[Sportschosun, Jang Jong-ho] A study has found that anticoagulant treatment can reduce complications even in atrial fibrillation patients who are not at high risk of stroke. A research team from the Division of Cardiology at Severance Cardiovascular Hospital, led by professors Jeong Bo-young, Yoo Hee-tae and Kim Dae-hoon, said on the 2nd that even atrial fibrillation patients at intermediate risk of stroke should receive blood-thinning treatment with anticoagulants to lower the incidence of complications such as stroke and embolism.
The findings, published in the latest issue of The New England Journal of Medicine (NEJM, IF 84.5), were presented on the 28th of last month at the 2026 annual scientific meeting of the European Society of Cardiology and the World Heart Federation in Munich, Germany.
Atrial fibrillation is an arrhythmia in which the heart beats irregularly. Blood can clot inside the heart, forming a thrombus. If the thrombus travels through the blood vessels and blocks a cerebral blood vessel, it can cause a stroke. Anticoagulants, which inhibit blood clotting, are used to prevent this.
Patients with atrial fibrillation are classified according to their stroke risk based on the CHA2DS2-VA score, including high- and intermediate-risk groups. Under current clinical guidelines, patients aged 75 or older who have a history of stroke, systemic embolism or similar conditions are classified as having high-risk atrial fibrillation, and anticoagulant treatment is strongly recommended.
By contrast, patients with only one stroke risk factor—such as hypertension, diabetes, heart failure, vascular disease or advanced age—are classified as being at intermediate risk. For them, the guidelines state that anticoagulant treatment "may be considered." This is because there have been few clinical trials directly comparing treatment outcomes according to anticoagulant use in intermediate-risk patients.
Jeong Bo-young's research team conducted a clinical trial to evaluate the efficacy and safety of anticoagulants in patients with intermediate-risk atrial fibrillation.
The team recruited 1,803 patients with intermediate stroke risk from 18 medical institutions in South Korea, including Severance Cardiovascular Hospital, and randomly assigned them to two groups. A total of 902 patients in Group A took anticoagulants, while 901 patients in Group B did not receive them.
Over 24 months, the researchers monitored the occurrence of stroke; systemic embolism, in which a thrombus formed in the heart or elsewhere blocks another blood vessel; major bleeding occurring in organs such as the brain or requiring a transfusion; and cardiovascular death caused by the heart or other cardiovascular conditions.
These events occurred in four patients in Group A and 13 patients in Group B. Over 24 months, the cumulative risk of occurrence was 69% lower in Group A than in Group B.
In particular, ischemic stroke or systemic embolism occurred in one patient in Group A and 10 patients in Group B, making the risk 90% lower in Group A.
The cumulative incidence of major bleeding, a concern associated with anticoagulant treatment, was similar in the two groups. No cardiovascular deaths occurred in either group.
The significance of the study is that, through a randomized clinical trial, it confirmed that anticoagulants can prevent complications such as stroke and thromboembolism in patients with intermediate-risk atrial fibrillation—whose treatment decisions previously lacked sufficient supporting evidence—without clearly increasing the risk of major bleeding.
Professor Jeong Bo-young said, "The study found that anticoagulant treatment also helps reduce major clinical events, including stroke, in atrial fibrillation patients with only one stroke risk factor." She added, "We expect this study to provide important evidence for deciding whether to administer anticoagulant treatment to intermediate-risk patients."
The study was conducted with support from the Ministry of Health and Welfare (MOHW)'s Patient-Centered Clinical Research Coordinating Project and other programs, under the direction of the National Evidence-based Healthcare Collaborating Agency.
Jang Jong-ho, Reporter bellho@sportschosun.com
This article has been translated by GripLabs Mingo AI.
