Development and validation of a major adverse transplant event (MATE) score to predict late graft loss in pediatric heart transplantation.

2018

441-450

2018 Apr

1557-3117

<p><strong>BACKGROUND: </strong>There is inadequate power to perform a valid clinical trial in pediatric heart transplantation (HT) using a conventional end-point, because the disease is rare and hard end-points, such as death or graft loss, are infrequent. We sought to develop and validate a surrogate end-point involving the cumulative burden of post-transplant complications to predict death/graft loss to power a randomized clinical trial of maintenance immunosuppression in pediatric HT.</p>

<p><strong>METHODS: </strong>Pediatric Heart Transplant Study (PHTS) data were used to identify all children who underwent an isolated orthotopic HT between 2005 and 2014 who survived to 6 months post-HT. A time-varying Cox model was used to develop and evaluate a surrogate end-point comprised of 6 major adverse transplant events (MATEs) (acute cellular rejection [ACR], antibody-mediated rejection [AMR], infection, cardiac allograft vasculopathy [CAV], post-transplant lymphoproliferative disease [PTLD] and chronic kidney disease [CKD]) occurring between 6 and 36 months, where individual events were defined according to international guidelines. Two thirds of the study cohort was used for score development, and one third of the cohort was used to test the score.</p>

<p><strong>RESULTS: </strong>Among 2,118 children, 6.4% underwent graft loss between 6 and 36 months post-HT, whereas 39% developed CKD, 34% ACR, 34% infection, 9% AMR, 4% CAV and 2% PTLD. The best predictive score involved a simple MATE score sum, yielding a concordance probability estimate (CPE) statistic of 0.74. Whereas the power to detect non-inferiority (NI), assuming the NI hazard ratio of 1.45 in graft survival was 10% (assuming 200 subjects and 6% graft loss rate), the power to detect NI assuming a 2-point non-inferiority margin was &gt;85% using the MATE score.</p>

<p><strong>CONCLUSION: </strong>The MATE score reflects the cumulative burden of MATEs and has acceptable prediction characteristics for death/graft loss post-HT. The MATE score may be useful as a surrogate end-point to power a clinical trial in pediatric HT.</p>

10.1016/j.healun.2017.03.013

28465118

Use of sirolimus in pediatric heart transplant patients: A multi-institutional study from the Pediatric Heart Transplant Study Group.

2016

2016 Oct 04

1557-3117

<p><strong>BACKGROUND: </strong>Proliferation signal inhibitors, such as sirolimus, are increasingly used in solid-organ transplantation. However, limited data exist on sirolimus-treated pediatric patients. We aimed to describe sirolimus use in pediatric heart transplant patients and test the hypothesis that sirolimus use is associated with improved outcomes.</p>

<p><strong>METHODS: </strong>A retrospective review and propensity-matched analysis of the Pediatric Heart Transplant Study database was performed on patients undergoing primary heart transplantation from 2004 to 2013 with at least 1 year of follow-up comparing patients treated vs not treated with sirolimus at 1 year after transplant. The primary outcome of interest was patient survival, with secondary outcomes including cardiac allograft vasculopathy, rejection, malignancy, and renal insufficiency.</p>

<p><strong>RESULTS: </strong>Between 2004 and 2013, 2,531 patients underwent transplantation. At least 1 year of follow-up was available for 2,080 patients, of whom 144 (7%) were on sirolimus at 1 year post-transplant. Sirolimus-treated and non-treated patients had similar survival in the overall cohorts and in the propensity-matched analysis. The secondary outcomes measures were also similar, including a composite end point of all outcome measures. There was a trend toward increased time to cardiac allograft vasculopathy (p = 0.09) and decreased time to infection (p = 0.05) among sirolimus-treated patients in the overall cohort (p = 0.19) but not in the propensity-matched cohort (p = 0.17).</p>

<p><strong>CONCLUSIONS: </strong>Sirolimus was used in less than 10% of patients at 1 year post-transplant. Overall outcomes of sirolimus treated and non-treated patients were similar with respect to survival and major transplant adverse events. Further study of sirolimus in pediatric heart transplant patients is needed.</p>

10.1016/j.healun.2016.09.009

J. Heart Lung Transplant.

28029575