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.

Improved survival in pediatric heart transplant recipients: have white, black and Hispanic children benefited equally?

We assessed whether the improvement in posttransplant survival in pediatric heart transplant (HT) recipients during the last two decades has benefited the major racial groups in the United States equally. We analyzed all children <18 years of age who underwent their first HT in the US during 1987-2008. We compared trends in graft loss (death or retransplant) in white, black and Hispanic children in five successive cohorts (1987-1992, 1993-1996, 1997-2000, 2001-2004, 2005-2008). The primary endpoint was early graft loss within 6 months posttransplant. Longer-term survival was assessed in recipients who survived the first 6 months. The improvement in early posttransplant survival was similar (hazard ratio [HR] for successive eras 0.80, 95% confidence interval [CI] 0.7, 0.9, p = 0.24 for black-era interaction, p = 0.22 for Hispanic-era interaction) in adjusted analysis. Longer-term survival was worse in black children (HR 2.2, CI 1.9, 2.5) and did not improve in any group with time (HR 1.0 for successive eras, CI 0.9, 1.1, p = 0.57; p = 0.19 for black-era interaction, p = 0.21 for Hispanic-era interaction). Thus, the improvement in early post-HT survival during the last two decades has benefited white, black and Hispanic children equally. Disparities in longer-term survival have not narrowed with time; the survival remains worse in black recipients.

Racial and ethnic differences in mortality in children awaiting heart transplant in the United States

Racial differences in outcomes are well known in children after heart transplant (HT) but not in children awaiting HT. We assessed racial and ethnic differences in wait-list mortality in children <18 years old listed for primary HT in the United States during 1999-2006 using multivariable Cox models. Of 3299 listed children, 58% were listed as white, 20% as black, 16% as Hispanic, 3% as Asian and 3% were defined as 'Other'. Mortality on the wait-list was 14%, 19%, 21%, 17% and 27% for white, black, Hispanic, Asian and Other children, respectively. Black (hazard ratio [HR] 1.6, 95% confidence interval [CI] 1.3, 1.9), Hispanic (HR 1.5, CI 1.2, 1.9), Asian (HR, 2.0, CI 1.3, 3.3) and Other children (HR 2.3, CI 1.5, 3.4) were all at higher risk of wait-list death compared to white children after controlling for age, listing status, cardiac diagnosis, hemodyamic support, renal function and blood group. After adjusting additionally for medical insurance and area household income, the risk remained higher for all minorities. We conclude that minority children listed for HT have significantly higher wait-list mortality compared to white children. Socioeconomic variables appear to explain a small fraction of this increased risk.

Hypoplastic Left Heart Syndrome With Intact or Highly Restrictive Atrial Septum: Surgical Experience From a Single Center

BACKGROUND

The presence of an intact or highly restrictive atrial septum (I/HRAS) has long been recognized as a predictor of poor outcome among patients with hypoplastic left heart syndrome (HLHS), although the rarity of this condition has precluded conclusive study. The purpose of this review is to summarize recent surgical outcomes for these patients at our center and to identify predictors.

METHODS

We retrospectively identified all neonates with a diagnosis of HLHS and I/HRAS who underwent stage I palliation at Children's Hospital Boston between January 2001 and December 2006. Chart review enabled analysis of patient and procedural variables.

RESULTS

All 32 patients underwent left atrial decompression in utero or postnatally before surgery. Fourteen patients (44%) underwent fetal intervention, either atrial septoplasty (n = 9) or aortic valvuloplasty (n = 5). Twenty-nine of the 32 patients had postnatal left atrial hypertension and underwent transcatheter atrial septoplasty as neonates before surgery; 3 did not require postnatal atrial septoplasty after successful fetal atrial septoplasty. After stage I, hospital survival was 69% (22 of 32). Need for shunt revision (p = 0.02) and for extracorporeal membrane oxygenation use (p < 0.001) were associated with hospital mortality. Survival at 6 months was 69% for patients who had fetal intervention, and 38% for those who were treated only postnatally (p = 0.2).

CONCLUSIONS

Surgical outcome for patients with HLHS and I/HRAS continues to improve. Prenatal decompression of the left atrium may be associated with greater hospital survival. Proposed effects of fetal intervention on lung pathology and longer-term survival are subjects for future study in this unique group of patients.

Ventricular size and function assessed by cardiac MRI predict major adverse clinical outcomes late after tetralogy of Fallot repair

BACKGROUND

Factors associated with impaired clinical status in a cross-sectional study of patients with repaired tetralogy of Fallot (TOF) have been reported previously.

OBJECTIVES

To determine independent predictors of major adverse clinical outcomes late after TOF repair in the same cohort during follow-up evaluated by cardiac magnetic resonance (CMR).

METHODS

Clinical status at latest follow-up was ascertained in 88 patients (median time from TOF repair to baseline evaluation 20.7 years; median follow-up from baseline evaluation to most recent follow-up 4.2 years). Major adverse outcomes included (a) death; (b) sustained ventricular tachycardia; and (c) increase in NYHA class to grade III or IV.

RESULTS

22 major adverse outcomes occurred in 18 patients (20.5%): death in 4, sustained ventricular tachycardia in 8, and increase in NYHA class in 10. Multivariate analysis identified right ventricular (RV) end-diastolic volume Z >or=7 (odds ratio (OR) = 4.55, 95% confidence interval (CI) 1.10 to 18.8, p = 0.037) and left ventricular (LV) ejection fraction <55% (OR = 8.05, 95% CI 2.14 to 30.2, p = 0.002) as independent predictors of outcome with an area under the receiver operator characteristic curve of 0.850. LV ejection fraction could be replaced by RV ejection fraction <45% in the multivariate model. QRS duration >or=180 ms also predicted major adverse events but correlated with RV size.

CONCLUSIONS

In this cohort, severe RV dilatation and either LV or RV dysfunction assessed by CMR predicted major adverse clinical events. This information may guide risk stratification and therapeutic interventions.

Racial and ethnic disparities in mortality following congenital heart surgery

Our objective was to assess risk-adjusted racial and ethnic disparities in mortality following congenital heart surgery. We studied 8483 congenital heart surgical cases from the Kids' Inpatient Database 2000. Black sub-analysis was performed using predetermined regional categories. For our Hispanic sub-analyses, we categorized Hispanics into state groups according to a state's predominant Hispanic group: West (Mexican-American), Southeast (Cuban-American), Northeast (Puerto Rican), and Mixed/Heterogeneous. Risk adjustment was performed using the Risk Adjustment for Congenital Heart Surgery method. Multivariate analyses assessed the effect of race/ethnicity and Hispanic state group on mortality and explored the effects of gender, income, insurance type, and region. Black children had a higher risk for death than Whites odds ratio (OR), [1.65; p = 0.003]. Hispanics and the Cuban-American state group showed a trend toward a higher death risk (Hispanic: OR, 1.24; p = 0.16; Southeast Cuban-American: OR 1.55; p = 0.08). Disparities were not influenced by insurance. Among Blacks, disparities were greatest in the Northeast region (OR, 2.25; p = 0.007). After adjusting for gender, income, and region, Blacks (OR, 1.76; p = 0.002) and Hispanics (OR, 1.34; p = 0.05) had a higher death risk. Racial and ethnic disparities in risk-adjusted mortality following congenital heart disease exist for Blacks and Hispanics. These disparities are not due to insurance but are partially explained by gender and region.

Prospective single-arm protocol of carvedilol in children with ventricular dysfunction

The objective of this study was to evaluate the safety and efficacy of carvedilol in pediatric patients with stable moderate heart failure. We performed a single-arm prospective drug trial at three academic medical centers and the results were compared to historical controls. Patients were 3 months to 17 years old with an ejection fraction <40% in the systemic ventricle for at least 3 months on maximal medical therapy including ACE inhibitors. Treated patients were started on 0.1 mg/kg/day and uptitrated to 0.8 mg/kg/day or the maximal tolerated dose. Echocardiographic parameters of function were prospectively measured at entry and at 6 months. Two composite endpoints were recorded: severe decline in status and significant clinical change. Adverse events were reviewed by a safety committee. Data were also collected from untreated controls with dilated cardiomyopathy meeting entry criteria, assessed over a similar time frame. Twenty patients [12 dilated cardiomyopathy (DCM) and 8 congenital] with a median age of 8.4 years (range, 8 months to 17.8 years) were treated with carvedilol. Three patients discontinued the drug during the study. At entry, there was no statistical difference in age, weight, or ejection fraction between the treated group and controls. The ejection fraction of the treated DCM group improved significantly from entry to 6 months (median, 31 to 40%, p = 0.04), with no significant change in ejection fraction in the control group [median, 29 to 27%, p = not significant (NS)]. The median increase in ejection fraction was larger for the treated DCM group than for the untreated DCM controls (7 vs 0%, p = 0.05). By Kaplan-Meier analysis, time to death or transplant tended to be longer in treated patients (p = 0.07). The difference in the proportion of patients with severe decline in status or significant clinical change in the treated group was not significant compared to the controls (5 vs 12%, p = NS). We conclude that in this prospective protocol of pediatric patients, the use of adjunct carvedilol in the DCM group improved ejection fraction compared to untreated controls and trended toward delaying time to transplant or death.

Health-related quality of life in children attending a cardiology clinic

Our purpose was to evaluate the impact of suspicion or confirmation of heart disease on the physical and psychosocial health of children. We utilized the Child Health Questionnaire (CHQ PF-50). Children ages 5 to 18 years attending a general cardiology clinic were eligible. Those with primary noncardiac diagnoses unrelated to heart disease were excluded. Children with similar conditions were grouped together for analysis. Group and subgroup means were compared to a U.S. population normative sample using the two-sample t test. The CHQ was administered to 321 patients (median age, 10.6 years). Overall, parents reported mean Physical and Psychosocial Summary Scores comparable to those for the normative sample (mean, 51.5 vs 53.0, p = 0.04; mean, 52.3 vs 51.2, p = 0.10). There was a trend toward worse physical health in most subgroups, especially those with cardiomyopathy (CM) (46.5; p = 0.01), and a comparable trend toward better psychosocial health except in those requiring major interventions. In subscale analyses, most subgroups reported worse Physical Functioning than the normative sample, especially CM (85.1 vs 96.1; p = 0.02). Parents of children with CM (53.2 vs 73.0; p = 0.002) and the intervention subgroups (except minor) reported worse General Health Perceptions. Parents experienced increased Parental Impact-Emotional, especially parents of children undergoing evaluations for chest pain (62.5 vs 80.3; p = 0.007). Most parents reported comparable or better health for the Family Cohesion and Bodily Pain subscales. Generally, parents of children attending a cardiology clinic report physical and psychosocial health comparable to that for the general U.S. population. However, diagnosis or confirmation of heart disease resulted in worse physical functioning and health perceptions and a significant negative emotional impact on parents.

Risk of death for Medicaid recipients undergoing congenital heart surgery

The objective of this study was to explore the effect of insurance type on mortality for congenital heart surgery. We performed a population-based retrospective cohort study using hospital discharge abstract data from five states in 1992 and 1996. The outcome measure was risk-adjusted in-hospital mortality. Cases of pediatric congenital heart surgery were identified and placed into six risk categories using the Risk Adjustment in Congenital Heart Surgery method. Multivariate analyses were used to determine the effect of insurance type on risk-adjusted mortality; regional effects were explored. Using standardized mortality ratios, institutions were grouped by outcome; within and between group differences were examined. Of 11,636 cases, 9656 (83%) were placed in a risk group for analysis. In 1996, children with Medicaid had a higher risk of death than those with commercial or managed care in both unadjusted (p = 0.002) and adjusted (p < 0.001) analyses. Overall mortality rates decreased between 1992 and 1996 (p = 0.001). However, improvement was not consistent among insurance groups. Differences were present within and between low, average, and high-mortality hospitals, suggesting that the adverse effect of Medicaid may be due to both differential referral and other differences in care among patients treated at similar institutions. Children with Medicaid insurance have a higher risk of dying after congenital heart surgery than those with commercial and some managed care insurance. Barriers to access go beyond differences in referral patterns.

Regional racial and ethnic differences in mortality for congenital heart surgery in children may reflect unequal access to care

The objective of this study was to explore racial differences in mortality for congenital heart surgery. We performed a population-based retrospective cohort study using hospital discharge abstract data from four states in 1996. The outcome measure was risk-adjusted in-hospital mortality. Cases of pediatric congenital heart surgery were classified into six risk categories using the Risk Adjustment in Congenital Heart Surgery method. Differences in risk-adjusted in-hospital mortality among racial groups were explored. Analyses stratified by state were used to identify regional differences. Of 5791 cases, 4822 (83%) were assigned to a risk group for analysis. Surgical mortality differed for whites compared to non-whites (3.7 vs 5.1%, p = 0.02). Among non-white groups, unadjusted mortality rates varied: Asian, 5.3%; black, 4.1%; Hispanic 4.9%; other, 7.3%; and missing, 7.6% (p = 0.008). Adjusted mortality also differed by race but was inconsistent across regions, making explanatory factors based solely on biology implausible. For example, compared to whites, blacks had a higher risk of dying in Massachusetts [odds ratio (OR) = 6.39, p = 0.08] but lower in Pennsylvania (OR = 0.41, p = 0.009). Adding insurance type to models did not eliminate racial differences. In risk-adjusted analyses, non-white groups had a higher risk of dying after congenital heart surgery than whites. Inconsistent effects among regions suggest that differential mortality is due to unequal access to care rather than biology.

Healing response to the Clamshell device for closure of intracardiac defects in humans

The healing response to intracardiac devices in humans is largely unknown. During regulatory trials using the Clamshell device in over 800 patients, attempts were made to perform histopathological evaluation of all explanted devices. We reviewed all those with complete histopathological examination (n = 12) from Fontan baffles (n = 4), ventricular septal defects (n = 2), and atrial septal defects (ASD; n = 6), explanted at 2.7 months to 3.6 years (median, 1.6 years), at autopsy (n = 1) or surgery (n = 11), performed for residual defects (n = 5), atrial masses (n = 3), or Fontan revision (n = 3). All but one were nearly (n = 3) or completely (n = 8) covered by pseudointima, composed of fibroelastic tissue, predominantly collagen, with focal foreign body reaction in contact with fabric, without acute inflammation or infection. Atrial masses of granulation tissue were present in three cases (ASD), opposite to protruding fractured arms. No associations were identified between coverage and closure status, position, arm fractures, or implant period. In conclusion, the healing response to transcatheter Clamshell implantation in humans is characterized by a relatively rapid development of a nonthrombotic pseudointima composed of fibroelastic tissue with minimal foreign body reaction. Cathet Cardiovasc Intervent 2001;54:101-111.

Predictors of outcome of biventricular repair in infants with multiple left heart obstructive lesions

BACKGROUND

Decisions regarding surgical strategy in patients with multiple left heart obstructive or hypoplastic lesions often must be made in the newborn period and are seldom reversible. Predictors of outcome of biventricular repair have not been well defined in this heterogeneous group of patients, and risk factors described for critical aortic valve stenosis have been shown to be inapplicable to patients with other left heart obstructive lesions. The goal of this study was to identify echocardiographic predictors of outcome of biventricular repair for infants with multiple left heart obstructive lesions.

METHODS AND RESULTS

Patients with >/=2 areas of left heart obstruction or hypoplasia, diagnosed at </=3 months of age, who had not previously undergone surgical or catheter intervention and maintained biventricular physiology were included (n=72). Failure of biventricular repair was defined as takedown to a univentricular repair, cardiac transplantation, and/or death (n=14; 19%). This group was compared with the patients who survived a biventricular approach (n=58). Multiple categorical, morphometric and calculated variables were examined on the basis of the initial echocardiograms. By multivariate analysis, predictors of failure included moderate/large ventricular septal defect (OR=22, P=0.001), unicommissural aortic valve (OR=16, P=0.006), and lower mitral valve dimension z-score (OR=2.2, P=0.02) or lower left ventricular end-diastolic volume z-score (OR=1.9, P=0.03).

CONCLUSIONS

Moderate/large ventricular septal defect, unicommissural aortic valve, and hypoplastic mitral valve or left ventricle are independent risk factors for failure of biventricular repair for infants with multiple left heart obstructive lesions. Combinations of these risk factors may be useful in selecting surgical strategy.