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Aims The left anterior descending (LAD) artery is the most frequently affected site by coronary artery disease. The prospective Lipid Rich Plaque (LRP) study, which enrolled patients undergoing imaging of non-culprits followed over 2 years, reported the successful identification of coronary segments at risk of future events based on near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) lipid signals. We aimed to characterize the plaque events involving the LAD vs. non-LAD segments. Methods and results LRP enrolled 1563 patients from 2014 to 2016. All adjudicated plaque events defined by the composite of cardiac death, cardiac arrest, non-fatal myocardial infarction, acute coronary syndrome, revascularization by coronary bypass or percutaneous coronary intervention, and rehospitalization for angina with >20% stenosis progression and reported as non-culprit lesion-related major adverse cardiac events (NC-MACE) were classified by NIRS-IVUS maxLCBI4 mm (maximum 4-mm Lipid Core Burden Index) ≤400 or >400 and association with high-risk-plaque characteristics, plaque burden ≥70%, and minimum lumen area (MLA) ≤4 mm2. Fifty-seven events were recorded with more lipid-rich plaques in the LAD vs. left circumflex and right coronary artery; 12.5% vs. 10.4% vs. 11.3%, P  = 0.097. Unequivocally, a maxLCBI4 mm >400 in the LAD was more predictive of NC-MACE [hazard ratio (HR) 4.32, 95% confidence interval (CI) (1.93–9.69); P  = 0.0004] vs. [HR 2.56, 95% CI (1.06–6.17); P  = 0.0354] in non-LAD segments. MLA ≤4 mm2 within the maxLCBI4 mm was significantly higher in the LAD (34.1% vs. 25.9% vs. 13.7%, P  < 0.001). Conclusion Non-culprit lipid-rich segments in the LAD were more frequently associated with plaque-level events. LAD NIRS-IVUS screening may help identify patients requiring intensive surveillance and medical treatment. [ABSTRACT FROM AUTHOR]

Noninvasive detection of surface-enhanced Raman spectroscopy (SERS) signals from deep within tissue represents a common challenge in many biological and clinical applications including disease diagnosis and therapy monitoring. Such signals are typically weak and not readily discernible from often much larger Raman and fluorescence background signals (e.g., from surrounding tissue). Consequently, suboptimal sensitivity in the detection of SERS signals is often achieved in these situations. Similar issues can arise in SERS measurements in other diffusely scattering samples and complex matrices. Here, we propose a novel concept, active SERS, for the efficient retrieval of SERS signals from deep within complex matrices such as biological tissues that mitigates these issues. It relies on applying an external perturbation to the sample to alter the SERS signal from nanoparticles (NPs) deep inside the matrix. A measurement with and without, or before and after, such perturbation then can provide powerful contrasting data enabling an effective elimination of the matrix signals to reveal more clearly the desired SERS signal without the interfering background and associated artifacts. The concept is demonstrated using ultrasound (US) as an external source of perturbation and SERS NPs inserted deep within a heterogeneous tissue phantom mimicking a cluster of NPs accumulated within a small target lesion. The overall SERS signal intensity induced by the applied US perturbation decreased by ∼21% and the SERS signal contrast was considerably improved by eliminating subtraction artifacts present in a conventional measurement performed at a neighboring spatial location in a heterogeneous tissue sample. Although the technique was demonstrated with SERS gold NPs with a standard Raman label, it is envisaged that active SERS NPs (both the nanoscale metal geometry and Raman label) could be specifically designed to deliver an augmented response to the external stimulus to further enhance the achievable SERS signal contrast and yield even greater improvement in detection sensitivity. The method was demonstrated using transmission Raman spectroscopy; however, it is also applicable to other Raman implementations including spatially offset Raman spectroscopy and conventional Raman spectroscopy performed both at depth and at surfaces of complex matrices. [ABSTRACT FROM AUTHOR]

Aims: The left anterior descending (LAD) artery is the most frequently affected site by coronary artery disease. The prospective Lipid Rich Plaque (LRP) study, which enrolled patients undergoing imaging of non-culprits followed over 2 years, reported the successful identification of coronary segments at risk of future events based on near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) lipid signals. We aimed to characterize the plaque events involving the LAD vs. non-LAD segments., Methods and Results: LRP enrolled 1563 patients from 2014 to 2016. All adjudicated plaque events defined by the composite of cardiac death, cardiac arrest, non-fatal myocardial infarction, acute coronary syndrome, revascularization by coronary bypass or percutaneous coronary intervention, and rehospitalization for angina with >20% stenosis progression and reported as non-culprit lesion-related major adverse cardiac events (NC-MACE) were classified by NIRS-IVUS maxLCBI4 mm (maximum 4-mm Lipid Core Burden Index) ≤400 or >400 and association with high-risk-plaque characteristics, plaque burden ≥70%, and minimum lumen area (MLA) ≤4 mm2. Fifty-seven events were recorded with more lipid-rich plaques in the LAD vs. left circumflex and right coronary artery; 12.5% vs. 10.4% vs. 11.3%, P = 0.097. Unequivocally, a maxLCBI4 mm >400 in the LAD was more predictive of NC-MACE [hazard ratio (HR) 4.32, 95% confidence interval (CI) (1.93-9.69); P = 0.0004] vs. [HR 2.56, 95% CI (1.06-6.17); P = 0.0354] in non-LAD segments. MLA ≤4 mm2 within the maxLCBI4 mm was significantly higher in the LAD (34.1% vs. 25.9% vs. 13.7%, P < 0.001)., Conclusion: Non-culprit lipid-rich segments in the LAD were more frequently associated with plaque-level events. LAD NIRS-IVUS screening may help identify patients requiring intensive surveillance and medical treatment., Competing Interests: Conflict of interest: R.W., C.D.M., H.M.G.-G., and R.T. were Principal Investigator, European Principal Investigator, Responsible Officer Core Laboratory NIRS-IVUS and angiographic analysis, Worldwide Study Coordinator of the Lipid Rich Trial, sponsored by Infraredx-Nipro, Bedford, MA, USA. H.M.G.-G. reports the following institutional grant support: Biotronik, Boston Scientific, Medtronic, Abbott, Neovasc, Shockwave, Phillips, and Corflow. C.D.M. is the recipient of research grants (through the Department of Clinical and Experimental Medicine of the University of Florence) from AMGEN, Behring, Chiesi, Daiichi Sankyo, Edwards, Medtronic, and Shockwave. Z.A.A. reports grants from NIH/NHLBI, Abbott Vascular, and Cardiovascular Systems Inc.; personal fees from Amgen, Astra Zeneca, and Boston Scientific; and equity from Shockwave Medical. G.S.M. reports honoraria from Boston Scientific and Philips. R.W. reports serving on the advisory boards of Abbott Vascular, Amgen, Boston Scientific, Cardioset, Cardiovascular Systems Inc., Medtronic, Philips, and Pi-Cardia Ltd.; being a consultant for Abbott Vascular, Amgen, Biotronik, Boston Scientific, Cardioset, Cardiovascular Systems Inc., Medtronic, Philips, Pi-Cardia Ltd., and Transmural Systems; receiving grant support from AstraZeneca, Biotronik, Boston Scientific, and Chiesi; serving on the speakers bureaus of AstraZeneca and Chiesi, and being an investor in MedAlliance and Transmural Systems. All other authors declared no conflict of interest., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2021. For permissions, please email: journals.permissions@oup.com.)