INTERMEDIATE FOLLOW-UP OF PEDIATRIC HEART-TRANSPLANT RECIPIENTS WITH ELEVATED PULMONARY VASCULAR-RESISTANCE INDEX

Objectives. This study examined perioperative and intermediate outcome s in pediatric cardiac transplant recipients who had elevated pulmonar y vascular resistance indexes preoperatively. Background. Elevated pul monary vascular resistance was associated with poor outcome in previou s studies and constitutes a relative contraindication to transplantati on. Few studies have evaluated this poor outcome risk factor in pediat ric patients. Methods. To evaluate outcomes of nonneonatal transplant recipients, records were reviewed and divided into Group I (preoperati ve pulmonary vascular resistance index greater than or equal to 6 unit s.m(2)) and Group II (pulmonary vascular resistance index <6 units.m(2 )). Donor/recipient weight ratios, ischemic times, length of intensive care unit stay, posttransplantation infection rates, arrhythmia, resp onse to pretransplantation vasodilator infusions and pulmonary vascula r resistance indexes at the first and most recent posttransplantation biopsies were analyzed. Results. Group I (8 patients) had a mean (+/-S EM) pulmonary vascular resistance index of 11.5 +/- 3.5 units m(2); Gr oup II (29 patients) had a mean pulmonary vascular resistance index of 2.3 +/- 0.4 units m(2) (p < 0.002). Pulmonary vascular resistance ind ex decreased from 12.3 +/- 3.9 to 3.9 +/- 0.9 units.m(2) (p < 0.05) in 7 Group I patients undergoing vasodilator infusion during pretranspla ntation catheterization. Thirty-six orthotopic heart transplantations were performed and one heterotopic transplantation. Donor weights exce eded recipient weights by 13% and 31% for Groups I and II, respectivel y (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 Gro up I and 15.1 days in Group II (p = 0.20). Infection rate was 38% in b oth groups (p > 0.80). Arrhythmias occurred in 90% of Group I and 42% of Group II (p < 0.03) patients. Pulmonary resistance index in Group I decreased from 11.5 +/- 3.5 to 3.3 +/- 1.2 units.m(2) (p < 0.03) by t he 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). Conclusi ons. 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. Pulm onary resistance index normalized early after transplantation. Pulmona ry vascular reactivity may be more important for survival than absolut e resistance index.