Systemic thromboemboli in patients with Covid-19 may result from paradoxical embolization

Patent Foramen Ovale-associated Stroke and COVID-19 Vaccination

Background: COVID-19 infection has been associated with paradoxical thromboembolism through a patent foramen ovale (PFO) and ischaemic stroke. Such events have not been reported after COVID-19 vaccination. The aim of the present study was to investigate PFO-associated stroke during the mass COVID-19 vaccination in Slovenia. Methods: This prospective study, conducted between 26 December 2020 and 31 March 2022, enrolled consecutive patients (≥18 years) with PFO-associated stroke referred for a percutaneous closure to a single interventional facility in Slovenia. Results: A total of 953,546 people aged between 18 and 70 years received at least one dose of a COVID-19 vaccine approved by the European Medicines Agency. Of the 28 patients presenting with PFO-associated stroke, 12 patients (42.9%) were vaccinated prior to the event, of whom nine were women and three were men, aged between 21 and 70 years. Stroke occurred within 35 days after vaccination in six patients (50%). Clinical presentation included motor dysphasia, paresis, vertigo, ataxia, paraesthesia, headache, diplopia and hemianopia. At hospital discharge, 11 patients (91.6%) had at least one residual ischaemic lesion. Conclusion: A temporal coincidence of COVID-19 vaccination and PFO-associated stroke has been described. A potential cause–effect relationship may only be hypothesised.

OUP accepted manuscript

The course of COVID-19 patients may be complicated by thromboembolic events. We report on a 48-year-old female COVID-19 patient who underwent surgical removal of a large intracardiac thrombus. As per our centre protocol, critically ill COVID-19 patients are anticoagulated by the direct thrombin inhibitor Argatroban with close monitoring of anti-IIa activity. An intra-atrial thrombus formation fixed in a patent foramen ovale but also large mobile portions in both atria was diagnosed 4 days after weaning and removal of the jugular and femoral extracorporeal membrane oxygenation cannulas. The thrombus was removed surgically via median sternotomy and on cardiopulmonary bypass. The thrombus had a bizarre appearance with several finger-like appendices, and histological analysis revealed a mixed picture of acute and chronic thrombus portions. This case highlights the risk of life-threatening thrombus formation in COVID-19 patients despite therapeutic thrombin inhibition.

Incidental diagnosis of a large cardiac thrombus swinging through an interatrial communication in a COVID-19 patient: Case report and literature review

Introduction

The hypercoagulability state induced by COVID-19 has been well established and various forms of subsequent thromboembolic events have been reported throughout literature including multiple cases of intracardiac thrombi, four of which in our center alone, this case being the fifth.

Case report

We report the case of a 38-year-old male with no prior cardiovascular history who -subsequently to a COVID-19 infection-developped a right atrial thrombosis associated to a pulmonary embolism, and in whom cardiography revealed an interatrial communication. Management relied upon curative doses of low molecular weight heparin (LMWH) with favourable outcome.

Discussion

In our discussion, we lay out the various physiopathological mechanisms incriminated throughout literature in the genesis of a hypercoagulability state distinctive of COVID-19, before highlighting the incidence of an interatrial communication (whether a Potent Foramen Ovale or Atrial Septal Defect) discovered in patients with COVID-19, and the potential paradoxical embolization risks they imply as well as reported cases. A mention of hemostatic parameters monitored was also warranted. Finally we discuss the guidelines in terms of prophylactic and therapeutic anticoagulation in hospitalized patients before discussing cardiac thrombosis's therapeutic options.

Conclusion

Our case highlights various key points which could change the prognosis of COVID-19 patients, whether related to the underdiagnosis of interatrial abnormalities or with regards to the diagnosis to thromboembolic events, but also the indisputable place of anticoagulation in COVID-19 management.

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Thromboembolic events complicating COVID-19 have been well described and are attributed to a hypercoagulability state distinctive of COVID-19.

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A pre-existing Potent Foramen Ovale (PFO) or Atrial septal Defect (ASD) in COVID-19 patients is unknown as only a handful of studies covered the subject.

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The association of a cardiac thrombosis with a pulmonary embolism and interatrial communication exposes patients to risks of paradoxical embolization and subsequent arterial thrombotic events.

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Prophylactic and curatrive anticoagulation is unrefutably a key pillar in the management of COVID-19.