NICE develops new COVID-19 rapid guideline to manage vaccine-induced clotting conditions

Thrombocytopenia is a condition where a person has a low platelet count, while thrombosis is the formation of blood clots. Although extremely rare, with only 14.2 cases occurring per million doses of the COVID-19 vaccine, this condition can be very serious and requires swift diagnosis and urgent treatment.

The guideline recommends that healthcare staff refer people with suspected VITT who are acutely unwell to the emergency department immediately. If the person is not acutely unwell and results can be obtained and reviewed on the same day, then a full blood count should be performed in primary care. If these blood tests show a low platelet count then the person should then be referred to the emergency department on the same day.

If blood tests indicate the person is unlikely to have VITT, then healthcare staff should discuss the signs and symptoms of VITT with them and provide advice on when and where to seek further medical attention if their symptoms persist or worsen. If a high clinical suspicion of VITT remain then they should consider repeating the full blood count after two to three days if symptoms worsen, or discuss further tests with a clinical haematologist.

VITT is confirmed using a test called an ELISA (enzyme-linked immunosorbent assay), that detects a certain antibody that people with VITT have called platelet factor 4 (PF4). However, if healthcare staff suspect that a patient has VITT they should start treatment in consultation with a haematologist without waiting for ELISA results.

If the person has developed thrombosis, healthcare staff should perform same-day imaging tests such as a CT scan to confirm where the blood clot is before starting treatment.

Dr Paul Chrisp, director of NICE's Centre for Guidelines, said: "Although VITT is a very rare condition, it's crucial that healthcare professionals feel supported and able to swiftly identify and treat the small number of people who do develop it.

"This is a living guideline, which can be continuously updated to incorporate the latest evidence and keep abreast of new developments.

"This guideline has not looked at the safety of COVID-19 vaccines; that is not NICE's remit and the data from the MHRA shows the benefits of COVID vaccines far outweigh the risks. NICE's role here is to provide the best advice to help clinicians treat patients in the rare instances where they do develop VITT."

The guideline recommends treatment options for people with VITT, including non-heparin anticoagulation drugs and surgical interventions to treat thrombosis. Patients should also initially receive intravenous immunoglobulin to treat the VITT immune response. The guideline recommends that a hematologist should be involved in decisions around starting or stopping treatments.

When discharged from the hospital, patients should continue to be monitored by the hematology department and advised what to do if their symptoms worsen.

As with the managing COVID-19 guideline, the VITT guideline has been developed and published in the MAGICapp platform, a global system that promotes evidence sharing from different guideline creators, therefore increasing the speed at which recommendations can be developed and the ease with which they can be updated