Valve function during graft rejection and before graft failure in pediatric heart transplant recipients

Management of immunosuppression after human valve transplant remains unclear and may be aided by understanding valve function during rejection and with chronic graft failure after heart transplant. We assessed valve function during biopsy-diagnosed rejection and before death/retransplantation in pediatric heart transplant recipients.

This was a single-center, retrospective study. Patients in cohort 1 had 2 serial biopsies showing nonrejection followed by rejection and concurrent echocardiograms. Cohort 2 had graft loss (death or retransplant) with a pre-event echocardiogram.

In cohort 1 (n = 86), the median age at heart transplant was 12.0 years, and the median time between heart transplant and rejection was 2.6 years. No patient had more than trivial aortic regurgitation at baseline or during rejection. Mild pulmonary regurgitation was present in 2 patients (2.3%) at baseline and 4 patients (4.8%) during rejection (P = .10). Patients with mild or greater mitral regurgitation increased from 13 patients (15.1%) at baseline to 29 patients (33.7%) during rejection (P < .001). Worse mitral regurgitation during rejection was more likely in conjunction with moderate or greater left ventricular dysfunction (64.8% vs 8.7%, P < .001). In cohort 2 (n = 51), the median duration between heart transplant and graft loss was 8.4 years. Mild or greater aortic regurgitation was present in 1 patient (2.0%), pulmonary regurgitation mild or greater was present in 4 patients (7.8%), and mitral regurgitation mild or greater was present in 20 patients (39.2%). No patient developed valve stenosis.

In a series of more than 100 pediatric heart transplant recipients, semilunar valve dysfunction was rare, suggesting that contemporary immunosuppression is sufficient to preserve the longevity of semilunar valve transplants. Mitral valve dysfunction was more common, often associated with left ventricular dysfunction, and warrants further study.