The impact of ischemic time on early rejection after pediatric heart transplant

Abstract

Prolonged graft ischemia may be a risk factor for early rejection post-HTx, but this has not been well studied in children. Furthermore, factors moderating the association between IT and early rejection have not been investigated. From 2004 to 2012, pediatric HTx recipients (n = 2381) were identified from the UNOS database. A ROC curve determined the optimal IT discriminating patients by the presence of early rejection. Separate univariate analyses identified factors associated with: (i) early (prior to hospital discharge) rejection, and (ii) IT. A multivariable logistic regression assessed independent risk factors for early rejection. We included interaction terms to evaluate whether IT's independent risk effect on early rejection is moderated via interaction with associated factors found in univariate analysis. Longer IT was associated with an increased risk of early rejection. In multivariable analysis, IT > 3.1 hours was an independent risk factor for early rejection (AOR 1.44, P = .01). No interaction terms between IT and any associated factors were significant. Longer IT is an independent risk for early rejection in pediatric HTx recipients. Better understanding the association between IT and early rejection may identify interventions to mitigate this risk.

Effect of ischemic time on pediatric heart transplantation outcomes: is it the same for all allografts?

“…In one study, prolonged IT (>3.1 h) was found to increase the risk of early graft rejection, prior to hospital discharge. 5 Similarly, continuous IT increase F I G U R E 3 (A) Kaplan-Meier curve; overall survival analysis of patients according to donor LVEF value (LVEF < 65% and ≥65%). (B) Kaplan-Meier curve; overall survival analysis of patients according to organ IT categories was associated with an increase in post-transplantation length of stay, 1-year and 5-year mortality risk.…”

“…Donors with hearts having a LVEF ≥65% were younger than those with a LVEF < 65%, with a median age of 5 [0-14] compared with 8 years [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] (p < .001). Also, those with a higher IT were found to be younger with a median age of 3 years [0-10] compared with 5 [1-14] and 7 years [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] in transplants with an IT >6, 4-6, and <4 h, respectively (p < .001; Tables 1 and 2).…”

“…Compared with patients receiving hearts with LVEF < 65%, PHT recipients of hearts with a LVEF ≥ 65% were younger (median age of 4 years [IQR 0-12] versus 7 years [1][2][3][4][5][6][7][8][9][10][11][12][13][14]; [p < .001]), more likely to be diagnosed with CHD (p < .001), and less likely to be on chronic steroid use (p = .048; Table 1).…”

“…This is due to evidence from several reports showing that longer ITs (>3-4 h) increase the risk of early graft rejection. 2,4,5 In fact, prolonged ischemia time (>4 h) was found to be an independent risk factor increasing 1-and 5-year mortality and prolonging hospital stay. 2 Also, an ischemia time of 3.5 h or more has been shown to increase graft loss by 30% within the first 6 months post-transplantation.…”

Pediatric donor heart allocation in the United States, 2006‐2017: Current patterns and potential for improvement

“…Many different criteria have been previously cited as indicative of poor organ quality including low ejection fraction, high vasopressor use, organ ischemic time, and others. However, observational studies of short‐ and long‐term outcomes for adult and, now pediatric, transplant patients receiving these potentially less desirable organs have not convincingly demonstrated negative consequences for the use of these organs 9‐12 . In fact, based on the available literature, new guidelines for pediatric organ suitability for transplant have been recently published, stating that, in the setting of normal function, other considerations of organ health are largely immaterial 4 .…”