长期口服抗凝治疗（OAC）引起的溶血风险在非瓣膜性心房颤动（AF）患者中是否合并癌症存在不一致的观点。本研究旨在澄清长期OAC治疗期间，患有癌症的AF患者与无癌症的AF患者之间出血风险的差异。 本次观察性研究通过CODE-AF前瞻性登记，纳入了韩国10个三级转诊中心的连续5902名AF患者。其中，464名（7.8%）被诊断出患有癌症，并对所有中风和出血事件（净复合事件）进行随访观察。 两组患者的年龄、CHA2DS2-VASC和HAS-BLED分数相似，男性占AF合并癌症患者的比例较高。与无癌症患者相比，他们同样被开具直接OAC处方。 AF合并癌症患者的临床相关非重大出血事件（CRNM）发生率高于无癌症患者（每100人年发生4.4次对比每100人年发生2.8次，P = 0.023），净复合事件在AF合并癌症患者中也更为频繁（每100人年发生6.4次对比每100人年发生4.0次，P = 0.004)。 AF合并癌症患者的CRNM出血率明显较高（危险比[HR] 1.54，置信区间[CI] 1.05-2.25，P = 0.002）与无癌症患者相比。 基于AF队列研究结果显示，AF合并癌症患者在长期口服抗凝治疗中存在明显较高的CRNM出血风险。

Comparison of the bleeding risk for long-term oral anticoagulation (OAC) in patients with nonvalvular atrial fibrillation (AF) with and without cancers has been inconsistent. This study aimed to clarify the differences in the bleeding risk in patients with AF with cancers and those without cancers during the long-term OAC.The CODE-AF prospective registry enrolled 5,902 consecutive patients treated for AF at 10 tertiary referral centers in Korea. Of the enrolled patients, 464 (7.8%) were diagnosed with cancers and were followed for all stroke and bleeding events (net composite events).The age, CHA2DS2-VASC, and HAS-BLED scores were similar between AF patients with and without cancers. Male population greatly comprised patients with AF with cancers. They were equally prescribed with direct OAC compared to those without cancers. The incidence rate for clinically relevant nonmajor (CRNM) bleeding events was higher in the patients with AF with cancers than in those without cancers (4.4 per 100 person-years versus 2.8 per 100 person-years, P = 0.023), and net composite events were also more frequent in patients with AF with cancers than in those without cancers (6.4 per 100 person-years versus 4.0 per 100 person-years, P = 0.004). Patients with AF with cancers showed a significantly higher rate of CRNM bleeding (hazard ratio [HR] 1.54, confidence interval [CI] 1.05-2.25, P = 0.002) than those without cancers.Based on the AF cohort, AF with cancers could face a significantly higher risk for CRNM bleeding events in the long-term OAC than those without cancers.