Emily A. Bullock

Would access to device therapies improve transplant outcomes for adults with congenital heart disease? Analysis of the United Network for Organ Sharing (UNOS)

BACKGROUND Patients with congenital heart disease (CHD) now survive into adulthood and often present with end-stage heart failure (HF). HF management and approach to orthotopic heart transplant (OHT) may differ from adults without CHD. We sought to compare OHT waitlist characteristics and outcomes for these 2 groups. METHODS The Organ Procurement and Transplantation Network (OPTN)/United Network for Organ Sharing (UNOS) database was used to identify adults (≥18 years) listed for OHT from 2005 to 2009. The cohort was divided into those with or without CHD. RESULTS Of 9,722 adults included, 314 (3%) had CHD. Adults with CHD were younger (35 ± 13 vs 52 ± 12 years, p < 0.01) and more often had undergone prior cardiac surgery (85% vs. 34%, p < 0.01). Patients with CHD were less likely to have a defibrillator (44% vs 75%, p < 0.01) or ventricular assist device (5% vs 14%, p < 0.01) and were more likely to be listed at the lowest urgency status than patients without CHD (64% vs 44%, p < 0.01). Fewer CHD patients achieved OHT (53% vs 65%, p < 0.001). Although overall waitlist mortality did not differ between groups (10% vs 8%, p = 0.15), patients with CHD were more likely to experience cardiovascular death (60% vs 40%, p = 0.03), including sudden in 44% and due to HF in 16%. CONCLUSIONS Despite lower urgency status, patients with CHD have greater cardiovascular mortality awaiting OHT than those without. Increased defibrillator use could improve survival to OHT, because sudden death is common. VAD support may benefit select patients, but experience in CHD is limited. Referral to specialized adult congenital heart centers can enhance utilization of device therapies and potentially improve waitlist outcomes.

Early survival after heart transplant in young infants is lowest after failed single-ventricle palliation: A multi-institutional study

BACKGROUND Infant heart transplant (HT) recipients have the best long-term survival of any age group, but the small donor pool and high early mortality limit the therapeutic effectiveness. We sought to determine the relationship between pre-HT diagnosis and early HT outcome to better define the mortality risk associated with a diagnosis of congenital heart disease (CHD) and to examine differences between early and current HT eras. METHODS The Pediatric Heart Transplant Study (PHTS) database was used to identify 739 infant HT recipients at age ≤ 6 months between 1993 and 2008 divided into the following etiologic groups: cardiomyopathy (CM), 18%; hypoplastic left heart syndrome (HLHS) without surgery, 41%; HLHS with surgery, 9%; other CHD without surgery, 16%; and other CHD with surgery, 15%. Severity of illness at HT, post-HT survival, and era effects were compared. RESULTS At 1 year after HT, survival was 89% for the CM group, which was the best, 79% for CHD without surgery, 82% for CHD with surgery, 79% for HLHS without surgery, and 70% for HLHS with surgery, which was the worst outcome. Hazard function analysis demonstrated the difference occurred within the first 3 months after HT. After adjusting for illness severity, differences in mortality risk persisted across etiologic groups. HT survival was similar in the current surgical era for HLHS with surgery, 71% (1993-1998) vs 70% (1999-2008). CONCLUSIONS Infant HT recipients with different pre-HT diagnoses have significantly different post-HT outcomes. HLHS infants with surgery have the lowest survival and their outcome is unchanged in the current era.

Rejection with hemodynamic compromise in the current era of pediatric heart transplantation: a multi-institutional study.

BACKGROUND Survival after pediatric heart transplant has improved over time, as has the incidence of overall rejection. We studied the effect of era on the occurrence and outcome of rejection with hemodynamic compromise (HC). METHODS Data from 2227 patients who received allografts between 1993 and 2006 at 36 centers in the Pediatric Heart Transplant Study were analyzed to determine incidence, outcome, and risk factors for rejection with HC in early (1993-1999) and recent (2000-2006) eras. Rejection with HC was classified as severe (RSHC) when inotropes were used for circulatory support and mild (RMHC) when inotropes were not used. RESULTS Of 1217 patients with any episode of rejection, 541 had rejection with HC. Freedom from RMHC improved at 1 year (81% vs 90%, p < 0.001) and at 5 years (74% vs 85%, p < 0.001) in the early vs recent eras, but freedom from RSHC was similar between eras (93% vs 95% at 1 year and 85% vs 87% at 5 years, p = 0.24). Survival after RSHC (63% at 1 year and 49% at 5 years) was worse than after RMHC (87% at 1 year and 72% at 5 years, p < 0.001) and did not change over time. Risk factors for RSHC were non-white race (hazard ratio [HR], 1.73; 95% confidence interval [CI], 1.29-2.32, p < 0.01), older age (HR, 2.85; 95% CI, 1.24-6.53; p = 0.01), and non-A blood type (HR, 1.51;, 95% CI, 1.11-2.04,; p = 0.01), but the only risk factor for RMHC was earlier era of transplant (HR, 1.94; 95% CI, 1.56-2.41; p < 0.001). CONCLUSIONS The incidence of RMHC has declined over time but the same era effect has not occurred with RSHC. Close follow-up after RSHC is crucial because mortality is so high.

Effect of ABO-Incompatible Listing on Infant Heart Transplant Waitlist Outcomes: Analysis of the United Network for Organ Sharing (UNOS) Database

BACKGROUND Midterm heart transplant outcomes of ABO-incompatible (ABO-I) organ use in infants are favorable. ABO-I transplantation has resulted in reduced waitlist mortality in some countries. This study assessed the effect of an ABO-I listing strategy on pre-transplant outcomes in the United States. METHODS The Organ Procurement and Transplantation Network (OPTN)/United Network of Organ Sharing (UNOS) database was used to identify infants aged younger than 1 year listed as status 1 for heart transplantation between January 1, 2001, and May 20, 2008. The cohort was divided into 2 groups: eligible for ABO-compatible (ABO-C) transplant and eligible for ABO-I transplant. Baseline characteristics, waitlist times, and outcomes were compared in univariate analysis. Competing risks analysis evaluated differences in time to transplant in the presence of other outcomes. RESULTS Of 1,029 infants listed for transplant, 277 (27%) were listed for an ABO-I transplant. Overall, 92% of transplant recipients received an ABO-C organ regardless of listing type. Among recipients eligible for ABO-I, only 27% received an ABO-I organ. The percentage that underwent transplant in each group did not differ. Although infants listed for an ABO-I organ had a shorter wait time for transplant, waitlist mortality was similar. CONCLUSIONS Despite the intended merits of ABO-I heart transplantation, ABO-I listing and organ acceptance have not yielded lower waitlist mortality in the United States under the current UNOS allocation algorithm. Consideration should be given to altering the allocation system to one that gives less preference toward blood group compatibility in hopes of improving organ use and reducing waitlist mortality.

Efficacy of 100 consecutive right ventricular endomyocardial biopsies in pediatric patients using the right internal jugular venous approach

SummaryIndications for endomyocardial biopsy (EMB) in pediatric patients include cardiomyopathy and postheart transplant rejection surveillance. There have been few reports of the use of the internal jugular venous approach for right ventricular EMB in pediatric patients. In this study, we report our experience with 100 consecutive EMBs in pediatric patients using this approach. Indications for EMB were cardiomyopathy of unknown etiology in four patients, adriamycin cardiomyopathy in three patients, postheart transplant rejection surveillance in five patients, right ventricular outflow tract tumors in one patient, and sustained ventricular tachycardia in one patient. Histologic diagnoses of biopsy specimens included interstitial fibrosis, vasculopathy, hypertrophy, anthracycline cardiotoxicity, and various degrees of allograft rejection. All EMBs were performed successfully and without complications. We conclude that right ventricular EMB using the right internal jugular venous approach can be performed safely and successfully in pediatric patients as young as 2 months of age and repeatedly in patients as young as 8 years old.

Pulmonary vascular remodelling after heart transplantation in patients with cavopulmonary connection

OBJECTIVES Pulmonary vascular resistance (PVR) after heart transplantation (HT) is an important predictor of postoperative outcomes. We hypothesize that PVR and pulmonary capillary wedge pressure (PCWP) will exhibit favourable pulmonary vascular remodelling in patients with failing cavopulmonary connection (CPC) after HT. METHODS Retrospective analysis of patients with superior CPC (SCPC) and total CPC (TCPC) who have undergone HT was performed. Patient data, including age, underlying congenital heart defect, timing of CPC surgery and timing of HT, were reviewed. Right heart catheterization data, including PCWP (mmHg) and PVR indexed (PVRi, Woods Units) from preoperative, at 1 month, 6 months and 12 months after HT, were collected. Paired data were analysed using Students t-test. RESULTS Among 21 patients with failing CPC who underwent HT, 10 had SCPC and 11 had TCPC. Average age at HT was 13.3 ± 8 years. Average time after CPC to HT was 8.5 ± 6.2 years. PVRi was noted to trend down over time after HT (PVRi pre-HT versus 6 months after HT, 2.75 vs 2.06, P = 0.06 and pre-HT versus 12 months after HT, 2.79 vs 2.27, P = 0.09). There was a statistically significant decrease in PCWP at 6 months (pre-HT versus 6 months after HT, 12.6 vs 10.8, P = 0.01) and 12 months (pre-HT versus 12 months after HT, 12.9 vs 10.1, P = 0.01) after HT. CONCLUSIONS Pulmonary vascular changes occur gradually after HT in patients with CPC similar to those shown after HT in patients with cardiomyopathy. However, larger studies are needed to investigate correlation between outcomes and the presence or absence of pulmonary vascular changes after HT in CPC patients.

Etiology and Outcome of Outpatient Fevers in Pediatric Heart Transplant Patients

We reviewed 74 outpatient febrile episodes in 22 pediatric heart transplant patients in order to determine etiologies, rates of serious and nonserious illness, and factors predictive of serious disease. Twenty-two febrile episodes (30%) resulted in hospital admission. Only three variables were predictive of serious illness: longer duration of fever, shorter time since transplant, and lower febrile episode number. We conclude that at least 70% of outpatient febrile episodes are nonserious and can be managed safely in an outpatient setting. The duration of fever may be predictive of serious disease but is not useful at initial presentation.