May 15, 2020
Colorado Study Uses Thromboelastography to Identify Clot Risk in COVID-19 Patients
May 15, 2020—The American College of Surgeons (ACS) announced publication of a study by Franklin L. Wright, MD, et al online in Journal of the American College of Surgeons (JACS) that found critically ill patients infected with COVID-19 were at high risk for developing renal failure, venous blood clots, and other complications associated with blood clots, such as stroke. The investigators are from the University of Colorado Anschutz Medical Campus in Aurora, Colorado.
The study, which linked blood clotting measurements with actual patient outcomes, builds on growing evidence that COVID-19–infected patients are highly predisposed to developing blood clots. The investigators are now participating in a randomized clinical trial of a drug that breaks down blood clots in these patients.
In the ACS press release, Dr. Wright noted that in patients with COVID-19 who develop disseminated intravascular coagulation (DIC), the clotting appears to be particularly severe and—as evidenced by case studies in China and elsewhere—clots in these patients do not appear to dissipate.
Trauma acute care surgeons and intensive care physicians who treat trauma, transplant, and cardiothoracic surgery patients at UCHealth University of Colorado Hospital saw the potential of using a specialized coagulation test to examine clotting issues in COVID-19 patients. According to ACS, the investigators used thromboelastography (TEG). The whole blood assay provides a broad picture of how an individual patient's blood forms clots, including how long clotting takes, how strong clots are, and how soon clots break down.
“This is an early step on the road to discovering treatments to prevent some of the complications that come with this disease,” commented Dr. Wright in the ACS announcement. Dr. Wright, who is Assistant Professor of Surgery at the University of Colorado School of Medicine, continued, “The COVID-19 pandemic is opening doors for multidisciplinary collaboration so trauma acute care surgeons and intensivists can bring the tools they use in their day-to-day lives and apply them in the critical care setting to new problems.”
The study in JACS is titled, “Fibrinolysis Shutdown Correlates to Thromboembolic Events in Severe COVID-19 Infection.” As summarized in the abstract, the analysis was composed of 44 patients with COVID-19. Investigators confirmed derangements in coagulation laboratory values including elevated D-Dimer, fibrinogen, prothrombin time, and partial thromboplastin time. Viscoelastic parameters showed an elevated maximum amplitude and low lysis at 30 minutes.
The investigators reported the following:
- A complete lack of lysis of clot at 30 minutes was seen in 57% of patients and predicted venous thromboembolism with an area under the receiver operating characteristic (AUROC) of 0.742 (P = .021).
- A D-Dimer cutoff of 2,600 ng/ml predicted the need for dialysis with an AUROC of 0.779 (P = .005).
- Overall, patients with no lysis of clot at 30 minutes and a D-Dimer > 2,600 ng/ml had a rate of venous thromboembolism of 50% compared with 0% for patients with neither risk factor (P = .008) and had a hemodialysis rate of 80% compared with 14% (P = .004).
In the JACS abstract, the study concluded, “The findings showed that fibrinolysis shutdown, as evidenced by elevated D-Dimer and complete failure of clot lysis at 30 minutes on TEG, predicts thromboembolic events and need for hemodialysis in critically ill patients with COVID-19. Further clinical trials are required to ascertain the need for early therapeutic anticoagulation or fibrinolytic therapy to address this state of fibrinolysis shutdown.”