High-dose prophylactic anticoagulation benefits patients with COVID-19 pneumonia

Results inform current clinical practice

Over the course of the COVID-19 pandemic, “Patients hospitalized with COVID-19 manifested the highest risk for thromboembolic complications, especially patients in the intensive care setting,” and early reports suggested that standard prophylactic doses of anticoagulant therapy might be insufficient to prevent thrombotic events, Richard C. Becker, MD, of the University of Cincinnati, and Thomas L. Ortel, MD, of Duke University, Durham, N.C., wrote in an accompanying editorial.

“Although there have been several studies that have investigated the role of anticoagulant therapy in hospitalized patients with COVID-19, this is the first study that specifically compared a standard, prophylactic dose of low-molecular-weight heparin to a ‘high-dose’ prophylactic regimen and to a full therapeutic dose regimen,” Dr. Ortel said in an interview.

“Given the concerns about an increased thrombotic risk with prophylactic dose anticoagulation, and the potential bleeding risk associated with a full therapeutic dose of anticoagulation, this approach enabled the investigators to explore the efficacy and safety of an intermediate dose between these two extremes,” he said.

In the current study, “It was notable that the primary driver of the improved outcomes with the ‘high-dose’ prophylactic regimen reflected the fourfold reduction in macrovascular thrombosis, a finding that was not observed in other studies investigating anticoagulant therapy in hospitalized patients with severe COVID-19,” Dr. Ortel told this news organization. “Much initial concern about progression of disease in patients hospitalized with severe COVID-19 focused on the role of microvascular thrombosis, which appears to be less important in this process, or, alternatively, less responsive to anticoagulant therapy.”

The clinical takeaway from the study, Dr. Ortel said, is the decreased risk for venous thromboembolism with a high-dose prophylactic anticoagulation strategy compared with a standard-dose prophylactic regimen for patients hospitalized with hypoxemic COVID-19 pneumonia, “leading to an improved net clinical outcome.”

Looking ahead, “Additional research is needed to determine whether a higher dose of prophylactic anticoagulation would be beneficial for patients hospitalized with COVID-19 pneumonia who are not in an intensive care unit setting,” Dr. Ortel said. Studies are needed to determine whether therapeutic interventions are equally beneficial in patients with different coronavirus variants, since most patients in the current study were infected with the Delta variant, he added.

The study was supported by LEO Pharma. Dr. Labbé disclosed grants from LEO Pharma during the study and fees from AOP Health unrelated to the current study.

Dr. Becker disclosed personal fees from Novartis Data Safety Monitoring Board, Ionis Data Safety Monitoring Board, and Basking Biosciences Scientific Advisory Board unrelated to the current study. Dr. Ortel disclosed grants from the National Institutes of Health, Instrumentation Laboratory, Stago, and Siemens; contract fees from the Centers for Disease Control and Prevention; and honoraria from UpToDate unrelated to the current study.

A version of this article originally appeared on Medscape.com.