Coronary Artery Stent Placement Immediately before Noncardiac Surgery: A Potential Risk?

Percutaneous coronary intervention (PCI), angioplasty with stenting, is commonly used for treatment of symptomatic coronary artery disease. The introduction of stents has reduced the incidence of restenosis, one of the major drawbacks of coronary angioplasty, and has proved to be an alternative treatment for bypass surgery. This strategy may be attractive compared with bypass surgery in patients scheduled to undergo general surgery, because the delay of the index surgical procedure is prevented. However, initially, stent placement causes complete denudation of the arterial endothelial surface, and stent struts may damage the media or penetrate into the lipid core, inducing inflammatory and coagulation activity. These factors temporarily increase the risk of in-stent thrombosis until a neointima has been formed. Fortunately, the introduction of dual antiplatelet therapy (aspirin and clopidogrel) has overcome this complication and reduced the rate of in-stent thrombosis to less than 1%.

However, recent stent placement might be potentially harmful for patients undergoing noncardiac surgery. Surgery increases the thrombosis risk due to a perioperative stress response including sympathetic activation promoting sheer stress on arterial plaques, enhanced vascular reactivity conducive to vasospasm, reduced fibrinolytic activity, platelet activation, and hypercoagulability. In addition, while the surgical patient is in a hypercoagulable state, dual antiplatelet therapy is often interrupted because of the fear for excessive bleeding complications during surgery.

This double-edged sword of coronary stenting and prevention of cardiac complications on one hand and an excess of bleeding risk on the other remains a controversial issue in perioperative management. Therefore, we have reviewed the currently available evidence on stent-related complications in the perioperative period in which timing of surgery and antiplatelet strategy seems to play a pivotal role.

A systematic electronic search of published reports on Medline was undertaken to identify studies published between January 1995 and October 2006 in English language that reported on perioperative cardiac outcome after noncardiac surgery in patients with a history of PCI with stenting. To identify eligible studies, the following Medical Subject Heading terms, or a combination of these, were used: stent , myocardial revascularization , surgery , postoperative complications , mortality , myocardial infarction, and perioperative care . Furthermore, we examined the reference lists of identified articles and published recommendations for perioperative cardiac risk management. Eventually, a total of 10 relevant studies were identified.1–10Pertinent data from the selected studies were extracted independently by two investigators.

The 10 studies encompass a total of 980 patients who underwent noncardiac surgery after coronary stent placement. The median time from PCI to noncardiac surgery ranged from 13 to 284 days. The majority of reports included bare metal stent use, and only 2 recent studies reported the outcome of drug-eluting stents.8,10Perioperative myocardial infarction and death were common complications, with myocardial infarction rates ranging from 2% to 28% and death ranging from 3% to 20% (fig. 1). Studies with a short median interval between PCI and noncardiac surgery reported higher cardiac complication rates as compared with reports with a longer median time interval. Importantly, when studies with a longer median interval between PCI and noncardiac surgery were evaluated in more detail, patients with early surgery experienced more cardiac events than those with late surgery (table 1). Discontinuation of antiplatelet therapy is an important factor in this respect. Unfortunately, not all studies provided data on the number of patients that stopped antiplatelet therapy before surgery. However, if data were available, there was a clear trend toward a higher incidence of perioperative events after stopping antiplatelet therapy. In the report of Kaluza et al. ,16 of 8 patients who died in the perioperative period were without antiplatelet therapy. The same trend was found by Sharma et al.  3; 86% of patients who discontinued antiplatelet therapy died perioperatively versus  only 5% in the group of patients who continued antiplatelet therapy. Recently, we confirmed this finding in a study of 192 patients. In particular, in patients with early noncardiac surgery, there was a marked difference in major adverse cardiac events (30% vs.  0%, respectively, for patients who stopped and continued antiplatelet therapy).10 

The minimal period in which antiplatelet therapy should be prescribed before noncardiac surgery is ill-defined. A period of 4 weeks seems to be too short, as shown by the study of Brichon et al.  5In a group of 20 patients, 2 experienced perioperative in-stent thrombosis, suggesting that a prolonged period of antiplatelet therapy may be required. A period of 6 weeks is supported by the results of the studies of Wilson et al.  4and Reddy et al.  2In a group of 79 patients undergoing noncardiac surgery after an interval of 6 weeks, no major cardiac events occurred. These results were questioned by the study of Vicenzi et al.  7In 56 patients who underwent noncardiac surgery more than 90 days after PCI, the cardiac event rate was as high as 34% within 3 months after surgery.7However, it should be taken into account that in a number of patients, antiplatelet therapy was stopped 3 days before noncardiac surgery, which may be related to adverse outcome. Ferrari et al.  11showed that stopping antiplatelet therapy, even after a long period since stenting (mean time between stenting and withdrawal 15.5 ± 6.5 months), was a significant risk factor for adverse cardiac events.

In conclusion, the current available literature suggests that noncardiac surgery after PCI with stenting should be delayed at least 6 weeks, and dual antiplatelet therapy is associated with improved outcome.

*Erasmus Medical Center, Rotterdam, The Netherlands. d.poldermans@erasmusmc.nl