Major bleeding remains the principal complication of oral anticoagulation. In patients with device-detected subclinical atrial fibrillation, the decision to anticoagulate requires careful balancing of stroke prevention against bleeding risk.

In this episode of CLOT Conversations, Dr. Deborah Siegal discusses a prespecified subanalysis of the ARTESiA randomized clinical trial, recently published in JAMA Cardiology. ARTESiA demonstrated a 37% reduction in stroke and systemic embolism with apixaban compared to aspirin — but at the cost of increased major bleeding.

This subanalysis goes deeper, examining the site, severity, and clinical course of bleeding events. Most bleeding was gastrointestinal and non-critical. Rates of intracranial and fatal bleeding were low and similar between treatment arms. The majority of events were not clinical emergencies, and many were defined by hemoglobin decline rather than catastrophic presentation.

We explore what these findings mean for individualized risk assessment, the importance of modifiable bleeding risk factors such as NSAID use, and how physicians and patients can approach shared decision-making in subclinical AF.

Abstract (subscription required for full paper):

Siegal DM, Sticherling C, Healey JS, McIntyre WF, Christensen LS, Parkash R, Vanassche T, Conen D, Gold M, Granger CB, Nielsen JC. Major Bleeding With Apixaban vs Aspirin: A Subanalysis of the ARTESiA Randomized Clinical Trial. JAMA cardiology. 2025 Dec;10(12):1305-14.

https://jamanetwork.com/journals/jamacardiology/fullarticle/2841075

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ARTESiA: Apixaban vs Aspirin Bleeding Risk with Dr D Siegal