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The first cases of large vessel arterial occlusion stroke linked to the AstraZeneca COVID-19 vaccine have been described in the UK.
All three cases (including one fatal) occurred in two women and a man in his 30s or 40s and involved blockages of the carotid artery and middle cerebral artery. Two of the three patients also had venous thrombosis involving the portal and cerebral venous system. All three also had extremely low platelet counts, confirmed antibodies to platelet factor 4, and increased D-dimer rate, all characteristics of the vaccine-induced immune thrombotic thrombocytopenia (VITT) reaction associated with the AstraZeneca vaccine.
They are described in detail in a letter published online May 25 in the Journal of Neurology, Neurosurgery and Psychiatry.
“These are the first detailed reports of arterial stroke thought to be caused by VITT after the AstraZeneca COVID vaccine, although stroke was previously mentioned in the VITT data,” commented lead author David Werring, PhD, FRCP . Medscape Medical News.
“VITT more commonly presented as CVST [Cerebral venous sinus thrombosis] which is a stroke caused by venous thrombosis; these cases show that it can also cause stroke caused by arterial thrombosis, âexplained Werring, who is professor of clinical neurology at the Stroke Research Center, University College London Queen Square Institute of Neurology, UK.
“In patients with Ischemic stroke, especially younger patients, and who have received the AstraZeneca vaccine within the last month, clinicians should consider VITT as a possible cause, as there is specific treatment needed for this syndrome, âhe said. .
Young patients with ischemic stroke after receiving the AstraZeneca vaccine should be urgently evaluated for VITT with laboratory tests, including platelet count, D-dimers, fibrinogen, and anti-PF4 antibodies, write the authors, then managed by a multidisciplinary team including hematology, neurology, stroke, neurosurgery, neuroradiology, for rapid access to treatments including intravenous immunoglobulin, methylprednisolone, plasmapheresis and non-heparic anticoagulants such as fondaparinux, argatroban, or direct oral anticoagulants.
Werring noted that these reports add nothing to the overall risk / benefit of the vaccine, as they only describe three cases.
âAlthough VITT is very serious, the benefits of the vaccine still outweigh its risks,â he said. âAbout 40% of patients hospitalized with COVID-19 suffer from some kind of thrombosis and about 1.5% have ischemic stroke. While the latest UK figures put the incidence of VITT with the AstraZeneca vaccine at 1 in 50,000 to 1 in 100,000.
“Our report does not suggest that VITT is more common than these latest figures estimate, but we are simply calling attention to an alternative presentation,” he added.
The first patient in the current case series, a woman in her 30s, suffered a headache on the right side and around his eyes 6 days after the vaccine. Five days later, she woke up drowsy and weak in her left face, arm and leg.
Imaging revealed a blocked right middle cerebral artery with a cerebral infarction and clots in the right portal vein. She underwent brain surgery to reduce pressure in her skull, collect and replace plasma, and received the anticoagulant, fondaparinux, but sadly died.
The second patient, a woman in her 30s, presented with headache, confusion, weakness in her left arm and loss of vision on her left side 12 days after receiving the vaccine. Imaging showed occlusion of both carotid arteries, as well as pulmonary embolism and a left cerebral venous sinus thrombosis.
Her platelet count increased after plasma removal and replacement and intravenous corticosteroid therapy, and her condition improved after treatment with fondaparinux.
The third patient, a man in his early forties, presented 3 weeks after receiving his vaccination with speech problems. Imaging showed a clot in the left middle cerebral artery, but there was no sign of clots in the cerebral venous sinuses. He received a platelet and plasma transfusion as well as fondaparinux and remains stable.
In one related comment, Hugh Markus, PhD, FRCP, Professor of Stroke Medicine at the University of Cambridge, UK, writes: âThis report highlights that immune-mediated coagulopathy can also cause arterial thrombosis, including stroke. ischemic, although venous thrombosis and in particular cerebral venous sinus thrombosis appear more common.
âDuring the current COVID vaccination period, a high index of suspicion is necessary to identify thrombotic episodes following vaccination,â he adds. “However, it is important to remember that these side effects are rare and much less common than cerebral venous thrombosis and ischemic strokes associated with the COVID-19 infection itself.”
Several experts who commented on these reports for the Science Media Center all agreed with Werring and Markus that these reports do not change the current risk / benefit estimates with the vaccine.
Ian Douglas, PhD, Professor of Pharmacoepidemiology, London School of Hygiene & Tropical Medicine, UK, who sits on the UK Medicines and Health Products Regulatory Agency Pharmacovigilance Expert Advisory Group, said: low platelet count associated with AstraZeneca vaccine is increasingly clear. So far, the cases described have tended to involve venous clots such as cerebral venous thrombosis. In this series of three case reports, we now have evidence that the types of blood vessels affected include arteries as well as veins. ”
“It is important to stress that such cases remain very rare, and it is certainly much rarer in people who have received the AstraZeneca vaccine than in people affected by COVID-19 itself,” said Douglas.
“The description of the cases suggests that the patients involved had the same type of symptoms as those already described in the cases of cerebral venous thrombosis, and they do not suggest that patients should be vigilant for something different,” he added. .
âHowever, the emergence of details like this will help guide healthcare professionals who may face similar cases in the future; the sooner these cases are recognized, the more likely they are to quickly receive the right kind of treatment, which will hopefully lead to better results. “
Will Lester, MBChB, PhD, consultant hematologist, University Hospitals Birmingham NHS Foundation Trust, said: âVITT remains a rare complication, and patients with a history of thrombosis, including stroke, should not consider themselves. as presenting a higher risk of this type. of rare thrombosis after vaccination, and COVID infection itself is a significant risk of stroke and other types of thrombosis.
Many countries have suspended use of the AstraZeneca vaccine due to its link to VITT syndrome or have limited its use to older people because the VITT reaction appears to be slightly more common in younger people. In the UK, the current recommendation is that people under 40 should be offered an alternative to the AstraZeneca vaccine when possible.