Impact of ventricular assist device use on pediatric heart transplant waitlist mortality: Analysis of the scientific registry of transplant recipients database.

BACKGROUND: Children awaiting heart transplant (Tx) have a high risk of death due to donor organ scarcity. Historically, ventricular assist devices (VADs) reduced waitlist mortality, prompting increased VAD use. We sought to determine whether the VAD survival benefit persists in the current era. METHODS: Using the Scientific Registry of Transplant Recipients, we identified patients listed for Tx between 3/22/2016 and 9/1/2020. We compared characteristics of VAD and non-VAD groups at Tx listing. Cox proportional hazards models were used to identify risk factors for 1-year waitlist mortality. RESULTS: Among 5054 patients, 764 (15%) had a VAD at Tx listing. The VAD group was older with more mechanical ventilation and renal impairment. Unadjusted waitlist mortality was similar between groups; the curves crossed ~90 days after listing (p = .55). In multivariable analysis, infant age (HR 2.77, 95%CI 2.13-3.60), Black race (HR 1.57, 95%CI 1.31-1.88), congenital heart disease (HR 1.23, 95%CI 1.04-1.46), renal impairment (HR 2.67, 95%CI 2.19-3.26), inotropes (HR 1.28, 95%CI 1.09-1.52), and mechanical ventilation (HR 2.23, 95%CI 1.84-2.70) were associated with 1-year waitlist mortality. VADs were not associated with mortality in the first 90 waitlist days but were protective for those waiting ≥90 days (HR 0.43, 95%CI 0.26-0.71). CONCLUSIONS: In the current era, VADs reduce waitlist mortality, but only for those waitlisted ≥90 days. The differential effect by race, size, and VAD type is less clear. These findings suggest that Tx listing without VAD may be reasonable if a short waitlist time is anticipated, but VADs may benefit those expected to wait >90 days.

Outcomes after initial heart failure consultation in Fontan patients.

BACKGROUND: Patients with Fontan failure are high-risk candidates for heart transplantation and other advanced therapies. Understanding the outcomes following initial heart failure consultation can help define appropriate timing of referral for advanced heart failure care. METHODS: This is a survey study of heart failure providers seeing any Fontan patient for initial heart failure care. Part 1 of the survey captured data on clinical characteristics at the time of heart failure consultation, and Part 2, completed 30 days later, captured outcomes (death, transplant evaluation outcome, and other interventions). Patients were classified as "too late" (death or declined for transplant due to being too sick) and/or "care escalation" (ventricular assist device implanted, inotrope initiated, and/or listed for transplant), within 30 days. "Late referral" was defined as those referred too late and/or had care escalation. RESULTS: Between 7/2020 and 7/2022, 77 Fontan patients (52% inpatient) had an initial heart failure consultation. Ten per cent were referred too late (6 were too sick for heart transplantation with one subsequent death, and two others died without heart transplantation evaluation, within 30 days), and 36% had care escalation (21 listed ± 5 ventricular assist device implanted ± 6 inotrope initiated). Overall, 42% were late referrals. Heart failure consultation < 1 year after Fontan surgery was strongly associated with late referral (OR 6.2, 95% CI 1.8-21.5, p=0.004). CONCLUSIONS: Over 40% of Fontan patients seen for an initial heart failure consultation were late referrals, with 10% dying or being declined for transplant within a month of consultation. Earlier referral, particularly for those with heart failure soon after Fontan surgery, should be encouraged.

Impaired ventilation during 6-min walk test in congenital central hypoventilation syndrome.

BACKGROUND: Patients with congenital central hypoventilation syndrome (CCHS) can develop hypoxemia and hypercapnia during exercise. However, there is limited literature on cardiorespiratory responses during submaximal exercise and their correlation with paired-like homeobox 2B (PHOX2B) genotype. OBJECTIVES: To assess oxygen saturation (SpO2 ), end-tidal carbon dioxide (ETCO2 ), heart rate (HR), and 6-min walk distance (6MWD) during a 6-min walk test (6MWT) in CCHS subjects and to correlate them with PHOX2B genotypes and assisted ventilation (AV) via tracheostomy. METHODS: In this cross-sectional study, subjects with CCHS performed 6MWT with continuous pulse oximetry, HR, and capnography recorded before and during the 6MWT. Medical records were reviewed for PHOX2B genotype and phenotype data. Patients were categorized based on PHOX2B genotype and AV via tracheostomy. RESULTS: Fifteen subjects aged 10.5 (interquartile range 7.9-16.2) years completed the 6MWT. Nine subjects used AV via tracheostomy. Seven (47%) subjects developed hypoxemia (SpO2 ≤ 90%, n = 7) and hypoventilation (ETCO2 ≥ 50 mmHg, n = 3) during the 6MWT. There was a significant decline from baseline SpO2 , increase from baseline ETCO2 , and increase in HR during the 6MWT (all p < 0.05). Subjects had decreased median percent predicted 6MWD (59.7% [50.6%-62.5%]). Nadir SpO2 (p = 0.029) and peak ETCO2 (p = 0.046) differed significantly between PHOX2B genotype groups but 6MWD did not (p = 0.8). CONCLUSION: Despite normal oxygenation and ventilation at rest and during sleep on AV, patients with CCHS can develop hypoxemia and hypercapnia during submaximal exercise. Our study highlights the importance of assessing ventilatory responses during submaximal exercise in patients with CCHS regardless of their PHOX2B genotype.

Relationship of ventricular assist device support duration with pediatric heart transplant outcomes.

BACKGROUND: There is wide variability in the timing of heart transplant (HTx) after pediatric VAD implant. While some centers wait months before listing for HTx, others accept donor heart offers within days of VAD surgery. We sought to determine if HTx within 30 days versus ≥ 30 after VAD impacts post-HTx outcomes. METHODS: Children on VAD pre-HTx were extracted from the Pediatric Heart Transplant Study database. The primary endpoints were post-HTx length of hospital stay (LOS) and one-year survival. Confounding was addressed by propensity score weighting using inverse probability of treatment. Propensity scores were calculated based on age, blood type, primary cardiac diagnosis, decade, VAD type, and allosensitization status. RESULTS: A total of 1064 children underwent VAD prior to HTx between 2000 to 2018. Most underwent HTx ≥ 30 days post-VAD (70%). Infants made up 22% of both groups. Patients ≥ 12 years old were 42% of the < 30 days group and children 1 to 11 years comprised 47% of the ≥ 30 days group (p < 0.001). There was no difference in the prevalence of congenital heart disease vs. cardiomyopathy (p = 0.8) or high allosensitization status (p = 0.9) between groups. Post-HTx LOS was similar between groups (p = 0.11). One-year survival was lower in the < 30 days group (adjusted mortality HR 1.76, 95% CI 1.11-2.78, p = 0.016). CONCLUSIONS: A longer duration of VAD support prior to HTx is associated with a one-year survival benefit in children, although questions of patient complexity, post-VAD complications and the impact on causality remain. Additional studies using linked databases to understand these factors will be needed to fully assess the optimal timing for post-VAD HTx.

A preliminary investigation of sleep quality and patient-reported outcomes in pediatric solid organ transplant candidates.

The current cross-sectional, single-center study aimed to examine sleep quality in a sample of adolescents awaiting solid organ transplantation and to explore associations between sleep quality and both health-related quality of life and barriers to adherence. Thirty adolescents between the ages of 12 and 18 years (M age = 15.26, SD = 1.89) who were awaiting transplantation participated in this study. Participants completed measures of sleep quality, health-related quality of life, and barriers to adherence. T test and correlational analyses were performed to examine study aims. Adolescents awaiting transplantation had significantly lower levels of overall sleep quality compared to published norms of healthy peers. Domains of sleep quality were positively related to emotional and psychosocial health-related quality of life. Sleep quality domains were also negatively related to adherence barriers. This study provides preliminary evidence demonstrating that sleep quality among transplant candidates is compromised, and that poor sleep quality is related to adolescents' functioning across a number of domains during the pretransplant period. Results highlight the clinical importance of assessing and targeting sleep functioning in adolescents awaiting transplantation in order to reduce the negative influence of suboptimal sleep on functioning during this vulnerable period.

Breastfeeding practices in military families: a 12-month prospective population-based study in the national capital region.

Breastfeeding practices in military families have not been widely investigated. The objective of this study was to measure the prevalence and duration of breastfeeding among uniformed families and identify factors associated with breastfeeding. We conducted a prospective study of 253 mothers of new infants from July to December 2004. Initial information gathered included demographic data, feeding choices, and intended duration of breastfeeding. Follow-up surveys were conducted until 12 months postpartum. 51% of mothers were breastfeeding at 6 months and 25% at 1 year. Mothers on active duty were equally likely to breastfeed than non-active duty mothers. Officer mothers were 3 times more likely to breastfeed compared to enlisted mothers (p = 0.005). Mothers with higher education were twice as likely to breastfeed longer (p = 0.015). Families participating in Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) were 2.5 times less likely to breastfed at 1 year (p < 0.001). Our study shows a higher percentage of women initiating and maintaining breastfeeding compared to national data, but still less than current American Academy of Pediatrics guidelines. Our study suggests that to improve breastfeeding rates among uniformed families, more attention may need to be directed to younger, enlisted mothers and those families in a lower socioeconomic status or receiving WIC assistance.

Left ventricular noncompaction: a rare cause of hydrops fetalis.

We present a case of isolated left ventricular noncompaction (LVNC), a severe congenital cardiomyopathy, which presented in the neonatal period as fetal hydrops. To our knowledge, this is the first child with LVNC presenting with hydrops fetalis to survive infancy. Once considered a uniformly fatal and extremely rare form of cardiomyopathy, LVNC has recently been shown to be more common than previously reported, with a varying range of clinical severity. Although long-term morbidity and mortality are not clearly known, recent work suggests better survivability than once reported.