Dr. Piotr Ligocki, head of the Internal Medicine Clinic at the 10th Military Hospital with a Polyclinic in Bydgoszcz, emphasized in an interview with PAP that due to SARS-CoV-2’s strong prothrombotic action in the pulmonary circulation, administering low-molecular-weight heparins to COVID-19 patients with additional risk factors for thrombosis can reduce the risk of life-threatening complications such as pulmonary embolism, heart attack, or stroke.
“SARS-CoV-2 is the only known virus with such a potent prothrombotic effect in the small circulation, i.e., pulmonary. It induces microclots that contribute to the formation of large clots, leading to pulmonary embolism, which is very life-threatening,” said Dr. Piotr Ligocki.
Moreover, individuals with long-COVID and post-COVID syndromes maintain an increased risk of thrombotic complications, including heart attacks and ischemic strokes. This risk extends to young, healthy, and even athletic individuals, sometimes even children. Dr. Ligocki highlighted observations indicating that nearly every deceased COVID-19 patient showed an intensified risk of thrombosis during autopsies, confirming previous findings related to the causes of death in COVID-19 patients.
The exact mechanism behind SARS-CoV-2’s prothrombotic effect is not yet fully understood. Dr. Ligocki suggested that the virus binds to the ACE2 receptor, commonly present in the circulatory system, which regulates blood pressure. Additionally, SARS-CoV-2 triggers a generalized inflammatory state by increasing the concentration of proinflammatory cytokines such as interleukin 6 (IL-6). Inflammatory factors contribute to endothelial damage, paving the way for microclot formation and generalized thrombotic disease.
Due to the high risk of thromboembolic complications, it is recommended to administer low-molecular-weight heparins to hospitalized patients with severe COVID-19 during the acute phase of infection.
“We have been and still are administering either prophylactic or therapeutic doses of heparins, especially if we have additional risk factors for thrombosis beyond COVID-19. These factors include a history of thromboembolic incidents, obesity, where heparins must be given in a higher dose adjusted to body weight,” explained Dr. Ligocki.
He referred to observations indicating that patients receiving low-molecular-weight heparins in the hospital have a lower risk of prothrombotic complications. In some cases, patients treated with low-molecular-weight heparins also showed a lower incidence of long-COVID or post-COVID symptoms.
Dr. Ligocki emphasized that there are no recommendations to administer low-molecular-weight heparins to COVID-19 patients who are not hospitalized and are active at home. However, in his opinion, individuals with additional risk factors for thrombosis should use heparins preventively.
“For these patients, I recommend using prophylactic doses of heparins because it protects them from the prothrombotic action of the SARS-CoV-2 virus,” said Dr. Ligocki. He noted that these patients, however, have to bear the cost of heparins as they are not reimbursed.
The specialist also highlighted that COVID-19 patients who were hospitalized should have chest X-rays performed in the 1 to 3 months post-infection period to assess potential lung changes. Moreover, doctors should consider measuring D-dimer levels in the blood serum, especially in individuals with risk factors for thromboembolic diseases.
“Unfortunately, there are no similar recommendations for COVID-19 patients who were not hospitalized. However, I recommend that patients who experienced full-symptom COVID at home perform chest X-rays within 2-3 months after the illness and, in the presence of risk factors, measure D-dimer levels,” said Dr. Ligocki.
He added that the decision to start antithrombotic therapy based on D-dimer levels alone is not recommended. The risk of thrombosis needs to be individually assessed for each patient, taking into account the test results and risk factors. Based on this assessment, low-molecular-weight heparin therapy can be applied.