Post-discharge anticoagulant therapy suitable only for high-risk patients with COVID-19: JAMA

Universal prescription of post-discharge AC in patients with COVID-19 offers marginal clinical benefits and may cause harm in patients at high risk of bleeding. Given the unclear evidence, clinicians are facing the dilemma of which patients hospitalized with COVID-19 could benefit from post-discharge AC. Therefore, researchers of the Henry Ford Health System, Detroit, Michigan, conducted a study to quantify the rate of postdischarge arterial and venous thromboembolism in patients with COVID-19 and to identify the factors associated with the risk of post-discharge venous thromboembolism, and evaluate the association of post-discharge anticoagulation use with venous thromboembolism incidence.

In this cohort study, researchers included a total of 2832 patients hospitalized with COVID-19 enrolled at 5 hospitals of the Henry Ford Health System from March 1 to November 30, 2020. They analyzed anticoagulant therapy after discharge. The major outcome assessed as new onset of symptomatic arterial and venous thromboembolic events within 90 days after discharge from the index admission for COVID-19 infection that was identified using International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes.

Key findings of the study were:

• Upon analysis, the researchers noted that thirty-six patients (1.3%) had post-discharge venous thromboembolic events (16 pulmonary embolism, 18 deep vein thrombosis, and 2 portal vein thrombosis).
• They observed fifteen (0.5%) post-discharge arterial thromboembolic events (1 transient ischemic attack and 14 acute coronary syndrome).
• They found that the risk of venous thromboembolism decreased with time, with a median (IQR) time to event of 16 (7-43) days.
• However, they noted no change in the risk of arterial thromboembolism with time, with a median (IQR) time to event of 37 (10-63) days.
• They found that patients with a history of

◊Venous thromboembolism (odds ratio [OR], 3.24),

◊Peak dimerized plasmin fragment D (D-dimer) level greater than 3 μg/mL (OR, 3.76), and

◊Predischarge C-reactive protein level greater than 10 mg/dL (OR, 3.02) were more likely to experience venous thromboembolism after discharge.

• They noted that prescriptions for therapeutic anticoagulation at discharge were associated with a reduced incidence of venous thromboembolism (OR, 0.18).

This cohort study reiterated the low incidence of symptomatic VTE in patients with COVID-19 after discharge, which was comparable to other studies. It also stressed that some COVID-19 patients may need to begin AC therapy post-discharge to combat the risk of venous thromboembolism. Further randomized controlled studies might be necessary to have a major impact and standardize its use in clinical practice.

The authors concluded, "Although extended thromboprophylaxis in unselected patients with COVID-19 is not supported, these findings suggest that postdischarge anticoagulation may be considered for high-risk patients who have a history of venous thromboembolism, peak D-dimer level greater than 3 μg/mL, and predischarge C-reactive protein level greater than 10 mg/dL, if their bleeding risk is low."

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DOI:10.1001/jamanetworkopen.2021.35397