Subacute stent thrombosis in a patient with COVID-19 pneumonia

Purinergic signaling: decoding its role in COVID-19 pathogenesis and promising treatment strategies

The pathogenesis of coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2), is complex and involves dysregulated immune responses, inflammation, and coagulopathy. Purinergic signaling, mediated by extracellular nucleotides and nucleosides, has emerged as a significant player in the pathogenesis of COVID-19. Extracellular adenosine triphosphate (ATP), released from damaged or infected cells, is a danger signal triggering immune responses. It activates immune cells, releasing pro-inflammatory cytokines, contributing to the cytokine storm observed in severe COVID-19 cases. ATP also promotes platelet activation and thrombus formation, contributing to the hypercoagulability seen in COVID-19 patients. On the other hand, adenosine, an immunosuppressive nucleoside, can impair anti-viral immune responses and promote tissue damage through its anti-inflammatory effects. Modulating purinergic receptors represents a promising therapeutic strategy for COVID-19. Understanding the role of purinergic signaling in COVID-19 pathogenesis and developing targeted therapeutic approaches can potentially improve patient outcomes. This review focuses on the part of purinergic signaling in COVID-19 pathogenesis and highlights potential therapeutic approaches targeting purinergic receptors.

In-stent Thrombosis and COVID-19 Infection: Current Insights on the Mechanistic Relationship

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been demonstrated as a major risk factor in inducing coronary stent thrombosis due to its propensity to create a pro-thrombotic state. This review explores the mechanisms that may contribute to the increased thrombosis risk seen in COVID-19. Furthermore, we discuss the patient and haematological factors that predispose to an increased risk of stent thrombosis, as well as the role of certain antiplatelet and anticoagulation therapies, including ticagrelor and enoxaparin, that may reduce the likelihood and severity of in-stent thrombosis, in SARS-CoV-2 infection. To counter the proinflammatory and pro-thrombotic state shown in COVID-19, anti-thrombotic therapy in the future may be optimised using point-of-care platelet inhibition testing and inflammation-modifying therapies. Large-scale randomised trials with long-term follow-up are increasingly necessary to assess the intersection of COVID-19 and stent optimisation as well as the reduction of stent thrombosis after drug-eluting stent (DES) implantation.

Double Whammy: Subacute Stent Thrombosis While Being Adherent to Dual Antiplatelet Therapy Including Ticagrelor, Followed by Multiple Coronary Artery Aneurysms in a COVID-19 Patient

Coronavirus disease 2019 (COVID-19), although predominantly a respiratory illness, can have important cardiovascular implications, which include the development of myocardial injury/myocarditis, acute coronary syndromes, arrhythmias, pericarditis, and the occurrence of arterial and venous thrombosis. We describe a rare case of a middle-aged COVID-19 patient who developed sub-acute stent thrombosis after implantation of second-generation drug-eluting stents (DES) despite being adherent to dual antiplatelet therapy including ticagrelor and who subsequently developed multiple coronary artery aneurysms within a few weeks of the DES implantation.

Effects of Simulated COVID-19 Cytokine Storm on Stent Thrombogenicity

BACKGROUND

Cytokine storm-related hypercoagulation may be important in the pathogenesis of stent thrombosis in patients with SARS-CoV-2. Whether stent polymers behave differently under such conditions has never been explored.

METHODS

Fluorinated polymer-nanocoated and uncoated COBRA stents (CeloNova), BioLinx-polymer-coated Resolute Onyx stents (Medtronic), and Synergy stents (Boston Scientific), which are abluminally coated with a bioabsorbable polymer, were exposed to human blood from healthy donors which was supplemented with 400 pg/mL IL-6 and 100 pg/mL TNF-α, similar to what is seen in cytokine storm caused by SARS-CoV-2. Platelet adhesion and neutrophil activation, assessed by immunofluorescence, were compared under cytokine storm and control conditions (untreated blood) (n = 4 experimental runs).

RESULTS

Platelet adhesion values, defined as %platelet-covered area x staining intensity, were significantly lower in coated and uncoated COBRA and in Resolute Onyx than in Synergy under control conditions (1.28 × 107 ± 0.43 × 107 vs. 2.92 × 107 ± 0.49 × 107 vs. 3.57 × 107 ± 0.73 × 107 vs. 9.94 × 107 ± 0.99 × 107; p ≤0.0001). In cytokine storm, platelet adhesion values remained low in coated COBRA-PzF (1.78 × 107 ± 0.38 × 107) compared to all other devices (uncoated COBRA: 5.92 × 107 ± 0.96 × 107; Resolute Onyx: 7.27 × 107 ± 1.82 × 107; Synergy: 11.28 × 107 ± 1.08 × 107; p ≤ 0.0001). Although cytokine storm conditions significantly increased neutrophil activation in all stents, it was significantly less in coated and uncoated COBRA, and in Resolute Onyx than in Synergy.

CONCLUSIONS

Blood-biomaterials interactions may determine the thrombogenic potential of stents. Under simulated cytokine storm conditions, fluoropolymer-coated stents showed the most favorable anti-thrombogenic and anti-inflammatory properties.

Very late stent thrombosis associated with COVID-19 infection: a case report and review of the literature

Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2 has varied manifestation with multisystem involvement. Acute coronary syndrome in COVID-19 as a result of stent thrombosis is an uncommon entity and is often due to hypercoagulable state. A 40-year-old male was referred to us with acute onset chest pain. He also reported fever, sore throat and dry cough for six days which mandated testing for COVID-19 which turned out to be positive. He had a prior history of coronary artery disease with a drug eluting stent implanted two years back. An electrocardiogram was suggestive of acute anterior wall myocardial infarction while echocardiogram revealed hypokinesia of left anterior descending (LAD) artery territory. Coronary angiogram revealed non-occlusive thrombus in proximal LAD stent. A Thrombolysis in Myocardial Infarction (TIMI) III flow was restored following balloon angioplasty with a non-compliant balloon and use of glycoprotein (GP) IIb-IIIa receptor antagonist. A diagnosis of very late stent thrombosis subsequent to COVID-19 was made.