ABSTRACT
Recent reports have highlighted rare, and sometimes fatal, cases of cerebral venous sinus thrombosis (CVST) and thrombocytopenia following the Vaxzevria vaccine. An underlying immunological mechanism similar to that of spontaneous heparin-induced thrombocytopenia (HIT) is suspected, with the identification of antibodies to platelet factor-4 (PF4), but without previous heparin exposure. This unusual mechanism has significant implications for the management approach used, which differs from usual treatment of CVST. We describe the cases of two young males, who developed severe thrombocytopenia and fatal CVST following the first dose of Vaxzevria. Both presented with a headache, with subsequent rapid neurological deterioration. One patient underwent PF4 antibody testing, which was positive. A rapid vaccination programme is essential in helping to control the COVID-19 pandemic. Hence, it is vital that such COVID-19 vaccine-associated events, which at this stage appear to be very rare, are viewed through this lens. However, some cases have proved fatal. It is critical that clinicians are alerted to the emergence of such events to facilitate appropriate management. Patients presenting with CVST features and thrombocytopenia post-vaccination should undergo PF4 antibody testing and be managed in a similar fashion to HIT, in particular avoiding heparin and platelet transfusions.
Subject(s)
COVID-19 , Sinus Thrombosis, Intracranial , Thrombocytopenia , Anticoagulants , COVID-19 Vaccines , Humans , Male , Pandemics , SARS-CoV-2 , Thrombocytopenia/chemically induced , United Kingdom , Vaccination/adverse effectsSubject(s)
Anticoagulants/therapeutic use , COVID-19/complications , Drug Substitution/methods , Pandemics , Pyridines/therapeutic use , Rivaroxaban/therapeutic use , SARS-CoV-2 , Thiazoles/therapeutic use , Thrombophilia/drug therapy , Warfarin/therapeutic use , Administration, Oral , Anticoagulants/adverse effects , COVID-19/blood , COVID-19/epidemiology , COVID-19/prevention & control , Counseling , Drug Monitoring , Hospitals, University/organization & administration , Hospitals, University/statistics & numerical data , Humans , Informed Consent , London/epidemiology , Patient Acceptance of Health Care , Patient Education as Topic , Pyridines/adverse effects , Quarantine , Rivaroxaban/adverse effects , Telemedicine , Tertiary Care Centers/organization & administration , Tertiary Care Centers/statistics & numerical data , Thiazoles/adverse effects , Thrombophilia/etiologyABSTRACT
The association of severe coronavirus disease 2019 (COVID-19) with an increased risk of venous thromboembolism (VTE) has resulted in specific guidelines for its prevention and management. The VTE risk appears highest in those with critical care admission. The need for postdischarge thromboprophylaxis remains controversial, which is reflected in conflicting expert guideline recommendations. Our local protocol provides thromboprophylaxis to COVID-19 patients during admission only. We report postdischarge VTE data from an ongoing quality improvement program incorporating root-cause analysis of hospital-associated VTE (HA-VTE). Following 1877 hospital discharges associated with COVID-19, 9 episodes of HA-VTE were diagnosed within 42 days, giving a postdischarge rate of 4.8 per 1000 discharges. Over 2019, following 18 159 discharges associated with a medical admission; there were 56 episodes of HA-VTE within 42 days (3.1 per 1000 discharges). The odds ratio for postdischarge HA-VTE associated with COVID-19 compared with 2019 was 1.6 (95% confidence interval, 0.77-3.1). COVID-19 hospitalization does not appear to increase the risk of postdischarge HA-VTE compared with hospitalization with other acute medical illness. Given that the risk-benefit ratio of postdischarge thromboprophylaxis remains uncertain, randomized controlled trials to evaluate the role of continuing thromboprophylaxis in COVID-19 patients following hospital discharge are required.