Suppressive effects of conversion from mycophenolate mofetil to everolimus for the development of cardiac allograft vasculopathy in maintenance of heart transplant recipients

Background Whether converting to everolimus (EVL) from mycophenolate mofetil (MMF) during the maintenance period after heart transplantation (HTx) reduces cardiac allograft vasculopathy (CAV) progression remains unclear. We sought to determine the effect of converting from MMF with standard-dose calcineurin inhibitors (CNIs) to EVL with low-dose CNIs on CAV progression. Methods We retrospectively reviewed the medical records of 63 HTx recipients who survived at least at 1 year after HTx. Twenty-four recipients were converted from MMF to EVL (EVL group, 2.2 ± 2.3 years after HTx), while 39 recipients were maintained on MMF (MMF group, 2.4 ± 2.2 years after HTx). The EVL group underwent three-dimensional intravascular ultrasound (3D-IVUS) analysis before and 1 year after conversion to EVL, and these data were compared with data from 2 consecutive IVUS in the MMF group. Results IVUS indices in the EVL group at 1 year after conversion did not show increased CAV development, whereas a significant increase in %plaque volume (p = 0.006) and decrease in lumen volume (p < 0.001) were observed in the MMF group. EVL conversion was significantly associated with smaller increases in %plaque volume (p = 0.004) and smaller decreases in lumen volume (p = 0.017). IVUS indices in the late EVL conversion group (≥ 2 years) also did not exhibit increased CAV development, while those in the MMF group did. Conclusions Conversion to EVL from MMF in maintenance periods after HTx may decrease the rate of CAV progression based on IVUS indices.