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Preoperative Evaluation/Patient Issues/Patients with recent cardiac stents

QUESTION:

I am the medical director of Canyon Surgery Center in Phoenix, AZ. During a recent State inspection we were told that a death had occurred in a patient with a stent in a local outpatient facility. They felt that we needed to formulate a policy for when patients post insertion of a coronary stent are candidates for outpatient surgery. I have been searching the cardiology literature only to find that the cardiologist do not agree with any specific time recommendation. Their literature says anything from ok to do in first 2 weeks after insertion of stent, but not ok after 8 weeks, to should wait 4-6 weeks for anticoagulant therapy, and one paper noted a 30% restenosis rate within the first 6 months.

I have asked several other medical directors in my area and we have all come up against the same problem of no real answer in the literature. I even contacted the American College of Cardiology who referred me to an article which didn't give a concrete answer either. In that article they basically took the position that cardiac clearance consists of "optimizing the patient", but didn't give any real guidelines either. I also contacted the ASA and was given the following response from Karen Williams, M.D., Chair of the Committee on Surgical Anesthesia:

"Your question regarding the timing of performing elective surgery following the recent placement of coronary stents was referred to me as Chair of ASA's Committee on Surgical Anesthesia. Your question was circulated to committee members who all agree with your research on the matter. The current literature is controversial regarding the timing of elective surgery after stenting. There are no prospective, definitive studies. Empirically, some institutions wait until the antiplatelet therapy is maximized, others wait for 4 weeks up to 12 months for some types of stents if there is a high restenosis rate within the first few months. It seems that your policy would be based on the multidisciplinary input with your cardiologists, based on your best judgment."

So, I am very interested to see if some sort of consensus can be reached and a standardized time agreed upon.

-- From Rebecca Dalmeida, M.D., Phoenix, AZ.

REPLY:

Cardiologists have added coronary stents to balloon angioplasty because they prolong patency. However, the downside is an early (~1 st three months) increase in stent thrombosis compared to angioplasty alone. For this reason, cardiologists employ aggressive antiplatelet therapy in the short-term (weeks to months) after stent placement.

Obviously, we would prefer not to anesthetize a patient in the midst of stent thrombosis, or just before, especially since hypercoagulability often follows surgery. On the other hand, surgery performed on a patient receiving aggressive antiplatelet therapy may increase bleeding. In the 2002 revision of AHA/ACC Guidelines for Perioperative Cardiovascular Evaluation For Noncardiac Surgery (Eagle KA et al. Circulation. 2002;105:1257-67), the following was recommended:

“There is uncertainty regarding how much time should pass between PCI (percutaneous coronary intervention) and noncardiac procedures. Delaying surgery for at least 1 week after balloon angioplasty to allow for healing of the vessel injury has theoretical benefits. If a coronary stent is used, a delay of at least 2 weeks and ideally 4 to 6 weeks should occur before noncardiac surgery to allow 4 full weeks of dual antiplatelet therapy and re-endothelialization of the stent to be completed, or nearly so.”

While several studies suggest that most patients who have had a stent do well, others suggest that surgery in the 6 weeks after stent placement may be associated with catastrophic events (Kaluza GL et al. J Am Coll Cardiol. 2000;35:1288-94). These include stent thrombosis if the antiplatelet therapy is stopped, and hemorrhagic complications if therapy is continued. However, this cohort of patients underwent major vascular surgery; the relevance to smaller out-patient procedures in unclear.

My recommendation, acknowledging a rapidly changing field and the absence of clear guidelines, is that elective surgery be postponed until at least 4 weeks of antiplatelet therapy are completed, followed by 1 week off of antiplatelet therapy. In some cases (especially carotid endarterectomy, cerebrovascular disease) cardiologists and/or surgeons may wish to continue therapy until the time of surgery, with the attendant bleeding risks. For patients who have an “old” stent (placed more than 2-3 years in the past), preoperative stress testing and/or cardiology consultation may be warranted if there are significant risk factors, symptoms, or exercise limitation because stents (and certainly angioplasty) are less durable revascularization than CABG.

-- From John E. Ellis, M.D., Chicago, IL

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