Faculty Bibliography

OBJECTIVE:For infants with single ventricle malformations undergoing staged repair, interstage mortality is reported at 2% to 20%. The Single Ventricle Reconstruction trial randomized subjects with a single morphologic right ventricle undergoing a Norwood procedure to a modified Blalock-Taussig shunt (MBTS) or a right ventricle-to-pulmonary artery shunt (RVPAS). The aim of this analysis was to explore the associations of interstage mortality and shunt type, and demographic, anatomic, and perioperative factors. METHODS:Participants in the Single Ventricle Reconstruction trial who survived to discharge after the Norwood procedure were included (n = 426). Interstage mortality was defined as death postdischarge after the Norwood procedure and before the stage II procedure. Univariate analysis and multivariable logistic regression were performed adjusting for site. RESULTS:Overall interstage mortality was 50 of 426 (12%)-13 of 225 (6%) for RVPAS and 37 of 201 (18%) for MBTS (odds ratio [OR] for MBTS, 3.4; P < .001). When moderate to severe postoperative atrioventricular valve regurgitation (AVVR) was present, interstage mortality was similar between shunt types. Interstage mortality was independently associated with gestational age less than 37 weeks (OR, 3.9; P = .008), Hispanic ethnicity (OR, 2.6; P = .04), aortic atresia/mitral atresia (OR, 2.3; P = .03), greater number of post-Norwood complications (OR, 1.2; P = .006), census block poverty level (P = .003), and MBTS in subjects with no or mild postoperative AVVR (OR, 9.7; P < .001). CONCLUSIONS:Interstage mortality remains high at 12% and is increased with the MBTS compared with the RVPAS if postoperative AVVR is absent or mild. Preterm delivery, anatomic, and socioeconomic factors are also important. Avoiding preterm delivery when possible and close surveillance after Norwood hospitalization for infants with identified risk factors may reduce interstage mortality.

BACKGROUND:A major limitation of pediatric heart transplantation is scarcity of pediatric donor organs, leading to longer waiting times and higher waiting list mortality. Current practice is to match potential pediatric recipients with donors by weight; however, we hypothesize height to be a better predictor of heart size as estimated by left ventricular end-diastolic diameter (LVEDd), as well as a novel measurement from the superior vena cava-right atrium junction to inferior vena cava-right atrium junction (SVC-IVC distance). Our ultimate objective is to present a more effective means of size-matching for pediatric heart transplantation. METHODS:Measurements of LVEDd and SVC-IVC distance were taken from 254 normal echocardiograms performed on individuals aged 7 days to 22 years, and correlated with demographic variables, including height, weight, and body surface area. Simulations were conducted using echocardiographic measurements and size parameters of past recipients with hypothetic donors to demonstrate practicality. RESULTS:There was a linear relationship between height and SVC-IVC distance (R(2) = 0.904) and LVEDd (R(2) = 0.889), whereas the relationships with weight were logarithmic (SVC-IVC distance, R(2) = 0.855; LVEDd, R(2) = 0.880), and the relationships with body surface area were polynomial (SVC-IVC distance, R(2) = 0.880; LVEDd, R(2) = 0.884). Three simulations demonstrate improvements in efficiency of the size-matching process. CONCLUSIONS:The use of height and a novel SVC-IVC distance measurement to evaluate heart size in potential pediatric heart transplant recipients and donors may allow for broadening of the donor pool and creation of a more efficient and accurate size-matching process. The prospective evaluation of these novel methods with respect to clinical outcomes is necessary.

Left-ventricular noncompaction (LVNC) is an echocardiographic finding of increasing frequency in pediatrics; however, predictors of outcomes have been difficult to identify. We conducted a retrospective review of pediatric patients at the Morgan Stanley Children's Hospital of New York from January of 1993 to September of 2009 to identify predictors of the primary outcome of death or heart transplantation. LVNC was identified in 50 patients, 34 of them < 1 year of age. Death or transplantation occurred in 26 patients, with a median survival of 1.17 years after presentation. Patients surviving 1 year after presentation had 75% conditional survival, and patients surviving 2 years after presentation had 92% conditional survival. Hemodynamic instability, poor ventricular function, and LV dilatation were each independent predictors of poor outcome. Of the 21 patients who presented with hemodynamic instability, 17 died or underwent transplantation at a median of 0.08 years after presentation. In conclusion, LVNC is recognized more in younger patients; however, age is not a predictor of outcome. Patients who present with hemodynamic instability and poor ventricular function have decreased transplant-free survival, and most poor outcomes occur within the first year after presentation. Therefore, early listing for transplant may lead to better outcomes in this population.

We assessed the association of socioeconomic (SE) position with graft loss in a multicenter cohort of pediatric heart transplant (HT) recipients. We extracted six SE variables from the US Census 2000 database for the neighborhood of residence of 490 children who underwent their primary HT at participating transplant centers. A composite SE score was derived for each child and four groups (quartiles) compared for graft loss (death or retransplant). Graft loss occurred in 152 children (122 deaths, 30 retransplant). In adjusted analysis, graft loss during the first posttransplant year had a borderline association with the highest SE quartile (HR 1.94, p = 0.05) but not with race. Among 1-year survivors, both black race (HR 1.81, p = 0.02) and the lowest SE quartile (HR 1.77, p = 0.01) predicted subsequent graft loss in adjusted analysis. Among subgroups, the lowest SE quartile was associated with graft loss in white but not in black children. Thus, we found a complex relationship between SE position and graft loss in pediatric HT recipients. The finding of increased risk in the highest SE quartile children during the first year requires further confirmation. Black children and low SE position white children are at increased risk of graft loss after the first year.