Hemodynamic and Echocardiographic Predictors of Mortality in Pediatric Patients on Venoarterial Extracorporeal Membrane Oxygenation: A Multicenter Investigation.

BACKGROUND: Venoarterial extracorporeal membrane oxygenation (ECMO) supports patients with advanced cardiac dysfunction; however, mortality occurs in a significant subset of patients. The authors performed a multicenter, prospective study to determine hemodynamic and echocardiographic predictors of mortality in children placed on ECMO for cardiac support. METHODS: Over 8 years, six heart centers prospectively assessed echocardiographic and hemodynamic variables on full and minimum ECMO flow. Sixty-three patients were enrolled, ranging in age from 1 day to 16 years. Hemodynamic measurements included heart rate, vasoactive inotropic score, arteriovenous oxygen difference, pulse pressure, and lactate. Echocardiographic variables included shortening fraction, ejection fraction (EF), right ventricular fractional area change, outflow tract Doppler-derived stroke distance (velocity-time integral [VTI]), and degree of atrioventricular valve regurgitation. Patients were stratified into two groups: those who were able to wean within 48 hours of assessment and survived without ventricular assist devices or orthotopic heart transplantation (successful wean group) and those with unsuccessful weaning. For each patient, variables were compared between full and minimum ECMO flow for each group. RESULTS: Thirty-eight patients (60%) formed the unsuccessful group (two with ventricular assist devices, four with orthotopic heart transplantation, 24 deaths), and 25 constituted the successful wean group. At minimum flow, higher EF (53 ± 16% vs 40 ± 20%, P = .0094), less mitral regurgitation (0.8 ± 0.9 vs 1.4 ± 0.9, P = .0329), and lower central venous pressure (12.0 ± 3.9 vs 14.7 ± 5.4 mm Hg), along with higher VTI (9.0 ± 2.9 vs 6.8 ± 3.7 cm, P = .0154), correlated successful weaning. A longer duration of ECMO (8 vs 5 days, P < .0002) was associated with unsuccessful weaning. Multivariate logistic regression predicted minimum-flow EF and VTI to independently predict successful weaning with cutoff values by receiver operating characteristic analysis of EF > 41% (area under the curve, 0.712; P = .0005) and VTI > 7.9 cm (area under the curve, 0.729; P = .0010). CONCLUSIONS: Diminished VTI or EF during ECMO weaning predicts the need for orthotopic heart transplantation or ventricular assist device support or death in children on ECMO for cardiac dysfunction. Increased postwean central venous pressure or mitral regurgitation along with a prolonged ECMO course also predicted these adverse outcomes. These measurements should be used to help discriminate which patients will require alternative methods of circulatory support for survival.

Longitudinal Assessment of Right Ventricular Function in Hypoplastic Left Heart Syndrome.

Overall survival of patients with hypoplastic left heart syndrome (HLHS) has shown continued improvement. Right ventricular (RV) dysfunction, in the long term, adversely affects prognosis in these patients. This study examines changes in echocardiographic markers of RV function in a longitudinal cohort. We retrospectively reviewed patients with HLHS managed at our institution from 7/1994 to 1/2016. Follow-up included surgical and clinical data, and echocardiographic measures. Measures of RV function preceding and following all three stages of single ventricular palliation were collected. Freedom from transplant-free survival was assessed by Kaplan-Meier analysis. Multivariable associations with time to death or transplant were explored using the Cox proportional hazards model. A total of 120 patients with HLHS were identified. Norwood operation was performed in all patients. The probability of survival for the cohort was 71 ± 4.4%, 69 ± 4.5% and 66 ± 4.7% at 1, 2 and 5 years respectively after stage I Norwood operation. RV fractional area change (FAC), compared to post-Norwood was decreased at all subsequent stages with the greatest change noted post-superior cavo-pulmonary shunt from 40.7 ± 9.3% to 31.1 ± 8.3% (p < 0.001). Similarly, tricuspid valve annular systolic excursion (TAPSE) Z-score declined from -2.9 ± 1.3 to -9.7 ± 1.3 (p < 0.001) with a decrement at every stage of evaluation. In comparison to patients with post-Norwood RV FAC >35% and TAPSE Z-score > -5, patients with RV FAC ≤ 35% and TAPSE Z-score ≤ -5 had a significantly lower transplant-free survival (p < 0.0001). In patients with HLHS undergoing staged palliation, decrement in RV function manifests longitudinally. Post-Norwood RV FAC and TAPSE Z-score appear to be early markers of poor outcome in this population.

Efficacy of a centralized, blended electronic, and human intervention to improve direct oral anticoagulant adherence: Smartphones to improve rivaroxaban ADHEREnce in atrial fibrillation (SmartADHERE) a randomized clinical trial.

BACKGROUND: Improving adherence to direct oral anticoagulants (DOAC) is challenging, and simple text messaging reminders have not been effective. METHODS: SmartADHERE was a randomized trial that tested a personalized digital and human direct oral anticoagulant adherence intervention compared to usual care. Eligibility required age ≥ 18, newly-prescribed (≤90 days) rivaroxaban for atrial fibrillation (AF), 1 of 4 at-risk criteria for nonadherence, and a smartphone. The intervention consisted of combination of a medication management smartphone app, daily app-based reminders, adaptive text messaging, and phone-based counseling for severe nonadherence. The primary outcome was the proportion of days covered by rivaroxaban (PDC) at 6 months. There were 25 U.S. sites, all cardiology and electrophysiology outpatient practices, activated for a target sample size of 378, but the study was terminated by the sponsor prior to reaching target enrollment. RESULTS: There were 139 participants (age 65±9.6 years, 30% female, median CHA2DS2-VASc score 3 with IQR 2 to 4, mean total medication burden 7.7±4.4). DOAC adherence was high in both arms with no difference in the primary outcome (PDC 0.86±0.25 intervention vs 0.88±0.25 control, p=0.62) or in secondary outcomes including PDC ≥ 0.80 and medication persistence. Per protocol analyses had similar results. Because of the high overall PDC, the likelihood to answer the primary hypothesis was only 51% even if target enrollment were achieved. There were no study-related adverse events. CONCLUSIONS: The use of a centralized digital and human adherence intervention was feasible across multiple sites. Overall adherence was much higher than expected despite prescreening for at-risk individuals. SmartADHERE illustrates the challenges of trials of behavioral and technology interventions, where enrollment itself may lead to selection bias or treatment effects. Pragmatic study designs, such as cluster randomization or stepped-wedge implementation, should be considered to improve enrollment and generalizability.

Interstage evaluation of homograft-valved right ventricle to pulmonary artery conduits for palliation of hypoplastic left heart syndrome.

OBJECTIVE: Palliation of hypoplastic left heart syndrome with a standard nonvalved right ventricle to pulmonary artery conduit results in an inefficient circulation in part due to diastolic regurgitation. A composite right ventricle pulmonary artery conduit with a homograft valve has a hypothetical advantage of reducing regurgitation, but may differ in the propensity for stenosis because of valve remodeling. METHODS: This retrospective cohort study included 130 patients with hypoplastic left heart syndrome who underwent a modified stage 1 procedure with a right ventricle to pulmonary artery conduit from 2002 to 2015. A composite valved conduit (cryopreserved homograft valve anastomosed to a polytetrafluoroethylene tube) was placed in 100 patients (47 aortic, 32 pulmonary, 13 femoral/saphenous vein, 8 unknown), and a nonvalved conduit was used in 30 patients. Echocardiographic functional parameters were evaluated before and after stage 1 palliation and before the bidirectional Glenn procedure, and interstage interventions were assessed. RESULTS: On competing risk analysis, survival over time was better in the valved conduit group (P = .040), but this difference was no longer significant after adjustment for surgical era. There was no significant difference between groups in the cumulative incidence of bidirectional Glenn completion (P = .15). Patients with a valved conduit underwent more interventions for conduit obstruction in the interstage period, but this difference did not reach significance (P = .16). There were no differences between groups in echocardiographic parameters of right ventricle function at baseline or pre-Glenn. CONCLUSIONS: In this cohort of patients with hypoplastic left heart syndrome, inclusion of a valved right ventricle to pulmonary artery conduit was not associated with any difference in survival on adjusted analysis and did not confer an identifiable benefit on right ventricle function.

Impact of Accreditation on Quality in Echocardiograms: A Quantitative Approach.

BACKGROUND: Accreditation through the Intersocietal Accreditation Commission (IAC) is believed but not proven to increase quality in imaging. The goal of this study was to use quality metrics to evaluate the impact of accreditation on quality in pediatric echocardiography. METHODS: This is a retrospective study comparing quality metrics in 236 pediatric transthoracic echocardiograms in patients with congenital heart disease from (1) California Pacific Medical Center (CPMC), a community hospital, before and after IAC accreditation, and (2) the IAC-accredited Lucile Packard Children's Hospital (LPCH), an academic children's referral center, during equivalent eras. Consecutive patients who required cardiac intervention were matched between sites based on age, complexity, and time period. Two raters independently evaluated echocardiograms for image quality and study comprehensiveness. A third rater reviewed echocardiogram reports and medical charts for report completeness and diagnostic accuracy. Diagnostic error characterization was performed by consensus among the three raters. Report completeness was an IAC tool approved for maintenance of certification. The remaining quality metrics were developed by the American College of Cardiology Adult Congenital Pediatric Cardiology Quality Metrics Working Group initiative. RESULTS: At each site, 74 echocardiograms in the era before CPMC accreditation and 44 echocardiograms in the era after CPMC accreditation were included. There was no significant difference in image quality and diagnostic accuracy at CPMC before and after accreditation. Study comprehensiveness and report completeness improved at CPMC after accreditation (P < .001). CONCLUSIONS: Accreditation through the IAC leads to increased study comprehensiveness and report completeness. Image quality and diagnostic accuracy did not differ significantly before and after IAC accreditation. We recommend further studies to assess the effects of accreditation on quality in echocardiography and patient outcomes.

Left Ventricular Systolic Myocardial Deformation: A Comparison of Two- and Three-Dimensional Echocardiography in Children.

BACKGROUND: The clinical applicability and reliability of three-dimensional (3D) speckle-tracking echocardiography has not been well studied in pediatric patients. The aim of this study was to compare two-dimensional (2D) echocardiography and 3DE real-time full-volume-derived strain and rotation indices in healthy children and patients with dilated cardiomyopathy (DCM). METHODS: Children with either normal function or DCM were prospectively recruited in an outpatient setting, and deformation indices, including circumferential, radial, and longitudinal strain and torsion, were measured by 2D and 3D echocardiography. Control subjects were compared with patients using the Mann-Whitney U test, correlations between 2D and 3D measurements were analyzed using Spearman correlation analysis, and reproducibility analyses are reported using intraclass correlation coefficients and coefficient of variations. RESULTS: The study cohort consisted of 15 patients (47%) with DCM and 17 control subjects (53%). The median age of the cohort was 13.4 years (range, 5.7-19.3 years). By both 2D and 3D analysis, magnitudes of global longitudinal (P = .01), circumferential (P = .007), and radial (P = .004) strain were significantly lower in patients with DCM in comparison with control subjects. Using receiver operating characteristic curves, lower values of absolute circumferential (area under the curve = 0.95, P < .0001) and longitudinal (area under the curve = 0.93, P < .0001) strain were associated with left ventricular dysfunction. No difference was noted in torsion between control subjects and patients. Three-dimensional analysis was superior to 2D analysis in terms of intraobserver, interobserver, and test-retest reliability. CONCLUSIONS: Left ventricular deformation shows significant changes while torsion is preserved in outpatients with DCM compared with control subjects. Three-dimensional global strain can discriminate subtle left ventricular dysfunction and has better reproducibility in comparison with 2D echocardiography. High-resolution 3D imaging is a useful clinical assessment tool for cardiac performance and may overcome some of the limitations of 2D analysis.

Pediatric Echocardiography by Work Relative Value Units: Is Study Complexity Adequately Captured?

BACKGROUND: Present resource-based relative value unit (RVU) assignment for echocardiography is based on Current Procedural Terminology (CPT) codes, which do not incorporate complexity of diagnosis, time spent for image acquisition, or interpretation of echocardiograms. The objective of this study was to determine whether CPT-based RVU assignment accurately reflects physician effort in performing and interpreting pediatric echocardiographic examinations. METHODS: Cardiac complexity category (CCC) and physician time for study interpretation of 123 echocardiograms (June to September 2013) were prospectively assigned. Categories included (1) focused effusion/function evaluation, (2) normal anatomy/focused preterm infant studies, (3) acquired heart disease, (4) congenital heart disease excluding single ventricles, (5) single ventricles including heterotaxy syndrome, and (6) hearts on mechanical support. Subsequently, a random sample of echocardiograms (March to August 2013) were retrospectively analyzed, and each study was assigned a CCC and an extrapolated median interpretation time (MIT) on the basis of prospective data collection. Assigned work RVUs based on CPT codes were recorded. Comparisons were made between CCC and time for study interpretation, work RVUs, number of images acquired, and total scan time. RESULTS: A total of 933 echocardiograms were analyzed: 198 (21%), 174 (19%), 98 (11%), 359 (35%), 84 (9%), and 20 (2%) studies in CCCs 1 to 6, respectively. Total scan time, MIT, number of images, and work RVUs were different among CCCs (P < .0001). However, among the more complex studies (CCCs 2-5), work RVUs were similar, while number of images obtained and MIT were different (P < .001). Correlation analysis showed no association between work RVUs and CCC, total scan, or number of images per study. Compared with older patients, work RVUs of studies in children <2 years of age were lower, while all other markers of study complexity were higher (P < .05). CONCLUSIONS: Current CPT-based assignment of work RVUs does not discriminate study complexity and physician effort. The results of this study highlight the need for a refined system that accurately assesses physician effort in pediatric echocardiography.