Key Points:
- Anti-platelet therapy after coronary drug eluting stent (DES) placement reduces the risk of future ischemic events, but the risk of in-stent thrombosis with temporary interruption of anti-platelets decreases over time.
- Holding aspirin for non-cardiac surgery more than one year after DES placement could lower peri-operative bleeding risk, but whether this is outweighed by the ischemic risk remains uncertain.
- ASSURE DES randomized patients with prior DES undergoing non-cardiac surgery to continuation or interruption of aspirin, and found no difference in major ischemic or bleeding events, but the lower than expected event rates left the study underpowered.
Current ESC guidelines recommend that patients with a history of percutaneous coronary intervention who subsequently require non-cardiac surgery continue aspirin monotherapy through their procedure.1 However, the evidence supporting this recommendation is based on a non-prespecified subgroup analysis of an older trial with a small sample size; more than half of participants had a bare metal stent.2
On August 31st 2024, the principal results of the “ASSURE DES: Perioperative antiplatelet therapy in patients with coronary stents before non-cardiac surgery” was presented at ESC Congress 2024. The purpose of this study was to determine whether temporarily holding aspirin for non-cardiac surgery among patients at least one year after DES reduces bleeding without increasing the risk of ischemia.
The open-label trial included 926 patients in South Korea, India, and Turkey who had undergone DES implantation more than one year prior to an elective non-cardiac surgery. They were randomized in a 1:1 fashion to either continue aspirin or discontinue all antiplatelet agents 5 day prior to their procedure with recommendations to resume no later than 48 hours post-procedure, unless contraindicated. The primary outcome was a composite of all cause death, myocardial infarction (MI), stent thrombosis, or stroke within 5 days before surgery to 30 days after surgery. Secondary outcomes included TIMI major or minor bleeding events.
The average age was 68.5 years; 24% were female. Nearly 90% of the surgeries were categorized as low-to-intermediate bleeding and ischemic risk. At randomization, 39% were on aspirin monotherapy, 34% were on dual-antiplatelet therapy, and 23% were on P2Y12 inhibitor monotherapy. The average time from DES to surgery was 6.3 years, and 84% had a second generation or later DES.
At 30 days, primary event rates were low. There were 3 MIs and 1 stroke in the interruption group (0.6%), and 2 cardiac deaths and 3 MI in the continuation group (0.9%), for a non-significant difference of 0.2 percentage points (95% CI [-1.3, 0.9]; p >0.99). Major bleeding rates were similar (5.2% in the interruption group vs. 6.5% in the continuation group; p = 0.39), but minor bleeding was significantly higher in the continuation group (10.1% vs 14.9%; p=0.027). The event rates were lower than expected, leaving the trial underpowered to detect clinically meaningful differences.
Dr. Jung-Min Ahn from the Asan Medical Center, Seoul, South Korea, concluded: “Continuing aspirin monotherapy did not reduce ischemic events, although it was associated with a modest increase in minor bleeding. Event rates were lower than expected, which may reflect the improved safety profile of contemporary DES…Our overall findings should be interpreted with caution. Further research in a large-scale, adequately powered study may now be needed, especially in higher-risk patients and where higher-risk surgeries are involved.”
- Halvorsen S, Mehilli J, Cassese S, et al. 2022 ESC Guidelines on cardiovascular assessment and management of patients undergoing non-cardiac surgery. Eur Heart J. 2022;43(39):3826-3924. doi:10.1093/eurheartj/ehac270
- Graham MM, Sessler DI, Parlow JL, et al. Aspirin in Patients With Previous Percutaneous Coronary Intervention Undergoing Noncardiac Surgery. Ann Intern Med. 2018;168(4):237. doi:10.7326/M17-2341