Drug-Eluting Stents in Preclinical Studies: Recommended Evaluation From a Consensus Group

The arrival of drug-eluting stents raises important questions about preclinical evaluation of devices and the optimal means of predicting clinical safety and efficacy. The Interventional, Regulatory, Commercial, and Scientific communities have all asked for assistance in defining criteria for device evaluation. This document is an integrated view of requirements for evaluating drug-eluting stents in preclinical models. The suggested requirements encompass study design, experimental performance, and histopathologic evaluations, emphasizing safety and efficacy at multiple points in time. This is a consensus document assembled by clinical, academic, and industrial investigators engaged in preclinical interventional device evaluation. Suggested requirements might well serve as a standard but do not prescribe a single manner in which all devices should be evaluated. They instead motivate such an evaluation and describe how examinations might be performed. It is understood that methods will change and knowledge will evolve, in particular as corroboration is established with clinical data. The dynamic nature of this document allows for future modifications and additions. A drug-eluting stent presents or releases single or multiple bioactive agents into the blood stream. The drug can deposit in and/or affect blood vessels, cells, plaque, or tissues either adjacent to the stent or at a distance. Systemic drug concentrations may be avoided or desirable. It is assumed that drugs undergoing preclinical evaluation will have sound theoretical and practical reasons for biological success, and that the preclinical studies will help answer the magnitude and safety of effect when presented with or from the stent. It is likely that substantial empirical data already exists documenting the effects of these drugs on isolated cells in culture and even in vivo after systemic administration. Some drugs may already be in clinical use. Drug can be embedded and released from within (“matrix-type”) or surrounded by and released through (“reservoir-type”) polymer materials that coat …