Should we stop aspirin before noncardiac surgery?

PATIENTS WITH CORONARY STENTS UNDERGOING NONCARDIAC SURGERY

Percutaneous coronary intervention (PCI) accounts for 3.6% of all operating-room procedures in the United States,¹⁵ and 20% to 35% of patients who undergo PCI undergo noncardiac surgery within 2 years of stent implantation.^16,17

Antiplatelet therapy is discontinued in about 20% of patients with previous PCI who undergo noncardiac surgery.¹⁸

Observational data have shown that stopping antiplatelet therapy in patients with previous PCI with stent placement who undergo noncardiac surgery is the single most important predictor of stent thrombosis and death.^19–21 The risk increases if the interval between stent implantation and surgery is shorter, especially within 180 days.^16,17 Patients who have stent thrombosis are at significantly higher risk of death.

Graham et al⁴ conducted a subgroup analysis of the POISE 2 trial comparing aspirin and placebo in 470 patients who had undergone PCI (427 had stent placement, and the rest had angioplasty or an unspecified type of PCI); 234 patients received aspirin and 236 placebo. The median time from stent implantation to surgery was 5.3 years.

Of the patients in the aspirin arm, 14 (6%) had the primary outcome of death or nonfatal MI compared with 27 patients (11.5%) in the placebo arm (absolute risk reduction 5.5%, 95% CI 0.4%–10.5%). The result, which differed from that in the primary trial,¹ was due to reduction in MI in the PCI subgroup on aspirin. PCI patients who were on aspirin did not have increased bleeding risk. This subgroup analysis, albeit small and limited, suggests that continuing low-dose aspirin in patients with previous PCI, irrespective of the type of stent or the time from stent implantations, minimizes the risk of perioperative MI.

GUIDELINES AND RECOMMENDATIONS

Routine perioperative use of aspirin increases the risk of bleeding without a reduction in ischemic events.¹ Patients with prior PCI are at increased risk of acute stent thrombosis when antiplatelet medications are discontinued.^20,21 Available data, although limited, support continuing low-dose aspirin without interruption in the perioperative period in PCI patients,⁴ as do the guidelines from the American College of Cardiology.⁵

We propose a management algorithm for patients undergoing noncardiac surgery on antiplatelet therapy that takes into consideration whether the surgery is urgent, elective, or time-sensitive (Figure 1). It is imperative to involve the cardiologist, surgeon, anesthesiologist, and the patient in the decision-making process.

In the perioperative setting for patients undergoing noncardiac surgery:

• Discontinue aspirin in patients without coronary heart disease, as bleeding risk outweighs benefit.
• Consider aspirin in patients at high risk for a major adverse cardiac event if benefits outweigh risk.
• Continue low-dose aspirin without interruption in patients with a coronary stent, irrespective of the type of stent.
• If a patient has had PCI with stent placement but is not currently on aspirin, talk with the patient and the treating cardiologist to find out why, and initiate aspirin if no contraindications exist.