Autologous cellular cardiomyoplasty for pediatric dilated cardiomyopathy patients: New therapeutic option for children with failing heart?

Dilated cardiomyopathy (DCM) is the most common form of cardiomyopathy in children (1). The causes of DCM vary and the most common causes are genetic defects (familial DCM or sporadic genetic defects) or associated with neuromuscular disorders, such as muscular dystrophy. Other causes are secondary to the myocarditis; exposure to toxins or anti-cancer drugs such as anthracyclines, immune system diseases, malnutrition, or unknown (idiopathic). Despite various causes of DCM, the pathophysiological feature of the disease is characterized as loss of functioning cardiomyocyte by which the myocardium fails to maintain normal contractile function. DCM patients exhibit typical congestive heart failure symptoms that are limited daily activities, shortness of breath, sweating, peripheral coldness, edema, hepatomegaly, palpitation, and/or failure to thrive due to heart chamber dilatation, low cardiac output, and venous congestion (2). Although approximately 30% of DCM patients are able to recover from the heart failure, 60% of patients remain the same or worsen the heart failure over time (1). These patients require various medical treatments (1, 2). Harman et al. (3), however, have recently reported that the 40% of children with symptomatic DCM are resistant to medical treatment and the outcome of the patients with medical treatment does not improve in the previous several decades. For the patients with advanced heart failure, the heart transplantation is the only therapeutic option (3). The number of pediatric heart transplantation is 350–400 cases annually, which tends to reach a plateau for the past 10 yr (4). Although survival rate of post-transplanted pediatric patients has been dramatically improved in the past 10 yr, the average waiting time for heart transplantation becomes longer than adult cases due to limited availability of donor hearts. In addition, the heart transplant recipient requires life-long immunosuppression treatment to prevent graft rejection and the long-term survival rate over 10 yr remains to be improved considering their age at heart transplantation (3). Ventricular assist devices (VADs) for pediatric patients have been under development. Recent reports showed the quality of the devices (size, duration, and complication risks) has been improved; however, VADs support the failing heart temporally to bridge the patient toward heart transplantation (5–8). Thus, alternative therapeutic options have to be considered for DCM children with advanced heart failure. In the current issue of the Pediatric Transplantation, Olgunturk et al. report two pediatric cases with end-stage DCM who underwent peripheral stem cell transplantation via direct coronary artery injection. The results were striking in that both cases dramatically improved clinical symptoms, biochemical examination, and the cardiac function evaluated by transthoracic echocardiography. In particular, one case dramatically improved clinical symptoms from NYHA class IV to class I at six months after the stem cell transplantation and was successfully removed from the heart transplantation waiting list. Their report suggests that stem cell cardiomyoplasty could potentially be an alternative therapeutic option for children with end-stage DCM. Cellular cardiomyoplasty is considered as a new and promising therapeutic option for cardiac repair. Numerous studies in adult Pediatr Transplantation 2010: 14: 151–153 2010 John Wiley & Sons A/S.