American Society of Hematology living guidelines on the use of anticoagulation for thromboprophylaxis in patients with COVID-19: July 2021 update on postdischarge thromboprophylaxis

Abstract

Background: COVID-19 related acute illness is associated with an increased risk of venous thromboembolism (VTE). Objective: These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians and other health care professionals in decisions about the use of anticoagulation for thromboprophylaxis in patients with COVID-19 who do not have confirmed or suspected VTE. Methods: ASH formed a multidisciplinary guideline panel, including three patient representatives, and applied strategies to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including performing systematic evidence reviews (up to March 2021). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assess evidence and make recommendations, which were subject to public comment. Results: The panel agreed on one additional recommendation. The panel issued a conditional recommendation against the use of outpatient anticoagulant prophylaxis in patients with COVID-19 being discharged from the hospital who do not have suspected or confirmed VTE or another indication for anticoagulation. Conclusions: This recommendation was based on very low certainty in the evidence, underscoring the need for high-quality, randomized controlled trials assessing the role of post-discharge thromboprophylaxis. Other key research priorities include better evidence on assessing risk of thrombosis and bleeding outcomes in patients with COVID-19 after hospital discharge.

Long COVID: The Nature of Thrombotic Sequelae Determines the Necessity of Early Anticoagulation

“…The authors speculate that it is possible that patients at higher risk for vascular thromboembolic events (VaTEs) were on prophylactic anticoagulation at discharge, which may have contributed to the lower rates in the VaTEs group. Many guidelines also recommend the use of anticoagulants after discharge ( Barnes et al., 2020 ; Bikdeli et al., 2020 ; Moores et al., 2020 ; Spyropoulos et al., 2020 ; Vanassche et al., 2020 ; Cuker et al., 2022 ). ASH recently issued a conditional recommendation not to use outpatient anticoagulation prophylaxis for discharged COVID-19 patients without suspected or confirmed venous thromboembolism or other indications for anticoagulation ( Cuker et al., 2022 ).…”

“…Many guidelines also recommend the use of anticoagulants after discharge ( Barnes et al., 2020 ; Bikdeli et al., 2020 ; Moores et al., 2020 ; Spyropoulos et al., 2020 ; Vanassche et al., 2020 ; Cuker et al., 2022 ). ASH recently issued a conditional recommendation not to use outpatient anticoagulation prophylaxis for discharged COVID-19 patients without suspected or confirmed venous thromboembolism or other indications for anticoagulation ( Cuker et al., 2022 ). The panel judged that both the benefits and harms of thromboprophylaxis after discharge were negligible in absolute terms.…”

Commentary on the 2021 ASH Guidelines on use of anticoagulation in patients with COVID-19 being discharged from the hospital

“…A review of the evidence tables for the document reveals an overall low certainty in the evidence, which is consistent from data coming mostly from observational studies 1 . However, the evidence tables reveal in absolute terms benefits of 5 fewer deaths and 4 fewer VTE events per 1,000 COVID-19 inpatients with a post-discharge antithrombotic strategy versus 1 more major bleed per 1,000 patients 1 . The panel judged that both benefits and harms of post-discharge thromboprohylaxis was trivial, based on a defined estimated incidence of fewer than 5 events per 1,000 patients.…”

“…This is clearly apparent in the accelerated process of assessing and formulating clinical practice guidelines in order for them to be clinically meaningful during the compressed time frame of a pandemic. A good example of the natural tension that exists between methodological purity and clinical relevance of COVID-19 associated guidelines lies with the 2021 American Society of Hematology (ASH) Guidelines on use of anticoagulation in patients with COVID-19 being discharged from the hospital (Table 1) 1 .…”

“…The authors issued a conditional recommendation against the use of outpatient anticoagulant prophyalxis in patients with COVID-19 being discharged from the hospital 1 However, as the authors themselves suggest, the overall low quality of evidence on the topic of post-discharge thromboprophylaxis of hospitalized COVID-19 patients requires both careful interpretation and judgment of both direct evidence in this population as well as indirect evidence from non-COVID-19 hospitalized medically ill populations, and it is here that the authors' interpretations are subject to some bias or not entirely based on a holistic or complete interpretation of the available clinical data. Importantly, three main issues stand out: 1) definition of the relevant hospitalized COVID-19 patient population at high thrombotic risk post-discharge, 2) choice of relevant outcomes, including balancing desirable versus undesirable effects of a thromboprophylactic strategy, and 3) methods of incorporating high quality evidence in a timely fashion.…”