FK778 attenuates cytomegalovirus-enhanced vein graft intimal hyperplasia in a rat model

Background: Venous grafts are commonly used to treat drug-resistant coronary artery disease, although long-term functionality is limited because of proliferation and migration of smooth muscle cells (SMC). As proliferating SMC are particularly susceptible for the stimulating effects of cytomegalovirus (CMV), we hypothesized that CMV Infection may enhance cell proliferation and graft failure. Furthermore, we evaluated the potential of FK778 to prevent intimal hyperplasia. Apart from its Antiviral properties, FK778 is a new immunosuppressive agent which may also affect SMC proliferation, making it an interesting drug to prevent (CMV-enhanced) venous graft intimal hyperplasia.

Methods: Epigastric vein-to-common femoral artery interposition grafts were placed in four groups of 10 rats each. Rats received either FK778 (oral treatment, 15 mg/kg), were infected with CMV (1.25 x 10(6) plaque-forming units) or were both treated and infected.

Results: CMV Infection resulted in a significant increase in intimal and medial cross-sectional area and medial wall thickness of the vein grafts. This effect was diminished by administration of FK778. Moreover, FK778 treatment alone resulted in a significant decrease in neointimal area and percentage of stenosis versus the control group.

Conclusions: These data suggest a role of CMV in venous graft failure. Also, our results suggest a prospective role for the new immunosuppressive drug FK778 in the prevention of (CMV-mediated) vein graft intimal hyperplasia.