Defining device success for percutaneous coronary intervention trials

Percutaneous coronary intervention with implantation of drug-eluting stents has become the most commonly performed revascularisation procedure in patients with symptomatic coronary artery disease. Continuous iterations of coronary devices incorporating changes in platform materials, geometry, strut thickness, drug release mechanisms and antiproliferative drugs have progressively reduced the rate of device-related adverse clinical events. Objective performance criteria have been proposed for clinical and angiographic outcomes of drug-eluting stents. The rate of device success has been recognised as an intraprocedural endpoint to evaluate the mechanical ability to complete a procedure with the specific device assigned by protocol in randomised comparative trials. The European Commission and the U.S. Food and Drug Administration both provide guidance documents, including the mechanistic evaluation of coronary stents, which recommend operational definitions of device success. While the majority of clinical trials investigating drugeluting stents have adopted this endpoint definition, inconsistencies in application limit the reliability of comparisons across different trials reporting device success rates. In addition, it is not uncommon that device success rates are not reported by investigators. A consistent definition of device success is essential to allow scientific comparisons of this technical performance endpoint between devices across different trials. Therefore, we performed a systematic evaluation of definitions and reporting of device success in clinical trials. We propose an extended definition as well as considerations for approaching the determination of the device success rates in future percutaneous coronary intervention trials.