Epidemiology of Anticoagulation in Atrial Fibrillation

我们建议继续对来自北加州凯撒医疗保健计划（“凯撒”）的13559例房颤（AF）患者的独特信息队列进行研究。我们的总体目标仍然是通过改善抗凝治疗患者的选择和改善抗凝治疗的管理来优化房颤卒中的预防。房颤是最常见的心律失常。它的频率随着年龄的增长而显著增加，在80岁以上的人群中达到近10%的患病率。房颤也是中风的一个重要危险因素，使中风风险增加5倍。随机试验（rct）已经证实抗凝在很大程度上消除了房颤引起的中风风险。尽管如此，华法林仍然是一种负担沉重且有风险的治疗方法。华法林治疗在现实条件下是否有益，存在相当大的不确定性。指南要求长期抗凝，并建议老年人使用抗凝剂。然而，这些随机对照试验相对较短，平均随访时间仅为18个月，并且很少有大于或等于80岁的患者被研究。在目前2.7年的资金支持下，我们已经建立了方法来收集一个非常大的房颤队列，描述基线特征和华法林状态，并跟踪血栓栓塞和出血事件。这是通过全面的自动化临床和行政凯撒数据库辅以医疗图表审查有效地完成的。我们的房颤队列的持续随访将提供抗凝治疗的长期影响和抗凝治疗对老年房颤患者的影响的独特评估。此外，我们将能够解决其他重要的争议，包括大于或等于65岁且无其他卒中危险因素的患者是否需要抗凝治疗，以及老年房颤患者的最佳抗凝强度。此外，我们将讨论雌激素替代疗法显著提高房颤女性卒中风险的新发现。总之，我们的队列研究将有效地为优化许多老年房颤患者的卒中预防策略提供强有力的见解。

We propose to continue our studies of a uniquely informative cohort of greater than 13,559 patients with atrial fibrillation (AF) from Kaiser Medical Care Program of Northern California ("Kaiser"). Our overall goal remains to optimize prevention of stroke in AF by improving selection of patients treated with anticoagulants, and by improving the management of anticoagulation. AF is the most common significant cardiac rhythm disorder. Its frequency increases strikingly with age, reaching a prevalence of nearly 10 percent in those over age 80. AF is also a powerful risk factor for stroke, raising this risk 5-fold. Randomized trials (RCTs) have established that anticoagulation largely removes the stroke risk posed by AF. Nonetheless, warfarin remains a burdensome and risky therapy. There is considerable uncertainty whether warfarin therapy will prove beneficial under real-world conditions. Guidelines call for long-term anticoagulation, and for use of anticoagulants in the elderly. Yet, the RCTs were relatively brief, with a mean follow-up of only 18 months, and few patients greater than or equal to 80 years old were studied. During the 2.7 years of current funding we have established methods to assemble a very large AF cohort, characterize baseline features and warfarin status, and follow for thromboembolic and hemorrhagic events. This has been accomplished efficiently via comprehensive automated clinical and administrative Kaiser databases supplemented by medical chart review. Continued follow-up of our AF cohort will provide unique assessments of both the long-term impact of anticoagulation and the impact of anticoagulation among the oldest patients with AF. Further, we will be able to address other important controversies including the need for anticoagulation in patients greater than or equal to 65 years old without other risk factors for stroke, and the optimal intensity of anticoagulation in older AF patients. In addition, we will address the provocative new finding that estrogen replacement therapy substantially raises the risk of stroke among women with AF. In all, continued study of our cohort will efficiently provide powerful insights into optimizing stroke prevention strategies for the many older Americans with AF.