Orthotopic heart transplantation in children with congenital heart disease

Pediatric heart transplantation: Looking forward after five decades of learning

Heart transplantation has become the standard of care for pediatric patients with end-stage heart disease throughout the world. Since the first transplant was performed in 1967, the number of transplants has grown dramatically with 13 449 pediatric heart transplants being reported to The International Society of Heart and Lung Transplant (ISHLT) between January 1992 and June 30, 2018. Outcomes have consistently improved over the last few decades, specifically short-term outcomes. Most recent survival data demonstrate that recipients who survive to 1-year post-transplant have excellent long-term survival with more than 60% of those who were transplanted as infants being alive 25 years later. Nonetheless, the rates of graft loss beyond the first year have remained relatively constant over time; driven primarily by our poor understanding and lack of treatments for chronic allograft vasculopathy (CAV). Acute rejection, CAV, graft failure, and infection continue to be the major causes of death within the first 5 years post-transplant. In addition, renal dysfunction, malignancy, and the need for re-transplantation remain as significant issues that require close follow-up. Looking forward, key challenges include improving donor utilization rates (including donation after cardiac death (DCD) and the use of ex vivo perfusion devices), the development of non-invasive biomarkers for rejection, efforts to mitigate the long-term effects of immunosuppression, and prevention of CAV. It is not possible to cover the entire evolution of pediatric heart transplantation over the last five decades, but in this review, we hope to touch on key observations, lessons learned, and practice changes that have advanced the field, as well as glance ahead to the next decade.

Heart transplantation in biventricular congenital heart disease: indications, techniques, and outcomes

Heart transplantation is an accepted therapeutic modality for end-stage congenital heart disease for both biventricular and univentricular anomalies. Many transplant centers have pushed the limits of transplantation to include patients with high pulmonary vascular resistance, high panel reactive antibodies, positive cross-matches, and ABO-incompatibility. Excellent results have been possible, particularly with the development of improved diagnostic and therapeutic algorithms to prevent and treat rejection, infection, and post-transplant lymphoproliferative disease. Late graft failure and chronic rejection remain vexing problems. The vast majority of patients with biventricular congenital heart disease have undergone prior cardiac surgical procedures. Indications for transplantation in this subgroup are primarily progressive refractory heart failure following prior cardiac surgical reconstructive procedures. Contraindications to transplantation mimic those for other forms of end-stage heart disease. A determination of pulmonary vascular resistance is important in listing patients with biventricular congenital heart disease for heart transplantation. Modifications in the implant technique are necessary and vary depending on underlying recipient anatomy. Risk factors for perioperative outcomes in patients with biventricular congenital heart disease include the need for reoperation, the degree of anatomic reconstruction necessary during the implant procedure, and the degree of antibody sensitization, in addition to a number of other recipient and donor factors. Postoperative outcomes and survival are very good but remain inferior to those with cardiomyopathy in most series. In conclusion, patients with end-stage biventricular congenital heart disease represent a complex group of patients for heart transplantation, and require careful evaluation and management to ensure optimal outcomes.

Impact of pulmonary hypertension on transplant outcomes in pediatric cardiomyopathy patients

Controversy exists over whether PHTN in heart transplant candidates increases post-transplant mortality. We performed analysis of data reported to UNOS for children who underwent primary heart transplantation for cardiomyopathy from January 1994 to June 2010. Patients were divided into two groups depending on their pre-transplant TPG: no-PHTN (TPG ≤ 12 mmHg) and PHTN (TPG >12 mm Hg). A total of 6139 children underwent transplantation of whom 2456 (40%) were for cardiomyopathies; 1322 (54%) of these had catheterization data available. The PHTN group (mean TPG 19.5 ± 8.6) had 312 patients and no-PHTN (TPG 6.7 ± 4.0) had 1010. Mortality at one month (4.5% vs. 2.3%) and three months (6.1% vs. 3.1%) post-transplant was significantly higher in the PHTN than the no-PHTN group with an odds ratio of 2 (p < 0.05). There was no significant effect of PHTN on early mortality in children <1 yr age. There was no significant improvement in early survival for transplants performed after compared to before 2003 in patients with PHTN despite availability of pulmonary dilators. Pre-transplant PHTN increases early post-transplant mortality in pediatric cardiomyopathy patients above one yr of age. There has been no significant improvement in the outcome of this group over the last seven yr.

Infections in Pediatric Solid Organ Transplant Recipients

Infectious complications are an important cause of morbidity and mortality in children undergoing solid organ transplantation. Knowledge gained over the last 30 years provides a growing understanding of these infections. This review identifies risk factors for and timing of infections describes the common infectious syndromes and pathogens seen in children undergoing solid organ transplantation, and reviews preventive strategies.

Heart Transplantation for Congenital Heart Disease

Congenital heart disease affects 0.8% of all live-born infants. Some of the malformed hearts can at best be palliated by conventional surgical or catheter interventions from the start. Others fail slowly from chronic overloading. Patients with congenital heart disease have been among the first transplant recipients since 1967. Primary therapy with infant heart transplant is a convincing concept from an immunological perspective but large-scale implementation is limited by donor organ shortages. Another growing area is rescue therapy for older patients with end-stage heart failure after palliative procedures, particularly those with single-ventricle hearts, systemic right ventricles, and associated arrhythmias.

Outcomes following more than two decades of paediatric cardiac transplantation

OBJECTIVE

There have been significant changes in the field of paediatric cardiac transplantation over the last two decades. We report experience of over 22 years from a single UK transplant centre.

METHODS

A total of 189 orthotopic cardiac transplants were performed in 182 children aged <18 years between March 1987 and March 2009 in our institution. Patients were identified and outcomes reviewed using the cardiopulmonary transplant database and hospital medical records.

RESULTS

182 patients underwent cardiac transplantation, mean age 8.3 years (0.1-17.9 years), 91 (50%) male. Mean follow-up time was 9.0 years (0.3-22.3 years). 117 patients (64%) had a diagnosis of cardiomyopathy, 65 (36%) had congenital heart disease. There was no significant difference in age at transplant between the group with cardiomyopathy and the group with congenital heart disease. 32 patients (17.6%) were on mechanical support prior to transplant. Three (1.6%) patients have required long-term renal replacement therapy post transplant, and 16 (8.8%) developed post-transplant lymphoproliferative disease. Survival was 93% at 30 days, 89% at 1 year, 85% at 5 years, 70% at 10 years and 67% at 15 years with a decrease in mortality over time. Seven patients (3.8%) were re-transplanted.

CONCLUSIONS

Outcomes following cardiac transplantation in childhood are improving with increased experience. There has been a reduction in 30-day mortality over time.

Infections in pediatric transplant recipients: not just small adults

Transplantation increasingly is being used as treatment for children with end-stage organ diseases, hematopoietic rescue from therapy used to treat malignancies, and as cure for primary immune deficiencies. This article reviews some of the major concepts regarding infections that complicate pediatric transplantation, highlighting differences in epidemiology, evaluation, treatment and prevention for children compared with adult recipients.

Late outcomes of pediatric heart transplantation are independent of pre-transplant diagnosis and prior cardiac surgical intervention

BACKGROUND

An increasing number of children are being referred for cardiac transplantation after (1) failing conventional corrective or palliative surgical reconstruction, (2) after stabilization with mechanical circulatory support devices, and (3) when primary graft failure or advanced cardiac allograft vasculopathy are established.

METHODS

The records of 417 infants and children (age range, 0-18 years) who underwent cardiac transplantation from November 1985 through December 2005 at Loma Linda University Children's Hospital were retrospectively reviewed. The pre-transplantation diagnosis was used to divide patients into 3 groups: primary cardiomyopathy (CM), 103; hypoplastic left heart syndrome (HLHS), 154; and other complex congenital heart disease (CCHD), 160. These groups were compared and analyzed for differences in early and late morbidity and mortality.

RESULTS

Operative mortality was significantly lower in the CM group compared with the HLHS (p < 0.02;) and CCHD groups (p < 0.01). Long-term actuarial recipient survival, however, was similar for all groups. The 15-year actuarial survival was 59% for the CM Group, 57% for the HLHS Group, and 50% for the CCHD Group. Actuarial survival after retransplantation is not statistically different from that with primary cardiac transplantation.

CONCLUSION

Although peri-operative survival was lower in infants and children with HLHS and CCHD compared with those with CM, long-term survival has been the same for all groups. Late survival after retransplantation was not statistically different than among those with primary cardiac transplantation.

Outcome for Pediatric Cardiac Transplantation With and Without Bridge Methods

Heart transplantation is indicated for children with end-stage heart failure or complex inoperable congenital defects. Due to the shortage of pediatric donor hearts, various bridge techniques have been used for pediatric recipients to prolong patient survival until a heart is available. This study evaluates long-term outcome of bridge and nonbridge support for pediatric heart transplantation. Between March 1995 and June 2004, 18 pediatric patients underwent heart transplantation. Six patients (33.3%) underwent biological or mechanical bridge techniques before transplantation. Eight patients (44.4%) required perioperatively extracorporeal membrane oxygenation (ECMO) support. Patient data and records were retrospectively reviewed. Causes of death and long-term outcome were analyzed. Five of eight patients in the ECMO group (62.5%) were successfully decannulated and discharged home with excellent functional classes. No differences in rejection rate, survival rate, and functional class existed between the bridged and nonbridged groups. Overall 1-year and 5-year survival rates were both 83.3% and all have a good functional class. Pediatric heart transplantation can be accomplished with excellent early survival despite multiple prior cardiac operations and relatively severe illness. For the variety in small, low-body-weight pediatric patients, mechanical circulatory support using ECMO is suitable for managing sudden collapse while waiting for heart transplantation, and graft dysfunction after cardiac transplantation. The mortality rate is acceptable in this very high-risk group of patients and long-term outcome is good.

Heart and lung transplantation in children

During the past two decades, several advances have resulted in marked improvement in medium-term survival for infants and children undergoing heart transplantation. Unfortunately, progress has been less dramatic in the field of lung and heart-lung transplantation, where there is little evidence of improved outcomes. The procedures remain palliative and all transplant recipients are at risk for the adverse effects of non-specific immunosuppression, including infections, lymphoproliferative disorders, and non-lymphoid malignancies. In addition, current immunosuppressive agents have narrow therapeutic windows and exhibit a wide array of organ toxicities, posing special challenges for the young patient who must endure life-long immunosuppression. New immunosuppressive regimens have lowered the rates of acute rejection but appear to have had relatively little impact on the incidence of chronic rejection, the principal cause of late graft loss. The ultimate goal is to induce a state of donor-specific tolerance, wherein the recipient will accept the allograft indefinitely without the need for long-term immunosuppression. This quest is currently being realised in animal models of solid organ transplantation, and offers great hope for children undergoing heart and lung transplantation in the future.

Anesthesia Considerations for Pediatric Thoracic Solid Organ Transplant

This article discusses the indications, perioperative management, postoperative complications, and patient outcome of pediatric heart transplantation and pediatric lung transplantation. Special emphasis is placed on the anesthetic considerations relevant for children who are undergoing or have received a solid thoracic organ transplant.

Ascending Aortic Aneurysm After Pediatric Heart Transplantation: Case Report of an Unusual Complication

A 28-month-old boy, weighing 11 kg, with severe dilated cardiomyopathy, was transplanted on December 1995. Hypertension and supraventricular tachycardia were detected in the immediate post-operative period, with favorable outcome. After 5 months of clinically asymptomatic follow-up, a dilation in the ascending aorta was observed on routine echocardiogram. Nuclear magnetic resonance imaging (NMRI) confirmed an ascending aortic aneurysm, with a diameter of 38 mm. An operation was performed, a bovine pericardium patch was sutured with reconstruction of the aortic wall, excluding the aneurysm. Good recovery was obtained and the child was discharged on Day 7 postoperatively. A post-operative echocardiogram showed absence of the aortic aneurysm and good surgical results. Another NMRI was done 5 months later, showing an intact ascending aorta. After 64 months, the patients clinical condition was confirmed as normal by echocardiogram. Surgical treatment was successful and the positive results have been maintained.

Effect of oversizing cardiac allografts on survival in pediatric patients with congenital heart disease

BACKGROUND

There are few published data regarding the long-term outcome of "large" cardiac allografts in children. This study examines the effect of cardiac graft oversizing on the survival of pediatric patients with congenital heart disease (CHD).

METHODS

Two hundred ninety-one children, age 1 day to 17 years (median 50 days), with CHD underwent primary cardiac transplantation between 1985 and 2002. Patients were analyzed according to donor-recipient weight ratio (D-R): Group (Gp) I (n = 252) with D-R <2.5 (range 0.59 to 2.49, median 1.4), and Gp II (n = 39) with D-R >/=2.5 (range 2.5 to 4.65, median 2.78). CHD diagnoses included hypoplastic left heart syndrome (138 in Gp I, 13 in Gp II), single ventricle (29 in Gp I, 1 in Gp II) and other (85 in Gp I, 13 in Gp II). Patients with cardiomyopathy were excluded. Pre-transplant cardiac palliation was performed in 36% of Gp I and 15% of Gp II patients. The average graft ischemic times (minutes) were 266 +/- 7.5 and 283 +/- 18.9 for Gp I and Gp II, respectively (p < 0.2).

RESULTS

The operative mortality for Gp I was 10.3% and 10.2% for Gp II (p < 0.99). There was no significant difference between the 2 groups in length of hospital stay (p < 0.15) or duration of ventilator support (p < 0.6) post-transplantation. However, the incidence of open chest was higher (p < 0.003) in Gp II (28%) compared with Gp I (8%). The survival rates for Gp I and Gp II were: 82 +/- 2.4% vs 84 +/- 5.7% at 1 year; 71 +/- 2.9% vs 72 +/- 7.2% at 5 years; and 63 +/- 3.2% vs 65% +/- 7.4 at 10 years.

CONCLUSIONS

Post-transplant morbidity and short- and long-term survival of pediatric recipients with CHD are not adversely influenced by the use of oversized cardiac allografts.

Heart transplantation to a physiologic single lung in patients with congenital heart disease

BACKGROUND

Heart-lung transplantation has been recommended for patients with end-stage congenital heart disease (CHD) and single-lung physiology due to either discontinuous pulmonary arteries (PAs) and unilateral PA hypertension (HTN) or absence of 1 PA.

METHODS

Eleven patients with CHD and single-lung physiology underwent heart transplantation (HT). Diagnoses included: tetralogy of Fallot, absent left PA (n = 4); single-ventricle s/p classic Glenn (n = 7), with absent left PA (n = 1); and severe left PA HTN (n = 6).

RESULTS

Mean time from last surgery was 13 +/- 8 years; mean number of operations (op) was 3.2 +/- 1.7. Mean age was 21 +/- 11 years (range 9.5 to 43). Complications and procedures before HT included hemoptysis (n = 2), plastic bronchitis (n = 1) and interventional catheterization (n = 6). Mean cardiopulmonary bypass and ischemic time was 275 +/- 72 and 268 +/- 75 minutes, respectively. Mean time to extubation was 4.6 +/- 3.2 days, and mean length of stay was 19 +/- 7 days. Post-operative morbidity included bleeding (n = 4), vocal cord paralysis (n = 1) and coil embolization of aortopulmonary collaterals (n = 3). Early post-operative survival was 82%. Cause of death was aortic rupture (n = 1) and bleeding (n = 1). Eight patients are alive 4 years (range 0.9 to 7.6) after HT. PA continuity was established in 6 patients; post-HT lung perfusion scan showed no increase in perfusion to the left PA. One patient died from rejection 3 years post-HT.

CONCLUSIONS

HT can be performed successfully in patients with single-lung physiology. HT is the procedure of choice in patients with end-stage CHD and a physiologic single lung.

Trends and Outcomes in Transplantation for Complex Congenital Heart Disease: 1984 to 2004

BACKGROUND

Cardiac transplantation for patients with complex congenital heart disease poses several anatomic and physiologic challenges for the transplant surgeon. We undertook the current single center study to evaluate surgical outcomes and lessons learned through a nearly twenty year experience with cardiac transplantation for complex congenital heart disease.

METHODS

A retrospective review was performed to evaluate all patients undergoing cardiac transplantation from January 1, 1984 through January 1, 2004. Donor and recipient demographic and intraoperative and postoperative variables were acquired and correlated with perioperative (30-day) and late mortality in both univariate and multivariate analyses, and with Kaplan-Meier survival estimates.

RESULTS

One hundred and six patients underwent transplantation for complex congenital heart disease and were followed for a median of 56 months. Thirty-seven (34.9%) patients died. Male gender and later year of transplantation were protective, and neonatal age and pulmonary artery reconstruction detrimental in multivariable modeling of overall mortality. Transplantation to a physiologic or anatomic single lung did not impact on survival. Patients in the study cohort had comparable survival estimates when compared with all those in the entire cohort without complex congenital heart disease. When comparing patients by era of transplantation, both cohorts demonstrated improved survival with later transplantation.

CONCLUSIONS

Outcomes with transplantation for complex congenital heart disease have improved annually over the past twenty years. Transplantation to an anatomic or physiologic single lung did not impair overall survival. Pulmonary artery reconstruction imparted an increase in mortality both short and long term, a finding which merits further investigation.

Current status of heart transplantation in children: update 2003

Heart transplant is an effective therapy for children with end-stage heart disease. Success of this treatment depends on coordination and careful communication among the family, primary care physician, and transplant team. Primary care physicians play an essential role in the monitoring and management of the medical, nutritional, developmental, and psychosocial issues of pediatric heart transplant patients and their families (Box 3). Ongoing assessment of the child and parent's progress in adapting to transplant is crucial in order for appropriate referrals to occur. Relationships with the primary care team can improve medical outcomes for this complex group of patients and provide a framework for improved adherence to care.

Orthotopic heart transplantation for congenital heart disease: an alternative for high-risk fontan candidates?

OBJECTIVE

Evaluation of incremental risk factors for early mortality in children undergoing orthotopic heart transplantation (OHT) for congenital heart disease.

METHODS

Between 1988 and 2002, 43 patients (mean age 9.1+/-7.2 years) underwent 44 OHT for complex TGA (6), DORV (4), single ventricle (21), and other end-stage structural heart disease (11). Two discernible ventricular chambers were present in 18 pts (41.8%). Previous reconstructive or palliative procedures had been previously accomplished in 35 pts (83.3%), including atrial switch (5), systemic-to-pulmonary shunts (10), cavopulmonary anastomosis (9), Fontan completion (6), and others (5).

RESULTS

30-day survival for the 2-ventricle subgroup was 94.4+/-5.4% compared with 67.2+/-9.5% for the single ventricle subgroup (P=0.04) (overall 78.6%+/-3.3%). OHT following single ventricle staging to bi-directional cavopulmonary anastomosis exhibited 100% early survival, as opposed to 62.5+/-17.1% for OHT after systemic-to-pulmonary shunts, and 33.3+/-19.2% for OHT following failing Fontan (P=0.010). HLHS diagnosis (0.0085) and failing Fontan (P=0.003) were identified as independent predictors of early mortality by regression logistic modeling, while Fontan stage represented the only predictor of overall mortality by Cox proportional hazard. Overall 10-year survival was 54.3+/-11%.

CONCLUSIONS

OHT for structural congenital heart disease with single ventricle physiology entails substantial early mortality and bi-directional cavopulmonary anastomosis enables the best transition to heart transplant. OHT should be considered in the decision making process as an alternative to Fontan completion in high-risk candidates, since rescue-OHT after failing Fontan seems unwarranted.

Pediatric heart and lung transplantation

During the last two decades, several advances have resulted in marked improvement in medium-term survival with excellent quality of life in pediatric heart transplant recipients. These were possible due to better donor and recipient selection, increased surgical experience in transplantation for complex congenital heart disease, development of effective rejection surveillance, and wider choice of immunosuppressive medications. Despite all of these advances, recipients suffer from the adverse effects of non-specific immunosuppression including infections, post-transplant lymphoproliferative disorders and other malignancies, renal dysfunction and other important end-organ toxicities. Furthermore, newer immunosuppressive regimens appear (so far) to have had relatively little impact on the incidence of allograft coronary vasculopathy (chronic rejection). Progress in our understanding of the immunologic mechanisms of rejection and graft acceptance should lead to more targeted immunosuppressive therapy and avoidance of non-specific immunosuppression. The ultimate goal is to induce a state of tolerance, wherein the recipient will accept the allograft indefinitely without the need for long-term immunosuppression and yet remain immunocompetent to other antigens. This quest is currently being realized in many animal models of solid organ transplantation and offers great hope for the future.

The current state of, and future prospects for, cardiac transplantation in children

During the last two decades, several advances have resulted in marked improvement in medium-term survival, with excellent quality of life, in children undergoing cardiac transplantation. Improved outcomes reflect better selection of donors and recipients, increased surgical experience in transplantation for complex congenital heart disease, development of effective surveillance for rejection, and wider choice of immunosuppressive medications. Despite all of these advances, recipients continue to suffer from the adverse effects of non-specific immunosupression, including infections, induction of lymphoproliferative disorders and other malignancies, renal dysfunction, and other important end-organ toxicities. Furthermore, newer immunosuppressive regimes, thus far, appear to have had relatively little impact on the incidence of chronic rejection. Progress in our understanding of the immunologic mechanisms of rejection and graft acceptance should lead to more targeted immunosuppressive therapy and avoidance of non-specific immunosupression. The ultimate goal is to induce a state of tolerance, wherein the recipient will accept the allograft indefinitely, without the need for long-term immunusupression, and yet remain immuno-competent to all non-donor antigens. This quest is currently being realized in many animal models of solid organ transplantation, and offers great hope for the future.

Immunosuppression for pediatric cardiac transplantation in the modern era

With the advent of the T cell activation inhibitors such as cyclosporine, heart transplant success rates for pediatric patients have improved to the point that the initially restricted ages and indications have expanded considerably. Currently the half-life (50% still alive) for children transplanted in the early 1980s is approximately 12-14 years. Decades-long survival seems likely. Components and functions of the immune system are naïve and change during postnatal development. Maturation occurs not only in the first years of life, but well through adolescence and even into adult life. These age-dependent changes within the immune system greatly complicate any attempt to assess immune implications for the use of immunosuppression in children. Since the introduction of cyclosporine, immunosuppression regimens have been virtually unchanged through the 1990s. Recently, there have been significant new immune pharmacological agents which are now commercially available, or still in investigational stages of development. The new maintenance immunosuppressive drugs are either inhibitors of de novo synthesis of nucleotides (purines or pyrimidines), or are immunophilin-binding drugs that inhibit signal transduction in lymphocytes. The newer inhibitors of de novo nucleotide synthesis include mycophenolate mofetil, mizoribine, brequinar and leflunomide. The immunophilin-binding drugs are cyclosporine, tacrolimus and rapamycin. Antibody preparations such as ATG, ATGAM and OKT3, as well as the newer biological agents, which specifically bind to the IL-2 receptor, basiliximab and daclizumab, are discussed. The potential for biologicals which inhibit co-stimulation are also discussed. There may be dramatic changes in protocols used clinically as a result of these new agents over the next decade. The increasing understanding of the alloimmune response as well as the clinical use of these newer drugs promise even better long-term results.

Pulmonary hypertension in pediatric heart transplantation

Pulmonary hypertension can pose a significant problem in the management of children with congestive heart failure. Assessment of pulmonary artery anatomy, pressures and (when possible) pulmonary vascular resistance is critically important in the evaluation of these children when they are under consideration for heart transplantation. Severe, fixed elevation of the pulmonary vascular resistance is a contraindication to heart transplantation because of concerns of acute post-transplant donor right ventricular failure. However, even modest degrees of pulmonary hypertension can complicate the post-operative management of pediatric heart transplant recipients. This review will provide information regarding the recognition, diagnosis, and pre-operative and post-operative management of pulmonary hypertension in patients under consideration for heart transplantation.

Preoperative assessment and management of pediatric heart transplantation

The period of preoperative management of the pediatric cardiac transplant patient can be divided into three phases: determination of transplant feasibility, listing, and medical management. Chronic infection, irreversible elevation of pulmonary vascular resistance, and intractable disease in other organ systems may all be contraindications for transplantation. The United Network for Organ Sharing has recently changed its listing guidelines. Adolescent donors are now preferentially, to some extent, allocated to adolescent recipients. Management of pediatric patients awaiting cardiac transplantation encompasses optimization of cardiac output through the use of vasodilators and oral and intravenous inotropic agents. For those patients listed for transplantation who have single ventricle lesions, such as hypoplastic left heart syndrome, management of heart failure also includes balancing systemic and pulmonary blood flows. Mechanical support of the circulation with extracorporeal membrane oxygenation or ventricular assist devices can be used as a bridge to transplant in pediatric patients.

Heart transplantation in children: indications. Report of the Ad Hoc Subcommittee of the Pediatric Committee of the American Society of Transplantation (AST)

This review details the indications for heart transplantation in children. Contraindications have evolved from absolute to relative. Controversial issues remain and this paper represents a consensus of more than a dozen centers that have programs that remain active performing pediatric heart transplants.

Current results with pediatric heart transplantation

BACKGROUND

Cardiac transplantation is an accepted treatment for children with end-stage heart failure or complex or inoperable congenital defects.

METHODS

Since 1988, 95 transplants have been performed in 89 children aged 4 days to 18 years (median 6.9 years, 42 patients 0-5 years). Fifty-eight (61%) had congenital or acquired heart disease, 31 (33%) had idiopathic cardiomyopathy, and 6 (6%) were retransplants. Fifty-seven of the patients had prior cardiac surgery with a range of one to eight procedures (mean 3.4 procedures/patient). At the time of transplantation, 53 (56%) were United Network for Organ Sharing (UNOS) status I, including 23 children on mechanical ventilation and 4 with mechanical circulatory support.

RESULTS

Thirty-day survival in this group was 96%. Posttransplant results showed a median time of ventilation of 1 day (mean 3.0+/-5.7 days), median duration of inotropic support of 2 days (mean 2.7+/-2.3 days), median intensive care unit (ICU) stay of 4 days (mean 6.9+/-9.6 days), and median hospitalization of 9 days (mean 14.3+/-13.9 days). Follow-up from 1 month to 10.3 years (mean 3.1 years) has demonstrated a 1-year actuarial survival of 79% and a 5-year actuarial survival of 69%. Rejection, both acute and chronic, accounted for the vast majority of deaths.

CONCLUSIONS

Pediatric heart transplantation can be accomplished with excellent early survival despite multiple prior cardiac operations and relative severity of illness. Parameters such as postoperative ventilation, inotropic support, ICU stay, and hospitalization can be kept at reasonable levels with acceptable long-term results, although rejection remains a serious problem.

Cardiac transplantation for end-stage congenital heart defects: the Mayo Clinic experience. Mayo Cardiothoracic Transplant Team

OBJECTIVE

To review the outcome of cardiac transplantation undertaken in patients with congenital heart defects.

MATERIAL AND METHODS

Between November 1991 and March 1998 at our institution, cardiac transplantation was performed in 16 patients with congenital heart disease (age range, 3 to 57 years; mean, 26.1). Preoperative diagnoses included univentricular heart (N = 4); complete transposition of the great arteries (N = 3); Ebstein's anomaly (N = 2); tetralogy of Fallot (N = 2); levotransposition (N = 2); dextrocardia, corrected transposition, ventricular and atrial septal defects, and pulmonary stenosis (N = 1); double-outlet right ventricle (N = 1); and hypertrophic obstructive cardiomyopathy (N = 1). All patients had undergone from one to five previous palliative operations.

RESULTS

Four patients required permanent pacemaker implantation during the first month postoperatively because of bradycardia; more than 2 years later, another patient required a permanent pacemaker because of sick sinus syndrome. In addition, one patient had an automatic implantable cardioverter-defibrillator. Three patients required reconstruction of cardiovascular structures with use of prosthetic material (Teflon patches or donor tissue) at the time of cardiac transplantation. Actuarial 1-, 2-, and 5-year survival was 86.2 +/- 9.1%. During the first year after transplantation, two deaths occurred--one at 41 days of putative vascular rejection and the second at 60 days of severe cellular rejection. All other patients are alive and functionally rehabilitated; the mean follow-up period has been 26.1 months (range, 2 to 89.6).

CONCLUSION

Cardiac transplantation for patients with congenital heart disease can be accomplished with a low perioperative mortality and an excellent medium-term survival despite the challenges presented by the technical difficulties during invasive diagnostic procedures and at operation and the need for adherence to long-term multiple-drug therapy in this patient population.

Infant heart transplantation: improved intermediate results

OBJECTIVES

Our objectives were to (1) review our experience with heart transplants in infants (age < 6 months), (2) delineate risk factors for 30-day mortality, and (3) compare outcomes between our early and recent experience.

METHODS

Records of all infants listed for transplantation in our center before September 1996 were analyzed. Early and recent comparisons were made between chronologic halves of the accrual period. Univariate analysis was used to analyze potential risk factors for 30-day mortality (categorical variables, Fisher's exact test; continuous variables, nonparametric Wilcoxon rank-sum test). Multivariable analysis included univariate variables with p values < or = 0.10. Actuarial survivals were estimated (Kaplan-Meier) and compared by the log-rank test.

RESULTS

Fifty-one of the 60 infants listed for transplantation were operated on (waiting list mortality 15%). Thirty-day mortality was 18% overall, 30% in the first 3 years and 10% in the last 3 years (p = 0.07). Sepsis was the commonest cause of early death (4/9). Univariate analysis suggested four potential risk factors for early death: preoperative mechanical ventilation (p = 0.01), prior sternotomy (p = 0.002), preoperative inotropic drugs (p = 0.08), and warm ischemia time (p = 0.08). Multivariable analysis indicated that prior sternotomy (p = 0.01) was an independent risk factor for 30-day mortality. Actuarial survivals were 80%, 78%, and 70% at 1, 2, and 3 years, and these figures improved between early and recent groups (p = 0.05). Late deaths were most commonly due to acute rejection (3/5).

CONCLUSIONS

Results of heart transplantation in infancy improve with experience. Prior sternotomy increases initial risk. Intermediate-term survival for infants with end-stage heart disease is excellent.

Orthotopic cardiac transplantation for the failing Fontan circulation

OBJECTIVE

Modified Fontan procedures are now employed in several conditions unsuitable for bi-ventricular repair. Selection criteria have been relaxed. The procedure is palliative. Longterm outlook is unknown. This study evaluated factors associated with the development of a failing Fontan circulation and transplantation results.

METHODS

Retrospective review of patients referred to a single centre for cardiac transplant assessment.

RESULTS

Between 1985 and 1996, 46 of 448 cardiac transplants were performed for congenital heart disease. Nine of these were performed in patients with a failing Fontan circulation (four adults, five children). In six cases, the dominant ventricle had left ventricular (LV) morphology. Congenital anomalies included double outlet right ventricle (three cases), double inlet left ventricle (two cases), tricuspid atresia (two cases), and pulmonary atresia with intact ventricular septum (one case). Fontan procedures were performed in absence of sinus rhythm (four cases), atrio-ventricular (AV) valve regurgitation (two cases), aortic regurgitation and systolic LV dysfunction (one case), elevated mean pulmonary artery pressure (one case), and older age (>7 years, eight cases). Three patients required early re-operation and two needed permanent pacing. Subsequent deterioration associated with loss of sinus rhythm (four cases) and progressive AV valve regurgitation (seven cases) led to transplant assessment (at < 1 year, five cases; at 2-12 years, four cases). All patients were listed for transplantation. Three patients required intravenous inotropic support and three patients with lymphocytotoxic antibodies needed prospective crossmatching. Donor cardiectomy was modified to facilitate implantation. The recipient operation involved pulmonary artery reconstruction (using pericardium), modified atrial and direct caval anastomoses. Three patients died within 24 h of surgery (two graft failures, one haemorrhage). In operative survivors (n = 6), intensive care stay was 3-16 days, and hospital stay ranged from 14 to 32 days. There have been no subsequent deaths (follow up, 0.5-4.7 years).

CONCLUSION

In high-risk Fontan candidates, transplantation may be preferable at the outset. Previous surgery, lymphocytotoxic antibodies, indeterminate pulmonary vascular resistance, emergency status, sub-optimal donor selection, and perioperative bleeding contribute to peri-operative mortality. In survivors, the outcome remains very encouraging.

Long-term results of triple-drug-based immunosuppression in nonneonatal pediatric heart transplant recipients

BACKGROUND

Few reports document long-term results of pediatric cardiac transplantation in which triple therapy (cyclosporine, azathioprine, and corticosteroids) was the mainstay of immunosuppression. This report details a single center's pediatric transplant experience and analyzes the relative contributions of selected pre/posttransplant risk factors on long-term morbidity and mortality.

METHODS

Retrospective data were collected for all non-neonatal pediatric transplant recipients including: presenting diagnosis, cardiac hemodynamics (particularly pulmonary vascular resistance index), donor ischemic time, occurrence of postoperative infections, episodes of allograft rejection, incidence of posttransplant lymphoproliferative disease or coronary artery disease (CAD), and overall survival. Analysis of single variables and a Cox-proportional hazards model were utilized to determine the impact of pre/posttransplant risk factors on long-term survival.

RESULTS

From 1984 to 1995, 64 patients (mean age, 8.3 years), 46 of whom had cardiomyopathy and 18 who had inoperable complex congenital heart disease, underwent cardiac transplantation and received triple-drug immunosuppression. Orthotopic transplantation was performed unless the pulmonary vascular resistance index remained >6 um2 (despite use of pulmonary vasodilator). One patient required heterotopic transplantation. Average donor ischemic time was 217 min. An average of 1.2 rejection episodes/patient occurred (average follow-up period: 50 months). No patient developed posttransplant lymphoproliferative disease, but 22 patients (34%) developed CAD. Overall survival was 80%, 60%, and 57% at 1, 5, and 10 years, respectively. Of outcome variables analyzed, rejection frequency was significantly increased in patients who subsequently developed CAD, but the presence of CAD was not significantly correlated with mortality.

CONCLUSION

Triple-drug-based immunosuppressive maintenance therapy in pediatric heart transplant recipients results in good long-term graft survival.

Long-term survivors of pediatric heart transplantation: a multicenter report of sixty-eight children who have survived longer than five years

OBJECTIVE

Short-term survival after pediatric heart transplantation is now excellent, but ultimately the efficacy of this procedure will depend on duration and quality of survival. We sought to evaluate the clinical course of long-term survivors of heart transplantation in childhood.

METHODS

Patients who had undergone heart transplantation at the university hospitals of Stanford, Columbia, and Pittsburgh between 1975 and 1989 and survived longer than 5 years from transplantation were identified and their clinical courses retrospectively reviewed.

RESULTS

Sixty eight children have survived more than 5 years from transplantation, and 60 (88%) are currently alive with a median follow-up of 6.8 years (5 to 17.9 years). Thirteen have survived more than 10 years from transplantation. Renal dysfunction caused by immunosuppressive agents was common, and two patients required late renal transplantation. Lymphoproliferative disease or other neoplasm occurred in 12 patients, but none resulted in death. Coronary artery disease was diagnosed in 13 patients (19%), leading to retransplantation in eight. Death after 5 years was related to acute or chronic rejection in 5 of 8 cases. Two of the deaths were directly related to noncompliance with immunosuppressive medication. All survivors are in New York Heart Association class 1.

CONCLUSIONS

Long-term survival with good quality of life can be achieved after heart transplantation in childhood, though complications of immunosuppression remain common. Posttransplantation coronary artery disease is emerging as the main factor limiting long term graft and patient survival.

Transplantation as a primary treatment for hypoplastic left heart syndrome: intermediate-term results

BACKGROUND

Hypoplastic left heart syndrome is a lethal malformation. For the last 10 years, orthotopic cardiac transplantation has been our preferred treatment for infants with hypoplastic left heart syndrome.

METHODS

One hundred seventy-six infants with hypoplastic left heart syndrome were entered into a cardiac transplant protocol between November 1985 and November 1995. Interventional procedures to stent the ductus arteriosus or enlarge the interatrial communication were performed in 8 and 35 patients, respectively. Thirty-four patients (19%) died during the waiting period, and 142 infants underwent cardiac transplantation. Age at cardiac transplantation ranged from 1.5 hours to 6 months (median, 29 days). The majority of grafts were oversized, and the median graft ischemic time was 273 minutes (range, 60 to 576 minutes). The implantation procedure used a period of hypothermic circulatory arrest ranging from 23 to 110 minutes (median, 53 minutes). Repair of other significant defects included interrupted aortic arch and total or partial anomalous pulmonary venous connection.

RESULTS

There were 13 early and 22 late deaths. Patient actuarial survival at 1 month and at 1, 5 and 7 years was 91%, 84%, 76%, and 70% respectively. Half of the late deaths were due to rejection. Severe graft vasculopathy was confirmed in 8 patients. Retransplantation was performed in 5 patients for graft vasculopathy 4 and rejection 1. Lymphoblastic leukemia developed in 1 patient 3 years after cardiac transplantation.

CONCLUSIONS

Cardiac transplantation can be performed in infants with hypoplastic left heart syndrome with good operative and intermediate-term results. Improved survival can be achieved with increased donor availability, better management of rejection, and control of graft vasculopathy.