Kumiko Hirata

BACKGROUND: Thrombotic microangiopathy (TMA) syndromes include thrombotic thrombocytopenic purpura (TTP) and haemolytic uremic syndrome, and contribute to myocardial infarction and multiple organ failure. Although coronary microvascular dysfunction (CMD) is the key for understanding the pathophysiology of cardiac involvement in TMA, there is limited knowledge on the recovery from CMD in patients with TMA. CASE SUMMARY: An 80-year-old woman was brought to the emergency department due to worsening back pain, dyspnoea on exertion, jaundice, and fever. Although she had typical TTP symptoms and elevated cardiac troponin level, ADAMTS13 activity was preserved (34%), leading to the diagnosis of TMA with myocardial infarction. She underwent plasma exchange and was administered aspirin and prednisolone. Magnetic resonance imaging revealed iliopsoas abscess, which is a possible aetiologic factor of sepsis-related TTP. She had impaired coronary flow reserve (CFR) with angiographically non-obstructive epicardial coronary arteries. Improved CFR was observed on follow-up, suggesting existence of transient CMD caused by TMA. After treatment of the iliopsoas abscess with antibiotics for 3 months, she was discharged without any adverse complications. DISCUSSION: Coronary microvascular dysfunction is an underlying mechanism of myocardial infarction, with or without epicardial obstructive coronary artery stenosis. TMA is characterized by pathological lesions caused by endothelial cell damage in small terminal arteries and capillaries, with complete or partial occlusion caused by platelet and hyaline thrombi. CMD and its recovery are keys for understanding the natural history of cardiac involvement in TMA. In vivo evaluations of CMD can provide mechanistic insights into the cardiac involvement in TMA.

BACKGROUND: This study aimed to investigate the association between the extent and severity of coronary atherosclerosis, epicardial adipose tissue (EAT) accumulation, and left ventricular (LV) global longitudinal strain (GLS) in patients with preserved LV ejection fraction (LVEF) and without LV regional wall motion abnormalities. METHODS: This study included 169 preserved LVEF patients without LV wall motion abnormalities who underwent coronary computed tomography (CT) angiography for the assessment of suspected coronary artery disease (CAD). The segment stenosis score (SSS) and segment involvement score (SIS) were calculated to evaluate CAD extent. The EAT volume was defined as CT attenuation values ranging from -250 to -30 HU within the pericardial sac. LVGLS was measured using echocardiography to assess subclinical LV dysfunction. RESULTS: All patients had preserved LVEF of ≥50%, and the mean LVGLS was -18.7% (-20.5% to -16.9%). Mean SSS and SIS were 2.0 (0-5) and 4.0 (0-36), respectively, while mean EAT volume was 116.1 mL (22.9-282.5 mL). Multivariate analysis using linear regression model demonstrated that LVEF (β, -17.0; 95% CI, -20.9 - -13.1), LV mass index (β, 0.03; 95% CI, 0.01-0.06), and EAT volume (β, 0.010; 95% CI, 0.0020-0.0195) were independently associated with LVGLS; however, obstructive CAD was not. The multivariate models demonstrated that SSS (Î, 0.12; 95% CI, 0.05-0.18) and SIS (Î, 0.27; 95% CI, 0.10-0.44) were correlated with deterioration of LVGLS, independent of other parameters. CONCLUSION: This study demonstrates that EAT volume and CAD extent are associated with the deterioration of LVGLS in this population.

BACKGROUND: Wide-volume scanning with 320-row multidetector computed tomography coronary angiography (CTCA-WVS) enables the assessment of the aortic arch plaque (AAP) morphology and coronary arteries without requiring additional contrast volume. This study aimed to investigate the prevalence of AAPs and their association with coronary artery disease (CAD) and major adverse cardiovascular events (MACEs) in patients who underwent CTCA-WVS. METHODS: This study included 204 patients without known CAD (mean age, 65 years; 53% men) who underwent CTCA-WVS. We evaluated the presence of aortic plaques in the ascending aorta, aortic arch, and thoracic descending aorta using CTCA-WVS. Large aortic plaques were defined as plaques of at least 4 mm in thickness. A complex aortic plaque was defined as a plaque with ulceration or protrusion. MACEs were defined as composite events of cardiovascular (CV) death, nonfatal myocardial infarction, and ischemic stroke. RESULTS: AAPs and large/complex AAPs were identified in 51% ( n = 105) and 18% ( n = 36) of the study patients, respectively. The prevalence of AAPs with large/complex morphology increased with CAD severity (2.1% in no CAD, 12% in nonobstructive CAD, and 39% in obstructive CAD). The univariate Cox hazard model demonstrated that the predictors associated with MACEs were diabetes, obstructive CAD, and large/complex AAPs. Independent factors associated with large/complex AAPs were male sex [odds ratio (OR), 2.90; P = 0.025], stroke history (OR, 3.48; P = 0.026), obstructive CAD (OR, 3.35; P = 0.011), and thoracic aortic calcification (OR, 1.77; P = 0.005). CONCLUSION: CTCA-WVS provides a comprehensive assessment of coronary atherosclerosis and thoracic aortic plaques in patients with CAD, which may improve the stratification of patients at risk for CV events.

AIMS: In patients with heart failure, over-activation of the cardiac sympathetic nerve (CSN) function is associated with severity of heart failure and worse outcome. The effects of MitraClip therapy on the CSN activity in patients with mitral regurgitation (MR) remained unknown. In this study, we evaluated the impact of the MitraClip therapy on CSN activity assessed by 123 I-metaiodobezylguanidine (MIBG) scintigraphy. METHODS AND RESULTS: We enrolled consecutive patients with moderate-to-severe (3+) or severe (4+) MR who were scheduled to undergo MitraClip procedure in this prospective observational study. MIBG scintigraphy was performed at baseline and 6 months after the MitraClip procedure to evaluate the heart-mediastinum ratio and washout rate (WR). Changes in these MIBG parameters were analysed. Of the 13 consecutive patients, 10 were successfully treated with MitraClip procedure and completed follow-up assessment. With regard to the MIBG parameters, changes in the early and delayed heart-mediastinum ratio from baseline to 6 months were not significant (2.16 ± 0.42 to 2.06 ± 0.34, P = 0.38 and 1.87 ± 0.39 to 1.83 ± 0.39, P = 0.43, respectively), whereas WR was significantly decreased (38.6 ± 3.9% to 32.6 ± 3.94%, P = 0.002). CONCLUSIONS: The CSN activity of the WR on MIBG imaging was improved 6 months after MitraClip therapy in patients with 3+ or 4+ MR.

BACKGROUND: Non-ischemic cardiomyopathy (NICM) is a heterogeneous disease, and its prognosis varies. Although late gadolinium enhancement (LGE)-cardiovascular magnetic resonance (CMR) demonstrates a linear pattern in the mid-wall of the septum or multiple LGE lesions in patients with NICM, the therapeutic response and prognosis of multiple LGE lesions have not been elucidated. This study aimed to investigate the frequency of left ventricular (LV) reverse remodeling (LVRR) and prognosis in patients with NICM who have multiple LGE lesions. METHODS: This single-center retrospective study included 101 consecutive patients with NICM who were divided into 3 groups according to LGE-CMR results: patients without LGE (no LGE group = 48 patients), patients with a typical mid-wall LGE pattern (n = 29 patients), and patients with multiple LGE lesions (n = 24 patients). LVRR was defined as an increase in LV ejection fraction (LVEF) ≥ 10 % and a final value of LVEF > 35 %, which was accompanied by a decrease in LV end-systolic volume ≥ 15 % at 12-month follow-up using echocardiography. The frequency of composite cardiac events, defined as sudden cardiac death (SCD), aborted SCD (non-fatal ventricular fibrillation, sustained ventricular tachycardia, or adequate implantable cardioverter-defibrillator therapies), and heart failure death or hospitalization for worsening heart failure, were summarized and compared between the groups. RESULTS: Among the 3 groups, the frequency of LVRR was significantly lower in the multiple lesions group than in the no LGE and mid-wall groups (no LGE vs. mid-wall vs. multiple lesions: 49 % vs. 52 % vs. 19 %, p = 0.03). There were 24 composite cardiac events among the patients: 2 in patients without LGE (hospitalization for worsening heart failure; 2), 7 in patients of the mid-wall group (SCD; 1, aborted SCD; 1 and hospitalization for worsening heart failure; 5), and 15 in patients of the multiple lesions group (SCD; 1, aborted SCD; 8 and hospitalization for worsening heart failure; 6). The multiple LGE lesions was an independent predictor of composite cardiac events (hazard ratio: 11.40 [95 % confidence intervals: 1.49-92.01], p = 0.020). CONCLUSIONS: Patients with multiple LGE lesions have a higher risk of cardiac events and poorer LVRR. The LGE pattern may be useful for an improved risk stratification in patients with NICM.

Under the coronavirus disease 2019 (COVID-19) pandemic, the Japanese Society of Echocardiography (JSE) has been working to protect medical staff involved in echocardiographic examinations and to prevent secondary infections caused by the examinations since mid-March 2020. This review aims to describe the footprint of the JSE's responses, focusing on the 3 months in which the initial outbreak of COVID-19 pandemic occurred in Japan. We summarized the six parts as follows: (1) the initial actions for COVID-19 of JSE, (2) JSE’s actions for infection control-associated echocardiographic examinations, (3) statements from the American Society of Echocardiography during the COVID-19 pandemic and their Japanese translation by JSE, (4) making videos for explaining the practice of echocardiography during the COVID-19 pandemic, (5) attempts with the JSE members’ opinions by the communication platform and surveys, and (6) efforts of final statement during the initial spread of COVID-19. We look forward that this review will help daily practices associated with echocardiography under the COVID-19 pandemic and in the future event of an unknown infectious disease pandemic.

In the original publication of the article, the text citations of the Figs. 4-1, 4-2 and 5 should be Figs. 4, 5 and 6.

BACKGROUND: There are limited data available regarding the use of diastolic deceleration time (DDT) of three major arteries measured by transthoracic echocardiography (TTE) for assessing coronary microvascular damage after acute myocardial infarction (AMI). Therefore, we aimed to compare the DDT of three major arteries using TTE with the transmural extent of infarction (TEI) and infarct size, which were classified using contrast-enhanced magnetic resonance imaging (CE-MRI), in patients with AMI. METHODS: The DDT of the culprit coronary artery was measured in 74 patients using TTE and CE-MRI 1 week after the onset of AMI. The TEI was graded based on the transmural extent of the hyper-enhanced tissue (grades 1-4). RESULTS: The assessable rate for the DDT was 95%; individual rates were 100% for the left anterior descending coronary artery, 90% for the left circumflex artery, and 93% for the right coronary artery. The DDT decreased gradually as the TEI grade progressed (P = .021). Infarct size was significantly correlated with the DDT (r = -0.51, P < .0001). Univariate analysis revealed that the left ventricular (LV) end-systolic volume, LV ejection fraction, and DDT were significantly associated with TEI grade 4. After adjustment via multiple logistic regression analysis, the DDT was independently remained. With a cutoff value of 950ms, as determined by the ROC curve, DDT could detect TEI grade 4 with 81.1% sensitivity and 80.1% specificity. CONCLUSION: The DDT of three major coronary arteries measured by TTE 1 week after the onset of AMI can assess the extent of myocardial damage, which is determined by CE-MRI.

There have been few studies with a large number of patients on the effect of left ventricular (LV) reverse remodeling and long-term outcomes after aortic valve replacement (AVR). This study aimed to investigate long-term outcomes and the prognostic impact of follow-up echocardiographic parameters after AVR. We evaluated 456 consecutive patients from a retrospective multicenter registry in Japan (J-PROVE-Retro) who underwent AVR for aortic valve diseases (predominantly aortic stenosis [AS]; 326 patients and aortic regurgitation [AR]; 130 patients). Preoperative and follow-up echocardiography at 1 year after AVR was evaluated. The primary outcome measure was a composite of cardiac death or hospitalization due to heart failure. The median follow-up period was 9.2 years in AS group and 9.7 years in AR group. The freedom rate from the primary outcome was 92% at 5 years and 79% at 10 years in AS, and 97% at 5 years, and 93% at 10 years in AR. LV end-diastolic and end-systolic diameters, and the LV mass index decreased and LV ejection fraction increased after AVR in both AS and AR, and LV mass index was normalized in more than half of the patients. In the Cox proportional hazard model, echocardiographic parameters at 1 year after AVR were more strongly related to long-term outcomes than preoperative echocardiographic parameters. In conclusion, echocardiographic parameters at 1 year after AVR are more important as predictors of long-term outcomes than preoperative parameters in both AS and AR. More attention should be paid on early postoperative remodeling for long-term follow-up of patients after AVR.

INTRODUCTION: Cardioprotective effects of erythropoietin (EPO) on infarcted myocardium in acute myocardial infarction (AMI) patients have been inconclusive. This study aimed to assess the effect of EPO administration on coronary microvascular dysfunction (CMD) and myocardial viability in anterior AMI. We also evaluated the serial changes in CMD and cardiac remodeling in these patients. METHODS: Patients with a successful percutaneous coronary intervention (PCI) for the first anterior AMI were randomly assigned to two groups (EPO and control groups), and given single-dose intravenous administration of recombinant human EPO (12,000 IU) or saline after PCI. Delayed-enhanced cardiac magnetic resonance imaging was performed at 1 week after AMI to assess the average of transmural extent of infarction and infarct size. Coronary flow velocity reserve (CFVR) of the left anterior descending coronary artery was measured by Doppler echocardiography at 1 week, 1 month, and 8 months after AMI. All patients underwent clinical follow-up for the assessment of cardiac remodeling. RESULTS: Sixty-one patients (EPO 32, control 29) were eligible for analysis. EPO group (2.4 ± 1.2) had a tendency of smaller transmural extent of infarction than that of control group (2.9 ± 1.1; p = 0.063). CFVR-8 months improved significantly in EPO group (2.9 ± 0.6) compared to control group (2.6 ± 0.5; p = 0.04). Left atrial (LA) volume - 8 months was significantly lower in EPO group (47 ± 11) than those of control group (65 ± 20; p = 0.004). CONCLUSIONS: A single medium dose of EPO could have a favorable effect on CMD and LA remodeling in the chronic phase of anterior AMI. TRIAL REGISTRATION: The institutional ethics committee of Wakayama Medical University, identifier, 1125.

OBJECTIVE: To examine the diagnostic ability of the deceleration time of early mitral annular velocity (e'DT) as determined by tissue Doppler velocity image, a method for assessing LV filling pressure. BACKGROUNDS: Estimation of LV filling pressure by Doppler echocardiography requires a combination of various parameters. Therefore, there remains a need for a simple index in LV filling pressure estimation. The e' is known to be reduced and delayed with increased LV filling pressure during development of heart failure. Thus, we hypothesized that e'DT would be shortened as LV filling pressure is increased. METHODS: Simultaneous LV end-diastolic pressure (LVEDP) measurement and Doppler echocardiography were performed in 94 patients who were admitted to our hospital for heart failure. Exclusion criteria were atrial fibrillation, mitral valve surgery, and acute coronary syndrome. RESULTS: The e'DT in 31 patients with LVEDP >16 mm Hg (68±13 ms) was significantly shorter than that in 63 patients with LVEDP ≤16 mm Hg (103±27 ms). Both e'DT and early transmitral flow velocity (E)/e' were significantly correlated with LVEDP. In 30 patients with 10-14 E/e', significance of correlation in e'DT was remained, while E/e' was not. The area under the ROC curve for prediction of LVEDP >16 mm Hg for e'DT was greater than that for E/e' (0.91 vs 0.74, P=.046). CONCLUSION: The e'DT is useful to assess LV filling pressure, especially in 10-14 E/e'. This simple tissue Doppler index may be a potential parameter for easily distinguishing between mild and severe heart failures.

OBJECTIVES: The aim of this study was to determine the best threshold of postintervention minimum stent area (MSA) assessed by optical coherence tomography (OCT) to predict long-term in-stent restenosis (ISR) for 2.5 mm-diameter everolimus-eluting stents (EES). BACKGROUND: Percutaneous coronary intervention (PCI) for small coronary arteries remains challenging. Stent underexpansion is a strong predictor of late ISR. METHODS: We performed a retrospective analysis of 69 lesions in 69 patients undergoing PCI with 2.5 mm-diameter stents using OCT for the assessment of postintervention MSA and subsequent 9-month angiographic follow-up. RESULTS: The rates of angiographic ISR and target lesion revascularization were 7.2% and 1.4%. The postintervention OCT-MSA of EES < 3.5 mm(2) for predicting ISR yielded a sensitivity of 80%, specificity of 71%, positive predictive value of 18%, and negative predictive value of 98%. There was a marginally significant trend between increasing MSA quartiles and decreasing ISR rate (P for trend = 0.07). CONCLUSIONS: Postintervention OCT-MSA of 3.5 mm(2) best predicted 9-month ISR following PCI with 2.5-mm-diameter EES. Further large, prospective, observational studies are warranted that validate this result. © 2015 Wiley Periodicals, Inc.

BACKGROUND: Complete heart block (CHB) caused by myocardial inflammation is a serious consequence of cardiac sarcoidosis (CS) that requires early diagnosis for effective anti-inflammatory treatment. OBJECTIVE: This study aimed to clarify the cardiac magnetic resonance imaging (MRI) and (18)F-fluoro-2-deoxyglucose positron emission tomography ((18)F-FDG PET) manifestations of newly diagnosed CS with CHB and to assess whether certain imaging features could predict responders to corticosteroid therapy. METHODS: Fifteen newly diagnosed CS patients with CHB and 17 without CHB were examined. We defined abnormal (18)F-FDG uptake on (18)F-FDG PET and increased T2-weighted signal on cardiac MRI as signs of myocardial inflammation and delayed enhancement (DE) on cardiac MRI as a sign of myocardial fibrosis. Ten CHB+ patients were then treated with corticosteroids. RESULTS: The CHB+ group showed higher (18)F-FDG uptake and increased T2-weighted signal in the interventricular septum, which involves the electrical pathway of atrioventricular conduction, than the CHB- group (P = .001 and P < .0001, respectively), whereas there was no group difference in DE (P = .232). Six corticosteroid-treated patients recovered from CHB; all had exhibited increased T2-weighted signal, (18)F-FDG uptake, and DE in the interventricular septum before therapy. In contrast, among the 4 patients without recovery, 2 showed no abnormal (18)F-FDG uptake and 3 had no increased T2-weighted signal in the interventricular septum, but all showed DE. The 2 patients without recovery with abnormal (18)F-FDG uptake showed wall thinning in the interventricular septum. CONCLUSION: Focal inflammation in the interventricular septum was associated with CHB and might predict recovery from CHB after corticosteroids if it coexists with preserved wall thickness.

BACKGROUND: Left ventricular (LV) diastolic dysfunction is frequently observed in patients with type 2 diabetes. Dipeptidyl peptidase-4 inhibitor (DPP-4i) attenuates postprandial hyperglycemia (PPH) and may have cardio-protective effects. It remains unclear whether DPP-4i improves LV diastolic function in patients with type 2 diabetes, and, if so, it is attributable to the attenuation of PPH or to a direct cardiac effect of DPP-4i. We compared the effects of the DPP-4i, sitagliptin, and the alpha-glucosidase inhibitor, voglibose, on LV diastolic function in patients with type 2 diabetes. METHODS: We conducted a prospective, randomized, open-label, multicenter study of 100 diabetic patients with LV diastolic dysfunction. Patients received sitagliptin (50 mg/day) or voglibose (0.6 mg/day). The primary endpoints were changes in the e' velocity and E/e' ratio from baseline to 24 weeks later. The secondary efficacy measures included HbA1c, GLP-1, lipid profiles, oxidative stress markers and inflammatory markers. RESULTS: The study was completed with 40 patients in the sitagliptin group and 40 patients in the voglibose group. There were no significant changes in the e' velocity and E/e' ratio from baseline to 24 weeks later in both groups. However, analysis of covariance demonstrated that pioglitazone use is an independent factor associated with changes in the e' and E/e' ratio. Among patients not using pioglitazone, e' increased and the E/e' ratio decreased in both the sitagliptin and voglibose groups. GLP-1 level increased from baseline to 24 weeks later only in the sitagliptin group (4.8 ± 4.7 vs. 7.3 ± 5.5 pmol/L, p < 0.05). The reductions in HbA1c and body weight were significantly greater in the sitagliptin group than in the voglibose group (-0.7 ± 0.6 % vs. -0.3 ± 0.4, p < 0.005; -1.3 ± 3.2 kg vs. 0.4 ± 2.8 kg, p < 0.05, respectively). There were no changes in lipid profiles and inflammatory markers in both groups. CONCLUSIONS: Our trial showed that sitagliptin reduces HbA1c levels more greatly than voglibose does, but that neither was associated with improvement in the echocardiographic parameters of LV diastolic function in patients with diabetes. TRIAL REGISTRATION: Registered at http://www.umin.ac.jp under UMIN000003784.

BACKGROUND: Previous studies have suggested that vasa vasorum (VV) is associated with plaque progression and vulnerability. OBJECTIVES: The aim of this study was to investigate the relationship between coronary neovascularization structures and plaque characteristics. METHODS: We included 53 patients who underwent optical coherence tomography to observe the proximal left anterior descending coronary artery. Patients were classified into 5 groups according to lesion characteristics: normal; fibrous plaque (FP); fibroatheroma (FA); plaque rupture (PR); and fibrocalcific plaque (FC). We defined signal-poor tubuloluminal structures recognized in cross-sectional and longitudinal profiles located in adventitial layer as VV, and within plaque as intraplaque neovessels. Two types of longitudinal microvascular structure (external running and internal running) and a particular type of intraplaque neovessels (a coral tree pattern) were noted. All VV and intraplaque neovessels were manually segmented followed by quantification with Simpson method. RESULTS: Among the groups, there was significant difference (expressed as median [interquartile range (IQR)]) in VV volume (normal: 0.329 [IQR: 0.209 to 0.361] mm(3), FP: 0.433 [IQR: 0.297 to 0.706] mm(3), FA: 0.288 [IQR: 0.113 to 0.364] mm(3), PR: 0.160 [IQR: 0.141 to 0.193] mm(3), and FC: 0.106 [IQR: 0.053 to 0.165] mm(3); p = 0.003) and intraplaque neovessels volume (normal: 0.00 [IQR: 0.00 to 0.00] mm(3), FP: 0.00 [IQR: 0.00 to 0.00] mm(3), FA: 0.028 [IQR: 0.019 to 0.041] mm(3), PR: 0.035 [IQR: 0.026 to 0.042] mm(3), and FC: 0.010 [IQR: 0.005 to 0.014] mm(3); p < 0.001). Significant differences were observed in the prevalence of the internal running (normal: 0.0%, FP: 28.6%, FA: 40.0%, PR: 70.0%, and FC: 40.0%; p = 0.032) and the coral tree pattern (normal: 0.0%, FP: 7.1%, FA: 40.0%, PR: 80.0%, and FC: 10.0%; p < 0.01). The VV volume correlated with fibrous plaque volume (r = 0.71; p < 0.01). CONCLUSIONS: VV increase with fibrous plaque volume and intraplaque neovessels with particular structures are associated with plaque vulnerability. Imaging for microvasculature could become a new window for plaque vulnerability.

BACKGROUND: The aim of this study was to determine whether two-dimensional speckle-tracking echocardiography can identify the myocardial damage detected by delayed enhancement (DE) magnetic resonance imaging via the differences in myocardial deformation in patients with extracardiac sarcoidosis who showed no structural and functional abnormalities in the heart. METHODS: Forty-five patients with biopsy-proven extracardiac sarcoidosis were analyzed retrospectively. Patients with abnormal electrocardiographic and echocardiographic findings, including ventricular arrhythmias, heart block, regional wall motion abnormalities, valvular heart disease, and cardiomyopathy, were excluded. Ten age-matched healthy control subjects were recruited as a control group. Comprehensive echocardiography and DE magnetic resonance imaging were performed, and circumferential, longitudinal, and radial strain were consecutively assessed using two-dimensional speckle-tracking echocardiographic software in a 16-segment model of the left ventricle in accordance to the presence (DE+) or absence (DE-) of DE. RESULTS: Among the 45 patients, 36 segments in 13 patients showed DE. DE+ segments had lower peak circumferential strain than DE- and control segments (-14 ± 5% vs -28 ± 7% vs -30 ± 7%, P < .0001). Peak longitudinal strain in DE+ segments was significantly decreased compared with control segments (-19 ± 4% vs -23 ± 5%, P = .005). However, peak radial strain was similar among the three groups: 41 ± 17% in DE+ segments, 45 ± 23% in DE- segments, and 46 ± 18% in control segments (P = .50). CONCLUSIONS: Circumferential and longitudinal strain via two-dimensional speckle-tracking echocardiography can identify the myocardial damage detected by DE magnetic resonance imaging in patients with extracardiac sarcoidosis.

Late gadolinium enhancement magnetic resonance imaging (LGE-MRI) has been established as a modality to detect myocardial infarction (MI). However, the use of gadolinium contrast is limited in patients with advanced renal dysfunction. Although the signal intensity (SI) of infarct area assessed by cine MRI is low in some patients with prior MI, the prevalence and clinical significance of low SI has not been evaluated. The aim of this study was to evaluate how low SI assessed by cine MRI may relate to the myocardial viability in patients with prior MI. Fifty patients with prior MI underwent both cine MRI and LGE-MRI. The left ventricle was divided into 17 segments. The presence of low SI and the wall motion score (WMS) of each segment were assessed by cine MRI. The transmural extent of infarction was evaluated by LGE-MRI. LGE was detected in 329 of all 850 segments (39%). The low SI assessed by cine MRI was detected in 105 of 329 segments with LGE (32%). All segments with low SI had LGE. Of all 329 segments with LGE, the segments with low SI showed greater transmural extent of infarction (78 [72 - 84] % versus 53 [38 - 72] %, P < 0.01), thinner wall (4.0[3.1 - 4.8] mm versus 6.5 [5.2 - 8.1] mm, P < 0.01), and higher WMS (4.0 [4.0 - 4.0] versus 2.0 [2.0 - 3.0], P < 0.01). The low SI assessed by cine MRI may be effective for detecting poorly viable myocardium in patients with prior MI.

BACKGROUND: We aimed to determine the predictive value of longitudinal, circumferential, and radial strains by two-dimensional speckle tracking echocardiography (2DSTE) for improvement in cardiac function after acute myocardial infarction (AMI) compared with that of contrast-enhanced cardiac magnetic resonance imaging (ceMRI). METHODS: In 35 patients with first-time AMI, myocardial viability was assessed to predict recovery of function at follow-up (7 ± 2 months), prospectively. For each left ventricular segment, each peak strains were determined using 2DSTE, and the relative extent of hyperenhancement was assessed using ceMRI. RESULTS: Of 176 segments with impaired function early after AMI, 99 segments showed regional recovery. Compared with segments showing functional improvement, those that failed to recover had lower peak radial (20 ± 16% vs. 32 ± 21%; P < 0.001), circumferential (-10 ± 5% vs. -20 ± 6%; P < 0.001), and longitudinal (-10 ± 5% vs. -14 ± 5%; P < 0.001) strain and a greater extent of hyperenhancement (71 ± 22% vs. 27 ± 20%; P < 0.001). Among strain parameters, circumferential strain yielded greater area under the curve (AUC; 0.899) than radial and longitudinal strain (0.682 and 0.718, respectively). The predictive value of circumferential strain (sensitivity 81.0%, specificity 79.6%, at a cutoff value of -14.3%) could be comparable to that of hyperenhancement (sensitivity 86.2%, specificity 83.9%, AUC 0.921, at a cutoff value of 47%) (P = 0.439). CONCLUSION: Circumferential strain can identify reversible myocardial dysfunction after AMI with a diagnostic ability comparable to that of ceMRI.

AIMS: The long-term safety of second-generation everolimus-eluting stents (EESs) in ST-segment elevation myocardial infarction (STEMI) remains unclear. The aim of this study was to evaluate the late vascular response after stent implantation in STEMI between EES and bare-metal stent (BMS) by using optical coherence tomography (OCT). METHODS AND RESULTS: A prospective OCT examination was performed in 102 patients at 10 months after stent implantation for treatment of STEMI. A total of 1253 frames with 12 772 struts in 61 EESs and 776 frames with 8594 struts in 41 BMSs were analysed. There were no significant differences in the percentage of uncovered struts (2.1 ± 2.8 vs. 1.7 ± 2.7%, P = 0.422) and malapposed struts (0.7 ± 1.3 vs. 0.6 ± 1.2%, P = 0.756) between EES and BMS. The frequency of intra-stent thrombus was comparable between the two stents (13 vs. 10%, P = 0.758). The mean neointimal thickness was smaller in EES compared with BMS (104 ± 39 vs. 388 ± 148 µm, P < 0.001). In-segment binary restenosis and target lesion revascularization was less often seen in EES compared with BMS (3 vs. 17%, P = 0.028 and 2 vs. 12%, P = 0.037, respectively). CONCLUSION: When compared with BMS, EES showed a lower rate of stent restenosis, similar frequency of neointimal coverage, stent malapposition, and intra-stent thrombus at 10 months after stent implantation in STEMI. Our results suggest the safety and effectiveness of EES in primary percutaneous coronary intervention for STEMI patients.

BACKGROUND: Blood glucose level at admission in ST-segment elevation myocardial infarction (STEMI) is a predictor of heart failure and mortality. A previous study showed the association between hyperglycemia and microvascular dysfunction using myocardial contrast echocardiography. Late gadolinium enhancement (LGE) cardiovascular magnetic resonance imaging (CMR) can demonstrate microvascular obstruction (MVO) as the area with hypointense core within LGE. This study was performed to investigate the association between hyperglycemia at admission and MVO using CMR in patients with STEMI. METHODS: Ninety-three patients with first STEMI who were treated by percutaneous coronary intervention (PCI) were included. CMR was performed within 7 days after PCI. Venous blood was collected routinely immediately after admission for plasma glucose determination before intravenous injection of some medications. Samples were analyzed in the hospital's central laboratory. We performed LGE-CMR to assess the presence of MVO. RESULTS: MVO was found in 34 (37%) of all 93 patients; their glucose level at admission was significantly higher than that of patients who did not exhibit MVO [204 (153-267)mg/dl vs. 157 (127-200)mg/dl, p=0.002]. There were no differences in glycosylated hemoglobin and incidence of diabetes mellitus between the two groups. A multivariable logistic regression analysis showed that glucose level at admission was an independent predictor of MVO (odds ratio, 1.014; 95% confidence interval, 1.004 to 1.023; p=0.006). The glucose level at admission 190mg/dl was the best threshold value for identifying MVO. The occurrence of MVO was significantly higher in the patients with glucose level at admission ≧190mg/dl compared with the patients with glucose level <190mg/dl [18 (53%) vs. 16 (27%), p=0.023]. CONCLUSIONS: Hyperglycemia at admission in STEMI patients who were treated by PCI was associated with the presence of MVO assessed by LGE-CMR.

AIM: Previous clinical trials have demonstrated the effectiveness of eicosapentaenoic acid (EPA) in preventing cardiovascular events. The aim of the present study was to investigate the effects of EPA treatment on the accumulation of coronary atherosclerotic plaque using optical coherence tomography (OCT). METHODS: A total of 46 acute coronary syndrome (ACS) patients without dyslipidemia were divided into two groups: those who received 1,800 mg/day of EPA (n = 15) or the control group (n = 31). Serial OCT examinations were performed at baseline and after eight months of follow-up. The target for the OCT analysis was non-culprit plaque with a percent diameter of stenosis of 30% to 70% in non-culprit vessels of ACS. RESULTS: Between the baseline and follow-up visits, the serum EPA levels increased (50 ± 26 mg/dL to 200 ± 41 mg/dL, p ＜ 0.001) in the EPA group, although they did not change in the control group. According to the OCT analysis, the lipid arc did not change in the EPA group (131 ± 52 degrees to 126 ± 54 degrees, p = 0.106) or the control group (137 ± 50 degrees to 138 ± 50 degrees, p=0.603). In contrast, the fibrous cap thickness significantly increased in both the EPA group (169 ± 70 μm to 201 ± 49 μm, p ＜ 0.001) and the control group (164 ± 63 μm to 174 ± 72 μm, p=0.018); however, the relative change in the fibrous cap thickness was significantly greater in the EPA group than in the control group (131 ± 35% vs. 106 ± 15%, p = 0.001). CONCLUSIONS: In the present study, the administration of EPA for eight months significantly increased the fibrous cap thickness in patients with coronary atherosclerotic plaque.

BACKGROUND: A strategy of deferred percutaneous coronary intervention for coronary stenosis with fractional flow reserve (FFR) 0.75-0.80, termed the gray zone, remains a matter of debate. The aim of this study was to assess the safety of deferring revascularization for patients with FFR 0.75-0.80 compared with those with FFR >0.80. METHODS AND RESULTS: We assessed 3-year clinical outcome in 150 patients with angiographically intermediate stenosis who had revascularization deferred on the basis of FFR ≥ 0.75 (FFR 0.75-0.80, n=56; FFR >0.80, n=94). Target vessel failure (TVF), defined as a composite of cardiac death, target vessel-related myocardial infarction (MI), and ischemia-driven target vessel revascularization (TVR) was evaluated during follow-up. Cardiac death was observed in 1 patient with FFR 0.75-0.80. There was no target vessel-related MI in either group. The incidence of ischemia-driven TVR was higher in patients with FFR 0.75-0.80 than in those with FFR >0.80 (14% vs. 3%, P=0.020). TVF-free survival was significantly worse for the patients with FFR 0.75-0.80 than those with FFR >0.80 (hazard ratio, 5.2; 95% confidence intervals: 1.4-19.5; P=0.015). CONCLUSIONS: Patients with FFR 0.75-0.80 were at higher risk of TVF mainly due to TVR than those with FFR >0.80.

BACKGROUND: The aim of the present study was to evaluate the feasibility of optical coherence tomography (OCT) for measurement of vessel area in coronary arteries with lipid-rich plaque as compared with intravascular ultrasound (IVUS). METHODS AND RESULTS: We investigated 80 coronary artery segments with lipid-rich plaque on OCT and non-attenuated plaque on IVUS. According to the lipid arc on OCT, the plaques were classified into 4 groups: group 1, lipid arc ≤90°; group 2, 90°<lipid arc≤180°; group 3, 180°<lipid arc≤270°; group 4, lipid arc >270°. Vessel circular arcs that could not be identified due to OCT signal attenuation were interpolated using an approximating algorithm. OCT-measured vessel area was well-correlated with IVUS-measured vessel area (R=0.834, P<0.001). On Bland-Altman plot, there was a good agreement between OCT-measured vessel area and IVUS-measured vessel area, although mean difference and limits of agreement increased with increase of lipid arc (mean difference in groups 1-4: -0.21, -0.31, -1.02, and -2.13 mm(2); lower limit: -1.49, -3.22, -5.24, and -9.25 mm(2); and upper limit: 1.07, 2.60, 3.20, and 4.99 mm(2)). Intra-observer (R=0.97-0.99, P<0.001) and inter-observer (R=0.97-0.99, P<0.001) reproducibility for OCT measurement of vessel area was excellent. CONCLUSIONS: Like IVUS, OCT can be used to measure vessel area in coronary arteries with lipid-rich plaque.

Cardiac resynchronization therapy (CRT) is an established therapy in patients with severe heart failure due to left ventricular (LV) dyssynchrony. Increasing stimulus strength (SS) of LV pacing could capture an enlarged myocardial area and provide rapid electrical conduction. The aim of the present study was to investigate whether increasing SS of LV pacing improves LV mechanical dyssynchrony and cardiac function in patients treated with CRT.We enrolled 26 patients with CRT and changed the SS of LV pacing: 2.5 V (standard SS) and 5 V (high SS). Electrocardiography and echocardiography were performed to assess QRS duration, LV mechanical dyssynchrony, and cardiac function under each condition.The QRS duration (138.6 ± 21.4 ms versus 126.8 ± 23.1 ms, P < 0.001), septal-posterior wall motion delay (126.5 ± 42.7 ms versus 111.4 ± 55.3 ms, P = 0.012), standard deviation of time from QRS (69.6 ± 21.8 ms versus 55.6 ± 19.4 ms, P < 0.001), LV ejection fraction (29.4 ± 10.6% versus 33.4 ± 11.6%, P = 0.005), and LV stroke volume (50.7 ± 15.5 mL versus 63.8 ± 18.3 mL, P < 0.001) improved significantly in high SS compared with standard SS.Increasing SS of LV pacing in CRT improves LV mechanical dyssynchrony and cardiac function. The capture of an enlarged myocardial area by increasing SS of LV pacing might offer an acute hemodynamic benefit to patients treated with CRT.

BACKGROUND: We aimed to evaluate whether specific monocyte subsets could serve as surrogate markers of disease activity in cardiac sarcoidosis (CS) evaluated by 18F-fluoro-2-deoxyglucose positron emission tomography (18F-FDG PET). METHODS AND RESULTS: We studied 28 patients with CS (8 men; mean age: 61±9 years) diagnosed according to consensus criteria. We divided the patients into 2 groups: known CS receiving corticosteroid therapy (Rx(+); n=13) and new-onset CS (Rx(-); n=15), and analyzed 3 distinct monocyte subsets (CD14+CD16-, CD14++CD16+, and CD14+ -CD16+). Monocyte subsets were also analyzed in 10 Rx(-) patients before and 12 weeks after starting corticosteroid therapy. Inflammatory activity was quantified by 18F-FDG PET using the coefficient of variation (COV) of the standardized uptake value (SUV). The proportion of CD14++CD16+ monocytes in Rx(+) patients (10.8 [0.2-23.5] %) was significantly lower than in Rx(-) patients (23.0 [11.5-38.4] %, P=0.001). After corticosteroid therapy, the COV of the SUV was significantly improved from 0.32 [0.14-0.62] to 0.17 [0.04-0.43] (P=0.017). The proportion of CD14++16+ monocytes showed a significant decrease from 22.2 [8.8-38.4] % to 8.4 [1.8-16.8] % (P=0.001). The decrease in the proportion of CD14++16+ monocytes significantly correlated with the decrease in the COV of the SUV (r=0.495, P=0.027). CONCLUSIONS: CD14++16+ monocytes are a possible surrogate marker of the therapeutic effect of corticosteroid therapy in CS.

BACKGROUND: The detailed mechanism of plaque stabilization by statin therapy is not fully understood. OBJECTIVES: The aim of this study was to assess the effect of lipid-lowering therapy with 20 mg/day of atorvastatin versus 5 mg/day of atorvastatin on fibrous cap thickness in coronary atherosclerotic plaques by using optical coherence tomography (OCT). METHODS: Seventy patients with unstable angina pectoris and untreated dyslipidemia were randomized to either 20 mg/day or 5 mg/day of atorvastatin therapy. OCT was performed to assess intermediate nonculprit lesions at baseline and 12-month follow-up. RESULTS: Serum low-density lipoprotein cholesterol level was significantly lower during therapy with 20 mg/day compared with 5 mg/day of atorvastatin (69 mg/dl vs. 78 mg/dl; p = 0.039). The increase in fibrous cap thickness was significantly greater with 20 mg/day compared with 5 mg/day of atorvastatin (69% vs. 17%; p < 0.001). The increase in fibrous cap thickness correlated with the decrease in serum levels of low-density lipoprotein cholesterol (R = -0.450; p < 0.001), malondialdehyde-modified low-density lipoprotein (R = -0.283; p = 0.029), high-sensitivity C-reactive protein (R = -0.276; p = 0.033), and matrix metalloproteinase-9 (R = -0.502; p < 0.001), and the decrease in grade of OCT-derived macrophages (R = -0.415; p = 0.003). CONCLUSIONS: Atorvastatin therapy at 20 mg/day provided a greater increase in fibrous cap thickness in coronary plaques compared with 5 mg/day of atorvastatin. The increase of fibrous cap was associated with the decrease in serum atherogenic lipoproteins and inflammatory biomarkers during atorvastatin therapy. (Effect of Atorvastatin Therapy on Fibrous Cap Thickness in Coronary Atherosclerotic Plaque as Assessed by Optical Coherence Tomography: The EASY-FIT Study; NCT00700037).

BACKGROUND: Computed tomographic (CT) angiography provides high sensitivity for the detection of coronary stenosis, while its specificity is relatively low. The aim of this study was to determine the incremental value of coronary flow velocity reserve (CFVR) by transthoracic echocardiography when used with CT angiography for detecting stenosis of the major coronary arteries compared with invasive quantitative coronary angiography. METHODS: Sixty patients who underwent CFVR measurement before coronary angiography were retrospectively selected, and the cutoff value of CFVR to predict diameter stenosis > 70% was determined using receiver operating characteristic curve analysis. Second, CFVR measurement and CT angiography were prospectively performed in 50 patients who were scheduled to undergo coronary angiography. CT angiography using a 64-detector row scanner and CFVR measurement in the proximal to middle portions of the three major coronary arteries by transthoracic echocardiography were performed on the same day, <48 hours before invasive angiography. RESULTS: The cutoff values of CFVR were determined to be 2.0 for the left anterior descending coronary artery and 2.1 for the circumflex and right coronary arteries. Using these determined cutoff values, the sensitivity, specificity, and positive and negative predictive value of CFVR to identify diameter stenosis ≥ 70% stenosis on invasive quantitative coronary angiography were determined to be 84%, 87%, 66%, and 95%, respectively, and those of CT angiography were 91%, 80%, 58%, and 97%, respectively, in the prospective study with 50 patients. The combination of ≥70% stenosis on CT angiography and impaired CFVR was 94% specific for ≥70% stenosis, while the presence of <70% stenosis on CT angiography and preserved CFVR was 100% specific for the exclusion of ≥70% stenosis on invasive quantitative coronary angiography. CONCLUSIONS: When the results of CT angiography and CFVR are concordant, the combination is highly accurate in the detection and exclusion of coronary stenosis. CFVR measurement in addition to CT angiography could be helpful in identifying false-positive CT angiographic results.

OBJECTIVES: The aim of this study was to investigate the impact of myocardial area supplied by the coronary artery on fractional flow reserve (FFR). BACKGROUND: Various factors other than the degree of epicardial stenosis influence the physiological significance of a coronary artery stenosis. METHODS: A total of 296 coronary lesions in 217 patients were analyzed by quantitative coronary angiography and FFR. Myocardial area supplied by the coronary artery distal to the stenosis was evaluated by angiography using a modified version of the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) score. RESULTS: Percent diameter stenosis of the coronary lesion was 57 ± 15% (mean ± standard deviation). FFR <0.80 was seen in 132 (45%) lesions. FFR was significantly correlated with minimum lumen diameter (r = 0.584, P <0.001), percent diameter stenosis (r = -0.565, P <0.001), lesion length (r = -0.306, P <0.001), and myocardial supply area (r = -0.504, P <0.001). Multivariate logistic analysis demonstrated that minimum lumen diameter (odds ratio [OR] = 0.031, 95% confidence interval [CI] = 0.013-0.076, P < 0.001), lesion length (OR = 1.038, 95% CI = 1.009-1.069, P = 0.001), and myocardial supply area (OR = 1.113, 95% CI = 1.079-1.147, P <0.001) were independent determinants for FFR <0.80. CONCLUSIONS: FFR, which is the index of physiological significance of coronary artery stenosis, is influenced by myocardial supply area distal to the stenosis as well as by its own minimal lumen diameter and lesion length.

BACKGROUND: Autopsy studies have reported that rupture of a thin-cap fibroatheroma and subsequent thrombus formation is the major mechanism leading to acute coronary syndrome (ACS). However, it is not clear why only some plaque ruptures lead to ACS. Optical coherence tomography (OCT) is a high-resolution imaging modality which is capable of investigating detailed coronary plaque morphology in vivo. The objective of this study was to determine whether ruptured plaque morphology assessed by OCT differs between asymptomatic coronary artery disease (CAD) and non-ST elevation acute coronary syndrome (NSTEACS). METHODS: We examined ruptured plaque morphology using OCT in 80 patients, 33 with asymptomatic CAD and 47 with NSTEACS. RESULTS: The frequency of lipid-rich plaque and intracoronary thrombus was significantly lower in asymptomatic CAD than in NSTEACS (61% vs. 85%, p = 0.013 and 9% vs. 83%, p < 0.001, respectively). Although maximal ruptured cavity cross-sectional area (CSA) was similar in both groups, lumen area at the rupture site and minimal lumen area were significantly larger in asymptomatic CAD than in NSTEACS (3.78 ± 1.50 mm(2) vs. 2.70 ± 1.55 mm(2), p = 0.003 and 2.75 ± 0.99 mm(2) vs. 1.72 ± 0.90 mm(2), p < 0.001, respectively). CONCLUSIONS: OCT revealed that the morphology of ruptured plaques differs between asymptomatic CAD and NSTEACS in terms of lumen area and the frequency of lipid-rich plaques and thrombi. These morphological features may be associated with the clinical presentation of CAD.

BACKGROUND: Alpha glucosidase inhibitor (GI) attenuates postprandial hyperglycemia (PPH) and reduces the risk of cardiovascular events in patients with impaired glucose tolerance or type 2 diabetes. Dipeptidyl peptidase 4 (DPP-4) inhibitors also attenuate PPH. PPH is one of the factors leading to endothelial dysfunction which is an early event in the pathogenesis of atherosclerosis. Furthermore, DPP-4 inhibitors protect endothelial function through a GLP-1-dependent mechanism. However, the impact of these two types of drugs on endothelial dysfunction in patients with type 2 diabetes has not been fully elucidated. We compared the effects of sitagliptin, a DPP-4 inhibitor, and voglibose, an alpha GI, on endothelial function in patients with diabetes. METHODS: We conducted a randomized prospective multicenter study in 66 patients with type 2 diabetes who did not achieve the treatment goal with sulfonylurea, metformin or pioglitazone treatment; 31 patients received sitagliptin treatment and 35 patients, voglibose treatment. The flow-mediated dilatation (FMD) of the brachial artery was measured in the fasting state at baseline and after 12 weeks of treatment. The primary endpoint was a change in FMD (ΔFMD) from the baseline to the end of follow-up. The effects of sitagliptin and voglibose on FMD were assessed by ANCOVA after adjustment for the baseline FMD, age, sex, current smoking, diabetes duration and body mass index. Secondary efficacy measures included changes in HbA1c, GIP, GLP-1, C-peptide, CD34, lipid profile, oxidative stress markers, inflammatory markers and eGFR and any adverse events. RESULTS: ΔFMD was significantly improved after 12 weeks of treatment in both groups, and there was no significant difference in ΔFMD between the two groups. There were no significant differences in changes in HbA1c, GIP, GLP-1, C-peptide, lipid profile, oxidative stress marker, inflammatory marker and eGFR between the two groups. Compared with voglibose, sitagliptin significantly increased the circulating CD34, a marker of endothelial progenitor cells. Adverse events were observed in 5 patients in only the voglibose group (diarrhea 1, nausea 1, edema 2 and abdominal fullness 1). CONCLUSIONS: Sitagliptin improved endothelial dysfunction just as well as voglibose in patients with type 2 diabetes. Sitagliptin had protective effects on endothelial function without adverse events. TRIAL REGISTRATION: registered at http://www.umin.ac.jp/ctrj/ under UMIN000003951.

AIMS: Coronary flow velocity reserve (CFVR) measurement in three major coronary arteries by transthoracic echocardiography is a promising and non-invasive method for detecting myocardial ischaemia. Its value when compared with fractional flow reserve (FFR) is unknown. Our aim was to determine the diagnostic accuracy of CFVR in three major coronary arteries for detecting ischaemia compared with FFR. METHODS: This is a prospective study in 172 vessels of 140 patients with at least one ≥50% stenosis in a major epicardial artery as determined by visual assessment on computed tomography coronary angiography. We performed CFVR measurement by transthoracic echocardiography within 48 h before coronary angiography and FFR measurement. The cut-off value of CFVR was estimated by the receiver operating characteristic (ROC) curve based on that of FFR ≤0.75. RESULTS: The CFVR was 1.86 ± 0.36 in coronary arteries with FFR ≤0.75 (n = 79) and 2.54 ± 0.48 in those with FFR >0.75 (n = 93, P < 0.0001). CFVR with cut-off of 2.2, determined by the ROC curve, was 85% sensitive and 79% specific in predicting the stenotic condition of the coronary artery with FFR ≤0.75 in three major vessels. In each vessel, the sensitivity and specificity were 85 and 78% (left anterior descending coronary artery), 94 and 83% (right coronary artery), and 88 and 88% (left circumflex coronary artery). CFVR was indirect proportional to FFR (r = 0.56, P < 0.0001) and to per cent diameter stenosis (r = 0.26, P = 0.0008). CONCLUSIONS: The non-invasive CFVR measurement could be a reliable stenosis-specific method for determining the haemodynamic significance of three major coronary arteries.

Histopathological studies have reported that optical coherence tomography (OCT) can accurately detect fibroatheroma that is involved in not only culprit lesion of acute coronary syndrome but also no-reflow phenomenon after percutaneous coronary intervention. Studies have demonstrated superiority of OCT in plaque characterization and interruption of arterial wall component. At current, multidetector computed tomography (MDCT) and virtual histology intravascular ultrasound (VH-IVUS) are considered as alternative imaging devices for coronary plaque characterization. This study aimed to compare the diagnostic accuracy for detecting fibroatheroma between MDCT and VH-IVUS using OCT as the reference standard. Forty-three lesions from 27 patients assessed by MDCT, VH-IVUS, and OCT were included in this study. Fibroatheroma was defined by OCT as a signal-poor region with a fast signal drop-off and little or no signal backscattering within the lesion. From 43 lesions, OCT revealed 21 fibroatheromas. Ring-like sign assessed by MDCT and positive remodeling assessed by IVUS were more frequently observed in OCT-fibroatheroma than non-OCT-fibroatheroma. The remodeling index of OCT-fibroatheroma assessed by MDCT and IVUS were higher than those of non-OCT-fibroatheroma. The sensitivity, specificity, positive predict values, negative predict values and accuracy of ring-like sign by MDCT and VH-IVUS for detecting OCT-fibroatheroma were 43, 95, 90, 64, 70 % and 71, 45, 56, 63, 58 %, respectively. Our results suggest that both accuracies of MDCT and VH-IVUS to detect OCT-fibroatheroma are insufficient. We need to apply appropriate device for searching vulnerable plaque.

The relation between albuminuria and coronary microvascular function in patients with chronic kidney disease (CKD) has not been fully investigated. Therefore, we sought to assess whether albuminuria is associated with coronary flow velocity reserve (CFVR) impairment in patients with CKD. Coronary flow study was prospectively performed in 175 patients with CKD. CFVR of the left anterior descending artery was measured to evaluate coronary microvascular function using transthoracic echocardiography. We divided the patients into 5 groups according to the stages of CKD and analyzed the effect of albuminuria. CFVR gradually decreased with an increase in CKD stages. CFVR in patients with albuminuria was lower than those without albuminuria. In groups with CKD stages 2 and 3, the patients with albuminuria showed lower CFVR than those without albuminuria. Multiple logistic regression analysis revealed that albuminuria, age, and gender were independently associated with CFVR impairment. Of these factors, albuminuria was the most powerful predictor with the risk ratio of 12.4 for CFVR impairment. In conclusion, the more the CKD stages progressed, the more severe CFVR was impaired. Albuminuria was associated with CFVR impairment in patients with CKD; even in mild-to-moderate CKD, patients with albuminuria showed further reduced coronary vasodilator capacity.

Previous studies have demonstrated the higher accuracy of frequency-domain optical coherence tomography (FD-OCT) for quantitative measurements in comparison with intravascular ultrasound (IVUS). However, those analyses were based on the cross-sectional images. The aim of this study was to assess the accuracy of FD-OCT for longitudinal geometric measurements of coronary arteries in comparison with IVUS. Between October 2011 and March 2012, we performed prospective FD-OCT and IVUS examinations in consecutive 77 patients who underwent percutaneous coronary intervention with single stent. Regression analysis and Bland-Altman analysis revealed an excellent correlation between the FD-OCT-measured stent lengths and IVUS-measured stent lengths (r = 0.986, p < 0.001; mean difference = -0.51 mm). There was an excellent agreement between the actual stent lengths and the FD-OCT-measured stent lengths (r = 0.993, p < 0.001) as well as between the actual stent lengths and the IVUS-measured stent lengths (r = 0.981, p < 0.001). The difference between the actual stent lengths and the FD-OCT-measured stent lengths was significantly smaller than that between the actual stent lengths and the IVUS-measured stent lengths (0.15 ± 0.68 vs. 0.70 ± 1.15 mm, p < 0.001). Both FD-OCT (mean difference = -0.04 and -0.04 mm, respectively) and IVUS (mean difference = -0.06 and -0.06 mm, respectively) showed an excellent intra-observer and inter-observer reproducibility for the stent length measurements. In conclusion, FD-OCT provides accurate longitudinal measurement with excellent intra-observer and inter-observer reproducibility. FD-OCT might be a reliable technique for longitudinal geometric measurement in human coronary arteries.

BACKGROUND: The aim of this study was to test whether acceleration time of systolic coronary flow velocity could contribute to the diagnosis of coronary stenosis in patients with microvascular dysfunction, on the basis of the hypothesis that systolic coronary flow is less influenced by microvascular function because of compressed myocardium. METHODS: Coronary flow velocity was assessed in the left anterior descending coronary artery during hyperemia with intravenous adenosine by echocardiography in 502 patients who were scheduled for coronary angiography because of coronary artery disease and significant valvular disease. Coronary flow velocity reserve (CFVR) and the percentage acceleration time (%AT), as the percentage of the time from the beginning to the peak of systolic coronary flow over systolic time during hyperemia, were calculated. The diagnostic ability of CFVR and %AT for angiographic coronary artery stenosis was then analyzed. As invasive substudies, fractional flow reserve and %AT by a dual-sensor (pressure and Doppler velocity) guidewire were measured simultaneously with %AT on transthoracic echocardiography (n = 14). RESULTS: Patients with coronary stenosis had significantly lower CFVR (1.7 ± 0.4) and greater %AT (65 ± 9%) compared with those without stenosis (2.6 ± 0.6 and 50 ± 13%, respectively). Percentage acceleration time by Doppler echocardiography was in good agreement with %AT (r = 0.98) and fractional flow reserve (r = 0.74) invasively measured by dual-sensor guidewire. Cutoff values of CFVR and %AT were determined as 2.0 and 60% in receiver operating characteristic curve analysis. The sensitivity, specificity, and accuracy of CFVR to detect coronary stenosis were 71.1%, 77.3%, and 75.4%, while those of %AT were 83.4%, 71.8%, and 75.4%, respectively. In addition, %AT provided high accuracy to detect coronary stenosis, especially in patients with previous myocardial infarctions, valvular disease, and left ventricular hypertrophy (81.1%, 84.1%, and 73.4%, respectively). CONCLUSIONS: The %AT of systolic coronary flow velocity is a promising marker to diagnose coronary stenosis in patients with microvascular dysfunction.