Key Updates in Thrombosis – August 2022
Table of Contents
A high point in thromboprophylaxis during pregnancy: The Highlow trial
Conducting randomized trials (RCTs) is critical but also costly and challenging, more so for pregnant patients. Dr. Middeldorp presented the results of the Highlow trial at ISTH 2022. Highlow randomized pregnant patients with prior venous thromboembolism (VTE) to intermediate-dose vs. low-dose anticoagulation with low-molecular-weight heparins. Among 1,110 randomized patients, there was no significantly reduced risk of the primary outcome, a composite of deep vein thrombosis, pulmonary embolism, or VTE in unusual sites during pregnancy or within 6 weeks postpartum with intermediate-dose vs. low-dose anticoagulation (2.0% vs 2.9%).
Thousands of articles, including dozens of RCTs, have attempted to address the risk of thrombosis associated with COVID-19, many already sharing their findings. It is in this spirit that the ISTH released new guidelines for antithrombotic therapy for prevention of thrombotic events and improving outcomes in patients with COVID-19. Some RCTs and a large-scale pooled analysis by the World Health Organization are still ongoing and the results may share additional insights for these decisions. Learn more.
Using the data from RIETE, a large ongoing VTE registry, the authors compared patient characteristics and outcomes of patients with distal DVT and proximal DVT. Patients with distal DVT were generally less sick and had lower rates of mortality and recurrent VTE than those with proximal DVT. The risk of recurrent VTE remained significant in multivariable models. Nevertheless, these rates were higher than in the normal population. In addition, over 40% of those with distal DVT had signs or symptoms of post-thrombotic syndrome at 1-year follow-up. Learn more.
In a complex machine-learning analysis of nearly 2 million admissions, the authors developed and validated an algorithm for predicting new PE in hospitalized patients. The reference standard for detection of PE was the International Classification of Disease (ICD) codes. The area under the curve for model performance was 0.87. The PE prediction model showed potential as a clinical tool to assist with PE detection. However, the study was based on existing data and needs validation in prospective nature, ideally in the form of a randomized trial. Learn more.
Behnood Bikdeli, MD, MS
Cardiologist, Section of Vascular Medicine, Division of Cardiovascular Medicine, Brigham and Women’s Hospital
Investigator, Thrombosis Research Group, Division of Cardiovascular Medicine, Brigham and Women’s Hospital
Instructor, Harvard Medical School
Investigator, Yale/ YNHH Center for Outcomes Research and Evaluation, Yale School of Medicine
Investigator, Cardiovascular Research Foundation
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