Incidence and risk factors for mortality in infants awaiting heart transplantation in the USA

Management of children with dilated cardiomyopathy in The Netherlands: Implications of a low early transplantation rate

BACKGROUND

The policy for listing and transplant for children with dilated cardiomyopathy (DCM) in The Netherlands has been conservative because of low donor availability. The effects of this policy on outcome are reported.

METHODS

This was a multicenter, nationwide study performed in 148 children with DCM. The primary outcome was death or heart transplant.

RESULTS

Overall, 43 patients (29%) died or were transplanted. Within 1 year of diagnosis, 21 patients died, and only 4 underwent transplantation (3 on mechanical circulatory support). The 1-year survival was 85% (95% confidence interval [CI] = 79-91), and 5-year survival was 84% (95% CI = 78-90). Transplantation-free survival at 1 year was 82% (95% CI = 75-88) and at 5 years was 72% (95% CI = 64-80). Within 1 year of diagnosis, with death as the main end-point (21 of 25, 84%), intensive care unit admission (hazard ratio = 2.6, p = 0.05) and mechanical circulatory support (hazard ratio = 3.2, p = 0.03) were risk factors (multivariable Cox analysis); inotropic support was longer in patients reaching an end-point. At >1 year after diagnosis, with transplantation as the main end-point (15 of 18, 83%), age >6 years (hazard ratio = 6.1, p = 0.02) was a risk factor. There were 56 (38%) children who recovered, 50% within 1 year of diagnosis. Recovery was associated with younger age; was similar in patients with myocarditis (43%) and idiopathic disease (41%); and was similar in patients initially admitted to the intensive care unit, admitted to the ward, or treated as outpatients.

CONCLUSIONS

The transplantation rate in our cohort in the first year was low, with 1-year and 5-year survival rates similar to other cohorts. Our results suggest that a conservative approach to list children for transplantation early after presentation may be justifiable except for patients with prolonged intensive care unit or mechanical circulatory support.

Community socioeconomic disadvantage and the survival of infants with congenital heart defects

OBJECTIVES

We examined the association between survival of infants with severe congenital heart defects (CHDs) and community-level indicators of socioeconomic status.

METHODS

We identified infants born to residents of Arizona, New Jersey, New York, and Texas between 1999 and 2007 with selected CHDs from 4 population-based, statewide birth defect surveillance programs. We linked data to the 2000 US Census to obtain 11 census tract-level socioeconomic indicators. We estimated survival probabilities and hazard ratios adjusted for individual characteristics.

RESULTS

We observed differences in infant survival for 8 community socioeconomic indicators (P < .05). The greatest mortality risk was associated with residing in communities in the most disadvantaged deciles for poverty (adjusted hazard ratio [AHR] = 1.49; 95% confidence interval [CI]  = 1.11, 1.99), education (AHR = 1.51; 95% CI = 1.16, 1.96), and operator or laborer occupations (AHR = 1.54; 95% CI = 1.16, 1.96). Survival decreased with increasing numbers of indicators that were in the most disadvantaged decile. Community-level mortality risk persisted when we adjusted for individual-level characteristics.

CONCLUSIONS

The increased mortality risk among infants with CHDs living in socioeconomically deprived communities might indicate barriers to quality and timely care at which public health interventions might be targeted.

Pediatric heart transplantation-indications and outcomes in the current era

Pediatric heart transplantation (HTx) remains an important treatment option in the care of children with end-stage heart disease, whether it is secondary to cardiomyopathy or congenital heart disease (CHD). As surgical outcomes for CHD have improved, the indications for pediatric HTx have had to be dynamic, not only for children with CHD but also for the growing population of adults with CHD. As the field of pediatric HTx has evolved, the outcomes for children undergoing HTx have improved. This is undoubtedly due to the continued research efforts of both single-center studies, as well as research collaboratives such as the International Society for Heart and Lung Transplantation (ISHLT) and the Pediatric Heart Transplant Study (PHTS) group. Research collaboratives are increasingly important in pediatric HTx as single center studies for a limited patient population may not elicit strong enough evidence for practice evolution. Similarly, complications that limit the long term graft survival may occur in a minority of patients thus pooled experience is essential. This review focuses on the indications and outcomes for pediatric HTx, with a special emphasis on studies generated by these research collaboratives.

Pediatric heart transplantation-indications and outcomes in the current era

Pediatric heart transplantation (HTx) remains an important treatment option in the care of children with end-stage heart disease, whether it is secondary to cardiomyopathy or congenital heart disease (CHD). As surgical outcomes for CHD have improved, the indications for pediatric HTx have had to be dynamic, not only for children with CHD but also for the growing population of adults with CHD. As the field of pediatric HTx has evolved, the outcomes for children undergoing HTx have improved. This is undoubtedly due to the continued research efforts of both single-center studies, as well as research collaboratives such as the International Society for Heart and Lung Transplantation (ISHLT) and the Pediatric Heart Transplant Study (PHTS) group. Research collaboratives are increasingly important in pediatric HTx as single center studies for a limited patient population may not elicit strong enough evidence for practice evolution. Similarly, complications that limit the long term graft survival may occur in a minority of patients thus pooled experience is essential. This review focuses on the indications and outcomes for pediatric HTx, with a special emphasis on studies generated by these research collaboratives.

Pediatric heart allocation and transplantation in Eurotransplant

Pediatric heart allocation in Eurotransplant (ET) has evolved over the past decades to better serve patients and improve utilization. Pediatric heart transplants (HT) account for 6% of the annual transplant volume in ET. Death rates on the pediatric heart transplant waiting list have decreased over the years, from 25% in 1997 to 18% in 2011. Within the first year after listing, 32% of all infants (<12 months), 20% of all children aged 1-10 years, and 15% of all children aged 11-15 years died without having received a heart transplant. Survival after transplantation improved over the years, and in almost a decade, the 1-year survival went from 83% to 89%, and the 3-year rates increased from 81% to 85%. Improved medical management of heart failure patients and the availability of mechanical support for children have significantly improved the prospects for children on the heart transplant waiting list.

Risk factors for mortality or delisting of patients from the pediatric heart transplant waiting list

OBJECTIVE

Current literature assessing factors associated with outcomes of patients waiting for pediatric heart transplants has focused on survival to transplant and mortality. Our aim was to determine risk factors associated with the outcomes of delisting, transplant, or death while waiting.

METHODS

In this single-center, retrospective study of patients listed for heart transplants, competing risk analysis was used to model survival from listing to 4 competing outcomes (transplant, death, delisting for clinical deterioration, delisting for clinical improvement or surgical intervention).

RESULTS

There were 308 listing episodes in 280 patients. In competing risk analysis, 11% remained listed at 6 months (transplant 62%, dead 13%, delisted worse 6%, delisted improved 8%). Extracorporeal membrane oxygenation and ventricular assist devices were associated both with higher probability of transplant (hazard ratio [HR], 2.8; P < .001) and delisting for clinical deterioration (HR, 2.7; P = .06). Younger age at listing and complex congenital heart disease were shared risk factors for mortality (HR, 1.07; P = .05; HR, 2.9; P = .003) and delisting because of clinical deterioration (HR, 1.17; P = .01; HR, 2.8; P = .02). Younger age at listing and fetal listing were associated with delisting for clinical improvement or surgical intervention (HR, 1.13; P = .01; HR, 2.9; P = .02).

CONCLUSIONS

Overall survival to transplant depends on risk factors including age at listing, cardiac diagnosis, and mechanical circulatory support. Knowledge of risk factors for death and delisting for clinical deterioration or improvement can assist patient selection and timing of transplant listing.

Options for the failing ventricle in pediatric heart disease

The management of the pediatric patient with the failing ventricle poses its own therapeutic challenges, not least because patient size limits options available. Once medical management has hit its ceiling, attention is turned to surgical options for mechanical support. The approach to these options has to bear in mind that there may be many potential causes for pump failure, and that these occur often in the context of pulmonary hypertension and poor gas exchange. Although extracorporeal life support has been the mainstay of treatment for acute heart failure, in the last decade, attention has been focusing on longer-term options to bridge to recovery or eventual transplant. Added to this are more novel applications of ventricular assist devices, notable in the management of the failing Fontan circulation where there are no perfect solutions. There is growing interest in the use of such devices to power this delicate circulation and extend the functional capacity of patients without resorting to transplantation. In this review article, we explore the role each of these surgical modalities has to play in the management of the child with acute and chronic heart failure, and explore the recent developments in the rapidly growing field of pediatric ventricular assist.

The Berlin Heart EXCOR Pediatric ventricular assist device: history, North American experience, and future directions

Options for long-term mechanical circulatory support to sustain pediatric heart failure patients requiring cardiac transplantation while they wait for donor hearts have been unsatisfactory. The conventional approach has been to use extracorporeal membrane oxygenation (ECMO), but its lack of feasibility for long-term use and the major complications associated with the technology have limited its use, especially in light of lengthy waiting lists for donor hearts. With the advent of the Berlin Heart EXCOR® Pediatric ventricular assist device (VAD), pediatric heart failure specialists have gained an important tool for helping this patient population survive until a donor heart can be identified. The EXCOR Pediatric VAD is designed to support pediatric patients of all age groups, from newborns to teenagers, and can be used successfully for many months. This paper describes the early experience with the EXCOR Pediatric VAD and the challenging journey undertaken to gain U.S. FDA approval, including successful completion of the first worldwide prospective clinical study of VADs in a pediatric population.

Pre-clinical evaluation of the infant Jarvik 2000 heart in a neonate piglet model

BACKGROUND

The infant Jarvik 2000 heart is a very small, hermetically sealed, intracorporeal, axial-flow ventricular assist device (VAD) designed for circulatory support in neonates and infants. The anatomic fit, short-term biocompatibility and hemodynamic performance of the device were evaluated in a neonate piglet model.

METHODS

The infant Jarvik 2000 heart with two different blade profiles (low- or high-flow blade design) was tested in 6 piglets (8.8 ± 0.9 kg). Using a median sternotomy, the pump was placed in the left ventricle through the apex without cardiopulmonary bypass. An outflow graft was anastomosed to the ascending aorta. Hemodynamics and biocompatibility were studied for 6 hours.

RESULTS

All 6 pumps were implanted without complication. Optimal anatomic positioning was found with the pump body inserted 2.4 cm into the left ventricle. Hemodynamics demonstrated stability throughout the 6-hour duration. The pump flow increased from 0.27 to 0.95 liter/min at increasing speeds from 18 to 31 krpm for the low-flow blade design, whereas the pump flow increased from 0.54 liter/min to 1.12 liters/min at increasing speeds from 16 krpm to 31 krpm for the high-flow blade design. At higher speeds, >80% of flow could be supplied by the device. Blood chemistry and final pathology demonstrated no acute organ injury or thrombosis for either blade design.

CONCLUSIONS

The infant Jarvik 2000 heart is anatomically and biologically compatible with an short-term neonate piglet model. This in vivo study demonstrates the future feasibility of this device for clinical use.

Pediatric extracorporeal life support in specialized situations

OBJECTIVES

The purpose of this review was to provide a systematic review of the literature regarding the use of extracorporeal life support (ECLS) in various specialized conditions, as part of the Pediatric Cardiac Intensive Care Society/Extracorporeal Life Support Organization Joint Statement on Mechanical Circulatory Support.

DATA SOURCES

MEDLINE and PubMed.

STUDY SELECTION

Searches for published abstracts and articles were conducted using the following MeSH terms: extracorporeal life support, extracorporeal membrane oxygenation, or mechanical support, and pediatric or children.

DATA EXTRACTION

Abstracts of all articles including case reports were reviewed; the full article was reviewed if the abstract indicated that it focused on extracorporeal life support for conditions other than primary respiratory disease or persistent pulmonary hypertension of the newborn and described outcomes such as survival to hospital discharge. Studies with potential overlapping patients were highlighted in the review process and summary results.

DATA SYNTHESIS

Classification of recommendations and level of evidence are expressed in the American College of Cardiology Foundation/American Heart Association format.

CONCLUSIONS

The majority of specialized situations where extracorporeal life support is used fall into the category of class II-III evidence. Class I indications for extracorporeal life support in the pediatric population include myocarditis and in the context of acute interventions in the cardiac catheterization laboratory.

Berlin Heart EXCOR pediatric ventricular assist device for bridge to heart transplantation in US children

BACKGROUND

Recent data suggest that the Berlin Heart EXCOR Pediatric ventricular assist device is superior to extracorporeal membrane oxygenation for bridge to heart transplantation. Published data are limited to 1 in 4 children who received the device as part of the US clinical trial. We analyzed outcomes for all US children who received the EXCOR to characterize device outcomes in an unselected cohort and to identify risk factors for mortality to facilitate patient selection.

METHODS AND RESULTS

This multicenter, prospective cohort study involved all children implanted with the Berlin Heart EXCOR Pediatric ventricular assist device at 47 centers from May 2007 through December 2010. Multiphase nonproportional hazards modeling was used to identify risk factors for early (<2 months) and late mortality. Of 204 children supported with the EXCOR, the median duration of support was 40 days (range, 1-435 days). Survival at 12 months was 75%, including 64% who reached transplantation, 6% who recovered, and 5% who were alive on the device. Multivariable analysis identified lower weight, biventricular assist device support, and elevated bilirubin as risk factors for early mortality and bilirubin extremes and renal dysfunction as risk factors for late mortality. Neurological dysfunction occurred in 29% and was the leading cause of death.

CONCLUSIONS

Use of the Berlin Heart EXCOR has risen dramatically over the past decade. The EXCOR has emerged as a new treatment standard in the United States for pediatric bridge to transplantation. Three-quarters of children survived to transplantation or recovery; an important fraction experienced neurological dysfunction. Smaller patient size, renal dysfunction, hepatic dysfunction, and biventricular assist device use were associated with mortality, whereas extracorporeal membrane oxygenation before implantation and congenital heart disease were not.

Pediatric outcomes after extracorporeal membrane oxygenation for cardiac disease and for cardiac arrest: a review

We reviewed reported survival and neurological outcomes, and predictors of these outcomes for pediatric cardiac extracorporeal membrane oxygenation (ECMO) and extracorporeal cardiopulmonary resuscitation (ECPR). We searched PubMed from 2000 to April 2011. Cumulative survival after cardiac ECMO in children was 788/1755 (45%); renal dysfunction, dialysis, neurologic complication, lactate, and ECMO duration consistently predicted this outcome, whereas single ventricle and ECPR did not. Neurological outcomes after cardiac ECMO were based on poorly described telephone questions in two studies for 47 patients with 51% significantly impaired and detailed follow-up testing for 42 patients in three studies with mental delay in 38% and mental score >85 (average or above) in 33%. Cumulative survival after ECPR in children was 371/762 (49%); noncardiac disease, renal dysfunction, neurologic complication, and pH on extracorporeal life support consistently predicted this outcome, whereas duration of CPR did not. Neurological outcomes after ECPR were based predominantly on the pediatric cerebral performance category (PCPC) score by chart review, with 161/181 (79%) having PCPC <2. No study reported detailed follow-up testing for survivors of ECPR. Survival outcomes of most cardiac subgroups were similar, except for concerning mortality in cavopulmonary connection patients. Priority areas for study include identification of potentially modifiable predictors of long-term outcomes.

Current Outcomes in US Children With Cardiomyopathy Listed for Heart Transplantation

Background—

Previous studies have reported worse outcomes in children with nondilated cardiomyopathy (CMP) listed for heart transplant compared with children with dilated CMP. We sought to compare wait-list and posttransplant outcomes in these groups in the current era.

Methods and Results—

We analyzed all children <18 years of age with a diagnosis of CMP listed for heart transplant in the United States between July 2004 and December 2010. Multivariable risk factors for death on the wait-list (or becoming too sick to transplant) and posttransplant graft loss (median follow-up 2 years) were assessed using Cox models. Of the 1436 children analyzed, 1197 (83%) had dilated CMP and 239 (17%) had nondilated CMP (167 restrictive CMP, 72 hypertrophic CMP). In adjusted analysis, children with nondilated CMP were at higher risk of wait-list mortality only if they were on a ventilator support at listing (hazard ratio, 2.3; CI, 1.2–4.5). The risk was similar among children not on a ventilator support (hazard ratio, 0.6; CI, 0.3–1.1). Posttransplant 30-day and 1-year survival was 98% and 94%, respectively, in children with dilated CMP versus 95% and 89%, respectively, in children with nondilated CMP ( P =0.17, log-rank test). In adjusted analysis, the risk of posttransplant graft loss was higher in nondilated CMP (hazard ratio, 1.8; CI, 1.2–2.7) versus dilated CMP.

Conclusions—

The increased risk of wait-list mortality in children with nondilated CMP is limited to those on ventilator support at listing. Although the risk of graft loss is modestly higher in children with nondilated forms of CMP, their short-term transplant outcomes are good.

Prospective trial of a pediatric ventricular assist device

BACKGROUND

Options for mechanical circulatory support as a bridge to heart transplantation in children with severe heart failure are limited.

METHODS

We conducted a prospective, single-group trial of a ventricular assist device designed specifically for children as a bridge to heart transplantation. Patients 16 years of age or younger were divided into two cohorts according to body-surface area (cohort 1, <0.7 m(2); cohort 2, 0.7 to <1.5 m(2)), with 24 patients in each group. Survival in the two cohorts receiving mechanical support (with data censored at the time of transplantation or weaning from the device owing to recovery) was compared with survival in two propensity-score-matched historical control groups (one for each cohort) undergoing extracorporeal membrane oxygenation (ECMO).

RESULTS

For participants in cohort 1, the median survival time had not been reached at 174 days, whereas in the matched ECMO group, the median survival was 13 days (P<0.001 by the log-rank test). For participants in cohort 2 and the matched ECMO group, the median survival was 144 days and 10 days, respectively (P<0.001 by the log-rank test). Serious adverse events in cohort 1 and cohort 2 included major bleeding (in 42% and 50% of patients, respectively), infection (in 63% and 50%), and stroke (in 29% and 29%).

CONCLUSIONS

Our trial showed that survival rates were significantly higher with the ventricular assist device than with ECMO. Serious adverse events, including infection, stroke, and bleeding, occurred in a majority of study participants. (Funded by Berlin Heart and the Food and Drug Administration Office of Orphan Product Development; ClinicalTrials.gov number, NCT00583661.).

Pushing the boundaries: the current status of ABO-incompatible cardiac transplantation

Since the introduction of intentional ABO-incompatible (ABOi) cardiac transplantation in infants in the late 1990's, the number of patients listed for and undergoing ABOi transplants has increased. This practice has been shown to lead to a reduction in waiting list mortality and increased utilisation of donor organs with equivalent outcomes to ABO-compatible transplants. Differences in the infant immune system provide a window of opportunity for ABOi transplantation. However it is increasingly clear that older patients and those with significant amounts of blood group antibody specific isohaemagglutinins may also benefit. Newer research is now focussing on longer term outcomes of ABOi transplants - in particular the development of graft accommodation or tolerance. This review assesses the current status of ABO-incompatible cardiac transplantation both in infants and in sensitized and older patients.

Trends in wait-list mortality in children listed for heart transplantation in the United States: era effect across racial/ethnic groups

We sought to evaluate trends in overall and race-specific pediatric heart transplant (HT) wait-list mortality in the United States (US) during the last 20 years. We identified all children <18 years old listed for primary HT in the US during 1989-2009 (N = 8096, 62% White, 19% Black, 13% Hispanic and 6% Other) using the Organ Procurement and Transplant Network database. Wait-list mortality was assessed in four successive eras (1989-1994, 1995-1999, 2000-2004 and 2005-2009). Overall wait-list mortality declined in successive eras (26%, 23%, 18% and 13%, respectively). The decline across eras remained significant in adjusted analysis (hazard ratio [HR] 0.70 in successive eras, 95% confidence interval [CI], 0.67-0.74) and was 67% lower for children listed during 2005-2009 versus those listed during 1989-1994 (HR 0.33; CI, 0.28-0.39). In models stratified by race, wait-list mortality decreased in all racial groups in successive eras. In models stratified by era, minority children were not at higher risk of wait-list mortality in the most recent era. We conclude that the risk of wait-list mortality among US children listed for HT has decreased by two-thirds during the last 20 years. Racial gaps in wait-list mortality present variably in the past are not present in the current era.

Perioperative mechanical circulatory support in children with critical heart disease

OPINION STATEMENT

The treatment of cardiovascular failure in the perioperative period with the use of mechanical circulatory support is a well-recognized, well-developed, and commonly utilized treatment modality. Regardless of the exact circumstances of initiation, the use of a support device is a "bridge." Where there has been an acute myocardial insult, short-term assist devices can serve as a "bridge to immediate survival," a "bridge to recovery," or even a "bridge to the next decision." Mechanical circulatory support can serve as a treatment of cardiovascular decompensation caused by myocarditis, acute myocardial insult, low cardiac output following surgery, and congenital heart disease. The utilization of such support carries significant risks such as bleeding, infection, and thrombosis. However, these can be minimized in order to allow for the safe and effective deployment of this therapeutic strategy. One specific therapeutic domain in which these devices provide immediate impact is during cardiac arrest. Although outcomes of cardiac arrest remain poor, use of a mechanical device as an intervention has allowed salvage of otherwise certain mortality. However, it is important to note that the utility of support was most pronounced in patients that were not on either extreme of the survival prediction curve. This can be best summarized by the concept of "not too early, not too late." Therefore, it is the responsibility of the entire care team to find the appropriate patient population in which to "pull the trigger" on mechanical support as a therapy. This decision point is supported by a monitoring strategy that can be utilized to predict deterioration and intervene adequately. Most importantly, an effective monitoring strategy allows the practitioner to judge the effectiveness of treatment and support strategies and make adjustments in a timely manner, potentially with mechanical support in the perioperative period.

Impact of donor cardiopulmonary resuscitation on pediatric heart transplant outcome

Mortality is the highest of any solid organ in pediatric patients awaiting heart transplantation. Strategies to increase the donor pool are needed if survival to transplant is to improve. There can be reluctance to accept pediatric hearts for transplantation if the donor has received cardiopulmonary resuscitation (CPR). This study asked if donor CPR impacts the survival of pediatric heart transplant recipients. Analysis of the UNOS database was performed for all cardiac transplants performed in patients aged 0-18 yr, with donors classified as to whether they received CPR (CPR+) or not (CPR-). We compared overall survival and survival at 30 days, one yr, and five yr between groups. Within the CPR+ group, the impact of duration of CPR on survival was compared. The need for inotropic support and ejection fraction was compared between donor groups as a measure of organ function. Overall survival and survival at 30 days, one yr, and five yr did not differ in the CPR+ compared to the CPR- group. Within the CPR+ group, duration of CPR was unrelated to post-transplant survival. The need for inotropic support at procurement was similar, and ejection fraction did not differ between the CPR+ and CPR- groups. Donor CPR does not have a negative impact on pediatric heart transplant survival.

Racial and ethnic disparities in post-operative mortality following congenital heart surgery

OBJECTIVES

This study assessed racial/ethnic disparities in post-operative mortality after surgery for congenital heart disease (CHD) and explored whether disparities persist after adjusting for access to care.

STUDY DESIGN

We used the Pediatric Health Information System database to perform a retrospective cohort study of 44,017 patients with 49,833 CHD surgery encounters in 2004-2008 at 41 children's hospitals. We used χ(2) analysis to compare unadjusted mortality rates by race/ethnicity (non-Hispanic white, non-Hispanic black, Hispanic) and constructed Poisson regression models to determine adjusted mortality risk ratios (RRs) and 95% CIs.

RESULTS

In-hospital post-operative mortality rate was 3.4%; non-Hispanic whites had the lowest mortality rate (2.8%), followed by non-Hispanic blacks (3.6%) and Hispanics (3.9%) (P < .0001). After adjusting for age, sex, genetic syndrome, and surgery risk category, the RR of death was 1.32 for non-Hispanic blacks (CI, 1.14-1.52) and 1.21 for Hispanics (CI, 1.07-1.37), both compared with non-Hispanic whites. After adjusting for access to care (insurance type and hospital of surgery), these estimates did not appreciably change (non-Hispanic blacks: RR, 1.27; CI, 1.09-1.47; Hispanics: RR, 1.22; CI, 1.05-1.41).

CONCLUSIONS

There are notable racial/ethnic disparities in post-operative mortality after CHD surgery that do not appear to be explained by differences in access to care.

Extracorporeal Membrane Oxygenation for Bridge to Heart Transplantation Among Children in the United States

Background—

Extracorporeal membrane oxygenation (ECMO) has served for >2 decades as the standard of care for US children requiring mechanical support as a bridge to heart transplantation. Objective data on the safety and efficacy of ECMO for this indication are limited. We describe the outcomes of ECMO as a bridge to heart transplantation to serve as performance benchmarks for emerging miniaturized assist devices intended to replace ECMO.

Methods and Results—

Data from the Extracorporeal Life Support Organization Registry and the Organ Procurement Transplant Network database were merged to identify children supported with ECMO and listed for heart transplantation from 1994 to 2009. Independent predictors of wait-list and posttransplantation in-hospital mortality were identified. Objective performance goals for ECMO were developed. Of 773 children, the median age was 6 months (interquartile range, 1 to 44 months); 28% had cardiomyopathy; and in 38%, a bridge to transplantation was intended at ECMO initiation. Overall, 45% of subjects reached transplantation, although one third of those transplanted died before discharge; overall survival to hospital discharge was 47%. Wait-list mortality was independently associated with congenital heart disease, cardiopulmonary resuscitation before ECMO, and renal dysfunction. Posttransplantation mortality was associated with congenital heart disease, renal dysfunction, ECMO duration of >14 days, and initial ECMO indication as a bridge to recovery. In the objective performance goal cohort (n=485), patients with cardiomyopathy had the highest survival to hospital discharge (63%), followed by patients with myocarditis (59%), 2-ventricle congenital heart disease (44%) and 1-ventricle congenital heart disease (33%).

Conclusion—

Although ECMO is effective for short-term circulatory support, it is not reliable for the long-term circulatory support necessary for children awaiting heart transplantation. Fewer than half of patients bridged with ECMO survive to hospital discharge. More effective modalities for chronic circulatory support in children are urgently needed.

Heart transplantation for congenital heart disease in the first year of life

Successful infant heart transplantation has now been performed for over 25 years. Assessment of long term outcomes is now possible. We report clinical outcomes for322 patients who received their heart transplant during infancy. Actuarial graft survival for newborn recipients is 59% at 25 years. Survival has improved in the most recent era. Cardiac allograft vasculopathy is the most important late cause of death with an actuarial incidence at 25 years of 35%. Post-transplant lymphoma is estimated to occur in 20% of infant recipients by25 years. Chronic kidney disease grade 3 or worse is present in 31% of survivors. The epidemiology of infant heart transplantation has changed through the years as the results for staged repair improved and donor resources remained stagnant. Most centers now employ staged repair for hypoplastic left heart syndrome and similar extreme forms of congenital heart disease. Techniques for staged repair, including the hybrid procedure, are described. The lack of donors is described with particular note regarding decreased donors due to newer programs for appropriate infant sleep positioning and infant car seats. ABO incompatible donors are a newer resource for maximizing donor resources, as is donation after circulatory determination of death and techniques to properly utilize more donors by expanding the criteria for what is an acceptable donor. An immunological advantage for the youngest recipients has long been postulated, and evaluation of this phenomenon may provide clues to the development of accommodation and/or tolerance.

Factors associated with in-hospital mortality in infants undergoing heart transplantation in the United States

OBJECTIVE

Infants undergoing heart transplantation have the highest early posttransplant mortality of any age group. We sought to determine the pretransplantation factors associated with in-hospital mortality in transplanted infants in the current era.

METHODS

All infants under 12 months of age who underwent primary heart transplantation during a recent 10-year period (1999-2009) in the United States were identified using the Organ Procurement and Transplant Network database. Multivariable logistic regression was used to identify independent pretransplantation factors associated with in-hospital mortality.

RESULTS

Of 730 infants in the study (median age 3.8 months), 462 (63%) had congenital heart disease, 282 (39%) were supported by a ventilator, 94 (13%) with extracorporeal membrane oxygenation, and 22 (3%) with a ventricular assist device at the time of transplantation. Overall, 82 (11.2%) infants died before their initial hospital discharge. In adjusted analysis, in-hospital mortality was associated with repaired congenital heart disease (odds ratio [OR], 3.6; 95% confidence interval [CI], 1.8, 7.2), unrepaired congenital heart disease not on prostaglandin E (OR, 2.8; CI, 1.3, 6.1), extracorporeal membrane oxygenator support (OR, 6.1; CI, 2.8, 13.4), ventilator support (OR, 4.4; CI, 2.3, 8.3), creatinine clearance less than 40 mL·min(-1)·1.73 m(-2) (OR, 3.1; CI, 1.7, 5.3), and dialysis (OR, 6.2; CI, 2.1, 18.3) at transplantation.

CONCLUSIONS

One in 9 infants undergoing heart transplantation dies before hospital discharge. Pretranplantation factors associated with early mortality include congenital heart disease, extracorporeal membrane oxygenator support, mechanical ventilation, and renal failure. Risk stratification for early posttransplant mortality among infants listed for heart transplantation may improve decision-making for transplant eligibility, organ allocation, and posttransplant interventions to reduce mortality.

Impact of ABO-incompatible listing on wait-list outcomes among infants listed for heart transplantation in the United States: a propensity analysis

BACKGROUND

The purported advantage of ABO-incompatible (ABO-I) listing is to reduce wait times and wait-list mortality among infants awaiting heart transplantation. We sought to describe recent trends in ABO-I listing for US infants and to determine the impact of ABO-I listing on wait times and wait-list mortality.

METHODS AND RESULTS

In this multicenter retrospective cohort study using Organ Procurement and Transplant Network data, infants<12 months of age listed for heart transplantation between 1999 and 2008 (n=1331) were analyzed. Infants listed for an ABO-I transplant were compared with a propensity score-matched cohort listed for an ABO-compatible transplant through the use of a Cox shared-frailty model. The primary end point was time to heart transplantation. The percentage of eligible infants listed for an ABO-I heart increased from 0% before 2002 to 53% in 2007 (P<0.001 for trend). Compared with infants listed exclusively for an ABO-compatible heart, infants with a primary ABO-I listing strategy (n=235) were more likely to be listed 1A, to have congenital heart disease and renal failure, and to require extracorporeal membrane oxygenation. For the propensity score-matched groups (n=197 matched pairs), there was no difference in wait-list mortality; however, infants with blood type O assigned an ABO-I listing strategy were more likely to undergo heart transplantation by 30 days (31% versus 16%; P=0.007) with a less pronounced effect for infants with other blood types.

CONCLUSIONS

The proportion of US infants listed for an ABO-I heart transplantation has risen dramatically in recent years but still appears to be preferentially used for sicker infant candidates. The ABO-I listing strategy is associated with a higher likelihood of transplantation within 30 days for infants with blood group O and may benefit a broader range of transplantation candidates.

Heart transplantation in children

In the last 40 years, orthotopic heart transplantation has been established as a realistic treatment strategy for infants and children with severe forms of congenital heart disease and cardiomyopathy. The evaluation, management, and outcomes of these patients have continued to improve. These achievements have advanced pediatric cardiac transplantation and allowed more attention to be focused on improving quality of life after transplantation and reducing the long-term complications.