Relationship Between Infarct Volume and Prothrombin Time-International Normalized Ratio in Ischemic Stroke Patients With Nonvalvular Atrial Fibrillation.
In Japan, warfarin treatment at prothrombin time-international normalized ratio (PT-INR) of 1.60-2.60 is recommended for elderly patients with nonvalvular atrial fibrillation (NVAF). But it remains unknown whether PT-INR 1.60-1.99 has a similar effect on stroke severity as a value >2.0. The purpose of this study was to clarify the association between infarct volume and PT-INR levels.



The 180 patients (mean age, 76 years [SD, 10 years], 53% male) selected from 429 consecutive ischemic stroke patients admitted within 48 h of onset between 2004 and 2014 with NVAF were included. We classified them into 4 groups according to their PT-INR values on admission: no warfarin (NW), 129 patients; PT-INR <1.60 (poor control: PC), 29 patients; PT-INR 1.60-1.99 (low-intensity control: LC), 14 patients; and PT-INR ≥2.00 (high-intensity control: HC), 8 patients. Median (interquartile range: IQR) of infarct volume was 55 mL (IQR 14-175) in the NW, 42 mL (IQR 27-170) in the PC, 36 mL (IQR 6-130) in the LC, and 11 mL (IQR 0-39) in the HC groups. The infarct volume of the HC group was significantly smaller than in the other 3 groups, but no difference existed between the LC and PC groups or the LC and NW groups.



Warfarin control at PT-INR of 1.60-1.99 is not effective for reducing the severity of ischemic stroke in NVAF patients.
Stroke Center, Kindai University Faculty of Medicine.
Mari
M
Matsumoto
Manabu
M
Sakaguchi
Shuhei
S
Okazaki
Kazuo
K
Hashikawa
Tsutomu
T
Takahashi
Masayasu
M
Matsumoto
Toshiho
T
Ohtsuki
Takeshi
T
Shimazu
Toshiki
T
Yoshimine
Hideki
H
Mochizuki
Kazuo
K
Kitagawa
D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000150:complications / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000503:physiopathology; D020520:Brain Infarction / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D016208:Databases, Factual; D005260:Female; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D011517:Prothrombin Time; D020521:Stroke / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D014057:Tomography, X-Ray Computed; D014859:Warfarin / Q000008:administration & dosage / Q000009:adverse effects
D014859:Warfarin