< International Circulation >: Could you talk about recent progress for detection of vulnerable plaques?

Prof. Gary S. Mintz: There has not been a lot of progress for detection of vulnerable plaques， but， there are many techniques that are being developed. In the last year， maybe the techniques have got- ten a little better， but there have been a few more studies that have to be done.Probably the single most important study is PROSPECT in Rome. We have completed the baseline analysis in PROSPECT， and I believe we have reached the endpoint in terms of 100 events in patients for PROSPECT. So at least we have a group of 700 patients who may have data to be analyzed， which probably will tell us several things. First of all， it will tell us how common are the vulnerable plaques related to events in patients after PCI: that is something we still do not know. Secondly， it will show how often those events are either true vulnerable plaque events or often lesions that should have been treated during the initial PCI. And thirdly it will allow us to look at true technology， especially virtual histology and palpography， to see if either technology can predict the vulnerable plaque event.
The other technologies have incremental steps in terms of validation， optical coherence tomography which can provide basic imaging will quickly give way in the next year to the next generation optical imaging， called OFDI， which will be much more user-friendly， but there is no real additional data on that technique involving plaque. Other techniques， such as magnetic resonance imaging， have completely additional validation studies， but， these are not clinical studies. Hence we have made small incremental progress， but we certainly not have made a lot of progress in the last year.

< International Circulation >:  How do you evaluate the safety of the DES?

Prof. Gary S. Mintz:  Let’s go over the history of the DES. Everybody was very enthusiastic about drug-eluting stents until roughly two years ago， when report from the European Society of Cardiology suggested that drug eluting stents were associated with more mortality. It turns out that， first of all， those studies were in fact incorrect. The data was presented prematurely and incompletely analyzed. And approximately one year later in TCT in last October， study after study showed that drug eluting stents were at least as safe as， or perhaps safer than bare metal stents. 

What we do recognize is the following: That for drug-eluting stents， there is a very small but increased risk in very late thrombosis beyond the year that is not seen in bare metal stents. However， what people have to understand is that when bare metal stents have restenosis and patients come to hospital for additional procedures to treat restenosis， each of those procedures is also associated with a small risk， including the risk of death. So the two issues balance each other. Drug eluting stents have a slight， fairly small increase risk of very late thrombosis， while bare metal stents are requiring multiple repeated procedures overtime， also have an increase risk of complications because of all those additional management procedures. 

What we do know about drug-eluting stents is that they also required anti-platelet therapy for one year or even longer in some cases to prevent the risk of complications， such as very late thrombosis related to the complexity of lesions. If the patients can’t take anti-platelet therapy， they should not have drug-eluting stents， say， a patient who needs a cancer surgery in the next few months， because clopidogrel has to be stopped.