Japanese Nonvalvular Atrial Fibrillation-Embolism Secondary Prevention Cooperative Study "JNAF-ESP"


Phase N/A Results

Trial Description

To determine the efficacy and safety of conventional- and low-intensity warfarin therapy in non-valvular atrial fibrillation (NVAF).


  • Warfarin (Coumadin®)Drug
    Other Names: Coumadin
    Intervention Desc: Anticoagulant (Vitamin K antagonist)

Trial Design

Prospective, randomized, open-label trial of 115 patients at 19 centers.

Patient Involvement

The patients were randomly allocated into a conventional-intensity group (international normalized ratio [INR] 2.2 to 3.5) and a low-intensity group (INR 1.5 to 2.1). A brain CT scan, MRI examination, or both were performed once a year, regardless of the patient’s outcome. Patient follow-up continued for at least 2 years or until end point events occurred.


Type Measure Time Frame Safety Issue
Primary Brain infarction, embolism to other parts of the body, TIA, amaurosis fugax, or asymptomatic brain infarction confirmed with CT scanning or MRI.
Secondary Brain hemorrhage, retinal hemorrhage, or other severe hemorrhagic complications that were fatal; hospital admission for emergency treatment; or blood transfusion.


Japan Cardiovascular Research Foundation, research grants for Cardiovascular Disease (6A-1, 9A-8) from the Ministry of Health and Welfare of Japan