Intermediate follow-up of pediatric heart transplant recipients with elevated pulmonary vascular resistance index.

OBJECTIVES: This study examined perioperative and intermediate outcomes in pediatric cardiac transplant recipients who had elevated pulmonary vascular resistance indexes preoperatively.
BACKGROUND: Elevated pulmonary vascular resistance was associated with poor outcome in previous studies and constitutes a relative contraindication to transplantation. Few studies have evaluated this poor outcome risk factor in pediatric patients.
METHODS: To evaluate outcomes of nonneonatal transplant recipients, records were reviewed and divided into Group I (preoperative pulmonary vascular resistance index > or = 6 units.m2) and Group II (pulmonary vascular resistance index < 6 units.m2). Donor/recipient weight ratios, ischemic times, length of intensive care unit stay, posttransplantation infection rates, arrhythmia, response to pretransplantation vasodilator infusions and pulmonary vascular resistance indexes at the first and most recent posttransplantation biopsies were analyzed.
RESULTS: Group I (8 patients) had a mean (+/- SEM) pulmonary vascular resistance index of 11.5 +/- 3.5 units,m2; Group II (29 patients) had a mean pulmonary vascular resistance index of 2.3 +/- 0.4 units,m2 (p < 0.002). Pulmonary vascular resistance index decreased from 12.3 +/- 3.9 to 3.9 +/- 0.9 units.m2 (p < 0.05) in 7 Group I patients undergoing vasodilator infusion during pretransplantation catheterization. Thirty-six orthotopic heart transplantations were performed and one heterotopic transplantation. Donor weights exceeded recipient weights by 13% and 31% for Groups I and II, respectively (p > 0.25). Donor ischemic time was 215 min for Group I and 225 min for Group II (p > 0.75). Intensive care unit stay was 11.5 days in Group I and 15.1 days in Group II (p = 0.20). Infection rate was 38% in both groups (p > 0.80). Arrhythmias occurred in 90% of Group I and 42% in Group II (p < 0.03) patients. Pulmonary resistance index in Group I decreased from 11.5 +/- 3.5 to 3.3 +/- 1.2 units.m2 (p < 0.03) by the first posttransplantation biopsy and have not changed subsequently. During 2.3 years (range 0.3 to 8.5) of follow-up, the mortality rate was 25% and 21% for Groups I and II, respectively (p > 0.80).
CONCLUSIONS: Group I patients did not require significantly oversized donors, restricted donor locations or longer intensive care unit stays or have higher infection rates; however, arrhythmias were more frequent. Pulmonary resistance index normalized early after transplantation. Pulmonary vascular reactivity may be more important for survival than absolute resistance index.