Fang Margaret C, Go Alan S, Chang Yuchiao, Borowsky Leila, Pomernacki Niela K, Singer Daniel E
Department of Medicine, University of California at San Francisco, San Francisco, California, USA.
J Am Coll Cardiol. 2008 Feb 26;51(8):810-5. doi: 10.1016/j.jacc.2007.09.065.
We assessed 5 risk stratification schemes for their ability to predict atrial fibrillation (AF)-related thromboembolism in a large community-based cohort.
Risk schemes can help target anticoagulant therapy for patients at highest risk for AF-related thromboembolism. We tested the predictive ability of 5 risk schemes: the Atrial Fibrillation Investigators, Stroke Prevention in Atrial Fibrillation, CHADS(2) (Congestive heart failure, Hypertension, Age >or= 75 years, Diabetes mellitus, and prior Stroke or transient ischemic attack) index, Framingham score, and the 7th American College of Chest Physicians Guidelines.
We followed a cohort of 13,559 adults with AF for a median of 6.0 years. Among non-warfarin users, we identified incident thromboembolism (ischemic stroke or peripheral embolism) and risk factors from clinical databases. Each scheme was divided into low, intermediate, and high predicted risk categories and applied to the cohort. Annualized thromboembolism rates and c-statistics (to assess discrimination) were calculated for each risk scheme.
We identified 685 validated thromboembolic events that occurred during 32,721 person-years off warfarin therapy. The risk schemes had only fair discriminating ability, with c-statistics ranging from 0.56 to 0.62. The proportion of patients assigned to individual risk categories varied widely across the schemes. The proportion categorized as low risk ranged from 11.7% to 37.1% across schemes, and the proportion considered high risk ranged from 16.4% to 80.4%.
Current risk schemes have comparable, but only limited, overall ability to predict thromboembolism in persons with AF. Recommendations for antithrombotic therapy may vary widely depending on which scheme is applied for individual patients. Better risk stratification is crucially needed to improve selection of AF patients for anticoagulant therapy.
我们评估了5种风险分层方案预测大型社区队列中与心房颤动（AF）相关的血栓栓塞事件的能力。
风险方案有助于针对发生AF相关血栓栓塞事件风险最高的患者进行抗凝治疗。我们测试了5种风险方案的预测能力：心房颤动调查员方案、心房颤动卒中预防方案、CHADS(2)（充血性心力衰竭、高血压、年龄≥75岁、糖尿病以及既往卒中或短暂性脑缺血发作）指数、弗雷明汉评分以及美国胸科医师学会第7版指南。
我们对13559名患有AF的成年人进行了中位时间为6.0年的随访。在未使用华法林的人群中，我们从临床数据库中确定了新发血栓栓塞事件（缺血性卒中或外周栓塞）及危险因素。每种方案都分为低、中、高预测风险类别，并应用于该队列。计算每种风险方案的年化血栓栓塞率和c统计量（用于评估区分度）。
我们确定了在32721人年的非华法林治疗期间发生的685例经证实的血栓栓塞事件。这些风险方案的区分能力一般，c统计量在0.56至0.62之间。不同方案中被分配到各个风险类别的患者比例差异很大。各方案中被归类为低风险的比例在11.7%至37.1%之间，被认为是高风险的比例在16.4%至80.4%之间。
目前的风险方案在预测AF患者血栓栓塞事件方面具有相当但有限的总体能力。根据应用于个体患者的方案不同，抗栓治疗的建议可能差异很大。迫切需要更好的风险分层以改善AF患者抗凝治疗的选择。
