Well-Controlled Warfarin Therapy In Acute Ischemic Stroke Patients With Atrial Fibrillation Associated With Lower Rate Of Lesion Recurrence

Objectives: The optimal timing of warfarin administration for acute ischemic patients with atrial fibrillation (AF) has not yet been established because the risk of early symptomatic recurrence is not high and hemorrhagic transformation commonly occurs. Recent studies have reported a high frequency of recurrent lesions detectable on diffusion-weighted MRI within a few weeks after acute ischemic stroke. We hypothesized that well-controlled warfarin therapy could prevent acute ischemic stroke patients with AF from developing recurrent lesions. Methods: We retrospectively examined consecutive acute ischemic stroke patients with AF treated in our hospital between 2008 and 2011 who were given warfarin within 2 weeks of admission and had diffusion-weighted MRI and blood test for prothrombin time and international normalized ratio (PT-INR) both on admission and at 2 weeks. Warfarin was started as early as possible and heparin (10,000 units a day) was also administered until the PT-INR target (2.0-3.0 for patients aged < 70 years or 1.6-2.6 for those ≥ 70 years recommended for the stroke patients with AF at chronic stage by Japanese Guideline for the Management of Stroke 2009) was achieved. We classified the enrolled patients into 2 groups according to their PT-INR: The well-controlled group (WCG) was defined as those in whom target PT-INR was achieved at 2 weeks, and those in whom the target could not be achieved at 2 weeks were classified as the poorly-controlled group (PCG). Results: There were 123 patients (median age of 79.0, 62 male and 61 female) who met the criteria for the present study, consisting of 52 WCG patients and 71 PCG patients. There were also no significant differences in demographics, common risk factors, severity of stroke, or median starting day of warfarin (second day from admission) between the 2 groups. The median PT-INR of WCG was 1.9 (1.7-2.3) and that of PCG was 1.6 (1.3-2.9), showing significant difference (P=0.0169). WCG had a significantly lower rate of new recurrent lesions on diffusion-weighted MRI at 2 weeks than PCG (17.3% vs. 36.6%, respectively, p=0.0190). Conclusions: Our findings suggested that well-controlled warfarin therapy with heparin bridging reduces the recurrence of lesions in acute ischemic stroke patients with AF.