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Abstract This study aimed to investigate the relationship between complex aortic plaque (CAP) and short-term as well as long-term outcomes following cardioembolic stroke. CAP is a known risk factor for occurrence and recurrence of ischemic stroke. However, the association of CAP on cardioembolic stroke remains unclear. This was retrospective study using prospective cohort of consecutive patients with cardioembolic stroke who underwent transesophageal echocardiography. The functional outcome was evaluated using the modified Rankin Scale score at 3 months, and long-term outcomes were assessed by recurrence of ischemic stroke and occurrence of major adverse cardiovascular events (MACE). Among 759 patients with cardioembolic stroke, 91 (12.0%) had CAP. Early ischemic stroke recurrence within 3 months was associated with CAP (p = 0.025), whereas CAP was not associated with functional outcome at 3 months (odd ratio 1.01, 95% confidence interval [CI] 0.57–1.84, p = 0.973). During a median follow-up of 3.02 years, CAP was significantly associated with ischemic stroke recurrence (hazard ratio = 2.68, 95% CI 1.48–4.88, p = 0.001) and MACE occurrence (hazard ratio = 1.61, 95% CI 1.03–2.51, p = 0.039). In conclusion, CAP was associated with early ischemic stroke recurrence and poor long-term outcomes in patients with cardioembolic stroke. It might be helpful to consider transesophageal echocardiography for patients with cardioembolic stroke to identify CAP.

Cancer can induce hypercoagulability, which may lead to stroke. This occurs when tumor cells activate platelets as part of their growth and metastasis. Tumor cells activate platelets by generating thrombin and expressing tissue factor, resulting in tumor cell-induced platelet aggregation. Histopathological studies of thrombi obtained during endovascular thrombectomy in patients with acute stroke and active cancer have shown a high proportion of platelets and thrombin. This underscores the crucial roles of platelets and thrombin in cancer-associated thrombosis. Cancer-associated stroke typically occurs in patients with active cancer and is characterized by distinctive features. These features include multiple infarctions across multiple vascular territories, markedly elevated blood D-dimer levels, and metastasis. The presence of cardiac vegetations on echocardiography is a robust indicator of cancer-associated stroke. Suspicion of cancer-associated stroke during endovascular thrombectomy arises when white thrombi are detected, particularly in patients with active cancer. Cancer-associated stroke is almost certain when histopathological examination of thrombi shows a very high platelet and a very low erythrocyte composition. Patients with cancer-associated stroke have high risks of mortality and recurrent stroke. However, limited data are available on the optimal treatment regimen for stroke prevention in these patients. Thrombosis mechanism in cancer is well understood, and distinct therapeutic targets involving thrombin and platelets have been identified. Therefore, direct thrombin inhibitors and/or antiplatelet agents may effectively prevent stroke recurrence. Additionally, this strategy has potential benefits in cancer treatment as accumulating evidence suggests that aspirin use reduces cancer progression, metastasis, and cancer-related mortality. However, clinical trials are necessary to assess the efficacy of this strategy involving the use of direct thrombin inhibitors and/or antiplatelet therapies.

Background: Protease-activated receptor 1 (PAR1) is expressed in human platelets and can be activated by low concentrations of thrombin. Vorapaxar, a selective antagonist of PAR1, inhibits thrombin-induced calcium mobilization in human platelet, which is associated with an increased risk of bleeding. Conversely, the administration of a positive allosteric modulator (PAM) of PAR1 may pose a substantial risk of thrombosis due to inducing excessive platelet activation. In this study, we discovered a novel PAM of PAR1 and investigated the effect of enhanced PAR1 activation by PAM of PAR1 on platelet activation.Methods: To find PAMs of PAR1, a cell-based screen was performed in HT29 cells, and finally, gestodene, an oral contraceptive drug (OC), was identified as a novel PAM of PAR1. The mechanism of action of gestodene and its effects on platelet activation were investigated in human megakaryocytic leukemia cell line MEG-01 cells and human platelet.Results: Gestodene enhanced both thrombin- and PAR1-activating peptide (AP)-induced intracellular calcium levels in a dose-dependent manner without altering PAR2 and PAR4 activity. Gestodene significantly increased PAR1-AP-induced internalization of PAR1 and phosphorylation of ERK1/2, and the enhancing effects were significantly blocked by vorapaxar. Furthermore, gestodene potently increased PAR1-AP induced morphological changes in MEG-01 cells. Remarkably, in human blood, gestodene exerted a robust augmentation of PAR1-AP-induced platelet aggregation, and vorapaxar effectively attenuated the gestodene-induced enhancement of platelet aggregation mediated by PAR1.Conclusion: Gestodene is a selective PAM of PAR1 and suggest one possible mechanism for the increased risk of venous thromboembolism associated with OCs containing gestodene.

Abstract This study aimed to investigate the association between muscle mass deficit and the initial severity of ischemic stroke. The impact of muscle mass deficit on the discharge outcome was also evaluated. This retrospective study included 660 patients with acute ischemic stroke who underwent bioelectrical impedance analyses. We compared the National Institute of Health Stroke Scale (NIHSS) score, occurrence of moderate stroke (NIHSSS ≥ 5) at admission, and unfavorable functional outcome (modified Rankin Scale score ≥ 2) at discharge between patients with and without muscle mass deficit using Poisson and logistic regression analyses. The mean age of the study patients was 65.6 ± 13.0, and 63.3% were males. Muscle mass deficit was present in 24.4% of patients. Muscle mass deficit was significantly and independently associated with NIHSS score or moderate stroke (all p

Abstract Clot perviousness on computerized tomography (CT) is predictive of response to reperfusion therapy. This study aimed to determine the association of clot perviousness with ultrastructural features of clot in stroke patients undergoing endovascular thrombectomy. We quantitatively analyzed the ultrastructural components identified using scanning electron microscopy. The clot components were determined in the inner portions of the clots. Clot perviousness was assessed as thrombus attenuation increase (TAI) using noncontrast CT and CT angiography. We compared the association between the identified ultrastructural components and clot perviousness. The proportion of pores consisted of 3.5% on scanning electron microscopy images. The proportion of porosity in the inner portion was 2.5%. Among the ultrastructural components, polyhedrocytes were most commonly observed. The mean TAI was 9.3 ± 10.0 (median 5.6, interquartile range 1.1–14.3) Hounsfield units. TAI correlated positively with inner porosity (r = 0.422, p = 0.020). Among the ultrastructural clot components, TAI was independently associated with polyhedrocytes (B = − 0.134, SE = 0.051, p = 0.008). Clot perviousness is associated with porosity and the proportion of polyhdrocytes of clots.

Background d‐Dimer level is a marker of hypercoagulability, which is associated with thrombus formation and resolution. We investigated the value of d‐dimer levels in predicting outcomes of acute ischemic stroke in patients who underwent endovascular treatment (EVT). Methods We analyzed data of patients who underwent only EVT from the SECRET (Selection Criteria in Endovascular Thrombectomy and Thrombolytic Therapy) registry. d‐Dimer levels were routinely measured in 10 of 15 participating hospitals. Patients were grouped into tertiles (tertile 1, tertile 2, and tertile 3) according to d‐dimer levels (lowest, moderate, and highest, respectively). We compared serial scores on the National Institutes of Health Stroke Scale at baseline, on day 1 of hospitalization, and at discharge; functional outcome 3 months after EVT; and rate of mortality within 6 months after EVT. Results In the 170 patients, the median d‐dimer level was 477 ng/mL (interquartile range, 249–988 ng/mL). In tertile 3, the National Institutes of Health Stroke Scale score was higher at discharge than on day 1 of hospitalization. Poor outcome 3 months after EVT (modified Rankin Scale score, ≥3) was more common with high d‐dimer levels (26.3% of tertile 1, 57.1% of tertile 2, and 76.4% of tertile 3; P

Clinical benefit can be time-dependent even after first-pass recanalization (FPR) in endovascular treatment of acute stroke. This study aimed to evaluate the association between favorable outcome and FPR under a specific time frame. Patients who underwent mechanical thrombectomy were retrospectively reviewed. Recanalization status was categorized into four groups based on FPR and dichotomized time from groin puncture to recanalization (P-to-R time). Favorable outcomes were compared between groups. A total of 458 patients were included. As the cutoff of P-to-R time for favorable outcome was 30 min, recanalization status was categorized into FPR (+) with a P-to-R time ≤ 30 min (Group 1), FPR (–) with a P-to-R time ≤ 30 min (Group 2), FPR (+) with a P-to-R time > 30 min (Group 3), and FPR (–) with a P-to-R time > 30 min (Group 4). Favorable outcomes in Group 3 (37.5%) were significantly less frequent than those in Group 1 (60.4%, p = 0.029) and Group 2 (59.5%, p = 0.033) but were not significantly different from those in Group 4 (35.7%, p = 0.903). Compared to Group 1, Group 3 (adjusted odds ratio, 0.30 [95% confidence interval, 0.12–0.76]; p = 0.011) and Group 4 (0.25 [0.14–0.48]; p < 0.001) were adversely associated with favorable outcomes. FPR was associated with functional outcome in a time-dependent manner. Even for patients who have achieved FPR, their functional outcome might not be favorable if the P-to-R time is >30 min.

Antithrombotic therapy is a cornerstone of acute ischemic stroke (AIS) management and secondary stroke prevention. Since the first version of the Korean Clinical Practice Guideline (CPG) for stroke was issued in 2009, significant progress has been made in antithrombotic therapy for patients with AIS, including dual antiplatelet therapy in acute minor ischemic stroke or high-risk transient ischemic stroke and early oral anticoagulation in AIS with atrial fibrillation. The evidence is widely accepted by stroke experts and has changed clinical practice. Accordingly, the CPG Committee of the Korean Stroke Society (KSS) decided to update the Korean Stroke CPG for antithrombotic therapy for AIS. The writing members of the CPG committee of the KSS reviewed recent evidence, including clinical trials and relevant literature, and revised recommendations. A total of 35 experts were invited from the KSS to reach a consensus on the revised recommendations. The current guideline update aims to assist healthcare providers in making well-informed decisions and improving the quality of acute stroke care. However, the ultimate treatment decision should be made using a holistic approach, considering the specific medical conditions of individual patients.

We aimed to evaluate the association between preprocedural D-dimer levels and endovascular and clinical outcomes. We retrospectively reviewed patients with acute intracranial large-vessel occlusion who underwent mechanical thrombectomy. Plasma D-dimer levels were measured immediately before the endovascular procedure. Endovascular outcomes included successful recanalization, first-pass recanalization (first-pass effect (FPE) and modified FPE (mFPE)), thrombus fragmentation, and the number of passes of the thrombectomy device. Clinical outcomes were assessed at 3 months using the modified Rankin Scale. A total of 215 patients were included. Preprocedural D-dimer levels were lower in patients with FPE (606.0 ng/mL [interquartile range, 268.0–1062.0]) than in those without (879.0 ng/mL [437.0–2748.0]; p = 0.002). Preprocedural D-dimer level was the only factor affecting FPE (odds ratio, 0.92 [95% confidence interval, 0.85–0.98] per 500 ng/mL; p = 0.022). D-dimer levels did not differ significantly based on successful recanalization and thrombus fragmentation. The number of passes of the thrombectomy device was higher (p = 0.002 for trend) and the puncture-to-recanalization time was longer (p = 0.044 for trend) as the D-dimer levels increased. Patients with favorable outcome had significantly lower D-dimer levels (495.0 ng/mL [290.0–856.0]) than those without (1189.0 ng/mL [526.0–3208.0]; p < 0.001). Preprocedural D-dimer level was an independent factor for favorable outcome (adjusted odds ratio, 0.88 [0.81–0.97] per 500 ng/mL; p = 0.008). In conclusion, higher preprocedural D-dimer levels were significantly associated with poor endovascular and unfavorable functional outcomes.

Background and objectiveInflammation is an important factor in the development of aneurysm, and has been identified as a key characteristic predictive of rupture of intracranial aneurysm (IA). However, the role of inflammatory peripheral blood cell ratios in patients with IA has not been well delineated.MethodsA total of 1,209 patients, including 1,001 with unruptured IA and 208 with ruptured IA, were enrolled in this study. Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), platelet-to-neutrophil ratio (PNR), and platelet-to-white-blood-cell ratio (PWR) were compared between ruptured and unruptured IA.ResultsCompared with the ruptured IA group, the unruptured IA group had higher PNR {median, 65.96 [interquartile range (IQR) 48.95–85.05] vs. 37.78 (IQR, 23.17–54.05); p < 0.001} and PWR [median, 36.89 (IQR 29.38–44.56) vs. 22.39 (IQR, 16.72–29.29); p < 0.001]. In multivariate analysis, PNR and PWR were independently associated with ruptured IA (p = 0.001 and p < 0.001, respectively). Unruptured IA subgroup analyses according to the PHASES scores showed that a higher PHASES score was associated with significantly higher NLR and erythrocyte sedimentation rate (p < 0.001 and p = 0.025) and lower PNR and PWR (p < 0.001 and p = 0.007).ConclusionsWe demonstrated that lower PNR and PWR levels are associated with ruptured IA and a higher PHASES score. Unlike many other inflammatory markers and bioassays, peripheral blood cell ratios are inexpensive and readily available biomarkers that may be useful for risk stratification in patients with cerebral aneurysm. However, a long-term prospective study is needed to clarify this matter.

BackgroundAlthough many electrocardiography wearable devices have been released recently for the detection of atrial fibrillation (AF), there are few studies reporting prospective data for wearable devices compared to the strategy of the existing guidelines in the detection of atrial fibrillation (AF) after cryptogenic stroke. A tiny single-patch monitor is more convenient than a conventional Holter monitor recording device and, therefore, longer duration of monitoring may be acceptable.Methods and DesignThe CANDLE-AF study is a multicenter, prospective, randomized controlled trial. Patients with transient ischemic attack or ischemic stroke without any history of AF will be enrolled. The superiority of the 72-h single-patch monitor to standard strategy and non-inferiority of the 72-h single-patch monitor to an event-recorder-type device will be investigated. Single-patch monitor arm will repeat monitoring at 1, 3, 6, and 12 months, event-recorder-type arm will repeat monitoring twice daily for 12 months. The enrollment goal is a total of 600 patients, and the primary outcome is the detection of AF which continues at least 30 s during study period. The secondary outcome is the rate of changes from antiplatelet to anticoagulant and major adverse cardiac and cerebrovascular events within 1 year.ConclusionsThe results of CANDLE-AF will clarify the role of a single-lead patch ECG for the early detection of AF in patients with acute ischemic stroke. In addition, the secondary outcome will be analyzed to determine whether more sensitive AF detection can affect the prognosis and if further device development is meaningful. (cris.nih.go.kr KCT0005592).

Background The purpose of the RAFAS (Risk and Benefits of Urgent Rhythm Control of Atrial Fibrillation in Patients With Acute Stroke) trial was to explore the risks and benefits of early rhythm control in patients with newly documented atrial fibrillation (AF) during an acute ischemic stroke (IS). Method and Results An open‐label, randomized, multicenter trial design was used. If AF was diagnosed, the patients in the early rhythm control group started rhythm control within 2 months after the occurrence of an IS, unlikely the usual care. The primary end points were recurrent IS within 3 and 12 months. The secondary end points were a composite of all deaths, unplanned hospitalizations from any cause, and adverse arrhythmia events. Patients (n=300) with AF and an acute IS (63.0% men, aged 69.6±8.5 years; 51.2% with paroxysmal AF) were randomized 2:1 to early rhythm control (n=194) or usual care (n=106). A total of 273 patients excluding those lost to follow‐up (n=27) were analyzed. The IS recurrences did not differ between the groups within 3 months of the index stroke (2 [1.1%] versus 4 [4.2%]; hazard ratio [HR], 0.257 [log‐rank P=0.091]) but were significantly lower in the early rhythm control group at 12 months (3 [1.7%] versus 6 [6.3%]; HR, 0.251 [log‐rank P=0.034]). Although the rates of overall mortality, any cause of hospitalizations (25 [14.0%] versus 16 [16.8%]; HR, 0.808 [log‐rank P=0.504]), and arrhythmia‐related adverse events (5 [2.8%] versus 1 [1.1%]; HR, 2.565 [log‐rank P=0.372]) did not differ, the proportion of sustained AF was lower in the early rhythm control group than the usual care group (60 [34.1%] versus 59 [62.8%], P

BackgroundIschemic strokes (ISs) can appear even in non-gender-related CHA2DS2-VA scores 0~1 patients with atrial fibrillation (AF). We explored the determinants associated with IS development among the patients with non-gender-related CHA2DS2-VA score 0~1 AF.Methods and ResultsIn this single-center retrospective registry data for AF catheter ablation (AFCA), we included 1,353 patients with AF (24.7% female, median age 56 years, and paroxysmal AF 72.6%) who had non-gender-related CHA2DS2-VA score 0~1, normal left ventricular (LV) systolic function, and available H2FPEF score. Among those patients, 113 experienced IS despite a non-gender-related CHA2DS2-VA score of 0~1. All included patients underwent AFCA, and we evaluated the associated factors with IS in non-gender-related CHA2DS2-VA score 0~1 AF. Patients with ISs in this study had a lower estimated glomerular filtration rate (eGFR) (p < 0.001) and LV ejection fraction (LVEF; p = 0.017), larger LA diameter (p < 0.001), reduced LA appendage peak velocity (p < 0.001), and a higher baseline H2FPEF score (p = 0.018) relative to those without ISs. Age [odds ratio (OR) 1.11 (1.07–1.17), p < 0.001, Model 1] and H2FPEF score as continuous [OR 1.31 (1.03–1.67), p = 0.028, Model 2] variable were independently associated with ISs by multivariate analysis. Moreover, the eGFR was independently associated with IS at low CHA2DS2-VA scores in both Models 1 and 2. AF recurrence was significantly higher in patients with IS (log-rank p < 0.001) but not in those with high H2FPEF scores (log-rank p = 0.079), respectively.ConclusionsAmong the patients with normal LVEF and non-gender-related CHA2DS2-VA score 0~1 AF, the high H2FPEF score, and increasing age were independently associated with IS development (ClinicalTrials.gov Identifier: NCT02138695).

Background and Purpose: Successful reperfusion therapy is supposed to be comprehensive and validated beyond the grade of recanalization. This study aimed to develop a novel scoring system for defining the successful recanalization after endovascular thrombectomy.Methods: We analyzed the data of consecutive acute stroke patients who were eligible to undergo reperfusion therapy within 24 h of onset and who underwent mechanical thrombectomy using a nationwide multicenter stroke registry. A new score was produced using the predictors which were directly linked to the procedure to evaluate the performance of the thrombectomy procedure.Results: In total, 446 patients in the training population and 222 patients in the validation population were analyzed. From the potential components of the score, four items were selected: Emergency Room-to-puncture time (T), adjuvant devices used (A), procedural intracranial bleeding (B), and post-thrombectomy reperfusion status [Thrombolysis in Cerebral Infarction (TICI)]. Using these items, the TAB-TICI score was developed, which showed good performance in terms of discriminating early neurological aggravation [AUC 0.73, 95% confidence interval (CI) 0.67–0.78, P < 0.01] and favorable outcomes (AUC 0.69, 95% CI 0.64–0.75, P < 0.01) in the training population. The stability of the TAB-TICI score was confirmed by external validation and sensitivity analyses. The TAB-TICI score and its derived grade of successful recanalization were significantly associated with the volume of thrombectomy cases at each site and in each admission year.Conclusion: The TAB-TICI score is a valid and easy-to-use tool to more comprehensively define successful recanalization after endovascular thrombectomy in acute stroke patients with large vessel occlusion.

Introduction: Cardioembolic stroke (CE) has poor outcomes and high recurrence rates. A low ankle-brachial index (ABI

Objective To evaluate whether an occlusion pathomechanism can be accurately determined by common preprocedural findings through a machine learning-based prediction model (ML-PM). Methods A total of 476 patients with acute stroke who underwent endovascular treatment were retrospectively included to derive an ML-PM. For external validation, 152 patients from another tertiary stroke center were additionally included. An ML algorithm was trained to classify an occlusion pathomechanism into embolic or intracranial atherosclerosis. Various common preprocedural findings were entered into the model. Model performance was evaluated based on accuracy and area under the receiver operating characteristic curve (AUC). For practical utility, a decision flowchart was devised from an ML-PM with a few key preprocedural findings. Accuracy of the decision flowchart was validated internally and externally. Results An ML-PM could determine an occlusion pathomechanism with an accuracy of 96.9% (AUC=0.95). In the model, CT angiography-determined occlusion type, atrial fibrillation, hyperdense artery sign, and occlusion location were top-ranked contributors. With these four findings only, an ML-PM had an accuracy of 93.8% (AUC=0.92). With a decision flowchart, an occlusion pathomechanism could be determined with an accuracy of 91.2% for the study cohort and 94.7% for the external validation cohort. The decision flowchart was more accurate than single preprocedural findings for determining an occlusion pathomechanism. Conclusions An ML-PM could accurately determine an occlusion pathomechanism with common preprocedural findings. A decision flowchart consisting of the four most influential findings was clinically applicable and superior to single common preprocedural findings for determining an occlusion pathomechanism. [ABSTRACT FROM AUTHOR]

Background Mechanical thrombectomy (MT) is a primary endovascular modality for acute intracranial large vessel occlusion. However, further treatment, such as rescue stenting, is occasionally necessary for refractory cases. We aimed to investigate the efficacy and safety of rescue stenting in first-line MT failure and to identify the clinical factors affecting its clinical outcome. Methods A multicenter prospective registry was designed for this study. We enrolled consecutive patients who underwent rescue stenting for first-line MT failure. Endovascular details and outcomes, follow-up patency of the stented artery, and clinical outcomes were summarized and compared between the favorable and unfavorable outcome groups. Results A total of 78 patients were included. Intracranial atherosclerotic stenosis was the most common etiology for rescue stenting (97.4%). Seventy-seven patients (98.7%) were successfully recanalized by rescue stenting. A favorable outcome was observed in 66.7% of patients. Symptomatic intracranial hemorrhage and mortality were observed in 5.1% and 4.0% of patients, respectively. The stented artery was patent in 82.1% of patients on follow-up angiography. In a multivariable analysis, a patent stent on follow-up angiography was an independent factor for a favorable outcome (OR 87.6; 95% CI 4.77 to 1608.9; p=0.003). Postprocedural intravenous maintenance of glycoprotein IIb/IIIa inhibitor was significantly associated with the follow-up patency of the stented artery (OR 5.72; 95% CI 1.45 to 22.6; p=0.013). Conclusions In this multicenter prospective registry, rescue stenting for first-line MT failure was effective and safe. For a favorable outcome, follow-up patency of the stented artery was important, which was significantly associated with postprocedural maintenance of glycoprotein IIb/IIIa inhibitors. [ABSTRACT FROM AUTHOR]

Purpose: Neutrophils contribute to thrombosis. However, there is limited information on the temporal course of neutrophil recruitment in thrombosis, the contribution of neutrophils to thrombus growth, and the characteristics of stroke patients with neutrophil-rich thrombi. Materials and Methods: After inducing carotid artery thrombosis in Institute of Cancer Research mice using ferric chloride, aged thrombi were produced by ligating the distal portion of the carotid artery in mice for 0.5, 1, 2, 3, 6, or 24 h. For thrombus analysis in stroke patients, we used registry data and thrombi that were obtained during intra-arterial thrombectomy. Immunohistochemistry was performed to determine thrombus composition. Results: In the thrombi of 70 mice, Ly6G positive cell counts (neutrophils) and histone H3-positive cell counts increased in a time-dependent manner (both p<0.001). Ly6G-positive cell count was strongly correlated with histone H3-positive cell counts (r=0.910, p<0.001), but not with thrombus size (p=0.320). In 75 stroke patients, atrial fibrillation and cardioembolism were more frequent in the higher neutrophil group (32/37, 86.5%) than in the lower neutrophil group (19/38, 50%) (p=0.002). The median erythrocyte fraction was higher [52.0 (interquartile range 39.9−57.8)] in the higher neutrophil group than in the lower neutrophil group [40.3 (interquartile range 23.5−53.2)]. The fraction of neutrophils was positively correlated with that of erythrocytes (R=0.35, p=0.002). Conclusion: Neutrophils were recruited and increased in arterial thrombosis in a time-dependent manner; however, they were not associated with the growth of formed thrombi. Neutrophil fractions in the thrombi of stroke patients appeared to be associated with atrial fibrillation and erythrocyte fraction. [ABSTRACT FROM AUTHOR]

Purpose: Interleukin (IL)-17A has been suggested to play a role in the growth and organization of thrombi. We examined whether IL-17A plays a role in the early stages of thrombosis and whether there are sex differences in the effects of IL-17A. Materials and Methods: We performed a blinded, randomized, placebo-controlled study to compare time to thrombotic occlusion and sex differences therein between mice treated with IL-17A and those treated with saline using a ferric chloride-induced model. We also assessed thrombus histology, blood coagulation, and plasma levels of coagulation factors. Results: Time to occlusion values did not differ between the IL-17A group and the control group (94.6±86.9 sec vs. 121.0±84.4 sec, p=0.238). However, it was significantly shorter in the IL-17A group of female mice (74.6±57.2 sec vs. 130.0±76.2 sec, p=0.032). In rotational thromboelastometry, the IL-17A group exhibited increased maximum clot firmness (71.3±4.5 mm vs. 66.7±4.7 mm, p=0.038) and greater amplitude at 30 min (69.7±5.2 mm vs. 64.5±5.3 mm, p=0.040) than the control group. In Western blotting, the IL-17A group showed higher levels of coagulation factor XIII (2.2±1.5 vs. 1.0±0.9, p=0.008), monocyte chemoattractant protein-1 (1.6±0.6 vs. 1.0±0.4, p=0.023), and tissue factor (1.5±0.6 vs. 1.0±0.5, p=0.003). Conclusion: IL-17A plays a role in the initial st ages of arterial thrombosis in mice. Coagulation factors and monocyte chemoattractant protein-1 may be associated with IL-17A-mediated thrombosis. [ABSTRACT FROM AUTHOR]

Purpose: The ferric chloride (FeCl3)-induced thrombosis model is widely used for thrombosis research. However, it lacks standardization with uncertainty in the exact mechanism of thrombosis. This study aimed to characterize thrombus formation in a mouse model. Materials and Methods: We investigated thrombus formation and stability using various FeCl3 concentrations (10%, 20%, 30%, 40%, and 50%, w/v) in carotid arteries of the Institute of Cancer Research (ICR) and C57BL/6N mice using the FeCl3-induced thrombosis model. We also investigated thrombus histopathology using immunohistochemistry and electron microscopy. Results: Higher FeCl3 concentrations induced dose-dependent, faster, larger, and more stable thrombus formation in both strains of mice. However, the ICR mice showed better dose-responses in thrombus formation and stability compared to the C57BL/6N mice. Thrombi were fibrin- and platelet-rich without significant changes across FeCl3 concentrations. However, the content of red blood cells (RBCs) increased with increasing FeCl3 concentrations (p for trend <0.001) and inversely correlated with time to occlusion (r=-0.65, p<0.001). While platelets and fibrin were evenly distributed over the thrombus, RBCs were predominantly located near the FeCl3 treatment area. Transmission electron microscopy showed that RBCs attached to and were surrounded by aggregates of degranulated platelets, suggesting their potential role in platelet activation. Conclusion: Faster and larger thrombus formation is induced in a dose-dependent manner by a wide range of FeCl3 concentrations, but the stable thrombus formation requires higher FeCl3 concentrations. Mouse strain affects thrombus formation and stability. RBCs and their interaction with platelets play a key role in the acceleration of FeCl3-induced thrombosis. [ABSTRACT FROM AUTHOR]