Adding Aspirin to Anticoagulation Sounds Smart: The Data Says Otherwise
Abdul Mannan, Consultant Haematologist at Betsi Cadwaladr University Health Board, posted on LinkedIn:
”Adding aspirin to anticoagulation sounds smart. The data says otherwise.
The ATIS-NVAF trial just gave us clear evidence about combination therapy in stroke patients with AF and atherosclerosis. These are exactly the patients where you’d think dual therapy makes sense.
Here’s what happened in 316 Japanese patients:
• No reduction in stroke or ischemic events (HR 0.76, p=0.41)
• Bleeding risk more than doubled (HR 2.42, p=0.008)
• Trial stopped early because continuing was pointless
• For every 9 patients on combination therapy, you cause 1 major bleed
The numbers are stark. Combination therapy gave you 19.5% bleeding vs 8.6% on anticoagulation alone. That’s an absolute increase of 11%. And you don’t prevent a single stroke.
This mirrors what we saw in AFIRE (2019) for AF with stable coronary disease. Anticoagulation alone was safer.
Bottom line for clinical practice: Stick with your DOAC or warfarin. Don’t routinely add aspirin or clopidogrel. The bleeding risk is real, and the benefit isn’t there.
Exception: acute coronary syndrome needing PCI. Follow your PCI guidelines, but get patients off dual therapy as quickly as safely.
ATIS-NVAF was published in JAMA Neurology (October 2025). Mean age 77 years, 41 centres, stopped at interim analysis for futility.
What’s your approach when stroke patients with AF also have significant coronary disease?”

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