VITT

 Q: Patients developing severe thrombosis after the COVID-19 vaccine should be treated with heparin?

A) True

B) False

Answer: B

Vaccine-induced thrombotic thrombocytopenia (VITT) has been reported after the COVID-19 vaccine, particularly after adenovirus-based COVID-19 vaccines. This condition should be treated as Heparin-Induced Thrombocytopenia (HIT). Although there is no exposure to heparin clinical behavior is the same. Moreover, there are reports that patients deteriorate after receiving heparin in VITT. In these patients, it would be prudent to do anticoagulation only with non-heparin agents. In severe cases, intravenous immune globulin (IVIG) should be considered early in the case. 

Another important aspect is to follow the fibrinogen level. if it is below 100, consideration should be given to transfuse via blood product or synthetic version of fibrinogen. Alike all HIT patients, platelet transfusions should be avoided unless the bleeding is life-threatening. A hematologist should be on board to guide these unfortunate complex patients.

#COVID-19

#hematology

References:

1. Greinacher A, Thiele T, Warkentin TE, et al. Thrombotic Thrombocytopenia after ChAdOx1 nCov-19 Vaccination. N Engl J Med 2021. 

2. https://www.hematology.org/covid-19/vaccine-induced-immune-thrombotic-thrombocytopenia (Accessed on May 6, 2021). 

3. https://b-s-h.org.uk/media/19530/guidance-version-13-on-mngmt-of-thrombosis-with-thrombocytopenia-occurring-after-c-19-vaccine_20210407.pdf (Accessed on May 6, 2021).