The heart of a pediatric transplant recipient whose donor heart was
implanted on top of her own heart has regained normal cardiac function.
According to study results published in The Lancet, the
patient presented with signs of severe HF at 8-months-old and underwent a
heterotropic cardiac transplantation at 11 months. In the years following the
pediatric transplant procedure, the female patient developed respiratory
problems and recurrent post-transplant lymphoproliferative disorder stemming
from an Epstein-Barr virus that was resistant to several therapies. The patient
eventually developed cancer from the cyclosporine and azathioprine she took for
immunosuppression. As a result, she was treated periodically with therapies
including chemotherapy and rituximab (Rituxan, Biogen Idec, Genetech).
The donor heart was removed without complication 10.5 years
post-implantation. According to the researchers, the patient is currently in
complete remission from her post-transplant lymphoproliferative disorder, and
the cardiac function of her heart is normal more than three years after the
removal of the donor heart.
The researchers said that their findings highlighted a number of
important issues regarding pediatric heterotopic cardiac transplantation,
myocardial recovery and the management of post-transplant lymphoproliferative
disorder.
“The late recovery of function in idiopathic cardiomyopathy might
occur many years after the initial presentation, and in this situation, the
removal of a heterotopic transplant is technically feasible,” the
researchers wrote in the study. “A difficult balance needs to be achieved
in patients who develop post-transplant lymphoproliferative disorder between
sufficient reduction of immunosuppression to control post-transplant
lymphoproliferative disorder, while maintaining enough immunosupression to
prevent rejection, and that even low-dose immunosuppression might prevent the
function of Epstein-Barr virus-specific T-cells in vivo, a finding which has
important implications for adoptive immunotherapy for post-transplant
lymphoproliferative disorder.” – by Eric Raible
Tsang V. Lancet. 2009;doi:10.1016/S0140-6736(09)61201-0.
The procedure is remarkable for at least three reasons: the use of a
smaller heterotopic transplant heart as a piggyback support for a larger
failing heart (we would probably use an LVAD for that today); the removal of
that transplant to be able to stop the immunosuppressive therapy causing the
post-transplant lymphoproliferative disorder associated with Epstein-Barr
virus; and the reverse remodeling of the failing heart when unloaded and given
a period of time to recover. Of these, the latter to me is most significant
because it shows that the heart has reparative powers under certain
circumstances. If we understood that mechanism, we might be able to capture it
as therapy for other cardiac disorders.
–
Douglas P. Zipes, MD
Cardiology Today Section Editor
