Atrial fibrillation is a common heart rhythm problem that can raise the chance of a stroke. Doctors often give blood thinners to people with this condition, but it has been unclear whether those at moderate risk benefit. A new study from South Korea tested a direct oral anticoagulant (DOAC) in patients with atrial fibrillation who were not at high risk.
The study included 1,803 patients. All had a CHADS-VASc score of 1 (men) or 2 (women), which means they had a moderate risk of stroke. Half received a DOAC, and half received no blood thinner. The researchers followed them for 24 months.
The main finding was that the group taking the DOAC had a much lower chance of the combined outcome of stroke, systemic embolism (a clot in the body), major bleeding, or death from heart causes. About 0.5% of people on the DOAC had this combined outcome, compared with 1.5% of those not taking it. That is about a 70% lower chance. The result was statistically significant.
When looking at stroke alone, the DOAC group also did better: 0.3% had a stroke versus 1.1% in the no-treatment group. Systemic embolism and major bleeding were similar in both groups. Serious side effects happened in about 9% of people in both groups. No one died from heart causes in either group.
The study was open-label, meaning patients and doctors knew who was taking the drug. This could affect how results are reported. Also, the number of events was small, so the findings need to be confirmed in larger studies. The research was funded by the Ministry of Health and Welfare, South Korea, and others.
For patients with atrial fibrillation and moderate stroke risk, this study suggests that taking a DOAC may lower the chance of stroke and other serious problems. However, treatment decisions should be made with a doctor, considering each person's situation.
