Impact of combined supine and prone myocardial perfusion imaging using an ultrafast cardiac gamma camera for detection of inferolateral coronary artery disease.

BACKGROUND: Although combined supine and prone acquisitions improve the detection of inferolateral obstructive coronary artery disease (CAD), the predictors of inaccurate detection of inferolateral ischemia have not been reported by using cadmium zinc telluride (CZT) myocardial perfusion imaging (MPI). METHODS AND RESULTS: Vasodilator stress (99m)Tc tetrofosmin MPI using CZT camera and coronary angiography was performed in 322 patients within an interval of 2 months. Prone MPI was performed immediately after supine MPI. Narrowing of the luminal diameter ≥ 75% was considered significant. The presence of an abnormality on both supine and prone images was considered significant. Combined supine and prone imaging, compared with supine-only quantification, was more specific (93% vs. 72%, respectively, p<0.0001) and accurate (88% vs. 74%, p<0.0001) without compromising sensitivity (82% vs. 68%, p=0.10). The area under the curve for detecting inferolateral ischemia was 0.769 (95% CI 0.705-0.833) for supine imaging and 0.802 (95% CI 0.730-0.875) for combined supine and prone imaging (p<0.05). Multivariable analysis revealed that previous inferolateral myocardial infarction was an independent predictor of a false diagnosis (odds ratio=3.45, 95% confidence interval [CI] 1.62-7.37, p<0.001). CONCLUSIONS: Combined supine and prone quantitative CZT MPI enhances the detection of inferolateral CAD without adversely affecting its sensitivity. However, we recommend inferolateral ischemia be monitored in patients with a history of previous inferolateral MI because previous inferolateral MI is a predictor of inaccurate diagnosis.

Calcification analysis by intravascular ultrasound to define a predictor of left circumflex narrowing after cross-over stenting for unprotected left main bifurcation lesions.

OBJECTIVES: The aim of this study was to identify predictors of significant LCx-ostium compromise after distal unprotected left main coronary artery (ULMCA) stenting on the basis of baseline intravascular ultrasound (IVUS). BACKGROUND: Provisional single-stenting is considered as the default strategy for non-true bifurcation lesions in ULMCA. However, in certain cases, left circumflex artery (LCx)-ostium stenting is necessary. METHODS: A total of 77 patients underwent percutaneous coronary intervention with drug-eluting stents for non-true bifurcation lesions in ULMCA and had IVUS evaluation. Pre-procedural IVUS was performed to measure cross-sectional areas at the following segments: left main trunk, left anterior descending artery (LAD)-ostium. Post-stenting-narrowing at the circumflex ostium (PSN-LCx) was defined as the presence of more than 50% diameter stenosis at the LCx-ostium as determined by quantitative coronary angiography analysis. RESULTS: PSN-LCx occurred in 27 (35%) patients. The presence of calcified plaque at the culprit lesion as identified by IVUS was more frequently observed in the PSN-LCx group as compared to the non-PSN-LCx group (81.5% vs. 22.0%, p<0.001). Calcium arc in the PSN-LCx group was significantly greater than that in the non-PSN-LCx group (118.1°±69.9° vs. 36.9°±63.0°, p<0.001). On multivariable analysis, a calcium arc>60° was an independent predictor of PSN-LCx (odds ratio: 5.12, 95% confidence interval: 1.21-25.01, p=0.03). CONCLUSIONS: The presence of calcified plaque at the culprit lesion appears to be one of the factors involved in LCx-ostial compromise in non-true bifurcation ULMCA lesions, especially when the calcium arc is >60°.

The role of integrated backscatter intravascular ultrasound in characterizing bare metal and drug-eluting stent restenotic neointima as compared to optical coherence tomography.

BACKGROUND: To evaluate the role of integrated backscatter intravascular ultrasound (IB-IVUS) in assessing the morphology of neointima in bare-metal stent (BMS) and drug-eluting stent (DES) restenosis as compared to the gold-standard, optical coherence tomography (OCT). METHODS: A total of 120 cross-sections were evaluated by IB-IVUS and OCT at five cross-sections from 24 patients (24 lesions): at the minimal lumen area (MLA) and at 1 and 2mm proximal and distal to the MLA site in 24 lesions (9 treated with DES and 15 treated with BMS). IB-IVUS and OCT findings were analyzed according to the time at which restenosis was identified (early <12 months and late ≥12 months) and the stent type. RESULTS: IB-IVUS was found to correctly characterize the neointima of both BMS and DES in-stent restenosis (ISR) as compared to OCT. The overall agreement between the pattern of ISR neointima by IB-IVUS and that by OCT was excellent (kappa=0.85, 95% CI 0.76-0.94). Late DES ISR was characterized by more non-homogeneous, low backscatter and lipid-laden neointima, as compared to the BMS equivalent (BMS vs. DES, 45.0% vs. 80.0%, p<0.01; 51.7% vs. 85.0%, p=0.008; 33.3% vs. 65.0%, p<0.01, respectively). CONCLUSIONS: IB-IVUS assessment of the ISR neointima pattern appears to provide similar information as the gold-standard OCT in patients with stable angina. Both modalities suggested that late DES restenosis is characterized by a non-homogeneous lipid-laden neointima.

A fluorescent lectin array using supramolecular hydrogel for simple detection and pattern profiling for various glycoconjugates.

Because sugar and its derivatives play important roles in various biological phenomena, the rapid and high-throughput analysis of various glycoconjugates is keenly desirable. We describe herein the construction of a novel fluorescent lectin array for saccharide detection using a supramolecular hydrogel matrix. In this array, the fluorescent lectins were noncovalently fixed under semi-wet conditions to suppress the protein denaturation. It is demonstrated by fluorescence titration and fluorescence lifetime experiments that the immobilized lectins act as a molecular recognition scaffold in the hydrogel matrix, similar to that in aqueous solution. That is, a bimolecular fluorescence quenching and recovery (BFQR) method can successfully operate under both conditions. This enables one to fluorescently read-out a series of saccharides on the basis of the recognition selectivity and affinity of the immobilized lectins without tedious washing processes and without labeling the target saccharides. Simple and high-throughput sensing and profiling were carried out using the present lectin array for diverse glycoconjugates, which not only included a simple glucose, but also oligosaccharides, and glycoproteins, and, furthermore, the pattern recognition and profiling of several types of cell lysates were also accomplished.

pH-Responsive shrinkage/swelling of a supramolecular hydrogel composed of two small amphiphilic molecules.

A pH-responsive volume-change function was successfully introduced into a supramolecular hydrogel that contained GalNAc-appended (GalNAc=N-acetylgalactosamine) glutamate ester 1 by the simple mixing of it with an appropriate amount of 2 a or 2 b amphiphilic carboxylic acid. In the 1:1 mixture (1:2), the hydrogel swelled under neutral pH conditions, but shrank to almost half of its original volume under acidic pH conditions. The structure and pH response of the mixed hydrogel were characterized by using X-ray diffraction (XRD), confocal laser scanning microscopy (CLSM), transmission or scanning electron microscopy (TEM, SEM), and Fourier transform IR (FTIR) spectroscopy. Well-developed fibers formed a stable hydrogel by self-assembly, and under acidic conditions the charge of the carboxylic acid terminal (from the carboxylate anion) was neutralized and then these fibers became densely packed. This macroscopic pH response was also applied to the pH-triggered release of bioactive substances. In this mixed supramolecular hydrogel, the hydrogelator 1 provides a stable hydrogel structure and the additive 2 acts as a commander that is sensitive to an environmental pH signal. The present supramolecular copolymerization strategy should be useful for the construction of novel, stimuli-responsive, soft materials.

Molecular recognition in a supramolecular hydrogel to afford a semi-wet sensor chip.

This communication describes a new molecular recognition chip using a semi-wet microenvironment provided by a self-assembled hydrogel. On the basis of the evidence that the molecular recognition capability of artificial chemosensors are practically retained even in the hydrogel compared to those in aqueous solution, we miniaturized the functionalized hydrogel to produce an unprecedented molecular recognition chip. We believe that the present noncovalent immobilization method is generally applicable to many chemosensors, which leads to a unique semi-wet sensor chip suitable to convenient and high-throughput assay to plural analytes.