The signal intensity of coronary culprit lesions on T1-weighted magnetic resonance imaging is directly correlated with the accumulation of vulnerable morphologies

BACKGROUND

In the magnetic resonance T1-weighted imaging, some investigators have shown that coronary artery high-intensity signals (HISs) are associated with vulnerable plaque morphology and an increased risk of future cardiac events. Although previous studies used different PMR (the ratio between the signal intensities of coronary plaque and cardiac muscle) cutoff values to detect HIS, the association between PMR itself and plaque morphology has not been fully investigated.

METHODS AND RESULTS

We prospectively investigated the association between PMR values and plaque morphology detected by optical coherence tomography in consecutive 106 patients with angina pectoris. The lesions with almost all of the vulnerable features such as lipid-rich, thin-cap fibroatheroma, plaque rupture, thrombus, macrophage infiltrations, intimal vasculature, and absence of calcification had significantly higher PMR; the only exception was the presence of cholesterol crystals. PMR increases linearly with the number of vulnerable features (p<0.0001, Rho=0.504). Stepwise multiple linear regression analysis revealed that the absence of calcification (p=0.0027), and the presence of thrombus (p=0.0071) and intimal vasculature (p=0.019) were independently associated with higher log-transformed PMR. There was a stepwise increase in PMR of the culprit lesions in proportion to the accumulation of the number of adverse plaque characteristics defined as non-calcified plaque, thrombus, and/or intimal vasculature.

CONCLUSION

These results suggest that not only the presence of HIS, but also the elevated PMR itself may be used as a quantitative marker of plaque vulnerability in clinical evaluation.

Cardio-ankle Vascular Index Associated with Coronary Plaque Burden not Plaque Morphology

Background Cardio-ankle vascular index (CAVI) is a marker that reflects the overall stiffness of the aorta, femoral artery, and tibial artery. Several previous reports have shown the usefulness of CAVI for coronary artery disease (CAD) presence and severity. According to coronary angiography (CAG) and intracoronary imaging such as optical coherence tomography (OCT), coronary plaque burden and morphology as predictors of all-cause and cardiovascular mortality were previously evaluated. The aim of our study was to assess the correlation between CAVI value and Gensini's score for the coronary plaque burden as well as CAVI value and plaque morphology by using OCT. Methods A total of 548 consecutive patients who underwent CAG were enrolled in this study. CAVI value was evaluated in all patients, and OCT was performed in 89 of the 548 patients. CAVI ratio is calculated as CAVI/CAVIex (expected normal value of CAVI, which is calculated using patient age and sex). Results On multivariable analysis, sex, age, hypertension, diabetes mellitus, and CAVI were significantly correlated with logarithmized Gensini's score. CAVI values were significantly higher in the groups with CAD, which were 1 vessel disease (VD), 2VD, and 3VD, than in the OVD group (p<0.001). However, there was no statistical significance between CAVI ratio and OCT findings in terms of plaque morphology. Conclusions CAVI might be useful as a routine test for the detection of CAD and the evaluation of atherosclerotic plaque burden but not coronary plaque vulnerability.

Atomic step-and-terrace surface of polyimide sheet for advanced polymer substrate engineering

Typical thermostable and flexible polyimide polymers exhibit many excellent properties such as strong mechanical and chemical resistance. However, in contrast to single-crystal substrates like silicon or sapphire, polymers mostly display disordered and rough surfaces, which may result in instability and degradation of the interfaces between thin films and polymer substrates. As a step toward the development of next-generation polymer substrates, we here report single-atom-layer imprinting onto the polyimide sheets, resulting in an ultrasmooth 0.3 nm high atomic step-and-terrace surface on the polyimides. The ultrasmooth polymer substrates are expected to be applied to the fabrication of nanostructures such as superlattices, nanowires, or quantum dots in nanoscale-controlled electronic devices. We fabricate smooth and atomically stepped indium tin oxide transparent conducting oxide thin films on the imprinted polyimide sheets for future use in organic-based optoelectronic devices processed with nanoscale precision. Furthermore, toward 2D polymer substrate nanoengineering, we demonstrate nanoscale letter writing on the atomic step-and-terrace polyimide surface via atomic force microscopy probe scratching.

The Clinical Value of High-Intensity Signals on the Coronary Atherosclerotic Plaques: Noncontrast T1-Weighted Magnetic Resonance Imaging

Over the past several decades, significant progress has been made in the pathohistological assessment of vulnerable plaques and in invasive intravascular imaging techniques. However, the assessment of plaque morphology by invasive modalities is of limited value for the detection of subclinical coronary atherosclerosis and the subsequent prediction or prevention of acute cardiovascular events. Recently, magnetic resonance (MR) imaging technology has reached a sufficient level of spatial resolution, which allowed the plaque visualization of large and static arteries such as the carotids and aorta. However, coronary wall imaging by MR is still challenging due to the small size of coronary arteries, cardiac and respiratory motion, and the low contrast-to-noise ratio between the coronary artery wall and the surrounding structures. Following the introduction of carotid plaque imaging with noncontrast T1-weighted imaging (T1WI), some investigators have reported that coronary artery high-intensity signals on T1WI are associated with vulnerable plaque morphology and an increased risk of future cardiac events. Although there are several limitations and issues that need to be resolved, this novel MR technique for coronary plaque imaging could influence treatment strategies for atherothrombotic disease and may be useful for understanding the pathophysiological mechanisms of atherothrombotic plaque formation.

Coronary plaque rupture with subsequent thrombosis typifies the culprit lesion of non-ST-segment-elevation myocardial infarction, not unstable angina: non-ST-segment-elevation acute coronary syndrome study

Recently, unstable angina pectoris (UAP) and non-ST-segment-elevation myocardial infarction (NSTEMI) have been considered together because they exhibit indistinguishable clinical and electrocardiogram features, and constitute non-ST-segment-elevation acute coronary syndrome (NSTE-ACS). However, no optical coherence tomography (OCT) studies have reported the association between vulnerable plaque morphology and clinical characteristics in NSTE-ACS patients based on assessment of clinical symptoms and myocardial necrosis. The aim of this study was to investigate the differences in clinical characteristics and plaque morphology assessed by OCT between patients with UAP and NSTEMI. Preinterventional OCT images of 84 NSTE-ACS patients were studied, 19 with NSTEMI and 65 with UAP, according to levels of high-sensitivity troponin T. The frequency of plaque rupture and thrombus in patients with NSTEMI was higher than in UAP patients with either class I or II + III (rupture: NSTEMI, 68 %; UAP classes II + III, 30 %; UAP class I, 19 %, thrombus: NSTEMI, 73 %; UAP classes II + III, 22 %; UAP class I, 14 %). In NSTEMI patients, the frequency of occurrence of both thrombus and rupture was the highest. Conversely, patients with UAP class I or those with UAP classes II + III most frequently had no thrombus and rupture, and the frequencies of the presence of thrombus were only 14 and 22 %, respectively. Multivariate analysis revealed that thrombus and plaque rupture were independently associated with NSTEMI. This study demonstrates that the morphological features of culprit lesions could be related to clinical severity in NSTE-ACS patients.

Development and analysis of patient-derived xenograft mouse models in intravascular large B-cell lymphoma

Intravascular large B-cell lymphoma (IVLBCL) is a distinct disease entity with the peculiar characteristic that tumor cells proliferate within vessels. Despite recent advances in understanding the disease from clinical aspects, the underlying pathogenesis remains unknown. Here we demonstrate analyses of IVLBCL biology using four xenograft mouse models established from primary IVLBCL samples. In all four models, the main characteristic of IVLBCL tumor cell proliferation within vessels was retained. Time-lapse engraftment analyses revealed that the tumor cells initially engrafted and proliferated in the sinusoids and vessels in the liver and then engrafted and proliferated in multiple organs. Intriguingly, serial passage of tumor cells from the adrenal gland of a transplanted mouse developed from primary patient bone marrow cells into a second mouse showed that the tumor cells mainly distributed into the adrenal gland in the second mouse, implying the existence of clonal selection and/or evolution at engraftment of a specific organ. Gene expression profiling analyses demonstrated that the gene set associated with cell migration was enriched for normal peripheral blood B cells, indicating that inhibition of cell migration might be involved in IVLBCL pathogenesis. In conclusion, the mouse xenograft models described here are essential tools for uncovering IVLBCL biology.

Successful treatment of very late drug-eluting stent thrombosis using bare-metal stent evaluated using intravascular ultrasound and optical frequency domain imaging

A 65-year-old man who underwent percutaneous coronary intervention with sirolimus-eluting stents (SESs) 2 years ago was admitted with recurrent acute chest pain. Coronary angiography showed thrombotic occlusion within the SESs. After aspiration thrombectomy, multi-focal peri-stent contrast staining (PSS) was observed. Optical frequency domain imaging (OFDI) showed intracoronary thrombus, incomplete stent apposition (ISA), and multiple inter-strut hollows. Intravascular ultrasound (IVUS) images showed positive vessel remodeling. We deployed bare-metal stents in the SESs. Follow-up angiography showed no in-stent restenosis or PSS. OFDI showed well-covered stent surface with homogeneous neointima, without ISA. Additionally, IVUS images showed that the vessel remodeling had not worsened.

New insights into spotty calcification and plaque rupture in acute coronary syndrome: an optical coherence tomography study

Although recent optical coherence tomography (OCT) studies have focused on spotty calcification, whether there were any characteristics in the concomitant existence of calcification and plaque rupture remains unknown. The aim of the present study was to investigate the characteristics of spotty calcification in acute coronary syndrome (ACS) patients with or without plaque rupture, using OCT. This study enrolled 98 consecutive patients with ACS. OCT image acquisitions were performed in the culprit lesions, and patients were divided into the plaque rupture group (n = 38) and the non-rupture group (n = 60). The frequency of spotty calcification (p = 0.006), thin-capped fibroatheroma (p = 0.012), macrophage infiltration (p = 0.022), and the number of spotty calcification per patient (p < 0.001) were significantly higher and the largest arc and the minimum depth of spotty calcification from the luminal surface were significantly smaller in the rupture group. Moreover, in the rupture group, most of the spotty calcifications in the site nearest to the minimum lumen area were observed in the proximal portion of that site, and tended to be located near the plaque rupture. Multivariate analysis revealed that the presence of spotty calcification (OR 3.19, 95 % CI 1.12-9.76, p = 0.030) and age (OR 1.08, 95 % CI 1.02-1.14, p = 0.008) were independent predictive factors for plaque rupture. This study demonstrates the characteristics of spotty calcification in ACS patients with plaque rupture and the positional relationship between spotty calcification and plaque rupture. These detailed observations could impact on treatment strategies for the prevention of ACS.

Randomized clinical trial comparing long-term quality of life for Billroth I versus Roux-en-Y reconstruction after distal gastrectomy for gastric cancer

BACKGROUND

Patients' quality of life (QoL) deteriorates remarkably after gastrectomy. Billroth I reconstruction following distal gastrectomy has the physiological advantage of allowing food to pass through the duodenum. It was hypothesized that Billroth I reconstruction would be superior to Roux-en-Y reconstruction in terms of long-term QoL after distal gastrectomy. This study compared two reconstructions in a multicentre prospective randomized clinical trial to identify the optimal reconstruction procedure.

METHODS

Between January 2009 and September 2010, patients who underwent gastrectomy for gastric cancer were randomized during surgery to Billroth I or Roux-en-Y reconstruction. The primary endpoint was assessment of QoL using the Functional Assessment of Cancer Therapy - Gastric (FACT-Ga) questionnaire 36 months after surgery.

RESULTS

A total of 122 patients were enrolled in the study, 60 to Billroth I and 62 to Roux-en-Y reconstruction. There were no differences between the two groups in terms of postoperative complications or mortality, and no significant differences in FACT-Ga total score (P = 0·496). Symptom scales such as epigastric fullness (heaviness), diarrhoea and fatigue were significantly better in the Billroth I group at 36 months after gastrectomy (heaviness, P = 0·040; diarrhoea, P = 0·046; fatigue, P = 0·029). The rate of weight loss in the third year was lower for patients in the Billroth I group (P = 0·046).

CONCLUSION

The choice of anastomotic reconstruction after distal gastrectomy resulted in no difference in long-term QoL in patients with gastric cancer.

REGISTRATION NUMBER

NCT01065688 (http://www.clinicaltrials.gov).

Developments of fast emittance monitors for ion sources at RCNP

Recently, several developments of low energy beam transport line and its beam diagnostic systems have been performed to improve the injection efficiency of ion beam to azimuthally varying field cyclotron at Research Center for Nuclear Physics, Osaka University. One of those is the fast emittance monitor which can measure within several seconds for the efficient beam development and a Pepper-Pot Emittance Monitor (PPEM) has been developed. The PPEM consists of pepper-pot mask, multichannel plate, fluorescent screen, mirror, and CCD camera. The CCD image is taken via IEEE1394b to a personal computer and analyzed immediately and frequently, and then real time measurement with about 2 Hz has been achieved.

A randomized phase II study of S-1 plus oral leucovorin versus S-1 monotherapy in patients with gemcitabine-refractory advanced pancreatic cancer

This is the first phase II trial in which adding oral leucovorin (LV) to S-1 (SL) significantly prolonged progression-free survival (PFS) when compared with S-1 monotherapy (S) in patients with gemcitabine-refractory advanced pancreatic cancer (PC). The significantly better PFS and disease control rate with SL than with S suggest that the antitumor activity of S-1 is enhanced by LV in advanced PC.

Background

We evaluated the efficacy and toxicity of adding oral leucovorin (LV) to S-1 when compared with S-1 monotherapy in patients with gemcitabine-refractory pancreatic cancer (PC).

Patients and methods

Gemcitabine-refractory PC patients were randomly assigned in a 1:1 ratio to receive S-1 at 40, 50, or 60 mg according to body surface area plus LV 25 mg, both given orally twice daily for 1 week, repeated every 2 weeks (SL group), or S-1 monotherapy at the same dose as the SL group for 4 weeks, repeated every 6 weeks (S-1 group). The primary end point was progression-free survival (PFS).

Results

Among 142 patients enrolled, 140 were eligible for efficacy assessment (SL: n = 69 and S-1: n = 71). PFS was significantly longer in the SL group than in the S-1 group [median PFS, 3.8 versus 2.7 months; hazard ratio (HR), 0.56; 95% confidence interval (CI), 0.37–0.85; P = 0.003]). The disease control rate was significantly higher in the SL group than in the S-1 group (91% versus 72%; P = 0.004). Overall survival (OS) was similar in both groups (median OS, 6.3 versus 6.1 months; HR, 0.82; 95% CI, 0.54–1.22; P = 0.463). After adjusting for patient background factors in a multivariate analysis, OS tended to be better in the SL group (HR, 0.71; 95% CI, 0.47–1.07; P = 0.099). Both treatments were well tolerated, although gastrointestinal toxicities were slightly more severe in the SL group.

Conclusion

The addition of LV to S-1 significantly improved PFS in patients with gemcitabine-refractory advanced PC, and a phase III trial has been initiated in a similar setting.

Clinical trials number

Japan Pharmaceutical Information Center: JapicCTI-111554.

Calculating disability-adjusted life years (DALY) as a measure of excess cancer risk following radiation exposure

This paper has proposed that disability-adjusted life year (DALY) can be used as a measure of radiation health risk. DALY is calculated as the sum of years of life lost (YLL) and years lived with disability (YLD). This multidimensional concept can be expressed as a risk index without a probability measure to avoid the misuse of the current radiation detriment at low doses. In this study, we calculated YLL and YLD using Japanese population data by gender. DALY for all cancers in Japan per 1 Gy per person was 0.84 year in men and 1.34 year in women. The DALY for all cancers in the Japanese baseline was 4.8 in men and 3.5 in women. When we calculated the ICRP detriment from the same data, DALYs for the cancer sites were similar to the radiation detriment in the cancer sites, excluding leukemia, breast and thyroid cancer. These results suggested that the ICRP detriment overestimate the weighting fraction of leukemia risk and underestimate the weighting fraction of breast and thyroid cancer. A big advantage over the ICRP detriment is that DALY can calculate the risk components for non-fatal diseases without the data of lethality. This study showed that DALY is a practical tool that can compare many types of diseases encountered in public health.

Localization of Coronary High-Intensity Signals on T1-Weighted MR Imaging: Relation to Plaque Morphology and Clinical Severity of Angina Pectoris

OBJECTIVES

This study sought to investigate the relationship between localization of high-intensity signals (HISs) on T1-weighted imaging (T1WI) with the noncontrast magnetic resonance technique and plaque morphology detected on optical coherence tomography, and the clinical severity of angina pectoris.

BACKGROUND

Since the introduction of the T1WI noncontrast magnetic resonance technique for plaque imaging, some groups have reported that HISs in the coronary artery on T1WI are associated with a vulnerable morphology and future cardiac events. However, the association between the localization of HISs, such as coronary intrawall or intraluminal, and plaque morphology has not been investigated.

METHODS

One hundred lesions with either stable or unstable angina were included and divided into 3 groups according to the following criteria using T1WI. First, the plaques with the ratio between the signal intensities of coronary plaque and cardiac muscle ≤1.0 were classified as non-HISs (n = 39). Then, HISs with the ratio between the signal intensities of coronary plaque and cardiac muscle >1.0 were classified into 2 types by using cross-sectional T1WI. Those localized within the coronary wall when the lumen was identified were defined as intrawall HISs (n = 37), whereas those occupying the lumen when the lumen was not, or even if only partly, identified, were defined as intraluminal HISs (n = 24).

RESULTS

Multivariate analysis revealed that intrawall HISs were associated with macrophage accumulation and the absence of calcification assessed by using optical coherence tomography. In contrast, thrombus and intimal vasculature were independent factors associated with intraluminal HISs. Furthermore, 50% of patients with intraluminal HISs experienced rest angina, such as Braunwald class II or III.

CONCLUSIONS

This study shows that intrawall and intraluminal HISs on T1WI in patients with angina are related to the different types of vulnerable plaque morphology and the clinical severity.

Comparison of effects of sitagliptin and voglibose on left ventricular diastolic dysfunction in patients with type 2 diabetes: results of the 3D trial

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