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.

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.

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.

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.

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.

Longitudinal Changes in Echocardiographic Parameters of Cardiac Function in Pediatric Cancer Survivors.

BACKGROUND: Childhood cancer survivors undergo serial echocardiograms to screen for cardiotoxicity. It is not clear whether small longitudinal changes in functional or structural parameters over time have clinical significance. OBJECTIVES: To assess the timing of changes in serial echocardiographic parameters in pediatric age childhood cancer survivors and to evaluate their associations with cardiomyopathy development. METHODS: We performed a multi-center retrospective case-control study of ≥1-year survivors following the end of cancer therapy. Cardiomyopathy cases (fractional shortening (FS) ≤28% or ejection fraction (EF) ≤50% on ≥2 occasions) were matched to controls (FS ≥30%, EF ≥55%, not on cardiac medications) by cumulative anthracycline and chest radiation dose, follow-up duration, and age at diagnosis. Digitally archived clinical surveillance echocardiograms were quantified in a central core lab, blinded to patient characteristics. Using mixed models with interaction terms between time and case status, we estimated the least square mean differences of 2D, M-mode, pulsed wave Doppler and tissue Doppler imaging derived parameters across time between cases and controls. RESULTS: We identified 50 matched case-control pairs from 5 centers. Analysis of 412 echocardiograms (cases, n=181; controls, n=231) determined that indices of LV systolic function (FS, biplane EF), diastolic function (mitral E/A ratio), and LV size (end diastolic dimension z-scores) were significantly different between cases and controls, even four years prior to the development of cardiomyopathy. CONCLUSIONS: Longitudinal changes in cardiac functional parameters can occur relatively early in pediatric age childhood cancer survivors and are associated with the development of cardiomyopathy.

Traditional Cardiovascular Risk Factors and Individual Prediction of Cardiovascular Events in Childhood Cancer Survivors.

BACKGROUND: Childhood cancer survivors have an increased risk of heart failure, ischemic heart disease, and stroke. They may benefit from prediction models that account for cardiotoxic cancer treatment exposures combined with information on traditional cardiovascular risk factors such as hypertension, dyslipidemia, and diabetes. METHODS: Childhood Cancer Survivor Study participants (n = 22 643) were followed through age 50 years for incident heart failure, ischemic heart disease, and stroke. Siblings (n = 5056) served as a comparator. Participants were assessed longitudinally for hypertension, dyslipidemia, and diabetes based on self-reported prescription medication use. Half the cohort was used for discovery; the remainder for replication. Models for each outcome were created for survivors ages 20, 25, 30, and 35 years at the time of prediction (n = 12 models). RESULTS: For discovery, risk scores based on demographic, cancer treatment, hypertension, dyslipidemia, and diabetes information achieved areas under the receiver operating characteristic curve and concordance statistics 0.70 or greater in 9 and 10 of the 12 models, respectively. For replication, achieved areas under the receiver operating characteristic curve and concordance statistics 0.70 or greater were observed in 7 and 9 of the models, respectively. Across outcomes, the most influential exposures were anthracycline chemotherapy, radiotherapy, diabetes, and hypertension. Survivors were then assigned to statistically distinct risk groups corresponding to cumulative incidences at age 50 years of each target outcome of less than 3% (moderate-risk) or approximately 10% or greater (high-risk). Cumulative incidence of all outcomes was 1% or less among siblings. CONCLUSIONS: Traditional cardiovascular risk factors remain important for predicting risk of cardiovascular disease among adult-age survivors of childhood cancer. These prediction models provide a framework on which to base future surveillance strategies and interventions.

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.

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.

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.

The landscape of cardiovascular care in pediatric cancer patients and survivors: a survey by the ACC Pediatric Cardio-Oncology Work Group.

OBJECTIVE: To enhance the understanding of cardiovascular care delivery in childhood cancer patients and survivors. STUDY DESIGN: A 20-question survey was created by the Pediatric Cardio-oncology Work Group of the American College of Cardiology (ACC) Cardio-oncology Section to assess the care, management, and surveillance tools utilized to manage pediatric/young adult cardio-oncology patients. The survey distribution was a collaborative effort between Cardio-oncology Section and membership of the Adult Congenital and Pediatric Cardiology Section (ACPC) of the ACC. RESULTS: Sixty-five individuals, all self-identified as physicians, responded to the survey. Most respondents (n = 58,89%) indicated childhood cancer patients are regularly screened prior to and during cancer therapy at their centers, predominantly by electrocardiogram (75%), standard echocardiogram (58%) and advanced echocardiogram (50%) (i.e. strain, stress echo). Evaluation by a cardiologist prior to/during therapy was reported by only 8(12%) respondents, as compared to post-therapy which was reported by 28 (43%, p < 0.01). The most common indications for referral to cardiology at pediatric centers were abnormal test results (n = 31,48%) and history of chemotherapy exposure (n = 27,42%). Of note, during post-treatment counseling, common cardiovascular risk-factors like blood pressure (31,48%), lipid control (22,34%), obesity & smoking (30,46%) and diet/exercise/weight loss (30,46%) were addressed by fewer respondents than was LV function (72%). CONCLUSIONS: The survey data demonstrates that pediatric cancer patients are being screened by EKG and/or imaging prior to/during therapy at most centers. Our data, however, highlight the potential for greater involvement of a cardiovascular specialist for pre-treatment evaluation process, and for more systematic cardiac risk factor counseling in posttreatment cancer survivors.

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.

Preoperative echocardiographic measures in interrupted aortic arch: Which ones best predict surgical approach and outcome?

OBJECTIVE: It is unclear whether neonates with interrupted aortic arch (IAA) and a smaller left ventricular outflow tract may have improved outcomes with a Yasui operation (ventricular outflow bypass procedure) over a primary complete repair. This study sought to identify preoperative echocardiographic parameters to differentiate which neonates may have improved outcomes with a primary vs Yasui operation. DESIGN: Patient demographics, cardiac surgery type, complications, need for reoperation and/or interventional catheterization, and date of last follow-up were collected on neonates who underwent a biventricular repair for IAA from 2003 to 2014. Preoperative echocardiograms were analyzed for: IAA type, valve annulus size, aortic valve morphology, ventricular size and aortic arch anatomy. RESULTS: Seventy-seven neonates underwent IAA repair between 2003 and 2013. 60 neonates had a primary repair and 17 a Yasui operation. Neonates that underwent a Yasui operation had significantly smaller mitral and aortic valves with aortic arch hypoplasia. Within the primary repair group, a decreasing aortic root z-score on univariate analysis increased the odds of reoperation by twofold [OR = 1.98, 95% CI: (1.15-3.42), P = .014]. A significant interaction between repair type and aortic root z-score was identified on multivariable analysis (P = .039), for neonates with aortic root z-scores less than -2.5, the probability of reoperation during the follow up time period [mean 4.5 years (3.3 months-10 year)] was significantly higher in the primary repair group compared to the Yasui group (64.3% vs 37.5%). CONCLUSIONS: Neonates with IAA and an aortic root z-score less than -2.5 have lower odds of subsequent reoperations with a Yasui operation compared to a primary repair over the follow up period. These findings suggest a Yasui operation should be considered if the preoperative aortic root z-score is less than -2.5. Careful evaluation of these morphologic predictors on preoperative echocardiograms can be helpful in surgical planning in neonates with IAA.

Prediction of Ischemic Heart Disease and Stroke in Survivors of Childhood Cancer.

Purpose We aimed to predict individual risk of ischemic heart disease and stroke in 5-year survivors of childhood cancer. Patients and Methods Participants in the Childhood Cancer Survivor Study (CCSS; n = 13,060) were observed through age 50 years for the development of ischemic heart disease and stroke. Siblings (n = 4,023) established the baseline population risk. Piecewise exponential models with backward selection estimated the relationships between potential predictors and each outcome. The St Jude Lifetime Cohort Study (n = 1,842) and the Emma Children's Hospital cohort (n = 1,362) were used to validate the CCSS models. Results Ischemic heart disease and stroke occurred in 265 and 295 CCSS participants, respectively. Risk scores based on a standard prediction model that included sex, chemotherapy, and radiotherapy (cranial, neck, and chest) exposures achieved an area under the curve and concordance statistic of 0.70 and 0.70 for ischemic heart disease and 0.63 and 0.66 for stroke, respectively. Validation cohort area under the curve and concordance statistics ranged from 0.66 to 0.67 for ischemic heart disease and 0.68 to 0.72 for stroke. Risk scores were collapsed to form statistically distinct low-, moderate-, and high-risk groups. The cumulative incidences at age 50 years among CCSS low-risk groups were < 5%, compared with approximately 20% for high-risk groups ( P < .001); cumulative incidence was only 1% for siblings ( P < .001 v low-risk survivors). Conclusion Information available to clinicians soon after completion of childhood cancer therapy can predict individual risk for subsequent ischemic heart disease and stroke with reasonable accuracy and discrimination through age 50 years. These models provide a framework on which to base future screening strategies and interventions.

Temporal Trends in Utilization of Transthoracic Echocardiography for Common Outpatient Pediatric Cardiology Diagnoses over the Past 15 Years.

BACKGROUND: No data exist regarding the temporal trends in utilization of transthoracic echocardiography (TTE) in an outpatient pediatric cardiology setting. This study evaluates the trends in utilization of TTE for common diagnoses known to have low diagnostic yield and the factors influencing these trends. METHODS: Patients evaluated at our pediatric cardiology clinics from January 2000 to December 2014 and discharged with final diagnoses of innocent murmur, noncardiac chest pain, benign syncope, and palpitations were included. Variables collected retrospectively included patient age, sex, insurance type, distance from clinic, and ordering physician's years of experience since fellowship. RESULTS: Of the 74,881 patients seen by 35 physicians, 36,053 (48.1%) had a TTE. The TTE rates increased from the beginning of 2000 to the end of 2004 (5.2% per year; P < .001) and then steadily declined until the end of 2014 (1.6% per year; P < .001). Utilization for noncardiac chest pain remained the highest, and use in infants increased significantly during the study period (P < .001). After adjusting for all other factors, the following variables were associated with higher TTE utilization: younger age, males, Medicaid insurance, increased distance from clinic, and being seen by less experienced physicians. Temporal trends persisted after adjusting for all these factors. CONCLUSIONS: After an initial surge in TTE utilization from 2000 to 2004, there was a steady decline. This study identifies some important factors influencing these trends. This information could help design quality interventions, but additional factors need to be explored since the trends persist despite adjusting for these factors.