Withdrawal of proliferation signal inhibitors due to adverse events in the maintenance phase of heart transplantation.

Background: The increasing use of proliferation signal inhibitors (PSIs) has raised the issue of their risk profile. We sought to determine the causes, incidence, risk factors, and consequences of withdrawal due to adverse events of PSIs in maintenance heart transplantation.
Methods: This was a retrospective study from 9 centers of the Spanish Registry for Heart Transplantation. Demographic, clinical, analytic, and evolution data were obtained for patients in whom a PSI (sirolimus or everolimus) was used between October 2001 and March 2009.
Results: In the first year, 16% of 548 patients could not tolerate PSIs. This incidence rate stabilized to 3% to 4% per year thereafter. The most frequent causes for discontinuation were edema (4.7%), gastrointestinal toxicity (3.8%), pneumonitis (3.3%), and hematologic toxicity (2.0%). In multivariate analysis, withdrawal of PSI was related to the absence of statin therapy (p = 0.006), concomitant treatment with anti-metabolites (p = 0.006), a poor baseline renal function (p = 0.026), and multiple indications for PSI use (p = 0.04). Drug discontinuation was associated with a decline in renal function (p = 0.045) but not with an excess in mortality (p = 0.42).
Conclusions: In this large cohort of maintenance heart transplant recipients taking a PSI, 16% withdrew treatment in the first year, and 25% had stopped PSI due to severe adverse events by the fourth year. This high rate of toxicity-related PSI withdrawal could limit the clinical utility of this otherwise novel class of immunosuppressive agents.
(Copyright © 2012 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)