Background and Purpose- Oral anticoagulation therapy is standard of care for patients with nonvalvular atrial fibrillation to prevent stroke. This study compared rivaroxaban and warfarin for stroke and all-cause mortality risk reduction in a real-world setting. Methods- This retrospective cohort study (2011-2017) included de-identified patients from the Optum Clinformatics Database who started treatment with rivaroxaban or warfarin within 30 days following initial diagnosis of nonvalvular atrial fibrillation. Before nonvalvular atrial fibrillation diagnosis, patients had 6 months of continuous health plan enrollment and CHA2DS2-VASc score ≥2. Stroke severity was determined by the National Institutes of Health Stroke Scale, imputed based on machine learning algorithms. Stroke and all-cause mortality risks were compared by treatment using Cox proportional hazard regression, with inverse probability of treatment weighting to balance cohorts for baseline risk factors. Stratified analysis by treatment duration was also performed. Results- During a mean follow-up of 27 months, 175 (1.33/100 patient-years [PY]) rivaroxaban-treated and 536 (1.66/100 PY) warfarin-treated patients developed stroke. The inverse probability of treatment weighting model showed that rivaroxaban reduced stroke risk by 19% (hazard ratio [HR], 0.81 [95% CI, 0.73-0.91]). Analysis by stroke severity revealed risk reductions by rivaroxaban of 48% for severe stroke (National Institutes of Health Stroke Scale score, 16-42; HR, 0.52 [95% CI, 0.33-0.82]) and 19% for minor stroke (National Institutes of Health Stroke Scale score, 1 to <5; HR, 0.81 [95% CI, 0.68-0.96]), but no difference for moderate stroke (National Institutes of Health Stroke Scale score, 5 to <16; HR, 0.93 [95% CI, 0.78-1.10]). A total of 41 (0.31/100 PY) rivaroxaban-treated and 147 (0.44/100 PY) warfarin-treated patients died poststroke, 12 (0.09/100 PY) and 67 (0.20/100 PY) of whom died within 30 days, representing mortality risk reductions by rivaroxaban of 24% (HR, 0.76 [95% CI, 0.61-0.95]) poststroke and 59% (HR, 0.41 [95% CI, 0.28-0.60]) within 30 days. Conclusions- After the initial diagnosis of atrial fibrillation, patients treated with rivaroxaban versus warfarin had significant risk reduction for stroke, especially severe stroke, and all-cause mortality after a stroke. Findings from this observational study may help inform anticoagulant choice for stroke prevention in patients with nonvalvular atrial fibrillation.

中文翻译：

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利伐沙班和华法林治疗的房颤患者中风和死亡的风险。

背景和目的-口服抗凝治疗是非瓣膜性房颤患者预防中风的标准治疗方法。这项研究比较了利伐沙班和华法林在现实环境中降低中风和全因死亡率的风险。方法-这项回顾性队列研究（2011-2017）包括来自Optum Clinformatics数据库的身份不明的患者，这些患者在初步诊断为非瓣膜性心房颤动后30天内开始使用rivaroxaban或warfarin进行治疗。在诊断非瓣膜性心房颤动之前，患者已连续入学6个月且CHA2DS2-VASc评分≥2。中风的严重程度由美国国立卫生研究院中风量表确定，该量表是根据机器学习算法估算的。通过使用Cox比例风险回归进行治疗，比较了卒中和全因死亡率风险，并通过权重加权的概率与队列的基线风险因素进行了权衡。还根据治疗持续时间进行了分层分析。结果-在平均27个月的随访期间，有175名（1.33 / 100患者-年[PY]）利伐沙班治疗和536名（1.66 / 100 PY）华法林治疗的患者发生了中风。治疗加权模型的逆概率表明，利伐沙班将中风风险降低了19％（危险比[HR]，0.81 [95％CI，0.73-0.91]）。通过对中风严重程度的分析显示，对于严重中风（美国国立卫生研究院中风量表评分，16-42； HR，0.52 [95％CI，0.33-0.82]），利伐沙班降低了48％的风险；对于中风（国立卫生研究院），降低了19％健康中风量表评分的得分，从1到<5； HR，0。81 [95％CI，0.68-0.96]），但中度卒中无差异（美国国立卫生研究院卒中量表评分，5至<16； HR，0.93 [95％CI，0.78-1.10]）。中风后死于利伐沙班治疗的41例（0.31 / 100 PY）和华法林治疗的147例（0.44 / 100 PY），其中30天内死亡的12例（0.09 / 100 PY）和67例（0.20 / 100 PY），表示在30天内，利伐沙班降低了卒中后24％（HR，0.76 [95％CI，0.61-0.95]）和59％（HR，0.41 [95％CI，0.28-0.60]）的死亡风险。结论-初步诊断为房颤后，利伐沙班与华法林治疗的患者可显着降低中风风险，尤其是重度中风，以及中风后全因死亡率。