Calcineurin-inhibitor minimization protocols in heart transplantation

Cardiac transplantation has become an established method for end-stage heart disease. A calcineurin-inhibitor (CNI)-based regimen is the cornerstone of immunosuppressive therapy after cardiac transplantation. CNIs have reduced acute rejection and infection and markedly increased survival of cardiac transplantation patients. However, the dose- and time-dependent nephrotoxic effects of CNIs can limit long-term survival, and chronic renal failure is a major cause of morbidity and mortality in long-term cardiac transplant patients. Early experience on withdrawal of CNIs (and maintenance of patients on azathioprine and steroids) in patients, who developed chronic renal dysfunction, resulted in rejection episodes with, sometimes, fatal outcome. The introduction of newer immunosuppressive drugs, like thymoglobulin, anti CD-25 monoclonal antibodies, mycophenolate mofetil, everolimus or sirolimus into clinical practice, has given transplant physicians new tools to adapt immunosuppression to patients' needs. Changes of immunosuppressive protocols by using new drugs early and late after transplantation and simultaneous reduction or weaning of CNIs have become attractive options. The aim of this article is to review strategies to delay, reduce or prevent CNIs after cardiac transplantation as means to improve short- and long-term outcome mainly by protecting renal function.