Experts in pediatric heart disease from multiple centers worldwide shared their findings at a large national conference sponsored by the Cardiac Center at Children’s Hospital of Philadelphia (CHOP). Cardiology 2018, the 21st Annual Update on Pediatric and Congenital Cardiovascular Disease, met Feb. 21 to Feb. 25 in Scottsdale, Arizona. Conference organizers honored eight clinical researchers with the Outstanding Investigator Award. The following news briefs highlight their presentations in congenital heart disease.
Frailty Measurements May Offer Clinical Tool to Assess Pediatric Cardiology Patients
The researchers assessed whether the Fried frailty phenotype, well-studied in the elderly as a measure of global infirmity, could be adapted to assess children and adolescents with significant cardiac disease.
This pilot study compared 34 pediatric heart patients with 22 age- and sex-matched healthy controls in five domains of frailty. The heart patients performed significantly worse in all five domains, specifically in the six-minute walk test, handgrip strength, body composition (height and weight), self-reported exhaustion and physical activity.
The results support the relevance of frailty phonotype to assess global infirmity in this pediatric population. Longitudinal studies should further investigate whether frailty predicts adverse health outcomes in these patients.
Chaitanya Panchangam, et al, Children’s Mercy Hospital; Translation of the Frailty Paradigm from Older Adults to Children with Cardiac Disease: A Pilot Study (abstract 63)
In Public Reporting for Pediatric Heart Surgery Outcomes, Higher Rated Programs Do Not Reflect Higher Volume or More Complex Cases
This team probed the relationship between case volume and complexity and the Star Rating system established by the Society of Thoracic Surgeons (STS) to report patient outcomes in congenital heart surgery.
Using data from the STS Congenital Heart Surgery Public Reporting website, the study team investigated case volume, mortality, and case complexity for 2013 through 2016. The STS system assigns a Star Rating to each institution based on the number of observed deaths divided by the number of expected deaths for an institution’s case mix. A 3 Star Rating implies that a center performed better than expected for its case-mix; a 1 Star Rating implies that it performed worse than expected.
The study team assessed case complexity using five categories that group procedures by risk level. When the team compared overall case volume and case complexity among 69 institutions, they found that 3 Star programs performed fewer cases, and especially fewer high-complexity cases, than did the high-volume centers.
Andrea Kennedy, et al, Children’s Hospital of Philadelphia; Relationship of Institutional Case Volume and Case Complexity to the STS Star Rating System (abstract 98)
After Fontan Surgery, Taller Patients Have Better Survival and Quality of Life
This multicenter, longitudinal study evaluated height, body mass index (BMI) and associated quality of life and exercise capacity among survivors of Fontan surgery enrolled in the Pediatric Heart Network Fontan Longitudinal Studies.
Researchers compared height and BMI, taken at 3 time points in Fontan patients, with gender specific population norms. The first-time point (F1) included 536 patients, aged 11.9 plus or minus 3.4 years; the third-time point (F3) included 362 patients aged 21.1 plus or minus 3.5 years. Fontan survivors are shorter compared to the normal population, but have similar BMI. Shorter subjects had worse survival, while survivors who were taller had better quality of life and exercise capacity compared to survivors with shorter stature. Survivors with higher BMI had lower quality of life and exercise capacity than those with lower BMI. Among Fontan patients, height was most affected in those with single right ventricles.
Linda M. Lambert, et al, University of Utah; Longitudinal Study of Anthropometry in Fontan Survivors: PHN Fontan Study (abstract 56)
Thromboelastography Testing May Help Predict Bleeding Risk in Children on ECMO
Better laboratory tools are needed to predict the risk of bleeding in children receiving extracorporeal membrane oxygenation (ECMO) for severe heart failure. Currently, adult anticoagulation guidelines are extrapolated to children, but there are age-dependent physiologic differences in hemostasis.
This single-center clinical data collection investigated the use of thromboelastography (TEG) in 40 infants supported by ECMO. TEG, currently more commonly used in adults, measures the physical properties of blood clot formation. The researchers found that TEG maximum amplitude and reaction time, along with fibrinogen concentration, can jointly predict bleeding risk in children on ECMO support. Further studies in larger samples are needed to confirm the specific thresholds identified for four risk strata.
Lynn Sleeper, et al, Boston Children’s Hospital; Thermoelastography Testing Provides Effective Risk Stratification for Bleeding in Patients on Extracorporeal Membrane Oxygenation Support (abstract 74)
Inflammatory Cytokine Levels Are High in Pleural Fluid after Fontan Surgery
Prolonged pleural drainage from chest tubes is a common complication after the Fontan procedure, and is linked to short- and long-term morbidities. This single-center cohort study was the first to measure inflammatory cytokines in pleural fluid. The study team compared 25 Fontan patients to 15 age-matched controls (bi-ventricular patients undergoing cardiopulmonary bypass).
Researchers found that inflammatory cytokines in Fontan patients’ pleural fluid increased out of proportion compared to the controls. The increased cytokine levels may perpetuate prolonged pleural drainage. Further study is needed to investigate the mechanisms of the pleural inflammatory response, and to determine whether pleural inflammation is the cause or the result of the prolonged chest tube drainage.
Stephanie Goldstein, et al, University of Michigan; Analysis of Inflammatory Cytokines in Postoperative Fontan Pleural Drainage (abstract 22)
Thoracic Duct Pressure May Be Elevated in Fontan Patients
A subset of children who undergo Fontan surgery for single-ventricle disease have rare complications in the lymphatic system that are associated with altered lymphatic circulation. This retrospective, single-center study investigated thoracic duct (TD) physiology in the setting of chronically-elevated central venous pressure.
The research team analyzed direct TD pressure measurements in 29 Fontan patients who presented for lymphatic interventions. Overall, there was a significant positive correlation between higher Fontan pressures and higher TD pressures. Individually, about half of the patients had a TD pressure that was higher than their own Fontan pressure at baseline. In addition, there was a significant increase in TD pressure and evoked pulsatility with acute TD outlet occlusion, which may have implications for outcomes in patients who undergo lymphatic interventions.
Further research should focus on the relationship between TD pressure and the severity and/or chronicity of clinical lymphatic complications. The authors recommend that follow-up studies investigate the TD pressure in Fontan patients without clinically-apparent lymphatic abnormalities.
Jill Savla, et al, Children’s Hospital of Philadelphia; Direct Measurement of Thoracic Duct Pressure in Patients with Fontan Physiology (abstract 64)
Multicenter Study Reveals Patient Outcomes, Risk Factors in Truncus Arteriosus Repair
This retrospective study performed the first known multicenter analysis of intermediate-term outcomes in children who underwent truncus arteriosus (TA) repair. The analysis included 216 children at 15 U.S. centers who had TA repair without concomitant arch obstruction from 2009-2016. Median follow-up was 2.9 years. Overall mortality was 13 percent, with the majority of deaths occurring in the first year of life. Risk factors for overall mortality were DiGeorge syndrome, preoperative mechanical ventilation, postoperative ECMO, delayed sternal closure, and postoperative infection. In this cohort, 49 percent of patients required at least one right ventricle to pulmonary artery (RV-PA) conduit intervention during the study period, frequently in early childhood. The probability of RV-PA conduit intervention was significantly higher (approximately two-fold) for aortic and pulmonary homografts than for Contegra conduits.
Jason Buckley, et al, Medical University of South Carolina; Early Childhood Outcomes Following Repair of Truncus Arteriosus: A Contemporary Multicenter Analysis (abstract 12)