies.

Arrhythmogenic cardiomyopathy is under-recognized in end-stage pediatric heart failure: A 36-year single-center experience.

BACKGROUND: Although ventricular failure is a late finding in adults with AC, we hypothesize that this is a presenting symptom in pediatric heart failure patients who undergo HT and that their ventricular arrhythmia burden could differentiate AC from other cardiomyopathies. METHODS: We performed a single-center retrospective cohort study reviewing 457 consecutive pediatric (≤18 years) HT recipients at our institution. Explanted hearts were examined to establish the primary diagnosis, based on pathologic findings. Demographic and clinical variables were compared between AC versus non-HCM cardiomyopathy cases. RESULTS: Forty-five percent (n = 205/457) had non-HCM cardiomyopathies as the underlying primary diagnosis. Ten cases (10/205 = 4.9%) were diagnosed with AC. All 10 had biventricular disease. In 8/10 patients (80%), AC diagnosis was unrecognized pre-HT. Compared with non-AC cardiomyopathies, the AC group was older at diagnosis (9.3 years vs. 4.3 years, p = .012) and transplant (11.1 years vs. 6.5 years, p = .010), had more ventricular arrhythmias (80.0% vs 32.8%, p = .003), and required more anti-arrhythmic use (80.0% vs 32.3%, p = .001). Genetic testing yielded causative pathogenic variants in all tested individuals (n = 5/5, 100%). CONCLUSION: AC is often an unrecognized cardiomyopathy pretransplant in children who undergo HT. Pediatric non-HCM phenotypes with heart failure who have a significant ventricular arrhythmia burden should be investigated for AC.

Relation of Low Chloride Concentration to Diuretic Efficiency and Transplant-Free Survival in Children Hospitalized With Heart Failure.

Serum chloride plays an important role in fluid homeostasis and is associated with impaired diuretic responsiveness and mortality in adults with heart failure (HF). We sought to characterize the relationship of serum chloride and diuretic efficiency (DE) and to determine its prognostic importance in children hospitalized with acute decompensated HF (ADHF). We studied DE, defined as net fluid output/kg+constant per mg of loop diuretic/kg, in 200 children hospitalized with ADHF. Median serum chloride at admission was 102 mmol/L (interquartile range 99 to 105 mmol/L), and hypochloremia (chloride ≤96 mmol/L) was present in 16% of the population at admission. Serum chloride correlated with serum sodium (r = 0.66; p < 0.001) and bicarbonate (r = -0.39; p < 0.001). In the adjusted analysis, lower chloride was associated with reduced DE (p < 0.001). Serum sodium was associated with DE on the unadjusted analysis; however, the association was eliminated when added to the model with chloride (p = 0.442). Lower chloride was also associated with features of inadequate decongestion during hospitalization: a positive fluid balance (p = 0.003), greater cumulative loop diuretic dose per weight (p = 0.001), addition of a thiazide diuretic during hospitalization (p < 0.001), less weight loss (p = 0.025), and longer length of stay (p = 0.003). Chloride concentration was independently associated with death or transplant 1 year after admission (hazard ratio 0.94; p < 0.001). As a dichotomous variable, hypochloremia was independently associated with reduced DE (p < 0.001) and decreased 1-year transplant-free survival (hazard ratio 2.3, p < 0.001). Lower serum chloride at hospital admission is strongly and independently associated with impaired DE and reduced transplant-free survival in children hospitalized with ADHF.

Attenuated transcriptional response to pro-inflammatory cytokines in schizophrenia hiPSC-derived neural progenitor cells.

Maternal immune activation (MIA) during prenatal development is an environmental risk factor for psychiatric disorders including schizophrenia (SZ). Converging lines of evidence from human and animal model studies suggest that elevated cytokine levels in the maternal and fetal compartments are an important indication of the mechanisms driving this association. However, there is variability in susceptibility to the psychiatric risk conferred by MIA, likely influenced by genetic factors. How MIA interacts with a genetic profile susceptible to SZ is challenging to test in animal models. To address this gap, we examined whether differential gene expression responses occur in forebrain-lineage neural progenitor cells (NPCs) derived from human induced pluripotent stem cells (hiPSC) generated from three individuals with a diagnosis of schizophrenia and three healthy controls. Following acute (24 h) treatment with either interferon-gamma (IFNγ; 25 ng/µl) or interleukin (IL)-1ß (10 ng/µl), we identified, by RNA sequencing, 3380 differentially expressed genes (DEGs) in the IFNγ-treated control lines (compared to untreated controls), and 1980 DEGs in IFNγ-treated SZ lines (compared to untreated SZ lines). Out of 4137 genes that responded significantly to IFNγ across all lines, 1223 were common to both SZ and control lines. The 2914 genes that appeared to respond differentially to IFNγ treatment in SZ lines were subjected to a further test of significance (multiple testing correction applied to the interaction effect between IFNγ treatment and SZ diagnosis), yielding 359 genes that passed the significance threshold. There were no differentially expressed genes in the IL-1ß-treatment conditions after Benjamini-Hochberg correction. Gene set enrichment analysis however showed that IL-1ß impacts immune function and neuronal differentiation. Overall, our data suggest that a) SZ NPCs show an attenuated transcriptional response to IFNγ treatment compared to controls; b) Due to low IL-1ß receptor expression in NPCs, NPC cultures appear to be less responsive to IL-1ß than IFNγ; and c) the genes differentially regulated in SZ lines - in the face of a cytokine challenge - are primarily associated with mitochondrial, "loss-of-function", pre- and post-synaptic gene sets. Our findings particularly highlight the role of early synaptic development in the association between maternal immune activation and schizophrenia risk.

Bivalirudin or Unfractionated Heparin for Anticoagulation in Pediatric Patients on Continuous Flow Ventricular Assist Device Support: Single-Center Retrospective Cohort Study.

OBJECTIVES: Bivalirudin is a direct thrombin inhibitor that is being increasingly used for anticoagulation in children after ventricular assist device (VAD) implantation. While the data on bivalirudin use in pulsatile flow VADs are growing, reports on its use in patients on continuous flow (CF) VAD as well as comparisons of associated outcomes with unfractionated heparin (UFH) remain limited. DESIGN: Retrospective cohort study. SETTING: Single tertiary-quaternary referral center. PATIENTS: All patients less than 21 years old on CF-VAD support who received bivalirudin or UFH for anticoagulation between the years 2016 and 2020. INTERVENTIONS: Not applicable. MEASUREMENTS AND MAIN RESULTS: Clinical characteristics compared between the cohorts included time to target range of anticoagulation, markers of hemolysis, and prevalence of hemocompatibility-related adverse events such as major hemorrhagic complications, ischemic stroke, and pump thrombosis. In 42 unique patients (41 HeartWare HVAD [Medtronic, Minneapolis, MN], one HeartMate 3 LVAD [Abbott Laboratories, Abbott Park, IL]) during the study period, a total of 67 encounters of IV anticoagulation infusions (29 UFH and 38 bivalirudin) were retrospectively reviewed. In comparison with use of UFH, bivalirudin was associated with lesser odds of major bleeding complications (odds ratio [OR], 0.29; 95% CI, 0.09-0.97; p = 0.038). We failed to identify any difference in odds of major thrombotic complications (OR, 2.53; 95% CI, 0.47-13.59; p = 0.450). Eight of the patients (28%) on UFH were switched to bivalirudin due to hemorrhagic or thrombotic complications or inability to achieve therapeutic anticoagulation, while two of the patients (5%) on bivalirudin were switched to UFH due to hemorrhagic complications. Bivalirudin was used for a "washout" in eight cases with concern for pump thrombosis-six had resolution of the pump thrombosis, while two needed pump exchange. CONCLUSIONS: Use of bivalirudin for anticoagulation in patients on CF-VAD support was associated with lesser odds of hemorrhagic complications compared with use of UFH. Bivalirudin "washout" was successful in medical management of six of eight cases of possible pump thrombosis.

Cell line specific alterations in genes associated with dopamine metabolism and signaling in midbrain dopaminergic neurons derived from 22q11.2 deletion carriers with elevated dopamine synthesis capacity.

Microdeletions at the 22q11.2 locus are associated with increased risk for schizophrenia. Recent work has demonstrated that antipsychotic naïve 22q11.2 carriers display elevated levels of dopamine synthesis capacity (DSC) as assessed by 18F-DOPA PET imaging. While this is consistent with a role for abnormal dopamine function in schizophrenia, it is unclear what molecular changes may be associated with this neuro-imaging endophenotype, and moreover, if these alterations occur independently of clinical presentation. We therefore conducted a pilot study in which we generated human induced pluripotent stem cells (hiPSCs) from two 22q11.2 deletion carriers with elevated DSC in vivo, but distinct clinical presentations. From these and neurotypical control lines we were able to robustly generate midbrain dopaminergic neurons (mDA-neurons). We then assessed whether genes associated with dopamine synthesis, metabolism or signaling show altered expression between genotypes and further between the 22q11.2 deletion lines. Our data showed alterations in expression of genes associated with dopamine metabolism and signaling that differed between the two 22q11.2 hiPSC lines with distinct clinical presentations. This reinforces the importance of considering clinical, genetic and molecular information, when possible, when choosing which donors to generate hiPSCs from, to carry out mechanistic studies.

Ventricular assist device support for children with chemotherapy-induced cardiomyopathy and advanced heart failure: Perspectives gained from a single-center experience.

BACKGROUND: Guidance and data on ventricular assist device (VAD) support for children with chemotherapy-induced cardiomyopathy, particularly within the first 2 years after chemotherapy, are limited. METHODS: We performed a single-center retrospective case series, reviewing medical records of children <18 years of age with chemotherapy-induced cardiomyopathy and advanced heart failure (HF) who received durable VAD support. RESULTS: Six patients met inclusion criteria-5 HeartWare™ HVAD, 1 Berlin Heart EXCOR® . Median age at cancer diagnosis was 6 years (IQR 4.5-10 years). Median dose of anthracycline received was 540 mg/m2 (IQR 450-630 mg/m2 ). All patients developed HF within 1 year after initiation of cancer treatment (median 8 months, IQR 6-11.5 months) and were initiated on durable VAD support at a median of 8 months after completion of cancer treatment (IQR 3.3-43.5 months). Four patients had significant right ventricular dysfunction needing oral pulmonary vasodilator therapy, one patient had a major bleeding complication, and two patients had thromboembolic strokes while on VAD support. Median duration of VAD support was 7.5 months (IQR 3-11.3 months). Two patients underwent VAD explant due to recovery of LV function, one died due to cancer progression, and three underwent heart transplantation. CONCLUSIONS: Durable VAD support should be considered as a therapeutic option for children who have advanced HF due to chemotherapy-induced cardiomyopathy, even within 2 years of completing cancer treatment. A multi-disciplinary approach is essential for appropriate patient selection prior to implant and to ensure comprehensive care throughout the duration of VAD support.

Does Cardiac Catheterization Facilitate Hemodynamic Optimization of Pediatric Patients on Continuous-Flow Ventricular Assist Devices?

Understanding optimal ventricular assist device (VAD) parameters for pediatric patients is valuable given the inherent issue of patient-device size mismatch and heterogeneous cardiac anatomy in children. We evaluated our center's experience of continuous-flow VAD (CF-VAD) optimization using cardiac catheterization. We performed a retrospective analysis of all patients on CF-VAD support who underwent hemodynamic heart catheterization from 2013 to 2018. Fifteen patients had 16 hemodynamic catheterizations performed. The indications for hemodynamic optimization by catheterization included clinical signs of heart failure while on CF-VAD (9 of 16, 56%), pretransplant evaluation of pulmonary hypertension (2 of 16, 13%), or assessment of myocardial recovery (5 of 16, 31%). The median age at catheterization was 12 years (interquartile range: 8-16). Median baseline speed of device was 2333 ± 253 rotations per minute. The goal was to find the speed at which optimal hemodynamics were achieved, defined by low wedge pressure with an acceptable central venous pressure. Of the 16 catheterizations, there were 9 (56%) speed increases to achieve optimal hemodynamics and 5 (33%) speed decreases for hemodynamic optimization or for potential explant. The speed was not changed in 2 (13%) catheterizations as the patients were determined to be at an optimal hemodynamic state. Overall, VAD settings were optimized in 75% (14 of 16) of hemodynamic catheterizations. There were no adverse events related to catheterization. Thus, we conclude that catheterization-based hemodynamic assessment is safe and effective for optimizing VAD speed and provides guidance on medical management in children supported on CF-VAD.

Hemodynamic instability during connection to continuous kidney replacement therapy in critically ill pediatric patients.

BACKGROUND: Emerging data suggest evidence of organ hypoperfusion during continuous kidney replacement therapy (CKRT). To facilitate kidney and global recovery, we must understand the hemodynamic risks associated with CKRT. We aimed to investigate frequency of hemodynamic instability and association with patient outcomes in pediatric CKRT. METHODS: In a single-center study of CKRT patients between September 2016 and October 2018, we collected hemodynamic data using archived high-resolution physiologic data before and after connection. Primary outcome was hypotension defined as ≥ 20% decrease in baseline mean arterial pressure (MAP) for ≥ 2 consecutive minutes in the 60 min following connection. Secondary outcomes were tachycardia (≥ 20% increase in heart rate (HR)) and hemodynamic interventions. RESULTS: Seventy-one patients median age 54 months (IQR 7-144), weight 16.7 kg (IQR 8-41), on hemodiafiltration had 304 filter connections, 4 (IQR 1-7) filters per patient; the median duration of CKRT was 9 days (IQR 3-20). The most common CKRT indication was AKI with fluid overload (48/71, 69%). There were 78 (27%) hypotension and 42 (14%) tachycardia events; cumulative duration of hypotension was 14 min IQR (3-31.75). Teams provided intervention in 17/304 (6%) of connections. Pediatric Logistic Organ Dysfunction 2 was the only independent predictor of hypotension (aOR 2.12 (CI 1.02-4.41)). CONCLUSIONS: One in four and one in six pediatric CKRT filter connections were complicated by hypotension and tachycardia, respectively. Higher illness severity at CKRT initiation was independently associated with hypotension. Impact of CKRT-associated hemodynamic instability on global patient outcomes requires further targeted study. A higher resolution version of the Graphical abstract is available as Supplementary information.

Outcomes following use of pediatric and young adult donor hearts with bicuspid aortic valves: A single-center case series.

BACKGROUND: Valvular disease in pediatric and young adult donor hearts may be a relative contraindication to graft use. Outcomes following the use of donor hearts with bicuspid aortic valve (BAV) have not been previously reported in children. We describe 4 cases of pediatric heart transplantation (HTx) utilizing a donor heart with a BAV. CASE SERIES: Of the 469 HTx included in this study, 4 utilized a donor heart with a BAV. All recipients were female; median age was 11 years (range 0.3 to 19 years). In all cases, the BAV was not discovered until after HTx. All donors were less than 30 years old. The patients were followed for a median of 6 years (range 2 to 9 years) with all patients alive at last follow-up. Two patients have transitioned to adult care, and 2 patients continue to follow in our clinic. In follow-up, no patient has required an aortic valve intervention or had infective endocarditis. At last review, no patient had greater than mild aortic insufficiency or more than mild aortic stenosis. Three patients developed mild-to-moderate left ventricular hypertrophy in the first year post-transplant that improved over time. One patient experienced a peri-operative embolic stroke at time of transplant unrelated to the BAV. CONCLUSION: On short- and intermediate-term follow-up, pediatric and young adult donor hearts with BAV demonstrated acceptable graft longevity and valvular function. A functionally normal BAV in a pediatric heart transplant donor should not be a contraindication to organ acceptance.

Trends in Body Mass Index and Association With Outcomes in Pediatric Patients on Continuous Flow Ventricular Assist Device Support.

Data are limited regarding body mass index (BMI) in pediatric patients supported by ventricular assist devices (VAD) and associated clinical outcomes and complications. We performed a retrospective single-center cohort study including patients aged ≤21 years on durable continuous-flow VAD support for ≥30 days from 2009 to 2020. Patients were classified based on BMI percentile at implant using the US Centers for Disease Control and Prevention criteria: underweight (<5th percentile), healthy weight (5th-<85th percentile, reference group), overweight (85th-<95th percentile), and obese (≥95th percentile). Primary outcomes were hospital mortality and length of stay (LOS) after implant. Secondary outcomes included infectious complications and pump thrombosis. Seventy-two patients (58 HeartWare, 13 HeartMateII, 1 HeartMate3) were included. At implant, the study cohort comprised 13% underweight, 53% healthy weight, 18% overweight, and 17% obese. BMI increased across all categories during support, with 29% gaining BMI categories. No patients with obesity reduced their BMI category. At explant, the study cohort comprised 1% underweight, 54% healthy weight, 22% overweight, and 22% obese. There was no significant difference in hospital mortality, postoperative LOS, or pump thrombosis. Patients who were overweight had more frequent non-VAD infections. Patients with obesity required longer duration on VAD support and were less likely to be transplanted. We concluded that pediatric patients on VAD support who are overweight or have obesity do not improve their BMI and instead have significant increase. Larger studies are needed to assess the impact of abnormal BMI on VAD complications in pediatric patients.