F. Bennett Pearce

Prospective Trial of a Pediatric Ventricular Assist Device

BACKGROUND Options for mechanical circulatory support as a bridge to heart transplantation in children with severe heart failure are limited. METHODS We conducted a prospective, single-group trial of a ventricular assist device designed specifically for children as a bridge to heart transplantation. Patients 16 years of age or younger were divided into two cohorts according to body-surface area (cohort 1, <0.7 m(2); cohort 2, 0.7 to <1.5 m(2)), with 24 patients in each group. Survival in the two cohorts receiving mechanical support (with data censored at the time of transplantation or weaning from the device owing to recovery) was compared with survival in two propensity-score-matched historical control groups (one for each cohort) undergoing extracorporeal membrane oxygenation (ECMO). RESULTS For participants in cohort 1, the median survival time had not been reached at 174 days, whereas in the matched ECMO group, the median survival was 13 days (P<0.001 by the log-rank test). For participants in cohort 2 and the matched ECMO group, the median survival was 144 days and 10 days, respectively (P<0.001 by the log-rank test). Serious adverse events in cohort 1 and cohort 2 included major bleeding (in 42% and 50% of patients, respectively), infection (in 63% and 50%), and stroke (in 29% and 29%). CONCLUSIONS Our trial showed that survival rates were significantly higher with the ventricular assist device than with ECMO. Serious adverse events, including infection, stroke, and bleeding, occurred in a majority of study participants. (Funded by Berlin Heart and the Food and Drug Administration Office of Orphan Product Development; ClinicalTrials.gov number, NCT00583661.).

Outcomes of Pediatric Patients With Hypertrophic Cardiomyopathy Listed for Transplant

BACKGROUND The course of pediatric hypertrophic cardiomyopathy (HCM) is variable, and the indications for heart transplantation (HTx) are ill defined. This study investigated outcomes and risk factors for adverse outcomes after listing for HTx. METHODS A multicenter, event-driven data registry of patients aged < 18 years listed for HTx between January 1993 and December 2007 was used. RESULTS During the study period, 3,147 children were listed for HTx (mean age, 7.6 +/- 0.8 years). Of l,320 with CM at listing, 77 (6%) had HCM (61% boys; 79% white); 59% were United Network of Organ Sharing (UNOS) status I, 30% were receiving inotropes, 27% were ventilated, and 8% required extracorporeal membrane oxygenation. Arrhythmia had occurred in 27%, and 14% had failure to thrive. Within 1 year, 65% underwent HTx. Overall, 25 patients died after listing: 11 (14%) while waiting and 14 of 49 (29%) after HTx. Pre-HTx survival was lower for those listed at age < 1 year (p = 0.0005). Risk factors for death after listing included UNOS status 1 (p = 0.01) and younger age (relative risk, 2.3; p = 0.001). Late (10-year) survival after HTx for HCM patients was 47% vs 63% for non-CM patients within the database. CONCLUSIONS Children with HCM listed for HTx age < 1 year and UNOS status 1 have the highest mortality awaiting HTx. A more rigorous identification of additional risk factors should be performed to better define timing of listing and which patient sub-group may derive optimal benefit from HTx.

Comparison of risk factors and outcomes for pediatric patients listed for heart transplantation after bidirectional Glenn and after Fontan: an analysis from the Pediatric Heart Transplant Study.

BACKGROUND Patients listed for transplant after the bidirectional Glenn (BDG) may have better outcomes than patients listed after Fontan. This study examined and compared outcomes after listing for BDG and Fontan patients. METHODS All patients listed for transplant after the BDG in the Pediatric Heart Transplant Study between January 1993 and December 2008 were evaluated. Comparisons were made with Fontan patients and with a matched cohort of congenital heart disease patients. Competing outcomes analysis and actuarial survival were evaluated for the study populations, including an examination of various risk factors. RESULTS Competing outcomes analysis for BDG and Fontan patients after listing were similar. There was no difference in actuarial survival after listing or transplant among the 3 cohorts. Mechanical ventilation, United Network of Organ Sharing status, and age were risk factors for death after listing in BDG and Fontan patients, but ventilation at the time of transplant was significant only for the Fontan patients. Mortality was increased in Fontan patients listed < 6 months after surgery compared with patients listed > 6 months after surgery, but no difference was observed in BDG patients. There was a trend toward improved survival after listing for both populations across 3 eras of the study, but this did not reach statistical significance. CONCLUSION Outcomes after listing for BDG and Fontan patients are similar. Mechanical ventilation at the time of transplant remains a significant risk factor for death in the Fontan population, as does listing for transplant soon after the Fontan, suggesting that some patients may benefit from transplant instead of Fontan completion.

Etiology and retrieval of retained central venous catheter fragments within the heart and great vessels of infants and children

BACKGROUND The use of centrally positioned venous catheters plays an indispensable role in the care of infants and children. METHODS Since 1992 the authors have seen nine patients who experienced fragmentation and migration of catheter fragments into the central circulation. The patients ranged in age from 6 days to 15 years. RESULTS Sites of migration included pulmonary artery (five patients), superior vena cava (two patients), hepatic vein and innominate vein (one patient). The elapsed time from recognition of retained catheter fragments until retrieval ranged from a few hours to 6 weeks. CONCLUSION All retained fragments were successfully removed during cardiac catheterization without complications.

Successful cardiac transplant after Berlin Heart bridge in a single ventricle heart: Use of aortopulmonary shunt as a supplementary source of pulmonary blood flow

exchanged her paracorporeal Levitronix RVAD for a Thoratec intracorporeal VAD (Pleasanton, Calif). Postoperatively, she recovered from MSOF and was discharged from the hospital on postoperative day 53. Repeat RVAD turndown 4 months later showed functional RV recovery, and the patient’s Thoratec RVAD was successfully explanted. One month later, she was at home, doing well, and enjoying normal daily activities.

Mechanical circulatory support for myocarditis: How much recovery should occur before device removal?

A 12-year-old girl with presumed myocarditis was supported with right and left ventricular assist devices for 68 days before device removal. During this time, the patient underwent echocardiography and right heart catheterization for evaluation of cardiac recovery. This case report serves as the basis for a discussion of criteria for deciding when to terminate mechanical circulatory support in a patient with recovery after acute myocarditis.

Mechanical Circulatory Support: Strategies and Outcomes in Pediatric Congenital Heart Disease

Patients with acute or progressive heart failure in the setting of congenital heart disease may need mechanical circulatory support (MCS) to enhance survival while awaiting cardiac transplantation. Because the majority of MCS devices are implanted after prior cardiac operations, special precautions are necessary at the time of implant. MCS in single ventricle patients usually requires ventricular and aortic cannulation, with a systemic to pulmonary artery shunt for pulmonary blood flow. Limited outcomes data is available, with less than 15% of pediatric MCS patients having congenital heart disease. The Berlin EXCOR is the only durable device currently available for infants. Neurologic complications are the major cause of mortality, and survival during support is poor for infants <5 kg. Patients post-Fontan with acute cardiac failure and/or respiratory failure are at high risk for death before transplant and should be considered for MCS therapy. Several emerging miniature continuous flow devices will soon broaden the landscape of available pediatric devices.

Single-center experience with extracorporeal photopheresis in pediatric heart transplantation

BACKGROUND The pediatric heart transplant literature contains little information regarding extracorporeal photopheresis (ECP), despite International Society for Heart and Lung Transplantation guidelines recommending it for recurrent/recalcitrant rejection. We report our experience with ECP in pediatric heart transplantation. METHODS Data were obtained on heart transplant patients who were aged ≤ 18 years at the time of transplantation and received ECP between 1990 and 2012 at our institution. RESULTS Twenty heart transplant patients underwent 22 courses of ECP. Median ages were 12.7 years (range, 0.3-18.5 years) at transplant and 15.3 years (range, 7.3-31 years) at initial ECP. Median time from transplant to ECP was 1.4 years (range, 0.1-12.6 years). The median ECP duration was 5.8 months (range, 1.9-16.1 months). Indications for ECP included rejection with hemodynamic compromise (HC) in 4 patients, rejection without HC in 12, and prophylaxis in 2. Eleven patients died at a median time of 3.1 years after the start of ECP. Survival after ECP was 84% at 1 year and 53% at 3 years. Eleven patients were considered non-compliant and had a trend toward lower survival of 75% at 1 year and 18% at 3 years (p = 0.06 compared with compliant patients). One patient developed Pneumocystis carinii pneumonia during ECP and post-transplant lymphoproliferative disease 21 months after finishing ECP. No other adverse effects or infectious complications associated with ECP were noted. CONCLUSIONS This case series represents the largest reported experience with ECP in pediatric heart transplantation. ECP can be safely applied in this patient group. Despite EPC, non-compliant patients showed a trend toward lower survival than compliant patients.

Implantation of the HeartWare HVAD in a Child After a Recent Thromboembolic Stroke

We report the implantation of a HeartWare left ventricular assist device in a child. A 9-year-old girl presented in cardiogenic shock complicated by an embolic stroke. Catheter-based thrombolysis partially reversed the neurologic deficit, but worsening cardiac failure prompted consideration of mechanical circulatory support (MCS). Limited available pericardial space, anticoagulation requirements, and thromboembolic potential favored the use of the HeartWare left ventricular assist device (HeartWare International, Inc, Framingham, MA). After device implantation and intensive physical rehabilitation, the patient underwent successful cardiac transplantation after 60 days of support.

Cardiac transplantation and mechanical support for functional single ventricle.

Cardiac transplantation has played a pivotal role in the therapeutic algorithm for anatomically uncorrectable congenital heart disease, particularly the failing single ventricle. The historical evolution from Kantrowitz to Bailey and beyond challenges the application of this scarce resource to complex cardiac malformations in the presence of physiologic and circulatory failure. While selection of cardiac transplantation as primary therapy for hypoplastic-left heart syndrome is currently rare, the failing single ventricle in various stages of the Fontan pathway is increasingly considered for this therapy. The results of transplantation in this complex situation have progressively improved and now approached the late outcomes for other conditions. Mechanical circulatory support for the failing single ventricle has recently carried infants and children to successful transplant. The development of miniaturized continuous flow pumps offers the hope of major new avenues of successful circulatory support for single ventricle patients.