Objective: This study explored the thromboembolism risk of low-risk atrial fibrillation (AF) patients (CHA2DS2-VASc score of 0 or 1 for male and 1 or 2 for female) with different clinical characteristics to provide the basis for anticoagulation decision-making in these patients. Methods: We prospectively enrolled consecutive 2 862 nonvalvular low-risk AF patients between August 2011 to December 2018 in China-AF (China Atrial Fibrillation Registry) Study, their CHA2DS2-VASc score was 0 or 1 for male and 1 or 2 for female. According to their age, sex, presence or absence of hypertension, diabetes mellitus, congestive heart failure, and vascular disease at the time of enrolling, patients were divided into CHA2DS2-VASc score 0 score group, 1 score group, and 2 score group. Patients were followed up every 6 months by outpatient clinic visit or telephone interview. The outcome was a thromboembolic event, including ischemic stroke and systemic embolism. Univariate Cox regression analysis was used to compare the thromboembolism risk between the patients with different risk factors and CHA2DS2-VASc score 0 group. Results: A total of 2 862 low-risk atrial fibrillation patients were enrolled in this study. 915 patients (32.0%) were female, and age was (55.0±10.7) years old. There were 933 patients (32.6%) in CHA2DS2-VASc score 0 group, 1 401 patients (49.0%) in score 1 group and 528 patients (18.5%) in score 2 group. During follow-up (median 1.5 years, 5 811.82 person-years), 33 cases of thromboembolic events were recorded, the annual rate of thromboembolism was 0.57% (95%CI 0.40%~0.80%). The number of thromboembolic events in patients with CHA2DS2-VASc score 0, 1 and 2 were 8, 11 and 14, respectively, and the annual thromboembolism event rates were 0.40% (95%CI 0.20%-0.81%), 0.39% (95%CI 0.22%-0.71%) and 1.34% (95%CI 0.80%-2.27%), respectively. The risk of thromboembolism of CHA2DS2-VASc score 2 group (HR=3.53, 95%CI 1.48-8.44; P=0.005), especially female patients aged 65-74 years in CHA2DS2-VASc score 2 group (HR=2.67, 95%CI 1.63-4.38; P<0.000) was significantly higher than that in patients of CHA2DS2-VASc score 0 group. Conclusion: Low-Risk Atrial Fibrillation patients with CHA2DS2-VASc score 2, especially female patients aged 65-74 years old with CHA2DS2-VASc score 2 are at higher risk of thromboembolism in low-risk AF patients. For such patients, intensified oral anticoagulant therapy might be helpful to reduce the risk of thrombolism.
目的： 探讨不同临床特征低危心房颤动（房颤）患者（CHA2DS2-VASc评分男性≤1分，女性≤2分）的血栓栓塞风险，并为该类患者的抗凝决策提供依据。 方法： 前瞻性地连续入选2011年8月至2018年12月中国房颤注册研究中CHA2DS2-VASc评分男性≤1分，女性≤2分的非瓣膜性房颤患者。根据患者基线年龄、性别，以及合并高血压、糖尿病、慢性心力衰竭和血管疾病的情况，将其分为CHA2DS2-VASc评分0分组、1分组和2分组。所有患者每6个月电话或门诊随访1次，终点事件为包括缺血性卒中和系统性栓塞在内的血栓栓塞事件。计算血栓栓塞事件的年化发生率，并采用单因素Cox回归分析比较合并不同危险因素的房颤患者与CHA2DS2-VASc评分0分组之间血栓栓塞风险的差异。 结果： 共纳入2 862例低危房颤患者，女性915例（32.0%），年龄（55.0±10.7）岁。CHA2DS2-VASc评分0分组933例（32.6%），1分组1 401例（49.0%），2分组528例（18.5%）。随访期间（中位随访1.5年，共5 811.82人年）共发生33例血栓栓塞事件，整体年化发生率为0.57%（95%CI 0.40~0.80）。其中CHA2DS2-VASc评分0、1及2分组患者的血栓栓塞事件数分别为8、11及14例，年化发生率分别为0.40%（95%CI 0.20~0.81）、0.39%（95%CI 0.22~0.71）及1.34%（95%CI 0.80~2.27）。CHA2DS2-VASc评分2分组（HR=3.53，95%CI 1.48~8.44，P=0.005）及其中年龄65~74岁的女性患者（HR=2.67，95%CI 1.63~4.38，P<0.001）的血栓栓塞风险显著高于CHA2DS2-VASc评分0分组。 结论： 低危房颤患者中，年龄65~74岁的女性血栓栓塞风险较高，对于该类患者可能需要更积极地考虑口服抗凝治疗。.
Keywords: Atrial fibrillation; CHA(2)DS(2)-VASc score; Thromboembolism.