Koya Ozawa

Characteristic myocardial strain identified in hypertrophic cardiomyopathy subjects with preserved left ventricular ejection fraction using a novel multi-layer transthoracic echocardiography technique

PURPOSE In order to evaluate compensatory mechanisms in hypertrophic-cardiomyopathy (HCM) subjects with preserved left-ventricular (LV) ejection-fraction (EF), we measured myocardial percentage endocardial strain dependency, as represented by 2D LV global longitudinal (GLS) and circumferential-strain (GCS), using a novel, multi-layer, speckle-tracking transthoracic-echocardiography (TTE) technique. METHODS A total of 60 subjects (40 HCM with preserved LV EF (30 male; 62 ± 15 years, all LV EF>50%)) and 20 controls (10 male; 59 ± 10 years) underwent TTE (Vivid-E9). Quantitative strain-measurements of: endocardial, all and epicardial layers were performed at each-site. We defined percentage endocardial strain dependency as the ratio of endocardial strain to epicardial strain. RESULTS Absolute GLS values at all views in all, endocardial and epicardial myocardial layers were significantly smaller in HCM subjects than in controls (all P<0.001). There were no significant differences between both-groups in absolute GCS values in the endocardial layers, at the mitral valve and papillary muscle levels. Percentage endocardial GCS dependency at all levels were greater in HCM subjects than in controls (all P<0.01). In HCM subjects, percentage endocardial GCS dependency at the mitral valve and papillary muscle levels revealed significant, moderate, negative correlations with LV end-diastolic and systolic dimensions (correlation coefficients -0.505, -0.451 (mitral valve level) and -0.533, -0.591 (papillary muscle level), respectively). CONCLUSIONS In HCM subjects with preserved LV EF, 2D LV GLS was lower than in controls, but endocardial GCS was maintained in compensation for reduction in endocardial GLS; thus percentage endocardial GCS dependency may increase, and the larger the LV size, the smaller this compensatory effect.

Utility of three-dimensional global longitudinal strain of the right ventricle using transthoracic echocardiography for right ventricular systolic function in pulmonary hypertension

ventricle using transthoracic echocardiography for right ventricular systolic function in pulmonary hypertension Koya Ozawa , Nobusada Funabashi ⁎, Hiroyuki Takaoka , Nobuhiro Tanabe , Noriyuki Yanagawa , Koichiro Tatsumi , Yoshio Kobayashi a a Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba City, Chiba 260-8670, Japan b Department of Respirology, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba City, Chiba 260-8670, Japan

Specific organized substrates of ventricular fibrillation: Comparison of 320-slice CT heart images in non-ischemic ventricular fibrillation subjects with non-ischemic sustained and non-sustained ventricular tachycardia subjects

PURPOSE If specific organized substrates of ventricular-fibrillation (VF) are identified, they may provide important-information for prevention of sudden-cardiac-death. To identify specific organized substrates of VF, we compared 320-slice CT heart images in non-ischemic VF subjects with non-ischemic sustained and non-sustained ventricular-tachycardia (VT) subjects. MATERIALS AND METHODS Retrospective analysis of a total of 103 subjects who had VF (17 subjects; age, 59 ± 16 years), sustained VT (20 subjects; 62 ± 19 years), or non-sustained VT (66 subjects; 60 ± 15 years) underwent 320-slice CT (Aquilion one). RESULTS After excluding 26 ischemic subjects with >50% stenosis in any coronary arteries on CT, myocardial infarction, or coronary vasospastic angina, a total of 77 non-ischemic subjects (12 VF subjects; age, 58 ± 18 years), (13 sustained VT subjects; 55 ± 20 years) or (52 non-sustained VT subjects; 58 ± 15 years) were analyzed. On CT, myocardial abnormal-late-enhancement was significantly more frequent in the VF group (75%, all myocardial abnormal-late-enhancement in left-ventricle) than in the sustained VT group (31%) and the non-sustained VT group (35%) (both P<0.01). Myocardial fatty change was significantly more frequent in the sustained VT group (54%) than in the VF group (17%) and the non-sustained VT group (12%) (both P<0.01). Final diagnoses of the non-ischemic VF and sustained groups included four subjects in each case with normal cardiac structure on transthoracic echocardiogram; the former included two subjects who had abnormal-late-enhancement on CT without specific ECG findings. CONCLUSIONS Myocardial abnormal-late-enhancement and fatty change on CT may be substrates of VF or sustained VT in non-ischemic subjects. 320-slice CT can evaluate both coronary arteries and myocardium.

Adaptive-Iterative-Dose-Reduction 3D with multisector-reconstruction method in 320-slice CT may maintain accurate-measurement of the Agatston-calcium-score of severe-calcification even at higher pulsating-beats and low tube-current in vitro

320-slice CT may maintain accurate-measurement of the Agatston-calcium-score of severe-calcification even at higher pulsating-beats and low tube-current in vitro Nobusada Funabashi ⁎, Ryosuke Irie , Miki Aiba , Ryo Morimoto , Toru Kabashima , Shota Fujii , Masae Uehara , Koya Ozawa , Hiroyuki Takaoka , Yoshio Kobayashi a a Department of Cardiovascular Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba City, Chiba 260-8670, Japan b Radiological Department, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba City, Chiba 260-8670, Japan

A two center 320 slice CT study for evaluating coronary arteries in subjects with chronic atrial fibrillation: A comparison of prospective and retrospective ECG-gating acquisition

PURPOSE To compare diagnostic-accuracy of prospective and retrospective-ECG-gated acquisition in 320-slice-CT for detecting coronary-artery stenosis in subjects with chronic-atrial-fibrillation (CAF) in a two-center study. MATERIALS AND METHODS 53 CAF subjects who underwent 320-slice-CT, and invasive-coronary-angiogram (ICA) within 6-months (43 male; 69 ± 9 years; CHADS2 score 2.2 ± 1.3; CHA2DS2-VASc score 3.5 ± 1.6) in the two institutes were analyzed. In Institute-1, prospective-ECG-gated acquisition was routinely performed (N=33). In Institute-2, retrospective-ECG-gated acquisition was routinely performed (N=20). CT and ICA data were transferred to the analysis center and were analyzed by cardiologists blinded to the clinical-data. RESULTS Prevalence of >50 and >75% on ICA was 79 and 61% in Institute-1, and 30 and 15% in Institute-2, respectively. In a patient-by-patient analysis, Institute-2 had higher negative-predictive-value (NPV) and accuracy of >75% stenosis on CT in predicting >75% stenosis on ICA. In a vessel-by-vessel analysis, there were no significant-differences of sensitivity, specificity, positive-predictive-value (PPV) and NPV of >50% stenosis on CT in predicting >50% stenosis on ICA between both institutes. But sensitivity, specificity, and NPV of >75% stenosis on CT in predicting >75% stenosis on ICA were significantly higher in Institute-2 than in Institute-1. This is mainly because of more severe coronary-artery disease including calcification in Institute-1; there might also have been an influence of differences in scanning and reconstruction methods. CONCLUSIONS 320-slice-CT shows relatively high diagnostic-accuracy for the detection of significant coronary-artery stenosis compared with ICA even in CAF subjects, in a two-center analysis. Retrospective-ECG-gated acquisition in 320-slice-CT shows significantly higher diagnostic-accuracy than prospective-ECG-gated acquisition for detection of >75% coronary-artery stenosis.

The CHADS2 score is a useful predictor of coronary arteriosclerosis on 320 slice CT and may correlate with prognosis in subjects with atrial fibrillation

PURPOSE In evaluating coronary arteries by 64-256 slice CT, atrial fibrillation (AF) is usually an exclusion criterion. We used CHADS2 score to predict coronary arteriosclerosis estimated by 320-slice CT and prognosis in AF subjects. METHODS A total of 183 consecutive subjects (148 male; 64.1 ± 11.1 years, 97 hypertension, 60 hyperlipidemia, 21 diabetes mellitus, 76 smoking habits, body mass index 23.4 ± 3.5) who were diagnosed previously as chronic (N=104) or paroxysmal AF (N=79), and who underwent electrocardiogram-gated 320-slice CT were enrolled. The composite end point of cardiac death or sudden death was assessed. RESULTS A total of 183 AF subjects were divided into 3 groups: CHADS2 scores of 0 (N=53), 1 (N=57) and ≥2 (N=73). Frequency of the presence of calcified plaque, non-calcified plaque, mixed plaque, any plaque, and >50% stenosis and Agatston calcium score was significantly lower in CHADS2 score 0 group compared with score 1 or score ≥ 2 groups. In logistic-regression models for prediction of calcified plaque, or any plaque on CT, the odds ratios of CHADS2 score ≥ 2 group to CHADS2 score 0 or 1 group were 2.03 and 2.12, respectively (both P<0.05). During a median of 19.2 months, the composite-event-rate was significantly higher in subjects with CHADS2 score ≥ 2 than those with CHADS2 score 0 (P=0.049) in Kaplan-Meier survival analysis. CONCLUSIONS The CHADS2 score is a useful predictor of coronary arteriosclerosis on CT and may correlate with prognosis in AF subjects. Subjects with high CHADS2 score should be examined for coronary arteriosclerosis in addition to cerebral infarction.

Resting multilayer 2D speckle-tracking transthoracic echocardiography for the detection of clinically stable myocardial ischemic segments confirmed by invasive fractional flow reserve. Part 1: Vessel-by-vessel analysis.

PURPOSE To detect stable ischemic left ventricular (LV)-segments confirmed via invasive fractional flow reserve (FFR) by quantitative longitudinal-strain (LS) determined using resting multilayer TTE. METHODS A retrospective analysis of 39 stable patients (32 males; 65.8±11.9years) with 46 coronary arteries with ≥50% stenosis confirmed by invasive coronary angiography who underwent invasive FFR measurement and TTE (Vivid E9, GE). On TTE, regional LS (absolute values) were calculated in whole, endocardial, and epicardial layers perfused by stenotic coronary arteries. RESULTS Of the 46 vessels, FFR values of <0.75, ≥0.75, ≤0.80 and >0.80 were observed in 17, 29, 27 and 19 vessels, respectively. In a vessel-by-vessel analysis, the whole-layer and endocardial LS were significantly smaller in LV-segments perfused by vessels with an FFR<0.75 than in those with an FFR≥0.75, but epicardial LS was not. In ROC curves, the best cutoff values of whole-layer, endocardial and epicardial LS were, respectively, 14.0% (sensitivity, 94%; specificity 38%; area under the curve, 0.685), 10.0% (47%; 86%; 0.664) and 14.0% (100%; 24%; 0.640) to detect LV-segments with an FFR<0.75; and 14.0% (82%; 37%; 0.561), 10.0% (33%; 84%; 0.573), and 14.0% (89%; 21%; 0.538) to detect LV-segments with an FFR≤0.80. CONCLUSION For stable subjects with coronary arteries with ≥50% stenosis, the regional whole-layer and endocardial LS were significantly smaller in LV-segments perfused by vessels with an FFR<0.75 than in those with an FFR≥0.75, but epicardial LS was not; and that the whole-layer and endocardial LS had a modest diagnostic efficiency in identifying LV-segments perfused by vessels with an FFR<0.75.

CHA2DS2-VASc score is a useful-predictor of not prognosis but coronary-arteriosclerosis in chronic atrial-fibrillation compared with CHADS2 score: A two-center study of 320-slice CT, part 2

BACKGROUND The aim of this study is to predict the risk of coronary-arteriosclerosis and prognosis in subjects with chronic-atrial-fibrillation (CAF) using the CHADS2 and CHA2DS2-VASc scores by 320-slice-CT and invasive-coronary-angiography (ICA) in a two-center-study. METHODS 53 CAF subjects who underwent 320-slice-CT and ICA within 6-months (43 male; 69 ± 9 years; CHADS2 score 2.2 ± 1.3; CHA2DS2-VASc score 3.5 ± 1.6) in the two-institutes were analyzed. CT and ICA data were transferred to the analysis-center and were analyzed by cardiologists. RESULTS Agatston-calcium-score and frequencies of the presence of various-kinds of plaques and >50% and >75% coronary artery stenosis were significantly higher in the subjects with CHA2DS2-VASc score ≥ 3 compared with those with score <3. However there were no-significant differences in the Agatston-calcium-score and frequencies of the presence of various-kinds of plaques and >50% and >75% coronary artery stenosis evaluated by 320-slice CT between the subjects with CHADS2 score ≥ 2 and <2. Frequency of >50% coronary artery stenosis by ICA was significantly higher in the subjects with CHA2DS2-VASc score ≥ 3 compared with those with score <3. However, there were no-significant differences in the frequencies of >50% and >75% coronary artery stenosis by ICA between the subjects with CHADS2 score ≥ 2 and <2. During a mean of 15.9 months, composite rate of cardiac death and heart failure did not differ between subjects with CHADS2 score ≥ 2 and score <2 and between subjects with CHA2DS2-VASc score ≥ 3 and score <3. CONCLUSIONS The CHA2DS2-VASc score is a useful predictor of not prognosis but coronary-arteriosclerosis in subjects with CAF compared with CHADS2 score in this two-center-study.

Consistencies of 3D TTE global longitudinal strain of both ventricles between assessors were worse for 2D, but better for 3D ventricular EF

PURPOSE We evaluated the consistency of different-assessors in estimating three-dimensional (3D) global-longitudinal-strain (GLS) of left (LV) and right ventricle (RV) using transthoracic-echocardiography (TTE) for LV and RV systolic-function. We compared results from two-independent-specialists using this-approach for 3D LV and RV parameters in a population with 74% hypertrophic-cardiomyopathy (HCM) patients. METHODS 58 patients (43 HCM (32 male; 62 ± 15 years) and 15 controls (5 male; 53 ± 22 years)) underwent TTE (Vivid-E9) to measure 2D and 3D GLS of the LV and RV by two-independent-specialists. RESULTS Consistencies of estimates of 3D LV end-diastolic volume (EDV), end-systolic volume (ESV), and ejection-fraction (EF) between the two-assessors were 0.872 (3D LVEDV, P<0.001), 0.797 (3D LVESV, P<0.001), and 0.215 (3D LVEF, P=0.105). Consistencies of 2D and 3D LV GLS between two-assessors were 0.900 (2D LVGLS, P<0.001) and 0.874 (3D LVGLS, P<0.001). Consistencies of estimates of 3D RVEDV, RVESV, and RVEF between two assessors were 0.781 (3D RVEDV, P<0.001), 0.755 (3D RVESV, P<0.001), and 0.26 (3D RVEF, P=0.049). Consistencies of 2D and 3D GLS of whole RV and those of RV free wall only between two-assessors were 0.886 (2D GLS of whole RV, P<0.001), 0.687 (3D GLS of whole RV, P<0.001), 0.707 (2D GLS of RV free wall, P<0.001), and 0.630 (3D GLS of RV free wall, P<0.001). CONCLUSIONS Consistencies of independent-estimates of 3D GLS of the LV and RV using TTE between two-assessors were worse than for 2D GLS of the LV and RV, but better than for 3D LVEF and RVEF in a population with 74% HCM patients.

Inter- and intraobserver consistency in LV myocardial strain measurement using a novel multi-layer technique in patients with severe aortic stenosis and preserved LV ejection fraction.

BACKGROUND A new transthoracic echocardiography (TTE) technique allows multi-layer measurement of left ventricular (LV), endocardial, epicardial, and whole layer myocardial strain. We evaluated interobserver and intraobserver TTE reproducibility for 2D LV global longitudinal (GLS) and circumferential strain (GCS) estimates using data from severe aortic stenosis (AS) subjects with preserved LV ejection fraction (EF). METHODS Twenty severe AS subjects (11 male; mean age, 75±7years; LV EF >50%) underwent TTE (Vivid E9, GE Healthcare). Quantitative strain measurements of whole, endocardial, and epicardial layers were performed. GLS was defined as all 17 averaged LV segments, according to the American Heart Association classification. GCS was measured at the levels of the mitral valve, papillary muscle, and apex. RESULTS Interobserver correlation coefficients in whole, endocardial, and epicardial layers for GLS estimates were 0.81, 0.83, and 0.80, respectively, whereas those for GCS estimates were 0.38, 0.56, and 0.19, respectively, for the mitral valve, 0.44, 0.54, and 0.36, respectively, for the papillary muscle, and 0.55, 0.29, and 0.59, respectively, for the apex. Intraobserver correlation coefficients in whole, endocardial, and epicardial layers for GLS estimates were 0.97, 0.97, and 0.94, respectively, whereas those for GCS estimates were 0.86, 0.81, and 0.50 , respectively, for the mitral valve, 0.56, 0.72, and 0.28, respectively, for the papillary muscle, and 0.70, 0.69, and 0.62, respectively, for the apex. CONCLUSION In severe AS subjects with preserved LVEF, inter- and intra-observer TTE reproducibility in whole, endocardial, and epicardial layers were more consistent for 2D LV GLS than for 2D LVGCS.