Low donor-to-recipient weight ratio does not negatively impact survival of pediatric heart transplant patients.
ABSTRACT A major limitation to success in pediatric heart transplantation is donor organ shortage. While the use of allografts from donors larger than the recipient is accepted, the use of undersized donor grafts is generally discouraged. Using the UNOS database, we wanted to evaluate whether using smaller donor hearts affects the short- and long-term survival of pediatric heart transplant patients. A retrospective analysis of data entered into the UNOS database from April 1994 to May 2008 was performed. Pediatric heart transplant recipients (ages 0-18 yr) with DRWR <2.0 were identified and divided into two groups: Low-DRWR (<0.8) and Ideal-DRWR (0.8-2.0). Patients' demographics, pretransplant diagnoses, age at transplantation, severity of pretransplant condition, and rate of complications prior to hospital discharge after transplantation were noted. Fisher's exact, chi-square, and Wilcoxon rank sum tests were used to compare patients' baseline characteristics. Kaplan-Meier curves and Cox proportional hazard regression were used to compare patients' survival and to identify independent risk factors for outcomes. There were 3048 patients (204 with Low- and 2844 with Ideal-DRWR). The Low-ratio group patients were older (8.3 vs. 6.9 yr; p = 0.001), there was a slight male predominance in the Low-DRWR group (p = 0.055). The Low-DRWR group had longer transplant wait time than the Ideal-DRWR group (97 vs. 85 days; p = 0.04). The groups did not differ in race, primary diagnoses, severity of pretransplant condition (medical urgency status, need for ventilation, inotropic support, ECMO, nitric oxide, or dialysis, the PVR for those with bi-ventricular anatomy), or post-transplant complications (length of stay, need for inotropic support, dialysis, and rate of infections). The Low-DRWR patients had less episodes of acute rejection during the first-post-transplant month. Infants with DRWR 0.5-0.59 had lower 30-day survival rate (p = 0.045). There was no difference in short- and long-term survival between the patients with DRWR 0.6-0.79 and DRWR 0.8-2.0. Use of smaller allografts (DRWR 0.6-0.8) has no negative impact on the short- and long-term survival of pediatric heart transplant patients.
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ABSTRACT: We aimed to evaluate the adaptive growth and remodeling behavior of the transplanted heart in pediatric heart-transplant recipients by comparing donor body surface area (BSA) and cardiac dimensions during transplantation with the corresponding parameters of the recipient over a period of time. A retrospective review of medical and echocardiographic records of 167 children (8.65 ± 5.98, median 9; range 0-17 years) who underwent orthotopic heart transplantation between 1987 and March 2010 was done. In the first 30 days post-transplantation, right- and left-ventricular end-diastolic diameters, volumes, and myocardial mass were found to be significantly increased (z score 3.96, p < 0.000) in relation to the recipients' BSA. Within the first year of post-transplantation, there was a significant reduction in the right-ventricular diameter (z score, -1.0 to +1.6, p = 0.000), left-ventricular diameter (z score -1.0 to +1.9, p = 0.000), right-ventricular end-diastolic volume (z score -1.3 to +1.9, p = 0.000) and left-ventricular end-diastolic volume (z score -1.3 to +1.8, p = 0.000), right-ventricular mass (z score, -1.4 to +1.7, p = 0.000) and left-ventricular mass (z score, -1.4 to +1.8, p = 0.000). During subsequent follow-up periods of 2-5 and 6-10 years, the aforementioned cardiac dimensions and volumes increased appropriately in accordance to the BSA (p = 0.000). In all the cardiac dimensions and volumes measured, donor-recipient mismatch did not influence the continuous growth of the measured parameters, which was in accordance to the recipients' BSA over time. Kaplan-Meier survival analysis showed a survival rate of 61.7% at 10 years. There is no statistically significant difference in survival rate among patients with varying donor-recipient weight ratios and donor-recipient BSA ratios (p = 0.53). This study demonstrates that the transplanted heart undergoes remodeling processes and grows adaptively, in accordance to the BSA, over a period of time.European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 09/2011; 40(6):1374-82; discussion 1382-3. · 2.40 Impact Factor
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ABSTRACT: Organ availability and acceptability limit pediatric HTx. What characteristics define an unacceptable or high-risk pediatric donor remains unclear. The purpose of this study was to characterize a large cohort of pediatric donors and determine the donor risk factors, including cumulative risk, that affect recipient survival. Data from the PHTS, a prospective multicenter study, were used to examine the impact of donor factors on the outcomes of patients listed <18 yr of age who received a HTx between 1993 and 2009. Donor data were available for 3149 of 3156 HTx (99.8%). Donor cause of death, need for inotropes, or CPR did not affect survival outcomes (p = 0.05). Ischemic time also did not have an impact on overall recipient survival; however, longer ischemic times negatively impacted one-yr post-transplant survival (p < 0.0001). There was no impact of cumulative risk factors on survival (p = 0.8). Although used in a minority of cases, hormonal therapy in the donor positively impacted survival (p = 0.03). In multivariate analysis, the only donor factor associated with decreased survival was smaller donor BSA, the other factors being related to the recipient characteristics. When analyzed by recipient age, there were no donor-related factors that affected survival for those who received a transplant at <6 months of age. Longer ischemic time (p < 0.0001) and greater age difference between the recipient and donor (p = 0.0098) were donor-related factors impacting early-phase survival for recipients who received a graft at ≥10 yr of age. Factors perceived to define a marginal or high-risk pediatric heart donor including inotrope use, CPR and donor cause of death may have less impact on outcomes than previously thought. Longer ischemic times did impact one yr, but not overall survival, and this impact was much greater with older donors. Parameters for accepting a donor heart can potentially be expanded, especially in the infant age group, but strong consideration should always be given to the interaction between ischemic time and donor age.Pediatric Transplantation 09/2013; · 1.50 Impact Factor
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ABSTRACT: The effect of organ-recipient gender match on pediatric heart transplant mortality is unknown. We analyzed the effects of gender and donor-recipient gender matching. Based on Organ Procurement and Transplant Network data, we performed a historical cohort study in a population of 3630 heart transplant recipients less than 18 years old. We compared unadjusted and adjusted mortality by recipient gender, donor gender and between gender-matched and gender-mismatched recipients. Female recipients had decreased survival compared to male recipients (unadjusted hazard ratio [HR] 1.16, confidence interval [CI] 1.02-1.31; p = 0.020). Organ-recipient gender mismatch did not affect mortality for either male or female recipients, though gender-mismatched females had the worst survival compared to gender-matched males, who had the best survival (unadjusted HR 1.26, CI 1.07-1.49; p = 0.005). After adjustment for other risk factors affecting transplant mortality, female recipients had decreased survival compared to male recipients (HR 1.27, CI 1.12-1.44; p = 0.020) and gender matching had no effect. In conclusion, gender mismatch alone did not increase long-term mortality for pediatric heart transplant recipients. However, there may be additive effects of gender and gender matching affecting survival. There are insufficient data at this time to support that recipient and donor gender should affect heart allocation in children.American Journal of Transplantation 10/2013; · 6.19 Impact Factor