What is the problem and what is known about it so far?

Patients with atrial fibrillation have an increased risk for blood clots in the heart that travel to the brain (causing a stroke) or other places in the body (also known as systemic blood clots). Blood-thinning medicines may help prevent blood clots in patients with atrial fibrillation. Apixaban and rivaroxaban are newer blood thinners that are being recommended over warfarin because of their improved safety. Although trials have individually compared apixaban and rivaroxaban with warfarin in patients with atrial fibrillation, few studies have compared the 2 treatments with each other.

Why did the researchers do this particular study?

To directly compare the safety and effectiveness of apixaban versus rivaroxaban in patients with atrial fibrillation.

Who was studied?

Patients over 18 years of age who were diagnosed with atrial fibrillation and received a new prescription for apixaban or rivaroxaban between 28 December 2012 and 1 January 2019. Patients were excluded if they had end-stage kidney disease, cancer, a history of blood clots, or a history of hip or knee surgery.

How was the study done?

The researchers studied information from a large health care claims database that includes information on patients covered by employer-sponsored health insurance or Medicare Advantage. They collected information on the patients' characteristics (for example, medical diagnoses, medications, and visits to health care facilities) and information on whether patients had the primary outcome (stroke or systemic blood clot) or the primary safety outcome (gastrointestinal bleeding or bleeding in the brain) after receiving a prescription for apixaban or rivaroxaban. The researchers compared the rates of the primary outcome and primary safety outcome between the 2 groups.

What did the researchers find?

The study included 39,351 patients who were prescribed apixaban and 39,351 prescribed rivaroxaban; the patients were matched so the 2 treatment groups were as similar as possible. The follow-up for both groups was about 290 days. The rivaroxaban group had a higher rate of stroke or systemic blood clots than the apixaban group, and the apixaban group had a lower rate of gastrointestinal bleeding or bleeding in the brain than the rivaroxaban group.

What were the limitations of the study?

The researchers did not have information on the patients' use of over-the-counter medications (such as aspirin) that may affect their risk for stroke or bleeding.

What are the implications of the study?

The results of this study suggest that apixaban may be safer and more effective than rivaroxaban in preventing strokes and systemic blood clots in patients with atrial fibrillation.

中文翻译：

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Apixaban与Rivaroxaban对房颤患者的有效性和安全性。

问题是什么，到目前为止对此有什么了解？

心房颤动的患者出现心脏血栓的风险增加，这些血栓会传播到大脑（引起中风）或身体其他部位（也称为全身性血凝块）。血液稀释药物可能有助于预防房颤患者的血凝块。阿pixaban和rivaroxaban是较新的血液稀释剂，由于其安全性提高而被推荐使用华法林。尽管试验分别比较了房颤患者中的apixaban和rivaroxaban与warfarin的疗效，但很少有研究将这两种疗法相互比较。

研究人员为什么要进行这项特殊研究？

直接比较阿哌沙班与利伐沙班在房颤患者中的安全性和有效性。

谁学的？

在2012年12月28日至2019年1月1日期间被诊断为房颤并接受新药apixaban或rivaroxaban的18岁以上患者。如果患者患有终末期肾脏疾病，癌症，有血栓史，或髋关节或膝盖手术史。

研究如何完成？

研究人员研究了来自大型医疗索赔数据库的信息，其中包括由雇主赞助的医疗保险或Medicare Advantage覆盖的患者信息。他们收集了有关患者特征的信息（例如，医疗诊断，用药和去医疗机构就诊），以及有关患者是否具有主要结局（中风或全身性血凝块）或主要安全结局（胃肠道出血或出血）的信息。在大脑中）接受阿哌沙班或利伐沙班的处方后。研究人员比较了两组之间主要结果和主要安全结果的发生率。

研究人员发现了什么？

该研究包括39,351名服用阿哌沙班的患者和39,351名服用利伐沙班的患者。由于患者匹配，因此两个治疗组尽可能相似。两组的随访时间均为290天。利伐沙班组的中风或全身性血凝块发生率高于阿哌沙班组，而阿哌沙班组的胃肠道出血或脑部出血率低于利伐沙班组。

研究的局限性是什么？

研究人员没有获得有关患者使用非处方药（例如阿司匹林）的信息，这些药物可能会影响中风或出血的风险。

该研究的意义是什么？

这项研究的结果表明，在预防房颤患者的中风和全身性血凝块方面，阿哌沙班可能比利伐沙班更安全，更有效。