Drug-eluting stents: synchronous with late stent thrombosis?

Initial approval of drug-eluting stents (DES) was based on randomised, controlled trials that demonstrated a significantly greater reduction in the rates of target-vessel failure and risk of repeated revascularisation, or both, compared with bare-metal stents (BMS), at 9 months. Despite the beneficial effects of DES demonstrated in these early and pivotal studies, the trials were individually not adequately powered to detect differences in the rates of death, myocardial infarction (MI), or stent thrombosis. As a condition of approval, the US FDA, recognising the need for longer-term data on the devices, required the manufacturers to follow patients in their original clinical trials for 5 years after implantation, and to conduct registry studies of consecutively enrolled new patients to evaluate the potential for less frequent adverse events. Long-term data are now available, and can be pooled to conduct analyses with greater power than those in the original trials. In light of the recent concern that the use of DES may be associated with a small increased risk of late stent thrombosis, compared with BMS, the NEJM has published five recent studies investigating their safety.