Association Between Remote Monitoring and Interstage Morbidity and Death in Patients With Single-Ventricle Heart Disease Across Socioeconomic Groups.

BACKGROUND: Despite improvements in survival over time, the mortality rate for infants with single-ventricle heart disease remains high. Infants of low socioeconomic status (SES) are particularly vulnerable. We sought to determine whether use of a novel remote monitoring program, the Cardiac High Acuity Monitoring Program, mitigates differences in outcomes by SES. METHODS AND RESULTS: Within the Cardiac High Acuity Monitoring Program, we identified 610 infants across 11 centers from 2014 to 2021. All enrolled families had access to a mobile application allowing for near-instantaneous transfer of patient information to the care team. Patients were divided into SES tertiles on the basis of 6 variables relating to SES. Hierarchical logistic regression, adjusted for potential confounding characteristics, was used to determine the association between SES and death or transplant listing during the interstage period. Of 610 infants, 39 (6.4%) died or were listed for transplant. In unadjusted analysis, the rate of reaching the primary outcome between SES tertiles was similar (P=0.24). Even after multivariable adjustment, the odds of death or transplant listing were no different for those in the middle (odds ratio, 1.7 [95% CI, 0.73-3.94) or highest (odds ratio, 0.997 [95% CI, 0.30, 3.36]) SES tertile compared with patients in the lowest (overall P value 0.4). CONCLUSIONS: In a large multicenter cohort of infants with single-ventricle heart disease enrolled in a digital remote monitoring program during the interstage period, we found no difference in outcomes based on SES. Our study suggests that this novel technology could help mitigate differences in outcomes for this fragile population of patients.

Congenital Pulmonic Valve Dysfunction Treated With SAPIEN 3 Transcatheter Heart Valve (from the COMPASSION S3 Trial).

Significant pulmonary regurgitation (PR) and pulmonary stenosis are common after surgical repair of some congenital heart defects. This prospective, single-arm, multicenter trial enrolled patients who underwent transcatheter heart valve (THV) implantation with a SAPIEN 3 valve to treat dysfunctional right ventricular outflow tract (RVOT) conduits or pulmonic surgical valves (≥ moderate PR and/or mean RVOT gradient ≥35 mm Hg). The primary end point was a nonhierarchical composite of THV dysfunction at 1 year comprising RVOT reintervention, ≥ moderate total PR, and mean RVOT gradient >40 mm Hg. A performance goal of <25% of upper confidence interval (CI) was prespecified for the primary end point, using a 95% exact binomial CI. Patients (n = 58) were enrolled between July 5, 2016 and July 17, 2018, with mean age of 32 years. Prestenting was performed in 53.4%. At discharge, the device success was 98.1% (single valve without explant, < moderate PR, gradient <35 mm Hg). At 30 days, there were no major adjudicated adverse clinical events. At 1 year, the primary end point composite was 4.3% (95% CI 0.5 to 14.5). The composite components were 0% (0 of 56) RVOT reintervention, 2.1% (1 of 47) ≥ moderate PR, and 2.1% (1 of 48) mean RVOT gradient >40 mm Hg. No mortality, endocarditis, thrombosis, or stent fracture were reported at 1 year. In conclusion, the SAPIEN 3 THV was safe and effective in patients with dysfunctional RVOT conduits or previously implanted valves in the pulmonic position to 1 year. Clinical trial registration: NCT02744677; https://clinicaltrials.gov/ct2/show/NCT02744677.

Single ventricular strain measures correlate with peak oxygen consumption in children and adolescents with Fontan circulation.

INTRODUCTION: Children with a single ventricle post-Fontan palliation are at increased risk of poor outcomes with peak oxygen consumption acting as a surrogate outcome marker. The purpose of this study is to evaluate the relationship between peak oxygen consumption and echocardiographic measures of ventricular function and deformation, including ventricular global longitudinal strain and dyssynchrony, in children and adolescents following Fontan palliation. METHODS: Patients (age 8-21 years) with single ventricle post-Fontan palliation were prospectively recruited and participated in an echocardiogram, including views optimised for two-dimensional speckle tracking, and a cardiopulmonary exercise test on a cycle ergometer to maximal volitional fatigue. RESULTS: Thirty-eight patients (mean age 13.7 ± 2.3 years) post-Fontan palliation had either a single left ventricular (n = 20), single right ventricular (n = 14), or biventricular (n = 4) morphology. Peak oxygen consumption (24.9 ± 5.6 ml/kg/minute) was correlated with global longitudinal strain (r = -0.435, p = 0.007), a strain discoordination time to peak index (r = -0.48, p = 0.003), and the presence of an electro-mechanical dyssynchrony strain pattern (p = 0.008). On multivariate regression modelling, these three variables were associated with peak oxygen consumption independently of age and sex. The single right ventricular group had evidence of possible diastolic dysfunction by E/e' compared to the single left ventricular and biventricular groups (p = 0.001). CONCLUSIONS: Strain analysis measures are correlated with peak oxygen consumption in this cohort of children, adolescents, and young adults following Fontan palliation, suggesting that ventricular mechanics may influence the efficiency of the Fontan circulation.

Development of the Residual Lesion Score for congenital heart surgery: the RAND Delphi methodology.

BACKGROUND AND OBJECTIVE: The Residual Lesion Score is a novel tool for assessing the achievement of surgical objectives in congenital heart surgery based on widely available clinical and echocardiographic characteristics. This article describes the methodology used to develop the Residual Lesion Score from the previously developed Technical Performance Score for five common congenital cardiac procedures using the RAND Delphi methodology. METHODS: A panel of 11 experts from the field of paediatric and congenital cardiology and cardiac surgery, 2 co-chairs, and a consultant were assembled to review and comment on validity and feasibility of measuring the sub-components of intraoperative and discharge Residual Lesion Score for five congenital cardiac procedures. In the first email round, the panel reviewed and commented on the Residual Lesion Score and provided validity and feasibility scores for sub-components of each of the five procedures. In the second in-person round, email comments and scores were reviewed and the Residual Lesion Score revised. The modified Residual Lesion Score was scored independently by each panellist for validity and feasibility and used to develop the "final" Residual Lesion Score. RESULTS: The Residual Lesion Score sub-components with a median validity score of ≥7 and median feasibility score of ≥4 that were scored without disagreement and with low absolute deviation from the median were included in the "final" Residual Lesion Score. CONCLUSION: Using the RAND Delphi methodology, we were able to develop Residual Lesion Score modules for five important congenital cardiac procedures for the Pediatric Heart Network's Residual Lesion Score study.

Development and Initial Validation of a Frailty Score for Pediatric Patients with Congenital and Acquired Heart Disease.

Frailty is a multi-dimensional clinical syndrome that is associated with increased morbidity and mortality and decreased quality of life. Children/adolescents with heart disease (HD) perform significantly worse for each frailty domain compared to non-HD peers. Our study aimed to create a composite frailty score (CFS) that can be applied to children/adolescents with HD and evaluate associations between the CFS and outcomes. Children and adolescents (n = 30) with HD (73% single ventricle, 20% heart failure, 7% pulmonary hypertension) were recruited from 2016 to 2017 (baseline). Five frailty domains were assessed at baseline using measures validated for pediatrics: (1) Slowness: 6-min walk test; (2) Weakness: handgrip strength; (3) Fatigue: PedsQL Multi-dimensional Fatigue Scale; (4) Body composition: triceps skinfold thickness; and (5) Physical activity questionnaire. Frailty points per domain (range = 0-5) were assigned based on z-scores or raw questionnaire scores and summed to produce a CFS (0 = least frail; 25 = most frail). Nonparametric bootstrapping was used to identify correlations between CFS and cross-sectional change in outcomes over 2.2 ± 0.2 years. The mean CFS was 12.5 ± 3.5. In cross-sectional analyses of baseline data, correlations (|r|≥ 0.30) were observed between CFS and NYHA class, the number of ancillary specialists, total prescribed medications, heart failure medications/day, exercise test derived chronotropic index and percent predicted VO2peak, and between child and parent proxy PEDsQL. At follow-up, CFS was correlated with an increase in the number of heart failure medications (r = 0.31). CFS was associated with cross-sectional outcomes in youth with heart disease. Longitudinal analyses were limited by small sample sizes due to loss to follow-up.

Ability of Video Telemetry to Predict Unplanned Hospital Admissions for Single Ventricle Infants.

Background Our Cardiac High Acuity Monitoring Program (CHAMP) uses home video telemetry (HVT) as an adjunct to monitor infants with single ventricle during the interstage period. This study describes the development of an objective early warning score using HVT, for identification of infants with single ventricle at risk for clinical deterioration and unplanned hospital admissions (UHA). Methods and Results Six candidate scoring parameters were selected to develop a pragmatic score for routine evaluation of HVT during the interstage period. We evaluated the individual and combined ability of these parameters to predict UHA. All infants with single ventricle monitored at home by CHAMP between March 2014 and March 2018 were included. Videos obtained within 48 hours before UHA were compared with videos obtained at baseline. We used binary logistic regression models and receiver operating characteristic curves to evaluate the parameters' performance in discriminating the outcome of interest. Thirty-nine subjects with 64 UHA were included. We compared 64 pre-admission videos to 64 paired baseline videos. Scoring was feasible for a mean of 91.6% (83.6%-98%) of all observations. Three different HVT score models were proposed, and a final model composed of respiratory rate, respiratory effort, color, and behavior exhibited an excellent discriminatory capability with an area under the receiver operating characteristic curve of 93% (89%-98%). HVT score of 5 was associated with specificity of 93.8% and sensitivity of 88.7% in predicting UHA. Conclusions We developed a feasible and reproducible HVT score that can serve as a tool to predict UHA in infants with single ventricle. Future directions involve prospective, multicenter validation of this tool.

Alterra Adaptive Prestent and SAPIEN 3 THV for Congenital Pulmonic Valve Dysfunction: An Early Feasibility Study.

OBJECTIVES: The aim of this study was to demonstrate the safety and functionality of the Alterra Adaptive Prestent and SAPIEN 3 transcatheter heart valve (THV) in patients with dysfunctional, dilated right ventricular outflow tract (RVOT) greater or equal to moderate pulmonary regurgitation (PR). BACKGROUND: Significant variations in the size and morphology of the RVOT affect the placement of transcatheter pulmonary valves. The Alterra Prestent internally reduces and reconfigures the RVOT, providing a stable landing zone for the 29-mm SAPIEN 3 THV. METHODS: Eligible patients had moderate or greater PR, weighed >20 kg, and had RVOT diameter 27 to 38 mm and length >35 mm. The primary endpoint was device success, a 5-item composite: 1 Alterra Prestent deployed in the desired location, 1 SAPIEN 3 THV implanted in the desired location within the Prestent, right ventricular-to-pulmonary artery peak-to-peak gradient <35 mm Hg after THV implantation, less than moderate PR at discharge, and no explantation 24 h post-implantation. The secondary composite endpoint was freedom from THV dysfunction (RVOT/pulmonary valve (PV) reintervention, greater or equal to moderate total PR, mean RVOT/PV gradient ≥ 35 mm Hg at 30 days and 6 months. Descriptive statistics are reported. RESULTS: Enrolled patients (N = 15) had a median age and weight of 20 years and 61.7 kg, respectively; 93.3% were in New York Heart Association functional class I or II. Device success was 100%. No staged procedures were necessary. No THV dysfunction was reported to 6 months. No serious safety signals were reported. CONCLUSIONS: This early feasibility study demonstrated the safety and functionality of the Alterra Adaptive Prestent in patients with congenital RVOT dysfunction and moderate or greater PR. Durability and long-term outcome data are needed.

Physical Activity Patterns in Children and Adolescents With Heart Disease.

PURPOSE: To quantify the differences in daily physical activity (PA) patterns, intensity-specific volumes, and PA bouts in youth with and without heart disease (HD). METHODS: Seven-day PA was measured on children/adolescents with HD (n = 34; median age 12.4 y; 61.8% male; 70.6% single ventricle, 17.7% heart failure, and 11.8% pulmonary hypertension) and controls without HD (n = 22; median age 12.3 y; 59.1% male). Mean counts per minute were classified as sedentary, light, and moderate to vigorous PA (MVPA), and bouts of MVPA were calculated. PA was calculated separately for each hour of wear time from 8:00 to 22:00. Multilevel linear mixed modeling compared the outcomes, stratifying by group, time of day, and day part (presented as median percentage of valid wear time [interquartile range]). RESULTS: Compared with the controls, the HD group had more light PA (33.9% [15%] vs 29.6% [9.5%]), less MVPA (1.7% [2.5%] vs 3.2% [3.3%]), and more sporadic bouts (97.4% [5.7%] vs 89.9% [9.2%]), but fewer short (2.0% [3.9%] vs 7.1% [5.7%]) and medium-to-long bouts (0.0% [1.9%] vs 1.6% [4.6%]) of MVPA. The HD group was less active in the late afternoon, between 15:00 and 17:00 (P < .03). There were no differences between groups in sedentary time. CONCLUSION: Children/adolescents with HD exhibit differences in intensity-specific volumes, PA bouts, and daily PA patterns compared with controls.

Interstage Home Monitoring for Infants With Single Ventricle Heart Disease: Education and Management: A Scientific Statement From the American Heart Association.

This scientific statement summarizes the current state of knowledge related to interstage home monitoring for infants with shunt-dependent single ventricle heart disease. Historically, the interstage period has been defined as the time of discharge from the initial palliative procedure to the time of second stage palliation. High mortality rates during the interstage period led to the implementation of in-home surveillance strategies to detect physiologic changes that may precede hemodynamic decompensation in interstage infants with single ventricle heart disease. Adoption of interstage home monitoring practices has been associated with significantly improved morbidity and mortality. This statement will review in-hospital readiness for discharge, caregiver support and education, healthcare teams and resources, surveillance strategies and practices, national quality improvement efforts, interstage outcomes, and future areas for research. The statement is directed toward pediatric cardiologists, primary care providers, subspecialists, advanced practice providers, nurses, and those caring for infants undergoing staged surgical palliation for single ventricle heart disease.

Translation of the Frailty Paradigm from Older Adults to Children with Cardiac Disease.

Children and adolescents with cardiac disease (CCD) have significant morbidity and lower quality of life. However, there are no broadly applicable tools similar to the frailty score as described in the elderly, to define functional phenotype in terms of physical capability and psychosocial wellbeing in CCD. The purpose of this study is to investigate the domains of the frailty in CCD. We prospectively recruited CCD (8-17.5 years old, 70% single ventricle, 27% heart failure, 12% pulmonary hypertension; NYHA classes I, II and III) and age and gender matched healthy controls (total n = 56; CCD n = 34, controls n = 22; age 12.6 ± 2.6 years; 39.3% female). We measured the five domains of frailty: slowness, weakness, exhaustion, body composition and physical activity using developmentally appropriate methods. Age and gender-based population norms were used to obtain Z scores and percentiles for each measurement. Two-tailed t-tests were used to compare the two groups. The CCD group performed significantly worse in all five domains of frailty compared to healthy controls. Slowness: 6-min walk test with Z score -3.9 ± 1.3 vs -1.4 ± 1.3, p < 0.001; weakness: handgrip strength percentile 18.9 ± 20.9 vs 57.9 ± 26.0, p < 0.001; exhaustion: multidimensional fatigue scale percentile 63.7 ± 13.5 vs 83.3 ± 14.4, p < 0.001; body composition: height percentile 43.4 ± 29.5 vs 71.4 ± 25.2, p < 0.001, weight percentile 46.0 ± 36.0 vs 70.9 ± 24.3, p = 0.006, BMI percentile 48.4 ± 35.5 vs 66.9 ± 24.2, p = 0.04, triceps skinfold thickness 41.0 ± 24.0 vs 54.4 ± 22.1, p = 0.04; physical activity: pediatric activity questionnaire score 2 ± 0.6 vs 2.7 ± 0.6, p < 0.001. The domains of frailty can be quantified in children using developmentally appropriate methods. CCD differ significantly from controls in all five domains, supporting the concept of quantifying the domains of frailty. Larger longitudinal studies are needed to study frailty in CCD and examine if it predicts adverse health outcomes.Clinical Trial Registration: The ClinicalTrials.gov identification number is NCT02999438. https://clinicaltrials.gov/ct2/show/NCT02999438.

Comparison of echocardiographic measurements to invasive measurements of diastolic function in infants with single ventricle physiology: a report from the Pediatric Heart Network Infant Single Ventricle Trial.

BACKGROUND: While echocardiographic parameters are used to quantify ventricular function in infants with single ventricle physiology, there are few data comparing these to invasive measurements. This study correlates echocardiographic measures of diastolic function with ventricular end-diastolic pressure in infants with single ventricle physiology prior to superior cavopulmonary anastomosis. METHODS: Data from 173 patients enrolled in the Pediatric Heart Network Infant Single Ventricle enalapril trial were analysed. Those with mixed ventricular types (n = 17) and one outlier (end-diastolic pressure = 32 mmHg) were excluded from the analysis, leaving a total sample size of 155 patients. Echocardiographic measurements were correlated to end-diastolic pressure using Spearman's test. RESULTS: Median age at echocardiogram was 4.6 (range 2.5-7.4) months. Median ventricular end-diastolic pressure was 7 (range 3-19) mmHg. Median time difference between the echocardiogram and catheterisation was 0 days (range -35 to 59 days). Examining the entire cohort of 155 patients, no echocardiographic diastolic function variable correlated with ventricular end-diastolic pressure. When the analysis was limited to the 86 patients who had similar sedation for both studies, the systolic:diastolic duration ratio had a significant but weak negative correlation with end-diastolic pressure (r = -0.3, p = 0.004). The remaining echocardiographic variables did not correlate with ventricular end-diastolic pressure. CONCLUSION: In this cohort of infants with single ventricle physiology prior to superior cavopulmonary anastomosis, most conventional echocardiographic measures of diastolic function did not correlate with ventricular end-diastolic pressure at cardiac catheterisation. These limitations should be factored into the interpretation of quantitative echo data in this patient population.

3-Year Outcomes of the Edwards SAPIEN Transcatheter Heart Valve for Conduit Failure in the Pulmonary Position From the COMPASSION Multicenter Clinical Trial.

OBJECTIVES: This study provides the 3-year follow-up results of the COMPASSION (Congenital Multicenter Trial of Pulmonic Valve Regurgitation Studying the SAPIEN Transcatheter Heart Valve) trial. Patients with moderate to severe pulmonary regurgitation and/or right ventricular outflow tract conduit obstruction were implanted with the SAPIEN transcatheter heart valve (THV). BACKGROUND: Early safety and efficacy of the Edwards SAPIEN THV in the pulmonary position have been established through a multicenter clinical trial. METHODS: Eligible patients were included if body weight was >35 kg and in situ conduit diameter was ≥16 and ≤24 mm. Adverse events were adjudicated by an independent clinical events committee. Three-year clinical and echocardiographic outcomes were evaluated in these patients. RESULTS: Fifty-seven of the 63 eligible patients were accounted for at the 3-year follow-up visit from a total of 69 implantations in 81 enrolled patients. THV implantation was indicated for pulmonary stenosis (7.6%), regurgitation (12.7%), or both (79.7%). Twenty-two patients (27.8%) underwent implantation of 26-mm valves, and 47 patients received 23-mm valves. Functional improvement in New York Heart Association functional class was observed in 93.5% of patients. Mean peak conduit gradient decreased from 37.5 ± 25.4 to 17.8 ± 12.4 mm Hg (p < 0.001), and mean right ventricular systolic pressure decreased from 59.6 ± 17.7 to 42.9 ± 13.4 mm Hg (p < 0.001). Pulmonary regurgitation was mild or less in 91.1% of patients. Freedom from all-cause mortality at 3 years was 98.4%. Freedom from reintervention was 93.7% and from endocarditis was 97.1% at 3 years. There were no observed stent fractures. CONCLUSIONS: Transcatheter pulmonary valve replacement using the Edwards SAPIEN THV demonstrates excellent valve function and clinical outcomes at 3-year follow-up.

Improving Wait Time for Patients in a Pediatric Echocardiography Laboratory - a Quality Improvement Project.

BACKGROUND: Prolonged wait times for echocardiograms in the outpatient pediatric cardiology clinic led to patient and provider dissatisfaction at our institution. The aims of this project were to measure our baseline performance with regard to echocardiogram wait time (EWT), to implement a formal quality improvement (QI) program to improve EWT, and to measure the impact of QI on EWT. METHODS: A QI team was formed comprising of cardiologists (A.P., T.S.), sonographer (A.W.), and QI mentor (J.M.). EWT was defined as time in minutes from initiation of the order in the electronic medical record to start of the echocardiogram. Goal EWT was set as ≤ 20 minutes for 90% patients. Flowcharts were created after process observation to identify sources of potential delay contributing to EWT. QI methodology such as driver diagrams were utilized to identify interventions, which were then implemented and studied as Plan-Do-Study-Act cycles. RESULTS: Sequential interventions included early start time, huddles involving clinic and echo laboratory staff, patient tracking system, and repurposing of a clinic room for echo. EWT was tracked for 840 patients. Mean EWT was 22.5 ± 17.5 minutes at baseline and decreased to 15.3 ± 7.8 minutes postintervention (P < 0.001). Postintervention, 81% of the patients waited < 20 minutes for their echo, and 98% patients waited < 30 minutes, compared with baseline numbers of 62% and 76%, respectively (P < 0.001). CONCLUSIONS: We were able to utilize QI methodology to derive interventions and track changes, resulting in quantifiable improvement in EWT in a busy pediatric echo laboratory.

Interstage Outcomes in Infants With Single Ventricle Heart Disease Comparing Home Monitoring Technology to Three-Ring Binder Documentation: A Randomized Crossover Study.

BACKGROUND: Interstage outcomes for infants with single ventricle remain suboptimal. We have previously described a tablet PC-based platform Cardiac High Acuity Monitoring Program (CHAMP) for remote monitoring which provides immediate access to data, videos, and instant alerts to our single ventricle care team. METHODS: This study compares traditional three-ring binder monitoring (Binder) to CHAMP using a randomized crossover design to evaluate mortality, resource utilization, and caregiver experience. At discharge, all single ventricle infants were monitored using Binder and randomized to receive CHAMP at either one or two months postdischarge. One month after randomization, caregivers could choose either Binder or CHAMP for the remainder of the interstage period. Caregivers experience was recorded using surveys. RESULTS: Enrollment included 31 single ventricle infants from May 2014 to June 2015. There was no interstage mortality over 4,911 total interstage days (median: 144/patient). Of 73 readmissions, 45 were unplanned. Of the initial 23 unplanned readmissions, 13 were found to have been based on data obtained exclusively through CHAMP (as instant alerts or based on data review) rather than caregiver concerns. Due to concerns regarding patient safety, additional enrollment was stopped. The CHAMP use was associated with significantly fewer unplanned intensive care unit days/100 interstage days, shorter delays in care, lower resource utilization at readmissions, and lower incidence of interstage growth failure and was preferred by a majority of caregivers. CONCLUSIONS: These findings suggest that CHAMP may offer benefits over Binder (improved interstage outcomes, delays in care, and caregiver experience). These findings should be tested across multiple centers in larger populations.

Longitudinal measures of deformation are associated with a composite measure of contractility derived from pressure-volume loop analysis in children.

Aims: The relationship between echocardiographic measures of left ventricular (LV) systolic function and reference-standard measures have not been assessed in children. The objective of this study was to assess the validity of echocardiographic indices of LV systolic function via direct comparison to a novel composite measure of contractility derived from pressure-volume loop (PVL) analysis. Methods and results: Children with normal loading conditions undergoing routine left heart catheterization were prospectively enrolled. PVLs were obtained via conductance catheters. A composite invasive composite contractility index (ICCI) was developed using data reduction strategies to combine four measures of contractility derived from PVL analysis. Echocardiograms were performed immediately after PVL analysis under the same anesthetic conditions. Conventional and speckle-tracking echocardiographic measures of systolic function were measured. Of 24 patients, 18 patients were heart transplant recipients, 6 patients had a small patent ductus arteriosus or small coronary fistula. Mean age was 9.1 ± 5.6 years. Upon multivariable regression, longitudinal strain was associated with ICCI (ß = -0.54, P = 0.02) while controlling for indices of preload, afterload, heart rate, and LV mass under baseline conditions. Ejection fraction and shortening fraction were associated with LV mass and load indices, but not contractility. Conclusion: Speckle-tracking derived longitudinal strain is associated ICCI in children with normal loading conditions. Longitudinal measures of deformation appear to accurately assess LV contractility in children.

Echocardiographic Detection of Increased Ventricular Diastolic Stiffness in Pediatric Heart Transplant Recipients: A Pilot Study.

BACKGROUND: Pediatric heart transplant recipients are at risk for increased left ventricular (LV) diastolic stiffness. However, the noninvasive evaluation of LV stiffness has remained elusive in this population. The objective of this study was to compare novel echocardiographic measures of LV diastolic stiffness versus gold-standard measures derived from pressure-volume loop (PVL) analysis in pediatric heart transplant recipients. METHODS: Patients undergoing left heart catheterization were prospectively enrolled. PVLs were obtained via conductance. The end-diastolic pressure-volume relationship was obtained via balloon occlusion. The stiffness constant, ß, was calculated. Echocardiographic measures of diastolic function were derived from spectral and tissue Doppler and two-dimensional speckle-tracking. Ventricular volumes were measured using three-dimensional echocardiography. The novel echocardiographic estimates of ventricular stiffness included E:e'/end-diastolic volume (EDV) and E:early diastolic strain rate/EDV. RESULTS: Of 24 children, 18 were heart transplant recipients. Six control patients had hemodynamically insignificant patent ductus arteriosus or coronary fistula. The mean age was 9.1 ± 5.6 years. Median end-diastolic pressure was 9 mm Hg (interquartile range, 8-13 mm Hg). Lateral E:e'/EDV (r = 0.59, P < .01), septal E:e'/EDV (r = 0.57, P < .01), and (E:circumferential early diastolic strain rate)/EDV (r = 0.54, P < .01) correlated with ß. Lateral E:e'/EDV displayed a C statistic of 0.93 in detecting patients with abnormal LV stiffness (ß > 0.015 mL-1). A lateral E:e'/EDV of >0.15 mL-1 had 89% sensitivity and 93% specificity in detecting an abnormal ß. CONCLUSIONS: Echocardiographic estimates of ventricular stiffness may be accurate compared with the gold standard in pediatric heart transplant recipients. The clinical usefulness of these noninvasive measures in assessing LV stiffness merits further study in children.

Medium-term assessment of cardiac function in pediatric cancer survivors. Comparison of different echocardiographic methods, cardiac MRI and cardiac biomarker testing in adolescent cancer survivors.

PURPOSE: To evaluate the feasibility and correlation of 3D echocardiography (echo) and cardiac biomarkers with cardiac MRI, in surveillance of cardiac function for cancer survivors. METHODS: Subjects ≥10 years of age who have survived >2 years after completion of cancer treatment from a single center were enrolled. Cardiac MRI and 3D echo images were obtained on the same day when routine echo was obtained. On the same day, along with annual routine blood test, cardiac biomarkers N-terminal pro-B-type natriuretic peptide levels (NT-proBNP) and troponin-I levels were also measured. RESULTS: Cardiac MRI was feasible in all 50 subjects. Three-dimensional echo and 2D echo images were of poor quality in four subjects. With a median duration of remission of 10 years, there were four subjects with mild LV dysfunction (cardiac MRI LV EF of<53%). None had MRI EF <50%, and nine subjects had LVEF <55%. M-mode echo overestimated EF more than 2D and 3D echo. Two-dimensional and 3D echo methods had much tighter limits of agreement for LV EF. For measurement of LVEF, 3D echo had a lower % error than 2D echo or M-mode echo. One subject had an abnormal troponin-I level and another one had an elevated NT-proBNP. CONCLUSIONS: Three-dimensional echo can be performed in most adolescent cancer survivors, and it correlates well with MRI. Further large-scale research is required in assessing utility of cardiac biomarkers in pediatric cancer survivors.

Speckle-Tracking Echocardiographic Measures of Right Ventricular Diastolic Function Correlate with Reference Standard Measures Before and After Preload Alteration in Children.

The accuracy of echocardiographic measures of right ventricular (RV) diastolic function has been sparsely studied. Our objective was to evaluate the correlation between echocardiographic and reference standard measures of RV diastolic function derived from micromanometer pressure analysis before and after preload alteration in children. Echocardiograms and micromanometer pressure analyses were prospectively performed before and after fluid bolus in children undergoing right heart catheterization. The isovolumic relaxation time constant (τ) and end-diastolic pressure (EDP) were measured. Conventional and speckle-tracking echocardiographic (STE) parameters of RV systolic and diastolic function were assessed. Normal saline bolus was given to increase RV EDP by 20 %. Twenty-eight studies were performed in 22 patients with congenital heart disease or postheart transplantation. Mean age was 8.7 ± 6.1 years. RV longitudinal early diastolic strain rate (EDSR) correlated with τ before (r = 0.57, p = 0.001) and after fluid bolus (r = 0.48, p = 0.008). No conventional echocardiographic measures correlated with τ both before and after fluid bolus. Multiple regression analysis revealed RV EDSR and LV circumferential EDSR as independent predictors of RV τ. There were no independent predictors of EDP. RV EDSR appears to correlate with the reference standard measure of early active ventricular relaxation in children at baseline and after changes in preload. Conventional echocardiographic measures of diastolic function were not predictive of diastolic function after preload alteration. Future studies should assess the prognostic significance of STE measures of diastolic function in this population.