NM-250
The Earlier, The Better: The Role of ABO-Incompatible Heart Transplantation in the Treatment of Newborn Complex Congenital Heart Disease
Patel J, Hsieh H, Kahana M
Albert Einstein-Montefiore Medical Center, Bronx, NY, USA
With advances in neonatal cardiac surgical repairs and palliative procedures, the use of heart transplantation for treatment of congenital heart defects (CHD) in the newborn period is uncommon. Few CHD are considered to be incompatible with surgical repair or palliation. Examples include pulmonary atresia with intact ventricular septum and right ventricular-dependent coronary circulation (PA/IVS, RVDCC), transposition of the great arteries with single ventricle and heart block, complex heterotaxy syndromes, severe atrioventricular canal or valve defects, and in some centers, hypoplastic left heart syndrome. Graft survival in newborn heart transplant recipients is approximately 59% at age 25.
We describe a case of ABO incompatible transplant in a newborn with PA/IVS, RVDCC. PA/IVS comprises only approximately 1 – 1.5% of all CHD and 50% of these may have RV sinusoids with concomitant coronary artery to RV fistulas. A small subset of patients has RVDCC where there is no anterograde aortocoronary flow and desaturated blood from the RV supplies the myocardium causing catastrophic ischemia. Clinical management of these patients can be difficult, and due to their high early mortality rate after single ventricle palliative surgery, it is recommended they proceed directly to heart transplantation.
Our patient is an ex-38.4 week male who became dusky with SpO2 80% unresponsive to supplemental oxygen. TTE showed PA/IVS, PFO with R to L flow, a hypertrophied and hypoplastic RV with moderate dysfunction and a hypoplastic TV. RV coronary sinusoids were seen with severely dilated left main and LAD and fistulous connection to the RV outflow. Cardiac cath showed suprasystemic RV pressures and RVDCC. The RCA was atretic with filling only from the RV, and there was a large coronary fistula between the LCA and RVOT. The LV did not have robust coronary circulation, likely due to steal from the fistula. ECMO in this case was contraindicated due to obligatory ductal shunting and coronary steal and the patient was immediately listed for heart transplant.
The patient underwent ABO-incompatible bi-atrial orthotopic heart transplant on DOL 12. Cardiopulmonary bypass was complicated by the need for an exchange transfusion prior to bypass to achieve IgM Anti A antibodies less than 1:4. This exchange was repeated before releasing the aortic crossclamp. The patient was transported to PICU paced at 140, on vasopressor infusions. He is currently 3 months post-transplant, feeding and growing well.
Due to limited availability of donor organs, the transplantation of ABO incompatible hearts has become an acceptable approach in infants until age 15 months. There is similar early survival for ABO incompatible transplants as in ABO compatible because these infants fail to produce sufficient isohemagglutinins to mount hyperacute rejection. This increases organ availability in young patients and allows for use of organs with uncommon blood types.
In summary, heart transplant, particularly ABO incompatible heart transplant, poses unique challenges but may be the only chance of survival for the neonate with CHD without a repair or palliation option.
Chinnock RE et al. Heart transplantation for CHD in the First Year of Life. CurrCardiol Rev. 2011;7(2):72-84.
Top
