The state of pediatric heart transplantation

Decline in renal function following thoracic organ transplantation in children

Heart and/or lung transplantation are life-saving treatments for end-stage cardiopulmonary disease; however, chronic renal failure may develop. The impact of thoracic organ transplant on renal function in infants and children is not well characterized. This retrospective cohort study evaluated renal function following thoracic organ transplantation in 46 children (32 heart, 9 lung, 5 heart-lung; median age 4.1 years) with at least 12 months of follow-up. Glomerular filtration rate (GFR, ml/min/1.73 m2) was estimated by the Schwartz formula throughout and each GFR estimate was converted to per cent normal for age (GFR%). Changes in renal function following transplantation were analyzed using longitudinal mixed-effects linear regression models. GFR% decreased following thoracic organ transplantation (p <0.001). Younger age at transplant was associated with a greater decline in GFR% (p <0.01). The decline in GFR% persisted after adjustment for nutritional status with body mass index or weight-for-length z-scores. The prevalence of renal insufficiency (GFR% <75) increased from 22% at transplant to 55% and 85% at 1 and 5 years post transplant, respectively, while 15% had a GFR% <50 at 5 years post transplantation. Higher tacrolimus trough levels over the first 6 months correlated with a lower GFR% (p <0.01). Renal function declined significantly following thoracic organ transplantation.

Use of assist devices and ECMO to bridge pediatric patients with cardiomyopathy to transplantation

BACKGROUND

Pulsatile ventricular assist devices (VADs) are used to bridge adults with end-stage heart disease to transplantation. A combination of external implantable pulsatile and continuous-flow external mechanical support now can be used to bridge pediatric patients with end-stage cardiomyopathy to orthotopic heart transplantation (OHT).

METHODS

We reviewed consecutive pediatric patients with cardiomyopathy (n = 28) who required mechanical cardiac support from July 1995 to February 2001. All were OHT candidates with severe hemodynamic compromise despite maximal medical support. We excluded from this series patients who had undergone cardiotomy.

RESULTS

Nineteen patients received support from external continuous-flow devices, either with extracorporeal membrane oxygenation or with centrifugal VADs, and 9 patients received pulsatile support. Nineteen of 28 (68%) patients were successfully bridged to transplant (17) or weaned (2) from their devices after recovery. Of the patients successfully bridged to transplant or recovery, 89% are alive to date. Univariate analysis revealed that a lower bilirubin concentration after 2 days of support was associated with a favorable outcome (p = 0.006). As expected, the patients with pulsatile VADs had significantly higher rates of extubation and oral feeding.

CONCLUSION

Pulsatile and continuous-flow devices can complement each other to significantly extend the lives of a wide range of pediatric patients with severe cardiomyopathies.