COVID-19’s dangerous connection to coagulopathy

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As researchers and physicians learn more about COVID-19, it's become clear that coagulopathy is among its most severe complications.

In a recent "Answers From the Lab" podcast, Nahla Heikal, M.D., a clinical pathologist in Mayo Clinic's Department of Laboratory Medicine and Pathology and co-director of Mayo's Special Coagulation Laboratory, explains the seriousness of the coagulopathy COVID-19 can trigger.

"COVID-19 has two major pathological elements: deteriorating lung function and thrombosis. This makes coagulopathy one of the most significant poor prognostic features," Dr. Heikal says. "Coagulopathy in COVID-19 patients shows complex engagement of many aspects of the hemostatic system, with abnormal platelet activation, alteration of the fibrinolytic system, and strong activation of the endothelium that cause persistent endotheliitis, with a wide spectrum of thrombosis reported, either venous or arterial. In addition to macrothrombi, microthombi can also develop, mainly in the lungs."

Nahla Heikal, M.D.

Coagulopathy in COVID-19 patients is an example of sepsis-associated coagulopathy that can develop from various infectious agents as a result of the body's activation of the coagulation and immune systems in response to the virus. In some cases, this can lead to the development of disseminated intravascular coagulation, or DIC — a serious condition characterized by widespread blood clot formation throughout the body that may cause organ damage. Interestingly, however, patients with COVID-19 usually do not progress to overt DIC.

Due to the potential severity of COVID-related coagulopathy, prompt laboratory testing is crucial for proper management. The laboratory test D-dimer can be particularly useful.

"Markedly elevated D-dimer is one of the predictors of mortality in patients with severe COVID-19," Dr. Heikal says. "Therefore, hospital admission should be considered even in the absence of other severe symptoms, since elevated D-dimer clearly signifies increased thrombin generation."

Those test results can have a significant impact on patient care. In COVID-19 patients who have elevated D-dimer, a prophylactic dose of low molecular weight heparin or unfractionated heparin is recommended. If results worsen, consideration should be given to using experimental therapies.

"The information about coagulopathy and COVID-19 patients is still evolving," Dr. Heikal says. "The clinical and scientific communities have a lot of work to do to better understand this disease and answer a lot of unanswered questions."

She continues: "For example, what is the role of platelet activation? Is there an increased risk of heparin-induced thrombocytopenia? Is COVID coagulopathy in the spectrum of antiphospholipid syndrome? Why do a majority of patients not progress to DIC? Whether using our standard laboratory testing or novel tools, there are great opportunities for new discoveries that will expand our knowledge."

"Answers From the Lab" is a Mayo Clinic podcast that explores knowledge and advances in laboratory science. Recent episodes have featured a wide range of topics related to COVID-19, including testing, prevention, immunity, and screening. You can listen and subscribe on Apple Podcasts, or wherever you get your podcasts.

Tracy Will

Tracy Will is a senior marketing specialist at Mayo Clinic Laboratories where she covers innovation, specialty testing, and advances in laboratory medicine. Tracy has worked at Mayo Clinic since 2016.