Heart-kidney combined transplant in a pediatric patient at Mayo Clinic

The first pediatric heart transplant at Mayo Clinic was performed in 1991. More than 400 heart transplants have been performed at Mayo Clinic in Rochester, Minn.; of these, more than 40 have been in pediatric patients (younger than 18 years), and 30 more have been performed in adult patients with congenital heart disease.

Mayo Clinic pediatric patient survival after transplant exceeds the United Network for Organ Sharing and Scientific Registry of Transplant Recipients expected average survival at both one month and one year. One-year survival for patients who received transplants at Mayo Clinic since 2009 is 100 percent. Multiorgan transplants in adult patients with congenital heart disease, including heart-kidney, heart-liver and heart-lung combined transplants, have been performed with excellent success at Mayo Clinic.

A case of multiorgan transplant

The first pediatric combined heart-kidney transplant at Mayo Clinic was performed earlier this year (2012) in a 14-year-old boy. After diagnosis of restrictive cardiomyopathy, he had undergone an isolated heart transplant in 2002. He did very well initially after the transplant, even playing on his school basketball team. However, in the fall of 2011, he began to have episodes of lightheadedness and fainting while running down the basketball court. A treadmill exercise stress test was able to reproduce his symptoms of dizziness at maximal exercise, with concurrent ST segment elevation.

Coronary angiography was performed and demonstrated severe coronary vasculopathy. His left anterior descending coronary artery (LAD) was 90 percent obstructed by a single discrete lesion. The left main coronary artery and left circumflex coronary artery showed 30 percent lesions. His right coronary artery was 50 percent obstructed in several locations. Additionally, diffuse atherosclerotic disease was seen distally.

A drug-eluting stent was placed successfully across the area of stenosis in the LAD. An implantable cardioverter-defibrillator was also placed because of his potential for ischemia-induced arrhythmia. His renal function was abnormal but not yet to the point of needing consideration for kidney transplant. The patient was able to return home and resume normal activities. However, because of the current understanding of the natural history of patients with severe coronary lesions after transplant, the patient was listed for a second heart transplant.

Three months after his initial stent placement, he returned for repeat coronary angiography. This angiogram revealed a new site of discrete stenosis just distal to the previous stent placement, despite treatment with aspirin, clopidogrel and pravastatin. The stent itself also had evidence of in-stent stenosis. The patient underwent repeat stenting of the narrowed area, again with an excellent result.

During these follow-up evaluations, it was noted that his renal dysfunction had worsened. He was seen by Mayo Clinic pediatric nephrology transplant colleagues; his chronic kidney disease was secondary to his nine years of exposure to calcineurin-inhibiting medications to prevent rejection of his initial heart allograft. The decision was made to list him for combined heart-kidney transplant on the basis of his impaired renal function and severe recurrent cardiac allograft vasculopathy.

Three weeks after he was listed for the combined transplant, a donor became available, and he successfully underwent a combined heart-kidney transplant. His postoperative course was without complications, and he was discharged after only seven days in the hospital. He has had no evidence of rejection of either organ four months after transplant. The transplant team has devised a long-term plan for the patient that will include the use of mTOR-inhibiting medications, such as sirolimus, to reduce the risk of recurrent coronary vasculopathy in the new heart and the amount of nephrotoxic medication required for antirejection therapy.

Points to remember

This patient exemplifies the increasing complexity of patients considered for organ transplants. As more pediatric patients are undergoing cardiac transplant, the number of individuals who outlive their transplant is increasing. Furthermore, a notable segment of these pediatric patients have comorbid conditions that contribute to additional system failure. In this patient, renal failure developed as a result of drugs required to control rejection of his original heart transplant.

These complex patients are well served by the multidisciplinary approach employed in the Mayo Clinic model of care. In this patient, pediatric cardiologists, adult cardiologists, pediatric nephrologists and transplant surgeons worked together to provide the best care possible for the patient. And the patient has already started asking when he can play basketball again.