Adding aspirin to dual antiplatelet therapy after percutaneous coronary intervention did not increase bleeding risk and may protect against coronary events.
An aspirin-free strategy did not reduce the major bleeding rate compared with a dual antiplatelet strategy, including aspirin, in the first month after patients with high bleeding risk underwent a percutaneous coronary intervention (PCI). However, STOPDAPT-3 results, which were presented at ESC Congress 2023, suggested there may be an increased risk for coronary events in patients not receiving aspirin.
Masahiro Natsuaki, MD, and colleagues investigated the role of aspirin in the context of dual antiplatelet therapy in the first month after PCI. They hypothesized that omitting aspirin from a dual antiplatelet strategy could reduce the risk for bleeding in the first month after PCI in patients with acute coronary syndrome (ACS) or patients with high bleeding risk, without increasing the risk for cardiovascular events.
To test this hypothesis, the phase 4 STOPDAPT-3 study enrolled 6,002 participants with ACS or high bleeding risk undergoing PCI with an everolimus-eluting stent from 72 centers in Japan. The participants were randomly assigned to receive either prasugrel (20 mg loading dose followed by 3.75 mg per day) plus aspirin (81-100 mg per day), or prasugrel monotherapy. Co-primary endpoints were BARC type 3,4, or 5 bleeding and a composite of cardiovascular death, myocardial infarction, definite stent thrombosis, or ischemic stroke at 1 month.
Major bleeding occurred in 4.71% of the participants in the dual therapy arm and 4.47% in the no-aspirin arm, demonstrating that omitting aspirin is not superior to a dual platelet therapy strategy in terms of bleeding risk (HR, 0.95; 95% CI, 0.75–1.20; P=0.66). Next, the no-aspirin arm was noninferior to the dual therapy arm regarding the composite outcome of cardiovascular events (4.12% vs 3.69%; HR, 1.12; 95% CI, 0.87–1.45; Pnon-inferiority=0.01). “However, the risk for sub-acute stent thrombosis appeared to be higher in the no-aspirin arm (HR, 3.40; 95% CI, 1.26–9.23),” added Dr. Natsuaki. Similarly, the risk for unplanned coronary revascularization may be higher in the no-aspirin group (HR, 1.83; 95% CI, 1.01–3.30).
“The use of aspirin as a component of dual antiplatelet therapy may have an additional protective effect on the vulnerable coronary lesions in the first month after PCI, without increasing the risk for major bleeding,” argued Dr. Natsuaki. “The dual therapy approach remains the standard of care in the first month after PCI.”
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