How to Build the Plane While Flying: VTE/PE Thromboprophylaxis Clinical Guidelines for COVID-19 Patients.

Over the years, the practice of medicine has evolved from authority-based to experience-based to evidence-based with the introduction of the scientific process, clinical trials, and outcomes-based data analysis (Tebala GD. Int J Med Sci. 2018;15(12):1397-1405). The time required to perform the necessary randomized controlled trials, a systematic literature review, and meta-analysis of these trials to then create, accept, promulgate, and educate the practicing clinicians to use the evidence-based clinical guidelines is typically measured in years. When the severe acute respiratory syndrome novel coronavirus-2 (SARS-nCoV-2) pandemic commenced in Wuhan, China at the end of 2019, there were few available clinical guidelines to deploy, let alone adapt and adopt to treat the surge of coronavirus disease 2019 (COVID-19) patients. The aim of this study is to first explain how clinical guidelines, on which bedside clinicians have grown accustomed, can be created in the midst of a pandemic, with an evolving scientific understanding of the pathophysiology of the hypercoagulable state. The second is to adapt and adopt current venous thromboembolism diagnostic and treatment guidelines, while relying on the limited available observational reporting of COVID-19 patients to create a comprehensive clinical guideline to treat COVID-19 patients.

Rivaroxaban Versus Warfarin in African American Patients with Nonvalvular Atrial Fibrillation.

INTRODUCTION: Black patients are under-represented in randomized trials evaluating oral anticoagulants in non-valvular atrial fibrillation (NVAF). We sought to evaluate the effectiveness and safety of rivaroxaban versus warfarin in African Americans with NVAF. METHODS: We performed an analysis using Optum® De-Identified Electronic Health Record (EHR) data from 1/1/2012-9/30/2018. We included adult African American patients with a diagnosis of NVAF who were anticoagulant-naïve during the 12-months prior to initiation of rivaroxaban or warfarin. Patients receiving rivaroxaban were 1:1 propensity score matched to warfarin patients. Our primary effectiveness and safety outcomes were the 2-year incidence rates (%/year) of stroke or systemic embolism (SSE) and major bleeding using an intention-to-treat approach. Cohorts were compared using doubly-robust Cox regression and reported as hazard ratios (HRs) with 95% confidence intervals (CIs). RESULTS: We matched 4102 rivaroxaban and 4102 warfarin users with a median (interquartile range) available follow-up of 2.0 (0.9, 2.0) years. Median CHA2DS2-VASc and HASBLED scores were 3 (2, 4) and 2 (1, 3). Rivaroxaban use was associated with a lower risk of SSE (1.99 versus 2.48, HR = 0.77, 95%CI = 0.60-0.99), ischemic stroke (1.84 versus 2.37, HR = 0.76, 95%CI = 0.59-0.98) and major bleeding (4.22 versus 4.98, HR = 0.84, 95%CI = 0.70-0.99). No differences in intracranial hemorrhage or gastrointestinal bleeding were observed. Neither sensitivity analyses utilizing an on-treatment methodology nor inverse probability-of-treatment weighting showed significant differences in SSE or major bleeding between rivaroxaban and warfarin users. CONCLUSIONS: Rivaroxaban appeared at least as effective and safe as warfarin when used to manage African American patients with NVAF in routine practice.

Rivaroxaban versus warfarin for treatment and prevention of recurrence of venous thromboembolism in African American patients: a retrospective cohort analysis.

BACKGROUND: African Americans are under-represented in trials evaluating oral anticoagulants for the treatment of acute venous thromboembolism (VTE). The aim of this study was to evaluate the effectiveness and safety of rivaroxaban versus warfarin for the treatment of VTE in African Americans. METHODS: We utilized Optum® De-Identified Electronic Health Record data from 11/1/2012-9/30/2018. We included African Americans experiencing an acute VTE during a hospital or emergency department visit, who received rivaroxaban or warfarin as their first oral anticoagulant within 7-days of the acute VTE event and had ≥1 provider visit in the prior 12-months. Differences in baseline characteristics between cohorts were adjusted using inverse probability-of-treatment weighting based on propensity scores (standard differences < 0.10 were achieved for all covariates). Our primary endpoint was the composite of recurrent VTE or major bleeding at 6-months. Three- and 12-month timepoints were also assessed. Secondary endpoints included recurrent VTE and major bleeding as individual endpoints. Cohort risk was compared using Cox regression and reported as hazard ratios (HRs) with 95% confidence intervals (CIs). RESULTS: We identified 2097 rivaroxaban and 2842 warfarin users with incident VTE. At 6-months, no significant differences in the composite endpoint (HR = 0.96, 95%CI = 0.75-1.24), recurrent VTE (HR = 1.02, 95%CI = 0.76-1.36) or major bleeding alone (HR = 0.93, 95%CI = 0.59-1.47) were observed between cohorts. Analysis at 3- and 12-months provided consistent findings for these endpoints. CONCLUSIONS: In African Americans experiencing an acute VTE, no significant difference in the incidence of recurrent VTE or major bleeding was observed between patients receiving rivaroxaban or warfarin.