Author + information
- Peter B Berger, MD,
- Stephanie H Wilson, MB, BS, FRACP,
- Panayotis Fasseas, MD and
- James L Orford, MBChB, MPH ()
We thank Dr. Auer and colleagues for raising an important issue. All patients in our study were enrolled between 1990 and 2000, before drug-eluting stents (DESs) were available. Therefore, the results of our study and any conclusions they permit should only be applied to bare stents, and we explicitly stated that they should not be applied to situations in which re-endothelialization is delayed, such as brachytherapy.
Little is known about how patients ought to be managed prior to noncardiac surgery in the DES era, an issue that has already arisen many times at the Mayo Clinic. The answer may differ depending on which DES is being considered (1). The two studies cited, revealing that use of DESs delays endothelialization, were both of paclitaxel-eluting stents, but the polymer, release mechanisms, stent design, and, in the Farb study, the animal model (rabbits) were too different to extrapolate to the TAXUS program. With the slow-release formulation on the paclitaxel stent being commercialized, approximately 10% of the paclitaxel is released by 10 days, whereas the remaining 90% remains in the polymer indefinitely. The clinical significance of this is unclear. In contrast, sirolimus has nearly entirely eluted from a Cypher stent within 30 to 45 days, essentially leaving a polymer-coated bare metal stent. Animal models suggest that the sirolimus stent may not delay re-endothelialization (2,3)but that the paclitaxel stent does (Dr. R. S. Schwartz, personal communication, January 12, 2004).
However, based on the design of the pivotal clinical trials leading to approval of these stents (and not on what is known about the rate of re-endothelialization in humans), clopidogrel is recommended for two to three months following placement of a sirolimus-eluting stent and for six months following placement of a paclitaxel-eluting stent. Accordingly, until the clinical outcomes of large numbers of patients who received a DES and who did not complete their assigned course of clopidogrel are analyzed, we recommend the following. If a patient requires noncardiac surgery within two months of percutaneous coronary intervention (PCI), and the type of surgery (or surgeon) will not permit continuing aspirin and clopidogrel throughout the perioperative period, we suggest a DES not be used (although it is possible that a sirolimus-eluting stent might be safe in this setting); we recommend a non-DES stent, perhaps one that might possibly reduce thrombosis without clopidogrel on-board during the prothrombotic state of surgery, such as a heparin-coated or phosphorylcholine-coated stent (though it must be emphasized that it is entirely unproven that such stents do indeed reduce stent thrombosis in humans, let alone following noncardiac surgery). It is also possible that balloon angioplasty alone is a reasonable option for certain lesion types and clinical situations prior to noncardiac surgery if a satisfactory result can be achieved.
We also thank Dr. Mendoza and colleagues for their interest in our study. We agree that our investigation was severely limited in its ability to detect the relationship between the concomitant antiplatelet therapy administered following preoperative PCI, time to surgery, and perioperative bleeding; undoubtedly such a relationship exists. Our study does not, however, demonstrate, or even address, whether preoperative PCI increases adverse perioperative cardiac events. Preoperative PCI was performed in most patients included in our study in an attempt to reduce such events, although we agree that data are lacking whether it actually does so. We support the call by Mendoza and colleagues for large prospective studies of this issue; fortunately, several are underway. In the meantime, the choice of either stent (bare metal vs. drug eluting) or reliance on balloon angioplasty without stent placement is an important consideration for the interventionalist performing revascularization on high-risk patients who might possibly benefit from revascularization before undergoing high-risk surgery. We are of the opinion, however, that most patients with coronary disease in whom noncardiac surgery is planned do not require preoperative revascularization. In general, the indications for revascularization before noncardiac surgery are the same as in patients in whom surgery is not planned, and it is rare to need to revascularize a patient just “to get them through surgery.” (4)
- American College of Cardiology Foundation
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- ↵Schwartz, RS, Wilson G, Seifert P, et al. Paclitaxel-eluting stents: escalating dose effects in a porcine coronary model. Submitted