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This Is A Sample
Letter That Is Sent To Physicians That Are Involved In The Care Of
Our Patients That Have Received A Drug-Eluting Stent In The Past.
Re: Discontinuation of Plavix (Clopidogrel); in patients
that have received a “drug-eluting” stent (includes the JJIS/Cordis
Cypher stent, and the Boston Scientific/Sci-Med Taxus stent)
Dear Doctor:
Your patient underwent implantation of a “drug-eluting” coronary
stent as part of his/her revascularization procedure. Coronary
stents require the oral administration of combination anti-platelet
agents (aspirin and clopidogrel) for a prolonged period of time
after implantation, to avoid the development of stent thrombosis
(ST). Such an event can be associated with a large myocardial
infarction, and even death (related to sudden epicardial coronary
occlusion). With all stents [“non-drug-eluting” (bare-metal) stents
(BMS), and “drug-eluting” stents (DES)], the greatest risk occurs
within the first 10-days after implantation (before the stent has
become endotheilialized). The risk of ST immediately after the
initial implant is ~ 1% in patients on combination anti-platelet
therapy, but much greater without the combined anti-platelet
protection. It has been generally accepted that most patients will
endothelialize BMS within a few weeks after implant, and the
critical time to maintain dual anti-platelet therapy in these
individuals will be for at-least the first month after implantation.
The PCI-CURE study (Lancet: 358; August 2001) determined that
there was a lower incidence of death, myocardial infarction, and
repeat revascularization in individuals that had continued their
combination anti-platelet therapy for 1year post-stent implantation
(as compared to those that received conventional combination
anti-platelet therapy for only one month).
DES are the newest type of coronary stents, and have been implanted
in more than 4 million individuals worldwide beginning with their
introduction in 2003 up until the end of 2006. During this time, a
DES was used in > 80% of patients. DES have shown the ability to
decrease coronary target-lesion revascularization by > 50% (by
reducing the overall restenosis rate to <3%) as compared to BMS. The
long-term major adverse cardiac event rate with the use of a DES
remains < 5% overall (includes the incidence of death, myocardial
infarction, and repeat revascularization). DES have proven to be
superior to BMS in specific lesion-types (chronic total occlusions,
in-stent restenosis, aorto-ostial lesions, saphenous vein grafts,
bifurcation lesions, and multi-vessel disease). Reports have
surfaced regarding the development of very late ST at >1 year after
stent implantation in a small number of individuals (incidence of
~0.5% to 0.6% per year in patients with DES). In many of these cases
reported, the events occurred after the stented individuals had
discontinued their combination anti-platelet therapy.
The CHARISMA trial, presented at the American College of
Cardiology’s Annual Scientific Session in March 2006, and published
in the New England Journal of Medicine reported an increase in the
incidence of “moderate bleeding” in individuals taking both aspirin
and clopidogrel [1.7%] (as compared to individuals taking only
aspirin [1.3%]). This study included individuals without coronary
stents, who were taking the medications for other indications (heart
attack, stroke, etc.) Shortly after the release of this trial, the
American College of Cardiology issued a reminder to its member
cardiologists, that according to the 2006 ACC/AHA/SCAI Guidelines of
Percutaneous Coronary Intervention: “the use of aspirin and
clopidogrel in patients undergoing angioplasty with stent
implantation remains a class I recommendation.” The long-term use of
aspirin and clopidogrel in patients that have received DE S is a
class IIb recommendation.
The exact mechanism by which a nidus for ST develops after DES
implantation is not definitively known. Some subscribe to the theory
of delayed healing with incomplete endothelialization and persistent
stent strut exposure to the circulation. Other possible explanations
include: an abnormal healing response – possibly with partial
retraction of the vessel wall away from the stent, and possibly some
form of a hypersensitivity reaction to the stent material or
coating. The risk of ST is substantially increased in individuals
that discontinue their dual antiplatelet therapy. In any event, the
interventional cardiology community has been encouraged by the
authorities to communicate the status and extent of the problem to
the other physicians involved in these patients’ care.
If you believe that it may be necessary to discontinue Plavix
(clopidogrel) in this patient: Please contact our office
immediately, so that we may discuss the matter with you in more
detail. Please also be aware that a growing number of surgeons are
becoming aware of the issues with “drug-eluting” stents. Many are
willing to perform surgical procedures on these patients while
maintaining their dual anti-platelet therapy, particularly where the
risk of surgical bleeding related to a specific procedure may be
relatively lower. We encourage you to consider this option to help
afford our patients optimal cardiac protection. In all situations,
the risk of procedural or peri-procedural bleeding in patients on
aspirin and clopidogrel must be weighed against the risk of stent
thrombosis encountered after the discontinuation of these
medications.
Thank you for your time and attention to this matter. Please feel
free to contact us for any additional information that you may
require. |
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