PubMed Health⌕ Search

Biomedical subjects

Osamu Katoh

Publications and source records attributed to Osamu Katoh.

At least 19 recordsLinked to original sources
PubMed2006

Coronary plaque composition of culprit/target lesions according to the clinical presentation: a virtual histology intravascular ultrasound analysis.

AIMS: To evaluate the plaque composition obtained by virtual histology (VH) IVUS according to the clinical presentation and to compare those data to previously published histopathology data. METHODS AND RESULTS: VH was performed on 95 de novo significant lesions (>75% stenosis) in 85 patients [28 acute coronary syndrome (ACS) patients, 30 lesions; 57 stable angina pectoris (SAP) patients, 65 lesions]. There were a higher prevalence of positive remodelling (47 vs. 22%, P=0.013), thrombus (20 vs. 1.5%, P=0.0037), and echo-lucent area (23.3 vs. 7.7%, P=0.047) in ACS patients. At the minimal lumen site, fibrous plaque area was significantly larger in ACS lesions than in SAP lesions (66.0+/-10.7 vs. 61.4+/-8.9%, P=0.034), whereas necrotic core and dense calcium plaque area were smaller in ACS lesions (Necrotic core: 6.8+/-6.0 vs. 11.0+/-8.3%, P=0.02; Dense calcium: 2.6+/-3.0 vs. 4.9+/-5.8%, P=0.03). No differences in rate of thin cap fibroatheroma, thick fibrotheroma, or for the presence of multiple necrotic core layers were observed between both groups. CONCLUSION: Plaque composition obtained by VH-IVUS shows less necrotic core and more fibrous tissue in ACS compared to SAP lesions, which is in contradiction with previously published histopathologic data.

Calcinosis↗
PubMed2006

Accuracy of in vivo coronary plaque morphology assessment: a validation study of in vivo virtual histology compared with in vitro histopathology.

OBJECTIVES: The goal of the present study was to compare the accuracy of in vivo tissue characterization obtained by intravascular ultrasound (IVUS) radiofrequency (RF) data analysis, known as Virtual Histology (VH), to the in vitro histopathology of coronary atherosclerotic plaques obtained by directional coronary atherectomy. BACKGROUND: Vulnerable plaque leading to acute coronary syndrome (ACS) has been associated with specific plaque composition, and its characterization is an important clinical focus. METHODS: Virtual histology IVUS images were performed before and after a single debulking cut using directional coronary atherectomy. Debulking region of in vivo histology image was predicted by comparing pre- and post-debulking VH images. Analysis of VH images with the corresponding tissue cross section was performed. RESULTS: Fifteen stable angina pectoris (AP) and 15 ACS patients were enrolled. The results of IVUS RF data analysis correlated well with histopathologic examination (predictive accuracy from all patients data: 87.1% for fibrous, 87.1% for fibro-fatty, 88.3% for necrotic core, and 96.5% for dense calcium regions, respectively). In addition, the frequency of necrotic core was significantly higher in the ACS group than in the stable AP group (in vitro histopathology: 22.6% vs. 12.6%, p = 0.02; in vivo virtual histology: 24.5% vs. 10.4%, p = 0.002). CONCLUSIONS: Correlation of in vivo IVUS RF data analysis with histopathology shows a high accuracy. In vivo IVUS RF data analysis is a useful modality for the classification of different types of coronary components, and may play an important role in the detection of vulnerable plaque.

Aged↗
PubMed2006

Diagnostic accuracy of 64-slice computed tomography for detecting angiographically significant coronary artery stenosis in an unselected consecutive patient population: comparison with conventional invasive angiography.

BACKGROUND: Multislice computed tomography (MSCT) is a promising noninvasive method of detecting coronary artery disease (CAD). However, most data have been obtained in selected series of patients. The purpose of the present study was to investigate the accuracy of 64-slice MSCT (64 MSCT) in daily practice, without any patient selection. METHODS AND RESULTS: Using 64-slice MSCT coronary angiography (CTA), 69 consecutive patients, 39 (57%) of whom had previously undergone stent implantation, were evaluated. The mean heart rate during scan was 72 beats/min, scan time 13.6 s and the amount of contrast media 72 mL. The mean time span between invasive coronary angiography (ICAG) and CTA was 6 days. Significant stenosis was defined as a diameter reduction of > 50%. Of 966 segments, 884 (92%) were assessable. Compared with ICAG, the sensitivity of CTA to diagnose significant stenosis was 90%, specificity 94%, positive predictive value (PPV) 89% and negative predictive value (NPV) 95%. With regard to 58 stented lesions, the sensitivity, specificity, PPV and NPV were 93%, 96%, 87% and 98%, respectively. On the patient-based analysis, the sensitivity, specificity, PPV and NPV of CTA to detect CAD were 98%, 86%, 98% and 86%, respectively. Eighty-two (8%) segments were not assessable because of irregular rhythm, calcification or tachycardia. CONCLUSION: Sixty-four-MSCT has a high accuracy for the detection of significant CAD in an unselected patient population and therefore can be considered as a valuable noninvasive technique.

Aged↗
PubMed2006

Stent strut fracture-induced restenosis in a bifurcation lesion treated with the crush stenting technique.

Percutaneous treatment of a bifurcation lesion still shows a significant complication rate, mainly because of restenosis at the ostial site of the side branch vessel. Different techniques, such as V-stenting, culottes-stenting or crush stenting, allow full ostial coverage and may therefore achieve uniform drug distribution within the lesion. The crush technique results in a strong mechanical constraint on the side branch stent. A case of stent strut fracture-induced restenosis in a bifurcation lesion treated with the crush stenting technique is described.

Aged↗
PubMed2006

New concept for CTO recanalization using controlled antegrade and retrograde subintimal tracking: the CART technique.

OBJECTIVES: To demonstrate the safety and feasibility of a new concept for CTO recanalization using a controlled antegrade and retrograde subintimal tracking technique (CART technique). BACKGROUND: A successful percutaneous recanalization of chronic coronary occlusions results in improved survival, as well as enhanced left ventricular function, reduction in angina, and improved exercise tolerance. However, successful recanalization of CTOs is still not optimal, and needs further improvements. METHODS: Ten patients with a CTO underwent the CART procedure. This technique combines the simultaneous use of the antegrade and retrograde approaches. A subintimal dissection is created antegradely and retrogradely, which allows the operator to limit the extension of the subintimal dissection in the CTO portion. A retrograde approach means that the occlusion site is approached in a retrograde fashion through the best collateral channel from any other patent coronary artery. RESULTS: The occlusion site was located in the RCA in 9 patients, and in the LAD in 1 patient. CTO duration varied from 7 to 84 months. Vessel recanalization was achieved in all patients. In all cases, the subintimal dissection was limited to the CTO region. No complications occurred in the collateral channel used for the retrograde approach. There were no in-hospital major adverse cardiac events. CONCLUSIONS: The CART technique is feasible, safe, and has a high success rate.

Aged↗
PubMed2005

First clinical experience of a novel penetration catheter for patients with severe coronary artery stenosis.

The study aimed to evaluate the efficacy of a novel penetration catheter for severe coronary artery disease. Severe coronary artery diseases such as chronic total occlusions or severe calcified stenoses sometimes obstruct the subsequent crossing of balloon catheter after successful wire crossing. A novel penetration over-the-wire catheter has been developed for severe coronary artery disease. The main shaft is a coreless stainless coil that consists of eight stranded stainless wires to cross through a severe stenosis by manual rotation. This device was applied during percutaneous coronary intervention for patients with severe coronary artery disease obstructing the subsequent crossing of balloon or microcatheters after successful wire crossing. Initial results were examined. Fourteen eligible patients were enrolled consecutively. Among those, 10 patients had chronic total occlusion and 7 patients showed severe angiographical calcification. The device was successfully crossed through the lesion and enabled subsequent dilatation in all patients without any complication. This new device enables the crossing of severe coronary artery stenoses and therefore favors further dilatation in this lesion subset.

Aged↗
PubMed2005

A comparison of the defective granulopoiesis in childhood cyclic neutropenia and in severe congenital neutropenia.

BACKGROUND AND OBJECTIVES: Cyclic neutropenia (CyN) in childhood and severe congenital neutropenia (SCN) are congenital disorders that cause chronic neutropenia. Mutations in the neutrophil elastase gene, ELA2, have been reported in patients with CyN and in those with SCN. We examined granulopoietic defects in CyN patients with those in SCN patients. DESIGN AND METHODS: Three patients with CyN and four with SCN were enrolled in this study. Bone marrow cells were enriched based on the expression of CD34, Kit, and granulocyte colony-stimulating factor receptor (G-CSFR). The purified cells were assayed for colony formation, proliferation, and mRNA expression of granular enzymes. RESULTS: All patients showed heterozygous mutations of ELA2. Flow cytometric analysis demonstrated no differences in the frequency of CD34, Kit, and G-CSFR expression between CyN patients and normal subjects. Significant differences in granulocyte/macrophage (GM)-colony formation of CD34(+)/Kit(+) cells were observed among CyN patients, SCN patients, and normal subjects in response to hematopoietic factors. Impaired granulopoiesis was found in both CD34(+)/Kit(+)/G-CSFR(+) and CD34(+)/Kit(+)/G-CSFR- cells in patients with CyN, whereas this impairment was observed only in CD34(+)/Kit(+)/G-CSFR(+) cells in SCN patients, as previously reported. The mRNA expression of granular enzymes in myeloid precursors and the transcription levels during myeloid cell differentiation in CyN patients were comparable to those in normal subjects, in contrast to the abnormal transcription of granular enzymes in SCN patients. INTERPRETATION AND CONCLUSIONS: These results suggest that the underlying granulopoietic abnormalities differ between CyN and SCN, and emphasize the presence of additional genetic pathophysiology specific to each disease.

Agranulocytosis↗
PubMed2005

Comparison of directional coronary atherectomy-based intervention and stenting alone in ostial lesions of the left anterior descending artery.

BACKGROUND: Balloon angioplasty yields suboptimal results and increases the rate of restenosis in the ostium of the left anterior descending coronary artery (LAD). Several non-balloon devices have been used to improve the outcome of dilatation of such lesions. METHODS: This investigation retrospectively compared the results of a directional atherectomy (DCA)-based intervention and stenting alone on the ostial lesions of the LAD, and the effect on the left circumflex artery (LCX) ostium. Sixty-five patients with a successful angioplasty of LAD ostial lesions were studied. Patients were divided into 2 groups: group I (DCA, n = 34) and group II (stenting, n = 31). RESULTS: After intervention and at the 3-month follow-up, group I exhibited a larger minimal lumen diameter (MLD), smaller-diameter stenosis, and a lower loss index than group II. At 6 months, group I showed a lower cumulative restenosis rate of 32% as compared to 48% for group II (p = 0.04). In group I, the MLD of the LCX ostium had not changed after DCA or at follow-up. In contrast, the MLD of the LCX was significantly reduced with stenting alone and during follow-up (p < 0.01). The strategy of optimal debulking plus stenting exhibited a restenosis rate of 9%, in contrast to 33% in the optimal debulking alone strategy (p = 0.05) after 3 months. CONCLUSIONS: During the intervention for LAD ostial lesions, the DCA-based strategy seemed to be superior compared to stenting alone both in terms of acute and late target lesion revascularization and in terms of the risk of plaque shifting. The best results however were obtained when optimal DCA was combined with stenting.

Adult↗
PubMed2004

Stenting alone versus debulking and debulking plus stent in branch ostial lesions of native coronary arteries.

Angioplasty of branch ostial stenosis is associated with a high complication and restenosis rate. Previous investigations have demonstrated various treatments. However, the ideal strategy for treating branch ostial lesion remains uncertain. This investigation attempted to compare the acute, late results of stenting alone and debulking-based strategies in branch ostial lesions of native coronary arteries. Notably, various debulking strategies exist. This investigation also analyzed the acute and long-term results of the different treatments. In this study, we examined 86 patients with angina pectoris or exercise-induced ischemia and successful angioplasty of branch ostial lesions in native coronary arteries. The lesions were divided into two groups based on the angioplasty device used: group I (debulking devices, n=44) and group II (stenting alone, n=42). Procedural success and in-hospital complications were similar in both groups (P not significant). Following intervention, group I patients tended to show a smaller area of stenosis (42.3% +/- 9.9% vs 48.2% +/- 6.2%, P=0.05) and a smaller plaque-media cross-sectional area (6.05 +/- 1.87 vs 7.07 +/- 1.79 mm2, P=0.01) than group II. Furthermore, at 3 months' follow-up, group I exhibited a larger minimal lumen diameter (MLD) (2.30 +/- 0.91 vs 1.86 +/- 0.80 mm, P=0.03) than group II. Regarding the angiographic and clinical outcomes, group I displayed a restenosis rate of 32% (14/44), compared with 41% (17/42) in group II (P=0.40). Even during the 6-month follow-up, group I had a lower cumulative restenosis rate of 40% (17/43), compared with 60% (22/37) in group II ( P=0.04). The minimal luminal diameter of the ostium had not changed after directional coronary atherectomy or at follow-up. In contrast, MLD of another ostium was significantly reduced during stenting alone and at follow-up (P <0.01). When subgroups were studied, a debulking followed by stent group achieved a larger acute lumen gain than a debulking alone group (2.57 +/- 0.59 vs 2.32 +/- 0.55 mm, P=0.04). The optimal debulking plus stent subgroup had a restenosis rate of 9% (1/11) compared with 33% (6/18) in the optimal debulking alone group (P=0.05). The optimal debulking plus stent group also had a lower cumulative restenosis rate at 6 months than the optimal debulking alone group (9% vs 44%, P=0.04). Guided by intravascular ultrasound, atherectomy-based intervention appears superior to stenting alone for treating branch ostial lesions. Directional coronary atherectomy did not cause the narrowing of another ostium. However, optimal debulking followed by stenting minimized the restenosis and target lesion revascularization rates.

Aged↗
PubMed2004

Novel technique using intravascular ultrasound-guided guidewire cross in coronary intervention for uncrossable chronic total occlusions.

The experience of using a novel application of intravascular ultrasound (IVUS)-guided percutaneous coronary interventions for chronic total occlusions is reported in 2 cases. In the first case, an IVUS catheter was advanced into a side branch to identify the entry point of the major branch. In the second case, IVUS-guided penetration of the guidewire from the false lumen to the true lumen after causing a dissection was successful.

Aortic Dissection↗
PubMed2004

The influence of diabetes mellitus on plaque volume and vessel size in patients undergoing percutaneous coronary intervention.

We evaluated the influence of diabetes on plaque volume and vessel size at a reference segment in diabetic patients undergoing percutaneous coronary intervention using both angiograms and quantitative intravascular ultrasound. A total of 344 patients with 449 de novo coronary lesions including 97 diabetics (133 lesions) who underwent elective percutaneous coronary intervention under intravascular ultrasound guidance were included in this study. Eleven diabetic patients (19 lesions) received insulin and 52 patients (77 lesions) oral hypoglycemic drugs. The other 34 patients (37 lesions) received diet/exercise therapy alone. We measured vessel area (VA) and lumen area (LA) at proximal and distal reference segments by intravascular ultrasound, which were averaged. Plaque area (VA-LA) and % plaque area (100 x plaque area/VA) were subsequently calculated. Although VA was similar between diabetic and non-diabetic patients (13.46 +/- 4.49 mm2 in diabetics versus 14.11 +/- 5.24 mm2 in non-diabetics, P = 0.214), LA was smaller (6.51 +/- 2.63 mm2 versus 7.38 +/- 3.08 mm2, P = 0.004) and % PA was larger (50.4 +/- 11.7 versus 46.5 +/- 11.3, P < 0.001) in diabetic patients, especially the group receiving a hypoglycemic drug or insulin. VA, LA, and % PA were similar between patients with and without insulin treatment. These results potentially might cause undersized device selection without intravascular ultrasound guidance.

Aged↗
PubMed2003

Effect of recanalization of chronic total occlusions on global and regional left ventricular function in patients with or without previous myocardial infarction.

Previous studies have demonstrated improvement of regional wall motion and global left ventricular function after successful recanalization of chronic total occlusion in coronary artery. However, the difference of benefits of recanalization between infarct site and noninfarct site is unknown. This study assessed the changes in left ventricular ejection fraction, regional wall motion after successful angioplasty of chronic total occlusions with or without previous myocardial infarction. This study also evaluated the factors that influenced the outcome of left ventricular function. We retrospectively studied 75 patients with a successfully recanalized chronic total occlusion in native coronary artery. Left ventriculograms were obtained at baseline and after 6 months. Global and regional left ventricular function were determined. The patients were divided into two groups. Group 1 comprised patients without previous myocardial infarction in the territories of total occlusion vessel that was recanalized. Group 2 comprised patients with previous myocardial infarction in the territories of total occlusion vessel that was recanalized. Left ventricular ejection fraction increased from 53.2% +/- 16.3% at baseline to 57.3% +/- 20.1% at 6-month follow-up in the whole group (P = 0.001). In group 1 patients, the evolution of left ventricular (LV) ejection fraction increased from 59.5% +/- 13.7% to 67.3% +/- 14.6% (P < 0.001). In group 2 patients, the evolution of LV ejection fraction increased, but not significantly, from 48.9% +/- 16.2% to 50.5% +/- 16.9% (P = NS). The evolution of LV ejection fraction increased from 47.6% +/- 17.4% to 50.8% +/- 17.5% (P < 0.05) in the subgroup of recanalization in infarct-related vessel that had rich collateral circulation and had long-term patency. The regional wall motion all significantly improved in group 1 patients (P < 0.05). The regional wall motion did not change in group 2 patients (P = NS). The influence of recanalization of chronic coronary occlusions on the improvement of left ventricular global function was different between myocardial infarction and nonmyocardial infarction patients. The left ventricular function did not improve in myocardial infarction patient. Regional wall motion improved in patients without previous myocardial infarction. For reliable improvement of left ventricular function after recanalization of chronic total occlusions, evidence (not only by symptom or treadmill test) of viable myocardium in recanalized vessel is important. It is also important to keep patency of infarct-related vessel that has good collateral circulation for improving the left ventricular function.

Aged↗
PubMed2003

Evaluation of the PercuSurge Guardwire Plus Temporary Occlusion and Aspiration System during primary angioplasty in acute myocardial infarction.

Thirty patients with acute myocardial infarction (AMI) underwent primary angioplasty under distal protection of PercuSurge GuardWire Plus Temporary Occlusion and Aspiration System. Before angioplasty, protection of the distal circulation was achieved with the system, followed by balloon angioplasty and/or stenting and debris aspiration. Technical device success was 100%. Distal occlusion was well tolerated in all patients. Mean total distal occlusion time was 7.3 +/- 5.4 min. Macroscopically visible debris was aspirated from 29 cases (96.7%). Postprocedural Thrombolysis in Myocardial Infarction flow grade 3 was achieved in all cases (100%, vs. 16.7% at baseline). Myocardial blush flow grade 3 was achieved in 26 cases (86.7%). Regression of ST segment elevation >/= 50% was shown in 23 cases (76.7%). No patient developed angiographic evidence of no-reflow or distal embolization. Both angiographic and procedural success were 100%. The system is feasible, safe, and effective for distal protection against embolism during primary angioplasty in AMI.

Aged↗
PubMed2003

Dysregulation of transcriptions in primary granule constituents during myeloid proliferation and differentiation in patients with severe congenital neutropenia.

We examined the expression of granule constituent genes in myeloid progenitor cells during proliferation and differentiation in patients with severe congenital neutropenia (SCN). The heterozygous mutation of the neutrophil elastase gene was identified in two of four patients. The CD34+/granulocyte-colony stimulating factor receptor (G-CSFR)+ cells of SCN patients showed defective responsiveness to G-CSF in serum-deprived culture. The CD34+/G-CSFR+ cells expressed low levels of the granule constituent mRNAs. The transcription levels of primary granule enzyme genes in CD34+/G-CSFR+ cells were gradually enhanced and then decreased when cells were induced toward myeloid lineage with G-CSF in normal subjects. However, the primary up-regulation and the following down-regulation of these enzyme transcriptions were not clearly observed in SCN patients. No differences in expressions of the lactoferrin gene were seen between normal subjects and patients with SCN. We hypothesize that the abnormal regulation of the transcription in primary granule constituents might involve the defective proliferation and differentiation of myeloid cells in patients with SCN.

Bone Marrow Cells↗