Abstract 2007: Rejection With Hemodynamic Compromise in the Current Era of Pediatric Heart Transplantation: A Multi-institutional Study
Background: Survival after pediatric heart transplant has improved over time. Recent data suggests a decrease in rejection rates in the current era. This study attempts to understand whether a similar effect exists for rejection associated with heart failure (rejection with hemodynamic compromise, RHC).
Methods: Data from 2156 patients transplanted between 1/93 and 12/2006 at 33 centers in the Pediatric Heart Transplant Study (PHTS) were analyzed to determine the incidence, outcome, and risk factors for occurrence of RHC in early (1/93 -12/99) and recent (1/00 -12/06) eras. Rejection was a clinical event determined by biopsy, echo, or clinical findings that led to augmentation of immunosuppression. RHC was defined as an episode associated with new heart failure. RHC was deemed mild (MRHC) or severe (SRHC) depending on whether inotropic support was (SRHC) or was not (MRHC) used.
Results: Of 1248 patients with any episode of rejection, 580 had RHC (214 with SRHC; 366 with MRHC). Overall, the incidence of RHC decreased significantly at 1 yr (85% vs 75%, p<0.001) and at 5 yrs (73% vs 63%, p<0.001). However, freedom from SRHC (95% vs 93%) at 1 yr and (87% vs 85%) at 5 yrs after transplant was not significantly different (p=0.12) between eras. Survival after SRHC was 63% at 1 yr and 48% at 5 yrs, significantly worse than survival after MRHC (87% at 1 yr and 72% at 5 yrs, p<0.001). Era and previous rejection before SRHC did not affect survival after SRHC. Risk factors associated with occurrence of SHRC in the multivariate analysis were non-white race (HR: 1.62, 95%CI: 1.20 to 2.19, P=0.001); <6 months of age at transplant (HR 0.54, 95%CI: 0.36 – 0.79, P=0.002), and blood type other than A (HR: 1.4, 95%CI: 1.03 to 1.9, P=0.034). In contrast, the multivariate analysis of MRHC showed only an effect of earlier era (HR: 1.94, 95%CI: 1.56 to 2.41, p <0.001).
Conclusions: Despite a decrease in overall rejection and MRHC, the incidence of SRHC has not changed over time and continues to be associated with high mortality. As SRHC differs in risk factors and survival from MRHC, these entities may not represent different points on a continuum of rejection severity but may be distinct clinical phenomena requiring different strategies for prevention or treatment.