Abundance and potential sources of floating polystyrene foam macro- and microplastics around Japan.

Polystyrene foam is widely used due to its lightweight, impact resistance, and excellent thermal insulation properties. Meanwhile, weak adhesion between beads in polystyrene foam leads to fragmentation, generating a substantial amount of microplastics (<5 mm). Such polystyrene foam debris littered on beaches diminishes the aesthetic value of coastal areas, negatively impacting tourism. Due to its density lower than other plastics, polystyrene foam macroplastics float on the sea surface and, thus, they are significantly influenced by wind drag during oceanic transport. In contrast, polystyrene foam microplastics drifting beneath the sea surface are carried mostly by ocean currents. These properties of polystyrene foam macroplastics and microplastics hinder the elucidation of their transport, distribution, and fate in nature, despite their potential to adversely impact marine ecosystems. To elucidate the generation, transport, and fragmentation processes of polystyrene foam ocean plastics, we conducted concurrent visual observations and surface net towing from seven training vessels around Japan during 2014-2020. Overall, the abundances of polystyrene foam ocean plastics were higher in the Sea of Japan than in the North Pacific south of Japan. The average abundances of polystyrene foam microplastics and macroplastics were 0.33 pieces/m3 and 0.45 pieces/km, respectively, over the entire sea area around Japan. In the Sea of Japan, the peak abundances of polystyrene foam macroplastics occurred in upstream of the Tsushima Current, while the peak for microplastics occurred downstream, suggesting that continuous fragmentation occurred during transport between the two peaks. Backward-in-time particle tracking model experiments suggested that the sources of polystyrene foam macroplastics observed in the Sea of Japan included aquaculture buoys and styrene debris beached around the Tsushima Strait. The present study demonstrated that reducing the release of polystyrene foam aquaculture floats will likely diminish the abundance of ocean plastics in the Sea of Japan.

Features of Cerebral Infarction Due to Left Ventricular Thrombus.

Objective Left ventricular (LV) thrombus is a rare condition in acute cerebral infarction. The prevalence and features of cerebral infarction with LV thrombus are unclear. We explored the features of cerebral infarction due to LV thrombus. Methods In this single-center retrospective study, we investigated consecutive patients with acute ischemic stroke admitted within seven days of the onset who had LV thrombus found by transthoracic echocardiography (TTE). First, we calculated the prevalence of LV thrombus in patients with cardioembolic stroke (CES). Second, we investigated the baseline characteristics, including the TTE findings and features of cerebral infarction due to LV thrombus. Results From June 2012 to January 2019, a total of 5,693 patients were enrolled. Of these, 1,408 (25%) patients were diagnosed with CES. Of these 1,408 patients with CES, 13 (0.9%) had LV thrombus indicated by TTE, with dilative cardiomyopathy, subacute myocardial infarction, and old myocardial infarction present in 1 (8%), 2 (15%), and 10 (77%), respectively. The ejection fraction (EF) was 48.9% (25.3-64.7%). The maximum longitudinal size of LV thrombus was 13.4 (0.97-38.1) mm, and there was no correlation between the size of the LV thrombus and the EF. Regarding the features of cerebrovascular infarction, major vessel occlusion was observed in 10 (77%) patients. Six (46%) patients were found to have good outcomes (modified Rankin Scale 0-2) at 90 days after the onset. Conclusion LV thrombus was seen in 0.9% of patients with CES. Many of the patients with LV thrombus had major vessel occlusion.

Association between the Suita Score and Stroke Recurrence in Patients with First-ever Ischemic Stroke: A Prospective Cohort Study.

Objective The Suita score is used to predict the 10-year prognosis of developing coronary heart disease (CHD). This study examined the association between the Suita score and stroke recurrence within one year in Japanese patients who experienced first-ever ischemic stroke. Methods This prospective cohort study at a stroke center in Japan included patients who experienced first-ever acute ischemic stroke (AIS) or a transient ischemic attack (TIA). During hospitalization, the Suita score was measured as the main exposure. Patients with a ≥5% predicted CHD risk were classified into the high-risk group. The primary outcome was stroke recurrence within one year of the stroke onset. A multivariate Cox regression analysis was conducted and adjusted for confounding and prognostic factors. Results Among the 1,204 patients evaluated, 937 (78%) were classified as having a high risk of developing CHD. Stroke recurrence was observed in 66 patients during the follow-up period. In the multivariate analysis, after adjusting for confounding and prognostic factors, such as non-small vessel occlusion and prescription of lipid-lowering agents at the time of discharge, a ≥5% predicted CHD risk was associated with the 1-year stroke recurrence after the initial onset [adjusted hazard ratio (HR) =2.20, 95% confidence interval (CI) =1.00-4.91, p=0.049; adjusted HR=2.00, 95% CI=1.01-4.14, p=0.048; adjusted HR=0.42, 95% CI=0.24-0.73, p=0.002]. Conclusion The Suita score, adapted for use in ischemic stroke with the same mechanism, correlated with the short-term recurrence within one year. Our findings suggest that the Suita score may be useful for predicting the long-term prognosis of developing CHD as well as the short-term recurrence for patients with first-ever AIS and TIA.

The current state of marine debris on the seafloor in offshore area around Japan.

Marine debris on the seafloor has not been thoroughly investigated, and there is little information compared to other types of marine debris. We conducted bottom trawl surveys to determine the present situation of marine debris on the seafloor in offshore areas around Japan. The survey was conducted in three sea areas with different characteristics. As a result, it was found that the amount of marine debris in submarine canyons (2926.1 items/km2) was higher than on the continental shelf. It was revealed that most marine debris on the seafloor is comprised of plastic products, and that debris on the seafloor retains its condition for a long time (over 30 years) without deterioration. In addition, the type of marine debris is affected by the industries operating in each area. Continuing to investigate marine debris on the seafloor in more areas will contribute to solving the problem of marine debris.

Simultaneous observation of intermittent locomotion of multiple fish by fine-scale spatiotemporal three-dimensional positioning.

Recent advances in biotelemetry techniques, especially positioning methods, have revealed the detailed behaviour and movement of aquatic organisms. Behavioural intermittence in animal locomotion, such as the Lévy walk, is a popular topic in the field of movement ecology. Previous attempts to describe intermittent locomotion quantitatively have been constrained by the spatial and temporal resolution possible with conventional biotelemetry systems. This study developed a fine-scale spatiotemporal three-dimensional positioning method using a new biotelemetry system with a positional precision of <10 cm and positioning interval of <10 s. Using this proposed positioning method, the intermittent stop-and-go locomotion of Siebold's wrasses (Pseudolabrus sieboldi) was observed during travel from an unsuitable to a suitable location following displacement. The fish displayed behavioural intermittence in relocating to a suitable location. Initially, their movement halted for reorientation, after which they moved intermittently yet in a straight line to the suitable location. To test the positioning ability of the proposed method, data sets were resampled at intervals of 5, 10, 30, 60, and 300 s. Longer sampling intervals failed to identify reorientations and underestimated the number of stops, distance travelled, and speed. Overall, the results highlighted the adequacy and ability of the proposed positioning method to observe the intermittent locomotion of fish, such as stop-and-go behaviour, in a natural environment.

Brain Natriuretic Peptide and Particular Left Ventricle Segment Asynergy Associated with Cardioembolic Stroke from Old Myocardial Infarction.

BACKGROUND: It is important to determine the usage of anticoagulants by defining the actual risk of cardioembolic stroke in patients with old myocardial infarction. In the present study, we aimed to more precisely evaluate the risks of each segment associated with cardioembolic stroke using a 16-segment model. The usage of the plasma brain natriuretic peptide (BNP) associated with cardioembolic stroke was also evaluated in comparison with a left ventricle ejection fraction less than 40%. METHODS: There were a total of 190 ischemic stroke patients who had premorbid myocardial infarction. The study included a total of 143 ischemic stroke patients with old myocardial infarction who were available for evaluation and excluded patients with atrial fibrillation or acute myocardial infarction. Their left ventricle wall motion abnormality and the level of plasma BNP at their admission were analyzed. RESULTS: Hypertension and a plasma BNP level of 206.9 pg/mL or higher, determined from the receiver operating characteristic curve, were independently associated with cardioembolic stroke (χ(2) = 35.6, R(2) = .30, P < .001). Adjusting for these factors, statistically independent high risk was observed at the basal-inferior, basal-inferolateral, mid-anterior, mid-anteroseptal, apical-anterior, and apical-septal left ventricles. CONCLUSION: High plasma BNP levels and left ventricular wall motion abnormalities in the segments perfused with left anterior descending coronary artery or right coronary artery show a high risk for cardioembolic stroke in patients with old myocardial infarction. Considering these factors, it could be possible to more precisely define the risk of cardioembolic stroke and to perform appropriate antithrombotic treatments in old myocardial infarction patients.

Individuality embedded in the isolation calls of captive beluga whales (Delphinapterus leucas).

INTRODUCTION: Species with fission-fusion social systems tend to exchange individualized contact calls to maintain group cohesion. Signature whistles by bottlenose dolphins are unique compared to the contact calls of other non-human animals in that they include identity information independent of voice cues. Further, dolphins copy the signatures of conspecifics and use them to label specific individuals. Increasing our knowledge of the contact calls of other cetaceans that have a fluid social structure may thus help us better understand the evolutionary and adaptive significance of all forms of individually distinctive calls. It was recently reported that one type of broadband pulsed sounds (PS1), rather than whistles, may function as individualized contact calls in captive belugas. The objective of this study was to assess the function and individual distinctiveness of PS1 calls in an isolation context. Recordings were made from five captive belugas, including both sexes and various ages. RESULTS: PS1 was the predominant call type (38 % in total) out of five broader sound categories. One sub-adult and three adults had individually distinctive and stereotyped pulse repetition pattern in PS1; one calf showed no clear stereotyped pulse repetition pattern. While visual inspection of the PS1 power spectra uncovered no apparent individual specificity, statistical analyses revealed that both temporal and spectral parameters had inter-individual differences and that there was greater inter-individual than intra-individual variability. Discriminant function analysis based on five temporal and spectral parameters classified PS1 calls into individuals with an overall correct classification rate of 80.5 %, and the most informative parameter was the average Inter-pulse interval, followed by peak frequency. CONCLUSION: These results suggest that belugas use individually distinctive contact calls in an isolation context. If belugas encode signature information in PS1 calls, as seen in bottlenose dolphins, the pulse repetition pattern may be the carrier, as it is individually stereotyped and appears to require vocal development. This idea is supported by the finding that the average inter-pulse interval is the most powerful discriminator in discriminant analysis. Playback experiments will elucidate which parameters are perceived as individual characteristics, and whether one of the parameters functions as a signature.

Direct relationship of local C-reactive protein production and lipid pool characterized by integrated backscatter intravascular ultrasound: a preliminary observation.

BACKGROUND: Local production of C-reactive protein (CRP) in human coronary arterial plaque was reported as a possible marker for local inflammation and vulnerable plaque. Integrated backscatter intravascular ultrasound (IB-IVUS) plaque tissue characterization may detect vulnerable plaque with high local plaque inflammation. Thus, the aim of this study was to clarify the relationship between IB-IVUS-based plaque characteristics and local high-sensitivity C-reactive protein (hs-CRP) production in stable and unstable plaque. METHODS AND RESULTS: Eighteen patients (nine unstable angina/non-ST-segment elevation myocardial infarction and nine stable angina) were prospectively enrolled. Using the microcatheter, blood samples from the proximal and distal sites of the culprit lesion were obtained to measure local CRP production. Translesional hs-CRP was defined as distal hs-CRP minus proximal hs-CRP of the culprit lesion. Gray-scale and IB-IVUS analyses were carried out at the target lesion. The translesional hs-CRP level tended to be higher in the unstable angina group than in the stable angina group (0.026 ± 0.033 vs. 0.003 ± 0.007 mg/dl, P = 0.050). Gray-scale IVUS-derived indices did not correlate with translesional hs-CRP. However, % lipid pool area by IB-IVUS correlated positively (r = 0.54, P = 0.02) and % fibrosis area correlated negatively with the translesional hs-CRP level (r = -0.52, P = 0.03). CONCLUSION: Lipid pool area detected by IB-IVUS is correlated positively with the translesional hs-CRP level.

A comparison between 40 MHz intravascular ultrasound iMap imaging system and integrated backscatter intravascular ultrasound.

BACKGROUND: iMap is a newly developed intravascular ultrasound (IVUS) tissue characterization system based on pattern recognition of the radio frequency (RF) signals. PURPOSE: The purpose of this study was to compare tissue characterization between iMap and another previously validated tissue characterization system, integrated backscatter (IB)-IVUS in vivo and to clarify similarities and differences between these two methods. METHODS: A total of 31 lesions from 16 patients with ischemic heart disease were studied. IVUS imaging was performed using 40 MHz IVUS catheter. RF signals from each lesion were then exported to analyze tissue characterization using both iMap and IB-IVUS. By iMap, coronary plaque was classified into four categories, fibrotic, lipidic, necrotic, or calcified. By IB-IVUS, coronary plaque was classified into four categories, fibrosis, lipid pool, dense fibrosis, or calcification. After the images were acquired, IB-IVUS and iMap images were compared at exactly the same cross-sections. Because severe calcification is a perfect reflector, dense calcification lesions (>20%) were excluded. RESULTS: Both fibrotic and calcified by iMap correlated well with fibrosis and calcification by IB-IVUS (fibrotic vs. fibrosis: r(2)=0.522, p<0.001, calcified vs. calcification: r(2)=0.560, p<0.001). Although lipidic by iMap did not correlate with lipid pool by IB-IVUS, necrotic by iMap correlated well with lipid pool by IB-IVUS (r(2)=0.480, p<0.001). CONCLUSION: Although tissue types classified by iMap correlated well with corresponding tissue type by IB-IVUS, some discrepancy presented between the two systems. These results may call for careful interpretation of the tissue types obtained by the different IVUS tissue characterization systems.

Cerebral near-infrared spectroscopy to evaluate anti-G straining maneuvers in centrifuge training.

INTRODUCTION: Over the past decade, near-infrared spectroscopy (NIRS) has emerged as an easily manageable noninvasive method for the continuous monitoring of cerebral cortical oxygenation during +Gz exposure. NIRS is also used to evaluate pilot trainees' ability to adequately perform anti-G straining maneuvers in the course of centrifuge training. This study aimed to determine the general patterns and individual differences in NIRS recordings during +Gz exposure. METHODS: There were 22 healthy male cadets who participated in the study. The centrifuge training profiles included a gradual onset run (GOR, onset rate of 0.1 Gz x s(-1)) and short-term repeated exposures, with Gz levels from 4 to 7 Gz at an onset rate of 1.0 Gz x s(-1) (rapid onset run, ROR). Cortical tissue hemoglobin saturation (tissue oxygenation index, TOI) and changes in the concentration of oxygenated hemoglobin (O2Hb) were recorded from the right forehead during the period of Gz exposure. RESULTS: Most of the subjects successfully performed an anti-G straining maneuver and maintained or increased the cerebral oxygenation level during Gz exposure. In four subjects, however, oxygenation decline was observed at levels over 4 Gz, even though their anti-G systems were functioning. In contrast to the O2Hb response, TOI, which reflects intracranial oxygenation changes, was decreased during the anti-G straining maneuver at Gz onset or during the countdown to a ROR exposure. CONCLUSION: Although NIRS is an effective tool for monitoring anti-G straining maneuver performance, it should be carefully evaluated in terms of intracranial oxygenation results.

Short-range homing in a site-specific fish: search and directed movements.

Sedentary and territorial rockfish of the genus Sebastes exhibit distinctive homing ability and can travel back to an original location after displacements of metres or even kilometres. However, little is known about the behavioural and sensory mechanisms involved in homing. Although our previous study demonstrated that nocturnal black rockfish Sebastes cheni predominantly use their olfactory sense for homing from an unfamiliar area, the possibility of using landmarks in a familiar area cannot be discounted; i.e. site-specific fish are likely to use three-dimensional spatial memory for navigation and orientation. Using high-resolution acoustic telemetry, we investigated whether S. cheni exhibit distinctive homing paths. Results show that all of the eight rockfish increased their effort within a small area of an unfamiliar region around the release site just after displacement, suggesting that the rockfish probably searched for the homeward direction. The rockfish showed the search movement in the upstream and/or downstream direction, which did not lead home. Finally, after returning to their familiar area, the rockfish exhibited more directed movements with faster speeds at a shallower depth, which was similar to the depth utilised in daily life as well as that of the fish capture.

Statin inhibits hypoxia-induced endothelin-1 via accelerated degradation of HIF-1α in vascular smooth muscle cells.

AIMS: Endothelin-1 (ET-1) contributes to the pathogenesis of cardiovascular diseases with multiple properties such as vasoconstriction. Human ET-1 gene expression is up-regulated by the transcription factor hypoxia-inducible factor-1 (HIF-1) through hypoxia response element (HRE). Although previous studies suggested that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) alter HIF-1-related gene expression, it remained unclear whether statins modulate HIF-1-mediated ET-1 expression. Therefore, we investigated the effect of fluvastatin on hypoxia-induced human ET-1 expression in vascular smooth muscle cells (VSMC). METHODS AND RESULTS: Hypoxia (1% O(2)), compared with the normoxic condition (21% O(2)), significantly induced the expression of preproET-1 mRNA, ET-1 protein, and ET-1 secretion in VSMC. Hypoxia induced a 2.3-fold increase in HRE-dependent ET-1 reporter gene activation. Under concentrations of 1 µmol/L or greater, fluvastatin attenuated the hypoxia-induced ET-1 gene expression through the accelerated ubiquitin/proteasome-dependent degradation of HIF-1α, thus consequently attenuating HIF-1α binding to the HRE of the ET-1 gene. These inhibitory effects of fluvastatin were cancelled by concomitant treatment with mevalonate, farnesyl pyrophosphate, or geranylgeranyl pyrophosphate, but not squalene. CONCLUSION: The present study suggests that fluvastatin attenuates HIF-1-dependent ET-1 gene expression in conjunction with the stimulation of HIF-1α ubiquitin/proteasome-dependent degradation via isoprenoid-dependent mechanisms.

Natural history of stent edge dissection, tissue protrusion and incomplete stent apposition detectable only on optical coherence tomography after stent implantation ­ preliminary observation ­ .

BACKGROUND: The clinical impact of stent edge dissection, tissue protrusion, and incomplete stent apposition (ISA) after stent implantation, detectable only on optical coherence tomography (OCT), is still unknown because the natural course has not been investigated. METHODS AND RESULTS: All consecutive patients with angina pectoris in whom both intravascular ultrasound (IVUS) and OCT were performed immediately after stenting and at follow-up were included in the present study. The natural history of OCT-detected stent edge dissection, tissue protrusion, and ISA during follow-up was investigated. A total of 36 patients with 39 lesions was analyzed. At baseline, OCT showed 12 stent edge dissections, 25 tissue protrusions, and 8 ISAs, whereas IVUS demonstrated 6 stent edge dissections, 5 tissue protrusions, and 3 ISAs. All IVUS findings were clearly visualized on OCT. The maximum length of dissection flap and depth of ISA visualized on OCT were significantly shorter than those visualized on IVUS. Maximum length of tissue protrusion tended to be smaller on OCT than on IVUS. At follow-up (median 188 days), all findings noted on OCT were healed or resolved without any restenosis or thrombus formation. CONCLUSIONS: Acute findings after stenting, such as edge dissection, tissue protrusion, and ISA, detectable only on OCT, tended to be smaller than those seen on both OCT and IVUS. The majority of OCT-detected acute findings resolved completely at follow-up.

Decadal electrocardiographic changes between age 40 and 50 in military pilots.

INTRODUCTION: Cardiovascular diseases can lead to sudden in-flight incapacitation and long-term disability in aircraft pilots. Electrocardiogram (ECG) has been widely used to screen for these diseases in routine aeromedical examinations. Several ECG changes such as complete left bundle-branch block (CLBBB) and left ventricular hypertrophy (LVH) have been associated with increased likelihood of underlying structural cardiac diseases in addition to the emergence of newly recognized cardiovascular diseases such as Brugada syndrome. Therefore, the purpose of this study was to analyze decadal ECG changes in aircraft pilots between 40 and 50 yr in order to make an appropriate evaluation of these ECG changes. METHODS: We analyzed the ECGs from the annual aeromedical examination of age 50 compared to those 40 yr of age in a total of 176 Japan Air Self-Defense Force pilots. RESULTS: With regard to decadal changes, we detected 34 new ECG changes (1 of sinus tachycardia, 8 sinus bradycardia, 1 atrial fibrillation, 2 premature atrial contraction, 1 premature ventricular contraction, 2 left axis deviation, 6 first-degree atrioventricular block, 1 CLBBB, 3 complete right bundle-branch block, 2 incomplete right bundle-branch block, 1 right ventricular conduction delay, and 6 LVH). Although the majority of them were concluded to be normal variants, the results of echocardiography in two hypertensive pilots without good control demonstrated abnormalities: one had mild hypertrophic nonobstructive cardiomyopathy and another had heart enlargement. CONCLUSION: Thus, this study recommends additional cardiovascular examinations, including echocardiography for hypertensive pilots with ECG changes.

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.

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.

Relationship between arterial and fibrous cap remodeling: a serial three-vessel intravascular ultrasound and optical coherence tomography study.

BACKGROUND: Positive arterial remodeling and thin fibrous cap are characteristics of rupture-prone or vulnerable plaque. The natural course of the fibrous cap thickness and the relationship between serial arterial remodeling and changes in fibrous cap thickness are unknown. Therefore, the purpose of this study was to evaluate the relationship between changes in fibrous cap thickness and arterial remodeling by using optical coherence tomography (OCT) and intravascular ultrasound (IVUS) during 6-month follow-up. METHODS AND RESULTS: Both IVUS and OCT examinations were performed on 108 vessels from 36 patients with ischemic heart disease who underwent percutaneous coronary intervention. Fifty-eight fibroatheromas were selected from 82 nonsignificant, nonculprit lesions (angiographic diameter stenosis, 25% to 75%; plaque burden, >40% by IVUS). Fibroatheroma was defined by OCT as lipid-rich plaque in >1 quadrant that has lipid. Thickness of the fibrous cap was measured by OCT. IVUS and OCT examinations were repeated at 6-month follow-up. Serial changes and relationships between IVUS indices and fibrous cap thickness were investigated. Overall, fibrous cap thickness (98.1±38.9 to 96.9±44.5 µm) as well as IVUS indices did not change significantly within 6 months. The percent changes in fibrous cap thickness correlated negatively and significantly (r=-0.54; P<0.0001; generalized estimating equation adjusted, r=-0.42; P=0.001) with the percent changes in external elastic membrane cross-sectional area. CONCLUSIONS: Arterial remodeling is related to changes in fibrous cap thickness. Positive arterial remodeling is not only an adaptive process, but also related to thinning of the fibrous cap.

Coronary microvascular endothelial function deteriorates late (12 months) after sirolimus-eluting stent implantation.

BACKGROUND: Coronary flow velocity reserve (CFVR) may reflect coronary microvascular endothelial function in the absence of significant epicardial coronary artery stenosis. The purpose of this study was to evaluate coronary microvascular endothelial function late (6 and 12 months) after sirolimus-eluting stent (SES) implantation using transthoracic Doppler echocardiography. METHODS AND RESULTS: A total of 21 lesions from 21 patients with significant left anterior descending artery stenosis who underwent percutaneous coronary intervention (PCI) with SES were enrolled and studied. As a control group, 10 patients who were treated with bare metal stent (BMS) were also studied. CFVR was measured at 6 and 12 months after PCI. Coronary angiography was also performed at 6 and 12 months (SES only) after stenting. Between 6 and 12 months after SES implantation, there was no significant difference in angiographical diameter stenosis. On the other hand, CFVR significantly decreased between 6 and 12 months in the SES group (2.5±0.5 vs. 2.2±0.5, p<0.01), but not in the BMS group (2.3±0.4 vs. 2.5±0.3, p=0.1). CONCLUSIONS: Coronary microvascular endothelial function may deteriorate between 6 and 12 months after SES implantation.

Target lesion thin-cap fibroatheroma defined by virtual histology intravascular ultrasound affects microvascular injury during percutaneous coronary intervention in patients with angina pectoris.

BACKGROUND: Several reports suggest that virtual histology intravascular ultrasound (VH-IVUS) assessment could predict microvascular damage during percutaneous coronary intervention (PCI). A novel index of microcirculatory resistance (IMR) has been developed as a reproducible and less hemodynamic-dependent index. The purpose of this study was to investigate the relationship between thin-cap fibroatheroma (TCFA) defined by VH-IVUS and a change in the IMR during PCI in patients with angina pectoris (AP). METHODS AND RESULTS: The study investigated 30 lesions from 28 AP patients. VH-IVUS imaging was performed before PCI. TCFA was defined as the presence of confluent necrotic core (>10%) without detectable overlying fibrous cap segment. Patients were divided into 2 groups according to the presence of TCFA. Using a pressure guidewire, IMR were measured before and after PCI. After successful PCI, patients were prospectively followed up clinically. TCFA was detected in 9 lesions (30%). IMR tended to improve after PCI in the non-TCFA group, but tended to worsen in the TCFA group. DeltaIMR (=IMR after PCI-IMR before PCI) was significantly higher in the TCFA group compared with the non-TCFA group (13.2+/-29.9 vs -4.4+/-16.0, P=0.04). During follow-up (mean 20 months), survival free of major adverse cardiac events was significantly less in the TCFA group than in the non-TCFA group. CONCLUSIONS: Target lesion TCFA may be related to both microvascular injury and the long-term clinical outcome after successful PCI in patients with AP.

Quantitative measurements of aortic valve coaptation by three-dimensional transesophageal echocardiography in patients with aortic regurgitation without primary leaflet disease.

BACKGROUND: Aortic regurgitation (AR) without primary leaflet disease (functional AR) is known to occur as a result of loss of coaptation due to sinotubular junction (STJ) dilatation. However, the characteristics of change in the aortic valve coaptation length (AVCL) in 3 cusps in patients with functional AR are, as yet, unclear. The aim of this study was to measure the AVCL in 3 cusps in patients with functional AR by three-dimensional transesophageal echocardiograph (3D TEE). METHODS AND RESULTS: Thirteen patients with functional AR with or without aortic dilatation (trivial to mild AR [group A] and moderate to severe AR [group B]) and 7 controls without AR (group N) were examined. We measured the AVCL between the left coronary cusp (LCC) and right coronary cusp (RCC), the LCC and non coronary cusp (NCC), the RCC and NCC, and we also measured the cusp projection area, STJ arc length, leaflet tip-Valsalva wall distance and inter-commissural distance in each cusp by 3D TEE. The average AVCL was significantly shorter in group B than in groups N and A (P < 0.001). Particularly, in group B, there was a significant difference in AVCL in the 3 cusps (P = 0.043). Moreover, although there were no significant differences in the size of cusps in groups N and A, there was disproportion in the size of those cusps in group B with the largest in RCC. CONCLUSION: Cusp enlargement was not uniform and was greatest in the RCC, and the loss of coaptation between the 3 cusps was also not uniform, with predominant reduction in the coaptation between the RCC and the other 2 cusps.