Background: Because of the poor prognosis of pediatric restrictive cardiomyopathy, transplantation has been proposed as the treatment of choice for this disease.
Methods: We reviewed our experience with the presentation, evaluation, and short-term outcome in 8 pediatric patients with restrictive cardiomyopathy referred for transplantation. Potential reversibility of elevation in pulmonary vascular resistance was tested before transplantation with nitroprusside and nitric oxide, with follow-up cardiac catheterization performed 6 to 12 months after transplantation.
Results: The mean age of diagnosis of restrictive cardiomyopathy was 6.3 years and the mean interval from diagnosis to referral for transplantation was 3.6 years. Elevation of pulmonary vascular resistance was common and tended to progress with longer follow-up. Three of the 8 patients had pulmonary vascular resistance indices greater than 10 Woods unit/m(2) and transpulmonary gradients greater than 20 mm Hg. The administration of nitroprusside and nitric oxide reversed elevated pulmonary resistance and transpulmonary gradients in all patients. Nitric oxide successfully reversed pulmonary vascular resistance in patients unresponsive to nitroprusside. All patients underwent successful transplantation and follow-up catheterization revealed normal pulmonary hemodynamics in each patient.
Conclusions: Pediatric restrictive cardiomyopathy can be associated with marked elevation in the pulmonary vascular resistance, which may contribute to the poor prognosis in these patients and potentially make cardiac transplantation problematic. Orthotopic cardiac transplantation can be successfully performed in patients who demonstrate reversibility of pulmonary vascular resistance. Nitric oxide appears to be the best agent to demonstrate reversibility of pulmonary resistance in these patients.