Department of Cardiovascular Medicine, University of South Florida, Tampa, Florida, USA.
Clin Cardiol. 2011 Oct;34(10):640-4. doi: 10.1002/clc.20967.
According to the American College of Cardiology/American Heart Association/European Society of Cardiology guidelines, the choice of aspirin or warfarin to prevent thromboembolic events (TEs) in patients with nonrheumatic atrial fibrillation (AF) should be based on the CHADS(2) score. The purpose of this study was to determine the predictors of warfarin use in patients with AF at low (CHADS(2) =0) or intermediate (CHADS(2) =1) risk for TEs.
Warfarin use is low in intermediate- and low-risk patients.
Clinical characteristics of 3086 consecutive patients (mean age, 70 ± 13 years) with nonrheumatic AF from an academic multispecialty practice were determined between 2006 and 2008 through individual chart review. Patients were identified based on an inpatient or outpatient encounter, in which a billing diagnosis code of AF or atrial flutter (AFl) was recorded. The decision for anticoagulation was at the discretion of the primary care physician or cardiologist. No intervention to guide anticoagulant therapy was made.
Warfarin was prescribed in 180/497 low-risk patients (36%), and in 646/938 intermediate-risk patients (69%). Among high-risk patients (CHADS(2) ≥2), warfarin was used in 792/968 patients (82%) with a CHADS(2) = 2, in 343/410 patients (84%) with a CHADS(2) =3, and in 225/273 patients (82%) with a CHADS(2) ≥4. On multivariate analysis, independent predictors of warfarin use in low-risk patients were nonparoxysmal AF (odds ratio [OR]: 5.02, P<0.0001) and age between 65 and 74 years (OR: 2.21, P<0.0001). Among intermediate-risk patients, congestive heart failure (OR: 7.34, P<0.0001), nonparoxysmal AF (OR: 4.04, P<0.0001), coronary artery disease (OR: 2.53, P<0.0001), age between 65 and 74 years (OR: 1.68, P = 0.002), and female gender (OR: 1.69, P = 0.002) were independent predictors of warfarin use. Lack of warfarin use (OR: 4.9, P<0.001) and female gender (OR: 2.0, P = 0.03) were associated with a higher risk of TEs in intermediate-risk patients. None of the CHADS(2) parameters was predictive of TEs. Warfarin was not associated with reduction in TEs in low-risk patients. Warfarin use did not have a significant effect on bleeding.
Although either aspirin or warfarin is recommended to prevent TEs in patients with AF at intermediate risk for TEs, warfarin is preferred in the majority of patients in general practice. Lack of warfarin use is associated with a higher risk of TEs in intermediate-risk patients with AF. The adoption of new oral anticoagulants that have lower risk of major hemorrhage than warfarin for low- or intermediate-risk AF patients remains to be determined.
根据美国心脏病学会/美国心脏协会/欧洲心脏病学会指南，非风湿性心房颤动（AF）患者预防血栓栓塞事件（TEs）的阿司匹林或华法林的选择应基于 CHADS₂ 评分。本研究的目的是确定 CHADS₂ 评分低（=0）或中（=1）风险的 AF 患者使用华法林的预测因素。
中低风险患者使用华法林的比例较低。
通过对 2006 年至 2008 年期间在学术多专科实践中的 3086 例非风湿性 AF 连续患者（平均年龄 70±13 岁）的临床特征进行个体图表回顾来确定。根据住院或门诊就诊确定患者，其中记录 AF 或心房扑动（AFl）的计费诊断代码。抗凝的决定由初级保健医生或心脏病专家决定。没有进行指导抗凝治疗的干预措施。
低危患者（CHADS₂≤1）中有 180/497 例（36%）使用华法林，中危患者（CHADS₂=2）中有 646/938 例（69%）使用华法林。在高危患者（CHADS₂≥2）中，华法林用于 CHADS₂=2 的 792/968 例患者（82%）、CHADS₂=3 的 343/410 例患者（84%）和 CHADS₂≥4 的 225/273 例患者（82%）。多变量分析显示，低危患者使用华法林的独立预测因素是非阵发性 AF（比值比 [OR]：5.02，P<0.0001）和 65-74 岁年龄（OR：2.21，P<0.0001）。在中危患者中，充血性心力衰竭（OR：7.34，P<0.0001）、非阵发性 AF（OR：4.04，P<0.0001）、冠心病（OR：2.53，P<0.0001）、65-74 岁年龄（OR：1.68，P=0.002）和女性（OR：1.69，P=0.002）是使用华法林的独立预测因素。中危患者中缺乏华法林治疗（OR：4.9，P<0.001）和女性（OR：2.0，P=0.03）与 TEs 风险增加相关。CHADS₂ 各参数均不能预测 TEs。华法林并未降低低危患者的 TEs 风险。华法林的使用并未显著增加出血风险。
尽管推荐在中危 TEs 风险的 AF 患者中使用阿司匹林或华法林预防 TEs，但在一般实践中，大多数患者更倾向于使用华法林。在中危 AF 患者中，缺乏华法林治疗与 TEs 风险增加相关。对于低危或中危 AF 患者，使用新型口服抗凝剂（与华法林相比，大出血风险较低）仍有待确定。
