Use of Donor Hearts with Low Ejection Fraction in Pediatric Heart Transplantation: A PHTS Analysis

Abstract

<h3>Purpose</h3> Despite a growing number of children awaiting heart transplant (HT), annual number of HT is relatively unchanged and waitlist mortality is high especially in infants. Donor heart discard rate is also high with ventricular dysfunction as a major reason. Use of donors with low ejection fraction (DLEF) is rare (<15%) in pediatric HT. We evaluated the use of DLEF in pediatric HT using the Pediatric Heart Transplant Society (PHTS) Database. <h3>Methods</h3> PHTS Database was queried from 1/1993 to 12/2020. DLEF was defined as: donor with left ventricular ejection fraction (LVEF) on pre-procurement echo <54% with wall motion abnormality or LVEF <50% irrespective of wall motion abnormality Donor and recipient characteristics, graft survival and trends of DLEF use across regions and eras were compared. <h3>Results</h3> Of 7520 pediatric HT, 7237 (96%) had a donor echo report but only 6332 (84%) had a LVEF reported. Of these, 143 (2.3%) were DLEF with median LVEF 47% [IQR 44-50%]. Focal or diffuse wall motion abnormality was seen in 35 (24%) and 23 (16%) had abnormal septal motion. Recipient characteristics between groups including age, diagnosis, end-organ function, use of VAD and/or ECMO at listing or transplant were similar. Mechanical ventilation at HT (p=.0082), earlier era (p<.0001), and regional variation (p<.0001) were associated with increased use of DLEF. Donor characteristics were similar with the exception that DLEF were more likely to be on epinephrine (20.7% vs 9.9%, p=<.0001) and/or vasopressin (73% vs 54%, p=.0018). DLEF use decreased over time (1993-2002: 4.26%; 2003-12: 2.18%; 2013-20: 1.6%). Differences were seen across UNOS regions (Region 4 vs 10: 0.9% vs 4.2%, p=<.0001). Graft survival at 3 months post-HT was similar for DLEF vs non-DLEF donors (91% vs. 94%, logrank p=0.1) (Fig 1). <h3>Conclusion</h3> Use of DLEF in pediatric HT is limited and lower than previously reported. Use of DLEF has decreased over time. DLEF had comparable graft survival at 3 months post-HT, supporting efforts to expand the use of DLEF in pediatric HT.