Age-Stratified Risk of Cerebral Venous Sinus Thrombosis After SARS-CoV-2 Vaccination

Update on management of cerebral venous thrombosis

PURPOSE OF REVIEW

This review intends to systematize the diagnostic and treatment approach to cerebral venous thrombosis (CVT), highlighting key studies that have been recently published.

RECENT FINDINGS

In light of the recent pandemic, new risk factors for CVT have emerged. Contrast-enhanced MRI and susceptibility-weighted imaging have been shown to offer increased sensitivity for detecting cortical vein thrombosis.Dabigatran seems to be as effective and well tolerated as warfarin for long-term anticoagulation. Partial venous recanalization often occurs in patients treated with anticoagulation only, as early as 8 days after treatment onset. For patients with CVT and impending brain herniation, two-thirds of those who undergo decompressive craniectomy survive, with one-third being functionally independent 6 months after diagnosis.

SUMMARY

CVT is an unusual type of cerebrovascular disease that mostly affects women of fertile age. Risk factors should be identified and addressed. Diagnosis relies on confirmation of venous sinus and/or vein thrombosis, usually by CT venography or MRI. Anticoagulation is the cornerstone of treatment. Despite the lack of high-quality evidence, endovascular treatment is often considered in severe cases. Special populations require tailored approaches. About 80% achieve mRS 0-1, but residual symptoms often affect quality of life and the ability to return to work.

Cerebral venous thrombosis: a practical review

The evolution of the Coronavirus Disease-2019 pandemic and its vaccination raised more attention to cerebral venous thrombosis (CVT). Although CVT is less prevalent than arterial stroke, it results in larger years of life lost. CVT is more common in women and young patients. Predisposing factors are categorized as transient factors such as pregnancy, puerperium, oral contraceptive pills, trauma, and dehydration; and permanent factors such as neoplastic, vasculitic, thrombophilic, hematologic conditions, infectious causes such as severe acute respiratory syndrome coronavirus-2 infection and HIV. The most common manifestations are headache, seizures, focal neurologic deficits, altered level of consciousness, and cranial nerve palsies. The most common syndromes are stroke-like, raised-intracranial-pressure (ICP), isolated-headache, and encephalopathy, which may have overlaps. Diagnosis is mostly based on computed tomography, magnetic resonance imaging, and their respective venous sequences, supported by blood results abnormalities such as D-dimer elevation. Treatment includes the prevention of propagation of current thrombus with anticoagulation (heparin, or low molecular weight heparinoids and then warfarin, or direct oral anticoagulants), decreasing ICP (even by decompressive craniotomy), and treatment of specific underlying diseases.

Sex differences in cerebral venous sinus thrombosis after adenoviral vaccination against COVID-19

INTRODUCTION

Cerebral venous sinus thrombosis associated with vaccine-induced immune thrombotic thrombocytopenia (CVST-VITT) is a severe disease with high mortality. There are few data on sex differences in CVST-VITT. The aim of our study was to investigate the differences in presentation, treatment, clinical course, complications, and outcome of CVST-VITT between women and men.

PATIENTS AND METHODS

We used data from an ongoing international registry on CVST-VITT. VITT was diagnosed according to the Pavord criteria. We compared the characteristics of CVST-VITT in women and men.

RESULTS

Of 133 patients with possible, probable, or definite CVST-VITT, 102 (77%) were women. Women were slightly younger [median age 42 (IQR 28-54) vs 45 (28-56)], presented more often with coma (26% vs 10%) and had a lower platelet count at presentation [median (IQR) 50x109/L (28-79) vs 68 (30-125)] than men. The nadir platelet count was lower in women [median (IQR) 34 (19-62) vs 53 (20-92)]. More women received endovascular treatment than men (15% vs 6%). Rates of treatment with intravenous immunoglobulins were similar (63% vs 66%), as were new venous thromboembolic events (14% vs 14%) and major bleeding complications (30% vs 20%). Rates of good functional outcome (modified Rankin Scale 0-2, 42% vs 45%) and in-hospital death (39% vs 41%) did not differ.

DISCUSSION AND CONCLUSIONS

Three quarters of CVST-VITT patients in this study were women. Women were more severely affected at presentation, but clinical course and outcome did not differ between women and men. VITT-specific treatments were overall similar, but more women received endovascular treatment.

Cerebral venous sinus thrombosis due to vaccine-induced immune thrombotic thrombocytopenia in middle-income countries

BACKGROUND

Adenovirus-based COVID-19 vaccines are extensively used in low- and middle-income countries (LMICs). Remarkably, cases of cerebral venous sinus thrombosis due to vaccine-induced immune thrombotic thrombocytopenia (CVST-VITT) have rarely been reported from LMICs.

AIMS

We studied the frequency, manifestations, treatment, and outcomes of CVST-VITT in LMICs.

METHODS

We report data from an international registry on CVST after COVID-19 vaccination. VITT was classified according to the Pavord criteria. We compared CVST-VITT cases from LMICs to cases from high-income countries (HICs).

RESULTS

Until August 2022, 228 CVST cases were reported, of which 63 were from LMICs (all middle-income countries [MICs]: Brazil, China, India, Iran, Mexico, Pakistan, Turkey). Of these 63, 32 (51%) met the VITT criteria, compared to 103 of 165 (62%) from HICs. Only 5 of the 32 (16%) CVST-VITT cases from MICs had definite VITT, mostly because anti-platelet factor 4 antibodies were often not tested. The median age was 26 (interquartile range [IQR] 20-37) versus 47 (IQR 32-58) years, and the proportion of women was 25 of 32 (78%) versus 77 of 103 (75%) in MICs versus HICs, respectively. Patients from MICs were diagnosed later than patients from HICs (1/32 [3%] vs. 65/103 [63%] diagnosed before May 2021). Clinical manifestations, including intracranial hemorrhage, were largely similar as was intravenous immunoglobulin use. In-hospital mortality was lower in MICs (7/31 [23%, 95% confidence interval (CI) 11-40]) than in HICs (44/102 [43%, 95% CI 34-53], p = 0.039).

CONCLUSIONS

The number of CVST-VITT cases reported from LMICs was small despite the widespread use of adenoviral vaccines. Clinical manifestations and treatment of CVST-VITT cases were largely similar in MICs and HICs, while mortality was lower in patients from MICs.

Risk of Thrombosis Following the First Dose of ChAdOx1 nCoV-19 Vaccine in Patients Undergoing Maintenance Hemodialysis: A Self-Controlled Case Series Study

Background

The ChAdOx1 nCoV-19 vaccine is associated with vaccine-induced thrombosis and thrombocytopenia (VITT). Patients with end-stage renal disease (ESRD) under hemodialysis are at elevated risk of heparin-induced thrombocytopenia, which shares similar mechanisms with VITT. We aimed to examine the risk of VITT after the first dose of ChAdOx1 nCoV-19 vaccine using a self-controlled case series analysis (SCCS) in the hemodialyzed ESRD population.

Methods

Drawing from the largest multi-center electronic medical records database in Taiwan, we identified adult patients, with or without hemodialysis, between 1st December, 2020, and 31st December, 2021, who received a first dose of ChAdOx1 nCoV-19 vaccine and had an outcome of thrombocytopenia, venous thrombosis, or arterial thrombosis. We calculated the incident rate ratios (IRRs) of outcomes in different periods at risk, compared to periods not at risk.

Results

 We identified 59 hemodialysis patients and 41 non-dialysis patients with an outcome. The SCCS analyses showed, for the hemodialysis group, a significantly increased risk of outcomes during the period 31 to 60 days post-exposure to ChAdOx1 nCoV-19 vaccine (IRR: 2.823; 95% CI: 1.423-5.600). However, in non-dialysis patients there was no increase in risks during any of the post-exposure risk periods.

Conclusion

For ESRD patients under hemodialysis, the first dose of ChAdOx1 nCoV-19 vaccine was associated with a 2.8-fold increase in risk of thrombosis.

Thrombocytopenic, thromboembolic and haemorrhagic events following second dose with BNT162b2 and ChAdOx1: self-controlled case series analysis of the English national sentinel cohort

Background

Thrombosis associated with thrombocytopenia was a matter of concern post first and second doses of BNT162b2 and ChAdOx1 COVID-19 vaccines. Therefore, it is important to investigate the risk of thrombocytopenic, thromboembolic and haemorrhagic events following a second dose of BNT162b2 and ChAdOx1 COVID-19 vaccines.

Methods

We conducted a large-scale self-controlled case series analysis, using routine primary care data linked to hospital data, among 12.3 million individuals (16 years old and above) in England. We used the nationally representative Oxford-Royal College of General Practitioners (RCGP) sentinel network database with baseline and risk periods between 8th December 2020 and 11th June 2022. We included individuals who received two vaccine (primary) doses of the BNT162b2 mRNA (Pfizer-BioNTech) and two vaccine doses of ChAdOx1 nCoV-19 (Oxford-AstraZeneca) vaccines in our analyses. We carried out a self-controlled case series (SCCS) analysis for each outcome using a conditional Poisson regression model with an offset for the length of risk period. We reported the incidence rate ratios (IRRs) and 95% confidence intervals (CI) of thrombocytopenic, thromboembolic (including arterial and venous events) and haemorrhagic events, in the period of 0-27 days after receiving a second dose of BNT162b2 or ChAdOx1 vaccines compared to the baseline period (14 or more days prior to first dose, 28 or more days after the second dose and the time between 28 or more days after the first and 14 or more days prior to the second dose). We adjusted for a range of potential confounders, including age, sex, comorbidities and deprivation.

Findings

Between December 8, 2020 and February 11, 2022, 6,306,306 individuals were vaccinated with two doses of BNT162b2 and 6,046,785 individuals were vaccinated with two doses of ChAdOx1. Compared to the baseline, our analysis show no increased risk of venous thromboembolic events (VTE) for both BNT162b2 (IRR 0.71, 95% CI: 0.65-0.770) and ChAdOx1 (IRR 0.91, 95% CI: 0.84-0.98); and similarly there was no increased risk for cerebral venous sinus thrombosis (CVST) for both BNT162b2 (IRR 0.87, 95% CI: 0.41-1.85) and ChAdOx1 (IRR 1.73, 95% CI: 0.82-3.68). We additionally report no difference in IRR for pulmonary embolus, and deep vein thrombosis, thrombocytopenia, including idiopathic thrombocytopenic purpura (ITP), and haemorrhagic events post second dose for both BNT162b2.

Interpretation

Reassuringly, we found no associations between increased risk of thrombocytopenic, thromboembolic and haemorrhagic events post vaccination with second dose for either of these vaccines.

Funding

Data and Connectivity: COVID-19 Vaccines Pharmacovigilance study.

Neurological Disorders following COVID-19 Vaccination

Nowadays, people all over the world have been receiving different types of coronavirus disease 2019 (COVID-19) vaccines. While their effectiveness has been well recognized, various post-vaccination disorders are not fully understood. In this review, we discuss neurological disorders related to vascular, immune, infectious, and functional factors following COVID-19 vaccination, and attempt to provide neuroscientists, psychiatrists, and vaccination staff with a reference for the diagnosis and treatment of these diseases. These disorders may present as a recurrence of previous neurological disorders or new-onset diseases. Their incidence rate, host and vaccine characteristics, clinical manifestations, treatment, and prognosis differ significantly. The pathogenesis of many of them remains unclear, and further studies are needed to provide more evidence. The incidence rate of severe neurological disorders is relatively low, most of which are reversible or treatable. Therefore, the benefits of vaccination outweigh the risk of COVID-19 infection, especially among fragile populations.

Diagnosis and Treatment of Cerebral Venous Thrombosis

OBJECTIVE

Cerebral venous thrombosis (CVT), thrombosis of the dural sinus, cerebral veins, or both, is a rare cerebrovascular disease. Although mortality rates after CVT have declined over time, this condition can result in devastating neurologic outcomes. This article reviews the latest literature regarding CVT epidemiology, details new factors associated with the development of CVT, and describes advances in CVT treatment. It also contains a discussion of future directions in the field, including novel diagnostic imaging modalities, and potential strategies to reduce the risks associated with CVT.

LATEST DEVELOPMENTS

The incidence of CVT may be as high as 2 per 100,000 adults per year. It remains a difficult condition to diagnose given its variable clinical manifestations and the necessity of neuroimaging for confirmation. The COVID-19 pandemic has revealed a novel CVT trigger, vaccine-induced immune thrombotic thrombocytopenia (VITT), as well as an association between COVID-19 infection and CVT. Although VITT is a very rare event, timely diagnosis and treatment of CVT due to VITT likely improves patient outcomes. Direct oral anticoagulants are currently being used to treat CVT and emerging data suggest that these agents are as safe and effective as vitamin K antagonists. The role of endovascular therapy to treat CVT, despite a recent clinical trial, remains unproven.

ESSENTIAL POINTS

The incidence of CVT has increased, outcomes have improved, and the use of direct oral anticoagulants to treat CVT represents an important advance in the clinical care of these patients. Rates of CVT as a complication of COVID-19 vaccines using adenoviral vectors are very low (<5 per million vaccine doses administered), with the benefits of COVID-19 vaccination far outweighing the risks.

Incidence of sinus thrombosis with thrombocytopenia-A nation-wide register study

Safe vaccination is essential for mitigation of the COVID-19 pandemic. Two adenoviral vector vaccines, ChAdOx1 nCov-19 (AstraZeneca) and Ad26.COV2.S (Johnson&Johnson/Janssen) have shown to be effective and they are distributed globally, but reports on serious cerebral venous sinus thrombosis (CVST) associated with thrombocytopenia, have emerged. Our objective was to evaluate the background incidence of CVST with thrombocytopenia and to compare it to incidences following COVID-19 vaccines. We conducted a register-based nation-wide cohort study in Finland, including all 5.5 million individuals alive in Finland, 1 Jan 2020. COVID-19 vaccinations registered in the National Vaccination Register served as the exposure. We detected CVST admissions or hospital visits recorded in the hospital discharge register from Jan 1, 2020 through April 2, 2021. We confirmed the diagnosis of CVST and thrombocytopenia (platelet count <150,000 per cubic millimeter) using radiology reports and laboratory data. By Poisson regression, we compared the baseline incidences to the risks within four weeks after COVID-19 vaccinations. Out of the 167 CVST episodes identified in the registers, 117 were confirmed as CVST, 18 of which coincided with thrombocytopenia (baseline incidence 0.18 per 28 days per million persons). We found 2 episodes of CVST with thrombocytopenia within 28 days of the first ChAdOx1 nCov-19 vaccination (among 200,397 vaccinated, aged 16 or above). No cases were found following the first mRNA vaccine dose among 782,604 vaccinated. The background incidence of CVST combined with thrombocytopenia was minuscule compared to the incidence during the weeks following the ChAdOx1 nCov-19 vaccination. Accurate estimation of the baseline incidence is essential in the critical appraisal of the benefit-risk of any vaccination program.

Vaccine Vigilance System: Considerations on the Effectiveness of Vigilance Data Use in COVID-19 Vaccination

(1) Background: The safety of medicines has been receiving increased attention to ensure that the risks of taking medicines do not outweigh the benefits. This is the reason why, over several decades, the pharmacovigilance system has been developed. The post-authorization pharmacovigilance system is based on reports from healthcare professionals and patients on observed adverse reactions. The reports are collected in databases and progressively evaluated. However, there are emerging concerns about the effectiveness of the established passive pharmacovigilance system in accelerating circumstances, such as the COVID-19 pandemic, when billions of doses of new vaccines were administered without a long history of use. Currently, health professionals receive fragmented new information on the safety of medicines from competent authorities after a lengthy evaluation process. Simultaneously, in the context of accelerated mass vaccination, health professionals need to have access to operational information-at least on organ systems at higher risk. Therefore, the aim of this study was to perform a primary data analysis of publicly available data on suspected COVID-19 vaccine-related adverse reactions in Europe, in order to identify the predominant groups of reported medical conditions after vaccination and their association with vaccine groups, as well as to evaluate the data accessibility on specific syndromes. (2) Methods: To achieve the objectives, the data publicly available in the EudraVigilance European Database for Suspected Adverse Drug Reaction Reports were analyzed. The following tasks were defined to: (1) Identify the predominant groups of medical conditions mentioned in adverse reaction reports; (2) determine the relative frequency of reports within vaccine groups; (3) assess the feasibility of obtaining information on a possibly associated syndrome-myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). (3) Results: The data obtained demonstrate that the predominant medical conditions induced after vaccination are relevant to the following categories: (1) "General disorders and administration site conditions", (2) "nervous system disorders", and (3) "musculoskeletal and connective tissue disorders". There are more reports for mRNA vaccines, but the relative frequency of reports per dose administered, is lower for this group of vaccines. Information on ME/CFS was not available, but reports of "chronic fatigue syndrome" are included in the database and accessible for primary analysis. (4) Conclusions: The information obtained on the predominantly reported medical conditions and the relevant vaccine groups may be useful for health professionals, patients, researchers, and medicine manufacturers. Policymakers could benefit from reflecting on the design of an active pharmacovigilance model, making full use of modern information technologies, including big data analysis of social media and networks for the detection of primary signals and building an early warning system.

Outcomes of Cerebral Venous Thrombosis due to Vaccine-Induced Immune Thrombotic Thrombocytopenia After the Acute Phase

BACKGROUND

Cerebral venous thrombosis (CVT) due to vaccine-induced immune thrombotic thrombocytopenia (VITT) is a severe condition, with high in-hospital mortality rates. Here, we report clinical outcomes of patients with CVT-VITT after SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) vaccination who survived initial hospitalization.

METHODS

We used data from an international registry of patients who developed CVT within 28 days of SARS-CoV-2 vaccination, collected until February 10, 2022. VITT diagnosis was classified based on the Pavord criteria. Outcomes were mortality, functional independence (modified Rankin Scale score 0-2), VITT relapse, new thrombosis, and bleeding events (all after discharge from initial hospitalization).

RESULTS

Of 107 CVT-VITT cases, 43 (40%) died during initial hospitalization. Of the remaining 64 patients, follow-up data were available for 60 (94%) patients (37 definite VITT, 9 probable VITT, and 14 possible VITT). Median age was 40 years and 45/60 (75%) patients were women. Median follow-up time was 150 days (interquartile range, 94-194). Two patients died during follow-up (3% [95% CI, 1%-11%). Functional independence was achieved by 53/60 (88% [95% CI, 78%-94%]) patients. No new venous or arterial thrombotic events were reported. One patient developed a major bleeding during follow-up (fatal intracerebral bleed).

CONCLUSIONS

In contrast to the high mortality of CVT-VITT in the acute phase, mortality among patients who survived the initial hospitalization was low, new thrombotic events did not occur, and bleeding events were rare. Approximately 9 out of 10 CVT-VITT patients who survived the acute phase were functionally independent at follow-up.

Should patients with epilepsy be vaccinated against coronavirus disease 2019? A systematic review and meta-analysis

OBJECTIVE

The coronavirus disease 2019 (COVID-19) vaccination coverage, willingness, and safety profiles in patients with epilepsy remain poorly understood. We aimed to summarize the available evidence of COVID-19 vaccination coverage, willingness, and safety profiles among patients with epilepsy.

METHODS

We performed a literature search in the Pubmed, EMBASE, and Cochrane Central Register database between 1 January 2020 and 30 April 2022. We included eligible studies that provided information on the COVID-19 vaccination coverage, willingness, and safety profiles among patients with epilepsy. We investigated the association between baseline characteristics of patients with epilepsy and unvaccination status using a fixed-effect model. We calculated the pooled overall willingness to be vaccinated against COVID-19. We systematically reviewed the safety profiles after COVID-19 vaccination in patients with epilepsy.

RESULTS

Ten eligible observational studies and two case reports yielded 2589 participants with epilepsy or their caregivers. Among 2145 participants that provided the information of vaccination status, 1508 (70.3%) patients with epilepsy were not administered COVID-19 vaccine, and 58% (95%CI 40-75%) of respondents were willing to be vaccinated against COVID-19. Seizure status (active versus inactive, OR 1.84 95%CI 1.41-2.39, I² = 0%) rather than seizure type (focal versus non-focal, OR 1.22 95%CI 0.94-1.58, I² = 0%) was associated with COVID-19 unvaccination status. Vaccines were well-tolerated; epilepsy-related problems such as increase in seizure frequency and status epilepticus after COVID-19 vaccination were uncommon.

CONCLUSIONS

Our findings suggest a low COVID-19 vaccination coverage and willingness in patients with epilepsy. Vaccination against COVID-19 appears to be well-tolerated and safe in patients with epilepsy, supporting a positive outlook toward vaccination in this population.

High Incidence and Unique Features of Cerebral Venous Sinus Thrombosis in Hospitalized Patients With COVID-19 Infection

Cerebral venous sinus thrombosis (CVST) secondary to vaccine-induced thrombotic thrombocytopenia is an extremely rare side effect of adenovirus-based COVID-19 vaccines. CVST incidence associated with COVID-19 itself has not been widely reported. We report the incidence of CVST in patients hospitalized with COVID-19 during the first year of the pandemic.

Meaningful use of imaging resources to rule out cerebral venous sinus thrombosis after ChAdOx1 COVID-19 vaccination: Evaluation of the AHA diagnostic algorithm with a clinical cohort and a systematic data review

Vaccine-induced immune thrombotic thrombocytopenia (VITT) with cerebral venous thrombosis (CVST) is an improbable (0.0005%), however potentially lethal complication after ChAdOx1 vaccination. On the other hand, headache is among the most frequent side effects of ChAdOx1 (29.3%). In September 2021, the American Heart Association (AHA) suggested a diagnostic workflow to facilitate risk-adapted use of imaging resources for patients with neurological symptoms after ChAdOx1. We aimed to evaluate the AHA workflow in a retrospective patient cohort presenting at four primary care hospitals in Germany for neurological complaints after ChAdOx1. Scientific literature was screened for case reports of VITT with CVST after ChAdOx1, published until September 1st, 2021. One-hundred-thirteen consecutive patients (77 female, mean age 38.7 +/− 11.9 years) were evaluated at our institutes, including one case of VITT with CVST. Further 228 case reports of VITT with CVST are published in recent literature, which share thrombocytopenia (225/227 reported) and elevated d-dimer levels (100/101 reported). The AHA workflow would have recognized all VITT cases with CVST (100% sensitivity), the number needed to diagnose (NND) was 1:113. Initial evaluation of thrombocytopenia or elevated d-dimer levels would have lowered the NND to 1:68, without cost of sensitivity. Hence, we suggest that in case of normal thrombocyte and d-dimer levels, the access to further diagnostics should be limited by the established clinical considerations regardless of vaccination history.

Ad26.COV2.S Vaccine-Induced Thrombocytopenia Leading to Dural Sinus Thrombosis and Intracranial Hemorrhage Requiring Hemicraniectomy: A Case Report and Systematic Review

The coronavirus disease 2019 (COVID-19) pandemic has claimed nearly 5.5 million lives worldwide. Adenovirus-based vaccines are safe and effective, but they are rarely associated with vaccine-induced thrombosis and thrombocytopenia (VITT) as well as cerebral venous sinus thrombosis (CVST). We conducted a systematic literature search of intracerebral hemorrhage (ICH) secondary to CVST associated with VITT from the Ad26.COV2.S vaccine, and we present the first case of this pathology in the reviewed literature of a patient who required neurosurgical decompression. The systematic literature review was completed on December 19, 2021, by searching PubMed and Ovid for articles with primary data on CVST associated with VITT following the Ad26.COV2.S vaccine. We also specifically searched for cases that required neurosurgical intervention. Articles were independently screened by two authors, and both secondary and tertiary searches were done as well. Descriptive statistics were collected and presented in table form. Nine studies were identified that met inclusion criteria. There were no cases identified of patients who underwent neurosurgical decompression after developing this pathology. We thus present the first case in the reviewed literature of a patient who developed ICH after receiving the Ad26.COV2.S vaccine and underwent decompressive hemicraniectomy. Despite severe thrombocytopenia and prolonged intensive care, the patient was discharged to neurorehabilitation. There is a much greater risk of CVST and ICH during COVID-19 infections than from the vaccines. However, as booster vaccines are approved and widely distributed, it is critical to make prompt, accurate diagnoses of this vaccine-related complication and consider neurosurgical decompression.

Management of Cerebral Venous Thrombosis Due to Adenoviral COVID-19 Vaccination

Objective

Cerebral venous thrombosis (CVT) caused by vaccine‐induced immune thrombotic thrombocytopenia (VITT) is a rare adverse effect of adenovirus‐based severe acute respiratory syndrome‐coronavirus 2 (SARS‐CoV‐2) vaccines. In March 2021, after autoimmune pathogenesis of VITT was discovered, treatment recommendations were developed. These comprised immunomodulation, non‐heparin anticoagulants, and avoidance of platelet transfusion. The aim of this study was to evaluate adherence to these recommendations and its association with mortality.

Methods

We used data from an international prospective registry of patients with CVT after the adenovirus‐based SARS‐CoV‐2 vaccination. We analyzed possible, probable, or definite VITT‐CVT cases included until January 18, 2022. Immunomodulation entailed administration of intravenous immunoglobulins and/or plasmapheresis.

Results

Ninety‐nine patients with VITT‐CVT from 71 hospitals in 17 countries were analyzed. Five of 38 (13%), 11 of 24 (46%), and 28 of 37 (76%) of the patients diagnosed in March, April, and from May onward, respectively, were treated in‐line with VITT recommendations (p < 0.001). Overall, treatment according to recommendations had no statistically significant influence on mortality (14/44 [32%] vs 29/55 [52%], adjusted odds ratio [OR] = 0.43, 95% confidence interval [CI] = 0.16–1.19). However, patients who received immunomodulation had lower mortality (19/65 [29%] vs 24/34 [70%], adjusted OR = 0.19, 95% CI = 0.06–0.58). Treatment with non‐heparin anticoagulants instead of heparins was not associated with lower mortality (17/51 [33%] vs 13/35 [37%], adjusted OR = 0.70, 95% CI = 0.24–2.04). Mortality was also not significantly influenced by platelet transfusion (17/27 [63%] vs 26/72 [36%], adjusted OR = 2.19, 95% CI = 0.74–6.54).

Conclusions

In patients with VITT‐CVT, adherence to VITT treatment recommendations improved over time. Immunomodulation seems crucial for reducing mortality of VITT‐CVT. ANN NEUROL 2022;92:562–573

Cerebral venous thrombosis due to vaccine-induced immune thrombotic thrombocytopenia after a second ChAdOx1 nCoV-19 dose

Vaccine-induced immune thrombotic thrombocytopenia (VITT), a rare but life-threatening complication of adenoviral vaccination against COVID-19, has been reported almost entirely following the first dose. Krzywicka and colleagues report on 124 patients with VITT in a multinational registry diagnosed after dose 2; no specific events were observed after dose 1. These patients had early presentation, and two of the patients died.