Monitoring of cyclosporine 2-hr post-dose and trough levels in heart transplantation

Recommendations for Use of Everolimus After Heart Transplantation: Results From a Latin-American Consensus Meeting

Despite improvements during the last decades, heart transplantation remains associated with several medical complications, which limit clinical outcomes: acute rejection with hemodynamic compromise, cytomegalovirus (CMV) infections, allograft vasculopathy, chronic renal failure, and neoplasias. Everolimus, a proliferation signal inhibitor, represents a new option for adjunctive immunosuppressive therapy. Everolimus displays better efficacy in de novo heart transplant patients than azathioprine for prophylaxis of biopsy-proven acute rejection episodes of at least ISHLT grade 3A (P < .001), of allograft vasculopathy (P < .01), and of CMV infections (P < .01). These findings suggest that everolimus potentially play an important role as part of immunosuppressive therapy in heart transplant recipients. Heart transplant investigators from Latin America produced recommendations for everolimus use in daily practice based on available data and their own experience.

Recommendations for Use of Certican® (Everolimus) After Heart Transplantation: Results From a German and Austrian Consensus Conference

The Certican Consensus Conference has produced guidelines to help physicians apply Certican (everolimus) clinical trial data in clinical practice. Everolimus is indicated in combination with cyclosporine microemulsion (CsA; Neoral) and corticosteroids for prophylaxis of acute rejection after heart transplantation. It has also shown efficacy for prevention of cardiac allograft vasculopathy. Further indications for use pertain to patients with chronic renal failure, to allow reduced calcineurin inhibitor (CNI) exposure; reduce the risk of cytomegalovirus to disease; second transplantation; heart/lung transplantation after occurrence of bronchiolitis obliterans; and in patients with malignancies under immunosuppression. Contraindications include intolerance, severe leukocytopenia and severe thrombocytopenia. The everolimus dose is 0.75 or 1.5 mg twice daily, adjusted according to trough blood levels. Target blood levels are 3 to 8 ng/ml, with 6 to 8 ng/ml considered the optimal range for most patients. Recommended CsA trough blood levels in patients receiving everolimus are 150 to 175 ng/ml for Months 1 to 3 post-transplant, around 135 ng/ml for Months 3 to 6, and <100 ng/ml after Month 6. It may be possible to discontinue steroids in patients receiving long-term everolimus and CsA. Early cytomegalovirus prophylaxis is recommended for patients with a high-risk mismatch, and trimethoprim-sulfamethoxazole should be given to prevent Pneumocystis carinii. Everolimus dose should be reduced by about 50% if administered in conjunction with azoles or erythromycin, and increased 100% to 200% if given with rifampicin. All heart transplant recipients should receive statins unless contraindicated.

History of C2 monitoring in heart and liver transplant patients treated with cyclosporine microemulsion

Therapeutic drug monitoring of CsA has evolved since the introduction of CsA microemulsion. The purpose of the present review is to summarize the history of CsA concentration 2 hours postdose (C2) monitoring in heart and liver transplantation. C2 has been shown to be the best single time point that correlates with the area-under-the-curve, with a correlation coefficient (r2) ranging between .83 and.93. C2 monitoring (300 to 600 ng/mL) has resulted in a significant clinical benefit in long-term heart and liver transplant patients compared to trough level (C0) monitoring. Moreover, a C2 range of 300 to 600 ng/mL resulted in a similar calcineurin inhibition compared to a C2 range of 700 to 1000 ng/mL or a C0 range of 100 to 200 ng/mL while being less injurious to renal function. In de novo liver transplant patients not receiving induction therapy, the achievement of a target C2 of 850 to 1400 ng/mL by postoperative day 3 has resulted in a low acute rejection rate. Furthermore, C2 monitoring has been associated with a lower rejection rate in hepatitis C virus (HCV)-negative patients and with an overall lesser severity of acute rejection compared to C0 monitoring. In de novo heart transplant patients who receive antithymocyte globulin induction, a lower C2 range may be sufficient to prevent rejection and renal dysfunction. Future studies should help to fine-tune the optimal C2 range in heart or liver transplant patients receiving induction therapy and different maintenance immunosuppressive combinations.

Optimizing the immunosuppressive regimen in heart transplantation

The use of immunosuppression regimens containing a calcineurin inhibitor (CNI), an adjunct immunosuppressant (e.g., azathioprine, everolimus or mycophenolate mofetil) and corticosteroids has effectively reduced the risk of early graft loss due to acute rejection in heart transplant recipients. At present, late graft loss due to cardiac allograft vasculopathy (CAV) remains a major challenge for transplant teams. CAV is characterized by intimal hyperplasia as a result of endothelial cell injury. Factors relating to the transplant procedure itself (e.g., ischemic time and reperfusion injury), cardiovascular risks (e.g., donor age, hypertension, hyperlipidemia, pre-existing diabetes and new-onset diabetes after transplantation), immunologic risks (e.g., acute rejection episodes, anti-HLA antibodies) and the side effects of immunosuppression with CNIs or corticosteroids (e.g., cytomegalovirus infection, nephrotoxicity) have all been implicated in the development of CAV. The 2 main approaches to the prevention of CAV are modification of underlying risk factors (e.g., treatment with anti-hypertensive agents and lipid-lowering drugs, and optimizing the immunosuppressive regimen) and improvement in immunosuppression. CNIs remain the cornerstone of immunosuppressive regimens in heart transplantation, but new parameters for monitoring CNI exposure and new immunosuppressive regimens hold the promise of reduced overall CNI exposure with consequent reductions in vascular toxicity and improved clinical outcomes. Traditionally, trough levels of cyclosporine (C(0)) have been used to monitor exposure to cyclosporine and to assess the need for dose adjustment. However, optimal cyclosporine exposure can now be achieved through monitoring of cyclosporine levels 2 hours after dosing (C(2) monitoring). Furthermore, in a pivotal trial in heart transplantation, the new proliferation signal inhibitor, everolimus, plus full-dose cyclosporine and corticosteroids, has been shown to have improved impact on prevention of biopsy-proven acute rejection (and other efficacy end-points) and longer term on the prevention of CAV. In addition, there is evidence from studies in renal transplant recipients that everolimus plus reduced exposure cyclosporine is effective and well tolerated-with the regimen having a reduced potential for CNI-related nephrotoxicity and for other CNI-related cardiovascular side effects.

The promise of C2, simulect, and certican in heart transplantation

Immunosuppressive therapy in clinical transplantation has evolved from general nonspecific suppression of the immune system to selective blockade of intracellular immune events, maximizing graft tolerance while minimizing toxicity. Cyclosporine 2-hour postdose level monitoring has been recommended as the single most sensitive sampling point for assessment of the area under the curve, and predictor of clinical outcomes in heart transplantation. Strategies for monitoring immunosuppressive drugs to improve efficacy without increased toxicity are critical as we move into the 21st century. Everolimus, a derivative of rapamycin, is a macrocyclic immunosuppressive agent with antiproliferative activity that is efficacious in preventing graft vasculopathy. Agents that increase the armamentarium against rejection allowing individualized therapy tailored to minimize complications, and prevent graft vasculopathy will improve our flexibility and may translate into improved long-term outcomes.