Postmarket surveillance for drug-eluting coronary stents: a comprehensive approach.

The development and introduction of new medical devices have radically changed the practice of medicine. No area of medicine has been affected more than cardiology, with new devices facilitating the effective treatment of coronary artery disease (percutaneous coronary interventions [PCIs]/ stents), valvular heart disease (mechanical and bioprosthetic valves), and electrophysiological disorders (pacemakers and automatic implantable cardiodefibrillators). In addition to fueling the growth of the medical device industry, this explosion of technology has driven the development of new medical subspecialties, eg, interventional cardiology and electrophysiology. Other areas of medicine, including orthopedics and general surgery, have witnessed similar transformations. The current regulatory pathway for a significant-risk first-in-class medical device is typically a long, expensive, and risky process, culminating in a pivotal trial designed to demonstrate safety and efficacy. The pivotal trial phase is typically the most time-consuming and costly phase of the process. In the United States, medical devices are regulated by the Center for Devices and Radiological Health at the Food and Drug Administration (FDA), which has been charged by Congress to seek the “least burdensome means” when determining the scope of data required to evaluate the safety and efficacy necessary for device approval.1 Thus, pivotal trials by intention are designed to select patient cohorts most likely to demonstrate procedural benefit while limiting patient/study subject risk within the shortest time frame that can provide meaningful data. The realities of logistics, time, and resources limit the size and duration of most new device trials to 800 to 1500 patients, limiting the power of these trials to detect events with an occurrence rate of 1%. Furthermore, pivotal trials are conducted by the most experienced physician operators at medical centers with sufficient patient volume and research infrastructure to recruit and conduct clinical studies. Some have questioned whether results obtained under these settings from such narrowly defined patient subsets can be extrapolated to the “realworld” postapproval environment. In recognition of these limitations, it is frequently desirable to collect additional data on device performance after FDA approval for commercial release, ie, postmarket surveillance. The need for accurate, timely, and comprehensive postmarket surveillance has been highlighted by the recent introduction of drug-eluting stents into general clinical use.2