Stent thrombosis (ST) is an event which may lead to myocardial infarction (MI) or death. The recognition of ST demands the demonstration of thrombus in the stented segment. When MI or death occurs in close temporal relationship with stenting, usually within 1 month, we accept any of these adverse events as indirect support for the occurrence of ST. During an extended follow-up interval, the relationship between ST and the occurrence of MI or death becomes less clear. It is obvious that multiple factors may lead to MI or death, besides ST, and the chances that any of these factors will come into play increase with the length of follow-up. The natural conclusion is that the possibility of making a firm identification of ST occurring months or years after stenting decreases if we only rely on the occurrence of MI or death. This foreword is important because put into perspective, the end point of late ST becomes unreliable unless demonstrated by angiography or autopsy. For the report by Hoffman et al presented in this issue of Heart (see article on page 10.1136/hrt.2007.120154),1 the event of ST required angiographic documentation.

LATE INCOMPLETE STENT APPOSITION

Incomplete stent apposition (ISA) or stent malapposition is the intravascular ultrasound (IVUS) finding of lack of contact between stent struts, not overlying a side branch, and the underlying arterial wall. Late ISA may be due either to persistence of acute ISA occurring at the time of stent implantation or late-acquired ISA occurring between stent implantation and follow-up. Traditionally the term “late ISA” has mainly been used to describe late-acquired ISA. Late ISA (acquired) was well recognised after bare-metal stent (BMS) implantation. The predictors for the occurrence of late ISA after BMS implantation were directional coronary atherectomy before stenting and stenting performed in a setting of acute MI.2 Studies have …