Younger patients with atrial fibrillation but no other risk factors for stroke are not likely to benefit from blood-thinning drugs, according to results presented at the 2024 American Heart Association's Scientific Sessions in Chicago.

“Although numerous observational studies have reported an association between Afib and cognitive decline, we found that anticoagulation therapy initiated in relatively younger adults with AFib did not reduce this risk,” study leader Lena Rivard, MD, said in a statement

In the Candian trial involving 1,235 otherwise healthy adults under age 65 with atrial fibrillation, prescribing anti-clotting medications did not reduce patients' risk of cognitive decline, strokes or transient ischemic attacks (TIAs).

None of the study participants had stroke risk factors such as diabetes, heart failure, high blood pressure, or a prior stroke or TIA. Half of them received 15 milligrams daily of rivaroxaban (Xarelto). The others received a placebo.

The trial was originally expected to continue for 5 years but was terminated at an average follow-up of 3.7 years after an independent monitoring committee determined a clear lack of benefit from the medication.

There were no differences in the outcomes of cognitive decline, stroke or TIA between those taking rivaroxaban and those receiving a placebo, researchers reported. The annual rates of these conditions combined were 7% with rivaroxaban and 6.4% with placebo.

“In clinical practice, people younger than age 65 with AFib tend to be overtreated with anticoagulant therapy, while older people who have indications for anticoagulation are under-treated,” Dr. Rivard said. “Our study supports current guidelines by confirming that younger people with Afib but no other risk factors for stroke have a low rate of stroke, and anticoagulation is not useful in reducing the risk of cognitive decline.”