Heart Transplant: Protocol for Monitoring Posttransplant Complications

Endomyocardial biopsy, first introduced in the posttransplant monitoring protocol by Billingham from Standford University, has become a necessity in the histological diagnosis, especially after the introduction of immunosuppressive treatment. Rejection is histologically illustrated by the occurrence of an interstitial and/or perivascular lymphocytic inflammatory infiltrate which, in severe cases, is associated with significant myocyte damage. In certain situations, the acute rejection is followed by irreversible damage, leading to patient’s death. The histological monitoring protocol was applied in 63 patients with heart transplant performed at the Emergency Institute for Cardiovascular Diseases and Transplant of Targu Mures, between 1999 and the present time. Six of these interventions were performed in 2016. Twenty-two of the 63 patients deceased during follow-up due to various complications, whereas 32 were diagnosed with cytomegalovirus infection, based on clinical and histological findings. All patients underwent biopsy at various intervals of time, either following a standardized protocol or driven by the lesion pattern revealed by the pathological report. Three to six tissue samples were fixed in 10% buffered formaldehyde prior to paraffin embedding. Paraffin blocks were sectioned at three or four levels. Hematoxyllin-eosin, trichrome Masson and methyl-pyronin green staining were used.

Conclusion: Endomyocardial biopsy monitoring of heart transplant recipients is still the most important tool for the complex diagnosis of post-transplant complications, facilitating the adoption of timely and targeted therapeutic intervention, and the permanent improvement of immunosuppressive therapeutic protocols, with the goal of increasing survival time.

Keywords: Cardiac transplantation, Acute rejection, Chronic rejection, Intramyocardial biopsy