Francis Fynn-Thompson

Waiting List Mortality Among Children Listed for Heart Transplantation in the United States

Background— Children listed for heart transplantation face the highest waiting list mortality in solid-organ transplantation medicine. We examined waiting list mortality since the pediatric heart allocation system was revised in 1999 to determine whether the revised allocation system is prioritizing patients optimally and to identify specific high-risk populations that may benefit from emerging pediatric cardiac assist devices. Methods and Results— We conducted a multicenter cohort study using the US Scientific Registry of Transplant Recipients. All children <18 years of age who were listed for a heart transplant between 1999 and 2006 were included. Among 3098 children, the median age was 2 years (interquartile range 0.3 to 12 years), and median weight was 12.3 kg (interquartile range 5 to 38 kg); 1294 (42%) were nonwhite; and 1874 (60%) were listed as status 1A (of whom 30% were ventilated and 18% were on extracorporeal membrane oxygenation). Overall, 533 (17%) died, 1943 (63%) received transplants, and 252 (8%) recovered; 370 (12%) remained listed. Multivariate predictors of waiting list mortality include extracorporeal membrane oxygenation support (hazard ratio [HR] 3.1, 95% confidence interval [CI] 2.4 to 3.9), ventilator support (HR 1.9, 95% CI 1.6 to 2.4), listing status 1A (HR 2.2, 95% CI 1.7 to 2.7), congenital heart disease (HR 2.2, 95% CI 1.8 to 2.6), dialysis support (HR 1.9, 95% CI 1.2 to 3.0), and nonwhite race/ethnicity (HR 1.7, 95% CI 1.4 to 2.0). Conclusions— US waiting list mortality for pediatric heart transplantation remains unacceptably high in the current era. Specific high-risk subgroups can be identified that may benefit from emerging pediatric cardiac assist technologies. The current pediatric heart-allocation system captures medical urgency poorly. Further research is needed to define the optimal organ-allocation system for pediatric heart transplantation.

Cardiac resynchronization therapy (and multisite pacing) in pediatrics and congenital heart disease: five years experience in a single institution.

Introduction: Clinical evidence supports the use of cardiac resynchronization therapy (CRT) in adults with heart failure, but experience in pediatrics and congenital heart disease (CHD) is limited in terms of patient numbers and follow‐up. We sought to determine the functional assessment and clinical outcomes in pediatric and CHD CRT patients followed uniformly at one institution.

Bridging children of all sizes to cardiac transplantation: The initial multicenter North American experience with the Berlin Heart EXCOR ventricular assist device

BACKGROUND Beginning in 2000 and accelerating in 2004, the Berlin Heart EXCOR (Berlin Heart Inc Woodlands, TX) became the first pediatric-specific ventricular assist device (VAD) applied throughout North America for children of all sizes. This retrospective study analyzed the initial Berlin Heart EXCOR pediatric experience as a bridge to transplantation. METHODS Between June 2000 and May 2007, 97 EXCOR VADs were implanted in North America at 29 different institutions. The analysis is limited to 73 patients (75%) from 17 institutions, for which retrospective data were available. RESULTS Median age and weight at VAD implant were 2.1 years (range, 12 days-17.8 years) and 11 kg (range, 3-87.6 kg), respectively. The primary diagnoses were dilated cardiomyopathy in 42 (58%), congenital heart disease in 19 (26%), myocarditis in 7 (10%), and other cardiomyopathies in 5 (7%). Pre-implant clinical condition was critical cardiogenic shock in 38 (52%), progressive decline in 33 (45%), or other in 2 (3%). Extracorporeal membrane oxygenation was used as a bridge to EXCOR in 22 patients (30%). Device selection was left VAD (LVAD) in 42 (57%) and biventricular assist devices (BiVAD) in 31 (43%). The EXCOR bridged 51 patients (70%) to transplant and 5 (7%) to recovery. Mortality on the EXCOR was 23% (n = 17) overall, including 35% (11 of 31) in BiVAD vs 14% (6 of 42) in LVAD patients (p = 0.003). Multivariate analysis showed younger age and BiVAD support were significant risk factors for death while on the EXCOR. CONCLUSIONS This limited but large preliminary North American experience with the Berlin Heart EXCOR VAD as a bridge to cardiac transplantation for children of all ages and sizes points to the feasibility of this approach. The prospective investigational device evaluation trial presently underway will further characterize the safety and efficacy of the EXCOR as a bridge to pediatric cardiac transplantation.

Rapid-Response Extracorporeal Membrane Oxygenation to Support Cardiopulmonary Resuscitation in Children With Cardiac Disease

Background— Survival of children with in-hospital cardiac arrest that does not respond to conventional cardiopulmonary resuscitation (CPR) is poor. We report on survival and early neurological outcomes of children with heart disease supported with rapid-response extracorporeal membrane oxygenation (ECMO) to aid cardiopulmonary resuscitation (ECPR). Methods and Results— Children with heart disease supported with ECPR were identified from our ECMO database. Demographic, CPR, and ECMO details associated with mortality were evaluated using multivariable logistic regression. Pediatric overall performance category and pediatric cerebral performance category scores were assigned to ECPR survivors to assess neurological outcomes. There were 180 ECPR runs in 172 patients. Eighty-eight patients (51%) survived to discharge. Survival in patients who underwent ECPR after cardiac surgery (54%) did not differ from nonsurgical patients (46%). Survival did not vary by cardiac diagnosis and CPR duration did not differ between survivors and nonsurvivors. Factors associated with mortality included noncardiac structural or chromosomal abnormalities (OR, 3.2; 95% CI, 1.3–7.9), use of blood-primed ECMO circuit (OR, 7.1; 95% CI, 1.4–36), and arterial pH <7.00 after ECMO deployment (OR, 6.0; 95% CI, 2.1–17.4). Development of end-organ injury on ECMO and longer ECMO duration were associated with increased mortality. Of pediatric overall performance category/pediatric cerebral performance category scores assigned to survivors, 75% had scores ≤2, indicating no to mild neurological injury. Conclusions— ECPR may promote survival in children with cardiac disease experiencing cardiac arrest unresponsive to conventional CPR with favorable early neurological outcomes. CPR duration was not associated with mortality, whereas patients with metabolic acidosis and noncardiac structural or chromosomal anomalies had higher mortality.

Extracorporeal Membrane Oxygenation for Bridge to Heart Transplantation Among Children in the United States Analysis of Data From the Organ Procurement and Transplant Network and Extracorporeal Life Support Organization Registry

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.

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.

The use of the Berlin heart EXCOR in patients with functional single ventricle

INTRODUCTION The frequency and successful use of pediatric ventricular assist devices (VADs) as a bridge to cardiac transplantation have been steadily increasing since 2003, but the experience in patients with complex congenital heart disease has not been well described. Using a large prospectively collected dataset of children supported with the Berlin Heart EXCOR VAD, we have reviewed the experience in children with single ventricular anatomy or physiology (SV), and compared the results with those supported with biventricular circulation (BV) over the same time period. METHODS The EXCOR Investigational Device Exemption study database was retrospectively reviewed. VAD implants under the primary cohort and compassionate use cohort between May 2007 and December 2011 were included in this review. RESULTS Twenty-six of 281 patients supported with a VAD were SV. The most common diagnosis was hypoplastic left heart syndrome (15 of 26). Nine patients were supported after neonatal palliative surgery (Blalock-Taussig shunt or Sano), 12 after a superior cavopulmonary connection (SCPC), and 5 after total cavopulmonary connection (TCPC). Two patients received biventricular assist devices, 1 after stage I surgery and 1 after stage II. SV patients were supported for a median time of 10.5 days (range, 1-363 days) versus 39 days (range, 0-435 days) for BV (P = .01). The ability to be bridged to transplant or recovery in SV patients is lower than for BV patients (11 of 26 [42.3%] vs 185 of 255 [72.5%]; P = .001). Three of 5 patients with TCPC were successfully bridged to transplant and were supported with 1 VAD. Seven of 12 patients with SCPC were bridged to transplant, and only 1 of 9 patients supported after a stage I procedure survived. CONCLUSIONS The EXCOR Pediatric VAD can provide a bridge to transplant for children with SV anatomy or physiology, albeit less successfully than in children with BV. In this small series, results are better in patients with SCPC and TCPC. VAD support for patients with shunted sources of pulmonary blood flow should be applied with caution.

Video-Assisted Thoracoscopic Cardiac Denervation: A Potential Novel Therapeutic Option for Children With Intractable Ventricular Arrhythmias

BACKGROUND Left cardiac sympathetic denervation is one of the therapeutic modalities used in the management of patients with medically refractory long QT syndrome. Traditionally, a thoracotomy or cervical incision has been used as the standard surgical approach for performing left cardiac sympathetic denervation. Video-assisted thoracoscopic surgery allows a minimally invasive technique. There is only one published series on the use of video-assisted thoracoscopic surgery for left cardiac sympathetic denervation in patients with long QT syndrome. METHODS We performed a retrospective clinical review of pertinent medical records and report a series including 9 pediatric patients (4 long QT syndrome, 4 catecholaminergic polymorphic ventricular tachycardia, and 1 idiopathic ventricular tachycardia) who underwent a left cardiac sympathetic denervation by means of video-assisted thoracoscopic surgery. RESULTS There were no severe complications, and 6 of 7 symptomatic patients with available follow-up experienced marked improvement in the first month after sympathectomy. CONCLUSIONS This minimally invasive procedure provides a safe novel therapeutic option for children with drug-refractory catecholaminergic polymorphic ventricular tachycardia and other catecholamine-triggered arrhythmias.

Surgical outcome for patients with the mitral stenosis–aortic atresia variant of hypoplastic left heart syndrome

OBJECTIVE We sought to identify and characterize a subgroup of patients with hypoplastic left heart syndrome who might be at higher risk for stage I failure. METHODS From January 2001 through December 2006, all patients with hypoplastic left heart syndrome who underwent stage I palliation at Childrens Hospital Boston were retrospectively reviewed. The subgroup with the mitral stenosis-aortic atresia variant was studied separately. We evaluated preoperative echocardiographic data, operative characteristics, and postoperative factors associated with death or the need for transplantation. The Kaplan-Meier method was used to assess survival. RESULTS Thirty-eight (23%) of 165 patients had mitral stenosis-aortic atresia. Hospital mortality or need for transplantation for patients with mitral stenosis-aortic atresia was significantly higher than for other anatomic subgroups (29% vs 7.9%, P = .002). Left ventricle-subepicardial coronary artery communications were present in 20 (53%) patients with mitral stenosis-aortic atresia and were associated with a significantly higher hospital mortality (50% vs 6%, P = .004). No difference in outcome was demonstrated between different sources of pulmonary blood flow. A longer cardiopulmonary bypass time (P = .02) and the need for postoperative extracorporeal membrane oxygenation support (P < .001) were associated with a higher mortality rate. CONCLUSIONS With improved outcomes in the management of neonates with hypoplastic left heart syndrome, those with the mitral stenosis-aortic atresia variant and left ventricle-subepicardial coronary artery fistulae have emerged as a higher-risk subgroup for failure of stage I palliation. Further investigation is required, and a change in clinical management strategy for this particular subgroup might be warranted.

System survival of nontransvenous implantable cardioverter-defibrillators compared to transvenous implantable cardioverter-defibrillators in pediatric and congenital heart disease patients

BACKGROUND Nontransvenous (NTV) implantable cardioverter-defibrillator (ICD) systems with pericardial and/or subcutaneous coils are used in select pediatric and congenital heart disease patients who are not candidates for transvenous ICD leads. Outcomes with these hybrid configurations are not well understood. OBJECTIVE The purpose of this study was to compare survival of NTV ICD systems to standard transvenous (TV) ICD systems. METHODS We conducted a retrospective single-center study in which the TV group was matched to the NTV group 2:1 by type of cardiac disease and implant date. RESULTS There were 39 patients in the NTV group and 78 matched in the TV group. Compared to the TV group, the NTV group was younger (median 7 vs 20 years) with a smaller body surface area at implant (0.9 vs 1.8 m(2); both P <.001). Median follow-up in the NTV group was 17 months. System survival at 12, 24, and 36 months was 73%, 55%, and 49% in the NTV group versus 91%, 83%, and 76% in the TV group (P = .003). A multivariable Cox proportional hazards model including group, body surface area, and age at implant revealed the NTV group to be an independent predictor of system failure (hazard ratio 2.9, P = .04). Rate of total unanticipated interventions in the NTV group was 18 versus 6 per 1,000 person-months in the TV group. In patients with NTV systems, 23% received appropriate shocks and 18% received inappropriate shocks. CONCLUSION Survival of ICD systems using NTV defibrillation coils is significantly shorter than with TV ICD systems. Although NTV systems provide protection for this unique subset of patients, more durable options are needed.