Teruyoshi Kume

Consensus standards for acquisition, measurement, and reporting of intravascular optical coherence tomography studies: a report from the International Working Group for Intravascular Optical Coherence Tomography Standardization and Validation.

OBJECTIVES The purpose of this document is to make the output of the International Working Group for Intravascular Optical Coherence Tomography (IWG-IVOCT) Standardization and Validation available to medical and scientific communities, through a peer-reviewed publication, in the interest of improving the diagnosis and treatment of patients with atherosclerosis, including coronary artery disease. BACKGROUND Intravascular optical coherence tomography (IVOCT) is a catheter-based modality that acquires images at a resolution of ~10 μm, enabling visualization of blood vessel wall microstructure in vivo at an unprecedented level of detail. IVOCT devices are now commercially available worldwide, there is an active user base, and the interest in using this technology is growing. Incorporation of IVOCT in research and daily clinical practice can be facilitated by the development of uniform terminology and consensus-based standards on use of the technology, interpretation of the images, and reporting of IVOCT results. METHODS The IWG-IVOCT, comprising more than 260 academic and industry members from Asia, Europe, and the United States, formed in 2008 and convened on the topic of IVOCT standardization through a series of 9 national and international meetings. RESULTS Knowledge and recommendations from this group on key areas within the IVOCT field were assembled to generate this consensus document, authored by the Writing Committee, composed of academicians who have participated in meetings and/or writing of the text. CONCLUSIONS This document may be broadly used as a standard reference regarding the current state of the IVOCT imaging modality, intended for researchers and clinicians who use IVOCT and analyze IVOCT data.

Assessment of Coronary Arterial Thrombus by Optical Coherence Tomography

We analyzed optical coherence tomographic (OCT) characteristics of different types of coronary thrombi that had been confirmed at postmortem histologic examination. We examined 108 coronary arterial segments of 40 consecutive human cadavers. OCT images of red and white thrombi were obtained and the intensity property of these thrombi was analyzed. Red and white thrombi were found in 16 (17%) and 19 (18%) of the 108 arterial segments, respectively. Red thrombi were identified as high-backscattering protrusions inside the lumen of the artery, with signal-free shadowing in the OCT image. White thrombi were identified as low-backscattering projections in the OCT image. There were no significant differences in peak intensity of OCT signal between red and white thrombi (130+/-18 vs 145+/-34, p=0.12). However, the 1/2 attenuation width of the signal intensity curve, which was defined as the distance from peak intensity to its 1/2 intensity, was significantly different between red and white thrombi (324+/-50 vs 183+/- 42 microm, p<0.0001). A cut-off value of 250 microm in the 1/2 width of signal intensity attenuation can differentiate white from red thrombi with a sensitivity of 90% and specificity of 88%. We present the first detailed description of the characteristics of different types of coronary thrombi in OCT images. Optical coherence tomography may allow us not only to estimate plaque morphology but also to distinguish red from white thrombi.

Comparisons of Baseline Demographics, Clinical Presentation, and Long-Term Outcome Among Patients With Early, Late, and Very Late Stent Thrombosis of Sirolimus-Eluting Stents Observations From the Registry of Stent Thrombosis for Review and Reevaluation (RESTART)

Background— Stent thrombosis (ST) after sirolimus-eluting stent implantation has not yet been adequately characterized, mainly because of its low incidence. Methods and Results— The Registry of Stent Thrombosis for Review and Reevaluation (RESTART) is a Japanese nationwide registry of sirolimus-eluting stent–associated ST comprising 611 patients with definite ST (early [within 30 days; EST], 322 patients; late [between 31 and 365 days; LST], 105 patients; and very late [>1 year; VLST], 184 patients). Baseline demographics, clinical presentation, and long-term outcome of sirolimus-eluting stent–associated ST were compared among patients with EST, LST, and VLST. Baseline demographics were significantly different according to the timing of ST. Characteristic demographic factors for LST/VLST versus EST identified by multivariable model were hemodialysis, end-stage renal disease not on hemodialysis, absence of circumflex target, target of chronic total occlusion, prior percutaneous coronary intervention, and age <65 years. For LST versus VLST, they were hemodialysis, heart failure, insulin-dependent diabetes mellitus, and low body mass index. Patients with LST had a significantly higher rate of Thrombolysis in Myocardial Infarction grade 2/3 flow (36%) at the time of ST than those with EST (13%) (P<0.0001) and VLST (17%; P<0.0001). Mortality rate at 1 year after ST was significantly lower in patients with VLST (10.5%) compared with those with EST (22.4%; P=0.003) or LST (23.5%; P=0.009). Conclusion— ST timing–dependent differences in baseline demographic features, Thrombolysis in Myocardial Infarction flow grade, and mortality rate suggest possible differences in the predominant pathophysiological mechanisms of ST according to timing after sirolimus-eluting stent implantation.

Assessment of the coronary calcification by optical coherence tomography

AIMS Optical coherence tomography (OCT) can delineate calcified plaque without artefacts. The aim of this study was to evaluate the ability of OCT to quantify calcified plaque in ex vivo human coronary arteries. METHODS AND RESULTS Ninety-one coronary segments from 33 consecutive human cadavers were examined. By intravascular ultrasound (IVUS), 32 superficial calcified plaques, defined as the leading edge of the acoustic shadowing appears within the most shallow 50% of the plaque plus media thickness, were selected and compared with corresponding OCT and histological examinations. The area of calcification was measured by planimetry. IVUS significantly underestimated the area of calcification compared with histological examination (y = 0.39x + 0.14, r = 0.78, p < 0.001). Although OCT slightly underestimated the area of calcification (y = 0.67x + 0.53, r = 0.84, p < 0.001), it showed a better correlation with histological examination than IVUS. CONCLUSIONS Both OCT and IVUS underestimated the area of calcification, but OCT estimates of the area of calcification were more accurate than those estimated by IVUS. Thus, OCT may be a more useful clinical tool to quantify calcified plaque.

Plaque Characteristics of Thin-Cap Fibroatheroma Evaluated by OCT and IVUS

OBJECTIVES The purpose of this study was to assess plaque characteristics of optical coherence tomography (OCT)-derived thin-cap fibroatheroma (TCFA) by integrated backscatter intravascular ultrasound (IB-IVUS). BACKGROUND Radiofrequency signal-derived IVUS tissue characterization technology has become clinically available and provided objective and quantitative plaque characteristics of the coronary vessel wall. Integrated backscatter IVUS is one of the tissue characterization methods that can possibly provide quantitative plaque characteristics of the OCT-derived TCFA. METHODS Eighty-one coronary lesions with plaque burden >40% were selected and analyzed with both IB-IVUS and OCT. The OCT-derived TCFA was defined as a presence of thin fibrous cap (<65 μm) overlying a signal-poor lesion with diffuse border representing a lipid-rich plaque. By conventional gray-scale IVUS, external elastic membrane (EEM) cross-sectional area (CSA), lumen CSA, plaque plus media (P+M) CSA, plaque burden and remodeling index were measured. By IB-IVUS, plaque characteristics were further classified as fibrosis, dense fibrosis, calcification, or lipid pool. RESULTS Optical coherence tomography identified 40 TCFAs (49%) and 41 non-TCFAs. The EEM CSA, P+M CSA, plaque burden, and remodeling index were significantly larger in OCT-derived TCFA than non-TCFA. By IB-IVUS, percentage lipid pool area (= lipid pool area/P+M CSA × 100) was significantly higher (62.4 ± 12.8% vs. 38.4 ± 13.1%, p<0.0001) and percentage fibrosis area (= fibrosis area/P+M CSA × 100) was significantly lower (34.6 ± 11.4% vs. 50.5 ± 8.7%, p<0.0001) in OCT-derived TCFA than non-TCFA. By receiver-operator characteristic curve analysis, percentage lipid pool area ≥55%, percentage fibrosis area ≤41%, and remodeling index ≥1.0 were predictors of OCT-derived TCFA. CONCLUSIONS The OCT-derived TCFA had larger plaque burden and positive remodeling with predominant lipid component and less fibrous plaque assessed by IB-IVUS.

C-Reactive protein predicts severity, progression, and prognosis of asymptomatic aortic valve stenosis

BACKGROUND C-Reactive protein (CRP) has been shown to play a pivotal role in the pathogenesis of atherosclerosis progression. The aim of this study was to assess whether CRP predicts severity, progression, and prognosis of aortic valve stenosis (AS). METHODS One hundred and thirty-five patients with asymptomatic AS were studied. Patients were diagnosed as mild (n = 18, aortic valve area [AVA] > or =1.5 cm(2)), moderate (n = 57, AVA 1.0-1.49 cm(2)), or severe AS (n = 60, AVA <1.0 cm(2)) by Doppler echocardiography. Patients with serial (baseline and at 1 year) echocardiographic examination (n = 47) were grouped as either slow (n = 22, DeltaAVA <-0.15 cm(2)/y) or rapid progression group (n = 25, DeltaAVA > or =-0.15 cm(2)/y). In addition, long-term prognosis was compared between patients with low CRP (n = 68, CRP <0.15 mg/dL) and those with high CRP (n = 67, CRP > or =0.15 mg/dL). RESULTS Baseline CRP was significantly higher in patients with severe AS than in those with mild or moderate AS (mild AS 0.17 +/- 0.43, moderate AS 0.22 +/- 0.28, severe AS 0.53 +/- 0.66 mg/dL, P = .001). By multivariate logistic regression analysis, CRP was an independent predictor of severe AS (odds ratio 3.51, P = .015). Similarly, CRP was significantly higher in the rapid progression group than in the slow progression group (0.56 +/- 0.76 vs 0.19 +/- 0.25 mg/dL, P = .004). Furthermore, long-term survival was significantly lower in the high CRP group than in the low CRP group (log rank: P < .001). CONCLUSION C-Reactive protein predicts severity, progression, and prognosis in patients with asymptomatic AS.

Fibrin Clot Visualized by Optical Coherence Tomography

Optical coherence tomography (OCT) is a recently developed optical imaging technique that provides high-resolution (≈10 to 20 μm) cross-sectional images of vessels.1 It has been reported that OCT images of white and red thrombus were characterized as backscattering protrusions in the coronary lumen.2 However, OCT characteristics of fibrin clot composed of fibrin material and few blood cells have not been described. The coronary arteries of a 75-year-old man …

Assessment of Macro- and Microcirculation in Contemporary Critical Limb Ischemia

Objectives: A paucity of data exists regarding manifestations of macro‐ and microcirculation in contemporary critical limb ischemia (CLI). The aim of this study was (1) to evaluate the differences in foot circulation based on angiographic findings, (2) to clarify the relationship between macro‐ and microcirculation, and (3) to investigate the effects of postural changes on micro as well as macrocirculation between the supine position to the dependent position. Methods: A total of 40 critically ischemic limbs in 29 patients were included in this study. Noninvasive evaluation of macrocirculation, based on the ankle brachial index (ABI) and ankle pressure, and microcirculation, using skin perfusion pressure (SPP), was performed in both the supine and dependent positions. Results: There was no significant difference in macro‐ and microcirculations between any angiographical involvements. In the supine position, dorsal SPP correlated significantly with ABI (P = 0.021, r = 0.363) and ankle‐pressure (P = 0.001, r = 0.495), whereas plantar SPP failed to correlate with ABI (P = 0.198, r = 0.208) or ankle‐pressure (P = 0.185, r = 0.214). In the dependent position, however, SPP showed no significant correlation with ABI and ankle pressure. Postural change from the supine to dependent position yielded a significant increase in SPP (dorsal: 37.2 ± 16.2 to 77.9 ± 17.7 mm Hg, P < 0.001; plantar: 33.6 ± 17.3 to 75.7 ± 18.3 mm Hg, P < 0.001) as well as ABI and ankle‐pressure (ABI: 0.70 ± 0.35 to 0.78 ± 0.42, P = 0.003; ankle‐pressure; 108 ± 61 to 111 ± 60 mm Hg, P = 0.038). The effect of postural change on SPP showed no difference between patients with and without any clinical and angiographical complications. Conclusions: Of microcirculation assessed, only dorsal SPP correlated significantly with macrocirculation in the supine position. Furthermore, postural change from the supine to dependent position produced a dramatic improvement in microcirculation due to the effects of gravity.

Carperitide Is Associated With Increased In-Hospital Mortality in Acute Heart Failure: A Propensity Score-Matched Analysis.

BACKGROUND Carperitide (α-human A-type natriuretic peptide) has been used for more than one-half of all acute heart failure (AHF) patients in Japan. However, its clinical effectiveness is not well documented. METHODS We retrospectively identified AHF patients presenting with acute onset or worsening of symptoms and admitted to 1 of the 3 participating hospitals. Propensity score-matched analysis was performed. The primary end point was in-hospital mortality. RESULTS Of all of the AHF patients included in this study, 402 (38.7%) were treated with carperitide, and in-hospital mortality rate for the total cohort was 7.6%. We matched 367 pairs of patients treated with and without carperitide according to propensity score. In this matched cohort, treatment with carperitide was associated with in-hospital mortality (odds ratio [OR] 2.13, 95% confidence interval [CI] 1.17-3.85; P = .013). Potentially more harmful effects were observed in elderly patients (OR 2.93, 95% CI 1.54-5.91). CONCLUSIONS Carperitide was significantly associated with increased in-hospital mortality rate in AHF patients. Our results strongly suggest the necessity for well designed randomized clinical trials of carperitide to determine its clinical safety and effectiveness.

Impact of right ventricular involvement on the prognosis of takotsubo cardiomyopathy

BACKGROUND Previous studies showed that patients with takotsubo cardiomyopathy had a higher long-term mortality rate than the general population and the incidence of in-hospital complications was higher in takotsubo cardiomyopathy with than without right ventricular (RV) involvement. This study was performed to investigate the long-term prognostic impact of RV involvement in takotsubo cardiomyopathy. METHODS AND RESULTS The clinical data of 113 patients (72.7 ± 11.4 years old, 84 females) with takotsubo cardiomyopathy were studied retrospectively. The patients were divided into two groups according to the presence (biventricular group, n = 21, 18.6%) or absence (classical group, n = 92, 81.4%) of RV involvement assessed by initial echocardiography. The end point was a composite of all-cause death, re-hospitalization due to heart failure, and recurrence of takotsubo cardiomyopathy. The in-hospital mortality rate was significantly higher in the biventricular group than the classical group (14.3 vs. 1.1%, respectively, P = 0.02). Kaplan-Meier analysis indicated a significantly lower event-free survival rate in the biventricular group than the classical group (log-rank, P < 0.001). On multivariate analysis, RV involvement was the only independent predictor of the end point (HR: 2.73, P = 0.026). CONCLUSION The rates of in-hospital and long-term events were significantly higher in takotsubo cardiomyopathy with than without RV involvement, and RV involvement was the independent predictor of the poor prognosis.