Edoxaban for 12 Months Versus 3 Months in Patients With Cancer With Isolated Distal Deep Vein Thrombosis (ONCO DVT Study): An Open-Label, Multicenter, Randomized Clinical Trial.

BACKGROUND: The optimal duration of anticoagulation therapy for isolated distal deep vein thrombosis in patients with cancer is clinically relevant, but the evidence is lacking. The prolonged anticoagulation therapy could have a potential benefit for prevention of thrombotic events; however, it could also increase the risk of bleeding. METHODS: In a multicenter, open-label, adjudicator-blinded, randomized clinical trial at 60 institutions in Japan, we randomly assigned patients with cancer with isolated distal deep vein thrombosis, in a 1-to-1 ratio, to receive either a 12-month or 3-month edoxaban treatment. The primary end point was a composite of a symptomatic recurrent venous thromboembolism (VTE) or VTE-related death at 12 months. The major secondary end point was major bleeding at 12 months, according to the criteria of the International Society on Thrombosis and Haemostasis. The primary hypothesis was that a 12-month edoxaban treatment was superior to a 3-month edoxaban treatment with respect to the primary end point. RESULTS: From April 2019 through June 2022, 604 patients were randomized, and after excluding 3 patients who withdrew consent, 601 patients were included in the intention-to-treat population: 296 patients in the 12-month edoxaban group and 305 patients in the 3-month edoxaban group. The mean age was 70.8 years, 28% of the patients were men, and 20% of the patients had symptoms of deep vein thrombosis at baseline. The primary end point of a symptomatic recurrent VTE event or VTE-related death occurred in 3 of the 296 patients (1.0%) in the 12-month edoxaban group and in 22 of the 305 patients (7.2%) in the 3-month edoxaban group (odds ratio, 0.13; 95% CI, 0.03-0.44). The major secondary end point of major bleeding occurred in 28 of the 296 patients (9.5%) in the 12-month edoxaban group and in 22 of the 305 patients (7.2%) in the 3-month edoxaban group (odds ratio, 1.34; 95% CI, 0.75-2.41). The prespecified subgroups did not affect the estimates on the primary end point. CONCLUSIONS: In patients with cancer with isolated distal deep vein thrombosis, 12 months was superior to 3 months for an edoxaban treatment with respect to the composite outcome of a symptomatic recurrent VTE or VTE-related death. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03895502.

Statins use and recurrent venous thromboembolism in the direct oral anticoagulant era: insight from the COMMAND VTE Registry-2.

Statins were reported to have a potential effect of primary prevention of venous thromboembolism (VTE), although that of secondary prevention remains uncertain. To investigate the association between statins use and recurrent VTE in the current era. The COMMAND VTE Registry-2 is a multicenter registry enrolling 5,197 consecutive VTE patients among 31 centers in Japan between January 2015 and August 2020. We divided the entire cohort into 2 groups according to statins use at the time of discharge; the statins (N = 865) and no statins groups (N = 4332). The statins group was older (72.9 vs. 66.7 years, P < 0.001), and less often had active cancer (22.0% vs. 30.4%, P < 0.001). The cumulative incidence of discontinuation of anticoagulation was significantly lower in the statins group (60.3% vs. 52.6%, Log-rank P < 0.001). The cumulative 5-year incidence of recurrent VTE was significantly lower in the statins group (6.8% vs. 10.1%, Log-rank P = 0.01). Even after adjusting for the confounders, the lower risk of the statins group relative to the no statins group remained significant for recurrent VTE (HR 0.65, 95% CI 0.45-0.91, P = 0.01). The cumulative 5-year incidence of major bleeding was significantly lower in the statins group (12.2% vs. 14.1%, Log-rank P = 0.04), although, after adjusting for the confounders, the risk of the statins group relative to the no statins group turned to be insignificant (HR 0.77, 95% CI 0.59-1.00, P = 0.054). In this large real-world VTE registry, statins use was significantly associated with a lower risk for the recurrent VTE in the current era.

Association Between the Development of Thrombosis and Worsening of Disease Severity in Patients With Moderate COVID-19 on Admission　- From the CLOT-COVID Study.

BACKGROUND: The worsening of coronavirus disease 2019 (COVID-19) severity is a critical issue in current clinical settings and may be associated with the development of thrombosis.Methods and Results: This study used patient data obtained in the CLOT-COVID study, a retrospective multicenter cohort study. The demographics of patients with moderate COVID-19 on admission with and without worsened severity during hospitalization were compared and predictors were identified. Of 927 patients with moderate COVID-19 on admission, 182 (19.6%) had worsened severity during hospitalization. Patients with worsening of severity were older, more likely to have hypertension, diabetes, heart disease, and active cancer, and more likely to use pharmacological thromboprophylaxis. Patients with worsening of severity had higher D-dimer levels on admission and were more likely to develop thrombosis and major bleeding during hospitalization than those without worsening. Increased age (odds ratio [OR]: 1.02, 95% confidence interval [CI]: 1.01-1.03, P=0.005), diabetes (OR: 1.63, 95% CI: 1.11-2.33, P=0.012), D-dimer levels >1.0 µg/mL on admission (OR: 2.10, 95% CI: 1.45-3.03, P<0.001), and thrombosis (OR: 6.28, 95% CI: 2.72-14.53, P<0.001) were independently associated with worsening of COVID-19 severity. CONCLUSIONS: Approximately 20% of patients with moderate COVID-19 had worsened severity during hospitalization. Increased age, diabetes, D-dimer levels >1.0 µg/mL on admission, and the development of thrombosis during hospitalization were significantly associated with worsened COVID-19 severity.

Mortality-associated Risk Factors in Hospitalized COVID-19 Patients in Japan: Findings of the CLOT-COVID Study.

BACKGROUND: Reports of mortality-associated risk factors in patients with the novel coronavirus disease 2019 (COVID-19) are limited. METHODS: We evaluated the clinical features that were associated with mortality among patients who died during hospitalization (n = 158) and those who were alive at discharge (n = 2,736) from the large-scale, multicenter, retrospective, observational cohort CLOT-COVID study, which enrolled consecutively hospitalized COVID-19 patients from 16 centers in Japan from April to September 2021. Data from 2,894 hospitalized COVID-19 participants of the CLOT-COVID study were analyzed in this study. RESULTS: Patients who died were older (71.1 years vs 51.6 years, P < 0.001), had higher median D-dimer values on admission (1.7 µg/mL vs 0.8 µg/mL, P < 0.001), and had more comorbidities. On admission, the patients who died had more severe COVID-19 than did those who survived (mild: 16% vs 63%, moderate: 47% vs 31%, and severe: 37% vs 6.2%, P < 0.001). In patients who died, the incidence of thrombosis and major bleeding during hospitalization was significantly higher than that in those who survived (thrombosis: 8.2% vs 1.5%, P < 0.001; major bleeding: 12.7% vs 1.4%, P < 0.001). Multivariable logistic regression analysis revealed that age >70 years, high D-dimer values on admission, heart disease, active cancer, higher COVID-19 severity on admission, and development of major bleeding during hospitalization were independently associated with a higher mortality risk. CONCLUSION: This large-scale observational study in Japan identified several independent risk factors for mortality in hospitalized patients with COVID-19 that could facilitate appropriate risk stratification of patients with COVID-19.

Therapeutic-Dose vs. Prophylactic-Dose Anticoagulation Therapy for Critically Ill Patients With COVID-19 in a Practice-Based Observational Study.

BACKGROUND: The potential benefit of therapeutic-dose anticoagulation for critically ill patients with coronavirus disease 2019 (COVID-19) is still controversial.Methods and Results: In the CLOT-COVID study, 225 patients with severe COVID-19 on admission requiring mechanical ventilation or extracorporeal membrane oxygenation were divided into patients with therapeutic-dose anticoagulation (N=110) and those with prophylactic-dose anticoagulation (N=115). There was no significant difference in the incidence of thrombosis between the groups (9.1% vs. 7.8%, P=0.73). CONCLUSIONS: Among a cohort of critically ill patients with COVID-19, approximately half received therapeutic-dose anticoagulation, although it did not show a potential benefit compared with prophylactic-dose anticoagulation.

Incidence, risk factors, and clinical impact of major bleeding in hospitalized patients with COVID-19: a sub-analysis of the CLOT-COVID Study.

BACKGROUND: The coronavirus disease 2019 (COVID-19) causes extensive coagulopathy and a potential benefit of anticoagulation therapy has been documented for prevention of thromboembolic events. Bleeding events has also been reported as a notable complication; whereas, the incidence, risks, and clinical impact of bleeding remain unclear. METHOD: The CLOT-COVID Study was a nationwide, retrospective, multicenter cohort study on consecutive hospitalized patients with COVID-19 in Japan between April 2021 and September 2021. In this sub-analysis, we compared the characteristics of patients with and without major bleeding; moreover, we examined the risk factors for and clinical impact of bleeding events. RESULTS: Among 2882 patients with COVID-19, 57 (2.0%) had major bleeding. The incidence of major bleeding increased with COVID-19 severity as follows: 0.5%, 2.3%, and 12.3% in patients with mild, moderate, and severe COVID-19, respectively. COVID-19 severity, history of major bleeding, and anticoagulant type/dose were independently and additively associated with the bleeding incidence. Compared with patients without major bleeding, those with major bleeding exhibited a longer duration of hospitalization (9 [6-14] vs 28 [19-43] days, P < 0.001) and higher mortality during hospitalization (4.9% vs. 35.1%, P < 0.001). CONCLUSIONS: In the real-world clinical practice, the incidence of major bleeding was not uncommon, especially in patients with severe COVID-19. Independent risk factors for major bleeding included history of major bleeding, COVID-19 severity, and anticoagulant use, which could be associated with poor clinical outcomes including higher mortality. Precise recognition of the risks for bleeding may be helpful for an optimal use of anticoagulants and for better outcomes in patients with COVID-19.

Gadolinium contrast balloon pulmonary angioplasty for a patient with chronic thromboembolic pulmonary hypertension and severe iodine allergy.

Chronic thromboembolic pulmonary hypertension (CTEPH) is group 4 pulmonary hypertension caused by organized thrombi in the pulmonary arteries. Balloon pulmonary angioplasty (BPA) is an emerging treatment option for patients with inoperable CTEPH but needs contrast media. Therefore, management can be very difficult in patients who have severe iodine allergies. We present a case of a 61-year-old female with CTEPH. Right heart catheterization showed that the mean pulmonary arterial pressure (mPAP) was 47 mmHg. Her organized thrombi were not surgically accessible, so we performed BPA to improve her hemodynamic status. One session of BPA was performed, but the second session was halted because of iodine-induced anaphylactic shock. Despite the administration of pulmonary arterial hypertension-specific drugs for 3 months, the patient's mPAP was still 33 mmHg. CTEPH patients with mPAP ≥30 mmHg have a poor prognosis, so we decided to perform BPA using gadolinium contrast media. A total of six sessions of gadolinium contrast BPA (Gd-BPA) improved the patient's mPAP to the normal range. Gadolinium contrast media could also be used for visualizing pulmonary arteries during BPA. Our report is the first successful case of Gd-BPA, which improved the patient's hemodynamic status to the almost normal range. Gd-BPA may be an attractive treatment option for patients with inoperable CTEPH and severe iodine allergy.

Incidence and Clinical Features of Venous Thromboembolism in Hospitalized Patients With Coronavirus Disease 2019 (COVID-19) in Japan.

BACKGROUND: Coronavirus disease 2019 (COVID-19) reportedly causes venous thromboembolism (VTE), but the status of this complication in Japan was unclear.Methods and Results:The VTE and COVID-19 in Japan Study is a retrospective, multicenter cohort study enrolling hospitalized patients with COVID-19 who were evaluated with contrast-enhanced computed tomography (CT) examination at 22 centers in Japan between March 2020 and October 2020. Among 1,236 patients with COVID-19, 45 (3.6%) were evaluated with contrast-enhanced CT examination. VTE events occurred in 10 patients (22.2%), and the incidence of VTE in mild, moderate, and severe COVID-19 was 0%, 11.8%, and 40.0%, respectively. COVID-19 patients with VTE showed a higher body weight (81.6 vs. 64.0 kg, P=0.005) and body mass index (26.9 vs. 23.2 kg/m2, P=0.04), and a higher proportion had a severe status for COVID-19 compared with those without. There was no significant difference in the proportion of patients alive at discharge between patients with and without VTE (80.0% vs. 88.6%, P=0.48). Among 8 pulmonary embolism (PE) patients, all were low-risk PE. CONCLUSIONS: Among a relatively small number of patients undergoing contrast-enhanced CT examination in Japanese real-world clinical practice, there were no VTE patients among those with mild COVID-19, but the incidence of VTE seemed to be relatively high among severe COVID-19 patients, although all PE events were low-risk without significant effect on mortality risk.

Evolution of patients with chronic thromboembolic pulmonary hypertension treated by balloon pulmonary angioplasty, according to their anticoagulant regimens.

Patients with chronic thromboembolic pulmonary hypertension (CTEPH) need anticoagulant therapy for life. Conventionally, vitamin K antagonists (VKAs) have been used and data about direct oral anticoagulants (DOACs) in CTEPH patients are lacking. Recently, balloon pulmonary angioplasty (BPA) has emerged as a treatment option for CTEPH. However, there are no reports examining the effects of DOACs and VKAs on the hemodynamics of patients after BPA. The aim of this study was to compare DOACs and VKAs regarding the hemodynamic changes in patients with CTEPH treated by BPA. Patients who were treated by BPA and underwent follow-up right heart catheterization 6 ± 1 months after the final BPA procedure were included in this study. The subjects were divided into two groups based on the anticoagulant administered, and hemodynamic changes (mean pulmonary artery pressure, mPAP; pulmonary vascular resistance, PVR; cardiac index, CI) were assessed. Of the 65 consecutive patients, 29 met the inclusion criteria (DOAC-group n = 14, VKA-group n = 15). Compared to pre-BPA, post-BPA hemodynamic parameters were improved in both groups. There was no significant difference between the two groups regarding pre-BPA, post-BPA, 6Mo-f/u and Δhemodynamic parameters (difference between 6Mo-f/u and post-BPA, ΔmPAP, - 0.7 ± 3.3 vs. - 2.7 ± 5.4 mmHg, p = 0.24; ΔPVR, - 41.9 ± 80.9 vs. - 16.4 ± 74.1 dyne s/cm5, p = 0.38; ΔCI, - 0.06 ± 0.35 vs. - 0.10 ± 0.35 L/min/m2, p = 0.80; DOAC-group vs. VKA-group, respectively). Hemodynamic improvement by BPA was maintained over 6 months of follow-up irrespective of the type of anticoagulant administered in CTEPH patients.

The predictors of complications in balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension.

OBJECTIVES: The aims of this study were to (1) evaluate risk factors of complications of balloon pulmonary angioplasty (BPA) and (2) assess the mechanism of the complications. BACKGROUND: BPA represents a promising treatment option in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH). However, the complication ratio differs across reports, and the causes remain controversial. METHODS: All complications found by angiography and non-contrasted computerized tomography (CT) immediately after BPA were recorded. New emergences of a ground-glass pattern or consolidation in CT after BPA that were not recognized on CT images before BPA were counted as pulmonary bleeding. Lesion morphologies were classified into four types (web, ring, abrupt narrowing and occlusive lesions) according to selective pulmonary angiography. RESULTS: Thirty patients consented to analysis of the BPA-related images, and 879 lesions (112 sessions) were evaluated. One hundred and twenty-two (99.2%) of 123 complications were confirmed to be associated with BPA procedures at the local area. In the multivariate analysis, occlusive lesions were the sole independent predictor of procedure-related complications (adjusted odds ratio 5.83, 95%CI [1.94-17.47], p = 0.002). Hemodynamic parameters were not predictors of complications. CT images after BPA presented the predictive value for the occurrence of hemoptysis. CONCLUSIONS: Almost all complications were attributed to operators' procedures. Lesion morphology was the sole predictor of BPA-related complications, while hemodynamic parameters were not associated with the frequency of complications. CT scan images after BPA were useful to identify bleeding complications and to predict hemoptysis.

Point of care assessment of cardiac troponin T level in CKD patients with chest symptom.

We challenged to identify the cutoff value of cTnT in chronic kidney disease (CKD) patients by point of care assessment way. A single center, prospective cross-sectional study was planned and performed. 201 consecutive patients who were visited emergency room for chest symptoms were enrolled in this study. All patients were performed routine practice for differential diagnosis of chest symptom by cardiologist. Simultaneously, semiquantitative measurement of cTnT was performed using same blood sampling on the blind condition to cardiologists for this study. Study patients were divided into four groups according to the estimated glomerular filtration rate (eGFR), CKD1-2, CKD3, CKD4-5, and CKD5D. Usefulness of semiquantitative measurement for diagnosing ACEs was investigated in each group. 77 (38%) of total patient was diagnosed as acute coronary events (ACEs). About 50% of patients were showing cTnT level less than 0.03 ng/mL. The cTnT level over 0.1 ng/mL was found in 30% of total subjects. Mean quantitative value of cTnT was 0.29 ± 0.57 ng/mL in total subjects. Estimated cutoff value in CKD3 patients was 0.088 ng/mL with a sensitivity of 59.3% and specificity of 80.0%. Interestingly, the cutoff values of CKD1-2, CKD4-5, and CKD5D were 0.047, 0.18, and 0.27 respectively, which are half, two times, and three times of CKD3 cutoff value 0.088. The specificities of four cutoff values in each CKD group were showing over 80%, which is higher than sensitivity, respectively. In CKD patients, semiquantitative, point of care assessment of cTnT could be a useful tool for screening for ACEs.

Plaque Tissue Morphology-Based Stroke Risk Stratification Using Carotid Ultrasound: A Polling-Based PCA Learning Paradigm.

Severe atherosclerosis disease in carotid arteries causes stenosis which in turn leads to stroke. Machine learning systems have been previously developed for plaque wall risk assessment using morphology-based characterization. The fundamental assumption in such systems is the extraction of the grayscale features of the plaque region. Even though these systems have the ability to perform risk stratification, they lack the ability to achieve higher performance due their inability to select and retain dominant features. This paper introduces a polling-based principal component analysis (PCA) strategy embedded in the machine learning framework to select and retain dominant features, resulting in superior performance. This leads to more stability and reliability. The automated system uses offline image data along with the ground truth labels to generate the parameters, which are then used to transform the online grayscale features to predict the risk of stroke. A set of sixteen grayscale plaque features is computed. Utilizing the cross-validation protocol (K = 10), and the PCA cutoff of 0.995, the machine learning system is able to achieve an accuracy of 98.55 and 98.83%corresponding to the carotidfar wall and near wall plaques, respectively. The corresponding reliability of the system was 94.56 and 95.63%, respectively. The automated system was validated against the manual risk assessment system and the precision of merit for same cross-validation settings and PCA cutoffs are 98.28 and 93.92%for the far and the near wall, respectively.PCA-embedded morphology-based plaque characterization shows a powerful strategy for risk assessment and can be adapted in clinical settings.

Comparison of intravascular optical frequency domain imaging versus intravascular ultrasound during balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension.

OBJECTIVES: The aims of this study are (1) to evaluate the safety and feasibility of using optical frequency domain imaging (OFDI) during balloon pulmonary angioplasty (BPA) procedures, (2) to assess the correlations between the vessel area (VA) and luminal area (LA) obtained by OFDI and intravascular ultrasound (IVUS), and (3) to compare inter- and intra-observer variability among measurements taken from OFDI and IVUS images. BACKGROUND: The BPA in patients with chronic thromboembolic pulmonary hypertension (CTEPH) is an evolving procedure. METHODS: Twenty-three consecutive attempts of pair of OFDI and IVUS during BPA were evaluated. All complications that occurred during-BPA and up to 48 hr post-BPA were recorded. Using side branches as landmarks, 48 pairs of regions were chosen to compare measurements of VA and LA. RESULTS: OFDI images can be obtained without any procedurally related complications. Although the VA and LA measurements obtained by OFDI were smaller than those obtained by IVUS, high correlations were found (VA: r = 0.78, P < 0.0001 and LA: r = 0.75, P < 0.0001). Less inter- and intra-observer variability was found when using measurements taken from OFDI versus IVUS images. CONCLUSIONS: OFDI during BPA was safe and feasible. The reproducibility of OFDI imaging was excellent and offered a favorable addition to the BPA procedures. © 2016 The Authors Catheterization and Cardiovascular Interventions Published by Wiley Periodicals, Inc.

Relationship between leukoaraiosis, carotid intima-media thickness and intima-media thickness variability: Preliminary results.

OBJECTIVE: To assess the relationship between the degree of leukoaraiosis (LA), carotid intima-media thickness (IMT) and intima-media thickness variability (IMTV). MATERIALS AND METHODS: Sixty-one consecutive patients, who underwent a brain MRI examination and a carotid artery ultrasound, were included in this retrospective study, which conformed with the Declaration of Helsinki. Written informed consent was waived. In each patient, right/left carotid arteries and brain hemispheres were assessed using automated software for IMT, IMTV and LA volume. RESULTS: The mean hemispheric LA volume was 2,224 mm3 (SD 2,702 mm3) and there was no statistically significant difference in LA volume between the right and left hemispheres (p value = 0.628). The mean IMT and IMTV values were 0.866 mm (SD 0.170) and 0.143 mm (SD 0.100), respectively, without significant differences between the right and left sides (p values 0.733 and 0.098, respectively). The correlation coefficient between IMTV and LA volume was 0.41 (p value = 0.0001), and 0.246 (p value = 0.074) between IMT and LA volume. CONCLUSIONS: IMTV significantly correlates with LA volume. Further studies are warranted to verify whether this parameter can be used clinically as a marker of cerebrovascular risk. KEY POINTS: • Intima-media thickness variability (IMTV) significantly correlates with leukoaraiosis volume. • IMTV could be used as a marker for cerebrovascular risk. • IMTV seems to be a better predictor of weighted mean difference than IMT.

Carotid inter-adventitial diameter is more strongly related to plaque score than lumen diameter: An automated tool for stroke analysis.

PURPOSE: To compare the strength of correlation between automatically measured carotid lumen diameter (LD) and interadventitial diameter (IAD) with plaque score (PS). METHODS: Retrospective study on a database of 404 common carotid artery B-mode sonographic images from 202 diabetic patients. LD and IAD were computed automatically using an advanced computerized edge detection method and compared with two distinct manual measurements. PS was computed by adding the maximal thickness in millimeters of plaques in segments taken from the internal carotid artery, bulb, and common carotid artery on both sides. RESULTS: The coefficient of correlation was 0.19 (p < 0.007) between LD and PS, and 0.25 (p < 0.0006) between IAD and PS. After excluding 10 outliers, coefficient of correlation was 0.25 (p < 0.0001) between LD and PS, and 0.38 (p < 0.0001) between IAD and PS. The precision of merit of automated versus the two manual measurements was 96.6% and 97.2% for LD, and 97.7% and 98.1%, for IAD, respectively. CONCLUSIONS: Our automated measurement system gave satisfying results in comparison with manual measurements. Carotid IAD was more strongly correlated to PS than carotid LD in this population sample of Japanese diabetic patients.

Reliable and Accurate Calcium Volume Measurement in Coronary Artery Using Intravascular Ultrasound Videos.

Quantitative assessment of calcified atherosclerotic volume within the coronary artery wall is vital for cardiac interventional procedures. The goal of this study is to automatically measure the calcium volume, given the borders of coronary vessel wall for all the frames of the intravascular ultrasound (IVUS) video. Three soft computing fuzzy classification techniques were adapted namely Fuzzy c-Means (FCM), K-means, and Hidden Markov Random Field (HMRF) for automated segmentation of calcium regions and volume computation. These methods were benchmarked against previously developed threshold-based method. IVUS image data sets (around 30,600 IVUS frames) from 15 patients were collected using 40 MHz IVUS catheter (Atlantis® SR Pro, Boston Scientific®, pullback speed of 0.5 mm/s). Calcium mean volume for FCM, K-means, HMRF and threshold-based method were 37.84 ± 17.38 mm(3), 27.79 ± 10.94 mm(3), 46.44 ± 19.13 mm(3) and 35.92 ± 16.44 mm(3) respectively. Cross-correlation, Jaccard Index and Dice Similarity were highest between FCM and threshold-based method: 0.99, 0.92 ± 0.02 and 0.95 + 0.02 respectively. Student's t-test, z-test and Wilcoxon-test are also performed to demonstrate consistency, reliability and accuracy of the results. Given the vessel wall region, the system reliably and automatically measures the calcium volume in IVUS videos. Further, we validated our system against a trained expert using scoring: K-means showed the best performance with an accuracy of 92.80%. Out procedure and protocol is along the line with method previously published clinically.

Two Automated Techniques for Carotid Lumen Diameter Measurement: Regional versus Boundary Approaches.

The degree of stenosis in the carotid artery can be predicted using automated carotid lumen diameter (LD) measured from B-mode ultrasound images. Systolic velocity-based methods for measurement of LD are subjective. With the advancement of high resolution imaging, image-based methods have started to emerge. However, they require robust image analysis for accurate LD measurement. This paper presents two different algorithms for automated segmentation of the lumen borders in carotid ultrasound images. Both algorithms are modeled as a two stage process. Stage one consists of a global-based model using scale-space framework for the extraction of the region of interest. This stage is common to both algorithms. Stage two is modeled using a local-based strategy that extracts the lumen interfaces. At this stage, the algorithm-1 is modeled as a region-based strategy using a classification framework, whereas the algorithm-2 is modeled as a boundary-based approach that uses the level set framework. Two sets of databases (DB), Japan DB (JDB) (202 patients, 404 images) and Hong Kong DB (HKDB) (50 patients, 300 images) were used in this study. Two trained neuroradiologists performed manual LD tracings. The mean automated LD measured was 6.35 ± 0.95 mm for JDB and 6.20 ± 1.35 mm for HKDB. The precision-of-merit was: 97.4 % and 98.0 % w.r.t to two manual tracings for JDB and 99.7 % and 97.9 % w.r.t to two manual tracings for HKDB. Statistical tests such as ANOVA, Chi-Squared, T-test, and Mann-Whitney test were conducted to show the stability and reliability of the automated techniques.

Shape-based approach for coronary calcium lesion volume measurement on intravascular ultrasound imaging and its association with carotid intima-media thickness.

OBJECTIVES: Coronary calcification plays an important role in diagnostic classification of lesion subsets. According to histopathologic studies, vulnerable atherosclerotic plaque contains calcified deposits, and there can be considerable variation in the extent and degree of calcification. Intravascular ultrasound (IVUS) has demonstrated its role in imaging coronary arteries, thereby displaying calcium lesions. The aim of this work was to develop a fully automated system for detection, area and volume measurement, and characterization of the largest calcium deposits in coronary arteries. Furthermore, we demonstrate the correlation between the coronary calcium IVUS volume and the neurologic risk biomarker B-mode carotid intima-media thickness (IMT). METHODS: Our system automatically detects the frames with calcium, identifies the largest calcium region, and performs shape-based volume measurements. The carotid IMT is measured by using AtheroEdge software (AtheroPoint, LLC) on B-mode ultrasound imaging. RESULTS: Our database consists of low-contrast IVUS videos and corresponding B-mode images from 100 patients. Our experiments showed that the correlation between calcium volumes and carotid IMT was higher for the left carotid artery compared to the right carotid artery (r = 0.066 for the left carotid artery and 0.121 for the right carotid artery). We obtained 97% accuracy for automated calcium detection compared against the scoring given by our expert radiologists. Furthermore, we benchmarked shape-based volume measurement against the conventional method, which used integration of regions and showed a correlation of 84%. CONCLUSIONS: Since carotid IMT is an independent prognostic factor for myocardial infarction, and calcium lesions are correlated with stroke risk, we believe that this automated system for calcium volume measurement could be useful for assessing patients' cardiovascular risk.