Publications (8)16.63 Total impact
-
Article: Detection of restenosis after percutaneous coronary intervention in three major coronary arteries by transthoracic Doppler echocardiography.
[show abstract] [hide abstract]
ABSTRACT: The aim of this study was to evaluate the diagnostic potential of coronary flow velocity reserve (CFR) measurement by transthoracic Doppler echocardiography (TTDE) to detect restenosis in the 3 major coronary arteries: the left anterior descending coronary artery, right coronary artery, and left circumflex coronary artery. The lesions of 175 patients who were scheduled for follow-up coronary angiography and TTDE 6 months after undergoing stents implantation were studied. CFR was assessed by TTDE in the targeted arteries into which stents had been implanted. Coronary stents were implanted in a total of 238 angiographic lesions in 175 patients. Doppler recordings of coronary flow in the 3 major arterial lesions were obtained in 211 of the 238 angiographic lesions (89% feasibility). CFR was significantly lower in lesions with restenosis than those without restenosis (1.70 +/- 0.32 vs 2.65 +/- 0.66, P < .01). A CFR value < 2.0 was 89% sensitive and 91% specific for detecting restenosis in the 3 major coronary arteries. Sensitivity and specificity were 86% and 91%, respectively, in the left anterior descending coronary artery (95% feasibility); 92% and 92%, respectively, in the right coronary artery (85% feasibility); and 91% and 92%, respectively, in the left circumflex coronary artery (81% feasibility). CFR assessment by TTDE is an accurate method for monitoring restenosis, not only in the left anterior descending but also in the right and left circumflex coronary arteries in patients previously subjected to percutaneous coronary intervention.Journal of the American Society of Echocardiography: official publication of the American Society of Echocardiography 05/2010; 23(5):553-9. · 2.98 Impact Factor -
Article: Usefulness of a combination of systolic function by left ventricular ejection fraction and diastolic function by E/E' to predict prognosis in patients with heart failure.
[show abstract] [hide abstract]
ABSTRACT: Left ventricular (LV) ejection fraction (EF) was known as a conventional predictor of heart failure (HF). However, early transmitral flow velocity (E)/early diastolic velocity of mitral annulus (E') correlated well with LV end-diastolic pressure, and E/E' ratio >15 was an excellent predictor of adverse outcomes in patients with HF. This study was designed to determine the prognostic value of a new combined index, E/E' ratio and LVEF, in patients with HF. One hundred twenty-six consecutive patients hospitalized with HF underwent comprehensive echocardiographic-Doppler study when ready for discharge. Patients were divided into the 4 groups of group I (LVEF >40% and E/E' ratio <15), group II (EF >40% and E/E' ratio >or=15), group III (EF <or=40% and E/E' ratio <15), and group IV (EF <or=40% and E/E' ratio >or=15). The ability of this index to determine the primary end point (rehospitalization for HF or cardiac death) was assessed. Patients with significant valvular disease were excluded. Of 126 patients, 110 met the inclusion criteria. Follow-up was complete for 108 of 110 patients at 351 +/- 252 days after discharge. There were 27, 30, 21, and 30 patients in groups I, II, III, and IV, respectively. There were 52 patients with the primary end point. On univariate analysis, E/E' ratio, group IV, E', and age were significant predictors. In multivariable analysis, the most powerful independent prognostic indicator of events was group IV (hazard ratio 12.6, 95% confidence interval 2.2 to 74.2, p = 0.005). In conclusion, a new index, a combination of LVEF and E/E' ratio, allowed the identification of patients at higher risk of readmission and cardiac death in patients with HF.The American journal of cardiology 05/2009; 103(9):1275-9. · 3.58 Impact Factor -
Article: Clinical use of Doppler echocardiography and Doppler tissue imaging in the estimation of myocardial ischemia during dobutamine stress echocardiography.
[show abstract] [hide abstract]
ABSTRACT: The ratio of mitral inflow early diastolic velocity (E) to annulus velocity (E') might be critical for the assessment of an abnormal filling pressure for patients with myocardial ischemia. We sought to determine whether a quantitative estimation of E/E' provides more reliable information for detecting coronary artery disease during dobutamine stress echocardiography. A total of 82 patients suggested to have angina pectoris underwent Doppler studies during dobutamine stress echocardiography. The value of E and E' were measured at baseline and peak dose of dobutamine stress. The value of E/E' during stress over that at rest was defined as the E/E' index. Patients who had significant stenosis by coronary angiogram were classified as being in group A (n = 45) and those with no coronary artery disease were classified as being in group B (n = 37). Dobutamine infusion led to a significant increase of E/E' in group A, whereas no changes were found with group B. Likewise, larger E/E' index was also observed for patients with multivessel disease. The value of E/E' index increased proportionally with the number of stenotic vessels, implying a direct correlation of the E/E' value to the extent of myocardial ischemia. E/E' offers a quantitative estimation of myocardial ischemia during dobutamine stress echocardiography, thereby, providing a reliable and accurate method for the evaluation of coronary artery disease.Journal of the American Society of Echocardiography: official publication of the American Society of Echocardiography 05/2008; 21(4):331-6. · 2.98 Impact Factor -
Article: Method analysis for optimal continuous imaging using intravascular optical coherence tomography.
[show abstract] [hide abstract]
ABSTRACT: Optical coherence tomography(OCT)is a high-resolution imaging method that can clearly visualize vessels through the displacement of blood with flushing agents. Continuous imaging methods have not been established. This study investigated optimal methods for continuous OCT imaging. Thirty-four arteries with stent implantation (24 peripheral and 10 coronary arteries)in 14 pigs were examined using OCT with a motorized pullback device. Two imaging methods (flush alone by liquid substance and flush with occlusion) were compared. Adequate image acquisition was defined as the entire circumferential intimal layer being detectable within continuous segments. To investigate factors that could influence image quality, stented regions were divided into 4-5 mm segments. The flush with occlusion method provided better OCT images compared to flush alone (flush with occlusion: 60.9%, flush alone: 8.7%, p = 0.0002). Using the flush with occlusion method, the rate of adequate image acquisition was 64.4% and visualization of > 75% intimal circumference was 83.5%. Intravascular ultrasound could detect all stented regions. Segmental analyses found more adequate images were detected in smaller vessels (adequate segment: 3.8 +/- 0.4 mm, inadequate segment: 4.2 +/- 0.8 mm, p < 0.0001) or with centered image wire position (adequate segment: center 35%, inadequate segment: center 14%, p = 0.003). In addition, side branches did not affect image quality. To acquire continuous OCT images, the flush with occlusion method was more effective compared to flush alone. Moreover, image quality is affected by vessel size and imaging wire position. These results suggest that optimized OCT imaging can provide continuous vessel detection.Journal of Cardiology 04/2006; 47(3):133-41. · 1.28 Impact Factor -
Article: Impact of HMG-CoA reductase inhibitors for non-treated coronary segments.
[show abstract] [hide abstract]
ABSTRACT: HMG-CoA reductase inhibitors (statin) have been reported to decrease coronary artery events in several angiographic studies. However, the mechanism by which statin achieve this is still unclear. The purpose of this study was to identify the effect of statin on coronary plaque using serial intravascular ultrasound analysis. In this study, 48 patients with 48 lesions were divided into the prescribed group (statin group, n = 22) or the non-prescribed group (control group, n = 26) after successful coronary artery stenting. IVUS images were obtained at consecutive 5 mm segments, 5 mm from the proximal stent edge, immediately after stenting and at 6 months follow up. External elastic membrane volume (EEMV), lumen volume (LV) and plaque volume (PV) were measured using Simpson's method. The control group revealed no significant serial change in EEMV, PV, and LV during 6 months. On the other hand, the statin group revealed significant reductions of PV (35.5 +/- 12.7 mm3 vs 30.9 +/- 15.6 mm3, p = 0.001), resulting in increase of LV (47.7 +/- 19.8 mm3 vs 52.5 +/- 22.2 mm3, p = 0.003) without EEMV change (82.8 +/- 21.8 mm3 vs 83.9 +/- 25.7 mm3, p = NS). Although percent EEMV and percent LV changes showed no differences between the two groups, a larger percent PV change was observed in the statin group compared to the control group (control; 5.8 +/- 20.3% vs statin; -20.4 +/- 21.8%, p = 0.02). The results of this study suggest that statin administration for 6 months reduces coronary plaque without positive vessel remodeling.Osaka city medical journal 01/2005; 50(2):61-8. -
Article: The impact of IVUS guided bare metal stent implantation for non-small vessel.
[show abstract] [hide abstract]
ABSTRACT: Previous studies have shown larger target vessel or greater stent area contribute to reduced restenosis rate. Thus, intravascular ultrasound (IVUS)-guided bare metal stent (BMS) implantation for selected lesions might achieve drug-eluting stent-like outcomes. The aim was to examine the long-term outcomes of BMS using IVUS-guided optimization. Consecutive 103 coronary artery lesions suitable for IVUS were enrolled. Using IVUS, final stent balloon size selected was 90 percent of media-to-media diameter at the lesion or distal reference. The balloon size was listed as follows: group A (3.0-3.5 mm, n = 15), group B (3.5-3.75 mm, n = 64), and group C (3.75-4.5 mm, n = 24). At post-intervention, average stent area increased by the balloon size (A: 7.2 +/- 1.4 mm2, B: 8.9 +/- 1.5 mm2, and C: 12.1 +/- 2.0 mm2, respectively p < 0.001). At 6 month follow up, the average lumen area increased by balloon size (A: 4.1 +/- 1.7 mm2, B: 5.7 +/- 1.2 mm2, and C: 8.1 +/- 2.0 mm2, respectively p < 0.001). Accordingly, group B and C revealed lower restenosis, compared to group A (A: 46.7%, B: 10.9%, C: 8.3%, A vs B: p = 0.001; C vs A: p = 0.015). Moreover, target lesion revascularization was less in group B and C than group A (A 26.6%, B 3.1%, C 0%, A vs B: p = 0.011; C vs A: p = 0.017). For non-small vessels, IVUS-guided BMS implantation showed less restenosis and target lesion revascularization compared to small vessels, mainly due to larger initial gain. These study results suggest that IVUS-guided optimal BMS implantation for selected lesions might result in favorable long-term outcomes similar to those seen using drug-eluting stents. For a decade, coronary stenting has become a standard therapy for coronary artery disease due to favorable long-term outcomes and simple treatment procedure. Furthermore, for the last two years, drug-eluting stents (DES), releasing antiproliferative agents from bare metal backbone, revealed the restenosis rates less than half of those seen using conventional bare metal stents (BMS). While target lesions especially suitable for DES continue to be identified, earlier BMS studies showed that larger target vessel or greater stent area contributed to less restenosis. Thus, optimal IVUS-guided BMS implantation for selected lesions might achieve DES-like long-term outcomes. This study was designed to examine the long-term outcomes of BMS with intravascular ultrasound (IVUS)-guided optimization, using coronary angiography and IVUS data.Osaka city medical journal 12/2004; 50(2):79-86. -
Article: Head-to-head comparison of fundamental, tissue harmonic and contrast harmonic imaging with or without an air-filled contrast agent, levovist, for endocardial border delineation in patients with poor quality images.
[show abstract] [hide abstract]
ABSTRACT: Recent developments in tissue harmonic imaging and intravenous contrast agents have enhanced left ventricular endocardial border delineation (EBD). In a total of 48 patients with poor quality images, apical 4- and 2-chamber views were obtained with fundamental, tissue harmonic and contrast harmonic imaging with or without intravenous Levovist, an air-filled contrast agent. The left ventricle (LV) was divided into 12 segments, and the EBD of each segment was scored: (1) not visible, (2) barely visible, (3) well delineated. The EBD index (EBDI), defined as the sum of the endocardial scores divided by 12 was obtained for each patient. Of a total of 576 LV segments, 231 were scored as 1 by fundamental imaging and that number decreased to 125 segments by tissue harmonic imaging and 116 segments by fundamental imaging with Levovist. The number of segments scored as 1 decreased to 38 segments by tissue harmonic imaging with Levovist, and to 29 segments by contrast harmonic imaging with Levovist. The EBDI by fundamental imaging was 1.85+/-0.29, which improved significantly with the addition of Levovist (2.10+/-0.36, p<0.001) and was nearly identical to that by tissue harmonic imaging (2.15+/-0.32, p=NS). Tissue and contrast harmonic imaging with Levovist further enhanced the EBDI (2.43+/-0.26, 2.51+/-0.27, respectively). Levovist enhances EBD, even in the fundamental mode, to the level obtained with tissue harmonic imaging. Tissue harmonic and contrast harmonic imaging are the best modalities for enhancing EBD after Levovist injection.Circulation Journal 05/2002; 66(5):494-8. · 3.77 Impact Factor -
Article: Short- and long-term outcomes of compromised side branches after Multi-Link stent implantation.
[show abstract] [hide abstract]
ABSTRACT: The Multi-Link stent is superior to other stents in terms of low rates of restenosis and target vessel revascularization. However, few data exist regarding short- and long-term outcomes for side branches after stenting. We evaluated short and long clinical outcomes and angiographic predictors of side-branch occlusion after the deployment of 137 Multi-Link stents. Thirty-four (25%) of the 137 side branches occluded immediately after stenting. We attempted reangioplasty for the side branches and our success rate was 85%. The incidence of side branches with intrinsic ostial disease was more than 50% before stenting and origination from the stented midsegment was a powerful angiographic predictor of side-branch occlusion. Side-branch patency is well maintained long-term. The incidence of restenosis within and near the stented segment of the parent vessel was 19%, and the incidence of target vessel revascularization was 15%. We recommend the use of Multi-Link stents regardless of the presence of side branches in the vicinity of the stenosis.Heart and Vessels 04/2002; 16(3):86-90. · 2.05 Impact Factor
Top co-authors
Top Journals
Institutions
-
2002–2005
-
Osaka City University
- Graduate School of Medicine
Ōsaka-shi, Osaka-fu, Japan
-
