Multimaterial decomposition in dual-energy CT for characterization of clots from acute ischemic stroke patients.

BACKGROUND: Nowadays, there is no method to quantitatively characterize the material composition of acute ischemic stroke thrombi prior to intervention, but dual-energy CT (DE-CT) offers imaging-based multimaterial decomposition. We retrospectively investigated the material composition of thrombi ex vivo using DE-CT with histological analysis as a reference. METHODS: Clots of 70 patients with acute ischemic stroke were extracted by mechanical thrombectomy and scanned ex vivo in formalin-filled tubes with DE-CT. Multimaterial decomposition in the three components, i.e., red blood cells (RBC), white blood cells (WBC), and fibrin/platelets (F/P), was performed and compared to histology (hematoxylin/eosin staining) as reference. Attenuation and effective Z values were assessed, and histological composition was compared to stroke etiology according to the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) criteria. RESULTS: Histological and imaging analysis showed the following correlation coefficients for RBC (r = 0.527, p < 0.001), WBC (r = 0.305, p = 0.020), and F/P (r = 0.525, p < 0.001). RBC-rich thrombi presented higher clot attenuation in Hounsfield units than F/P-rich thrombi (51 HU versus 42 HU, p < 0.01). In histological analysis, cardioembolic clots showed less RBC (40% versus 56%, p = 0.053) and more F/P (53% versus 36%, p = 0.024), similar to cryptogenic clots containing less RBC (34% versus 56%, p = 0.006) and more F/P (58% versus 36%, p = 0.003) than non-cardioembolic strokes. No difference was assessed for the mean WBC portions in all TOAST groups. CONCLUSIONS: DE-CT has the potential to quantitatively characterize the material composition of ischemic stroke thrombi. RELEVANCE STATEMENT: Using DE-CT, the composition of ischemic stroke thrombi can be determined. Knowledge of histological composition prior to intervention offers the opportunity to define personalized treatment strategies for each patient to accomplish faster recanalization and better clinical outcomes. KEY POINTS: • Acute ischemic stroke clots present different recanalization success according to histological composition. • Currently, no method can determine clot composition prior to intervention. • DE-CT allows quantitative material decomposition of thrombi ex vivo in red blood cells, white blood cells, and fibrin/platelets. • Histological clot composition differs between stroke etiology. • Insights into the histological composition in situ offer personalized treatment strategies.

Percutaneous Intervention of LVAD Outflow Graft Obstruction and Thrombosis.

Left ventricular assist devices serve as a salvage therapy for patients with advanced heart failure. Complications such as thrombosis and obstruction can lead to acute device malfunction, posing significant clinical risks. A multidisciplinary approach is crucial for management. Few cases in the literature have demonstrated the safety and efficacy of percutaneous intervention, which holds significant value due to its less invasive nature and minimal risk of morbidity, especially in high-risk surgical patients.

Revisión sistemática de los ensayos clínicos sobre terapia antitrombótica con inhibidores del factor XI / Systematic review of clinical trials on the antithrombotic therapy with factor XI inhibitors

Antecedentes y objetivo La información proveniente de los ensayos clínicos fase 2 sugiere que los inhibidores del factor XI podrían mostrar un perfil de eficacia/seguridad más favorable que las terapias antitrombóticas actuales. El objetivo de esta revisión sistemática es analizar la evidencia disponible derivada de esos estudios. Métodos Se realizó una búsqueda bibliográfica en las bases de datos PubMed, Cochrane Library, Scopus y EMBASE, y en las plataformas de registro de ensayos clínicos Clinical Trials y Cochrane Central Register of Controlled Trials. Los resultados se publicaron según la declaración PRISMA. Resultados Se identificaron un total de 18 ensayos clínicos concluidos o en curso abordando múltiples escenarios, incluyendo fibrilación auricular, ictus, infarto de miocardio y tromboembolismo venoso. Se analizó la evidencia procedente de 8 estudios con resultados disponibles. En general, los estudios fase 2 con inhibidores del factor XI mostraron un perfil adecuado de eficacia y seguridad. El balance beneficio/riesgo fue más favorable en términos de reducción de tromboembolismo venoso en pacientes sometidos a artroplastia total de rodilla. Para esta indicación, los inhibidores del factor XI mostraron una reducción global del 50% en la tasa de complicaciones trombóticas y del 60% en la tasa de hemorragias comparado con enoxaparina. En los estudios de pacientes con fibrilación auricular, ictus e infarto de miocardio se observaron resultados más modestos. Conclusión Los inhibidores del Factor XI abren nuevas perspectivas en el tratamiento y la profilaxis antitrombótica. Los estudios fase 3 en curso permitirán definir los fármacos e indicaciones más idóneas. (AU)

Background and objective Data from phase 2 clinical trials suggest that factor XI inhibitors may exhibit a more favourable efficacy/safety profile than current antithrombotic therapies. This systematic review aims to analyze the available evidence derived from these studies. Methods A literature search in the PubMed, Cochrane Library, Scopus, EMBASE databases, and clinical trial registration platforms Clinical Trials and Cochrane Central Register of Controlled was conducted. The results were reported in accordance with the PRISMA statement. Results A total of 18 completed or ongoing clinical trials addressing multiple scenarios, including atrial fibrillation, stroke, myocardial infarction, and venous thromboembolism, were identified. Evidence from 8 studies with available results was analyzed. Overall, phase 2 studies with factor XI inhibitors demonstrated an acceptable efficacy and safety profile. The benefit-risk balance, in terms of reducing venous thromboembolism in patients undergoing total knee arthroplasty, was more favourable. For this scenario, factor XI inhibitors showed a 50% reduction in the overall rate of thrombotic complications and a 60% reduction in bleeding compared to enoxaparin. Modest results in studies involving patients with atrial fibrillation, stroke, and myocardial infarction were observed. Conclusions Factor XI inhibitors offer new prospects in antithrombotic treatment and prevention. Ongoing phase 3 studies will help define the most suitable drugs and indications. (AU)

Late device-related thrombus associated with occult malignancy years after left atrial appendage closure.

INTRODUCTION: The use of Left Atrial Appendage (LAA) occluder devices has been on the rise in patients with atrial fibrillation. Studies regarding the long-term risks of occluder devices remain sparse. MATERIALS & METHODS: In this brief report, we discuss the unusual case of an 85-year-old female with long-term complication from Left Atrial Appendage (LAA) closure: Device-Related Thrombus (DRT) about two years after insertion. RESULTS: Compared to the expected stroke rate without anticoagulation, patients with DRT on their LAAO device still had a 28 % relative reduction in ischemic stroke. This suggests that these strokes may have emanated from alternate etiologies other than the DRT. CONCLUSIONS: Patients with active or known history of cancer appears to have a higher risk of DRT. More data is needed on this topic to augment awareness and understanding of LAAO complications and DRT management strategies.

Clinical Outcomes and Predictors of Advanced Therapy for the Management of Right Heart Thrombus.

BACKGROUND: The role of advanced therapies (systemic thrombolysis, catheter-based treatment, and surgical thrombectomy) for the management of right heart thrombus is poorly defined. In this study, we assessed the clinical predictors and outcomes of advanced therapy compared with anticoagulation alone for the acute management of right heart thrombus. METHODS: In this observational cohort study, we analyzed consecutive patients who were treated for right heart thrombus. The primary end point was 90-day all-cause mortality. Clinical predictors of utilizing advanced therapy were assessed with multivariable logistic regression. Propensity score matching was utilized to compare adjusted outcomes between patients receiving advanced therapies versus anticoagulation alone. RESULTS: A total of 345 patients were included in the study. Advanced therapy was utilized in 13.6% (N=47) of patients, of which 25.5% (N=12/47) was systemic thrombolysis, 23.4% (N=11/47) was endovascular thrombectomy, and 53.2% (N=25/47) was surgical thrombectomy. Younger age (odds ratio, 0.98 [95% CI, 0.96-0.99]) and concurrent pulmonary embolism (odds ratio, 5.36 [95% CI, 2.48-12.1]) predicted utilization of advanced therapy. In propensity score-matched analysis, there was no difference in 90-day mortality (hazard ratio, 0.46 [95% CI, 0.17-1.22]), in-hospital mortality (odds ratio, 0.64 [95% CI, 0.17-2.19]), or length of stay (ß, -4.39 [95% CI, -14.0 to 5.22]) between advanced therapy and anticoagulation. CONCLUSIONS: Among a diverse cohort of patients with right heart thrombus, outcomes did not differ between those who underwent advanced therapy and anticoagulation alone. Important predictors for utilizing advanced treatment included younger age and the presence of a concurrent pulmonary embolism. Future studies assessing advanced therapy in larger and broader patient populations are necessary.

Nanoparticles for Thrombus Diagnosis and Therapy: Emerging Trends in Thrombus-theranostics.

Cardiovascular disease is one of the chief factors that cause ischemic stroke, myocardial infarction, and venous thromboembolism. The elements that speed up thrombosis include nutritional consumption, physical activity, and oxidative stress. Even though the precise etiology and pathophysiology remain difficult topics that primarily rely on traditional medicine. The diagnosis and management of thrombosis are being developed using discrete non-invasive and non-surgical approaches. One of the emerging promising approach is ultrasound and photoacoustic imaging. The advancement of nanomedicines offers concentrated therapy and diagnosis, imparting efficacy and fewer side effects which is more significant than conventional medicine. This study addresses the potential of nanomedicines as theranostic agents for the treatment of thrombosis. In this article, we describe the factors that lead to thrombosis and its consequences, as well as summarize the findings of studies on thrombus formation in preclinical and clinical models and also provide insights on nanoparticles for thrombus imaging and therapy.

Magnetically powered microwheel thrombolysis of occlusive thrombi in zebrafish.

Tissue plasminogen activator (tPA) is the only FDA-approved treatment for ischemic stroke but carries significant risks, including major hemorrhage. Additional options are needed, especially in small vessel thrombi which account for ~25% of ischemic strokes. We have previously shown that tPA-functionalized colloidal microparticles can be assembled into microwheels (µwheels) and manipulated under the control of applied magnetic fields to enable rapid thrombolysis of fibrin gels in microfluidic models of thrombosis. Transparent zebrafish larvae have a highly conserved coagulation cascade that enables studies of hemostasis and thrombosis in the context of intact vasculature, clotting factors, and blood cells. Here, we show that tPA-functionalized µwheels can perform rapid and targeted recanalization in vivo. This effect requires both tPA and µwheels, as minimal to no recanalization is achieved with tPA alone, µwheels alone, or tPA-functionalized microparticles in the absence of a magnetic field. We evaluated tPA-functionalized µwheels in CRISPR-generated plasminogen (plg) heterozygous and homozygous mutants and confirmed that tPA-functionalized µwheels are dose-dependent on plasminogen for lysis. We have found that magnetically powered µwheels as a targeted tPA delivery system are dramatically more efficient at plasmin-mediated thrombolysis than systemic delivery in vivo. Further development of this system in fish and mammalian models could enable a less invasive strategy for alleviating ischemia that is safer than directed thrombectomy or systemic infusion of tPA.

Comparison of pharmacological thrombolysis with mechanical thrombectomy in thrombosed arteriovenous fistulas and grafts: a systemic review and meta-analysis.

AIM: To compare the effectiveness and safety of pharmacological thrombolysis and mechanical thrombectomy. MATERIAL AND METHODS: This review was conducted in accordance with the PRISMA guidelines. Pooled proportions and subgroup analysis were calculated for primary and secondary patency rates, technical success, clinical success, major and minor complications rates. RESULTS: This systematic review identified a total of 6,492 studies of which 17 studies were included for analysis. A total of 1,089 patients comprising 451 (41.4 %) and 638 (58.6 %) patients who underwent thrombolysis and mechanical thrombectomy procedures, respectively, were analysed. No significant differences were observed between thrombolysis and mechanical thrombectomy procedures in terms of technical success, clinical success, major and minor complications rates, primary and secondary patency rates; however, subgroup analysis of overall arteriovenous fistulas (AVFs) and arteriovenous grafts (AVGs) demonstrated a significantly higher rate of major complications within the AVF group (p=0.0248). CONCLUSION: The present meta-analysis suggests that pharmacological thrombolysis and mechanical thrombectomy procedures are similarly effective and safe; however, AVFs are subject to higher major complications compared to AVGs.

Combination endovascular and microsurgical treatment of partially thrombosed ruptured ICA terminus aneurysm, with common carotid artery to MCA bypass via saphenous vein graft and parent vessel sacrifice after coil embolization.

A 63-year-old woman presented with ruptured giant ICA terminus aneurysm, temporized with coil embolization and definitively treated with parent vessel sacrifice and high-flow bypass.

Percutaneous treatment of mechanical mitral valve thrombosis.

A 75-year-old female was found to have mechanical mitral valve thrombosis complicated by severe mitral stenosis, pulmonary edema, and right heart failure. She was at prohibitive risk for surgical intervention. She did not tolerate thrombolysis due to bleeding. We performed percutaneous intervention with cerebral protection with subsequent restoration of mechanical mitral valve function, resolution of the mitral valve stenosis, and no neurologic complications.

Plasma Fibrinogen Change as a Predictor of Major Bleeding During Catheter-Directed Thrombolysis.

BACKGROUND: Our primary objective was to determine the relationship between plasma fibrinogen levels (PFLs) and major bleeding complications during catheter-directed thrombolysis, including final, nadir, and change over time. Furthermore, we sought to evaluate additional predictors of bleeding outcomes, including duration of lysis and total dose of tissue plasminogen activator received. METHODS: In this multicenter retrospective cohort study, we reviewed all patients undergoing catheter-directed thrombolysis between January 2016 and August 2021. Patients undergoing thrombolysis for management of peripheral arterial or venous thromboses, as well as for submassive pulmonary embolism, were included. We examined the relationships between PFLs during catheter-directed lysis and the incidence of major bleeding-that is significant hemorrhage requiring transfusion, intracranial hemorrhage, or hemorrhage requiring adjunctive procedures. We also examined the duration of lysis and total lytic agent dose received to assess for association with major bleeding. RESULTS: A total of 438 patients underwent catheter-directed lysis from January 1, 2016 through August 21, 2021, with a major bleeding rate of 16%. Patients who experienced major bleeding were more likely to be older (P = 0.022), experience in-stent thrombosis (P = 0.041), or have thrombosis in a lower extremity vessel (P = 0.011). There was no association between the incidence of major bleeding and a nadir PFL of <150 mg/dL (P = 0.194). Those who experienced major bleeding complications had a significantly greater decrease in PFL from baseline to nadir. This was true for both absolute (P = 0.029) and relative (P = 0.034) PFL decrease. Only percent decrease remained a significant predictor when adjusting for age, thrombosis type, and thrombosis location (P = 0.041). The PFL changes that were the best predictors of major bleeding complications were an absolute decrease of 146 mg/dL, or a relative decrease of 47%, giving a sensitivity and specificity of 71% and 48%, respectively. If neither were true, the negative predictive value for major bleeding was 89% regardless of absolute PFL. CONCLUSIONS: In this large, multicenter cohort, there does not appear to be an association between absolute PFL and major bleeding during catheter-directed lysis. Specifically, the typical absolute threshold of < 150 mg/dL was not an independent predictor of major bleeding. There was an association between percent-change in plasma fibrinogen and major bleeding, which aligns with the underlying physiologic mechanism of fibrinogen degradation coagulopathy. Applying a so-called "50-150 Rule" to catheter-directed lysis may decrease bleeding complications. That is, continued lysis should be re-evaluated if PFL drops by ≥150 mg/dL or by ≥50% from baseline regardless of absolute PFL.

Ultrasound Combined With Continuous Microbubble Injection to Enhance Catheter-Directed Thrombolysis in Vitro and in Vivo.

OBJECTIVES: To investigate the influence of microbubble perfusion mode on catheter-directed thrombolysis (CDT), we evaluated the effect of two different types of microbubble perfusion modes (continuous injection versus bolus injection) on the thrombolytic efficacy of CDT in vitro and further assessed the effect of continuous microbubble injection on CDT in vivo. METHODS: In an in vitro experimental setup, 50 fresh bovine whole blood clots were randomized into five groups: ultrasound and continuous microbubble injection-enhanced CDT (US + cMB + CDT), ultrasound and bolus microbubble injection-enhanced CDT (US + bMB + CDT), US + CDT, US + cMB, and CDT. In a porcine femoral vein thrombosis model, 16 completely obstructive thrombi were randomly assigned to the CDT group and the US + cMB + CDT group, respectively. Thrombolysis rate, vascular recanalization rate, hematoxylin-eosin, and immunofluorescence staining were used to evaluate the thrombolytic effect in vitro and in vivo. RESULTS: In vitro, US + cMB + CDT group resulted in a significantly higher thrombolysis rate compared with the other four groups (P < .05). Meanwhile, this group also demonstrated a looser clot structure and more disrupted fibrin structures. In vivo, US + cMB + CDT contributed to a significantly higher vascular recanalization rate compared with CDT (87.50% versus 25.00%, P < .05). CONCLUSIONS: US + cMB + CDT was more effective than US + bMB + CDT in thrombolysis, and ultrasound combined with continuous microbubble injection could enhance the thrombolytic efficacy of CDT.

How to diagnose and manage antiphospholipid syndrome.

Antiphospholipid antibodies (aPL) are autoimmune antibodies directed toward phospholipids or phospholipid-protein complexes, particularly those containing ß2-glycoprotein I (ß2GPI). Persistently positive aPL accompanied by arterial or venous thrombosis, or recurrent pregnancy loss, constitutes the antiphospholipid syndrome (APS). Several types of aPL with different specificities have been defined and may be detected in the clinical lab, including lupus anticoagulants (detected using clotting assays) and anticardiolipin, anti-ß2GPI and anti-prothrombin/phosphatidylserine antibodies (detected by ELISA); each of the last 3 aPL may be either IgG, IgM, or IgA, though IgA antibodies are not included in criteria for APS. Due to the relative rarity of APS and the heterogeneity of aPL, thrombosis risk stratification is challenging, and randomized clinical trials for thrombosis treatment and prevention have been limited. This lack of high-quality data has made the clinical management of APS difficult, and existing guidelines are few and could not possibly cover many of the scenarios encountered in managing patients with APS. In this review, we present 3 patients with aPL and/or APS who highlight treatment dilemmas, and we discuss background information that may help guide clinical judgment in developing individualized treatment plans for patients with these enigmatic antibodies.