Abstract
Background: Venous thromboembolism (VTE)—including deep vein thrombosis, pulmonary embolism, and cerebral venous sinus thrombosis (CVST)—may occur early after vaccination against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We sought to describe the site, clinical characteristics, and outcomes of VTE after vaccination against SARS-CoV-2. Methods: In a prospective study using the Registro Informatizado de Enfermedad TromboEmbólica (RIETE) platform, patients with VTE 4–30 days after vaccination against SARS-CoV-2 (1 February 2021 through 30 April 2021) were included. VTE patients recruited from the same centers into RIETE in the same months in 2018–2019 were selected as the reference group. All-cause mortality and major bleeding were the main study outcomes. Results: As of 30 April 2020, 102 patients with post-vaccination VTEs had been identified (28 after adenovirus-based vaccination [ChAdOx1 nCov-19; AstraZeneca] and 74 after mRNA-based vaccination [mRNA-1273; Moderna, and BNT162b2; Pfizer]). Compared with 911 historical controls, patients with VTE after adenovirus-based vaccination more frequently had CVST (10.7% vs. 0.4%, p < 0.001) or thrombosis at multiple sites (17.9% vs. 1.3%, p < 0.001), more frequently had thrombocytopenia (40.7% vs. 14.7%, p < 0.001), and had higher 14-day mortality (14.3% vs. 0.7%; odds ratio [OR]: 25.1; 95% confidence interval [CI]: 6.7–94.9) and major bleeding rates (10.3% vs. 1.0%, OR: 12.03, 95% CI: 3.07–47.13). The site of thrombosis, accompanying thrombocytopenia, and 14-day mortality rates were not significantly different for patients with VTE after mRNA-based vaccination, compared with historical controls. Conclusions: Compared with historical controls, VTE after adenovirus-based vaccination against SARS-CoV-2 is accompanied by thrombocytopenia, occurs in unusual sites, and is associated with worse clinical outcomes.
Highlights
COVID-19 has resulted in substantial mortality and morbidity around the world [1].Respiratory distress and thrombotic events- venous thromboembolism (VTE)—are among the major concern in these patients [2–5]
This report based on an international study found several key distinctions in presenting features and clinical outcomes in patients with Venous thromboembolism (VTE) after vaccination against SARS-CoV2, compared with historical controls
Thrombocytopenia at presentation was more frequently observed in patients with adenovirus-based vaccination but not those with mRNA-based vaccination, compared with historical controls
Summary
COVID-19 has resulted in substantial mortality and morbidity around the world [1].Respiratory distress and thrombotic events- venous thromboembolism (VTE)—are among the major concern in these patients [2–5]. Some of the cases of thrombosis occurred in unusual sites such as cerebral venous sinus thrombosis (CVST) and splanchnic vein thrombosis ([SVT], including portal, hepatic, mesenteric, renal, and gonadal veins) These events were reported mostly in women of childbearing age, associated with thrombocytopenia and antibodies against platelet factor-4 (PF-4), referred to as vaccine-induced thrombotic thrombocytopenia (VITT) [10–15,19]. This issue has caused concern among the public, clinicians, and policy-makers, with restrictions or pauses being implemented for the use of adenovirus-based SARS-CoV-2 vaccines [11,20]. Compared with 911 historical controls, patients with VTE after adenovirus-based vaccination more frequently had CVST (10.7% vs. 0.4%, p < 0.001) or thrombosis at multiple sites (17.9% vs. 1.3%, p < 0.001), more frequently had thrombocytopenia (40.7% vs. 14.7%, p < 0.001), and had higher 14-day mortality
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