Sharon Chen

How useful are B-type natriuretic peptide measurements for monitoring changes in patent ductus arteriosus shunt magnitude?

Objective:Although B-type natriuretic peptide (BNP) concentrations seem to be useful for detecting the presence of patent ductus arteriosus, there is no information about their usefulness for monitoring changes in PDA shunt magnitude.Study Design:We performed a retrospective analysis of paired BNP–echocardiogram measurements (obtained from infants (24 to 32 weeks gestation) with clinical suspicion of PDA).Result:Individual BNP concentrations (n=146, from 88 infants) were significantly related to shunt magnitude at the time of measurement and had good discriminating power for detecting a moderate-or-large shunt (area under receiver-operator characteristic curves (ROC-AUC)=0.85). In total, 36 infants had serial BNP–echocardiogram pairs (n=91) measured during their hospitalization. Changes (either increases or decreases) in BNP concentrations over time had only fair discriminating power (ROC-AUC=0.76) for detecting increases or decreases, respectively, in shunt magnitude.Conclusion:The high degree of variability in the BNP measurements made them less useful for monitoring changes in magnitude.

Outpatient Outcomes of Pediatric Patients with Left Ventricular Assist Devices.

Outpatient experience of children supported with continuous-flow ventricular assist devices (CF-VAD) is limited. We reviewed our experience with children discharged with CF-VAD support. All pediatric patients <18 years old with CF-VADs implanted at our institution were included. Discharge criteria included a stable medication regimen, completion of a VAD education program and standardized rehabilitation plan, and presence of a caregiver. Hospital readmissions (excluding scheduled admissions) were reviewed. Adverse events were defined by Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) criteria. Of 17 patients with CF-VADs, 8 (47%) were discharged from the hospital (1 HeartWare ventricular assist device (Heartware Inc., Framingham, MA), 7 HeartMate II (Thoratec Corp, Pleasanton, CA)). Median age was 15.3 (range 9.6–17.1) years and weight was 50.6 (33.6–141) kg. Device strategies were destination therapy (DT; n = 4) and bridge to transplant (n = 4). Patients spent a median 49 (26–107) days hospitalized postimplant and had 2 (1–5) hospital readmissions. Total support duration was 3,154 patient-days, with 2,413 as outpatient. Most frequent adverse events were device malfunction and arrhythmias. There was one death because of pump thrombosis and no bleeding or stroke events. Overall adverse event rate was 15.22 per 100 patient-months. Early experience suggests that children with CF-VADs can be safely discharged. Device malfunction and arrhythmia were the most common adverse events but were recognized quickly with structured outpatient surveillance.

Successful bridge to transplant with a continuous flow ventricular assist device in a single ventricle patient with an aortopulmonary shunt.

Ventricular assist devices are frequently used to bridge pediatric patients to cardiac transplantation; however, experience in single ventricle patients with aortopulmonary shunts remains limited. This case report addresses the challenge of balancing pulmonary and systemic circulation with a focus on the role of continuous versus pulsatile ventricular assist device support.

HLA desensitization with bortezomib in a highly sensitized pediatric patient

The proteasome inhibitor bortezomib has been used with variable success in the treatment of AMR following heart transplant. There is limited experience with this agent as a pretransplant desensitizing therapy. We report a case of successful HLA desensitization with a bortezomib‐based protocol prior to successful heart transplantation. A nine‐yr‐old boy with dilated cardiomyopathy, not initially sensitized to HLA (cPRA of zero), required three days of ECMO, followed by implantation of a Heartmate II LVAD. Within six wk, the patient developed de novo class I IgG and C1q complement‐fixing HLA antibodies with a cPRA of 100%. Two doses of IVIG (2 g/kg) failed to reduce antibody levels, although two courses of a novel desensitization protocol consisting of rituximab (375 mg/m2), bortezomib (1.3 mg/m2 × 5 doses), and plasmapheresis reduced his cPRA to 0% and 87% by the C1q and IgG assays, respectively. He underwent heart transplantation nearly two months later. The patient is now >one yr post‐transplant, is free of both AMR and ACR, and has no detectable donor‐specific antibodies by IgG or C1q. Proteasome inhibition with bortezomib and plasmapheresis may be an effective therapy for HLA desensitization pretransplant.

A novel pediatric treatment intensity score: development and feasibility in heart failure patients with ventricular assist devices

BACKGROUND The evolution of pharmacologic therapies and mechanical support including ventricular assist devices (VADs) has broadened the scope of care available to children with advanced heart failure. At the present time, there are only limited means of quantifying disease severity or the concomitant morbidity for this population. This study describes the development of a novel pediatric treatment intensity score (TIS), designed to quantify the burden of illness and clinical trajectory in children on VAD support. METHODS There were 5 clinical domains assessed: nutrition, respiratory support, activity level, cardiovascular medications, and care environment. A scale was developed through expert consensus. Higher scores indicate greater morbidity as reflected by intensity of medical management. To evaluate feasibility and face validity, the TIS was applied retrospectively to a subset of pediatric inpatients with VADs. The Bland-Altman method was used to assess limits of agreement. RESULTS The study comprised 39 patients with 42 implantations. Bland-Altman interobserver and intraobserver comparisons showed good agreement (mean differences in scores of 0.02, limits of agreement ±0.12). Trends in TIS were concordant with the overall clinical impression of improvement. Scores remained ≥0.6 preceding VAD implantation and peaked at 0.71 3 days after VAD implantation. CONCLUSIONS We describe a pediatric VAD scoring tool, to assess global patient morbidity and clinical recovery. We demonstrate feasibility of using this TIS in a test population of inpatients on VAD support.

Electrocardiographic repolarization abnormalities and increased risk of life-threatening arrhythmias in children with dilated cardiomyopathy

BACKGROUND Life-threatening arrhythmia events (LTEs) occur in ~5% of children with dilated cardiomyopathy (DCM). While prolonged QRS duration has been shown to be associated with LTEs, electrocardiographic (ECG) repolarization findings have not been examined. OBJECTIVE We sought to determine the associations between ECG repolarization abnormalities and LTEs in children with DCM. METHODS A single-center retrospective review of children with DCM was performed. LTEs were defined as documented ventricular tachycardia or fibrillation requiring medical intervention. Three pediatric cardiologists, blinded to clinical events, evaluated ECGs obtained at the time of initial referral. Kaplan-Meier survival and Cox proportional hazards analyses were used to evaluate time to LTEs. RESULTS A total of 137 patients (mean age 7.8 ± 6.7 years; 75(55%) male patients) with DCM (mean ejection fraction 35% ± 16%) were included; 67 patients (49%) had a corrected JT (JTc) interval of ≥340 ms, 72 (53%) had a corrected QT (QTc) interval of ≥450 ms, and 41 (30%) had abnormal T waves. LTEs occurred in 15 patients at a median of 12 months (interquartile range 3-36 months) after the initial ECG. Patients with LTEs had a longer JTc interval (371 ± 77 ms vs 342 ± 41 ms; P = .02) and a longer QTc interval (488 ± 96 ms vs 453 ± 44 ms; P = .01). In survival analysis, a JTc interval of ≥390 ms (hazard ratio [HR] 4.07; 95% confidence interval [CI] 1.12-14.83; P = .03), a QTc interval of ≥510 ms (HR 6.95; 95% CI 1.53-31.49; P = .01), abnormal T-wave inversion (HR 11.62; 95% CI 2.75-49.00; P = .001), and ST-segment depression (HR 6.91; 95% CI 1.25-38.27; P = .03) were associated with an increased risk of LTEs, even after adjusting for QRS duration and amiodarone use. CONCLUSION Repolarization abnormalities are common in children with DCM. Certain ECG repolarization abnormalities, such as significantly prolonged JTc and QTc intervals, may be useful in identifying patients at risk of LTEs.

Quality of life and metrics of achievement in long‐term adult survivors of pediatric heart transplant

Many children who undergo heart transplantation will survive into adulthood. We sought to examine the QOL and capacity for achievement in long‐term adult survivors of pediatric heart transplantation. Adults >18 yr of age who received transplants as children (≤18 yr old) and had survived for at least 10 yr post‐transplant completed two self‐report questionnaires: (i) Ferrans & Powers QLI, in which life satisfaction is reported as an overall score and in four subscale domains and is then indexed from 0 (very dissatisfied) to 1 (very satisfied); and (ii) a “Metrics of Life Achievement” questionnaire regarding income, education, relationships, housing status, and access to health care. A total of 20 subjects completed the survey. The overall mean QLI score was 0.77 ± 0.16. Subjects were most satisfied in the family domain (0.84 ± 0.21) and least satisfied in the psychological/spiritual domain (0.7 ± 0.28). Satisfaction in the domains of health/functioning and socioeconomic were intermediate at 0.78 and 0.76, respectively. Most respondents had graduated from high school, reported a median annual income >

Impact of ventricular assist device placement on longitudinal renal function in children with end-stage heart failure

50 000/yr, and lived independently. Adult survivors of pediatric heart transplant report a good QOL and demonstrate the ability to obtain an education, work, and live independently.

Feasibility of neonatal pulse wave velocity and association with maternal hemoglobin A1c.

BACKGROUND Although ventricular assist devices (VADs) restore hemodynamics in those with heart failure, reversibility of end-organ dysfunction with VAD support is not well characterized. Renal function often improves in adults after VAD placement, but this has not been comprehensively explored in children. METHODS Sixty-three children on VAD support were studied. Acute kidney injury (AKI) was defined by Kidney Disease: Improving Global Outcomes criteria. Estimated glomerular filtration rate (eGFR) was determined by the Schwartz method. Generalized linear mixed-effects models compared the pre-VAD and post-VAD eGFR for the cohort and sub-groups with and without pre-VAD renal dysfunction (pre-VAD eGFR < 90 ml/min/1.73 m(2)). RESULTS The pre-VAD eGFR across the cohort was 84.0 ml/min/1.73 m(2) (interquartile range [IQR] 62.3-122.7), and 55.6% (34 of 63) had pre-VAD renal dysfunction. AKI affected 60.3% (38 of 63), with similar rates in those with and without pre-existing renal dysfunction. Within the cohort, the nadir eGFR occurred 1 day post-operatively (62.9 ml/min/1.73 m(2); IQR, 51.2-88.9 ml/min/1.73 m(2); p < 0.001). By Day 5, however, the eGFR exceeded the baseline (99.0 ml/min/1.73 m(2); IQR, 59.3-146.7 ml/min/1.73 m(2); p = 0.03) and remained significantly higher through the first post-operative week. After adjusting for age, gender, and AKI, the eGFR continued to increase throughout the entire 180-day study period (β = 0.0025; 95% confidence interval, 0.0015-0.0036; p < 0.001). Patients with pre-VAD renal dysfunction experienced the greatest improvement in the eGFR (β = 0.0051 vs β = 0.0013, p < 0.001). CONCLUSIONS Renal dysfunction is prevalent in children with heart failure undergoing VAD placement. Although peri-operative AKI is common, renal function improves substantially in the first post-operative week and for months thereafter. This is particularly pronounced in those with pre-VAD renal impairment, suggesting that VADs may facilitate recovery and maintenance of kidney function in children with advanced heart failure.

Rehospitalization after pediatric heart transplantation: Incidence, indications, and outcomes.

Background: Use of non-invasive peripheral arterial tonometry to assess arterial stiffness has not been studied in neonates. Perinatal factors impact childhood vascular health, but the effect in neonates remains to be examined. Objectives: To examine the feasibility of pulse wave velocity (PWV) among healthy term neonates, and to evaluate the effects of perinatal factors on neonatal PWV. Methods: Pregnant women with singleton gestation presenting for routine care were enrolled. Postnatally, PWV measurements of their neonates were obtained using an arterial tonometer. A variability index was calculated for each PWV measurement. Intra- and inter-observer reproducibility were illustrated with Bland-Altman plots. Medical records were reviewed. Relationships between neonatal PWV and perinatal factors were examined. Results: PWV measurements were attempted in 76 neonates and successfully obtained in 67 (88%). Using PWV measurements with a variability index ≤0.25 (48 neonates), the intra-class coefficient was 0.69. The mean differences (limits of agreement) for intra- and inter-rater reproducibility were 0.02 (-3.64 to 3.60) and 0.34 (-2.23 to 2.39), respectively. Median neonatal PWV was 2.80 m/s (range 0.60-8.40). Neonates of mothers with HgbA1c ≥6% had significantly higher PWV than neonates of mothers with HgbA1c <6% (4.12 m/s, 95% CI 3.22-5.02, vs. 2.78 m/s, 95% CI 2.28-3.28, p = 0.02). Conclusions: Neonatal PWV using peripheral arterial tonometry is feasible and reproducible when using measurements with a variability index ≤0.25. Neonates of mothers with increased HgbA1c had higher PWV, suggesting an effect of maternal hyperglycemia on neonatal vasculature. The long-term implications of this finding warrant further investigation.