The devastating Coronavirus disease (COVID-19) pandemic is associated with a high prothrombotic state. It is unclear if the coagulation abnormalities occur because of the direct effect of SARS-CoV-2 or indirectly by the cytokine storm and endothelial damage or by a combination of mechanisms. There is a clear indication of in-hospital pharmacological thromboprophylaxis for every patient with COVID-19 after bleed risk assessment. However, there is much debate regarding the best dosage regimen, and there is no consensus on the role of extended thromboprophylaxis. This study aims to evaluate the safety and efficacy of rivaroxaban 10 mg once daily for 35 ± 4 days versus no intervention after hospital discharge in COVID-19 patients who were at increased risk for VTE and have received standard parenteral VTE prophylaxis during hospitalization. The composite efficacy endpoint is a combination of symptomatic VTE, VTE-related death, VTE detected by bilateral lower limbs venous duplex scan and computed tomography pulmonary angiogram on day 35 ± 4 posthospital discharge and symptomatic arterial thromboembolism (myocardial infarction, nonhemorrhagic stroke, major adverse limb events, and cardiovascular death) up to day 35 ± 4 posthospital discharge. The key safety outcome is the incidence of major bleeding according to ISTH criteria. The MICHELLE trial is expected to provide high-quality evidence around the role of extended thromboprophylaxis in COVID-19 and will help guide medical decisions in clinical practice.

中文翻译：

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使用利伐沙班治疗因 COVID-19 血栓形成延长预防的住院患者：MICHELLE 试验的基本原理和设计


毁灭性的冠状病毒病（COVID-19）大流行与高血栓前状态有关。目前尚不清楚凝血异常的发生是由于 SARS-CoV-2 的直接影响，还是细胞因子风暴和内皮损伤的间接影响，或者是多种机制的组合。在出血风险评估后，每位 COVID-19 患者都有明确的院内药物血栓预防迹象。然而，关于最佳剂量方案存在很多争论，并且对于延长血栓预防的作用也没有达成共识。本研究旨在评估 VTE 风险增加且在住院期间接受标准肠外 VTE 预防的 COVID-19 患者，每天一次服用利伐沙班 10 毫克，持续 35 ± 4 天，与出院后不进行干预相比的安全性和有效性。复合疗效终点是症状性 VTE、VTE 相关死亡、出院后第 35 ± 4 天通过双侧下肢静脉双重扫描和计算机断层扫描肺血管造影检测到的 VTE 以及症状性动脉血栓栓塞（心肌梗死、非出血性卒中、主要不良反应）的组合。肢体事件和心血管死亡）直至出院后 35 ± 4 天。关键的安全性结果是根据 ISTH 标准的大出血发生率。 MICHELLE 试验预计将为 COVID-19 中延长血栓预防的作用提供高质量证据，并将有助于指导临床实践中的医疗决策。