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Updated: Dec 16, 2025

Leveraging Turbidity and Thromboelastography for Complementary Clot Characterization
Published on: June 4, 2020
Thromboelastography Profiles of Critically Ill Patients With Coronavirus Disease 2019
Eugene Yuriditsky1, James M Horowitz1, Cristian Merchan2
1Leon H. Charney Division of Cardiology, Department of Medicine, NYU Langone Health, New York, NY.
Insights
Critically ill COVID-19 patients often show hypercoagulable states, indicated by thromboelastography. While common, these coagulation changes did not correlate with thromboembolic events in this study.
Area of Science:
- Critical Care Medicine
- Hematology
- Infectious Diseases
Background:
- Patients with coronavirus disease 2019 (COVID-19) experience a high rate of thromboembolic events.
- Identifying patients at highest risk for these events remains challenging due to a lack of robust predictive methods.
Purpose of the Study:
- To characterize the coagulation status of critically ill COVID-19 patients using thromboelastography.
- To investigate potential correlations between thromboelastography parameters and thromboembolic events in this population.
Main Methods:
- Retrospective review of 64 critically ill COVID-19 patients admitted to a tertiary ICU.
- Thromboelastography was performed to assess coagulation parameters.
- Analysis included clotting index, reaction time, K values, alpha angle, and maximum amplitude.
Main Results:
- Fifty percent of patients exhibited a hypercoagulable clotting index (>3).
- A significant proportion showed hypercoagulable profiles with rapid clot formation (α angle) and increased clot strength (maximum amplitude).
- Thromboelastography parameters did not correlate with observed thromboembolic events, though elevated D-dimer correlated with shorter reaction times.
Conclusions:
- Critically ill COVID-19 patients frequently present with hypercoagulable thromboelastography profiles.
- Derangements in fibrinogen and platelet function are common.
- Further research, including platelet aggregation studies, is warranted to understand these coagulation abnormalities.
Objectives:
The rate of thromboembolic events among patients with coronavirus disease 2019 is high; however, there is no robust method to identify those at greatest risk. We reviewed thromboelastography studies in critically ill patients with coronavirus disease 2019 to characterize their coagulation states.
Design:
Retrospective.
Setting:
Tertiary ICU in New York City.
Patients:
Sixty-four patients with coronavirus disease 2019 admitted to the ICU with thromboelastography performed.
Interventions:
None.
Measurements And Main Results:
Fifty percent of patients had a clotting index in the hypercoagulable range (clotting index > 3) (median 3.05). Reaction time and K values were below the lower limit of normal in 43.8% of the population consistent with a hypercoagulable profile. The median α angle and maximum amplitude (75.8° and 72.8 mm, respectively) were in the hypercoagulable range. The α angle was above reference range in 70.3% of patients indicative of rapid clot formation. Maximum amplitude, a factor of fibrinogen and platelet count and function, and a measure of clot strength was above reference range in 60.1% of patients. Thirty-one percent had thromboembolic events; thromboelastography parameters did not correlate with events in our cohort. Those with D-dimer values greater than 2,000 were more likely to have shorter reaction times compared with those with D-dimer levels less than or equal to 2,000 (4.8 vs 5.6 min; p = 0.001).
Conclusions:
A large proportion of critically ill patients with coronavirus disease 2019 have hypercoagulable thromboelastography profiles with additional derangements related to fibrinogen and platelet function. As the majority of patients have an elevated thromboelastography maximum amplitude, a follow-up study evaluating platelet aggregation would be instructive.
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