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ABSTRACT: Allosensitization among children being considered for heart transplantation remains a great challenge. Controversy exists as to the best approach for those with elevated panel-reactive antibody (PRA) titers. We sought to define the association between elevated PRA and outcomes using data from the multi-institutional Pediatric Heart Transplant Study Group.
Between January 1993 and December 2008, 3,016 patients (>1 month of age) were listed for heart transplantation. PRA data at listing were available for 2,500 (83%) patients, and 2,237 underwent transplantation with PRA data being available for 1,904 (85%). Because various PRA assays were employed (e.g., cell-based and solid phase) we entered the highest value regardless of methodology.
Among the factors associated with high PRA at transplant were Status 1 at listing, previous sternotomy and prior Norwood procedure. An elevated PRA at listing was associated with higher risk of death while waiting. Of subjects with PRA ≥ 50% only 57% were transplanted by 1 year on the waitlist, as compared with 76% of those with PRA <10%. Waitlist mortality for the highly allosensitized subjects (≥ PRA 50%) was 19% by 12 months. Survival at 1 year after transplantation was significantly lower in those with PRA ≥ 50% versus those with PRA <10% (73% vs 90%, respectively, p < 0.0001). Those with elevated PRA who had a negative prospective crossmatch had no difference in survival compared with those without allosensitization. There was no significant association between PRA levels and time to first rejection or development of coronary allograft vasculopathy.
Significant allosensitization is associated with more than a 2-fold increased risk of death within the first transplant year. Although prospective crossmatching abrogates the risk of post-transplant mortality, it may contribute to higher pre-transplant attrition due to longer waitlist times. There is a critical need for strategies to minimize the impact of allosensitization and antibody-mediated rejection immediately after transplantation.
The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 08/2011; 30(11):1221-7. · 3.54 Impact Factor
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ABSTRACT: While the Fontan operation has facilitated the survival of a generation of children born with congenital heart disease resulting in a functional single ventricle, it does not recreate a normal circulation. Over time, survivors of the Fontan operation are at risk for ventricular dysfunction, plastic bronchitis, protein-losing enteropathy and chronic Fontan failure. New techniques and therapies are emerging to address the long-term risks associated with Fontan physiology, but as the number of survivors continues to grow, the recognition of the limitations of this circulation is increasing. Novel investigations of possible mechanical devices designed to function as a subpulmonary ventricle are underway, but are still many years away from clinical use. In the meantime, continued development of medical therapeutics targeted at the specific problems of the Fontan circulation will be beneficial and might reduce the need for cardiac transplantation.
Expert Review of Cardiovascular Therapy 06/2011; 9(6):785-93.
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ABSTRACT: Children and adults with congenital heart disease (CHD) can require interventions that result in immunologic alterations that are different than those seen in patients with cardiomyopathies. Patients with CHD can be exposed to heart surgeries, blood products, valved and non-valved allograft tissue, and mechanical circulatory support, all of which can alter the immunologic status of these patients. This change in immunologic status is most commonly manifested as the development of anti-human leukocyte antigen (HLA) antibodies. This review will delineate a) the causes of anti-HLA anti-body production (often referred to as allosensitization); b) preventive strategies for anti-HLA antibody production before transplantation; c) treatment strategies for those patients who develop anti-HLA antibodies before transplantation; d) consequences of HLA allosensitization after transplantation; and e) treatment of HLA allosensitization and antibody-mediated rejection after transplantation.
Current Cardiology Reviews 05/2011; 7(2):67-71.
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Susan R Foerster,
Charles E Canter,
Amy Cinar,
Lynn A Sleeper,
Steven A Webber,
Elfriede Pahl,
Paul F Kantor,
Jorge A Alvarez,
Steven D Colan,
John L Jefferies,
Jacqueline M Lamour,
Renee Margossian,
Jane E Messere,
Paolo G Rusconi, Robert E Shaddy,
Jeffrey A Towbin,
James D Wilkinson,
Steven E Lipshultz
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ABSTRACT: Myocarditis is a cause of a new-onset dilated cardiomyopathy phenotype in children, with small studies reporting high rates of recovery of left ventricular (LV) function.
The presenting characteristics and outcomes of children with myocarditis diagnosed clinically and with biopsy confirmation (n=119) or with probable myocarditis diagnosed clinically or by biopsy alone (n=253) were compared with children with idiopathic dilated cardiomyopathy (n=1123). Characteristics at presentation were assessed as possible predictors of outcomes. The distributions of time to death, transplantation, and echocardiographic normalization in the biopsy-confirmed myocarditis and probable myocarditis groups did not differ (P≥0.5), but both groups differed significantly from the idiopathic dilated cardiomyopathy group (all P≤0.003). In children with myocarditis, lower LV fractional shortening z-score at presentation predicted greater mortality (hazard ratio, 0.85; 95% confidence interval, 0.73 to 0.98; P=0.03) and greater LV posterior wall thickness predicted transplantation (hazard ratio, 1.17; 95% confidence interval, 1.02 to 1.35; P=0.03). In those with decreased LV fractional shortening at presentation, independent predictors of echocardiographic normalization were presentation with an LV end-diastolic dimension z-score >2 (hazard ratio, 0.36; 95% confidence interval, 0.22 to 0.58; P<0.001) and greater septal wall thickness (hazard ratio, 1.16; 95% confidence interval, 1.01 to 1.34; P=0.04).
Children with biopsy-confirmed or probable myocarditis had similar proportions of death, transplantation, and echocardiographic normalization 3 years after presentation and better outcomes than those of children with idiopathic dilated cardiomyopathy. In children with myocarditis who had impaired LV ejection at presentation, rates of echocardiographic normalization were greater in those without LV dilation and in those with greater septal wall thickness at presentation. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00005391.
Circulation Heart Failure 11/2010; 3(6):689-97. · 6.29 Impact Factor
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ABSTRACT: The management of heart failure in children is becoming a specialized discipline within pediatric cardiology. Unlike the treatment of heart failure in adults, for which an extensive body of literature supports current treatment regimens, management of heart failure in children is largely guided by extrapolation from adult studies and expert opinion. This review focuses on the current state-of-the-art with respect to the outpatient management of heart failure in children.
Heart Failure Clinics 10/2010; 6(4):515-29, ix.
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ABSTRACT: Although decellularized cryopreserved valved allografts (DCAs) have reduced immunogenicity, proof of clinical superiority over standard cryopreserved allografts (SCAs) is lacking. To assess functional results and durability, we studied a group of patients with DCAs implanted between 2000 and 2005 and compared them with a similar group with SCAs.
From July 2000 until January 2005, 47 patients underwent insertion of a DCA between the right ventricle and pulmonary arteries. The DCA patients were compared with 47 age-matched and diagnosis-matched controls receiving SCAs. All patients received pulmonary allografts and were matched for valve position (orthotopic versus heterotopic). We analyzed each group for survival, reoperation, reintervention (surgical or catheter-based), stenosis, and regurgitation.
There were no differences between groups with respect to weight, age, valve size, or survival. Actuarial freedom from reintervention at 8 years was 79% for DCAs as compared with 63% for SCAs (p = 0.31, log-rank). Echocardiogram in the DCA group (median 66 months) showed a slightly lower median peak gradient of 16 mm Hg (range, 0 to 82 mm Hg) as compared with 22 mm Hg (range, 0 to 63) in the SCA group (median 61 months, p = 0.051, Wilcoxon). However, when conduits 18 mm or less in diameter were compared, DCA patients had a median peak gradient of 10 mm Hg (range, 0 to 43) compared with 25 mm Hg in SCAs (range, 0 to 55 mm Hg, p = 0.03). There were no differences in the degree of allograft insufficiency in either group.
Decellularized cryopreserved valved allografts have a nonsignificant trend toward lower peak valve gradient and reintervention in comparison with SCAs. Small valve sizes (18 mm or less) show a slight but significant improvement in peak gradient, but no advantage in valve insufficiency. These findings and a significantly higher cost (>$3,000) make further direct comparisons necessary before widespread use of DCAs can be justified.
The Annals of thoracic surgery 10/2010; 90(4):1301-5; discussion 1306. · 3.74 Impact Factor
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ABSTRACT: The ability of serum B-type natriuretic peptide levels (BNP) to predict outcomes in children with heart failure (HF) has not been well demonstrated. This study was designed to determine whether BNP levels predict outcomes in patients with moderate symptomatic HF.
We investigated whether enrollment BNP levels for the Pediatric Carvedilol Trial were associated with baseline characteristics. Freedom from a composite end point of HF hospitalization, death, or transplantation at 9 months was compared using a threshold BNP level identified using receiver operating curve analysis. Median BNP level was 110 pg/mL (interquartile range, 22.4 to 342.0 pg/mL) in 138 subjects. Median age was 3.4 years (interquartile range, 1.1 to 11.0 years). Diagnoses were cardiomyopathy (60%) and congenital heart disease (40%); 73% had a systemic left ventricle. BNP levels correlated moderately with left ventricular ejection fraction (R=0.39, P<0.001) but did not differ by HF class, age, diagnosis, sex, ventricular morphology, or left ventricular end-diastolic dimension Z-score (R=0.19). Outcome events included 25 HF hospitalizations, 4 deaths, and 2 transplants. Sensitivity was 71% and specificity 63%, for a BNP cutoff value of 140 pg/mL. BNP ≥140 pg/mL (hazard ratio, 3.7; 95% confidence interval, 1.62 to 8.4; P=0.002) and age >2 years (hazard ratio, 4.45; 95% confidence interval, 1.68 to 12.04; P=0.003) were independently associated with worse outcomes.
In children with moderately symptomatic HF, BNP ≥140 pg/mL and age >2 years identified subjects at higher risk for worse outcome. Further validation is needed to determine the BNP levels necessary to stratify risk in other pediatric cohorts.
Circulation Heart Failure 09/2010; 3(5):606-11. · 6.29 Impact Factor
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ABSTRACT: Echocardiography is used to measure the therapeutic effectiveness of heart failure therapy in adults and children. The purposes of this study were (1) to assess baseline echocardiographic predictors of clinical outcome, (2) to investigate changes in echocardiographic parameters, and (3) to compare these echocardiographic changes with changes in plasma levels of b-type natriuretic peptide (BNP) in a population of children with systemic ventricular dysfunction and symptomatic heart failure treated with carvedilol or placebo. All available baseline and 6-month echocardiograms from Pediatric Carvedilol Trial (PCT) participants (carvedilol n = 161; placebo n = 55) were reviewed. Systolic and diastolic sphericity index (SI; n = 110), TEI index (n = 145), and systemic ventricular dP/dt (n = 70) were measured. The PCT composite definition of clinical outcome (i.e., worsened, improved, or unchanged) was used. For all patients, baseline TEI index was a predictor of worsened outcome. Only children treated with carvedilol showed a significant decrease in systolic SI (P B 0.0001), diastolic SI (P B 0.0001), and TEI index (P = 0.02). An inverse correlation between changes in BNP and changes in dP/dt (r = -0.45, P = 0.04) was found only in the carvedilol group. In conclusion, TEI index predicted outcome in children with systemic ventricular dysfunction and heart failure. Carvedilol may have a beneficial effect on reversal of left ventricular remodeling and global ventricular function in pediatric heart failure.
Pediatric Cardiology 04/2010; 31(6):780-4. · 1.30 Impact Factor
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ABSTRACT: Heart failure is becoming an increasingly common and significant problem in the field of pediatric cardiology. The numerous types of cardiomyopathies, and more recently, long-term survival of patients with congenital heart disease, have added to a growing patient population. Over the last several decades, our knowledge base regarding mechanisms of disease and therapeutic intervention in adult patients with heart failure has drastically changed. The most recent and important breakthrough in the pharmacologic treatment of heart failure has been the particular role of β-blocker therapy. This medication has led to significant improvements in survival and symptoms in adults, with less convincing findings in limited studies in pediatrics. The ability to study the benefits of this therapy in patients has been challenging owing to the heterogeneity of the patient population and lack of large sample sizes. However, as we investigate the mechanisms behind the disease process, the differences that exist between disease conditions and ages, and the significant alterations that may exist at the molecular and genetic level, our understanding of β-blocker therapy in pediatric heart failure will improve, and ultimately may lead to patient-specific therapy.
Pediatric Health 01/2010; 4(1):45-58.
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ABSTRACT: Body mass index (BMI) both before and after heart transplant (HT) is used to risk stratify in adult HT. Single-center studies identify BMI as a potential predictor of outcome after HT in children; large-scale analyses in pediatric HT have not been performed.
The ISHLT pediatric heart transplant registry was queried for HT recipients >2 years old between 1996 and 2006 with data for BMI percentile (BMI%ile) at HT. Survival and morbidity rates post-HT were compared between BMI%ile cohorts defined as: wasted, <5th BMI%ile; normal, 5th to 95th BMI%ile; and obese, >95th BMI%ile at HT.
Data from 2,333 pediatric HT patients were available for analysis. Incidence of abnormal BMI%ile at HT was: wasted = 23% and obese = 8%. Wasting and obesity were similar in patients with congenital or cardiomyopathic diagnoses. Wasted or obese patients at HT did not differ from patients with normal BMI in survival on Kaplan-Meier or multivariate analyses. There were no significant differences in pre-, peri- or post-operative adverse events between patients with wasting or obesity and those with normal BMI%ile at HT.
In contrast to adults, abnormal body mass at time of transplant was not associated with decreased survival in pediatric HT recipients. Potential pediatric transplant candidates should not be excluded based on the perception that wasting or obesity will increase the risk of adverse outcomes.
The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 09/2009; 28(12):1273-8. · 3.54 Impact Factor
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Robert E Shaddy
Pediatric Transplantation 05/2009; · 1.48 Impact Factor
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Pediatric Transplantation 03/2009; 13(1):141. · 1.48 Impact Factor
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Cardiology in the Young 01/2009; 18 Suppl 3:63-71. · 0.76 Impact Factor
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Pediatric Transplantation 11/2008; 13(1):141 - 141. · 1.48 Impact Factor
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ABSTRACT: There is a growing population of adult patients with congenital heart defects in the developed world. Most have been repaired, but few have been cured. Many have myocardial dysfunction. Most have exercise intolerance. Some have heart failure. As a group, they show neurohormonal activation similar to that seen in an adult heart failure population with acquired heart disease. Currently, the patients at greatest risk of heart failure are those without a systemic left ventricle, such as Mustard and Senning repairs of transposition of the great arteries (TGA), congenitally corrected TGA, and patients who have had a Fontan procedure. Exercise intolerance may predict hospitalization and death in such patients. For those patients with systemic left ventricles, it would seem reasonable to use the heart failure guidelines developed for patients with acquired heart disease. For those patients without a systemic left ventricle (e.g., a systemic right ventricle or single ventricle), there is currently no foundation for evidence-based therapy.
Expert Review of Cardiovascular Therapy 03/2008; 6(2):165-74.
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Robert E Shaddy,
Mark M Boucek,
Daphne T Hsu,
Robert J Boucek,
Charles E Canter,
Lynn Mahony,
Robert D Ross,
Elfriede Pahl,
Elizabeth D Blume,
Debra A Dodd,
David N Rosenthal,
Jeri Burr,
Bernie LaSalle,
Richard Holubkov,
Mary Ann Lukas,
Lloyd Y Tani
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ABSTRACT: Although beta-blockers improve symptoms and survival in adults with heart failure, little is known about these medications in children and adolescents.
To prospectively evaluate the effects of carvedilol in children and adolescents with symptomatic systemic ventricular systolic dysfunction.
A multicenter, randomized, double-blind, placebo-controlled study of 161 children and adolescents with symptomatic systolic heart failure from 26 US centers. In addition to treatment with conventional heart failure medications, patients were assigned to receive placebo or carvedilol. Enrollment began in June 2000 and the last dose was given in May 2005 (each patient received medication for 8 months).
Patients were randomized in a 1:1:1 ratio to twice-daily dosing with placebo, low-dose carvedilol (0.2 mg/kg per dose if weight <62.5 kg or 12.5 mg per dose if weight > or =62.5 kg), or high-dose carvedilol (0.4 mg/kg per dose if weight <62.5 kg or 25 mg per dose if weight > or =62.5 kg) and were stratified according to whether each patient's systemic ventricle was a left ventricle or not.
The primary outcome was a composite measure of heart failure outcomes in patients receiving carvedilol (low- and high-dose combined) vs placebo. Secondary efficacy variables included individual components of this composite, echocardiographic measures, and plasma b-type natriuretic peptide levels.
There was no statistically significant difference between groups for the composite end point based on the percentage of patients who improved, worsened, or were unchanged. Among 54 patients assigned to placebo, 30 improved (56%), 16 worsened (30%), and 8 were unchanged (15%); among 103 patients assigned to carvedilol, 58 improved (56%), 25 worsened (24%), and 20 were unchanged (19%). The rates of worsening were lower than expected. The odds ratio for worsened outcome for patients in the combined carvedilol group vs the placebo group was 0.79 (95% CI, 0.36-1.59; P = .47). A prespecified subgroup analysis noted significant interaction between treatment and ventricular morphology (P = .02), indicating a possible differential effect of treatment between patients with a systemic left ventricle (beneficial trend) and those whose systemic ventricle was not a left ventricle (nonbeneficial trend).
These preliminary results suggest that carvedilol does not significantly improve clinical heart failure outcomes in children and adolescents with symptomatic systolic heart failure. However, given the lower than expected event rates, the trial may have been underpowered. There may be a differential effect of carvedilol in children and adolescents based on ventricular morphology.
clinicaltrials.gov Identifier: NCT00052026.
JAMA The Journal of the American Medical Association 09/2007; 298(10):1171-9. · 30.03 Impact Factor
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Robert E Shaddy
Cardiology in the Young 09/2007; 17(4):354-5. · 0.76 Impact Factor
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Charles E Canter, Robert E Shaddy,
Daniel Bernstein,
Daphne T Hsu,
Maryanne R K Chrisant,
James K Kirklin,
Kirk R Kanter,
Robert S D Higgins,
Elizabeth D Blume,
David N Rosenthal,
Mark M Boucek,
Karen C Uzark,
Alan H Friedman,
Allen H Friedman,
James K Young
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ABSTRACT: Since the initial utilization of heart transplantation as therapy for end-stage pediatric heart disease, improvements have occurred in outcomes with heart transplantation and surgical therapies for congenital heart disease along with the application of medical therapies to pediatric heart failure that have improved outcomes in adults. These events justify a reevaluation of the indications for heart transplantation in congenital heart disease and other causes of pediatric heart failure.
A working group was commissioned to review accumulated experience with pediatric heart transplantation and its use in patients with unrepaired and/or previously repaired or palliated congenital heart disease (children and adults), in patients with pediatric cardiomyopathies, and in pediatric patients with prior heart transplantation. Evidence-based guidelines for the indications for heart transplantation or retransplantation for these conditions were developed.
This evaluation has led to the development and refinement of indications for heart transplantation for patients with congenital heart disease and pediatric cardiomyopathies in addition to indications for pediatric heart retransplantation.
Circulation 03/2007; 115(5):658-76. · 14.74 Impact Factor
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ABSTRACT: Cryopreserved valved allografts are frequently used in the repair of congenital heart defects in children. Although the longevity of these grafts is generally good in most patients, there continue to be ongoing problems with allograft dysfunction and subsequent failure, particularly in infants and young children. The aim of this review is to discuss the immunogenicity of cryopreserved allograft tissue and measures that may minimize the deleterious effect of the immune system on allograft function and durability.
Expert Review of Cardiovascular Therapy 10/2006; 4(5):695-701.
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Robert E Shaddy
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ABSTRACT: The evidence available from which to guide therapy for pediatric heart failure is limited. Although there are many reasons for this, the greatest obstacles in developing this evidence base are due to the significant challenges inherent in performing well-designed drug trials in pediatric heart failure. This perspective will define many of these obstacles and will propose potential structures for the development and implementation of drug trials in pediatric heart failure.
Future Cardiology 05/2006; 2(3):281-6.
