PHARMACOLOGICAL REDUCTION OF PRETRANSPLANTATION PULMONARY VASCULAR-RESISTANCE PREDICTS OUTCOME AFTER PEDIATRIC HEART-TRANSPLANTATION

Pulmonary hypertension leading to donor right ventricular dysfunction remains a major risk factor associated with poor outcome after heart t ransplantation. This study evaluated a pretransplantation protocol to assess pulmonary vascular resistance index and its response to pharmac ologic modulation. Cardiac catheterization was performed in 25 patient s (mean age, 8.6 years [range, 1 to 17 years]; mean weight, 27.3 kg [r ange, 8.1 to 54 kg]) with end-stage heart failure. Mean pulmonary arte ry and capillary wedge pressures and cardiac index were measured in th e baseline state and during administration of 100% oxygen, dobutamine at 10 mug/kg/min, and nitroprusside at 1 to 4 mug/kg/min. Transpulmona ry pressure gradient and pulmonary vascular resistance index were calc ulated. In 22 survivors, hemodynamics were reassessed 1 and 4 weeks af ter transplantation. The mean cardiac index significantly increased (2 .2 to 3.2 L/min/m2); transpulmonary pressure gradient (12.7 to 9.6 mm Hg) and pulmonary vascular resistance index (6.2 to 3.0 units/m2) decr eased during the drug study. In 12 patients with a baseline pulmonary vascular resistance index of more than 6 units/m2, 10 survived heart t ransplantation. This study shows that pharmacologic reduction of the p ulmonary vascular resistance index in the pretransplantation protocol predicts reduced pulmonary vascular resistance index and a favorable o utcome after heart transplantation.