Dataset Information

Thrombosis patterns and clinical outcome of COVID-19 vaccine-induced immune thrombotic thrombocytopenia: A Systematic Review and Meta-Analysis.

ABSTRACT:

Objectives

To meta-analyse the clinical manifestations, diagnosis, treatment, and mortality of vaccine-induced immune thrombotic thrombocytopenia (VITT) after adenoviral vector vaccination.

Methods

Eighteen studies of VITT after ChAdOx1 nCoV-19 or Ad26.COV2.S vaccine administration were reviewed from PubMed, Scopus, Embase, and Web of Science. The meta-analysis estimated the summary effects and between-study heterogeneity regarding the incidence, manifestations, sites of thrombosis, diagnostic findings, and clinical outcomes.

Results

The incidence of total venous thrombosis after ChAdOx1 nCoV-19 vaccination was 28 (95% CI 12-52, I²=100%) per 100,000 doses administered. Of 664 patients included in the quantitative analysis (10 studies), the mean age of patients with VITT was 45.6 years (95% CI 43.8-47.4, I²=57%), with a female predominance (70%). Cerebral venous thrombosis (CVT), deep vein thrombosis (DVT)/pulmonary thromboembolism (PE), and splanchnic vein thrombosis occurred in 54%, 36%, and 19% of patients with VITT, respectively. The pooled incidence rate of CVT after ChAdOx1 nCoV-19 vaccination (23 per 100,000 person-years) was higher than that reported in the pre-pandemic general population (0.9 per 100,000 person-years). Intracranial haemorrhage and extracranial thrombosis accompanied 47% and 33% of all patients with CVT, respectively. The antiplatelet factor 4 antibody positivity rate was 91% (95% CI 88-94, I²=0%) and the overall mortality was 32% (95% CI 24-41, I²=69%), and no significant difference was observed between heparin- and non-heparin-based anticoagulation treatments (risk ratio 0.84, 95% CI 0.47-1.50, I²=0%).

Conclusions

Patients with VITT after SARS-CoV-2 vaccination most frequently presented with CVT following DVT/PE and splanchnic vein thrombosis, and about one-third of patients had a fatal outcome. This meta-analysis should provide a better understanding of VITT and assist clinicians in identifying VITT early to improve outcomes and optimise management.

SUBMITTER: Kim AY

PROVIDER: S-EPMC8942584 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:In the spring of 2021, reports of rare and unusual venous thrombosis in association with the ChAdOx1 and Ad26.COV2.S adenovirus-based coronavirus vaccines led to a brief suspension of their use by several countries. Thromboses in the cerebral and splanchnic veins among patients vaccinated in the preceding 4 weeks were described in 17 patients out of 7.98 million recipients of the Ad26.COV2.S vaccine (with 3 fatalities related to cerebral vein thrombosis) and 169 cases of cerebral vein thrombosis among 35 million ChAdOx1 recipients. Events were associated with thrombocytopenia and anti-PF4 (antibodies directed against platelet factor 4), leading to the designation vaccine-induced immune thrombotic thrombocytopenia. Unlike the related heparin-induced thrombotic thrombocytopenia, with an estimated incidence of <1:1000 patients treated with heparin, and a mortality rate of 25%, vaccine-induced immune thrombotic thrombocytopenia has been reported in 1:150 000 ChAdOx1 recipients and 1:470 000 Ad26.COV.2 recipients, with a reported mortality rate of 20% to 30%. Early recognition of this complication should prompt testing for anti-PF4 antibodies and acute treatment targeting the autoimmune and prothrombotic processes. Intravenous immunoglobulin (1 g/kg for 2 days), consideration of plasma exchange, and nonheparin anticoagulation (argatroban, fondaparinux) are recommended. In cases of cerebral vein thrombosis, one should monitor for and treat the known complications of venous congestion as they would in patients without vaccine-induced immune thrombotic thrombocytopenia. Now that the Ad26.COV2.S has been reapproved for use in several countries, it remains a critical component of our pharmacological armamentarium in stopping the spread of the human coronavirus and should be strongly recommended to patients. At this time, the patient and community-level benefits of these two adenoviral vaccines vastly outweigh the rare but serious risks of vaccination. Due to the relatively low risk of severe coronavirus disease 2019 (COVID-19) in young women (<50 years), it is reasonable to recommend an alternative vaccine if one is available. Ongoing postmarketing observational studies are important for tracking new vaccine-induced immune thrombotic thrombocytopenia cases and other rare side effects of these emergent interventions.