Detection Of Thrombus Research Articles

Abstract 4124839: Does Anticoagulation Status Before LAA Thrombus Detection Influence Stroke Risk?

Introduction: Thrombus in the left atrial appendage (LAA) is known to be one of the risk factors for ischemic stroke, and after the detection of LAA thrombus, anticoagulation therapy is usually administered. However, the role of anticoagulation therapy before the detection of LAA thrombus in the prognosis is still unclear. Hypothesis: We assessed the hypothesis that the anticoagulation status at the time of LAA thrombus detection with transesophageal echocardiography (TEE) affects the future incidence of ischemic stroke. Methods: Patients who underwent TEE and were found to have LAA thrombus were included. Patients were divided into two groups based on their anticoagulation status before TEE. To exclude strokes that might occur due to the detected LAA thrombus itself, landmark analysis was performed by excluding patients who had a stroke or died within 30 days after detection of the LAA thrombus. The difference in the 7-year cumulative incidence of ischemic stroke was assessed using the Gray-test. Fine-Gray proportional hazard regression was utilized to assess the impact of anticoagulation status on ischemic stroke. Results: Among 183 patients detected with LAA thrombus, 15 suffered ischemic stroke or death within 30 days of detection, and 168 patients were included in this study. Of these, 58 patients were treated with anticoagulation therapy before the index detection of LAA thrombus (PreAC group). Patients in the PreAC group were older (median 76 years [interquartile range 51-88 years] vs. 74 years [38-89 years], P = 0.032) than those in the non-PreAC group. The rates of CHA2DS2-VASc score ≥ 2 (93% vs. 89%, P = 0.582), male sex (64% vs. 70%, P = 0.488), and history of atrial fibrillation (98% vs. 95%, P = 0.667) were similar between the two groups. The cumulative ischemic stroke rate was higher in the PreAC group than in the non-PreAC group (P = 0.048, Figure). Even after adjusting for CHA2DS2-VASc score, anticoagulation therapy before detection of LAA thrombus was significantly associated with the cumulative incidence of ischemic stroke (P = 0.049). Conclusions: Anticoagulation status before the detection of LAA thrombus is a determinant of a higher incidence of ischemic stroke. The background mechanisms suggesting a tendency toward thrombus generation even when treated with anticoagulation are proposed.

Postprocessing Method for Enhanced Left Ventricular Thrombus Detection in Echocardiography

Background and Objectives: The incidence of left ventricular thrombus has decreased in recent years due to advancements in reperfusion strategies for acute myocardial infarction and the use of medications to reduce ventricular remodeling. However, the accurate detection of thrombus remains crucial. Echocardiography is a primary diagnostic tool for thrombus detection, but in cases where the apex of the left ventricle is not clearly visualized, contrast injection is often required for diagnosis. We developed a postprocessing Left Ventricular Thrombus Detection Method (LVTDM) to enhance image details in the region of interest, enabling diagnosis without additional contrast injection. A purpose of our study is the evaluation of Left Ventricular Thrombus Detection Method. Materials and Methods: We analyzed echocardiography video files from 29 patients with apical wall motion abnormalities using LVTDM to identify the presence or absence of thrombus in the left ventricular apex. The results were verified with diagnoses obtained from the same echocardiography examinations following contrast injection. Our method demonstrated a sensitivity of 100% and a specificity of 83%, with a negative predictive value of 100% for ruling out thrombus. There was a strong correlation in thrombus detection/ruling out between LVTDM and contrast echocardiography. The Left Ventricular Thrombus Detection Method can be integrated into routine echocardiography examinations to effectively rule out thrombus when the apex is not clearly visualized. The implementation of this method has the potential to reduce the need for contrast injection by approximately half for detecting left ventricular thrombus.

Resolution of silent left atrial thrombi and clinical outcomes in patients with atrial fibrillation: insight from the LAT trial

Abstract Background Silent thrombi in the left atrium (LA), which are thrombi that have not yet caused thromboembolism, are occasionally observed in patients undergoing transesophageal echocardiography (TEE) for atrial fibrillation (AF). However, there is limited data regarding the impact of resolving these silent LA thrombi (LAT) on patient outcomes. Methods We conducted a retrospective review of clinical records from 2010 to 2018 at six hospitals, involving 17,436 TEE procedures for patients with AF. Among these, 297 patients (1.7%) were identified with silent LAT. Of these, 169 patients with follow-up TEE or cardiac computed tomography data for assessing the resolution of LAT were included in this study. The study population were categorized into two groups: the successful resolution group, defined as those with complete LAT resolution without any related events (N=130), and the failed resolution group (N=39). The latter included patients with residual LAT at the last follow-up (N=26), individuals with thromboembolic events (N=8), or those who required surgical intervention for LAT (N=5). Results During the median follow-up period of 394 days (interquartile range, 373-421 days) following thrombi detection, ischemic stroke and systemic thromboembolism (IS/SE) were observed in 10 cases, major bleeding in 23 cases, and all-cause death in 8 cases. In comparison to the successful resolution group, the failed resolution group not only exhibited a higher incidence of IS/SE (1.5% in the successful vs. 20.5% in the failed resolution group, Log-rank p < 0.001) but also showed trends toward increased major bleeding (10% vs. 23.1%, p = 0.033) and higher total mortality rates (3.1% vs. 10.3%, p = 0.05). These differences in composite endpoints were also statistically significant (13.9% vs. 35.9%, p = 0.001). Conclusion In patients with silent LATs were identified, non-resolution of these LATs was associated with not only a higher incidence of IS/SE but also increased rates of major bleeding and all-cause mortality. Conversely, patients who experienced LAT resolution exhibited more preferable prognoses. The status of LAT resolution is closely associated with patient outcomes, underscoring the importance of monitoring LAT resolution in stratifying patient prognoses.

Radiomics-based multimodality prediction of left atrial appendage thrombus using coronary computed tomography angiography

Abstract Background Timely detection of thrombus in the left atrial appendage (LAA) may help guide decision-making. However, existing models have challenges in extracting comprehensive image information. It has been shown that radiomics-based prediction models can be used for accurate identification. This study investigates potential radiomic markers and constructs a highly efficient multimodality prediction model for LAA thrombus in patients undergoing coronary computed tomography angiography (CCTA). Methods We retrospectively enrolled patients with nonvalvular atrial fibrillation (NVAF) who underwent CCTA and transesophageal echocardiography (TEE) from May 2015 to May 2020. These patients were classified into thrombus or non-thrombus groups based on TEE findings. The data were balanced by resampling and assigned to training or test sets. Radiomics was conducted on the extracted features, and a random forest algorithm was employed for feature selection and importance ranking. We constructed different multimodality thrombus prediction models and compared their performance using the area under the receiver operating characteristic curve (AUC) and other efficacy parameters. Results Among 670 patients (60.17±10.98 years, 70.1% male), 5.2% (n=35) had LAA thrombi. A total of 1232 radiomics features were extracted, with 25 features selected using a random forest for modeling. Two radiomics features (Ibp_3D_m1_firstorder Skewness and original_shape_Flatness) ranked the highest. The radiomics-based multimodality prediction model achieved an AUC of 0.964 (95% confidence interval [CI]: 0.947-0.982), an accuracy of 0.926 (95% CI: 0.925-0.926), and an F1 score of 0.924, outperforming other traditional prediction models. Decision curve analysis also indicated that this model provided the best net clinical benefit. Conclusions Radiomics facilitates a comprehensive exploration of predictors associated with LAA thrombi. A radiomics-based multimodality prediction model can significantly enhance the efficiency of non-invasively detecting thrombi.Receiver operating characteristic curveDecision curve analysis

Evolution of Left Ventricular Thrombus on Serial Cardiovascular Magnetic Resonance Imaging.

Current management of left ventricular (LV) thrombus relies on limited, non-contemporary, echocardiography-based studies. Data on LV thrombus evolution and the associated embolic risk are scarce. We aimed to describe the evolution of LV thrombus on serial cardiovascular magnetic resonance imaging (CMR) - the current reference standard for the detection of LV thrombus, and identify correlates of no resolution and the embolic risk associated with resolution status. We conducted a retrospective cohort study of 107 consecutive patients with LV thrombus who had 213 serial CMRs at a median of 255 days after the index CMR. Of these, 97.2% were anticoagulated. At 3 months after detection by CMR, 75% (47/63) had no resolution of LV thrombus; at 6 months, 53% (35/66) had no resolution; and at 12 months, 37% (23/63) had no resolution. Correlates of no resolution at 6 months included a history of myocardial infarction, LV aneurysm, ischemic etiology of cardiomyopathy, and larger thrombus volume. Recurrence of LV thrombus was rare at 5.3%. On survival analysis using the landmark analysis method, embolic events often occurred beyond 6 months, more frequently in patients with unresolved LV thrombus. Our findings challenge previous literature by demonstrating a lower rate of resolution of LV thrombus and substantial embolic risk beyond 6 months associated with unresolved LV thrombus on serial CMR. Our findings advocate for extended anticoagulation, particularly in patients with markers associated with no resolution. These findings have important implications for clinical practice and research into managing patients with LV thrombus.

Application of a Deep Learning-Based Contrast-Boosting Algorithm to Low-Dose Computed Tomography Pulmonary Angiography With Reduced Iodine Load.

The aim of this study was to assess the effectiveness of a deep learning-based image contrast-boosting algorithm by enhancing the image quality of low-dose computed tomography pulmonary angiography at reduced iodine load. This study included 179 patients who underwent low-dose computed tomography pulmonary angiography with a reduced iodine load using 64 mL of a 1:1 mixture of contrast medium from January 1 to June 30, 2023. For single-energy computed tomography, the noise index was set at 15.4 to maintain a CTDIvol of <2 mGy at 80 kVp, and for dual-energy computed tomography, fast kV-switching between 80 and 140 kVp was employed with a fixed tube current of 145 mA. Images were reconstructed by 50% adaptive statistical iterative reconstruction (AR50) and a commercially available deep learning image reconstruction (TrueFidelity) package at a high strength level (TFH). In addition, AR50 images were further processed using a deep learning-based contrast-boosting algorithm (AR50-CB). Quantitative and qualitative image qualities and numbers of involved vessels with thrombus at each pulmonary artery level were compared in the 3 image types using the Friedman test and Wilcoxon signed rank test. Five hundred thirty-seven reconstructed image datasets of 179 patients were analyzed. Quantitative image analysis showed AR50-CB (30.8 ± 10.0 and 28.1 ± 9.6, respectively) had significantly higher signal-to-noise ratio and contrast-to-noise ratio values than AR50 (20.2 ± 6.2 and 17.8 ± 6.2, respectively) (P < 0.001) or TFH (28.3 ± 8.3 and 24.9 ± 8.1, respectively) (P < 0.001). Qualitative image analysis showed that contrast enhancement and noise scores of AR50-CB were significantly greater than those of AR50 (P < 0.001) and that AR50-CB enhancement scores were significantly higher than TFH enhancement scores (P < 0.001). The number of subsegmental pulmonary arteries affected by thrombus detected was significantly greater for AR50-CB (30 for AR50, 30 for TFH, and 55 for AR50-CB, P < 0.001). The use of a deep learning-based contrast-boosting algorithm improved image quality in terms of signal-to-noise ratio and contrast-to-noise ratio values and the detection of thrombi in subsegmental pulmonary arteries.

Cardiac CT vs Echocardiography for Intracardiac Thrombus Detection in Ischemic Stroke: A Systematic Review and Meta-Analysis of 43 Studies.

Ischemic stroke, a leading cause of mortality, necessitates understanding its mechanism for effective prevention. Echocardiography, especially transesophageal echocardiography (TEE), is the gold standard for detection of cardiac sources of stroke including left atrial thrombus, although its invasiveness, operator skill dependence, and limited availability in some centers prompt exploration of alternatives, such as cardiac CT (CCT). We conducted a systematic review and meta-analysis assessing the ability of CCT in the detection of intracardiac thrombus compared with echocardiography. We searched 4 databases up through September 8, 2023. Major search terms included a combination of the terms "echocardiograph," "CT," "TEE," "imaging," "stroke," "undetermined," and "cryptogenic." The current systematic literature review of the English language literature was reported in adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guidelines. We assessed risk of bias using the QUADAS-2 tool and used random-effects meta-analysis to calculate different diagnostic metrics. The meta-analysis investigating CCT vs echocardiography for intracardiac thrombus detection yielded a total of 43 studies of 9,552 patients. Risk-of-bias assessment revealed a predominantly low risk of bias in the flow and timing, index test, and patient selection domains and a predominantly unclear risk of bias in the reference standard domain. The analysis revealed an overall sensitivity of 98.38% (95% CI 89.2-99.78) and specificity of 96.0% (95% CI 92.55-97.88). Subgroup analyses demonstrated that delayed-phase, electrocardiogram-gated CCT had the highest sensitivity (100%; 95% CI 0-100) while early-phase, nongated CCT exhibited a sensitivity of 94.31% (95% CI 28.58-99.85). The diagnostic odds ratio was 98.59 (95% CI 44.05-220.69). Heterogeneity was observed, particularly in specificity and diagnostic odds ratio estimates. CCT demonstrates high sensitivity, specificity, and diagnostic odds ratios in detecting intracardiac thrombus compared with traditional echocardiography. Limitations include the lack of randomized controlled studies, and other cardioembolic sources of stroke such as valvular disease, cardiac function, and aortic arch disease were not examined in our analysis. Large-scale studies are warranted to further evaluate CCT as a promising alternative for identifying intracardiac thrombus and other sources of cardioembolic stroke.

COVID-19-Induced Changes in the Fibrin Network of Pulmonary and Renal Microthrombi

Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection often causes coagulation disorders that affect highly vascularized organs, such as the lungs and kidneys. Objective The objective of this study was to report the histopathological findings of variations in the fibrin pattern of pulmonary and renal microthrombi in patients who died from SARS-CoV-2 infection. Methods Minimally invasive autopsies were performed on 40 patients to collect lung (n=40) and kidney (n=16) tissue samples. Histochemical and immunohistochemical staining techniques were used for histopathological analyses. Premortem laboratory data were obtained from the patients' electronic medical records. Results The lung tissue showed a patchy pattern, characterized by areas of both minimal and severe damage. The most significant histopathological finding was the detection of thrombi with fibrin structures organized into discrete star-shaped units, which were more frequently observed in areas with severe lung injury than in those with minimal lung injury (p = 0.012). Star-shaped fibrin structures were also observed in the renal glomerular capillaries. Immunohistochemical staining revealed the presence of platelets and the procoagulant proteins von Willebrand factor (VWF) and Factor VIII within the star-shaped fibrin thrombi. Patients with star-shaped fibrin thrombi had higher levels of the systemic inflammatory indicators C-reactive protein (CRP) and neutrophil-to-lymphocyte ratio (NLR). Conclusion Our observations suggest that the inflammatory microenvironment resulting from SARS-CoV-2 infection may contribute to the formation of star-shaped fibrin units in the pulmonary and renal microthrombi.

Echocardiographic assessment of left atrial appendage morphology and function-an expert proposal by the German Working Group of Cardiovascular Ultrasound.

The left atrial appendage is a blind ending cardiac structure prone to blood stasis due to its morphology. This structure is a preferred region of thrombogenesis in relation to reduced myocardial contractility of the atrial wall. Blood stasis occurs primarily in low flow conditions. One of the tasks of echocardiography is the analysis of morphology and function of the left atrial appendage. The detection of thrombi by echocardiography is difficult and must be carried out thoroughly and carefully to avoid potential complications-especially in the context of rhythm control. The assessment of thromboembolic risk, especially in patients with unknown and presumed atrial fibrillation is a second challenge by characterizing atrial function and flow conditions in the left atrial appendage. Thus, this proposal focuses on the obvious problems of echocardiography when assessing left atrial appendage and the role of this method in planning a potential interventional closure of left atrial appendage.

Left ventricular thrombus routine screening with contrast echocardiography in patients with anterior ST-elevation myocardial infarction: is it worth it?

BackgroundLeft ventricular (LV) thrombus has a higher incidence among patients with anterior ST-elevation myocardial infarction (STEMI) when compared to other types of acute myocardial infarction and is associated with worse prognosis. The management of LV thrombus diagnosis remains challenging. Contrast echocardiography (transthoracic echocardiography, TTE) has shown potential in improving the accuracy for its diagnosis, thereby influencing treatment strategies concerning antithrombotic/anticoagulation therapy. The aim of this study was to assess the effectiveness of contrast TTE as a routine screening method for detecting LV thrombus in the acute phase of anterior STEMI.MethodsA prospective, single center, randomized controlled trial was conducted among patients with anterior STEMI. The study group underwent contrast TTE, while the control group received a conventional approach. Demographical, clinical, and diagnostic data were collected. Thrombus detection rates were compared between groups.ResultsA total of 68 patients were included (32 in the study group and 36 in the control group). No substantial baseline differences were observed between groups. Thrombus detection rate was 25.0% in the study group and 13.9% in the control group, however these results did not reach statistical significance (P = 0.24). The prevalence of anterior/apical aneurysm was higher in the study group (46.9% vs. 22.2%, P = 0.03).ConclusionsConventional TTE may be adequate for diagnosing LV thrombus in the acute phase of anterior STEMI; however, further larger-scale and multicenter studies are necessary to obtain more robust and conclusive results. Ultrasound contrast may play a significant role in the detection of anterior/apical aneurysms, which are known risk factors for the subsequent development of thrombus.Trial registrationNCT06480929 (ClinicalTrials.gov, Retrospectively registered).

Susceptibility weighted imaging for detection of thrombus in acute ischemic stroke: A cross-sectional study.

Susceptibility-weighted imaging (SWI) can help in the diagnosis of thrombus within the vessel in acute ischemic stroke, known as susceptibility vessel sign (SVS), and detection of SVS within the vessel can predict treatment modality and outcome. In this study, the purpose is to correlate the SVS on SWI with different parameters of stroke. This prospective cross-sectional study enrolled consecutive stroke patients with vessel occlusion on magnetic resonance angiography (MRA) over 1 year. The relationship between SVS on SWI with risk factors, territory involved, and length of thrombus was correlated with the National Institutes of Health Stroke Scale (NIHSS). A total of 105patients were enrolled in this study. Sixty-two percent (66 out of 105) of patients showed SVS on SWI with MRA-positive occlusion. A positive correlation was observed between SVS on SWI and the risk factor (p = 0.003, chi-square test), with 86% of patients with heart disease and 47% with hypertension exhibiting SVS. Additionally, a positive correlation was observed between SVS on SWI and territorial occlusion (p = 0.000, chi-square test). A moderate positive correlation was observed between the NIHSS and thrombus length (p = 0.002, Pearson's correlation coefficient), with a Pearson's coefficient of 0.367. SWI can be useful in identifying the location of the thrombus, and NIHSS can determine the thrombus length in acute stroke. A higher incidence of SVS can be associated with risk factors, and it also depends upon the site of occlusion of the vessel.

Simultaneous portal vein thrombosis and splenic vein thrombosis in a COVID-19 patient: A case report and review of literature

BACKGROUND It is well-described that the coronavirus disease 2019 (COVID-19) infection is associated with an increased risk of thrombotic complications. While there have been many cases of pulmonary emboli and deep vein thrombosis in these patients, reports of COVID-19 associated portal vein thrombosis (PVT) have been uncommon. We present a unique case of concomitant PVT and splenic artery thrombosis in a COVID-19 patient. CASE SUMMARY A 77-year-old-male with no history of liver disease presented with three days of left-sided abdominal pain. One week earlier, the patient was diagnosed with mildly symptomatic COVID-19 and was treated with nirmatrelvir/ritonavir. Physical exam revealed mild right and left lower quadrant tenderness, but was otherwise unremarkable. Significant laboratory findings included white blood cell count 12.5 K/μL, total bilirubin 1.6 mg/dL, aminoaspartate transferase 40 U/L, and alanine aminotransferase 61 U/L. Computed tomography of the abdomen and pelvis revealed acute PVT with thrombus extending from the distal portion of the main portal vein into the right and left branches. Also noted was a thrombus within the distal portion of the splenic artery with resulting splenic infarct. Hypercoagulable workup including prothrombin gene analysis, factor V Leiden, cardiolipin antibody, and JAK2 mutation were all negative. Anticoagulation with enoxaparin was initiated, and the patient’s pain improved. He was discharged on apixaban. CONCLUSION It is quite uncommon for PVT to present simultaneously with an arterial thrombotic occlusion, as in the case of our patient. Unusual thrombotic manifestations are classically linked to hypercoagulable states including malignancy and hereditary and autoimmune disorders. Viral infections such as Epstein-Barr virus, cytomegalovirus, viral hepatitis, and COVID-19 have all been found to increase the risk of splanchnic venous occlusions, including PVT. In our patient, prompt abdominal imaging led to early detection of thrombus, early treatment, and an excellent outcome. This case is unique in that it is the second known case within the literature of simultaneous PVT and splenic artery thrombosis in a COVID-19 patient.

Anti – intercellular adhesion molecule-1(ICAM-1) nanoparticles for damaged endothelium to treat venous thromboembolism

Venous thromboembolism (VTE) is a potentially fatal vascular disease that can be successfully managed to reduce the risk of mortality and impairment. Anticoagulation therapy is frequently recommended for the treatment and prevention of venous thromboembolism. Despite breakthroughs in anticoagulant therapy using parenteral anticoagulant medications and vitamin K antagonists, limits in their usage persist, prompting research into alternative anticoagulants such as factor Xa inhibitors. Of the agents under development, edoxaban shows the most promise due to strong data confirming its therapeutic benefit for VTE. Nanoparticle drug delivery systems (NDDS) are designed technologies that employ nanoparticles to convey therapeutic drugs in a targeted and regulated manner. Intraendothelial transport of therapies in VTE is facilitated by the induction of cell adhesion molecule-mediated endocytosis upon interaction of intercellular adhesion molecule 1 (ICAM-1) on endothelium cells by ICAM-1-targeted carriers. The potential application of NDDS as nanoparticles as anticoagulant agents has been emphasized. There is proof of outstanding efficacy in preventing blood coagulation, dissolving blood clots, and improving in vivo detection of thrombus. These nanoplatforms’ growing evaluations, strong action, enhanced biocompatibility, and lack of problems from excessive bleeding are all positive signs of their possible integration in the clinical treatment of blood coagulation diseases in the future. Additionally, by avoiding biological barriers and enhancing a medication’s therapeutic index, NDDSs offer superior drug delivery to targeted treatment or even directly to the injured site as compared to standard anticoagulants. Emerging scientific and clinical data suggests that NDDS may be a safe, efficacious, and attractive treatment option for a variety of cardiovascular disorders, including thromboembolic syndromes. This study presents an updated knowledge of nanocarriers for thrombosis as well as an outline of recent significant breakthroughs in targeted thrombosis therapy.

Thrombus Detection in the Artificial Heart Pump Based on Electrical Impedance Spectroscopy

Thrombus Detection in the Artificial Heart Pump Based on Electrical Impedance Spectroscopy

Validation of CT in comparison to TEE in routine workflow for detection of LAA thrombus in patients under oral anticoagulation presenting for left atrial ablation

Abstract Background Left atrial (LA) thrombus in patients (pts) presenting for LA ablation is an absolute contraindication to ablation. Although thrombi can still form despite the use of oral anticoagulation (OAC) in advance of the procedure. Transesophageal echocardiography (TEE) has been considered the gold standard for LAA thrombus detection. Additional cardiac computer tomography (CT) is often performed in pts with persistent atrial fibrillation (AF) or atrial tachycardia (AT). The aim of the study was in routine workflow 1) to identify the incidence of LAA thrombi in TEE and CT, 2) to search for an association in detecting LAA thrombi in the 2 methods and 3) to find out if the LAA flow velocity/ LA volume influences the thrombus detection. Methods Between 05/2018 and 10/2023 patients with AF/AT under OAC which were scheduled for a LA ablation were included. TEE and CT searching for LAA thrombus were carried out at intervals of up to 7 days. LAA flow velocity measured in the TEE. The LA volume which included LAA and excluded the pulmonary veins were obtained from the CT at the end-systole. Results Patients characteristics: 283 pts were included, mean age of 66y (+9y), 182 male, mean CHA2DS2-VASc score 3 [0-7]. All patients, mostly on NOACs (n=265), were orally anticoagulated. Mean LA volume (LA + LAA) was 158 ml (+45ml), LAA flow velocity was reduced (&amp;lt; 40 cm/s) in 119 pts (42%). In the majority of cases (73%), TEE and CT were performed at the same day or with an interval of 1 day. In 16 pts a LAA thrombus was detected using TEE,42 pts had SEC/Sludge but no solid thrombus. An LAA thrombus in the CT was described in 26 pts (10%), 6% couldn't definitively diagnose thrombi due to contrast recesses/flow phenomena in 16 pts. In 8 out of 34 events (23%) TEE and CT agreed on the diagnosis of a thrombus, in 6 cases during same-day examinations. 18 pts: LAA thrombus on CT, not on TEE (mean interval: 2d). 8 pts: LAA thrombus on TEE, not on CT (mean interval: 1.5d). In 71% (200 out of 283) of cases, CT and TEE agreed in ruling out a thrombus (p=0.358). LAA flow velocity and thrombus verification by TEE showed a significant correlation (p &amp;lt; 0.001). No correlation was found between the presence of a thrombus on CT and LA volume (p= 0.964). Discussion In 12% of the patients, all treated with OAC, a thrombus was described in at least one of the examinations or in both. Only in one out of four pts TEE and CT agreed on the diagnosis of a thrombus. It was notable that both examinations excluded thrombi in 70%. LAA flow velocity and thrombus verification in the TEE are significant correlated. LA volume and thrombus notification in CT are not related. Conclusion Routine diagnosis of LAA thrombus remains challenging, with frequent discrepancies between TEE, the gold standard, and CT. TEE results depend on the examining physician, while CT is limited by flow phenomena and scan timing.

Direct abdominal vein thrombus imaging (DATI): a contrast-free black-blood MR technique for the diagnosis of abdominal vein thrombosis.

To develop and evaluate a direct abdominal vein thrombus imaging (DATI) technique, based on a respiratory navigating SPACE sequence with DANTE black-blood preparation, for diagnosing abdominal vein thrombosis (AVT) without the use of exogenous contrast agents. We prospectively enrolled 10 healthy subjects and 28 suspected AVT patients who underwentDATI scans on 3.0T MRI. Contrast-enhanced CT venography (CTV) was also conducted on the suspected AVT patients for comparison. All images were analyzed by two blinded radiologists who independently evaluated randomized images and gave image quality and diagnostic confidence scores (1-poor, 4-excellent) for DATI and CTV. The accuracy (ACC), sensitivity (SE), specificity (SP), positive predictive value (PPV), and negative predictive value (NPV) of CTV were calculated using CTV as a standard reference. The diagnostic agreement between DATI and CTV as well as the interobserver agreement were conducted using Cohen κ test. The patient study demonstrated that DATI can provide adequate thrombus signal intensity and the contrast between the thrombus to dark venous lumen for the diagnosis of AVT. It offers good to excellent image quality (reader1/reader2: 3.50 ± 0.64/3.42 ± 0.63, κ = 0.872) and diagnostic confidence (reader1/reader2: 3.71 ± 0.53/3.78 ± 0.42, κ = 0.804) for the diagnosis of AVT. Taking CTV as a reference, DATI has high accuracy (96.6%), SE (91.5%), SP (98.0%), PPV (92.3%), and NPV (97.8%). DATI can provide good to excellent image quality, effective venous blood signal suppression, and definitive thrombus detection for the diagnosis of AVT without the use of exogenous contrast agents.

Early thrombus detection in the extracorporeal membrane oxygenation circuit by noninvasive real-time ultrasonic sensors

Thrombus formation in extracorporeal membrane oxygenation (ECMO) remains a major concern as it can lead to fatal outcomes. To the best of our knowledge, there is no standard non-invasive method for quantitatively measuring thrombi. This study’s purpose was to verify thrombus detection in an ECMO circuit using novel, non-invasive ultrasonic sensors in real-time, utilizing the fact that the ultrasonic velocity in a thrombus is known to be higher than that in the blood. Ultrasonic sensors with a customized chamber, an ultrasonic pulse-receiver, and a digital storage oscilloscope (DSO) were used to set up the measuring unit. The customized chamber was connected to an ECMO circuit primed with porcine blood. Thrombi formed from static porcine blood were placed in the circuit and ultrasonic signals were extracted from the oscilloscope at various ECMO flow rates of 1–4 L/min. The ultrasonic signal changes were successfully detected at each flow rate on the DSO. The ultrasonic pulse signal shifted leftward when a thrombus passed between the two ultrasonic sensors and was easily detected on the DSO screen. This novel real-time non-invasive thrombus detection method may enable the early detection of floating thrombi in the ECMO system and early management of ECMO thrombi.

Detection of occult thrombosis in individuals with Fontan circulation by cardiac MRI.

Identifying thrombus formation in Fontan circulation has been highly variable, with reports between 17 and 33%. Initially, thrombus detection was mainly done through echocardiograms. Delayed-enhancement cardiac MRI is emerging as a more effective imaging technique for thrombus identification. This study aims to determine the prevalence of occult cardiac thrombosis in patients undergoing clinically indicated cardiac MRI. A retrospective chart review of children and adults in the Duke University Hospital Fontan registry who underwent delayed-enhancement cardiac MRI. Individuals were excluded if they never received a delayed-enhancement cardiac MRI or had insufficient data. Demographic characteristics, native heart anatomy, cardiac MRI measurements, and thromboembolic events were collected for all patients. In total, 119 unique individuals met inclusion criteria with a total of 171 scans. The median age at Fontan procedure was 3 (interquartile range 1, 4) years. The majority of patients had dominant systemic right ventricle. Cardiac function was relatively unchanged from the first cardiac MRI to the third cardiac MRI. While 36.4% had a thrombotic event by history, only 0.5% (1 patient) had an intracardiac thrombus detected by delayed-enhancement cardiac MRI. Despite previous echocardiographic reports of high prevalence of occult thrombosis in patients with Fontan circulation, we found very low prevalence using delayed-enhancement cardiac MRI. As more individuals are reaching adulthood after requiring early Fontan procedures in childhood, further work is needed to develop thrombus-screening protocols as a part of anticoagulation management.

Ultrashort VIBE-Dixon versus Cine and late gadolinium enhancement MRI sequences for cardiac thrombus detection

PurposeTo determine the diagnostic accuracy of volumetric interpolated breath-hold examination sequences with fat suppression in Dixon technique (VIBE-Dixon) for cardiac thrombus detection. MethodFrom our clinical database, we retrospectively identified consecutive patients between 2014 and 2022 who had definite diagnosis or exclusion of cardiac thrombus confirmed by an independent adjudication committee, serving as the reference standard. All patients received 2D-Cine plus 2D-Late-Gadolinium-Enhancement (Cine + LGE) and VIBE-Dixon sequences. Two blinded readers assessed all images for the presence of cardiac thrombus. The diagnostic accuracy of Cine + LGE and VIBE-Dixon was determined and compared. ResultsAmong 141 MRI studies (116 male, mean age: 61 years) mean image examination time was 28.8 ± 3.1 s for VIBE-Dixon and 23.3 ± 2.5 min for Cine + LGE. Cardiac thrombus was present in 49 patients (prevalence: 35 %). For both readers sensitivity for thrombus detection was significantly higher in VIBE-Dixon compared with Cine + LGE (Reader 1: 96 % vs.73 %, Reader 2: 96 % vs. 78 %, p < 0.01 for both readers), whereas specificity did not differ significantly (Reader 1: 96 % vs. 98 %, Reader 2: 92 % vs. 93 %, p > 0.1). Overall diagnostic accuracy of VIBE-Dixon was higher than for Cine + LGE (95 % vs. 89 %, p = 0.02) and was non-inferior to the reference standard (Delta ≤ 5 % with probability > 95 %). ConclusionsBiplanar VIBE-Dixon sequences, acquired within a few seconds, provided a very high diagnostic accuracy for cardiac thrombus detection. They could be used as stand-alone sequences to rapidly screen for cardiac thrombus in patients not amenable to lengthy acquisition times.

Predictive Maintenance Approach in Ventricular Assist Devices: Safeguarding Against Thrombus Formation

Affecting millions in the world, cardiovascular diseases are a public health problem. Some patients are not eligible for heart transplantation. Thus, a possibility is to receive a circulatory device known as a ventricular assist device (VAD). This kind of device shows some problems, like thrombogenesis. The thrombus formation in a VAD can cause patient death, and a previous, non-invasive diagnostic is quite complex. The objective of this work is to develop an algorithm to reproduce time signals that indicate the presence and absence of a thrombus, use these signals to train an artificial neural network to classify them, and use these algorithms in a predictive algorithm for early thrombus detection. The results show that it was possible to detect the thrombus formation in its early stages, but the noise level interferes with the accuracy of the ANN, especially when signals in the time domain are used.