Utility of apical four-chamber longitudinal strain in the assessment of childhood cancer survivors: A multicenter study.

BACKGROUND: A previous multicenter study showed that longitudinal changes in standard cardiac functional parameters were associated with the development of cardiomyopathy in childhood cancer survivors (CCS). Evaluation of the relationship between global longitudinal strain (GLS) changes and cardiomyopathy risk was limited, largely due to lack of quality apical 2- and 3-chamber views in addition to 4-chamber view. We sought to determine whether apical 4-chamber longitudinal strain (A4LS) alone can serve as a suitable surrogate for GLS in this population. METHODS: A4LS and GLS were measured in echocardiograms with acceptable apical 2-, 3-, and 4-chamber views. Correlation was evaluated using Pearson and Spearman coefficients, and agreement was evaluated with Bland-Altman plots. The ability of A4LS to identify normal and abnormal values compared to GLS as the reference was evaluated. RESULTS: Among a total of 632 reviewed echocardiograms, we identified 130 echocardiograms from 56 patients with adequate views (38% female; mean age at cancer diagnosis 8.3 years; mean follow-up 9.4 years). Correlation coefficients between A4LS and GLS were .89 (Pearson) and .85 (Spearman), with Bland-Altman plot of GLS-A4LS showing a mean difference of -.71 ± 1.8. Compared with GLS as the gold standard, A4LS had a sensitivity of 86% (95% CI 79%-93%) and specificity of 82% (69%-95%) when using normal range cutoffs and 90% (82%-97%) and 70% (58%-81%) when using ±2 standard deviations. CONCLUSION: A4LS performs well when compared with GLS in this population. Given the more recent adoption of apical 2- and 3-chamber views in most pediatric echocardiography laboratories, A4LS is a reasonable stand-alone measurement in retrospective analyses of older study cohorts and echocardiogram biorepositories.

Contemporary transesophageal echocardiography practice patterns among paediatric cardiology centres in the United States and Canada.

OBJECTIVE: To characterise transesophageal echocardiography practice patterns among paediatric cardiac surgical centres in the United States and Canada. METHODS: A 42-question survey was sent to 80 echocardiography laboratory directors at paediatric cardiology centres with surgical programmes in the United States and Canada. Question domains included transesophageal echocardiography centre characteristics, performance and reporting, equipment use, trainee participation, and quality assurance. RESULTS: Fifty of the 80 centres (62.5%) responded to the survey. Most settings were academic (86.0%) with 42.0% of centres performing > 350 surgical cases/year. The median number of transesophageal echocardiograms performed/cardiologist/year was 50 (26, 73). Pre-operative transesophageal echocardiography was performed in most surgical cases by 91.7% of centres. Transesophageal echocardiography was always performed by most centres following Norwood, Glenn, and Fontan procedures and by < 10% of centres following coarctation repair. Many centres with a written guideline allowed transesophageal echocardiography transducer use at weights below manufacturer recommendations (50.0 and 61.1% for neonatal and paediatric transducers, respectively). Most centres (36/37, 97.3%) with categorical fellowships had rotations which included transesophageal echocardiography participation. Large surgical centres (>350 cases/year) had higher median number of transesophageal echocardiograms/cardiologist/year (75.5 [53, 86] versus 35 [20, 52], p < 0.001) and more frequently used anaesthesia for diagnostic transesophageal echocardiography ≥ 67% of time (100.0 versus 62.1%, p = 0.001). CONCLUSIONS: There is significant variability in transesophageal echocardiography practice patterns and training requirements among paediatric cardiology centres in the United States and Canada. Findings may help inform programmatic decisions regarding transesophageal echocardiography expectations, performance and reporting, equipment use, trainee involvement, and quality assurance.

Challenges associated with retrospective analysis of left ventricular function using clinical echocardiograms from a multicenter research study.

BACKGROUND: Retrospective multicenter research using echocardiograms obtained for routine clinical care can be hampered by issues of individual center quality. We sought to evaluate imaging and patient characteristics associated with poorer quality of archived echocardiograms from a cohort of childhood cancer survivors. METHODS: A single blinded reviewer at a central core laboratory graded quality of clinical echocardiograms from five centers focusing on images to derive 2D and M-mode fractional shortening (FS), biplane Simpson's ejection fraction (EF), myocardial performance index (MPI), tissue Doppler imaging (TDI)-derived velocities, and global longitudinal strain (GLS). RESULTS: Of 535 studies analyzed in 102 subjects from 2004 to 2017, all measures of cardiac function could be assessed in only 7%. While FS by 2D or M-mode, MPI, and septal E/E' could be measured in >80% studies, mitral E/E' was less consistent (69%), but better than EF (52%) and GLS (10%). 66% of studies had ≥1 issue, with technical issues (eg, lung artifact, poor endocardial definition) being the most common (33%). Lack of 2- and 3-chamber views was associated with the performing center. Patient age <5 years had a higher chance of apex cutoff in 4-chamber views compared with 16-35 years old. Overall, for any quality issue, earlier era of echo and center were the only significant risk factors. CONCLUSION: Assessment of cardiac function using pooled multicenter archived echocardiograms was significantly limited. Efforts to standardize clinical echocardiographic protocols to include apical 2- and 3-chamber views and TDI will improve the ability to quantitate LV function.

Prognostic significance of tissue Doppler imaging-derived myocardial performance index in pediatric patients with dilated cardiomyopathy.

TDI-MPI has been shown to predict cardiovascular mortality in adults; there are a paucity of data on its use in children. We sought to determine the prognostic significance of TDI-MPI at time of DCM diagnosis in children. Patients aged ≤18 years diagnosed with DCM were included along with age- and sex-matched controls. Echo at diagnosis was analyzed to obtain standard measures of LV function, PW-MPI, and septal and LV free wall TDI-MPI. Survival analysis was used to assess the time to composite outcome of death, VAD, or transplant, stratified by TDI-MPI z-score. The study included 79 patients with DCM and 79 controls. During a median follow-up of 182 days (IQR 41-815 days), 16 underwent VAD placement, 21 underwent cardiac transplant, 6 died, and 36 had event-free survival. The median septal TDI-MPI for cases was 0.70 for patients with DCM vs 0.45 for controls (P < .001). Those with septal TDI-MPI z-scores ≥2 develop events significantly earlier than those with z-score <2 (P = .014). In multivariable analysis, TDI-MPI z-score ≥2 was significantly associated with poor outcomes (HR 2.12, 95% CI 1.06-4.23). TDI-MPI can be reliably performed in pediatric patients with DCM. A TDI-MPI z-score ≥2 at diagnosis may be associated with earlier poor outcome. Further studies evaluating the use of TDI-MPI in longitudinal follow-up of patients with DCM may be helpful in refining its clinical use.

Exercise stress echocardiography: Impact on clinical decision-making in pediatric patients.

BACKGROUND: The role of exercise stress echocardiography (ESE) in the pediatric population is less well defined as compared to adults. We aimed to determine the utility and impact of ESE on clinical decision-making in pediatric patients. METHODS: We identified patients who underwent an ESE at our center from 2011 to 2015. Test indications were categorized into symptoms with exercise; sports/activity clearance; hypertrophic cardiomyopathy (HCM) or suspected HCM; coronary anomalies; or abnormal electrocardiogram (EKG). Change in clinical management was assessed by comparing pre- and post-test activity restrictions, which were categorized into unrestricted from exercise or activity; restricted from exercise or activity; and surgical referral. RESULTS: During the study period, 353 ESEs met inclusion criteria. Of all ESEs performed, 263 (75%) were normal. Clinical management changed as a result of ESE in 144 (40%). Of the abnormal ESEs, 44 were restricted from activity, including 25 (56.8%) restricted from competitive or varsity athletics, 14 (31.8%) restricted from recreational sports, and 5 (11.4%) restricted from all activity. Surgical referrals included valve repair/replacement in 7 (50%), ICD placement in 5 (35.8%), coronary re-implantation in 1 (7.1%), and atrial septal defect repair in 1 (7.1%). CONCLUSION: Exercise stress echocardiography provides the pediatric cardiologist with useful information that impacts management in a wide variety of cardiac disorders. Clinical management changed in nearly half the patients that were subjected to an ESE at our center. This supports the value of ESE for informing clinical decision-making. Future studies should aim to refine patient selection and examine its impact on patient outcomes.

Improving paediatric cardiologists' awareness about the needs of childhood cancer survivors: results of a single-centre directed educational initiative.

BACKGROUND: Cardiovascular disease is a leading cause of morbidity and mortality in childhood cancer survivors. Cardiologists must be aware of risk factors and long-term follow-up guidelines, which have historically been the purview of oncologists. Little is known about paediatric cardiologists' knowledge regarding the cardiotoxicity of cancer treatment and how to improve this knowledge. METHODS: A total of 58 paediatric cardiologists anonymously completed a 21-question, web-based survey focused on four cardio-oncology themes: cancer treatment-related risk factors (n = 6), patient-related risk factors (n = 6), recommended surveillance (n = 3), and cardiac-specific considerations (n = 6). Following the baseline survey, a multi-disciplinary team of paediatric cardiologists and cancer survivor providers developed an in-person and web-based educational intervention. A post-intervention survey was conducted 5 months later. RESULTS: The response rate was 41/58 (70.7%) pre-intervention and 30/58 (51.7%) post-intervention. On the baseline survey, the percentage of correct answers was 68.8 ± 10.3%, which improved to 79.2 ± 16.2% after the intervention (p = 0.009). The theme with the most profound knowledge deficit was surveillance; however, it also had the greatest improvement after the intervention (49.6 ± 26.7 versus 66.7 ± 27.7% correct, p = 0.025). Individual questions with the largest per cent improvement pertained to risk of cardiac dysfunction with time since treatment (52.4 versus 93.1%, p = 0.002) and the role of dexrazoxane (48.8 versus 82.8%, p = 0.020). CONCLUSION: Specific knowledge deficits about the care of paediatric cancer survivors were identified amongst cardiologists using a web-based survey. Knowledge of surveillance was initially lowest but improved the most after an educational intervention. This highlights the need for cardio-oncology-based educational initiatives among paediatric cardiologists.

The Pediatric Heart Network Scholar Award programme: a unique mentored award embedded within a multicentre network.

BACKGROUND: The Pediatric Heart Network designed a career development award to train the next generation of clinician scientists in paediatric-cardiology-related research, a historically underfunded area. We sought to identify the strengths/weaknesses of the programme and describe the scholars' academic achievements and the network's return on investment. METHODS: Survey questions designed to evaluate the programme were sent to applicants - 13 funded and 19 unfunded applicants - and 20 mentors and/or principal investigators. Response distributions were calculated. χ2 tests of association assessed differences in ratings of the application/selection processes among funded scholars, unfunded applicants, and mentors/principal investigators. Scholars reported post-funding academic achievements. RESULTS: Survey response rates were 88% for applicants and 100% for mentor/principal investigators. Clarity and fairness of the review were rated as "clear/fair" or "very clear/very fair" by 98% of respondents, but the responses varied among funded scholars, unfunded applicants, and mentors/principal investigators (clarity χ2=10.85, p=0.03; fairness χ2=16.97, p=0.002). Nearly half of the unfunded applicants rated feedback as "not useful" (47%). "Expanding their collaborative network" and "increasing publication potential" were the highest-rated benefits for scholars. Mentors/principal investigators found the programme "very" valuable for the scholars (100%) and the network (75%). The 13 scholars were first/senior authors for 97 abstracts and 109 manuscripts, served on 22 Pediatric Heart Network committees, and were awarded $9,673,660 in subsequent extramural funding for a return of ~$10 for every scholar dollar spent. CONCLUSIONS: Overall, patient satisfaction with the Scholar Award was high and scholars met many academic markers of success. Despite this, programme challenges were identified and improvement strategies were developed.

Yield of screening echocardiograms during pediatric follow-up in survivors treated with anthracyclines and cardiotoxic radiation.

BACKGROUND: Guidelines published by the Children's Oncology Group recommend screening echocardiograms for childhood cancer survivors exposed to anthracyclines and/or cardiotoxic radiation. This study aims to assess risk factors for cardiac late effects while evaluating the overall yield of screening echocardiograms. PROCEDURE: Demographics, exposures, and echocardiogram results were abstracted from the medical records of survivors diagnosed at ≤ 21 years old and ≥ 2 years off therapy who were exposed to anthracyclines and/or potentially cardiotoxic radiotherapy. Descriptive statistics and logistic regressions were performed and the yield of screening echocardiograms was calculated. RESULTS: Of 853 patients, 1,728 screening echocardiograms were performed, and 37 patients had an abnormal echocardiogram (overall yield 2.1%). Yields were only somewhat higher in more frequently screened patients. Risk factors for an abnormal result included anthracycline dose of ≥300 mg/m2 (adjusted odds ratio [aOR] 3.1; 95% confidence interval [CI]: 1.3-7.2; P < 0.01) with a synergist relationship in patients who also received radiation doses ≥30 Gy (aOR 7.0; 95% CI: 1.6-31.9; P = 0.01), as well as autologous bone marrow transplant (OR 3.3; 95% CI: 1.3-8.5; P = 0.01). Sex, race, age at diagnosis, and cyclophosphamide exposure were not statistically significant risk factors, and no patient receiving <100 mg/m2 anthracycline dose without concomitant radiation had an abnormal echocardiogram. CONCLUSIONS: Dose-dependent and synergist anthracycline and cardiotoxic radiotherapy risks for developing cardiomyopathy were confirmed. However, previously identified risk factors including female sex, black race, and early age at diagnosis were not replicated in this cohort. The yields showed weak correlation across frequency categories. Echocardiographic screening recommendations for low-risk pediatric patients may warrant re-evaluation.

Tricuspid annular plane systolic excursion as a marker of right ventricular dysfunction in pediatric patients with dilated cardiomyopathy.

BACKGROUND: Right ventricular systolic dysfunction (RVSD) is a predictor of outcomes in dilated cardiomyopathy (DCM) in adults, but little is known in children. Tricuspid annular plane systolic excursion (TAPSE) has emerged as a reliable tool to assess RVSD. We sought to determine the prevalence and prognostic significance of RVSD using TAPSE in children with DCM. METHODS: The first echocardiogram at the time of diagnosis with DCM was analyzed to obtain left ventricular ejection fraction (LVEF) and 2D TAPSE. RVSD was defined as TAPSE age-based z-score ≤-2. The association of a composite primary endpoint including death, mechanical support, or transplantation with RVSD was analyzed using LVEF and TAPSE. RESULTS: Of the 96 patients, RVSD was noted in 84 (88%). During a median follow-up of 17.5 months (IQR 1.4, 76.2), the primary endpoints were reached in 59%. There was a lower LVEF in patients with RVSD (P=.016). Moderate or severe RVSD showed a significant association with the composite primary endpoint (unadjusted OR 2.7 [95% CI: 1.15-6.33], P=.023). Kaplan-Meier analysis showed that the event-free survival was significantly lower in patients with LVEF ≤30% and TAPSE z-score ≤-4. CONCLUSION: Children with DCM have a high prevalence of RVSD based on reduced TAPSE, and those with moderate or severe RVSD have worse clinical outcomes.

Cardio-oncology Related to Heart Failure: Pediatric Considerations for Cardiac Dysfunction.

Although tremendous advances in pediatric cancer treatment have improved the survival of many children, these patients remain at increased risk of early morbidity and mortality with cardiovascular disease as a leading cause of death. Heightened awareness in providers with increased surveillance and improvement in cardiovascular imaging modalities have led to earlier detection of cardiac dysfunction, but the outcomes remain poor once this has dysfunction developed. A great deal of work remains to be done to refine screening and identify high-risk patients more precisely, and to develop more evidence-based strategies for effective primary and secondary cardioprotection and treatment.

Pediatric quality of life in long-term survivors of childhood cancer treated with anthracyclines.

BACKGROUND: Anthracyclines are a common class of drugs used to treat pediatric cancer. While much attention is given to their cardiotoxicity, little is known about the relationship between the use of anthracyclines and health-related quality-of-life (HRQoL) outcomes. This study examines the association of anthracycline cardiotoxicity risk status and Pediatric Quality-of-Life (PedsQL) InventoryTM scores in childhood cancer METHODS: Pediatric cancer survivors aged 8-21 who were at least 5 years posttreatment were recruited from a Cancer Survivor Clinic. Participants completed the PedsQL 4.0 Generic Core Scales and a health behavior survey. Linear regression was used to evaluate the association between PedsQL scores and anthracycline cardiotoxicity risk status and to assess whether self-reported physical activity modified the association. RESULTS: Eighty survivors participated and were characterized by cardiotoxicity risk status (high: 12; moderate: 23, low: 24, no risk: 21) as defined by the Children's Oncology Group (COG). Measures in all PedsQL domains tended to be slightly lower for survivors exposed to anthracyclines as compared to the unexposed. The largest difference in unadjusted mean scores was for social functioning (96.0% for unexposed vs. 91.3% for exposed, P = 0.0068). There was also an inverse dose-response relation between adjusted PedsQL scores and increasing anthracycline cardiotoxicity risk; this association was not modified by physical activity level. CONCLUSION: These data indicate that regular psychosocial assessments, such as those currently recommended by the COG, may be especially important for survivors treated with anthracyclines.

Quantitative Assessment of Ventricular Septal Contour for Estimation of Right Ventricular Pressure.

BACKGROUND: Qualitative assessment of ventricular septal flattening is commonly used in pediatric patients with pulmonary hypertension (PH) who lack adequate tricuspid regurgitation (TR) Doppler signal. We sought to determine the relation between quantitative measures of septal flattening including the eccentricity index (EIs) and a novel marker, the septal flattening angle (SFA) with right ventricular systolic pressure (RVSP). METHODS: Subjects (≤18 years) with an anatomically normal heart, an adequate TR signal to obtain a peak velocity, and a simultaneous systemic systolic blood pressure (SBP) was included. RVSP was derived using TR gradient. Eccentricity index (EIs) and the SFA in systole were measured offline and correlated with RVSP/SBP. RESULTS: Of the 108 subjects, RVSP/SBP was < 50% in 77 and ≥ 50% in 31. In those with RVSP/SBP ≥50%, the median SFA was significantly lower (7.4° vs. 22°, p < 0.0001), and the median EIs was higher (1.61 vs. 1.07, p < 0.0001). SFA and EIs had a significant correlation with RVSP/SBP (rs = -0.70 and 0.61, respectively). Area under the curve was higher for SFA compared to EIs (0.92 and 0.85, respectively). The sensitivity and specificity of SFA for predicting an RVSP/SBP ≥ 50% using a cut point of 16° was 84% and 95% and for an EIs cut point of 1.35 was 74.2% and 96.1%, respectively. CONCLUSION: Septal flattening angle and EIs are quantitative measures of ventricular septal flattening that correlate well with RVSP/SBP and should be considered more routinely in clinical practice, especially in patients with inadequate TR Doppler signal.

Importance of Relationship between Ductus and Isthmus in Fetal Diagnosis of Coarctation of Aorta.

BACKGROUND: The prenatal diagnosis of coarctation of aorta (CoA) can prove problematic, with relatively high false-positive and false-negative rates. This significantly impacts both prenatal counseling and postnatal management. We sought to evaluate a variety of prenatal echo indices to determine which would best predict neonatal CoA. METHODS: Fetal echocardiograms of those with prenatal diagnosis of COA were analyzed for the following: diameter of cardiac valves, ascending aorta, distal transverse arch, aortic isthmus, and ductus; right (RV) and left ventricular (LV) length and end-diastolic area and isthmus-ductal angle (IDA). Ratios of RV: LV area, aortic: pulmonary valve diameter, mitral: tricuspid valve ratio (MV:TV ratio), and isthmus: ductal diameter (IDD) were calculated. These measures were compared between those with CoA after birth (CoA group) and those without (no CoA group). RESULTS: Of the 62 subjects, 27 were in CoA and 35 in no CoA group. CoA group had a significantly smaller mitral valve, MV:TV ratio, IDD, and IDA compared to no CoA group. The ROC curves for each of these significant measures showed that mitral valve, IDD, and IDA had an AUC of 0.72, 0.80, and 0.83, respectively. Multiple variable model using at least two of these measures had 85% sensitivity and 60% specificity. CONCLUSIONS: A smaller mitral valve, MV:TV ratio, IDD, and IDA are associated with development of neonatal coarctation. In cases with suspected prenatal diagnosis of CoA, careful evaluation of the relation between the isthmus and the ductus arteriosus using IDD and IDA may enhance the diagnostic accuracy of fetal echocardiograms.

Assessing anthracycline-treated childhood cancer survivors with advanced stress echocardiography.

BACKGROUND: Surveillance for anthracycline cardiotoxicity in cancer survivors typically utilizes resting M-mode and two-dimensional echocardiography, which are insensitive to detection of subtle myocardial changes. We examined childhood cancer survivors treated with anthracyclines during exercise using various echocardiography techniques to investigate if these tools can better detect subclinical cardiac dysfunction. PROCEDURE: We recruited asymptomatic survivors at least five years post treatment. Echocardiography was performed at rest and at termination of exercise utilizing tissue Doppler techniques and strain rate imaging. RESULTS: Eighty participants were characterized by cardiotoxicity risk status (high [12], moderate [23], low [24], no risk [21]) as defined by the Children's Oncology Group Long Term Follow-Up Guidelines v3.0. The high-risk group had a higher resting heart rate than controls (100 vs. 88 bpm [P for trend = 0.049]). Peak aerobic capacity in all groups was similar. Compared to controls at rest, the high-risk group had evidence of diastolic dysfunction with lower E/A ratios (1.4 vs. 2.0, P = 0.008) and higher septal early diastolic velocities (E/E') of 11.7 versus 9.9 (P = 0.165). With exercise, this difference resolved and myocardial contractile reserve was preserved. CONCLUSIONS: Asymptomatic, pediatric cancer survivors at high-risk for anthracycline cardiotoxicity have some evidence of diastolic filling abnormalities at rest. With exercise, they augment their systolic and diastolic function to achieve normal maximal aerobic capacity suggesting they are able to compensate for mild cardiac dysfunction in the early years after exposure. Additionally, findings suggest that routine exercise echocardiography may not be a useful surveillance tool to assess anthracycline cardiotoxicity.

A Multicenter Analysis of Abnormal Chromosomal Microarray Findings in Congenital Heart Disease.

Background Chromosomal microarray analysis (CMA) provides an opportunity to understand genetic causes of congenital heart disease (CHD). The methods for describing cardiac phenotypes in patients with CMA abnormalities have been inconsistent, which may complicate clinical interpretation of abnormal testing results and hinder a more complete understanding of genotype-phenotype relationships. Methods and Results Patients with CHD and abnormal clinical CMA were accrued from 9 pediatric cardiac centers. Highly detailed cardiac phenotypes were systematically classified and analyzed for their association with CMA abnormality. Hierarchical classification of each patient into 1 CHD category facilitated broad analyses. Inclusive classification allowing multiple CHD types per patient provided sensitive descriptions. In 1363 registry patients, 28% had genomic disorders with well-recognized CHD association, 67% had clinically reported copy number variants (CNVs) with rare or no prior CHD association, and 5% had regions of homozygosity without CNV. Hierarchical classification identified expected CHD categories in genomic disorders, as well as uncharacteristic CHDs. Inclusive phenotyping provided sensitive descriptions of patients with multiple CHD types, which occurred commonly. Among CNVs with rare or no prior CHD association, submicroscopic CNVs were enriched for more complex types of CHD compared with large CNVs. The submicroscopic CNVs that contained a curated CHD gene were enriched for left ventricular obstruction or septal defects, whereas CNVs containing a single gene were enriched for conotruncal defects. Neuronal-related pathways were over-represented in single-gene CNVs, including top candidate causative genes NRXN3, ADCY2, and HCN1. Conclusions Intensive cardiac phenotyping in multisite registry data identifies genotype-phenotype associations in CHD patients with abnormal CMA.

Rationale and design of the Children's Oncology Group study AAML1831 integrated cardiac substudies in pediatric acute myeloid leukemia therapy.

Background: Pediatric acute myeloid leukemia (AML) therapy is associated with substantial short- and long-term treatment-related cardiotoxicity mainly due to high-dose anthracycline exposure. Early left ventricular systolic dysfunction (LVSD) compromises anthracycline delivery and is associated with inferior event-free and overall survival in de novo pediatric AML. Thus, effective cardioprotective strategies and cardiotoxicity risk predictors are critical to optimize cancer therapy delivery and enable early interventions to prevent progressive LVSD. While dexrazoxane-based cardioprotection reduces short-term cardiotoxicity without compromising cancer survival, liposomal anthracycline formulations have the potential to mitigate cardiotoxicity while improving antitumor efficacy. This overview summarizes the rationale and methodology of cardiac substudies within AAML1831, a randomized Children's Oncology Group Phase 3 study of CPX-351, a liposomal formulation of daunorubicin and cytarabine, in comparison with standard daunorubicin/cytarabine with dexrazoxane in the treatment of de novo pediatric AML. Methods/design: Children (age <22 years) with newly diagnosed AML were enrolled and randomized to CPX-351-containing induction 1 and 2 (Arm A) or standard daunorubicin and dexrazoxane-containing induction (Arm B). Embedded cardiac correlative studies aim to compare the efficacy of this liposomal anthracycline formulation to dexrazoxane for primary prevention of cardiotoxicity by detailed core lab analysis of standardized echocardiograms and serial cardiac biomarkers throughout AML therapy and in follow-up. In addition, AAML1831 will assess the ability of early changes in sensitive echo indices (e.g., global longitudinal strain) and cardiac biomarkers (e.g., troponin and natriuretic peptides) to predict subsequent LVSD. Finally, AAML1831 establishes expert consensus-based strategies in cardiac monitoring and anthracycline dose modification to balance the potentially competing priorities of cardiotoxicity reduction with optimal leukemia therapy. Discussion: This study will inform diagnostic, prognostic, preventative, and treatment strategies regarding cardiotoxicity during pediatric AML therapy. Together, these measures have the potential to improve leukemia-free and overall survival and long-term cardiovascular health in children with AML. Clinical trial registration: https://clinicaltrials.gov/, identifier NCT04293562.

Enalapril in infants with single ventricle: results of a multicenter randomized trial.

BACKGROUND: Angiotensin-converting enzyme inhibitor therapy improves clinical outcome and ventricular function in adults with heart failure. Infants with single-ventricle physiology have poor growth and are at risk for abnormalities in ventricular systolic and diastolic function. The ability of angiotensin-converting enzyme inhibitor therapy to preserve ventricular function and improve somatic growth and outcomes in these infants is unknown. METHODS AND RESULTS: The Pediatric Heart Network conducted a double-blind trial involving 230 infants with single-ventricle physiology randomized to receive enalapril (target dose 0.4 mg . kg(-1) . d(-1)) or placebo who were followed up until 14 months of age. The primary end point was weight-for-age z score at 14 months. The primary analysis was intention to treat. A total of 185 infants completed the study. There were 24 and 21 withdrawals or deaths in the enalapril and placebo groups, respectively (P=0.74). Weight-for-age z score was not different between the enalapril and placebo groups (mean+/-SE -0.62+/-0.13 versus -0.42+/-0.13, P=0.28). There were no significant group differences in height-for-age z score, Ross heart failure class, brain natriuretic peptide concentration, Bayley scores of infant development, or ventricular ejection fraction. The incidence of death or transplantation was 13% and did not differ between groups. Serious adverse events occurred in 88 patients in the enalapril group and 87 in the placebo group. CONCLUSIONS: Administration of enalapril to infants with single-ventricle physiology in the first year of life did not improve somatic growth, ventricular function, or heart failure severity. The results of this randomized trial do not support the routine use of enalapril in this population.

A juvenile murine heart failure model of pressure overload.

Persistent pressure overload can cause cardiac hypertrophy and progressive heart failure (HF). The authors developed a pressure-overload HF model of juvenile mice to study the cardiac response to pressure overload that may be applicable to clinical processes in children. Severe thoracic aortic banding (sTAB) was performed using a 28-gauge needle for 40 juvenile (age, 3 weeks) and 47 adult (age, 6 weeks) C57BL/6 male mice. To monitor the structural and functional changes, M-mode echocardiography was performed for conscious mice that had undergone sTAB and sham operation. Cardiac hypertrophy, dilation, and HF occurred in both juvenile and adult mice after sTAB. Compared with adults, juvenile HF is characterized by greater impairment of ventricular contractility and less hypertrophy. In addition, juvenile mice had significantly higher rates of survival than adult mice during the early postoperative weeks. Consistent with clinical HF seen in children, juvenile banded mice demonstrated a lower growth rate than either adult banded mice or juvenile control mice that had sham operations. The authors first developed a juvenile murine model of pressure-overload HF. Learning the unique characteristics of pressure-overload HF in juveniles should aid in understanding age-specific pathologic changes for HF development in children.

Right ventricular function in adult patients with Eisenmenger physiology: insights from quantitative echocardiography.

BACKGROUND: The favorable outcomes of Eisenmenger syndrome (ES) relative to other forms of pulmonary arterial hypertension (PAH) have been partially attributed to a unique adaptation of the right ventricle (RV). However, conventional measures of RV function may not adequately express this adaptation. METHODS: We studied 23 patients with ES (age 43 ± 17 years, 16 women, pulmonary artery systolic pressure [PASP] 93 ± 26 mmHg), 25 patients with PAH (age 44 ± 13 years, 17 women, PASP 92 ± 19 mmHg), and 25 subjects without known structural disease (age 45 ± 16 years, 17 women). We evaluated long- and short-axis function of the RV with two-dimensional strain and anatomical M-mode echocardiography, respectively. RESULTS: Long-axis function of the RV was comparable between patients with ES and PAH although depressed relative to controls (global strain, -15.6 ± 4.7, -14.9 ± 4.3, and -22.4 ± 2.8%, respectively, P < 0.001; global RV systolic strain rate, -0.77 ± 0.26, -0.84 ± 0.24, and -1.11 ± 0.21 1/sec, respectively, P < 0.001). However, short-axis RV function was significantly better in patients with ES versus those with PAH and preserved relative to controls (RV fractional shortening by anatomical M-mode, median [interquartile range], 21%[14-33%], 14%[10-16%], and 26%[22-36%], respectively, P = 0.002 for ES vs. PAH, P = 0.09 for ES vs. controls). This differential was not reflected in conventional measures of RV function (fractional area change, 32 ± 10 vs. 29 ± 8% in ES and PAH, respectively, P = 0.26). CONCLUSION: In patients with ES, the RV is characterized by preserved short-axis function, despite a depressed long-axis function. Thus, conventional assessment of RV function might not be suitable for patients with ES.

Factors Influencing Temporal Trends in Pediatric Inpatient Imaging Utilization.

BACKGROUND: Concern exists over exponential growth in cardiac imaging in adults, but there is paucity of such data for cardiac imaging trends in pediatric patients. The aims of this study were to determine temporal trends in the use of noninvasive cardiac imaging and compare these with trends in the use of noncardiac imaging and to identify factors influencing those trends using the Pediatric Health Information Service database. METHODS: Pediatric inpatient encounter data from January 2004 to December 2017 at 35 pediatric hospitals were extracted from the Pediatric Health Information Service database. Temporal imaging utilization trends in cardiac and noncardiac ultrasound or echocardiography, magnetic resonance imaging (MRI), and computed tomography (CT) were assessed using linear mixed-effects models. Models were adjusted for case-mix index, complex chronic conditions, patient age, length of stay, payer source, and cardiac surgical volume. RESULTS: A total of 5,869,335 encounters over 14 years were analyzed (median encounters per center per year, 11,411; median patient age, 4 years; median length of stay, 3 days). From 2004 to 2017, the rates of pediatric inpatient cardiac and noncardiac ultrasound and MRI increased, whereas the rate of noncardiac CT decreased. Cardiac CT use increased beginning in 2014 (+0.264 cardiac CT encounters per 1,000 encounters per year), surpassing the rate of rise of cardiac MRI. Case-mix index, cardiac surgical volume, and payer source affected the largest number of imaging trends. CONCLUSIONS: Among pediatric inpatients, utilization of cardiac and noncardiac ultrasound and MRI has steadily increased. Noncardiac CT use declined and cardiac CT use increased after 2014. Factors influencing imaging trends include case-mix index, cardiac surgical volume, and payer source. This study lays a foundation for investigations of imaging-related resource utilization and outcomes among pediatric inpatients.