Abstract 3530: Viral Endomyocardial Infection in the 1st Year Post-Transplant is Associated With Persistent Inflammation in Pediatric Heart Transplant Patients
Introduction: Viral genome in the cardiac allograft has been associated with early graft loss in pediatric heart transplant (PHT) patients. The mechanism for graft loss is unknown. We tested the hypothesis that PHT patients with virus identified in the myocardium in the first year post-transplant would have increased inflammation and worse hemodynamics compared to patients that were virus free.
Methods: A retrospective review of PHT patients at our institution from 1/2004 and 5/2008 was performed. Patients underwent serial cardiac catheterizations with endomyocardial biopsies to evaluate for rejection and the presence of virus by PCR. Rejection was graded on the Texas Heart Institute - McAllister scale (a 10 point scale with higher scores indicating more inflammation). Patients with virus identified at any time during the first year post-transplant were compared at one year post-transplant to virus free patients.
Results: 59 patients comprised the cohort, median age at transplant 5.1 years [interquartile range (IQR) 1.2 to 12.2 years]. Viral genomes were isolated from 19 (32%) patients, with parvovirus B19 being the most frequently detected (n=15, 79%). The PCR + group had an increased degree of inflammation on endomyocardial biopsy at one year post-transplant, median score 4 (IQR 1 to 4) compared to the PCR − group, median score 1 (IQR 0 to 4) (p=0.014). The PCR + group had similar cardiac index, median 3.7 ml/min/m2 (IQR 3.0 to 4.5), pulmonary capillary wedge pressure, median 10 mmHg (IQR 7 to 11), and pulmonary vascular resistance index, median 1.7 U·m2 (IQR 1.1 to 2.4) compared to the PCR − group, median cardiac index 3.2 (IQR 2.8 to 3.7), median pulmonary capillary wedge pressure 8 (IQR 7 to 11), and median pulmonary vascular resistance index 1.7 (IQR 1.2 to 2.1). There was a trend towards worsening renal function in the PCR group, median creatinine 0.7 mg/dl (IQR 0.5 to 0.9) compared to the PCR − group, median creatinine 0.5 (IQR 0.4 to 0.6) (p=0.056).
Conclusions: PHT patients with viral endomyocardial infections have evidence of increased allograft inflammation compared to virus free patients. However, the hemodynamic profile is similar between the groups. Ongoing subclinical inflammation may contribute to the early graft loss associated with these patients.