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23
result(s) for
"Shimamura, Kunihiro"
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Impact of cavotricuspid isthmus depth on the ablation index for successful first-pass typical atrial flutter ablation
2021
Cavotricuspid isthmus (CTI) linear ablation has been established as the treatment for typical atrial flutter. Recently, ablation index (AI) has emerged as a novel marker for estimating ablation lesions. We investigated the relationship between CTI depth and ablation parameters on the procedural results of typical atrial flutter ablation
.
A total of 107 patients who underwent CTI ablation were retrospectively enrolled in this study. All patients underwent computed tomography before catheter ablation. From the receiver-operating curve, the best cut-off value of CTI depth was < 4.1 mm to predict first-pass success. Although the average AI was not different between deep CTI (DC; CTI depth ≥ 4.1) and shallow CTI (SC; CTI depth < 4.1), DC required a longer ablation time and showed a lower first-pass success rate (
p
< 0.01). In addition, the catheter inversion technique was more frequently required in the DC (
p
< 0.01). The lowest AI sites of the first-pass CTI line were determined in both the ventricular (2/3 segment of CTI) and inferior vena cava (IVC, 1/3 segment of CTI) sides. The best cut-off values of the weakest AIs at the ventricular and IVC sides for predicting first-pass success were > 420 and > 386, respectively. Among patients with these cut-off values, the first-pass success rate was 89% in the SC and 50% in the DC (
p
< 0.01). Although ablation parameters were not significantly different, the first-pass success rate was lower in the DC than in the SC. Further investigation might be required for better outcomes in deep CTIs.
Journal Article
Impact of left ventricular ejection fraction and preoperative hemoglobin level on perioperative adverse cardiovascular events in noncardiac surgery
2021
The prediction of a perioperative adverse cardiovascular event (PACE) is an important clinical issue in the medical management of patients undergoing noncardiac surgery. Although several predictors have been reported, simpler and more practical predictors of PACE have been needed. The aim of this study was to investigate the predictors of PACE in noncardiac surgery. We retrospectively analyzed 723 patients who were scheduled for elective noncardiac surgery and underwent preoperative examinations including 12-lead electrocardiography, transthoracic echocardiography, and blood test. PACE was defined as cardiac death, non-fatal myocardial infarction, unstable angina, congestive heart failure, arrhythmia attack that needs emergency treatment (rapid atrial fibrillation, ventricular tachycardia, and bradycardia), acute pulmonary embolism, asystole, pulseless electrical activity, or stroke during 30 days after surgery. PACE occurred in 54 (7.5%) of 723 patients. High-risk operation (11% vs. 3%,
p
= 0.003) was more often seen, left ventricular ejection fraction (LVEF) (55 ± 8% vs. 60 ± 7%,
p
= 0.001) and preoperative hemoglobin level (11.8 ± 2.2 g/dl vs. 12.7 ± 2.0 g/dl,
p
= 0.001) were lower in patients with PACE compared to those without PACE. By multivariate logistic regression analysis, high-risk operation (odds ratio (OR): 7.05, 95% confidence interval (CI) 2.16–23.00,
p
= 0.001), LVEF (OR 1.06, every 1% decrement, 95% CI 1.03–1.09,
p
= 0.001), and preoperative hemoglobin level (OR 1.22, every 1 g/dl decrement, 95% CI 1.07–1.39,
p
= 0.003) were identified as independent predictors of PACE. Receiver operating characteristic analysis demonstrated that LVEF of 58% (sensitivity = 80%, specificity = 61%, area under the curve (AUC) = 0.723) and preoperative hemoglobin level of 12.2 g/dl (sensitivity = 63%, specificity = 64%, AUC = 0.644) were optimal cut-off values for predicting PACE. High-risk operation, reduced LVEF, and reduced preoperative hemoglobin level were independently associated with PACE in patients undergoing noncardiac surgery.
Journal Article
Real-time venography-guided extrathoracic puncture technique for cardiovascular implantable electronic device implantation
by
Kuroi, Akio
,
Kubo, Takashi
,
Taruya, Akira
in
Biomedical Engineering and Bioengineering
,
Cardiac Surgery
,
Cardiology
2022
Central venous access is an essential technique for cardiovascular implantable electronic device (CIED) implantation, and the use of axillary vein approach has recently been increasing. This study sought to examine whether real-time venography-guided extrathoracic puncture facilitates the procedure. We retrospectively analyzed 179 consecutive patients who underwent CIED implantation using the axillary vein puncture method. Patients were divided into two groups: the conventional method group (CG,
n
= 107) and the real-time venography-guided group (RG,
n
= 82). The application of real-time venography was at the discretion of individual operators. Operators with experience of less than 50 CIED implantations were defined as inexperienced operators in this study. Puncture duration and number of attempts were significantly less in the RG group than in the CG group (283 ± 198 vs. 421 ± 361 s,
p
< 0.01, and 3.19 ± 2.00 vs. 4.18 ± 2.85,
p
< 0.01). These benefits of real-time venography were observed in inexperienced operators, but not in experienced operators. In addition, the success rate without extra attempts at puncture was higher in the RG group (54% vs. 32%,
p
< 0.01). Although the total amount of contrast medium was higher in the RG group (16.3 ± 4.1 mL vs. 11.9 ± 6.6 mL,
p
< 0.01), serum levels of creatinine pre- and post-operation were not different in the two groups (
p
= NS). We concluded that real-time venography is a safe and effective method for axillary vein puncture, especially in inexperienced operators.
Journal Article
Usefulness of optical coherence tomography with angiographic coregistration in the guidance of coronary stent implantation
by
Tu, Shengxian
,
Higashioka, Daisuke
,
Kubo, Takashi
in
Angina pectoris
,
Angiography
,
Biomedical Engineering and Bioengineering
2022
Optical coherence tomography (OCT)-angiography coregistration during stent implantation may be useful to avoid geographical mismatch and incomplete lesion coverage. Untreated lipid-rich plaque at stent edge is associated with subsequent stent edge restenosis. The present study sought to compare the frequency of untreated lipid-rich plaque at the stent edge between OCT-guided percutaneous coronary intervention (PCI) with and without OCT-angiography coregistration. We investigated 398 patients who underwent OCT-guided stent implantation (
n
= 198 in the coregistration group, and
n
= 200 in the no coregistration group). In OCT after PCI, untreated lipid-lich plaque was identified by the maximum lipid arc > 180˚ in the 5-mm stent edge segment. The PCI-targeted lesion characteristics and stent length were not different between the coregistration group and the no coregistration group. The frequency of untreated lipid-rich plaque in either proximal or distal stent edge segment was significantly lower in the coregistration group than in the no coregistration group (16% vs. 26%,
P
= 0.015). The frequency of stent-edge dissection (5% vs. 6%,
P
= 0.516) and untreated stenosis (2% vs. 3%,
P
= 0.724) was low and without significant differences between the two groups. In OCT-guided PCI, the use of OCT-angiography coregistration was associated with a reduced frequency of untreated lipid-rich plaque at stent edges. OCT-angiography coregistration has a positive impact on PCI results.
Journal Article
Noninvasive estimation of impaired left ventricular untwisting velocity by peak early diastolic intra-ventricular pressure gradients using vector flow mapping
by
Fujita, Suwako
,
Kubo, Takashi
,
Akasaka, Takashi
in
Catheters
,
Patients
,
Pressure distribution
2021
BackgroundIntroduction of vector flow mapping (VFM) based on the combination of color Doppler and speckle-tracking echocardiography provides noninvasive assessment of early diastolic intra-ventricular pressure gradient (ED-IVPG). The purpose of this study was to evaluate the value of peak ED-IVPG measurement just after aortic valve closure using VFM for noninvasive estimation of impaired LV untwisting velocity as the index of LV relaxation in the clinical setting.Methods and resultsThe study included 65 consecutive patients in whom echocardiography was performed for the assessment of LV function. We assessed peak ED-IVPG between LV apex and base by VFM analysis software. We also measured peak LV untwisting velocity and LV twisting by speckle-tracking strain analysis. Peak ED-IVPG was successfully and quickly assessed in all the study patients. Peak ED-IVPG was significantly reduced in patients with impaired peak LV untwisting velocity (< 70 degrees/s) compared with patients without impaired peak LV untwisting velocity. The receiver operating characteristic analysis showed the best cut-off value of peak ED-IVPG for determining impaired peak LV untwisting velocity was 0.40 mmHg (sensitivity 81%, specificity 74%, and area under the curve 0.81). There was a well correlation between peak ED-IVPG and peak LV untwisting velocity (r = 0.64, p < 0.0001).ConclusionsThe present results suggest that peak ED-IVPG just after aortic valve closure measured by VFM may be used as noninvasive index for estimation of impaired LV untwisting velocity in the clinical setting.
Journal Article
Very late-phase vascular response after everolimus-eluting stent implantation assessed by optical coherence tomography
by
Akasaka Takashi
,
Khalifa Amir Kh M
,
Tanimoto Takashi
in
Drug delivery
,
Evaluation
,
Implantation
2020
Long-term safety of second generation drug-eluting stents (DES) has not yet been evaluated. We sought to evaluate the very late phase (> 3 years) vascular response after second generation everolimus-eluting stent (EES) as compared with first generation sirolimus-eluting stent (SES) by using optical coherence tomography (OCT). We examined the vascular response in 39 patients with a total of 55 DESs [31 EESs (mean 54 months after stenting) and 24 first generation SES (mean 66 months after stenting)] by OCT. The frequency of lesions with any malapposed stent struts (19% vs. 46%, p = 0.035) and evagination (6% vs. 42%, p = 0.002) was significantly lower. Segments with malapposed stent struts were significantly shorter (0.4 ± 0.9 mm vs. 1.9 ± 3.5 mm, p = 0.024), maximal malapposition area and malapposition volume were significantly smaller (0.26 ± 0.38 mm2 vs. 0.95 ± 1.54 mm2, p = 0.019, and 0.78 ± 1.35 mm3 vs. 6.22 ± 15.76 mm3, p = 0.016, respectively) in EES. Compared with first generation SES, second generation EES showed more favourable vascular responses at the very late phase.
Journal Article
The relationship between timing of prasugrel pretreatment and in-stent thrombus immediately after percutaneous coronary intervention for acute coronary syndrome: an optical coherence tomography study
by
Kitabata, Hironori
,
Ota, Shingo
,
Aoki, Hiroshi
in
Acute coronary syndromes
,
Angina pectoris
,
Angiography
2018
The optimal timing of pretreatment with prasugrel in percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) is unclear. We used optical coherence tomography (OCT) to compare in-stent thrombus volume immediately after PCI between the administration of low-dose prasugrel (20 mg loading dose) at the time of diagnosis of ACS (early prasugrel:
n
= 34) and the administration of low-dose prasugrel immediately after diagnostic angiography prior to PCI for ACS (late prasugrel:
n
= 56). The durations between the administration of prasugrel and OCT in the early prasugrel group and late prasugrel group were 5.1 ± 6.5 and 0.9 ± 0.7 h, respectively (
p
< 0.001). OCT detected thrombus/plaque protrusion in all stented segments. In-stent thrombus/plaque protrusion volume (2.92 ± 1.96 vs. 6.48 ± 4.97 mm
3
,
p
< 0.001), mean in-stent thrombus/plaque protrusion area (0.13 ± 0.07 vs. 0.29 ± 0.23 mm
2
,
p
< 0.001) and maximum in-stent thrombus/plaque protrusion area (0.70 ± 0.36 vs. 1.06 ± 0.56 mm
2
,
p
< 0.001) were significantly smaller in the early prasugrel group as compared with the late prasugrel group. The administration of prasugrel at the time of diagnosis of ACS was associated with significantly reduced in-stent thrombus/plaque protrusion immediately after PCI as compared with the administration of prasugrel after the coronary angiography prior to PCI.
Journal Article
Effect of strut thickness on neointimal atherosclerotic change over an extended follow-up period (≥4 years) after bare-metal stent implantation: Intracoronary optical coherence tomography examination
by
Ozaki, Yuichi
,
Kitabata, Hironori
,
Kimura, Keizo
in
Aged
,
Angina pectoris
,
Atherosclerosis (general aspects, experimental research)
2012
Neointima inside the bare-metal stents (BMSs) can transform into atherosclerotic tissue during an extended follow-up because of a persistent inflammatory reaction to the metal. We sought to investigate whether strut thickness may impact on the atherosclerotic change in neointima 4 years or more after BMS implantation using optical coherence tomography.
Forty-six stented lesions of 41 patients with BMS ≥4 years after implantation who underwent optical coherence tomography were enrolled in the study. The strut was defined as thin when less than 100 μm and thick when ≥100 μm. According to these criteria, stents were divided into 2 groups (thin strut n = 19, thick strut n = 27). Neointimal tissue was categorized into normal neointima, characterized by a signal-rich band without signal attenuation, or lipid-laden intima, with marked signal attenuation and a diffuse border. Intimal disruption, thrombus, and neovascularization were also evaluated.
The mean period after implantation was 98.2 ± 25.8 months in the thin-strut group and 91.1 ± 22.8 months in the thick-strut group (P = .330). Lipid-laden intima (70% vs 32%, P = .016), thin-cap fibroatheroma–like intima (59% vs 16%, P = .0056), and intimal disruption (48% vs 16%, P = .031) were observed more frequently in the thick-strut group than in the thin-strut group, but no significant difference was observed in the frequency of thrombus. Although peristrut neovascularization was a common finding in both groups (thick vs thin 81% vs 79%, P = 1.000), the frequency of intraintima neovascularization tended to be higher in the thick-strut group (67% vs 42%, P = .135).
A thinner strut thickness may have favorable effects on neointimal atherosclerotic changes after BMS implantation.
Journal Article
Prognostic value of tissue-tracking mitral annular displacement by speckle-tracking echocardiography in asymptomatic aortic stenosis patients with preserved left ventricular ejection fraction
2021
BackgroundTissue-tracking mitral annular displacement (TMAD) by speckle-tracking echocardiography provides rapid and simple assessment of left ventricular (LV) longitudinal deformation. The purpose of this study was to evaluate the value of TMAD for the assessment of LV longitudinal deformation in patients with severe AS and preserved LV ejection fraction (LVEF).MethodsWe studied 44 patients with severe AS preserved and LVEF in whom TMAD was assessed. Using TMAD analysis software, the base-to-apex displacement of automatically defined mid-point of mitral annular line in four-chamber view was quickly assessed, and the percentage of its displacement to LV length at end-diastole (%TMAD) was calculated. We investigated the association between %TMAD and the cardiac events including appearance of symptom (dyspnea on exertion and hospitalization due to heart failure), decreased LVEF (< 50%), and cardiac death.ResultsDuring follow-up, the cardiac events developed in 16 (36%) of 44 patients. %TMAD was significantly impaired in patients with the cardiac events compared with those without the cardiac events (9.6 ± 1.9 vs 12.1 ± 2.6, p = 0.002). The cardiac events were predicted by %TMAD (HR 0.68, 95% CI 0.54–0.85; p = 0.0012).ConclusionsThe present study suggests that TMAD easily and rapidly estimated by speckle-tracking echocardiography may be used as a simple method to predict occurrence of the cardiac events in asymptomatic severe AS patients with preserved LVEF.
Journal Article
Comparison of clinical outcomes following percutaneous coronary intervention versus optimal medical therapy based on gray-zone fractional flow reserve in stable angina patients with intermediate coronary artery stenosis (COMFORTABLE prospective study): Study protocol for a multicenter randomized controlled trial
by
Kitabata, Hironori
,
Kimura, Keizo
,
Gohda, Masahiro
in
Analysis
,
Angina pectoris
,
Angina, Stable - diagnostic imaging
2019
Background
Even in the current drug-eluting stent era, revascularization for coronary stenosis with fractional flow reserve (FFR) between 0.75 and 0.80, the so-called “gray zone,” is a matter of debate. Previous studies have reported conflicting results regarding outcomes of revascularization versus deferral for coronary stenosis when FFR values are in the gray zone, but these studies have had differing designs and populations. We therefore will investigate whether medical therapy plus percutaneous coronary intervention (PCI) is superior to medical therapy alone in reducing major cardiovascular events in patients presenting with coronary stenosis with gray zone FFR values.
Methods/design
This is a prospective, multicenter, open-label, parallel group, randomized, controlled, superiority study. A total of 410 eligible participants will be recruited and randomized to either the medical therapy plus PCI group or the medical therapy alone group. The primary endpoint is 1-year major adverse cardiac events (MACEs), defined as a combined endpoint of all-cause death, nonfatal myocardial infarction (MI), or unplanned target vessel revascularization (TVR). Secondary endpoints include MACE at 2 and 5 years. Moreover, each individual component of the primary endpoint, cardiovascular death, target vessel-related and non-target vessel-related MI, all MI, clinically driven TVR or non-TVR, all revascularization, stent thrombosis, and angina symptom status will be evaluated at 1, 2, and 5 years.
Discussion
This is the first prospective, multicenter, randomized, controlled study to investigate the superiority of medical therapy plus PCI over medical therapy by itself in reducing major cardiovascular events in patients presenting with coronary stenosis with “gray zone” FFR values. The results will help interventional cardiologists in making revascularization decisions regarding coronary stenosis with gray zone FFR values.
Trial registration
University Hospital Medical Information Network Clinical Trials Registry,
UMIN000031526
. Registered on 1 March 2018.
Journal Article