Circulation Journal
Online ISSN : 1347-4820
Print ISSN : 1346-9843
ISSN-L : 1346-9843
Clinical Investigation
Accumulation of Risk Factors Increases Risk of Thromboembolic Events in Patients With Nonvalvular Atrial Fibrillation
Hiroshi InoueTakashi NozawaTadakazu HiraiAtsushi IwasaKen OkumuraJong-Dae LeeAkihiko ShimizuMotonobu HayanoKatsusuke Yano
Author information
JOURNAL FREE ACCESS

2006 Volume 70 Issue 6 Pages 651-656

Details
Abstract

Background Accumulation of risk factors could increase thromboembolic event rates in patients with nonvalvular atrial fibrillation (NVAF). To validate this hypothesis, a post hoc analysis was performed to determine the relationship of risk levels and thromboembolic events in patients with NVAF from our previous prospective study. Methods and Results Risk levels were quantified using the CHADS2 index in 509 patients with NVAF (66.3±10.3 years old). One point each was given for patients with advanced age (≥75 years), hypertension, congestive heart failure, and diabetes mellitus, and 2 points, to those with prior ischemic stroke or transient ischemic attack. Patients with a CHADS2 score of 0 were classified as low risk, 1 to 2 a moderate risk and 3 or more were high risk. Because hypertrophic cardiomyopathy had emerged as an independent risk factor for thromboembolism, the original CHADS2 score was modified by adding 1 point to patients with hypertrophic cardiomyopathy. Warfarin was given to 263 patients (mean international normalized ratio (INR) at enrollment, 1.86), antiplatelets (aspirin or ticlopidine) to 163 patients and no antithrombotic therapy to 83. During a mean follow-up period of 2 years, 31 thromboembolic events occurred. As the risk level (modified CHADS2 score) increased, the event rate increased for both the patient groups receiving warfarin (p=0.035) and those not receiving warfarin (p=0.048). When a thromboembolic event occurred in patients who had been treated with warfarin, the mean INR level was 1.41. Twelve (75%) of 16 patients complicated with thromboembolism during warfarin treatment had INR levels below the optimal levels (1.6-2.6) for Japanese patients. Conclusion Accumulation of risk factors could increase risk of thromboembolic events in patients with NVAF. Adherence to the guidelines for anticoagulation therapy is recommended. (Circ J 2006; 70: 651 - 656)

Content from these authors
© 2006 THE JAPANESE CIRCULATION SOCIETY
Previous article Next article
feedback
Top