Is COVID-19 an Independent Risk Factor for Heparin-Induced Thrombocytopenia?

Significance of heparin induced thrombocytopenia (HIT) in COVID-19: a systematic review and meta-analysis

Heparin-induced thrombocytopenia (HIT) occurs in approximately 3% of patients receiving heparinoids. About 30-75% of patients with type 2 of HIT develop thrombosis as a result of platelet activation. The most important clinical symptom is thrombocytopenia. Patients with severe COVID-19 are among those receiving heparinoids. This meta-analysis performed to picture the current knowledge and results of published studies in this field. Three search engines were searched and 575 papers were found. After evaluation, 37 articles were finally selected of which 13 studies were quantitatively analyzed. The pooled frequency rate of suspected cases with HIT in 13 studies with 11,241 patients was 1.7%. The frequency of HIT was 8.2% in the extracorporeal membrane oxygenation subgroup with 268 patients and 0.8% in the hospitalization subgroup with 10,887 patients. The coincidence of these two conditions may increase the risk of thrombosis. Of the 37 patients with COVID-19 and confirmed HIT, 30 patients (81%) were treated in the intensive care unit or had severe COVID-19. The most commonly used anticoagulants were UFH in 22 cases (59.4%). The median platelet count before treatment was 237 (176-290) x 10³/µl and the median nadir platelet count was 52 (31-90.5) x 10³/µl.

Ischemic Stroke Due to Heparin-induced Thrombocytopenia during Severe COVID-19 Infection

A 53-year-old woman with severe coronavirus disease 2019 (COVID-19) pneumonia was admitted and treated with intravenous unfractionated heparin for thromboprophylaxis under general anesthesia with mechanical ventilation. She developed right hemiparesis after hospitalization due to a large hemorrhagic infarction. Her platelet count decreased from 243,000/μL at administration to 121,000/μL. Anti-platelet factor 4-heparin antibody testing was positive according to a latex immunoturbidimetric assay. She was therefore diagnosed with heparin-induced thrombocytopenia. We immediately stopped the heparin and started argatroban; the platelet count recovered, and thrombosis did not relapse. Physicians should consider heparin-induced thrombocytopenia as a cause of ischemic stroke in patients with COVID-19 infection.

A rare case of intracerebral hemorrhage complicating heparin-induced thrombocytopenia in a COVID-19 patient

Introduction

Heparin-induced thrombocytopenia is a rare complication of heparin therapy associated with thrombocytopenia and mainly thrombotic complications.

Case report

we herein describe a case of a woman hospitalized for management of a severe case of COVID-19 treated with low molecular weight heparin, who developed heparin-induced thrombocytopenia complicated by intracerebral hemorrhage with no thrombotic complications.

Conclusion

Discontinuation of heparin was effective without the use of other non-heparin anticoagulants, platelet transfusion or plasmapheresis.

•

HIT is a rare complication of LMWH, it is associated with thrombocytopenia and mainly thrombotic complications.

•

In this paper we will report a rare complication of HIT : ICH in a 63 years old woman admitted for covid 19-infection.

•

Discontinuation of heparin was effective without the use of other non-heparin anticoagulants, platelet transfusion or plasmapheresis.

Heparin-induced thrombocytopenia in patients with COVID-19: a systematic review and meta-analysis

Heparin thromboprophylaxis is routinely administered during hospitalization for COVID-19. Because of the immune stimulation related to COVID-19, there is ongoing concern regarding a heightened incidence of heparin-induced thrombocytopenia (HIT). We performed a literature search using PubMed, EMBASE, Cochrane, and medRxiv database to identify studies that reported clinical and laboratory characteristics and/or the incidence of HIT in patients with COVID-19. The primary aim was to systematically review the clinical features and outcomes of patients with COVID-19 with confirmed HIT. The secondary objective was to perform a meta-analysis to estimate the incidence of HIT in hospitalized patients with COVID-19. A meta-analysis of 7 studies including 5849 patients revealed the pooled incidence of HIT in COVID-19 of 0.8% (95% confidence interval [CI], 0.2%-3.2%; I² = 89%). The estimated incidences were 1.2% (95% CI, 0.3%-3.9%; I² = 65%) vs 0.1% (95% CI, 0.0%-0.4%; I² = 0%) in therapeutic vs prophylactic heparin subgroups, respectively. The pooled incidences of HIT were higher in critically ill patients with COVID-19 (2.2%; 95% CI, 0.6%-8.3%; I² = 72.5%) compared with noncritically ill patients (0.1%; 95% CI, 0.0%-0.4%: I² = 0%). There were 19 cases of confirmed HIT and 1 with autoimmune HIT for clinical and laboratory characterization. The median time from heparin initiation to HIT diagnosis was 13.5 days (interquartile range, 10.75-16.25 days). Twelve (63%) developed thromboembolism after heparin therapy. In conclusion, the incidence of HIT in patients with COVID-19 was comparable to patients without COVID-19, with higher incidences with therapeutic anticoagulation and in critically ill patients.

Untangling the Intricacies of Infection, Thrombosis, Vaccination, and Antiphospholipid Antibodies for COVID-19

Advanced SARS-CoV-2 infections not uncommonly associate with the occurrence of silent or manifest thrombotic events which may be found as focal or systemic disease. Given the potential complexity of COVID-19 illnesses, a multifactorial causation is likely, but several studies have focused on infection-induced coagulopathy. Procoagulant states are commonly found in association with the finding of antiphospholipid antibodies. The correlation of the latter with thrombosis and/or clinical severity remains controversial. Although measures of antiphospholipid antibodies most commonly include assessments for lupus anticoagulant, anticardiolipin, and anti-ß2-glycoprotein-I antibodies, lesser common antibodies have been detected, and there remains speculation that other yet undiscovered autoimmune thrombotic events may yet be found. The recent discovery of post-vaccination thromboses associated with platelet factor 4 antibody has created another level of concern. The pathogenesis of antiphospholipid antibodies and their role in COVID-19-related thrombosis deserves further attention. The multifactorial nature of thrombosis associated with both infection and vaccination should continue to be studied as new events unfold. Even if a cause-and-effect relationship is variable at best, such dedicated research is likely to generate other valuable insights that are applicable to medicine generally.

Is the heparin-induced thrombocytopenia-like syndrome associated with ChAdOx vaccine related to the vaccine itself or to an autoimmune reaction to severe acute respiratory syndrome 2 coronavirus: insights and implications from previous reports in infected cases?

Prothrombotic states, similar to heparin-induced thrombocytopenia (HIT) in recipients of the ChAdOx vaccine, sounded alarm bells internationally. Equivalent episodes of HIT were detailed in several case reports of coronavirus disease 2019. This suggests a common pathogenesis and warrants a shift in the management of implicated cases.

Thrombocytopenia and Intracranial Venous Sinus Thrombosis after "COVID-19 Vaccine AstraZeneca" Exposure

Background: As of 8 April 2021, a total of 2.9 million people have died with or from the coronavirus infection causing COVID-19 (Corona Virus Disease 2019). On 29 January 2021, the European Medicines Agency (EMA) approved a COVID-19 vaccine developed by Oxford University and AstraZeneca (AZD1222, ChAdOx1 nCoV-19, COVID-19 vaccine AstraZeneca, Vaxzevria, Covishield). While the vaccine prevents severe course of and death from COVID-19, the observation of pulmonary, abdominal, and intracranial venous thromboembolic events has raised concerns. Objective: To describe the clinical manifestations and the concerning management of patients with cranial venous sinus thrombosis following first exposure to the “COVID-19 vaccine AstraZeneca”. Methods: Patient files, laboratory findings, and diagnostic imaging results, and endovascular interventions of three concerning patients were evaluated in retrospect. Results: Three women with intracranial venous sinus thrombosis after their first vaccination with “COVID-19 vaccine AstraZeneca” were encountered. Patient #1 was 22 years old and developed headaches four days after the vaccination. On day 7, she experienced a generalized epileptic seizure. Patient #2 was 46 years old. She presented with severe headaches, hemianopia to the right, and mild aphasia 13 days after the vaccination. MRI showed a left occipital intracerebral hemorrhage. Patient #3 was 36 years old and presented 17 days after the vaccination with acute somnolence and right-hand hemiparesis. The three patients were diagnosed with extensive venous sinus thrombosis. They were managed by heparinization and endovascular recanalization of their venous sinuses. They shared similar findings: elevated levels of D-dimers, platelet factor 4 antiplatelet antibodies, corona spike protein antibodies, combined with thrombocytopenia. Under treatment with low-molecular-weight heparin, platelet counts normalized within several days. Conclusion: Early observations insinuate that the exposure to the “COVID-19 vaccine AstraZeneca” might trigger the expression of antiplatelet antibodies, resulting in a condition with thrombocytopenia and venous thrombotic events (e.g., intracranial venous sinus thrombosis). These patients’ treatment should address the thrombo-embolic manifestations, the coagulation disorder, and the underlying immunological phenomena.