The first 90 days of warfarin, age 80 years, and international normalized ratio (INR) 4.0 were associated with increased risk despite trial-leel anticoagulation control.

• 在开始的90天，与抗凝组相对照，年龄80岁以上其国际标准化比值(INR)为4.；0者与风险增加有关联。