Near-infrared Spectroscopy Imaging Research Articles

Unveiling the link: exploring muscle oxygen saturation in fibromyalgia and its implications for symptomatology and therapeutic strategies

Fibromyalgia, characterized as a complex chronic pain syndrome, presents with symptoms of pervasive musculoskeletal pain, significant fatigue, and pronounced sensitivity at specific anatomical sites. Despite extensive research efforts, the origins of fibromyalgia remain enigmatic. This narrative review explores the intricate relationship between muscle oxygen saturation and fibromyalgia, positing that disruptions in the oxygenation processes within muscle tissues markedly influence the symptom profile of this disorder. Muscle oxygen saturation, crucial for muscle function, has been meticulously investigated in fibromyalgia patients through non-invasive techniques such as near-infrared spectroscopy and magnetic resonance imaging. The body of evidence consistently indicates substantial alterations in oxygen utilization within muscle fibers, manifesting as reduced efficiency in oxygen uptake during both rest and physical activity. These anomalies play a significant role in fibromyalgia’s symptomatology, especially in terms of chronic pain and severe fatigue, potentially creating conditions that heighten pain sensitivity and accumulate metabolic byproducts. Hypothesized mechanisms for these findings encompass dysfunctions in microcirculation, mitochondrial irregularities, and autonomic nervous system disturbances, all meriting further research. Understanding the dynamics of muscle oxygen saturation in fibromyalgia is of paramount clinical importance, offering the potential for tailored therapeutic approaches to alleviate symptoms and improve the quality of life for sufferers. This investigation not only opens new avenues for innovative research but also fosters hope for more effective treatment strategies and improved outcomes for individuals with fibromyalgia.

Altered Functional Connectivity of Temporoparietal Lobe in Obstructive Sleep Apnea: A Resting-State fNIRS Study.

Obstructive Sleep Apnea (OSA), a sleep disorder with high prevalence, is normally accompanied by affective, autonomic, and cognitive abnormalities, and is deemed to be linked to functional brain alterations. To investigate alterations in brain functional connectivity properties in patients with OSA, a comparative analysis of global and local topological properties of brain networks was conducted between patients with OSA and healthy controls (HCs), utilizing functional near-infrared spectroscopy (fNIRS) imaging. A total of 148 patients with OSA and 150 healthy individuals were involved. Firstly, quantitative alterations in blood oxygen concentration, changes in functional connectivity, and variations in graph theory-based network topological characteristics were assessed. Then, with Mann-Whitney statistics, this study compared whether there are significant differences in the above characteristics between patients with OSA and HCs. Lastly, the study further examined the correlation between the altered characteristics and the apnea hypopnea index (AHI) using linear regression. Results revealed a higher mean and standard deviation of hemoglobin concentration in the superior temporal gyrus among patients with OSA compared to HCs. Resting-state functional connectivity (RSFC) exhibited a slight increase between the superior temporal gyrus and other specific areas in patients with OSA. Notably, neither patients with OSA nor HCs demonstrated significant small-world network properties. Patients with OSA displayed an elevated clustering coefficient (p < 0.05) and local efficiency (p < 0.05). Additionally, patients with OSA exhibited a tendency towards increased nodal betweenness centrality (p < 0.05) and degree centrality (p < 0.05) in the right supramarginal gyrus, as well as a trend towards higher betweenness centrality (p < 0.05) in the right precentral gyrus. The results of multiple linear regressions indicate that the influence of the AHI on RSFC between the right precentral gyrus and right superior temporal gyrus (p < 0.05), as well as between the right precentral gyrus and right supramarginal gyrus (p < 0.05), are statistically significant. These findings suggest that OSA may compromise functional brain connectivity and network topological properties in affected individuals, serving as a potential neurological mechanism underlying the observed abnormalities in brain function associated with OSA.

A Review of Quantitative and Topical Analysis of Anthocyanins in Food.

Anthocyanins, a subclass of flavonoids known for their vibrant colors and health-promoting properties, are pivotal in the nutritional science and food industry. This review article delves into the analytical methodologies for anthocyanin detection and quantification in food matrices, comparing quantitative and topical techniques. Quantitative methods, including High-performance Liquid Chromatography (HPLC) and Mass Spectrometry (MS), offer precise quantification and profiling of individual anthocyanins but require sample destruction, limiting their use in continuous quality control. Topical approaches, such as Near-infrared Spectroscopy (NIR) and hyperspectral imaging, provide rapid, in situ analysis without compromising sample integrity, ideal for on-site food quality assessment. The review highlights the advancements in chromatographic techniques, particularly Ultra-high-performance Liquid Chromatography (UHPLC) coupled with modern detectors, enhancing resolution and speed in anthocyanin analysis. It also emphasizes the growing importance of topical techniques in the food industry for their efficiency and minimal sample preparation. By examining the strengths and limitations of both analytical realms, this article aims to shed light on current challenges and prospective advancements, providing insights into future research directions for improving anthocyanin analysis in foods.

Anxiety symptoms without depression are associated with cognitive control network (CNN) dysfunction: An fNIRS study.

Anxiety is a common psychological disorder associated with other mental disorders, with depression being the most common comorbidity. Few studies have examined the neural mechanisms underlying anxiety after controlling for depression. This study aimed to explore whether there are differences in cortical activation in anxiety patients with different severities whose depression are normal. In the current study, depression levels were normal for 366 subjects-139 healthy subjects, 117 with mild anxiety, and 110 with major anxiety. Using the Hospital Anxiety and Depression Scale (HADS) and a verbal fluency task (VFT) to test subjects' anxiety and depression and cognitive function, respectively. A 53-channel guided near-infrared spectroscopic imaging technology (fNIRS) detected the concentration of oxyhemoglobin (oxy-Hb). Correlation analysis between anxiety severity and oxy-Hb concentration in the brain cortex was performed, as well as ANOVA analysis of oxy-Hb concentration among the three anxiety severity groups. The results showed that anxiety severity was significantly and negatively correlated with oxy-Hb concentrations in the left frontal eye field (lFEF) and in the right dorsolateral prefrontal area (rDLPFC). The oxy-Hb concentration in the lFEF and the rDLPFC were significantly lower in the major anxiety disorder group than that in the control group. This suggests that decreased cortical activity of the lFEF and rDLPFC may be neural markers of anxiety symptoms after controlling for depression. Anxiety symptoms without depression may be result from the dysfunction of the cognitive control network (CCN) which includes the lFEF and rDLPFC.

Greater up-modulation of intra-individual brain signal variability makes a high-load cognitive task more arduous for older adults

The extent to which brain responses are less distinctive across varying cognitive loads in older adults is referred to as neural dedifferentiation. Moment-to-moment brain signal variability, an emerging indicator, reveals not only the adaptability of an individual's brain as an inter-individual trait, but also the allocation of neural resources within an individual due to ever-changing task demands, thus shedding novel insight into the process of neural dedifferentiation. However, how the modulation of intra-individual brain signal variability reflects behavioral differences related to cognitively demanding tasks remains unclear. In this study, we employed functional near-infrared spectroscopy (fNIRS) imaging to capture the variability of brain signals, which was quantified by the standard deviation, during both the resting state and an n-back task (n = 1, 2, 3) in 57 healthy older adults. Using multivariate Partial Least Squares (PLS) analysis, we found that fNIRS signal variability increased from the resting state to the task and increased with working memory load in older adults. We further confirmed that greater fNIRS signal variability generally supported faster and more stable response time in the 2- and 3-back conditions. However, the intra-individual level analysis showed that the greater the up-modulation in fNIRS signal variability with cognitive loads, the more its accuracy decreases and mean response time increases, suggesting that a greater intra-individual brain signal variability up-modulation may reflect decreased efficiency in neural information processing. Taken together, our findings offer new insights into the nature of brain signal variability, suggesting that inter- and intra-individual brain signal variability may index distinct theoretical constructs.

Multispectral near-infrared spectroscopy study evaluating the effect of razor design on shaving-induced erythema.

While shaving-induced erythema is a common inflammatory skin issue, there is a lack of quantitative information on how well a shaving product performs in this regard. In this study, multispectral near-infrared spectroscopy (NIRS) imaging was used to quantitatively and qualitatively measure the extent of shaving-induced erythema. The research compares a safety razor and a cartridge razor to evaluate their impact on skin irritation. Fifty-nine healthy male volunteers without pre-existing skin conditions were enrolled. Basic demographics were recorded, and participants' faces or necks were imaged before shaving. Shaving was conducted on the right side of the face/neck with the safety razor and on the left side of the face/neck using the 3-blade cartridge razor. Images were captured immediately after shaving, at 5 and 10 min post-shaving. Tissue oxygen saturation (StO2) measurements demonstrated that the safety razor induced significantly less erythema than the cartridge razor. Immediately after shaving, 40.3% of skin shaved with the safety razor had erythema compared to 57.6% for the cartridge razor. At 5 min post-shaving, 36.5% of skin shaved with the safety razor had erythema, compared to 53.8% of cartridge razor. Multispectral NIRS revealed significant differences in shaving-induced erythema between safety and cartridge razors. Safety razors demonstrated a lower incidence of erythema, suggesting a potential advantage for individuals prone to skin irritation. This study contributes valuable insights into skin irritation and highlights the potential of multispectral NIRS in dermatology research.

Attentional bias to threat is modulated by stimulus content: an fNIRS study.

People are evolutionarily predisposed to associate threat relevant stimuli with fear or aversiveness and show an attentional bias toward threat. Attentional bias modification (ABM) has been shown to reduce threat biases, while quantitative reviews assessing the effectiveness of bias modification yielded inconsistent results. The current study examined the relationship between the training effect of attentional bias to threat and the type of threatening stimuli. Twenty-two participants performed a modified dot-probe task while undergoing functional near-infrared spectroscopy (fNIRS) imaging. Results indicated that there was a strong pattern of attentional avoidance among individuals in an animal but not human threat condition. Furthermore, findings from fNIRS confirmed that the influence from type of threatening stimulus would be modulated by cortical activation patterns, especially in the ventrolateral prefrontal cortices (vlPFC) and angular gyrus. Overall, these results suggest that stimulus-specific may play a major role in personalization of specific psychological interventions.

Effect of chronic kidney disease induced calcification on peripheral vascular perfusion using near-infrared spectroscopic imaging.

Low-cost techniques that can detect the presence of vascular calcification (VC) in chronic kidney disease (CKD) patients could improve clinical outcomes. In this study, we established a near-infrared spectroscopy-based imaging technique to determine changes in peripheral hemodynamics due to CKD-induced VC. Mice were fed a high-adenine diet with either normal or high levels of phosphate to induce CKD with and without VC, respectively. The mice tail was imaged to evaluate hemodynamic changes in response to occlusion. The rate of change in oxyhemoglobin in response to occlusion showed a statistically significant difference in the presence of VC in the mice.

Spectroscopy, a Tool for the Non-Destructive Sensory Analysis of Plant-Based Foods and Beverages: A Comprehensive Review

In recent years, there has been a significant rise in the popularity of plant-based products due to various reasons, such as ethical concerns, environmental sustainability, and health benefits. Sensory analysis is a powerful tool for evaluating the human appreciation of food and drink products. To link the sensory evaluation to the chemical and textural compositions, further quantitative analyses are required. Unfortunately, due to the destructive nature of sensory analysis techniques, quantitative evaluation can only be performed on samples that are different from those ingested. The quantitative knowledge of the analytical parameters of the exact sample ingested would be far more informative. Coupling non-destructive techniques, such as near-infrared (NIR) and hyperspectral imaging (HSI) spectroscopy, to sensory evaluation presents several advantages. The intact sample can be analyzed before ingestion, providing in a short amount of time matrices of quantitative data of several parameters at once. In this review, NIR and imaging-based techniques coupled with chemometrics based on artificial intelligence and machine learning for sensory evaluation are documented. To date, no review article covering the application of these non-destructive techniques to sensory analysis following a reproducible protocol has been published. This paper provides an objective and comprehensive overview of the current applications of spectroscopic and sensory analyses based on the state-of-the-art literature from 2000 to 2023.

Effect of the VR-guided grasping task on the brain functional network.

Virtual reality (VR) technology has been demonstrated to be effective in rehabilitation training with the assistance of VR games, but its impact on brain functional networks remains unclear. In this study, we used functional near-infrared spectroscopy imaging to examine the brain hemodynamic signals from 18 healthy participants during rest and grasping tasks with and without VR game intervention. We calculated and compared the graph theory-based topological properties of the brain networks using phase locking values (PLV). The results revealed significant differences in the brain network properties when VR games were introduced compared to the resting state. Specifically, for the VR-guided grasping task, the modularity of the brain network was significantly higher than the resting state, and the average clustering coefficient of the motor cortex was significantly lower compared to that of the resting state and the simple grasping task. Correlation analyses showed that a higher clustering coefficient, local efficiency, and modularity were associated with better game performance during VR game participation. This study demonstrates that a VR game task intervention can better modulate the brain functional network compared to simple grasping movements and may be more beneficial for the recovery of grasping abilities in post-stroke patients with hand paralysis.

The Application of Handheld Near-Infrared Spectroscopy and Raman Spectroscopic Imaging for the Identification and Quality Control of Food Products.

The following investigations describe the potential of handheld NIR spectroscopy and Raman imaging measurements for the identification and authentication of food products. On the one hand, during the last decade, handheld NIR spectroscopy has made the greatest progress among vibrational spectroscopic methods in terms of miniaturization and price/performance ratio, and on the other hand, the Raman spectroscopic imaging method can achieve the best lateral resolution when examining the heterogeneous composition of samples. The utilization of both methods is further enhanced via the combination with chemometric evaluation methods with respect to the detection, identification, and discrimination of illegal counterfeiting of food products. To demonstrate the solution to practical problems with these two spectroscopic techniques, the results of our recent investigations obtained for various industrial processes and customer-relevant product examples have been discussed in this article. Specifically, the monitoring of food extraction processes (e.g., ethanol extraction of clove and water extraction of wolfberry) and the identification of food quality (e.g., differentiation of cocoa nibs and cocoa beans) via handheld NIR spectroscopy, and the detection and quantification of adulterations in powdered dairy products via Raman imaging were outlined in some detail. Although the present work only demonstrates exemplary product and process examples, the applications provide a balanced overview of materials with different physical properties and manufacturing processes in order to be able to derive modified applications for other products or production processes.

Utilization of Near Infrared Spectroscopy Imaging at Nanoscale for the Identification of Biomarkers in Sports-Induced Muscle Fatigue

This study integrates Near Infrared Spectroscopy (NIRS) and nanoscale imaging technologies to discern alterations in muscle tissue biomarkers, thereby enhancing the precision of non-invasive monitoring of muscle fatigue. Experimental investigations were carried out on the biceps brachii muscle of 12 subjects, categorized into mild, moderate, and severe fatigue groups. Concurrently, a specific wavelength of Near Infrared Laser Diode (NIR-LD) was employed to acquire spectral data. The application of Atomic Force Microscopy (AFM) in conjunction with NIRS imaging facilitated the attainment of high-resolution images of the biceps brachii tissue. The absorption characteristics of distinct biomarkers in muscle tissue, responsive to near-infrared light, were captured to calculate concentration variations and evaluate muscle fatigue levels. The findings revealed substantial variations in the concentrations of Oxy-hemoglobin (HbO), Deoxy-hemoglobin (HbR), Lactic Acid (LA), Phosphocreatine (PCr), Troponin (Tn), Creatine Kinase (CK), and Glutamine (Gln) across different fatigue groups. Muscle fatigue assessment exhibited an average sensitivity, accuracy, specificity, and F1 score of 0.96, 0.96, 0.95, and 0.96, respectively, for the 12 subjects. The average Area Under the Curve (AUC) values for detecting mild, moderate, and severe fatigue were 0.96, 0.96, and 0.98, respectively. This method demonstrates notable accuracy in the identification of muscle fatigue biomarkers, rendering it suitable for sports-related muscle fatigue assessment.

Optical Imaging in Human Lymph Node Specimens for Detecting Breast Cancer Metastases: A Review.

Assessment of regional lymph node status in breast cancer is of important staging and prognostic value. Even though formal histological examination is the currently accepted standard of care, optical imaging techniques have shown promising results in disease diagnosis. In the present article, we review six spectroscopic techniques and focus on their use as alternative tools for breast cancer lymph node assessment. Elastic scattering spectroscopy (ESS) seems to offer a simple, cost-effective, and reproducible method for intraoperative diagnosis of breast cancer lymph node metastasis. Optical coherence tomography (OCT) provides high-resolution tissue scanning, along with a short data acquisition time. However, it is relatively costly and experimentally complex. Raman spectroscopy proves to be a highly accurate method for the identification of malignant axillary lymph nodes, and it has been further validated in the setting of head and neck cancers. Still, it remains time-consuming. Near-infrared fluorescence imaging (NIRF) and diffuse reflectance spectroscopy (DFS) are related to significant advantages, such as deep tissue penetration and efficiency. Fourier-transform infrared spectroscopy (FTIR) is a promising method but has significant drawbacks. Nonetheless, only anecdotal reports exist on their clinical use for cancerous lymph node detection. Our results indicate that optical imaging methods can create informative and rapid tools to effectively guide surgical decision-making.

Characterization of lipidic coronary atheroma under control of low-density lipoprotein &amp;lt;1.8 mmol/l and lipoprotein (a) &amp;lt;50 mg/dl in patients with coronary artery disease

Abstract Background Lp(a) has been considered as a potential therapeutic target associated with atherosclerosis. In particular, Lp(a) ≧50 mg/dL has been shown to predict an elevated cardiovascular risk even under lowering LDL-C level, indicating that lowering of both LDL-C and Lp(a) may be more beneficial to halt atherogenesis. However, atherosclerotic features with favorable control of these lipid targets have not been fully characterized yet. The REASSURE-NIRS registry (NCT04864171) is an on-going multi-center registry which enrolls CAD patients receiving near-infrared spectroscopy (NIRS)/IVUS-guided PCI in Japan. Given that NIRS enables to quantitatively evaluate lipidic plaque materials, this registry provides an opportunity to investigate lipidic plaque features in association with LDL-C and Lp(a) levels. Objectives The aim of this study was to elucidate NIRS-derived characteristics of coronary atheroma in patients with CAD who exhibited both LDL-C&amp;lt;1.8 mmol/L and Lp(a) &amp;lt;50 mg/dL. Methods From the REASSURE-NIRS registry (n=1013), we investigated 549 culprit lesions in 498 patients with measurement of both LDL-C and Lp(a) levels at the index of PCI. Maximum 4-mm lipid core burden index (max LCBI4mm) at culprit lesions were measured with NIRS imaging prior to PCI. Study subjects were stratified into 4 groups according to LDL-C and Lp(a) levels: LDL-C&amp;lt;1.8mmol/L and Lp(a)&amp;lt;50mg/dL, LDL-C≧1.8mmol/ and Lp(a)&amp;lt;50mg/dL, LDL-C&amp;lt;1.8mmol/L and Lp(a)≧50mg/dL, LDL-C≧1.8mmol/L and Lp(a)≧50mg/dL. Clinical characteristics and max LCBI4mm were compared in 4 groups. Results In the current study, 30.6% of patients was ACS. Under the use of lipid-lowering therapies (statin: 68.4% and high-intensity statin: 26.0%), 33.1% of study population exhibited both LDL-C&amp;lt;1.8mmol/L and Lp(a)&amp;lt;50mg/dL. Patients with LDL-C&amp;lt;1.8mmol/L and Lp(a)&amp;lt;50mg/dL were more likely to be male (p=0.002) and smoker (p=0.002) and have a history of previous MI (p&amp;lt;0.001). As expected, statin was more frequently used in those with both LDL-C&amp;lt;1.8mmol/L and Lp(a)&amp;lt;50mg/dL (p&amp;lt;0.001). On NIRS imaging analysis, patients with low LDL-C&amp;lt;1.8mmol/L and Lp(a)&amp;lt;50mg/dL were associated with significantly lower max LCBI4mm (Figure). Of note, even in patients with LDL-C&amp;lt;1.8mmol/L, max LCBI4mm was lower in those achieving Lp(a) &amp;lt;50 mg/dL compared to those with Lp(a) ≧50 mg/dL (p=0.001). Multivariate analysis adjusting for ACS, LDL-C levels and statin use, Lp(a) levels revealed emerged as independent predictor of maxLCBI4mm (β=1.0, 95%CI: 0.06 to 2.04, p=0.04). Conclusion Patients with LDL-C&amp;lt;1.8mmol/L and Lp(a)&amp;lt;50mg/dL more likely exhibited a smaller amount of lipidic plaque materials on NIRS imaging. Our findings support that lowering both LDL-C and Lp(a) may be more beneficial to modulate lipidic plaque component, which ultimately results in the further reduction of ASCVD risks.Comparison of clinical characteristics

Lipid core burden in relation to the severity of calcium burden assessed by computed tomographic coronary angiography in patients with chronic coronary syndrome

Abstract Background Coronary calcium scores (CACS) obtained by computed tomographic coronary angiography (CTCA) enables a noninvasive assessment of coronary calcium burden both in a single vessel and in whole coronary tree. Although higher CACS in coronary tree is known as an atherosclerotic cardiovascular disease risk marker, coronary calcification is also known as a sign of plaque stabilization. Exploring the relationship between coronary calcification and lipid core burden may help understanding a role of calcium in coronary tree. Purpose We aimed to examine the relevance of lipid components assessed by near-infrared spectroscopy (NIRS) in accordance with different degrees of CACS assessed by preprocedural CTCA imaging. Methods We investigated consecutive patients who underwent elective percutaneous coronary intervention (PCI) and pre-PCI CTCA imaged within 3 months before PCI. Patients who had stents in target vessels and who required plaque modification before NIRS imaging were excluded. Target vessels were divided into tertiles based on target vessel CACS (CACSv) and total amount of 3-vessel CACS (CACSt), respectively. Lipid components of the target vessel were evaluated by maximum lipid core burden index in 4mm (maxLCBI4mm). MaxLCBI4mm was compared among the tertiles of CACSv and CACSt. Results A total of 95 target vessels in 95 patients were evaluated for the final dataset. CACSv categories were defined as follows: 1st tertile (CACSv &amp;lt;66), 2nd tertile (CACSv &amp;gt;66 and &amp;lt;250), and 3rd tertile (CACSv &amp;gt;250). CACSt categories were defined as showing CACSt &amp;lt;190 (1st tertile), CACSt &amp;gt;190 and &amp;lt;700 (2nd tertile), and CACSt &amp;gt;700 (3rd tertile). MaxLCBI4mm increased in proportion to an extent of CACv tertiles (306 [129-463], 280 [125-460], and 444 [345-587], Ptrend &amp;lt;0.01) and an extent of CACt tertiles (265 [99-488], 356 [202-458], and 448 [318-574], Ptrend &amp;lt;0.01). Conclusions In patients who underwent elective PCI, higher maxLCBI4mm in the PCI target vessel was associated with both higher CACS in the target vessel and total amount of 3-vessel CACS.

Predictors of residual lipid content detected by near-infrared spectroscopy after elective stenting in patients with chronic coronary syndrome

Abstract Backgrounds Residual lipid-rich plaque (LRP) in stented segments assessed by near-infrared spectroscopy (NIRS) immediately after percutaneous coronary intervention (PCI) is reportedly associated with target lesion failure. However, morphological determinants of residual LRP after elective PCI remains unknown. Purpose This single-center observational study aimed to explore morphological and procedural predictors of residual LRP after electing PCI. Methods We investigated 340 consecutive patients who underwent elective NIRS-intravascular ultrasound-guided PCI for de novo coronary lesions. Lesions requiring balloon dilatation or debulking before NIRS imaging, requiring ≥2 remote stent deployment in the vessel, being treated with drug-coated balloon, and having insufficient NIRS imaging were excluded. Maximum lipid core burden index in 4mm (maxLCBI4mm) in culprit segment both before and after PCI was assessed by NIRS. Residual LRP was defined as post-PCI maxLCBI4mm in stented lesions &amp;gt;200. Baseline clinical and morphological findings were compared between lesions with versus without residual LRP. Multivariable logistic regression analysis was performed to determine predictors of residual LRP. Results A total of 236 de novo lesions in 223 patients were included in the final dataset. After PCI, residual LRP was observed in 69 (29%) lesions. Patients with residual LRP tended to be older than those without residual LRP. Pre-PCI maxLCBI4mm in culprit lesions, plaque burden, and remodeling index were greater in lesions with residual LRP. Post-PCI minimum stent area and expansion index tended to be smaller in lesions with residual LRP. In a multivariable analysis, pre-PCI maxLCBI4mm (per 10, adjusted odds ratio [OR]:1.04; 95% confidence interval [CI]: 1.02 to 1.05; p&amp;lt;0.01) and stent expansion index (per 10%, adjusted OR: 0.80; 95%CI: 0.64 to 0.99; p=0.047) were independently predictive of residual LRP. Conclusions In patients undergoing elective PCI, greater pre-PCI maxLCBI4mm and smaller stent expansion were associated with post-PCI residual LRP.

Computed tomographic predictors of a lipid-rich plaque identified by near-infrared spectroscopy

Abstract Background In a phase of primary prevention, individuals with high coronary calcium scores (CACS) assessed by computed tomographic coronary angiography (CTCA) are known to be associated with higher risk of atherosclerotic cardiovascular disease. However, clinical significance of CACS in patients requiring revascularization and its relevance to lipid core burden remains unknown. Purpose This study aimed to examine the relationship between lipid components assessed by near-infrared spectroscopy (NIRS) and coronary artery calcium score (CACS) assessed by preprocedural CTCA imaging. We also aimed to investigate CTCA-derived predictors of target vessels with high lipid core burden. Methods Consecutive patients who underwent preprocedural CTCA imaged within 3 months before elective NIRS-intravascular ultrasound-guided percutaneous coronary intervention (PCI) for de novo lesions in 1 coronary artery were included. Patients who had undergone stent deployment before inclusion were excluded. Target vessels requiring lesion modification such as balloon inflation or debulking before NIRS imaging were also excluded. Lipid rich plaque (LRP) was defined as a target lesion with maximum LCBI in 4 mm (maxLCBI4mm) &amp;gt;500. Clinical demographics, angiographic, and CTCA-derived morphological findings were compared between target vessels with and without LRP. Results A total of 95 target vessels in 95 patients were evaluated for the final dataset. NIRS identified 25 LRP and 70 non-LRP. Clinical demographics and angiographic findings showed no significant differences between vessels with versus without LRP. On CTCA, prevalence of high-risk plaque (HRP) that contains two or more of napkin-ring sign, positive remodeling, low attenuation plaque and spotty calcification at the target vessel was significantly higher in LRP group (56.0 % vs. 25.7 %, P=0.01). Target vessel CACS and total amount of 3-vessel CACS tended to be higher in patients with LRP than those without LRP (282 [124-479] vs. 114 [25-248], P=0.01; 882 [233-1501] vs. 308 [99-753], P=0.01, respectively). Multivariate logistic regression analyses to predict LRP at the target vessel revealed that the presence of HRP (odds ratio [OR] 3.52, 95% confidence interval [CI] 1.28-9.69, P=0.01) and higher 3-vessel CACS (per 100, OR 1.09, 95% CI 1.03-1.16, P &amp;lt;0.01) were independently predictive of LRP. Conclusions Preprocedural CTCA-derived high-risk plaque and total amount of 3-vessel CACS were independent predictors of LRP defined by NIRS.

Incremental value of physiological indices to predict high-risk plaque detected by NIRS-IVUS

Abstract Background The vulnerable plaque are called high-risk plaques (HRPs), and coronary computed tomography angiography (CCTA) studies have revealed the following characteristics: (1) lesion plaque density on CT≦30HU (2) positive remodeling, (3) The presence of spotty calcification, (4) ΔFractional Flow Reserve derived from CCTA (FFRCT) or Δ Quantitative Flow Reserve (QFR)≧0.06 has been cited as a feature of these lesions. Therefore, identification of HRPs in non-culprit lesion is important to reduce future cardiovascular events. Purpose The purpose of the study was to determine whether HRP is predictable by incremental values of physiological indices in non-culprit lesions of ACS subjects. Methods A total of 137 non-culprit coronary lesions in 31 ACS subjects were retrospectively evaluated by CCTA, FFRCT, QFR and NIRS-IVUS imaging. Each coronary artery was divided into 30mm long segments beginning at the ostium to evaluate lesion vulnerability. By NIRS imaging, plaque with 4-mm maximum lipid-core burden index (maxLCBI4mm) ≥400 was defined as HRP. The relationship between HRP detected by NIRS and CCTA-derived plaque features, delta (Δ) FFRCT, and ΔQFR was evaluated. Results CT density, positive remodeling, diameter stenosis, ΔFFRCT, and ΔQFR were significantly associated with HRP, respectively (P&amp;lt;0.05). On multivariable analysis, CT density (OR; 0.95, 95%CI 0.91-0.99, P=0.0001), diameter stenosis (OR; 1.05, 95%CI 1.00-1.10, P=0.03) and ΔQFR (OR; 2119483 , 95%CI 1.75-2561856632475.6, P=0.03) independently predicted HRP, but not ΔFFRCT. ROC analysis for predicting HRP showed greater accuracy with incremental ΔQFR values in the model of CT density and diameter stenosis (AUC 0.93, P&amp;lt;0.0001). Conclusion HRP detected by NIRS may be predicted with greater accuracy by integrating QFR values with the assessment of CCTA-derived plaque features.figure1figure2

Abstract 16462: Phenotypic Features of Lipidic Plaque in Patients With Polyvascular Disease: Findings From the Reassure Near-Infrared Spectroscopy Imaging Multi-Center Registry

Introduction: Polyvascular disease (PolyVD) is a high-risk atherosclerotic phenotype presenting worse cardiovascular outcomes. However, its atherosclerotic features remain to be fully elucidated yet. Near-infrared spectroscopy (NIRS) imaging quantifies lipidic plaque associated with clinical outcome. Hypothesis: Given a clustering of atherogenic risks in PolyVD, PolyVD may exhibit a distinct plaque phenotype, which accounts for their outcome. Methods: 224 culprit lesions in 203 CAD patients receiving PCI were evaluated by NIRS imaging. PolyVD was defined as those with additional ASCVD (stroke and/or LEAD). NIRS-derived lipidic plaque feature (maxLCBI 4mm ) and clinical outcome (all-cause death+non-fatal MI+stroke) were compared in PolyVD and non-PolyVD subjects. Results: 28.6% of study subjects exhibited PolyVD. They were older (77 v. 71 years, p=0.02) with a greater frequency of CKD (61 v. 45%, p=0.03). Under the use of statin (81 v. 71%, p=0.15) and ezetimibe (32 v. 21%, p=0.09), PolyVD patients had a lower LDL-C level (73 v. 84 mg/dL, p=0.01). Despite their LDL-C control, maxLCBI 4mm did not differ in two groups (median: 458 v. 576, p=0.19). Moreover, 64% of PolyVD patients still showed maxLCBI 4mm ≧400 (69% in non-PolyVD, p=0.44). On multivariate analysis, ACS independently predicted maxLCBI 4mm ≧400 (Figure) in PolyVD patients. Of note, PolyVD presenting ACS had a higher maxLCBI 4mm (790 v. 411, p=0.001) compared to those without ACS, whereas this relationship did not exist in non-PolyVD (622 v. 561, p=0.19, Figure). During the 3-year observational period, PolyVD was associated with an elevated risk of MACE (p=0.002). Conclusions: Despite lowering LDL-C levels, PolyVD harbored a large amount of lipidic materials, accompanied by worse cardiovascular outcomes. Given the relationship of ACS with maxLCBI 4mm in PolyVD, additional therapies which modulates ACS-related inflammatory activity may be warranted to alter their disease substrate and outcomes.

Near-infrared spectroscopy with a provocative maneuver to detect the presence of severe peripheral arterial disease

Current assessment standards for peripheral arterial disease (PAD), such as the ankle brachial index, are limited in their utility and portability. Near-infrared spectroscopy (NIRS) has shown some promise in diagnosing PAD when used in conjunction with a provocative maneuver. The purpose of this study was to assess the viability of NIRS in conjunction with a transient leg elevation provocative maneuver for detecting severe PAD. This retrospective observational cross-sectional study assessed 57 limbs in 34 patients receiving routine vascular screening for PAD at Madigan Army Medical Center. The patient limbs were stratified into normal (n = 17), mild (n = 9), moderate (n = 16), and severe (n = 15) PAD groups based on the clinician assessments. Additionally, the patients were assessed with NIRS measurements taken with the patient in the supine position at rest and using a provocative leg raise maneuver of transient leg elevation of 45° for 60 seconds. The resting tissue oxygen saturation (StO2) and the change in StO2 (ΔStO2) from rest to elevation were recorded and compared between the PAD severity groups via independent measures analysis of variance with the Tukey honest significant difference post hoc test. The supine resting StO2 was not different between the normal (77.5% ± 7.7%), mild (72.5% ± 7.4%), moderate (72.0% ± 10.3%), and severe (74.2% ± 5.4%) PAD groups (P = .23). However, the ΔStO2 with transient leg elevation was significantly greater in the severe PAD group (−17.2% ± 6.0%) compared with the normal (−3.9% ± 4.8%), mild (−6.9% ± 4.7%), and moderate (−9.7% ± 5.2%) PAD groups (P < .002 for all). Similar results were observed in the changes in oxyhemoglobin and deoxyhemoglobin. The leg elevation protocol was also used for two patients before and after lower limb revascularization, which demonstrated that the ΔStO2 corresponded with the clinical assessment of PAD severity. Resting supine NIRS images were unable to detect any differences among normal and limbs with different PAD severity. However, NIRS imaging with 45° leg elevation for 60 seconds showed a significant difference between severe PAD compared healthy patients and those with mild to moderate PAD in a fast, precise, and accurate manner. These preliminary data support the use of NIRS and transient leg elevation as a tool to diagnose severe PAD but do not support the use of NIRS alone as a screening test for PAD. NIRS measurements with leg elevation might be a viable noninvasive, noncontact, and portable method of assessing severe PAD for home monitoring, in rural communities, and/or in standard clinical practice.