74 research outputs found
Maximal Cohen-Macaulay tensor products and vanishing of Ext modules
In this paper, we investigate the maximal Cohen-Macaulay property of tensor
products of modules, and then give criteria for projectivity of modules in
terms of vanishing of Ext modules. One of the applications shows that the
Auslander-Reiten conjecture holds for Cohen-Macaulay normal rings.Comment: 8 page
Identifying Suspicious Regions of Covid-19 by Abnormality-Sensitive Activation Mapping
This paper presents a fully-automated method for the identification of
suspicious regions of a coronavirus disease (COVID-19) on chest CT volumes. One
major role of chest CT scanning in COVID-19 diagnoses is identification of an
inflammation particular to the disease. This task is generally performed by
radiologists through an interpretation of the CT volumes, however, because of
the heavy workload, an automatic analysis method using a computer is desired.
Most computer-aided diagnosis studies have addressed only a portion of the
elements necessary for the identification. In this work, we realize the
identification method through a classification task by using a 2.5-dimensional
CNN with three-dimensional attention mechanisms. We visualize the suspicious
regions by applying a backpropagation based on positive gradients to
attention-weighted features. We perform experiments on an in-house dataset and
two public datasets to reveal the generalization ability of the proposed
method. The proposed architecture achieved AUCs of over 0.900 for all the
datasets, and mean sensitivity and specificity . The method can also identify notable lesions pointed out in the
radiology report as suspicious regions.Comment: 10 pages, 3 figure
Propensity score-matched analysis of six-month outcomes of paclitaxel-coated balloons combined with UltraScore balloons versus conventional scoring balloons for femoropopliteal lesions
PURPOSECombination angioplasty with paclitaxel-coated balloons (PCBs) and conventional scoring balloons for femoropopliteal lesions has demonstrated satisfactory results, even for complex lesions. The UltraScore balloon (Becton Dickinson, New Jersey, USA), which has a maximum length of 300 mm, has two longitudinal 0.010-inch stainless steel wires and is a new treatment option for complex femoropopliteal lesions. However, no studies have evaluated the effect of the UltraScore balloon on femoropopliteal lesions. This study aimed to compare the clinical efficacy of angioplasty over a six-month period using UltraScore balloons versus conventional scoring balloons for the treatment of atherosclerotic femoropopliteal lesions with PCBs.METHODSA retrospective single-center observational study enrolled 272 patients who underwent PCB angioplasty combined with an UltraScore balloon (n = 58) or conventional scoring balloon (n = 214) without bailout stenting. Propensity score matching was used to minimize intergroup differences in baseline characteristics, and six-month outcomes were compared between the two groups. The primary endpoint was a technical success (i.e., residual angiographic stenosis of <30% with non-severe dissection). The secondary endpoints were the incidences of periprocedural complications, restenosis, and target lesion revascularization (TLR).RESULTSAfter propensity score matching, 50 matched pairs of patients were selected for analysis. The UltraScore group had a significantly longer vessel length (192.8 ± 94.9 versus 36.6 ± 7.9 mm, P < 0.001), a lower frequency of non-compliant balloon (26.0% versus 56.0%, P = 0.002), and a smaller PCB diameter (5.32 ± 0.65 versus 5.66 ± 0.52 mm, P = 0.002) compared with the scoring group. The primary endpoint of technical success was significantly higher in the UltraScore group than in the scoring group (76.0% versus 56.0%, P = 0.035). There were no significant differences in periprocedural complications (4.0% versus 2.0%, P = 0.562), six-month restenosis (4.0% versus 8.0%, P = 0.339), and TLR (2.0% versus 4.0%, P = 0.500) between both groups. The multivariate logistic regression analysis showed that UltraScore use was independently associated with an increase in technical success (odds ratio: 2.58; 95% confidence interval: 1.05–6.36, P = 0.040).CONCLUSIONThe use of an UltraScore balloon during PCB angioplasty for femoropopliteal lesions significantly improved technical success compared with conventional scoring balloons. UltraScore use was an independent predictor of technical success, indicating its potential advantages in peripheral intervention procedures
TCT-395 Serial Optical Coherence Tomography Evaluation 6-, 12- and 24-month Follow-up after Nobori Biolimus A9-eluting Stent Implantation
Impact of hemodialysis on local vessel healing and thrombus formation after drug-eluting stent implantation
AbstractBackgroundAlthough hemodialysis (HD) is a suggested risk factor for stent thrombosis, its contribution to local vessel healing after drug-eluting stent (DES) implantation is unclear.MethodsA total of 121 patients (152 lesions treated with DES) who underwent 8-month follow-up coronary angiography with optical coherence tomography (OCT) were enrolled, and the findings were compared between patients with and without HD. To match baseline differences, mid-term OCT findings of 42 propensity score-matched lesions (21 non-HD vs. 21 HD) were compared. Effects of HD on the efficacy of antiplatelet therapy were also evaluated by VerifyNow assay (Accumetrics, San Diego, CA, USA).ResultsPatients with HD had a significantly higher rate of thrombus formation than those without (64% vs. 33%, p=0.007), although the baseline parameters and lesion characteristics differed between the groups. Multivariate logistic regression analysis revealed that HD was associated with an increased risk of thrombus formation (odds ratio 5.991, 95% confidence interval: 1.972–18.199, p=0.002). Even after propensity-matching for patient background and balancing of angiographic and OCT variables, the risk of thrombus formation remained significantly higher in HD patients. The P2Y12-reaction unit was significantly increased after HD (Pre HD: 211±75 vs. Post HD: 262±59, p=0.01), but patients without HD showed no increase during the same elapsed time (221±88 vs. 212±96, p=0.19).ConclusionsHD is a potential risk factor for subclinical thrombus attachment after DES therapy. Systemic problems, such as residual platelet reactivity, associated with HD as well as local vessel features in HD patients might contribute to the increased incidence of thrombus attachment and subsequent onset of thrombotic event after DES implantation
Effect of Daily Glucose Fluctuation on Coronary Plaque Vulnerability in Patients Pre-Treated With Lipid-Lowering Therapy A Prospective Observational Study
AbstractObjectivesThis study sought to investigate the effect of daily glucose fluctuation on coronary plaque properties in patients with coronary artery disease (CAD) pre-treated with lipid-lowering therapy.BackgroundThere is growing evidence that glucose fluctuation, as a residual risk apart from dyslipidemia, is an important factor contributing to the development of CAD.MethodsThis prospective study enrolled 70 consecutive CAD patients who were referred for percutaneous coronary intervention and whose low-density lipoprotein cholesterol level was <120 mg/dl under statin treatment or <100 mg/dl without statins. Daily glucose fluctuation was analyzed by measuring the mean amplitude of glycemic excursion (MAGE). The plaque properties in the culprit and nonculprit lesions were assessed by virtual histology intravascular ultrasound, and the volume percentage of necrotic core within the plaque (%NC) and the presence of thin-cap fibroatheroma were evaluated.ResultsIn total, 165 lesions were evaluated in 70 patients (40 diabetic and 30 nondiabetic patients). %NC was well correlated with MAGE (r = 0.490, p <0.001). A linear mixed effect model showed that MAGE had the strongest effect on %NC (coefficient β = 0.080 ± 0.020 [standard error], p < 0.001). The generalized linear mixed effect model revealed that MAGE was the only independent predictor of the presence of thin-cap fibroatheroma (odds ratio: 1.037; 95% confidence interval: 1.010 to 1.065; p = 0.007).ConclusionsDaily glucose fluctuation may have an effect on coronary plaque vulnerability in patients with CAD pre-treated with lipid-lowering therapy. Further investigations should address the rationale for the early detection and control of glucose fluctuation in the era of universal statin use for CAD patients
COMPARISONS OF EARLY PHASE ARTERIAL REACTION AFTER 2ND GENERATION DRUG-ELUTING AND BARE-METAL STENTS IMPLANTATION IN PATIENTS WITH ST-SEGMENT ELEVATION MYOCARDIAL INFARCTION: 2-WEEK OBSERVATIONS OF OPTICAL COHERENCE TOMOGRAPHY EVALUATION
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