Unexplained arterial thrombosis: approach to diagnosis and treatment.

Arterial thrombotic events in younger patients without a readily apparent etiology present significant diagnostic and management challenges. We present a structured approach to diagnosis with consideration of common causes, including atherosclerosis and embolism, as well as uncommon causes, including medications and substances, vascular and anatomic abnormalities, systemic disorders, and thrombophilias. We highlight areas of management that have evolved within the past 5 years, including the use of dual-pathway inhibition in atherosclerotic disease, antithrombotic therapy selection in embolic stroke of undetermined source and left ventricular thrombus, the role of closure of patent foramen ovale for secondary stroke prevention, and the thrombotic potential of coronavirus disease 2019 infection and vaccination. We conclude with a representative case to illustrate the application of the diagnostic framework and discuss the importance of consideration of bleeding risk and patient preference in determining the appropriate management plan.

Early Triage of Cardioembolic Sources Using Chest Spectral Computed Tomography in Acute Ischemic Stroke.

OBJECTIVES: The present study investigated the potential usefulness of delayed-phase, low-dose, non-gated, chest spectral CT scans (DSCT) for the early triage of cardioembolic (CE) sources in patients admitted with acute ischemic stroke (AIS), and for the simultaneous detection of myocardial disease and thrombotic complications. MATERIAL AND METHODS: Since July 2020 and promoted by the COVID-19 pandemic, we implemented the use of DSCT after cerebrovascular CT angiography (CTA) among patients with AIS using a dual-layer spectral CT. We explored the presence of CE sources, as well as late myocardium iodine enhancement (LIE) and pulmonary thromboembolism. Among patients further undergoing transesophageal echocardiogram (TEE) or cardiac CTA, we explored the diagnostic performance. RESULTS: Fifty consecutive patients with AIS who underwent DSCT after cerebrovascular CTA comprised the patient population. The confidence degree for excluding cardiac thrombi was significantly higher than for LIE (4.4±0.8 vs. 3.4±1.3, p<0.0001). DSCT identified a CE source in 4 (8%) and LIE in 24 (48%) patients. The iodine ratio of CE sources was significantly lower compared to the left atrial appendage of patients with no CE sources (0.25±0.1 mg/mL vs. 0.91±0.2 mg/mL, p<0.0001). TEE/cardiac CT, performed in 20 (40%) patients, identified a CE source in 5 (25%) cases, whereas DSCT identified 4 (20%), leading to a sensitivity and specificity of 80% (95% CI 28-99%) and 100% (95% CI 78-100%) respectively (kappa 0.86). CONCLUSIONS: In this pilot study, we identified DSCT as a potential unsophisticated approach for the early triage of CE sources among patients with AIS undergoing CTA upon admission.

[COVID-19 from the Perspective of Haematology and Haemostaseology]. / COVID-19 aus Sicht der Hämatologie und Hämostaseologie.

Infection with SARS-COV-2 leads to a number of pathologies in the hematopoetic system that have significant impact on clinical symptoms and mortality. There are 3 stages of infection: (1) early upper respiratory tract infection with fever and lymphopenia (2) pulmonary phase and (3) hyperinflammatory phase with the clinical signs of organ failure such as ARDS/shock. Hyperinflammation, which is triggered by activation of T cells and monocytes/macrophages, is essential for organ pathologies. Interferon IFN-É£, tumor necrosis factor (TNF)-α, IL-10 and interleukin-6 (IL-6) play important roles as mediators of inflammation. In analogy to the cytokine release syndrome (CRS) after CAR-T cell therapy, the therapeutic activity of the IL-6 receptor antibody tocilizumab is investigated in clinical studies.The coagulation system is activated during the inflammatory phase of COVID infection, most likely on the pathophysiological basis of immune thrombosis. Clinically, there is a significantly increased incidence of venous (especially pulmonary artery embolism), but also arterial thromboembolism (TE). In laboratory chemistry, the D-dimer, fibrinogen but also vWF and FVIII are significantly increased. Guidelines for the prophylaxis and therapy of COVID-associated coagulopathy have been developed. Analogous to other viral infections, there are approaches to passive immunization using convalescent plasma. Its administration has shown promising activity in first uncontrolled case series and is currently being examined in clinical studies worldwide for its therapeutic activity.