Saturday, September 04, 2010


One of the more interesting presentation from the just concluded ESC 2010, Stockholm, is lesson 1. As we all know, interventional cardiology has advanced by leaps and bounds. I must say that the transition from bare metal stent to DES ( drug eluting stents ) at the turn of the century, is revolutionary. As a result, the DES stent market is now very competitive and each stent is trying to outdo the other in marketing, so that they can increase their market share.
On the clinical end, we have ( as physicians ) seen the evoulution of the first generation DES ( Cypher and Taxus ) to the second generation DES ( Endeavor, Xience V, Promus, and maybe biomatrix ), and in the horizon, we see the third generation undergoing intense clinical study, and waiting to burst into the market.
Yesterday, I received a text message from a stent company staff telling me that their DES has outdone the benchmark first generation Cypher, in the latest clinical trial, just presented at ESC 2010 at Stockholm. The clinical trial is called LESSON 1. So I decided to look into it. The market earlier had told me that the result is borderline, even before the presentation. ( We always have corridor talks and hunches. I must say that in my experience, hunches have more often been right then wrong ). Anyway ..............
LESSON 1, is a clinical trial led by Dr Stephen Windecker, a prominent interventionist from the University of Bern Hospital. He studied 1342 matched pairs of patients. Half of them had cypher implanted, in the early years, with 3 year follow-up, and then matched them with the next half who had Xience V implanted. They were propensity matched, and followed up. The primary end point was death, MI and TVR ( target vessel revascularisation or restenosis for the laymen ).
Well, the corridor talk is correct. If you take the primary end point, the P value is 0.056 ( near but not yet significant ). If you massage the results a little and do some unbundling and cheery picking, you will find that the Xience V stent, did do a little better in terms of less stent thrombosis in the early years and also less target vessel revascularisation.
The long and short is that from LESSON 1. we learn take the second generation DES is a little better then the first generation -limus DES. We know that. That is why we called them second generation improvements.
But, in my opinion, LESSON 1 was not a very fair trial. From the first group of patients to the second group of patients, interventionist have become wiser as to when, how and how to implant DES better. The technical aspects have improved overtime. We also began to understand stent thrombosis better ( especially after 2006 Barcelona when we faced the stent thrombosis storm ). We then became more obsess with dual anti-platelet therapy, and the importance of continuing.
It is of course true that the Xience V DES is physically better, having learned the lesson from cypher as to how not to have too thick a polymer coating and also what dose of everolimus is optimal. Of course the Xience V stent is of much thinner strut and much easier to deploy.
Basically, what I am trying to say is that LESSON 1 did not tell us what we did not know. It confirmed what we knew all along, when Xience V was launched. Xience V is technically a better stent, and the Cypher stent is one generation earlier. That also means that we have better knowledge of cypher's long term behaviour. As I always tell my patients, a stent implanted is permanently there in your body. Long term results about their good and bad effects are very important. In business, you call it track record. The cypher stent has a longer track record ( a track record of about 10 years ). The Xience V track record is half that.
Xience V may be technically a better stent, but how will it perform in 10 years, only time will tell. Cypher has that record already.
There is no easy answer. That is what makes interventional cardiology and medicine, so interesting. The debate goes on.

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