Towards the non-destructive analysis of multilayered samples: A novel XRF-VNIR-SWIR hyperspectral imaging system combined with multiblock data processing.

The new challenge in the investigation of cultural heritage is the possibility to obtain stratigraphical information about the distribution of the different organic and inorganic components without sampling. In this paper recently commercialized analytical set-up, which is able to co-register VNIR, SWIR, and XRF spectral data simultaneously, is exploited in combination with an innovative multivariate and multiblock high-throughput data processing for the analysis of multilayered paintings. The instrument allows to obtain elemental and molecular information from superficial to subsurface layers across the investigated area. The chemometric strategy proved to be highly efficient in data reduction and for the extraction and integration of the most useful information coming from the three different spectroscopies, also filling the gap between data acquisition and data understanding through the combination of principal component analysis (PCA), brushing, correlation diagrams and maps (within and between spectral blocks) on the low-level fused. In particular, correlation diagrams and maps provide useful information for the reconstruction of a stratigraphic structure without the need to take any sample, thanks to the effective account for inter-correlation among data (variables), which is able to effectively characterize the possible combinations of components located in the same depth level. The highly innovative technology and the data processing strategy are applied for the multi-level characterization of a complex painting reproduction as an illustrative pilot study.

Development of clinical simultaneous SPECT/MRI.

There is increasing clinical use of combined positron emission tomography and MRI, but to date there has been no clinical system developed capable of simultaneous single-photon emission computed tomography (SPECT) and MRI. There has been development of preclinical systems, but there are several challenges faced by researchers who are developing a clinical prototype including the need for the system to be compact and stationary with MRI-compatible components. The limited work in this area is described with specific reference to the Integrated SPECT/MRI for Enhanced stratification in Radio-chemo Therapy (INSERT) project, which is at an advanced stage of developing a clinical prototype. Issues of SPECT/MRI compatibility are outlined and the clinical appeal of such a system is discussed, especially in the management of brain tumour treatment.

Survival Benefits of Invasive Versus Conservative Strategies in Heart Failure in Patients With Reduced Ejection Fraction and Coronary Artery Disease: A Meta-Analysis.

BACKGROUND: Heart failure with reduced ejection fraction caused by ischemic heart disease is associated with increased morbidity and mortality. It remains unclear whether revascularization by either coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI) carries benefits or risks in this group of stable patients compared with medical treatment. METHODS AND RESULTS: We performed a meta-analysis of available studies comparing different methods of revascularization (PCI or CABG) against each other or medical treatment in patients with coronary artery disease and left ventricular ejection fraction ≤40%. The primary outcome was all-cause mortality; myocardial infarction, revascularization, and stroke were also analyzed. Twenty-one studies involving a total of 16 191 patients were included. Compared with medical treatment, there was a significant mortality reduction with CABG (hazard ratio, 0.66; 95% confidence interval, 0.61-0.72; P<0.001) and PCI (hazard ratio, 0.73; 95% confidence interval, 0.62-0.85; P<0.001). When compared with PCI, CABG still showed a survival benefit (hazard ratio, 0.82; 95% confidence interval, 0.75-0.90; P<0.001). CONCLUSIONS: The present meta-analysis indicates that revascularization strategies are superior to medical treatment in improving survival in patients with ischemic heart disease and reduced ejection fraction. Between the 2 revascularization strategies, CABG seems more favorable compared with PCI in this particular clinical setting.

Quantification of manual thrombus removal in patients with acute coronary syndromes: a study exploiting serial frequency domain-optical coherence tomography.

AIMS: Thrombus aspiration is useful in improving myocardial reperfusion in comparison to conventional percutaneous coronary intervention in patients with acute myocardial infarction. Nonetheless, assessment of thrombus aspiration efficacy is lacking. Aim of this study was to quantify by frequency domain optical coherence tomography (OCT) the amount of thrombus removal in patients with acute coronary syndromes undergoing manual thrombus aspiration, correlating it with the actual size of the retrieved material. METHODS: Twenty-five consecutive patients with acute coronary syndrome were enrolled. OCT assessment of thrombotic lesions was performed before and after thrombus aspiration and repeated after stent deployment. OCT thrombus assessment was based on an established scoring technique. The aspirated material was analyzed by histology, and its planimetry was correlated with OCT-derived thrombus removal. RESULTS: The percentage of thrombus removal [(prethrombus aspiration minus post-thrombus aspiration)/(prethrombus aspiration × 100)] was 48.9; the delta measurement of the removed thrombus calculated by OCT correlated well with the planimetry-measured aspirated material (r = 0.56, P < 0.01). CONCLUSION: The present study showed the following: the thrombus score derived by OCT measurements correlated reasonably well with the planimetry measure of surface area of the actual aspirated material; after thrombus aspiration a large amount of residual thrombus can be appreciated at the target lesion site; and tissue components such as cholesterol debris and inflammatory cells can often be retrieved during thrombus aspiration.

One- and twelve-month safety and efficacy outcomes of patients undergoing edge-to-edge percutaneous mitral valve repair (from the GRASP Registry).

The aim of this study was to report on the 30-day and 1-year outcomes of percutaneous mitral valve repair with the MitraClip technique in patients with grade ≥3+ mitral regurgitation (MR) at high risk for conventional surgical therapy enrolled in the prospective Getting Reduction of Mitral Insufficiency by Percutaneous Clip Implantation (GRASP) registry. Acute device success was defined as residual MR ≤2+ after clip implantation. The primary safety end point was the rate of major adverse events at 30 days. The primary efficacy end point was freedom from death, surgery for mitral valve dysfunction, or grade ≥3+ MR at 30 days and 1 year. A total of 117 patients were treated. Eighty-nine patients (76%) presented with functional MR and 28 patients (24%) with organic MR. Acute device success was observed in all patients. Device implantation time significantly diminished with experience and varied significantly between cases with 1 versus ≥2 clips. No procedural mortality was recorded. Major adverse events occurred in 4 patients at 30 days (4.3%). Deterioration to MR ≥3+ was recorded in 25% of patients with degenerative MR and 7% of those with functional MR at 1 year. No surgery for mitral valve dysfunction occurred within 1 year. Freedom from death, surgery for mitral valve dysfunction, or grade ≥3+ MR was 96.4% and 75.8% at 30 days and 1 year, respectively. No significant differences were noted in the primary efficacy end point between patients with degenerative MR and those with functional MR. In conclusion, percutaneous mitral valve repair with the MitraClip technique was shown to be safe and reasonably effective in 117 patients from a real-world setting.

Association between proximal stent edge positioning on atherosclerotic plaques containing lipid pools and postprocedural myocardial infarction (from the CLI-POOL Study).

Postprocedural myocardial infarction is an ominous complication of percutaneous coronary intervention (PCI). Despite several patient, lesion, and procedural factors that may affect its occurrence and severity, it is unclear if implanting a stent edge on a coronary lipid pool, as appraised by optical coherence tomography (OCT), adversely affects outcomes. The aim of this study was to assess the association between postprocedural myocardial infarction and the implantation of a stent edge on a lipid pool, as assessed by OCT. A database was screened for patients without ongoing myocardial infarctions; who underwent PCI with stenting for single, native, de novo lesions; without periprocedural side-branch occlusion or compromise; who underwent post-PCI OCT; and had postprocedural myocardial infarctions. These subjects were matched 1:1 with patients with similar features but without postprocedural myocardial infarctions. Plaque characterization with OCT was performed using established criteria. Specifically, lipid pools within stent edges were quantified by computing the number of involved quadrants and the degree of lipid arc on cross-sectional images. A total of 30 patients were included (15 with postprocedural myocardial infarctions and 15 controls without infarctions). Whereas no patient or control subject had lipid pools in correspondence to distal stent edges, landing of proximal stent edges on lipid pools was significantly more frequent in patients than in controls (10 [66%] vs 2 [13%], p = 0.009), Moreover, patients with postprocedural myocardial infarctions had more extensive lipid pools at proximal stent edges than those without postprocedural myocardial infarctions. Accordingly, lipid pool arc at proximal stent edge was significantly associated with peak post-PCI creatine kinase-MB/upper limit of normal ratio (Spearman's ρ = 0.49, p = 0.006). In conclusion, incomplete stent coverage of coronary lipid pools appears to be associated with an increased risk for postprocedural myocardial infarction in patients who undergo PCI.

Angiography alone versus angiography plus optical coherence tomography to guide decision-making during percutaneous coronary intervention: the Centro per la Lotta contro l'Infarto-Optimisation of Percutaneous Coronary Intervention (CLI-OPCI) study.

AIMS: Angiographic guidance for percutaneous coronary intervention (PCI) has substantial limitations. The superior spatial resolution of optical coherence tomography (OCT) could translate into meaningful clinical benefits. We aimed to compare angiographic guidance alone versus angiographic plus OCT guidance for PCI. METHODS AND RESULTS: Patients undergoing PCI with angiographic plus OCT guidance (OCT group) were compared with matched patients undergoing PCI with angiographic only guidance (Angio group) within 30 days. The primary endpoint was the one-year rate of cardiac death or myocardial infarction (MI). A total of 670 patients were included, 335 in the OCT group and 335 in the Angio group. OCT disclosed adverse features requiring further interventions in 34.7%. Unadjusted analyses showed that the OCT group had a significantly lower one-year risk of cardiac death (1.2% vs. 4.5%, p=0.010), cardiac death or MI (6.6% vs. 13.0%, p=0.006), and the composite of cardiac death, MI, or repeat revascularisation (9.6% vs. 14.8%, p=0.044). Angiographic plus OCT guidance was associated with a significantly lower risk of cardiac death or MI even at extensive multivariable analysis adjusting for baseline and procedural differences between the groups (OR=0.49 [0.25-0.96], p=0.037) and at propensity-score adjusted analyses. CONCLUSIONS: This observational study, the first ever formally to appraise OCT guidance for PCI decision-making, suggests that the use of OCT can improve clinical outcomes of patients undergoing PCI.

Reproducibility of coronary optical coherence tomography for lumen and length measurements in humans (The CLI-VAR [Centro per la Lotta contro l'Infarto-VARiability] study).

Frequency-domain optical coherence tomography (FD-OCT) is becoming a useful diagnostic tool for coronary imaging for quantitative coronary analysis. Second-generation FD-OCT produces detailed coronary lumen images. However, the reproducibility of coronary measurements using FD-OCT in humans has not been thoroughly explored. Our goal was to determine the intraobserver, interobserver, and interpullback reproducibility of the in vivo FD-OCT measurements of the lumen area and/or lesion length. Twenty-five patients undergoing coronary angioplasty were included. In all subjects, FD-OCT pullbacks (20 mm/s) were acquired twice from the same coronary segment different from the target lesion, at an interval of 5 minutes, with no other intervention. A total of 9,396 cross-sectional lumen area frames and the relative coronary lesion length of each pullback were analyzed off-line with dedicated software by 2 independent expert readers (A and B). We compared the lumen area and length measurements as follows: pullback 1, read by reader A twice at an interval of 7 days (intraobserver analysis); pullback 1, independently read by readers A and B (interobserver comparison); and pullback 1 versus pullback 2, read by reader A (interpullback comparison). The per-segment and per-frame analyses showed very high and significant correlation coefficients for the interobserver, intraobserver, and interpullback comparisons for the lumen area and lesion length (R ≥0.95 and p <0.001 in all cases). Accordingly, the Bland-Altman estimates of bias showed nonsignificant differences in the interobserver, intraobserver, and interpullback comparisons at all levels, with average biases never >0.150 mm(2) for the lumen area or 0.200 mm for the lesion length. In conclusion, coronary imaging using FD-OCT showed excellent reproducibility, with low intraobserver, interobserver, and interpullback variability for both lumen area and lesion length measurements in humans. Thus, FD-OCT can be proposed for precise analysis in the catheterization laboratory to guide decision making and in clinical trials focusing on imaging end points.

Echocardiography in low-resource rural tropical hospitals.

Cardiopathies are common in tropical regions and echocardiography could be of substantial value. However, it is difficult to practice. We suggest simple techniques with conventional instruments that are available in many rural hospitals, and describe the most common echocardiographic procedures and findings that can be undertaken with short training by non-cardiologist physicians.

Effect of diffusion-sensitizing gradient timings on the exponential, biexponential and diffusional kurtosis model parameters: in-vivo measurements in the rat thalamus.

OBJECT: To investigate whether spacing (Delta) and duration (delta) of the diffusion-sensitizing gradient pulses differentially affect exponential (D'), biexponential (D (slow), D (fast) and f (slow)) and diffusional kurtosis (D and K) model parameters. METHODS: Measurements were performed in the rat thalamus for b = 200-3,200 s mm(-2), sweeping Delta between 20 and 100 ms at delta = 15 ms, and delta between 15 and 50 ms at Delta = 60 ms. Linear regressions were performed for each model parameter vs. Delta or delta. RESULTS: Increasing Delta from 20 to 100 ms increases D' (from 0.64 to 0.70 x 10(-3) mm(2)s(-1)) and D (slow) (from 0.26 to 0.33 x 10(-3) mm(2)s(-1)), reduces K (from 0.57 to 0.53), and has no effects on D (fast), f (slow) or D. Increasing delta from 15 to 50 ms increases D (from 0.80 to 0.88 x 10(-3) mm(2)s(-1)), and has no effects on the other parameters. CONCLUSION: The parameters of the biexponential and diffusional kurtosis models are more sensitive than the exponential model to Delta and delta; however, observed effects are too small to account for the discrepancies found in literature.

A novel 3-d reconstruction system for the assessment of bifurcation lesions treated by the mini-crush technique.

BACKGROUND: Conventional two-dimensional angiography lacks the ability to properly image the true bifurcation geometry, and its percutaneous coronary intervention-induced changes in the clinical setting. METHODS AND RESULTS: A novel three-dimensional reconstruction system was investigated by retrospectively analyzing 39 lesions in 35 consecutive patients with coronary bifurcation disease treated with the mini-crush technique. At baseline, significant correlations were proved between two- and three-dimensional systems in terms of either reference vessel diameter (R(2)= 0.68 and 0.29 for main and side branches, respectively), minimum lumen diameter (R(2)= 0.73 and 0.36), stenosis diameter (R(2)= 0.69 and 0.29), and lesion length (R(2)= 0.48 and 0.58). These results were consistent with those observed after the procedure and at 8-month follow-up. Lesion length was significantly longer with the three-dimensional compared to the two-dimensional system for both main and side branches (P < 0.001, and P = 0.007, respectively). CONCLUSIONS: The three-dimensional quantitative reconstruction system may provide accurate evaluation of the complex curvilinear structure of bifurcation lesions when using a double stent technique.