Friday, August 24, 2012


One of the on-going dilemmas in coronary intervention is the issue of non cardiac surgery post coronary stenting. The coronary disease population is also that same population that is more likely to develop cancers, prostate problems, knee and hip problems and gallbladder disease. many of these conditions may require surgery. Some of these surgeries may be emergent, urgent non-emergent, or elective.I suppose, in the issue of emergency surgery, the decision to save live is obvious and the surgery will have to be done, including discontinuing the dual anti-platelet therapy ( and the 4% risk of acute stent thrombosis with a DES ).
As we understand it, stents have a metallic plateform, be it bare metal stents ( obviously ) or drug eluting stents ( DES ), where the metal is coated with a polymer ( or in some case, no polymer or bio-erodable polymer ). Metals attract platelets and so blood clots ( stent thrombosis ). However, over time, the normal body response to injury will cause scar tissue to form, and line the metallic platform. Over-exuberant scar tissue healing is the cause of stent re-stenosis. Drug eluting stents was our answer to delay and limit over-exuberant scar healing formation. So tissues heal slower with drug eluting stents, and so the metal is expose for longer and so more prone to clots / thrombus for longer.
That brings us to the point of how safe is it to stop dual anti-platelet therapy should a patient need non-cardiac surgery? The clinical guidelines given by most professional bodies, seemed to be one year at least ( basing mainly on the first generation DES like cypher and taxus ). However, recent literature seemed to suggest that with the newer, second generation DES like Endeavor and Xience V, the drug and drug elution characteristics are so good, that they are able to allow limited tissue healing faster, without re-stenosis, and yet without stent thrombosis ( the finer point of DES ).
So, there is a paper out in the Aug 14th 2012, issue of Circulation by the group from Toronto, led by Dr Dennis Ko, studying this issue. Dr Ko and group studied 8116 patients who ha stents ) nad also DES ( Drug eluting stents ), who had to undergo non-cardiac surgery. After 2 years of follow-up, they found that stopping dual anti-platelet  therapy ( DAPT ) after 45 days for BMS and after 6 months for DES was safe, with no increase MACE.
This is important for us, as the guidelines states that it should be one year for DES and 1 month for BMS.
Currently in my practice, after the Resolute All-Comers trial results, I have kept my patients on DAPT for 6 months when I use the Endeavor Resolute or Xience V. I think that 6 months is adequate. For BMS, it is even easier, 2-4 weeks will do.
So far, so good. It has worked quite well for me and my patients.

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