2022 AF Symposium
The LOOP Study–Implications for Clinical Practice and Future Trials
Dr. Andrea Russo of Cooper University Hospital in Camden, New Jersey gave a talk on “The LOOP Study – Implications for Clinical Practice and Future Trials”.

Dr. Andrea Russo
A-Fib Strokes More Dangerous
She described how one-third of strokes are due to A-Fib. And these strokes are more severe and debilitating than those not associated with A-Fib.
Asymptomatic A-Fib may not be diagnosed until after someone has a stroke or heart attack. Dr. Russo described how previous studies defined “device detected A-Fib” as lasting more than 6 minutes but less than 24 hours duration without a prior diagnosis of A-Fib.
The LOOP Study Research
From 4 centers in Denmark, the LOOP Implantable Recorder Study investigated whether anticoagulation can prevent stroke in patients with high risk of stroke.
Participants: In the study, 318 patients, with no prior A-Fib, were over 70 years old (average age was 75 or over) and had at least one risk factor for stroke. They each received an implantable loop recorder (ILR), the Reveal LINQ (by Medtronic).
The control group received standard care (an annual interview with a study nurse and typical interactions with the participant’s general practitioner.)
Patients were monitored and followed for 2-3 years (medium follow-up 64 months).
Study Results
For both groups, the primary outcome was stroke or systemic embolism. Anticoagulation was recommended if someone had A-Fib for 6 minutes or longer.
A-Fib was detected in 32% of the implanted loop recorder group while in only 13% of the control group who received usual care.
There was no significant difference between the groups in major bleeding and hemorrhagic stroke.
Of the LOOP group, 4.5% suffered a primary outcome (stroke or embolism) compared to 5.6% of the control group.
Short Duration A-Fib Not a Risk
The researchers posed the question: Is all A-Fib worth seeing or worrying over? “Does all detected A-Fib require anticoagulation?” Is 6 minutes of A-Fib really a threat?
Dr. Russo cited other studies such as ASSERT where 6-24 hours of A-Fib wasn’t significant as a risk of stroke, whereas over 24 hours duration was. (See my report: How Long Does It Take for an A-Fib Clot to Form? The ASSERT Clinical Trial )
Researchers also asked: What other considerations should be examined? What about A-Fib burden?
Editor’s Comments
Dr. Russo is going against the grain of conventional A-Fib thought by suggesting that 6 minutes of A-Fib is not a serious threat or risk of developing an A-Fib stroke.
If you only have an occasional, short episode of A-Fib, you may not need an anticoagulant. If your doctor insists that you take an anticoagulant, it might be time to get a second opinion.
Remember that anticoagulants are considered high risk drugs. They should only be prescribed if there is a real risk of stroke.
If you find any errors on this page, email us. Y Last updated: Friday, February 25, 2022
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