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

Reintervention for Superior Vena Cava Obstruction After Heart Transplant

BACKGROUND

Children undergoing orthotopic heart transplant (OHT) may require complex reconstruction of superior vena cava (SVC) anomalies. SVC anatomy and mode of reconstruction are potential risk factors for SVC obstruction.

METHODS

A retrospective single-center review was conducted of patients undergoing initial OHT between January 1, 1990, and July 1, 2021. Simple SVC anatomy included a single right SVC to the right atrium or bilateral SVCs with a left SVC to an intact coronary sinus, without prior superior cavopulmonary connection. Presence of anomalous SVC anatomy, superior cavopulmonary connection, or previous atrial switch operation defined complex anatomy. Reconstructive strategies included atrial anastomosis; direct SVC-to-SVC anastomosis; and augmented SVC anastomosis using innominate vein, patch, cavopulmonary connection, or interposition graft. The primary outcome was reintervention for SVC obstruction.

RESULTS

Of 288 patients, pretransplant diagnoses included congenital heart disease (n = 155 [54%]), cardiomyopathy (n = 125 [43%]), and other (n = 8 [3%]). Most (n = 208 [72%]) had simple SVC anatomy compared with complex SVC anatomy (80 [28%]). Reintervention for SVC obstruction occurred in 15 of 80 (19%) with complex anatomy and 1 of 208 (0.5%) with simple anatomy (P = .0001). Reintervention was more common when innominate vein or a patch was used (9/25 [36%]) compared with an interposition graft (1/7 [14%]) or direct anastomosis (6/82 [7%]; χ2 = 13.1; P = .001). Most reinterventions occurred within 30 days of OHT (14/16 [88%]).

CONCLUSIONS

Patients with complex SVC anatomy have a higher rate of reintervention for SVC obstruction after OHT compared with those with simple SVC anatomy. In cases of complex SVC anatomy, interposition grafts may be associated with less reintervention compared with complex reconstructions using donor tissue.

Extracorporeal Membrane Oxygenation Support After Heart Transplantation in Children-Outcomes of a Single Center Cohort

OBJECTIVES

Extracorporeal membrane oxygenation is used for postcardiotomy low cardiac output but is less established following heart transplantation. We characterized outcomes for children supported with extracorporeal membrane oxygenation after heart transplantation.

DESIGN

Single-center retrospective study.

SETTING

Large pediatric cardiac referral center.

PATIENTS

All patients who received heart transplantation and were cannulated to extracorporeal membrane oxygenation between 1995 and 2016.

INTERVENTIONS

Primary outcome measure was mortality 12 months postextracorporeal membrane oxygenation. Patient characteristics were analyzed for association with outcome according to early graft failure (extracorporeal membrane oxygenation ≤ 7 d after heart transplantation), or late graft failure.

MEASUREMENTS AND MAIN RESULTS

There were 246 heart transplants during the study period and 50 extracorporeal membrane oxygenation runs in 44 patients. Median time from transplant to extracorporeal membrane oxygenation was 1 day (range, 0-11.7 yr), with early graft failure in 28 patients (median 1, range 0-2 d) and 22 extracorporeal membrane oxygenation runs in 20 late graft failure patients (median, 0.8 yr; range, 8 d to 11.7 yr), including four patients with prior extracorporeal membrane oxygenation for early graft failure. Twenty-six patients (59%) survived to hospital discharge, and survival 12 months postextracorporeal membrane oxygenation was 24 patients (55%), lower in those with late graft failure (40% vs 67%; p 0.02). Independent risk factors for 12-month mortality were congenital heart disease, higher pulmonary vascular resistance indexed to body surface area (> 2.2 Woods U/m), and higher creatinine. Higher panel reactive antibody levels were associated with 12-month mortality in the late graft failure group only.

CONCLUSIONS

Extracorporeal membrane oxygenation can be effectively used to rescue patients with graft dysfunction after heart transplantation but is associated with high early mortality. Factors associated with mortality within 12 months include presence of congenital heart disease, renal dysfunction, elevated pulmonary vascular resistance indexed to body surface area and in those supported with extracorporeal membrane oxygenation late after heart transplantation, significant human leukocyte antigen sensitization.

Late primary transplantation in complex congenital heart disease

Heart transplantation is a viable option for patients with congenital heart disease who manifest heart failure, predominantly post-surgical palliation. We present a case of complex congenital heart disease, where surgical palliation was considered not to be an option. Considerate medical management with close follow-up allowed for a nine-yr delay until eventual successful heart transplantation. The case also highlights the natural history over nine yr of the effects of right ventricular outflow tract obstruction on the left ventricular remodeling which is analogous to a PA banding in patients with dilated cardiomyopathy.

Current challenges in pediatric heart transplantation for congenital heart disease

PURPOSE OF REVIEW

Pediatric heart transplantation is an established therapy for end-stage cardiac disease without suitable medical or surgical options. However, transplantation for congenital heart disease carries an incremental risk that challenges the pediatric transplant team on multiple levels.

RECENT FINDINGS

With improved outcomes following palliative and corrective congenital cardiac surgery, cardiac transplantation has decreased in recent years as a primary therapy. Nevertheless, congenital heart disease remains the most common indication for cardiac transplantation during infancy. Primary transplantation in infancy is selectively recommended for severe systemic ventricular dysfunction, severe atrioventricular valve insufficiency, and occlusive coronary artery anomalies, particularly with single ventricle physiology. Wait-list mortality remains highest for infants with prior palliative surgery and patients with failing Fontan physiology, both of whom have limited options for effective mechanical circulatory support. The sensitized patient carries an increased risk with prolonged wait times, although virtual cross-matches and single bead assays for donor-specific antigens have facilitated the transplant process. Early and late survival after transplantation for congenital heart disease remain inferior to cardiomyopathy, with prior Fontan procedure as a major risk factor. However, among survivors at 6 months, late outcomes are generally excellent. Major late causes of death include allograft vasculopathy, post-transplant lymphoproliferative disease, and acute rejection. Noncompliance with medications remains a major risk for teenage mortality.

SUMMARY

Despite the myriad of evolving challenges, pediatric heart transplantation for congenital heart disease enjoys routine short and long-term success at experienced centers for the vast majority of such patients without other options.

Pediatric heart transplantation for congenital and restrictive cardiomyopathy

BACKGROUND

Recent reports suggest worse outcomes in pediatric orthotopic heart transplantation (OHT) for congenital heart disease (CHD) and restrictive cardiomyopathy (RCM). We examined early outcomes in these diverse groups of patients in comparison with patients with dilatated cardiomyopathy (DCM).

METHODS

From 2000 to 2011, 209 patients were included: 50 with CHD, 23 with RCM, and 136 with DCM. Early survival was studied, as was the occurrence of acute rejection, donor-specific antibodies (DSAs) and nondonor-specific antibodies (NSDAs), incidence of pulmonary hypertension (PHT), right ventricular failure (RVF), and the need for mechanical circulatory support (MCS).

RESULTS

The incidence of preoperative PHT was greatest in the RCM group (χ(2)p = 0.0006); the requirement for mechanical support before OHT was greatest in patients with DCM. Thirty-day survival was 92.0%, 97.1%, and 100% for patients with CHD, DCM, and RCM respectively. The incidence of RVF was highest for patients with RCM (43.5%; versus CHD, 26.0%; versus DCM, 14.7%). One-year survival estimates for patients with CHD, DCM, and RCM were 92.0%, 97.8%, and 82.6%, respectively (log-rank p = 0.165). Multivariable analysis revealed 4 significant risk factors for mortality: age, incidence of acute rejection, preoperative PHT, and the presence of NDSAs. The occurrence of DSAs was similar, although there was a significantly higher incidence of NDSAs in the CHD and RCM groups (36.0% and 30.4%, respectively, versus 14.0% in the DCM group; χ(2)p = 0.0024).

CONCLUSIONS

Equivalent outcomes are achievable in pediatric OHT despite marked heterogeneity in anatomic and physiologic complexity in recipients. Physiologic factors such as PHT are likely to be more important than anatomic complexities in determining survival. The potential relevance of NDSAs warrants further investigation.