Wednesday, September 13, 2006

DES, More Bad News

Cardiologist from across the world over are presently meeting in Barcelona, where the European Society of Cardiology and the World Federation of Cardiology are having a combined congress. The first day of meeting was yesterday. Interventional cardiology, and in particular DES took center stage. The morning had two papers on the incidence and causes of late stent thrombosis, from Netherlands and Switzerland. The bad news is yet to come.

In the evening, as the Spanish sun was setting, two papers out of Switzerland, both meta-analysis, revealed what we feared most. That DES (in this case the cypher and taxus stents), had a increase incidenced of death, as we followed patients over 3-4 years. The research were not initiated by the makers of the stents. Of course JnJ Cordis and Boston Scientific, the makers of Cypher and Taxus, deny the conclusion of the meta-analysis. They carried out their own analysis, and did not see the trend. It is important to note that the authors of the two Swiss study, compared many of the large scale clinical trials of the two stents. It is only fair to say the it was the Cypher stents that was largely the culprit. One of the studies showed that the rising trends of mortality was mainly cardiac, due to late stent thrombosis, as indicated by the earlier late-basket trial. The second Swiss study indicated the the rising mortality could be non-cardiac, due to increase incidence of lung disease, cancers, and strokes, when compared to bare metal stents.

This is very worrying. As we all know, bare metal stents has been in used for the last twenty years, and there is no trend of increasing mortality. Bare metal stents don't kill. They have a higher incidence of restenosis, and we all know that restenosis may require another procedure, but restenosis does not kill. So, when we see rising trends of mortality with DES, all the red-flags are out. I am at a loss as to how we can explain rising cancer and stroke rates. Is the sirolimus doses, though small, adequate to stimulate some form of immune response which affected the apoptotic process of cells. I don't know, but I am surely very worried now. Late stent thrombosis is bad enough. The hint of rising cancer rates (if indeed it is true), is certainly very very alarming. Well the Barcelona meeting has just started. I wonder what else is in store for us over the next three days.

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