Kotalczyk Agnieszka, Guo Yutao, Wang Yutang, Lip Gregory Yh
Liverpool Centre for Cardiovascular Science, University of Liverpool and Liverpool Heart & Chest Hospital, Liverpool, UK.
Department of Cardiology, Congenital Heart Diseases and Electrotherapy, Medical University of Silesia, Silesian Centre for Heart Diseases, Zabrze, Poland.
Int J Stroke. 2021 Oct 18:17474930211053140. doi: 10.1177/17474930211053140.
Suboptimal low dosages of non-vitamin K antagonist oral anticoagulants (NOACs) are often inappropriately used due to a fear of bleeding, particularly among elderly patients. Such practice is common in Asia, and we aimed to evaluate the use of low-dose NOACs and their impact on clinical outcomes among Chinese patients with atrial fibrillation.
The Optimal Thromboprophylaxis in Elderly Chinese Patients with Atrial Fibrillation (ChiOTEAF) registry was a prospective, multicenter study conducted in China from October 2014 to December 2018. For this report, we included NOAC-treated patients with available data on NOAC dosage and one-year follow-up. Logistic regression analysis assessed the association (adjusted for age, sex, prior ischemic stroke, prior major bleeding, heart failure, coronary artery disease, hypertension, diabetes mellitus, chronic kidney disease, liver disease, current anemia) between the low doses and study outcomes among NOAC-treated patients, as well as comparisons with non-anticoagulated patients.
The eligible cohort included 1310 NOAC-treated patients (mean age of 72.1 ± 10.9; 38.9% female), of whom 341 (26.0%) received a low "off-label" dose. The use of low-dose NOACs was independently associated with higher odds of the composite outcome (OR: 2.51; 95% CI: 1.11-5.71) and thromboembolism (OR: 4.73; 95% CI: 1.11-20.01). Compared with non-anticoagulated patients, lower rates of the composite outcome (7.3% vs. 11.3%; = 0.025) and all-cause death (5.3% vs. 9.7%; = 0.007) were seen in the low-dose group (ORs 0.50; 95% CI: 0.32-0.78, and 0.42; 95% CI: 0.26-0.70, respectively).
Low doses of NOACs should not be recommended as a part of standard therapy among Chinese patients with atrial fibrillation as their use was associated with a higher odds ratio of the composite outcome and thromboembolic events compared with standard dose NOAC regimens. Compared to non-treatment, the use of low-dose NOAC may result in a survival benefit (but not thromboembolic reduction) among high-risk patients.
由于担心出血，非维生素K拮抗剂口服抗凝药（NOACs）的次优低剂量常常使用不当，尤其是在老年患者中。这种做法在亚洲很常见，我们旨在评估低剂量NOACs在中国房颤患者中的使用情况及其对临床结局的影响。
中国老年房颤患者最佳血栓预防（ChiOTEAF）登记研究是一项于2014年10月至2018年12月在中国进行的前瞻性、多中心研究。对于本报告，我们纳入了有NOAC剂量和一年随访可用数据的接受NOAC治疗的患者。逻辑回归分析评估了低剂量与接受NOAC治疗患者的研究结局之间的关联（根据年龄、性别、既往缺血性卒中、既往大出血、心力衰竭、冠状动脉疾病、高血压、糖尿病、慢性肾脏病、肝病、当前贫血进行调整），以及与未接受抗凝治疗患者的比较。
符合条件的队列包括1310例接受NOAC治疗的患者（平均年龄72.1±10.9岁；38.9% 为女性），其中341例（26.0%）接受了低“非标签”剂量。使用低剂量NOACs与复合结局（比值比：2.51；95%置信区间：1.11 - 5.71）和血栓栓塞（比值比：4.73；95%置信区间：1.11 - 20.01）的较高几率独立相关。与未接受抗凝治疗的患者相比，低剂量组的复合结局发生率较低（7.3% 对11.3%；P = 0.025）和全因死亡率较低（5.3% 对9.7%；P = 0.007）（比值比分别为0.50；95%置信区间：0.32 - 0.78和0.42；95%置信区间：0.26 - 0.70）。
不建议在中国房颤患者中将低剂量NOACs作为标准治疗的一部分，因为与标准剂量NOAC方案相比，其使用与复合结局和血栓栓塞事件的较高比值比相关。与不治疗相比，使用低剂量NOAC可能会使高危患者获得生存益处（但不能减少血栓栓塞）。
