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Intermediate follow-up of pediatric heart transplant recipients with elevated pulmonary vascular resistance index
R J Gajarski1, J A Towbin, J T Bricker
1Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston 77030.
Insights
Pediatric heart transplant recipients with elevated pulmonary vascular resistance (PVR) showed similar outcomes to those with normal PVR, with PVR normalizing post-transplant. Pulmonary vascular reactivity, not absolute PVR, may be key for survival.
Area of Science:
- Pediatric Cardiology
- Transplantation Medicine
- Pulmonary Hypertension
Background:
- Elevated pulmonary vascular resistance (PVR) is a known risk factor for poor outcomes in heart transplantation.
- Previous studies have linked high PVR to adverse events, yet limited data exists for pediatric populations.
- PVR is often considered a relative contraindication for cardiac transplantation.
Purpose of the Study:
- To evaluate perioperative and intermediate outcomes in pediatric cardiac transplant recipients with preoperatively elevated PVR.
- To compare outcomes between pediatric patients with elevated PVR (Group I) and normal PVR (Group II).
- To assess the impact of PVR on post-transplant recovery and survival.
Main Methods:
- Retrospective review of non-neonatal pediatric cardiac transplant recipients.
- Division into Group I (preoperative PVR index ≥ 6 units·m²) and Group II (PVR index < 6 units·m²).
- Analysis of donor/recipient factors, ischemic times, ICU stay, infection rates, arrhythmias, and PVR changes post-transplant.
Main Results:
- Group I (n=8) had a mean PVR index of 11.5 units·m², significantly higher than Group II (n=29, 2.3 units·m²).
- Arrhythmias were more frequent in Group I (90%) compared to Group II (42%).
- PVR normalized early post-transplant in Group I (from 11.5 to 3.3 units·m²), with similar mortality rates (25% vs. 21%) between groups.
Conclusions:
- Pediatric cardiac transplant recipients with elevated PVR did not experience significantly longer ICU stays or higher infection rates.
- Arrhythmias were more common in the elevated PVR group, but PVR normalized post-transplantation.
- Pulmonary vascular reactivity may be a more critical determinant of survival than the absolute preoperative PVR 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.