Risk Factors and Outcome of Fontan‐Associated Plastic Bronchitis: A Case‐Control Study

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139068/1/jah3521.pd

26th Annual Computational Neuroscience Meeting (CNS*2017): Part 3 - Meeting Abstracts - Antwerp, Belgium. 15–20 July 2017

This work was produced as part of the activities of FAPESP Research,\ud Disseminations and Innovation Center for Neuromathematics (grant\ud 2013/07699-0, S. Paulo Research Foundation). NLK is supported by a\ud FAPESP postdoctoral fellowship (grant 2016/03855-5). ACR is partially\ud supported by a CNPq fellowship (grant 306251/2014-0)

Abstract 16855: Left Ventricular Volumes, Stress, and Strain in Normal Children and Young Adults Measured by 3-Dimensional Echocardiography

Background: 3D echocardiography (3DE) is increasingly being used clinically to calculate ventricular volumes and function. Normal pediatric values of 3D LV volumes and strain are not well established; moreover, there are no reports of the stress-strain relationship (an index of contractility) based upon 3D technology in this cohort. Methods: 3D LV datasets were obtained as part of routine echocardiographic examinations in eligible pediatric patients (≤ 21 years of age) between January 2014 and March 2015. Included patients had structurally normal hearts. Exclusion criteria included non-cardiac disorders with a potential impact on ventricular function and family history of cardiomyopathy. Image acquisition was performed using the Philips IE33 with X3/5/7 probes. Strain (3D; circumferential, GCS; and longitudinal, GLS) was analyzed according to a commercial 3D speckle-tracking analysis package (4D LV Analysis 3.1; Tomtec). LV mid-wall global average stress was calculated from the 3D LV volumes and 2D cross-sectional area/long-axis dimensions. Results: 237 patients were included (age= 0.2 mo-21 y). The correlation between 3D and 2D LV mass and volumes was excellent (mass, R=0.94; end-diastolic volume, R=0.94; end-systolic volume, R=0.90; p&lt;0.001 for all). Mean+-SD strain values (%) were: 3D=-33.9±2.8; GCS=-28.0 ± 3.1; GLS=-20.7 ± 3.0; only GLS varied significantly with age (R=0.26; p&lt;0.001). Overall, 3D strain was inversely linearly related to wall stress (R=0.26; p&lt;0.001); the strongest relationship was present in patients from age 0-5 years (R=0.48; p&lt;0.01). When normalized to stress, absolute LV strain decreased with age (Figure 1: R=0.33; p&lt;0.001). Conclusions: 3DE may be used to calculate LV stress, strain, and volume parameters. Among strain parameters, age-related changes were seen only in GLS. Examination of the stress-strain relationship using these techniques may yield new insights into maturational changes in myocardial contractility. </jats:p

Abstract 15785: The Natural History of Doppler-Derived Left Ventricular Outflow Tract Gradients in Patients With Congenital Valvar Aortic Stenosis Before and After Balloon Valvuloplasty

Introduction: Congenital aortic stenosis (AS) has been reported to manifest a slow rate of progression in mild disease with a greater likelihood of progression in patients with moderate-severe disease. The natural history of the Doppler estimated peak gradient (DEPG) in patients after balloon aortic valvuloplasty (BAV) has not previously been studied on a large scale. Methods: A retrospective review was performed of 360 patients from 1984-2012 with AS providing a total of 2051 echocardiograms before and after BAV. Patients were excluded if they had an intervention within the first 30 days of life. The relationships between the AS DEPG and several predictors (age at time of initial echocardiogram, valve morphology, and history of intervention) were explored using linear mixed effect models. The DEPG slope was then calculated in patients who had at least 2 echocardiograms before and after balloon dilation using linear regression modeling. Results: The rate of increase in the DEPG for all patients with AS was 5.6 mmHg per 10 years of age (p&lt;0.001). The DEPG increased over time regardless of age at presentation with the greatest mean increase in patients presenting from 10-14.9 years (n=59; 11.9 mmHg per 10 years; p&lt;0.001). Patients who went on to have a BAV or surgical intervention on the aortic valve had a significantly higher rate of AS progression than the overall patient cohort (n=59; 18.0 mmHg/10 years and n=36; 13.1 mmHg/10 years). Patients with a unicommissural (n=39) aortic valve had a significantly higher rate of progression compared to those with a bicommissural (n=270) aortic valve (8.1 mmHg/10 years and 4.5 mm Hg/10 years; p&lt;0.001). The median rate of progression in the post-BAV group was significantly lower than the median pre-BAV rate of progression (n=34; pre-BAV 3.97 (1.69-8.7) mmHg/year; post-BAV 0.40 (-1.80-3.88) mmHg/year; p&lt;0.01). Conclusions: The DEPG of native valve congenital aortic stenosis shows a slow, linear rate of progression prior to intervention. The rate of progression is significantly higher in patients with a unicommissural aortic valve as well as those patients that go on to have a BAV and/or surgical intervention. The rate of the DEPG progression is significantly lower after BAV. </jats:p

Cell Saver Blood Reinfusion Up to 24 Hours Post Collection in Pediatric Cardiac Surgical Patients Does Not Increase Incidence of Hospital-Acquired Infections or Mortality

Cell saver blood reinfusion, a blood conservation technique recently available for pediatric use, is typically limited to 6 hours post processing to guard against bacterial contamination. We hypothesize that reinfusion of cell saver blood up to 24 hours post collection in children after cardiac surgery will not increase the incidence of hospital-acquired infections (HAI). The primary aim is to compare incidence of HAI between children receiving cell saver blood ≤6 hours vs. >6 to ≤24 hours from its collection. The secondary aim is to compare mortality and clinical outcomes. Retrospective chart review of children ≤18 years undergoing cardiac surgery with cardiopulmonary bypass (CPB) from 2013 to 2018 when cell saver collection and bedside temperature controlled storage became standard of care. Patients on extracorporeal membrane oxygenation (ECMO) within 48 hours postoperatively and those who did not receive cell saver were excluded. The primary outcome was HAI incidence postoperative days 0–6. Demographic data included diagnosis, surgical severity score, and clinical outcomes. 466 patients, 45% female. No significant between-group differences identified. There was no significant difference in HAI (control 8.5% vs. treatment 8.0%, p = .80) and death (control 7.9% vs. treatment 4.9%, p = .20). Noninferiority testing indicated the treatment group was not statistically inferior to the control group (p = .0028). Kaplan–Meier curve depicted similar status between-group rates of no infection or death; 92% treatment vs. 91% control. Total volume allogeneic red blood cell transfusion (allogeneic blood transfusion [ABT]) up to 24 hours postoperatively was significantly less in the treatment group, p 6 to ≤24 hours post collection. Treatment subjects received significantly less volume of ABT. Considering the risks of ABT, these findings support cell saver blood reinfusion up to 24 hours post collection

Abstract 9566: Quantification of Valve Regurgitation in the Pediatric Population Using 3-Dimensional Echocardiography: Feasibility and Comparison With Cardiac Magnetic Resonance Imaging

Introduction: Valvar regurgitation in pediatric patients is commonly assessed by cardiac magnetic resonance (CMR). This modality is associated with increased cost and need for anesthesia in young patients when compared to echocardiography. 3-dimensional echocardiography (3DE) can measure ventricular volumes and calculate the regurgitation fraction (RF) by comparison of stroke volumes - similar to CMR. Given the potential advantages of 3DE in children, this study sought to compare the quantification of single valvar regurgitation using 3DE versus CMR as the gold standard. Methods: Pediatric patients ≤18 years of age were included in the study. Patients were excluded if they had more than mild regurgitation of an additional valve, significant shunt, or suboptimal imaging windows. Full volume data sets were obtained sub-costally using a Philips IE33 or EPIQ CVx machine (X5 or X7 ultrasound probe). 3DE volumes were analyzed using 4D Cardioview (Tomtec Imaging Systems) and compared with ventricular volumes and RF obtained by CMR. Inter- and intra-observer reliability were assessed for 3DE ventricular volumes and RF. Results: 34 patients had volumes obtained by 3DE and CMR with two patients having pairs of studies performed on different dates. The median age was 8.7 (IQR; 3.9-12.3) years. 12 studies (33%) were obtained under sedation. Primary valve involvement was: mitral-12 (33%), tricuspid-9 (25%), pulmonary-1 (3%), and aortic-14 (39%). Agreement between 3DE and CMR ventricular volumes by intraclass correlation coefficient (ICC) was excellent (ICC&gt;0.90). Agreement for the regurgitant fraction was good (ICC 0.80 (95% CI; 0.68, 0.88)). Ventricular volume ratios obtained by MRI and 3DE were strongly correlated; Spearman r = 0.92 (95% CI; 0.85-0.96). Inter-observer reliability was excellent for ventricular volumes and moderate for RF (ICC 0.63 (95% CI; 0.23, 0.85)). Intra-observer reliability was excellent for ventricular volumes and RF (ICC≥0.97). Conclusions: Assessment of single valvar regurgitation using 3DE compares favorably with CMR in pediatric patients. The shorter time for image acquisition and lower cost will allow for standard application of 3DE to measure single valve regurgitation in this population, particularly on a serial basis. </jats:p