How to diagnose and treat rare blood clots associated with a COVID-19 vaccine
In recent months, multiple regulatory bodies have shared concerns that COVID-19 vaccines developed by AstraZeneca and Johnson & Johnson may be associated with a heightened risk of rare blood clots. New guidance from the American Heart Association (AHA) explores this topic at length, offering advice for physicians who may encounter such blood clots and emphasizing that all adults should still be vaccinated.
The recommendations, published in Stroke, focused on the condition behind these latest concerns: cerebral venous sinus thrombosis (CVST), an incredibly serious condition that actually affects the brain’s veins as opposed to its arteries. Patients have been reported to have CVST and a low blood platelet count, a condition referred to as thrombosis-thrombocytopenia syndrome (TTS). And when TTS is determined to be associated with a COVID-19 vaccine, specialists refer to it as a vaccine-induced immune thrombotic thrombocytopenia (VITT).
A primary point in the group’s analysis is that COVID-19 patients actually face a much greater risk of CVST than individuals who receive a COVID-19 vaccine.
“The public can be reassured by the CDC’s and FDA’s investigation and these statistics—the likelihood of developing CVST after a COVID-19 vaccine is extremely low,” Karen L. Furie, MD, lead author of the new guidance, said in a prepared statement from the AHA. “We urge all adults to receive any of the approved COVID-19 vaccines.”
Furie—who serves as the chief of neurology at Rhode Island Hospital, the Miriam Hospital and Bradley Hospital in Providence, Rhode Island—also noted that any patients with a suspected blood clot should be screened immediately and asked if they’ve recently received a COVID-19 vaccine.
“Patients who present with the symptoms of CVST or blood clots and who recently received the COVID-19 vaccine should be treated using non-heparin anticoagulants,” she said. “No heparin products in any dose should be given for suspected CVST, TTS or VITT. With the right treatment, most patients can have a full recovery after CVST, TTS or VITT.”
The new guidance also notes that MR imaging with a venogram or CT with a venogram can help with the detection and diagnosis of CVST. Blood work for these patients, meanwhile, should include a complete blood count, a platelet count, a peripheral smear, a prothrombin time, partial thromboplastin time, a fibrinogen test, a D-dimer test and a PF4 antibody ELISA test.
Anticoagulation treatment should be used to treat any confirmed cases of CVST, the group added, even if there is a secondary hemorrhage in the patient’s brain. Also, oral anticoagulants are acceptable once the patient’s platelet count returns to normal.
The guidance’s authors also wrote that all post-vaccine blood clots should be reported to the U.S. Department of Health and Human Services Vaccine Adverse Event Reporting System.
“We will need data and robust research on the people who did not develop blood clots after the vaccine, too, so that we can fully understand the molecular and cellular mechanisms underlying CVST related to COVID-19 infection or after vaccination,” Furie said in the same AHA statement.
Click here for the full guidance.
Michael has more than 18 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.