Which effect is associated with the use of mammalian target of rapamycin (mTOR) inhibitors in cardiac transplant patients?

The use of mammalian target of rapamycin (mTOR) inhibitors in cardiac transplant patients is primarily associated with a lower incidence of coronary allograft vasculopathy (CAV), which is a significant complication following heart transplant procedures. CAV is characterized by vascular remodeling that results in obstructive lesions in the coronary arteries of the transplanted heart, contributing to morbidity and mortality in these patients.

mTOR inhibitors work by inhibiting certain cellular pathways that contribute to cell growth and proliferation, particularly in immune cells. This mechanism has been found to not only provide immunosuppression but also to have favorable effects on the vascular biology pertinent to transplanted hearts. By reducing the hyperproliferation of vascular smooth muscle cells, mTOR inhibitors help in minimizing the progression of CAV.

While other factors such as the risk of infections or malignancies might be of concern with the overall immunosuppressive therapy used in transplant patients, the specific advantage of mTOR inhibitors is their potential to improve vascular health in the transplanted organ, thereby reducing the risk of CAV, which is what makes this effect particularly vital in the context of cardiac transplantation.