By Michael H. Crawford, MD, Editor
Synopsis: A larger randomized controlled trial of aspirin monotherapy vs. no antiplatelet therapy in patients more than one year post-drug-eluting coronary stent placement failed to show a difference in ischemic outcomes or major bleeding, but minor bleeding was more common in the aspirin group.
Source: Kang KY, Lee SH, Lee SW, et al. Aspirin monotherapy vs no antiplatelet therapy in stable patients with coronary stents undergoing low-to-intermediate risk noncardiac surgery. J Am Coll Cardiol. 2024;84(24):2380-2389.
Few data are available on the management of antiplatelet therapy in patients with the second- and third-generation drug-eluting stents (DES). Thus, the aspirin in patients with DES undergoing noncardiac surgery (ASSURE-DES) trial is of interest.
This is a multicenter, open-label, randomized controlled trial conducted at 30 sites in Korea, India, and Turkey. It enrolled adults who were more than one year post-DES placement (one or more) who were scheduled for elective noncardiac surgery. Excluded were patients who were within a month of an acute coronary syndrome, or who had an ejection fraction < 30%, valvular heart disease, need for oral anticoagulation, emergency surgery, or very high bleeding risk surgery (eye, brain, spine).
Eligible patients were randomized to aspirin 100 mg monotherapy or no antiplatelet therapy five days before surgery. Aspirin or other antiplatelet therapy was resumed by 48 hours post-surgery unless significant bleeding was occurring. The primary outcome was a composite of all-cause mortality, myocardial infarction (MI), stroke, or stent thrombosis within 30 days. The safety endpoint was major or minor bleeding.
The investigators based their patient population size on an expected 6% to 12% incidence of the primary endpoint. Between 2017 and 2024, a total of 926 patients were randomized: mean age 69 years, 24% women, 45% with diabetes. The surgery was abdominal in 40% of patients, orthopedic in 23% of patients, and urologic-gynecologic in 19% of patients. Most surgeries were low- to moderate-risk. The median time between DES and the surgery was five years. Most patients had second-generation DES or greater.
The primary outcome occurred in three patients (0.6%) in the aspirin group and four patients (0.9%) in the no antiplatelet therapy group (P = NS). The overall rate of MI was 0.6% in both groups, but two patients had fatal MIs in the aspirin group. A subgroup of 283 patients had serial troponins measured, and post-operative elevated values were detected in 23% of the aspirin group and 20% of the no antiplatelet therapy group (P = NS). There were no stent thromboses. Major bleeding was not different between the two groups (6.5% vs. 5.2%, P = NS), but minor bleeding was more common in the aspirin group (15% vs. 10%, P = 0.027).
The authors concluded that there was no significant difference in the composite primary endpoint or major bleeding at 30 days post-noncardiac surgery in patients with a DES placed more than year prior undergoing elective noncardiac surgery and randomized to aspirin monotherapy vs. no antiplatelet therapy.
Commentary
Current guidelines recommend continuing aspirin monotherapy in patients more than one year post-DES undergoing elective noncardiac surgery (class I-B). However, this recommendation is based on observational studies mainly in patients with first-generation DES or bare metal stents. Since these studies were performed, there have been significant advances in stent construction and deployment that have minimized stent thrombosis. Also, there have been advances in surgery allowing less invasive and shorter surgeries. Thus, it may not be necessary to withhold all antiplatelet drugs prior to noncardiac surgery in patients with DES.
There are limitations to ASSURE-DES that should be considered. The major limitation of the study is that the adverse event rate was way below what was predicted and, thus, the population may have been too small to detect a difference in outcomes. This is perhaps because most of the patients were East Asian, who some believe are at lower risk of ischemic complications. Also, most patients had low- to intermediate-risk surgeries and there were very few with higher-risk surgeries (such as vascular). In addition, all were stable patients undergoing elective surgeries and only a subgroup (31%) had troponin measured.
Finally, there were relatively few patients included who were one to two years out from DES placement and may be at a higher risk of stent thrombosis. On the other hand, the researchers stopped antiplatelet therapy five days before surgery, whereas others recommend stopping seven days before surgery. This may have disadvantaged the no-antiplatelet group.
Despite these limitations, I believe this study opens the door to a more nuanced approach to antiplatelet therapy with elective low- to intermediate-risk noncardiac surgery for patients who had DES placement more than a year ago. In low-risk situations, the increased minor bleeding with aspirin, which may prolong hospital stay and diminish the patient’s experience, could be avoidable with deciding not to continue aspirin during surgery in selected patients.
Michael H. Crawford, MD, is Professor of Medicine and Consulting Cardiologist, University of California Health, San Francisco.
A larger randomized controlled trial of aspirin monotherapy vs. no antiplatelet therapy in patients more than one year post-drug-eluting coronary stent placement failed to show a difference in ischemic outcomes or major bleeding, but minor bleeding was more common in the aspirin group.
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