Biomedical subjects

Kengo Tanabe

Publications and source records attributed to Kengo Tanabe.

At least 19 recordsLinked to original sources

PubMed2026

Genome-Wide Association Study of Contrast Media Hypersensitivity in Japanese Patients.

Iodinated contrast media (ICM), commonly used in radiological tests such as coronary angiography, can cause hypersensitivity reactions (HSRs). The mechanism of ICM HSRs is thought to be complex; while IgE-mediated allergic reactions appear to be involved, the details remain unclear. This study aims to elucidate the pathogenesis of ICM HSRs through genetic analysis. To date, a few case-control studies have been conducted exclusively on East Asians, but the results have been inconclusive and have not been replicated.We conducted a multistage GWAS for ICM HSRs in Japanese individuals. The study population comprised 153 cases with ICM HSRs (ranging from mild to severe form), 632 controls with no history of ICM-induced allergies, and < 38,721 individuals from the general population. We identified genome-wide significant association signals in the HLA region and also found that these signals originated from the three HLA alleles-B*52:01, C*12:02, DRB1*15:02-previously reported in a Korean candidate gene study. Using instrumental variable analysis with a polygenic score for pediatric asthma (PGSasthma) as a proxy, we demonstrated that ICM HSRs are associated with the allergic predisposition thought to be shared by asthma and ICM HSRs. There was a significant difference in the distribution of PGSasthma between ICM HSR patients and non-disease controls (per-SD odds ratio: 1.26, P = 0.021).Our genome-wide approach shows that HLA alleles are among the genetic factors underlying ICM HSRs. Furthermore, it provides evidence for the potential usefulness of predicting the risk of developing ICM HSRs based on allergic predisposition.

Allergic predisposition↗

PubMed2007

Impact of renal insufficiency on clinical and angiographic outcomes following percutaneous coronary intervention with sirolimus-eluting stents.

BACKGROUND: Sirolimus-eluting stents (SES) have been demonstrated to reduce restenosis. However, there have been few studies evaluating the impact of renal insufficiency on the angiographic as well as clinical outcomes after SES implantation. METHODS: This study was composed of 304 consecutive patients having 361 lesions who underwent percutaneous coronary intervention with SES. The patients were divided into 3 groups according to renal function (group 1 [n = 204]; creatinine clearance (Ccr) > or = 60 ml/min, group 2 [n = 69]; Ccr < 60 ml/min, group 3 [n = 31]; hemodialysis). Clinical and angiographic follow-up were evaluated at 8 months. RESULTS: Clinical follow-up was obtained in all patients and angiographic follow-up was obtained in 283 patients (93.1%). Patients in group 3 showed a higher incidence of previous coronary artery bypass graft surgery, and there were more female gender, hypertensive, and less hyperlipidemia in this group. Late lumen loss at 8 months was significantly different among the 3 groups (group 1; 0.16 +/- 0.46 mm, group 2; 0.44 +/- 0.62 mm, group 3; 0.81 +/- 0.88 mm, P < 0.0001). Major adverse cardiac events (MACE) were documented in 22 patients (10.8%) in group 1, 13 patients (18.8%) in group 2, and 12 patients (38.7%) in group 3, respectively (P = 0.0002). CONCLUSION: Neointimal growth following SES implantation is more pronounced in patients with renal insufficiency, especially those undergoing dialysis, compared with patients with normal renal function. Regardless of the beneficial effect of SES, the increased risk of MACE mainly due to high incidence of target vessel revascularization in the subgroup of patients with renal insufficiency should be taken into account.

Aged↗

PubMed2007

Incidence and clinical impact of coronary stent fracture after sirolimus-eluting stent implantation.

BACKGROUND: Stent fracture is one of the possible causes of restenosis after sirolimus-eluting stents (SES) implantation. The aim of our study was to evaluate the prevalence and clinical impact of coronary stent fracture after SES implantation. METHODS: From our prospective institutional database, 280 patients were treated solely with SES from August 2004 to June 2005. Among the 280 patients, 256 patients with a total of 307 lesions underwent follow-up angiography on an average of 240 days after the procedure. RESULTS: Stent fractures were observed in eight (2.6%) lesions. Of the eight lesions with stent fracture, five were located in the right coronary artery (RCA), two in the saphenous vein (SV) graft, and one in the left anterior descending coronary artery. The stent fractures were all in the locations that served as hinges during vessel movement in the cardiac contraction cycle. Seven of the eight stent fractures were adjacent to the edge of previously implanted or overlapped stent. Significant multivariate predictors of stent fracture were SV graft location (Odds ratio 35.88; 95% confidence interval 2.73-471.6, P = 0.006), implanted stent length (Odds ratio 1.04; 95% confidence interval 1.01-1.07, P = 0.02), and RCA location (Odds ratio 10.00; 95% confidence interval 1.11-89.67, P = 0.04). In-stent binary restenosis rate was 37.5% and target lesion repeat revascularization rate was 50.0% in patients with stent fracture. CONCLUSIONS: Stent fracture was likely to be affected by mechanical stress provoked by rigid structures and hinge points. Stent fracture might be associated with the high incidence of target lesion revascularization.

Aged↗

PubMed2006

Noncardiac findings in cardiac imaging with multidetector computed tomography.

OBJECTIVES: We investigated the frequency of the noncardiac findings in cardiac imaging with multidetector computed tomography (MDCT). BACKGROUND: Multidetector computed tomography is an accepted new tool to evaluate the heart. In cardiac MDCT scans, organs other than the heart are also irradiated, but usually not assessed. METHODS: A total of 503 patients underwent cardiac imaging with 16- or 64-slice MDCT. Cardiologists assessed the heart, while radiologists reviewed the other organs. RESULTS: A total of 346 new, noncardiac findings were identified in 292 patients (58.1%). A total of 114 patients (22.7%) had clinically significant findings including 4 cases of malignancy (0.8%). CONCLUSIONS: There were a significant number of noncardiac findings in cardiac MDCT. To avoid missing clinically important findings, physicians who analyze cardiac MDCT scan--either radiologists or cardiologists--should carefully evaluate all the organs irradiated in the scan.

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PubMed2006

Prolonged QRS duration and severity of mitral regurgitation are unfavorable prognostic markers of heart failure in patients with nonischemic dilated cardiomyopathy.

BACKGROUND: The goal of the present study was to identify predictors of event-free survival in nonischemic dilated cardiomyopathy (NIDCM) patients after administration of angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB) and beta-blockers. METHODS AND RESULTS: The study group comprised 78 consecutive patients with NIDCM between 1997 and 2002. NIDCM was defined as ejection fraction (EF) <0.40 and left ventricular end-diastolic diameter (LVEDD) >55 mm on echocardiography and normal coronary angiography. The mean EF and LVEDD was 26.3 +/- 10.5%, and 62.9 +/- 7.1 mm, respectively. Patients were treated with optimal medical therapy including ACEI/ARBs and/or beta-blockers and followed up for 35.6 +/- 27.8 months. The primary endpoint was either cardiac death or hospitalization because of deterioration of heart failure. Cox's regression analysis was used to establish the association of age, sex, EF, LVEDD, left atrial diameter, cardiac index, pulmonary capillary wedge pressure, QRS duration, severity of mitral regurgitation, body mass index, New York Heart Association class and the presence of atrial fibrillation with these events. During follow-up, 23 patients reached the primary endpoint. In a multivariate analysis, EF (chi-square 5.74, p=0.0166), severity of mitral regurgitation (chi-square 12.31, p=0.0004), and QRS duration (chi-square 11.20, p=0.0008) remained significant predictors. CONCLUSION: In NIDCM patients, prolonged QRS duration is a high risk factor for remodeling and unfavorable events. The severity of mitral regurgitation was also a strong risk predictor.

Aged↗

PubMed2006

[Technical evolution of the stent].

Percutaneous coronary intervention has been hampered by restenosis since its inception. Many research projects including the use of various devices and systemic drug administration have shown disappointing results. Recently, the advent of drug-eluting stents has reduced incidence of restenosis compared with bare metal stents. This article provides an overview of the developments of drug-eluting stents, their clinical impact on the treatment of acute coronary syndrome, and their future perspectives.

Angina, Unstable↗

PubMed2005

Prevalence of carotid artery stenosis in patients with coronary artery disease in Japanese population.

BACKGROUND AND PURPOSE: Prevalence of carotid artery stenosis in patients with coronary artery disease (CAD) is unknown in Japanese population. METHODS: The study populations consisted of 632 consecutive patients who underwent coronary angiography because of suspicion of CAD. All patients underwent carotid ultrasonography to screen carotid artery stenosis before coronary angiography. We defined echographic carotid stenosis as area stenosis of >50% or peak systolic velocity of >200 cm/s. RESULTS: Echographic carotid stenosis was observed in 124 patients (19.6%). Coronary angiography revealed 433 patients had CAD. Prevalence of echographic carotid artery stenosis was 14 of 199 (7.0%), 18 of 124 (14.5%), 28 of 131 (21.4%), and 64 of 178 (36.0%) in patients with 0-, 1-, 2-, and 3-vessel CAD, respectively (P<0.0001). The prevalence rate with carotid stenosis and CAD was 25.4%. Multivariate stepwise logistic regression analysis showed that age and the extent of CAD were independently related to the presence of carotid stenosis (P=0.0002 and <0.0001, respectively). CONCLUSIONS: Prevalence of carotid stenosis in patients with CAD is high in Japan as well as in Western countries. Screening of carotid artery stenosis is recommended especially in older patients with multivessel CAD.

Adult↗

PubMed2005

Incomplete stent apposition after implantation of paclitaxel-eluting stents or bare metal stents: insights from the randomized TAXUS II trial.

BACKGROUND: The clinical impact of late incomplete stent apposition (ISA) for drug-eluting stents is unknown. We sought to prospectively investigate the incidence and extent of ISA after the procedure and at 6-month follow-up of paclitaxel-eluting stents in comparison with bare metal stents (BMS) and survey the clinical significance of ISA over a period of 12 months. METHODS AND RESULTS: TAXUS II was a randomized, double-blind study with 536 patients in 2 consecutive cohorts comparing slow-release (SR; 131 patients) and moderate-release (MR; 135 patients) paclitaxel-eluting stents with BMS (270 patients). This intravascular ultrasound (IVUS) substudy included patients who underwent serial IVUS examination after the procedure and at 6 months (BMS, 240 patients; SR, 113; MR, 116). The qualitative and quantitative analyses of ISA were performed by an independent, blinded core laboratory. More than half of the instances of ISA observed after the procedure resolved at 6 months in all groups. No difference in the incidence of late-acquired ISA was observed among the 3 groups (BMS, 5.4%; SR, 8.0%; MR, 9.5%; P=0.306), with a similar ISA volume (BMS, 11.4 mm3; SR, 21.7 mm3; MR, 8.5 mm3; P=0.18). Late-acquired ISA was the result of an increase of vessel area without change in plaque behind the stent. Predictive factors of late-acquired ISA were lesion length, unstable angina, and absence of diabetes. No stent thrombosis occurred in the patients diagnosed with ISA over a period of 12 months. CONCLUSIONS: The incidence and extent of late-acquired ISA are comparable in paclitaxel-eluting stents and BMS. ISA is a pure IVUS finding without clinical repercussions.

Aged↗

PubMed2005

Rapid diagnosis and management of intraoperative myocardial infarction during valvular surgery: using intraoperative transesophageal echocardiography followed by emergency coronary artery bypass grafting without coronary angiography.

A 68-year-old man was admitted to undergo elective mitral valve surgery. Although the preoperative coronary angiography was normal, the patient suffered a myocardial infarction that resulted in untreatable collapsed hemodynamics. After inferring the responsible occluded coronary artery from the segmental wall motion abnormality detected in intraoperative transesophageal echocardiography, together with the anatomy found in preoperative coronary angiography, we performed an emergency coronary artery bypass graft surgery without a new angiography. This procedure resulted in survival of a potentially life-threatening situation. In selected cases, this therapeutic strategy may lead to reduction of mortality as a result of the intraoperative myocardial infarction.

Aged↗

PubMed2005

[Diagnosis and Intervention for calcified coronary artery disease--role of multi-slice CT].

Calcification has been well known to exist in atherosclerotic lesions from 19th century. The mechanisms of calcification are still unknown. Coronary stenoses can be treated by percutaneous coronary intervention using drug eluting stents at present. To the contrary, calcified coronary lesions are still difficult to be treated due to stent unexpansion despite of high pressure dilatation. Recent development of multi-slice CT (MDCT) has made it possible to diagnose coronary stenoses non-invasively. Coronary calcification is easily detected using MDCT, however, quantification of stenosis is difficult in calcified lesions.

Calcinosis↗

PubMed2004

Effectiveness of sirolimus-Eluting stent implantation for coronary narrowings <50% in diameter.

The long-term efficacy of percutaneous coronary intervention for mildly obstructive coronary narrowings is limited by the occurrence of restenosis, limiting the applicability of this therapy for these lesions. The present study reports on a consecutive series of 20 patients treated with sirolimus-eluting stent implantation for 23 angiographically mild de novo lesions (defined as a diameter stenosis <50% by quantitative coronary angiography). At a mean follow-up of 399 +/- 120 days, the survival-free of major adverse events was 95%, with no patient requiring target lesion revascularization.

Coronary Angiography↗

PubMed2004

Restenosis rates following bifurcation stenting with sirolimus-eluting stents for de novo narrowings.

The percutaneous treatment of coronary bifurcation stenoses is hampered by an increased rate of subsequent restenosis. The present study reports on the outcomes of a consecutive series of 58 patients with 65 de novo bifurcation stenoses treated with sirolimus-eluting stent implantation in both the main vessel and side branch. At 6 months, the incidence of major adverse cardiac events was 10.3% (1 death and 5 target lesion revascularizations) with no episodes of acute myocardial infarction or stent thrombosis.

Angioplasty, Balloon, Coronary↗

PubMed2004

Significant reduction in restenosis after the use of sirolimus-eluting stents in the treatment of chronic total occlusions.

OBJECTIVES: The aim of this study was to assess sirolimus-eluting stent (SES) implantation for the treatment of chronic total coronary occlusions (CTO). BACKGROUND: Long-term results after percutaneous coronary intervention (PCI) in the treatment of CTOs is hindered by a significant rate of restenosis and reocclusion. In the treatment of relatively simple nonocclusive lesions, SESs have shown dramatically reduced restenosis rates compared with bare metal stents (BMS), but whether these results are more widely applicable is unknown. METHODS: From April 2002, all patients at our institution were treated with SES as the device of choice during PCI. During the first six months, 563 patients were treated solely with SES, with treatment of a de novo CTO in 56 (9.9%). This CTO cohort was compared with a similar group of patients (n = 28) treated in the preceding six-month period with BMS. RESULTS: At one year, the cumulative survival-free of major adverse cardiac events was 96.4% in the SES group versus 82.8% in the BMS group, p < 0.05. At six-month follow-up, 33 (59%) patients in the SES group underwent angiography with a binary restenosis rate (>50% diameter stenosis) of 9.1% and in-stent late loss of 0.13 +/- 0.46 mm. One patient (3.0%) at follow-up was found to have reoccluded the target vessel. CONCLUSIONS: The use of SESs in the treatment of chronic total coronary occlusions is associated with a reduction in the rate of major adverse cardiac events and restenosis compared with BMS.

Angioplasty, Balloon, Coronary↗

PubMed2004

Incidence of thrombotic stent occlusion during the first three months after sirolimus-eluting stent implantation in 500 consecutive patients.

Sirolimus-eluting stents have been used in our institution for all percutaneous interventions, without clinical or anatomic exclusion criteria, as part of the Rapamycin-Eluting Stent Evaluated At Rotterdam Cardiology Hospital registry. We analyzed the incidence of (sub)acute stent thrombosis after sirolimus-eluting stent implantation in an unselected population of 510 consecutive patients. At 3-month follow-up, (sub)acute stent thrombosis was diagnosed in 2 patients (0.4%) 6 hours and 11 days after the procedure, respectively. These cases occurred in diabetic women with complex coronary lesions. Intravascular ultrasound examination showed inadequate stent expansion and uncovered distal dissection as possible mechanical explanations for the thrombosis.

Angioplasty, Balloon, Coronary↗

PubMed2004

Very long sirolimus-eluting stent implantation for de novo coronary lesions.

Long-length stenting has a poor outcome when bare metal stents are used. The safety and efficacy of the sirolimus-eluting stent (SES) in long lesions has not been evaluated. Therefore, the aim of the present study was to evaluate the clinical and angiographic outcomes of SES implantation over a very long coronary artery segment. Since April 2002, all patients treated percutaneously at our institution received a SES as the device of choice as part of the Rapamycin Eluting Stent Evaluated At Rotterdam Cardiology Hospital (RESEARCH) registry. During the RESEARCH registry, stents were available in lengths of 8, 18, and 33 mm. The present report includes a predefined study population consisting of patients treated with >36-mm-long stented segments. Patients had a combination of >or=2 overlapping stents at a minimum length of 41 mm (i.e., one 33-mm SES overlapping an 8-mm SES) to treat native de novo coronary lesions. The incidence of major cardiac adverse events (death, nonfatal myocardial infarction, and target lesion revascularization) was evaluated. The study group comprised 96 consecutive patients (102 lesions). Clinical follow-up was available for all patients at a mean of 320 days (range 265 to 442). In all, 20% of long-stented lesions were chronic total occlusions, and mean stented length per lesion was 61.2 +/- 21.4 mm (range 41 to 134). Angiographic follow-up at 6 months was obtained in 67 patients (71%). Binary restenosis rate was 11.9% and in-stent late loss was 0.13 +/- 0.47 mm. At long-term follow-up (mean 320 days), there were 2 deaths (2.1%), and the overall incidence of major cardiac events was 8.3%. Thus, SES implantation appears safe and effective for de novo coronary lesions requiring multiple stent placement over a very long vessel segment.

Aged↗

PubMed2004

Treatment of very small vessels with 2.25-mm diameter sirolimus-eluting stents (from the RESEARCH registry).

A total of 91 patients with 112 lesions received 2.25-mm sirolimus-eluting stents (SESs), and these lesions were compared with those treated with SESs of > or =2.5-mm diameter in the same procedure (n = 109). The reference diameters were 1.88 +/- 0.34 and 2.52 +/- 0.57 mm, respectively (p <0.01). At follow-up, the late lumen loss was 0.07 +/- 0.48 mm for the 2.25-mm SES versus 0.03 +/- 0.38 mm for the larger SES (p = 0.5), and the binary restenosis rate was 10.7% versus 3.9%, respectively (p = 0.1). The 12-month target lesion revascularization rate was 5.5%. In conclusion, 2.25-mm SESs were associated with low rates of clinical and angiographic late complications.

Aged↗

PubMed2004

Vascular responses at proximal and distal edges of paclitaxel-eluting stents: serial intravascular ultrasound analysis from the TAXUS II trial.

BACKGROUND: On the basis of brachytherapy experience, edge stenosis has been raised as a potential limitation for drug-eluting stents. We used serial intravascular ultrasound (IVUS) to prospectively analyze vessel responses in adjacent reference segments after implantation of polymer-controlled paclitaxel-eluting stents. METHODS AND RESULTS: TAXUS II was a randomized, double-blind trial with 2 consecutive patient cohorts that compared slow-release (SR) and moderate-release (MR) paclitaxel-eluting stents with control bare metal stents (BMS). By protocol, all patients had postprocedure and 6-month follow-up IVUS. Quantitative IVUS analysis was performed by an independent core laboratory, blinded to treatment allocation, in 5-mm vessel segments immediately proximal and distal to the stent. Serial IVUS was available for 106 SR, 107 MR, and 214 BMS patients. For all 3 groups, a significant decrease in proximal-edge lumen area was observed at 6 months. The decrease was comparable (by ANOVA, P=0.194) for patients in the SR (-0.54+/-2.1 mm2) and MR (-0.88+/-1.9 mm2) groups compared with the BMS (-1.02+/-1.9 mm2) group. For the distal edge, a significant decrease in lumen area was only observed with BMS (-0.91+/-2.0 mm2, P<0.0001); this decrease was significantly attenuated with SR (0.08+/-2.0 mm2) and MR (-0.19+/-1.7 mm2) stents (P<0.0001 by ANOVA). Negative vessel remodeling was observed at the proximal (-0.48+/-2.2 mm2, P=0.011) but not the distal edges of BMS and at neither edge of SR or MR stents. CONCLUSIONS: The marked reduction in in-stent restenosis with SR or MR stents is not associated with increased edge stenosis at 6-month follow-up IVUS. In fact, compared with BMS, there is instead a significant reduction in late lumen loss at the distal edge with TAXUS stents.

Coronary Restenosis↗

PubMed2004

Retrospective image-based gating of intracoronary ultrasound images for improved quantitative analysis: the intelligate method.

Quantitative analysis of intracoronary ultrasound (ICUS) studies is performed on a series of tomographic cross-sectional ICUS images acquired during a motorized 0.5 mm/sec catheter pullback. Catheter displacement in the vascular lumen during the cardiac cycle causes an anatomically shuffled ICUS study, which results in a sawtooth-shaped appearance of the coronary segment in longitudinal reconstructed views in quantitative coronary ultrasound software packages. This hampers contour detection and leads to a laborious time-consuming semiquantitative analysis process that may produce inaccurate results. To solve these problems, in the past, online ECG-gated acquisition hardware has been applied. This article describes a novel image-based gating method called Intelligate, which features automatic retrospective selection of end-diastolic frames from videotaped or digitally stored ICUS studies. Our evaluation shows that there are no quantitative differences between analysis results of hardware ECG-gated and Intelligated ICUS studies.

Coronary Circulation↗