Doctors frequently ask when it is safe to stop aspirin after a heart stent, and a new study published in the New England Journal of Medicine offers a data-driven answer for high-risk patients. The A-CLOSE trial, presented at the European Society of Cardiology (ESC) Congress 2026 in Munich, found that continuing dual antiplatelet therapy (DAPT) for an additional 24 months reduced major cardiovascular events without increasing overall bleeding.
Examining the trade-offs
Professor Kim Byeong-keuk of Severance Hospital led the randomized trial, which enrolled 3,203 patients at 19 Korean centers. Participants had undergone drug-eluting stent implantation 12 months prior and carried features associated with high ischemic risk, such as acute coronary syndrome, diabetes, chronic kidney disease, or complex lesion anatomy.
Patients were assigned to receive clopidogrel alone or to continue DAPT with aspirin and clopidogrel. The study followed patients for an additional 24 months after enrollment (12 months post-stent, plus 24 months of treatment). The primary endpoint combined all-cause death, myocardial infarction, stent thrombosis, stroke, and bleeding, occurring in 5.0 percent of the monotherapy group and 5.1 percent of the extended DAPT group, meeting the criterion for noninferiority.
However, the composite outcome masked important differences. The ischemic endpoint occurred in 3.7 percent of the clopidogrel-alone group and 1.6 percent of the DAPT group. Bleeding events were 1.8 percent versus 4.1 percent, respectively. All-cause mortality was 1.3 percent with monotherapy and 0.4 percent with DAPT.
For clinicians, these figures suggest that while stopping aspirin reduces bleeding, it also removes a layer of protection against heart attacks and death. The study did not prove that one outcome outweighed the other, but it provided a clearer framework for making that individual assessment.
Who benefits most?
Professor Kim emphasized that the decision to stop aspirin should depend on the specific risk profile of the patient. The trial included factors such as left main disease, bifurcation lesions, chronic total occlusion, multivessel disease, and diffuse long lesions. Kim noted that the more risk factors a patient presented, the worse their outcomes.
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Current tools used to guide treatment decisions, such as the DAPT score, primarily rely on clinical characteristics and procedural details. The A-CLOSE trial adds angiographic and procedural information to the equation. Kim suggested that future analyses should compare the trial’s criteria with established scoring systems to refine how clinicians assess East Asian patients.
When weighing the decision to stop aspirin, doctors must balance the patient’s ischemic burden against their bleeding susceptibility. For patients with substantial ongoing risk, extended DAPT appears to provide a meaningful safety benefit. The trial did not determine how long treatment should continue beyond the study period.
Kim noted that the study population was specific, with all participants of Korean origin. The open-label design and fewer-than-expected events also influence how the results should be interpreted in broader clinical practice.
How the study fits in
Future work will examine how the results fit into wider secondary prevention. Whether lipid control or management of other risk factors modifies the benefit of extended DAPT also requires additional study. The trial focused on patients receiving clopidogrel.
The value of A-CLOSE lies in making the decision more informed. The study showed that treatment persistence did not differ substantially between the groups. Adding aspirin did not produce a marked reduction in adherence during the trial. The two groups showed broadly similar tolerability. This practical observation supports the use of extended therapy in the right patients.