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Introduction: Non-obstructive coronary arteries (NOCA) are present in 39.7% to 62.4% of patients who undergo elective angiography. Coronary microcirculation (<400 µm) is not visible on angiography therefore functional assessment, invasive or noninvasive plays a prior role to help provide a more personalized diagnosis of angina., Area Covered: In this review, we revisit the pathophysiology, clinical importance, and invasive assessment of the coronary microcirculation, and discuss angiography-derived indices of microvascular resistance. A comprehensive literature review over four decades is also undertaken., Expert Opinion: The coronary microvasculature plays an important role in flow autoregulation and metabolic regulation. Invasive assessment of microvascular resistance is a validated modality with independent prognostic value, nevertheless, its routine application is hampered by the requirement of intravascular instrumentation and hyperemic agents. The angiography-derived index of microvascular resistance has emerged as a promising surrogate in pilot studies, however, more data are needed to validate and compare the diagnostic and prognostic accuracy of different equations as well as to illustrate the relationship between angiography-derived parameters for epicardial coronary arteries and those for the microvasculature.

Aims: Plaque structural stress (PSS) is a major cause of atherosclerotic plaque rupture and major adverse cardiovascular events (MACE). We examined the predictors of changes in peak and mean PSS (ΔPSS peak , ΔPSS mean ) in three studies of patients receiving either standard medical or high-intensity statin (HIS) treatment., Methods and Results: We examined changes in PSS, plaque size, and composition between 7348 co-registered baseline and follow-up virtual-histology intravascular ultrasound images in patients receiving standard medical treatment (controls, n = 18) or HIS (atorvastatin 80 mg, n = 20, or rosuvastatin 40 mg, n = 22). The relationship between changes in PSS peak and plaque burden (PB) differed significantly between HIS and control groups ( P < 0.001). Notably, PSS peak increased significantly in control lesions with PB >60% ( P = 0.04), but not with HIS treatment. However, ΔPSS peak correlated poorly with changes in lumen and plaque area or PB, plaque composition, or lipid lowering. In contrast, ΔPSS peak correlated significantly with changes in lumen curvature, irregularity, and roughness ( P < 0.05), all of which were reduced in HIS patients. ΔPSS mean correlated with changes in lumen area, PA, PB, and circumferential calcification, and was unchanged with either treatment., Conclusion: Our observational study shows that PSS peak changes over time were associated with baseline disease severity and treatment. The PSS peak increase seen in advanced lesions with standard treatment was associated with remodelling artery geometry and plaque architecture, but this was not seen after HIS treatment. Smoothing plaques by reducing plaque/lumen roughness, irregularity, and curvature represents a novel mechanism whereby HIS may reduce PSS and, thus may protect against plaque rupture and MACE., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: Disparities between weekend and weekday care, termed 'the weekend effect', have led to a UK government pledge to provide 7-day services. Despite this, poor outcomes have led to criticism of the programme. This study consequently sought to evaluate consultant-led virtual review as a model for 7-day cardiology services., Methods: Over 4 weekends, cardiology patients underwent virtual review alongside in-person teams. Outcomes included length of stay, same-day discharge and 30-day mortality rates, as well as duration of ward rounds and change in patient management. Patients were surveyed on attitudes towards virtual review., Results: Statistical analysis revealed no significant difference in clinical outcomes, while virtual review was noted to significantly decrease time taken (p<0.0001). Attitudes towards virtual review were broadly favourable., Conclusion: By demonstrating comparable outcomes compared with conventional review, as well as high acceptability, this study identified virtual review as an effective substitute for in-person care., (© Royal College of Physicians 2021. All rights reserved.)

Introduction: Areas covered:In this review, we outline the underlying causes of acute coronary syndrome (ACS) as evaluated by optical coherence tomography (OCT). We report both the definitions of each mechanism and its frequency as reported in the literature to date. Finally, we present an algorithm based on the findings in the review that gives an outlined approach to perform intervention on ACS patients.Expert opinion:Although the most common and most accepted intervention in ACS cases is stent implantation, data suggest a stentless approach in cases of plaque erosion, which generally occurs in younger patients presenting with an acute coronary syndrome that have TIMI flow of 2/3 and either a small or large burden of thrombus and underlying stenosis of less than 50%.

Objective: We aimed to assess the use of enhanced stent visualisation (ESV) on outcomes, after PCI with overlapping stents, specifically using CLEARstent technology., Background: Stent underexpansion and overlap are both significant risk factors for restenosis and stent thrombosis. Enhanced stent visualisation (e.g. CLEARstent) systems could provide important data to reduce under-expansion and stent overlap., Methods: This was a cohort study based on this institution's percutaneous coronary intervention (PCI) registry. A total of 2614 patients who had PCI for stable angina or acute coronary syndromes (ACS, excluding cardiogenic shock) with overlapping 2nd generation drug eluting stents (DES) in the same vessel between May 2015 and January 2018 were included in the analysis. Patients were divided into ESV (n = 1354) and no ESV guided intervention (n = 1260). The primary end-point was major adverse cardiovascular events (MACE: target vessel revascularisation, target vessel myocardial infarction and all-cause mortality) recorded at a median follow up of 2.4 years., Results: Groups were comparable for patient characteristics (age, diabetes mellitus, ACS presentation). A significant difference in MACE was observed between patients who underwent ESV-guided PCI (9.5%) compared with patients who underwent Standard PCI (14.4%, p = .018). This difference was mainly driven by reduced rates of target vessel revascularisation and recurrent myocardial infarction. Overall this difference persisted after multivariate Cox analysis (HR 0.86, 95% CI: 0.73-0.98) and propensity matching (HR = 0.88, 95% CI: 0.69-0.99)., Conclusion: We suggest that routine clinical use of ESV technology during PCI can be useful, and is associated with better medium-term angiographic and clinical outcomes. Further study is required to build on this promising signal., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest to declare., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have been developed and improved as both diagnostic and guidance tools for interventional procedures over the past three decades. IVUS has a resolution of 100 μm with a high tissue penetration and capability of assessing the entire structure of a coronary artery including the external elastic membrane, whereas OCT has a higher resolution of 10-20 μm to assess endoluminal structures with a limited tissue penetration compared to IVUS. Recently, two companies, CONAVI and TERUMO, integrated IVUS and OCT into a single catheter system. With their inherent strength and limitations, the combined IVUS and OCT probes are complementary and work synergistically to enable a comprehensive depiction of coronary artery. In this review, we summarize the performance of the two intracoronary imaging modalities-IVUS and OCT-and discuss the expected potential of the novel hybrid IVUS-OCT catheter system in the clinical field., (Copyright © 2020 Ono, Kawashima, Hara, Gao, Wang, Kogame, Takahashi, Chichareon, Modolo, Tomaniak, Wykrzykowska, Piek, Mori, Courtney, Wijns, Sharif, Bourantas, Onuma and Serruys.)

Non-invasive serial computed tomography coronary angiography (CTCA) was acquired from 32 patients and 3D reconstruction of 58 coronary arteries was achieved. The arterial geometries were utilized for blood flow and LDL transport modelling. Navier-Stokes and convection-diffusion equations were employed for simulation of blood flow and LDL transport, respectively. Disease progression was assessed comparing the follow-up and baseline arterial models after co-registration using side branches as anatomical landmarks. A machine learning model for predicting disease progression was built using the Gradient Boosted Trees (GBT) algorithm. The Accuracy, Sensitivity, Specificity and AUC of the developed methodology for predicting lumen area decrease equal was 0.68, 0.56, 0.34 and 0.59, respectively. The best results were found for the prediction of plaque area increase by 20%, with 0.73, 0.67, 0.86, and 0.76 accuracy, sensitivity, specificity andAUC, respectively. This approach outperforms significantly the predictive capability of models based on binary logistic regression.

Background: Cardiac MR stress perfusion remains a qualitative technique in clinical practice due to technical and postprocessing challenges. However, automated inline perfusion mapping now permits myocardial blood flow (MBF, ml/g/min) quantification on-the-fly without user input., Purpose: To investigate the diagnostic performance of this novel technique in detecting occlusive coronary artery disease (CAD) in patients scheduled to undergo coronary angiography., Study Type: Prospective, observational., Subjects: Fifty patients with suspected CAD and 24 healthy volunteers., Field Strength: 1.5T. SEQUENCE: "Dual" sequence multislice 2D saturation recovery., Assessment: All patients underwent cardiac MR with perfusion mapping and invasive coronary angiography; the healthy volunteers had MR with perfusion mapping alone., Statistical Tests: Comparison between numerical variables was performed using an independent t-test. Receiver operator characteristic (ROC) curves were generated for transmyocardial, endocardial stress MBF, and myocardial perfusion reserve (MPR, the stress:rest MBF ratio) to diagnose severe (>70%) stenoses as measured by 3D quantitative coronary angiography (QCA). ROC curves were compared by the method of DeLong et al. RESULTS: Compared with volunteers, patients had lower stress MBF and MPR even in vessels with <50% stenosis (2.00 vs. 3.08 ml/g/min, respectively). As stenosis severity increased (<50%, 50-70%, >70%), MBF and MPR decreased. To diagnose occlusive (>70%) CAD, endocardial and transmyocardial stress MBF were superior to MPR (area under the curve 0.92 [95% CI 0.86-0.97] vs. 0.90 [95% CI 0.84-0.95] and 0.80 [95% CI 0.72-0.87], respectively). An endocardial threshold of 1.31 ml/g/min provided a per-coronary artery sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 90%, 82%, 50%, and 98%, with a per-patient diagnostic performance of 100%, 66%, 57%, and 100%, respectively., Data Conclusion: Perfusion mapping can diagnose occlusive CAD with high accuracy and, in particular, high sensitivity and NPV make it a potential "rule-out" test., Level of Evidence: 1 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2019;50:756-762., (© 2019 The Authors. Journal of Magnetic Resonance Imaging published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.)

This consensus document is the second of two reports summarizing the views of an expert panel organized by the European Association of Percutaneous Cardiovascular Interventions (EAPCI) on the clinical use of intracoronary imaging including intravascular ultrasound (IVUS), optical coherence tomography (OCT), and near infrared spectroscopy (NIRS)-IVUS. Beyond guidance of stent selection and optimization of deployment, invasive imaging facilitates angiographic interpretation and may guide treatment in acute coronary syndrome. Intravascular imaging can provide additional important diagnostic information when confronted with angiographically ambiguous lesions and allows assessment of plaque morphology enabling identification of vulnerability characteristics. This second document focuses on useful imaging features to identify culprit and vulnerable coronary plaque, which offers the interventional cardiologist guidance on when to adopt an intracoronary imaging-guided approach to the treatment of coronary artery disease and provides an appraisal of intravascular imaging-derived metrics to define the haemodynamic significance of coronary lesions., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

Objectives: The introduction of the bioresorbable vascular scaffold (BVS) has led to new avenues of coronary intervention; however, there have been concerns raised regarding the mechanical properties of BVS and the resulting in-stent thrombosis. We aim to assess whether intracoronary imaging improves outcome in patients following BVS implantation., Patients and Methods: All patients undergoing percutaneous coronary intervention using BVS at a single centre between June 2013 and June 2016 were included in this study (n=79). Percutaneous coronary intervention with BVS was performed according to conventional practice: predilatation, postdilatation and intracoronary assessment with optical coherence tomography (OCT) according to operator's preferences. The primary endpoint was Major Adverse Cardiovascular Events (MACE), defined as all-cause mortality, myocardial infarction and revascularization, at 120 days., Results: Forty-three (54.4%) patients underwent OCT assessment and 36 (45.6%) patients underwent angiography alone post-BVS insertion. There were no significant differences at baseline between both groups; a total of 13 (30.2%) patients who had intracoronary OCT imaging performed underwent further postdilatation after malapposed struts were identified. Although no deaths were observed, there was a significant difference seen in MACE over the follow-up period between OCT and angiography cohorts (4.7 vs. 19.4% respectively; P=0.042). There was a greater number of MACE in low-experienced operators., Conclusion: As visual assessment with angiography has poor specificity for identifying strut malapposition, intracoronary OCT should be undertaken in all patients postinsertion of BVS stents in inexperienced operators to appropriately assess for stent malapposition, and reduce the subsequent risk of MACE.

Aims: In silico studies have provided robust evidence that stent design affects local haemodynamic forces, which appear as a major determinant of clinical outcomes following stent implantation. However, the implications of different stent/scaffold configurations on local haemodynamic forces have not yet been investigated in vivo in a comparative fashion. The aim of this study was to compare the ESS distribution in two differently shaped scaffolds using OCT-based modelling., Methods and Results: Eight healthy mini pigs were implanted with six Absorb everolimus-eluting bioresorbable vascular scaffolds (Absorb BVS) and five Mirage sirolimus-eluting bioresorbable microfibre scaffolds (Mirage BRMS). Optical coherence tomography (OCT) was performed and strut protrusion was assessed post scaffold implantation. Following the reconstruction of coronary anatomy, blood flow simulation was performed and endothelial shear stress (ESS) was estimated on top of the struts and at luminal surface between the struts in each scaffold. The thicker struts in Absorb (152±140 μm) resulted in an increased protruded distance compared to Mirage (117±123 μm) (p=0.003). This had an effect on the local haemodynamic microenvironment. ESS at the top of the struts was higher in Absorb (1.69±1.20 Pa) than in Mirage (1.53±0.91 Pa) (p<0.001), but lower at inter-strut zones (0.60±0.51 Pa vs. 0.63±0.50 Pa; p<0.01) compared to Mirage. Both scaffold types revealed comparable percentages of vessel luminal surface exposed to recirculation., Conclusions: Absorb demonstrated higher shear stress on top of the struts compared to Mirage. However, in the inter-strut zones shear stress was higher in Mirage than in Absorb. Further research is required to examine the potential value of in vivo computational modelling in optimising scaffold configuration and clinical outcomes.

Introduction: It is well recognized that a lesion that does not cause a hemodynamically significant stenosis can trigger a sudden cardiac event through plaque rupture. As a diagnostic tool, intravascular imaging was developed to circumvent limitations of coronary angiography; however, none of the intravascular imaging devices are individually able to provide complete assessment of the plaque morphology, geometry, physiology and biology. Therefore, over the past few years an effort was made to develop hybrid intravascular imaging catheters to provide more complete evaluation of coronary plaque pathobiology. Areas covered: This paper aims to give an overview of the recent developments on 1) single-modality intravascular imaging devices; 2) hybrid intravascular imaging devices and 3) the hemodynamic analysis in models reconstructed from the fusion of intravascular imaging and angiographic data. Expert commentary: Within five years, most of the hybrid imaging techniques which are now in pre-clinical phase will be utilized in the clinical arena, as NIRS-IVUS. Software for online blood simulation is likely to be developed that will enable ESS calculation while the patient is in the catheterization laboratory.

Protrusion of scaffold struts is related with local coronary flow dynamics that can promote scaffold restenosis and thrombosis. That fact has prompted us to investigate in vivo the protrusion status of different types of scaffolds and their relationship with endothelial shear stress (ESS) distributions. Six Absorb everolimus-eluting Bioresorbable Vascular Scaffolds (Absorb, Abbott Vascular) and 11 Mirage sirolimus-eluting Bioresorbable Microfiber Scaffolds (Mirage, Manli Cardiology) were implanted in coronaries of eight mini pigs. Optical coherence tomography (OCT) was performed post-scaffold implantation and obtained images were fused with angiographic data to reconstruct the three dimensional coronary anatomy. Blood flow simulation was performed and ESS distribution was estimated for each scaffold. Protrusion distance was estimated using a dedicated software. Correlation between OCT-derived protrusion and ESS distribution was assessed for both scaffold groups. A significant difference was observed in the protrusion distances (156 ± 137 µm for Absorb, 139 ± 153 µm for Mirage; p = 0.035), whereas difference remained after adjusting the protrusion distances according to the luminal areas. Strut protrusion of Absorb is inversely correlated with ESS (r = -0.369, p < 0.0001), whereas in Mirage protrusion was positively correlated with EES (r = 0.192, p < 0.0001). Protrusion distance was higher in Absorb than in Mirage. The protrusion of the thick quadratic struts of Absorb has a tendency to lower shear stress in the close vicinity of struts. However, circular shape of the less thick struts of Mirage didn't show this trend in creating zone of recirculation around the struts. Strut geometry has different effect on the relationship between protrusion and shear stress in Absorb and Mirage scaffolds.

By providing valuable information about the coronary artery wall and lumen, intravascular imaging may aid in optimizing interventional procedure results and thereby could improve clinical outcomes following percutaneous coronary intervention (PCI). Intravascular optical coherence tomography (OCT) is a light-based technology with a tissue penetration of approximately 1 to 3 mm and provides near histological resolution. It has emerged as a technological breakthrough in intravascular imaging with multiple clinical and research applications. OCT provides detailed visualization of the vessel following PCI and provides accurate assessment of post-procedural stent performance including detection of edge dissection, stent struts apposition, tissue prolapse, and healing parameters. Additionally, it can provide accurate characterization of plaque morphology and provides key information to optimize post-procedural outcomes. This manuscript aims to review the current clinical and research applications of intracoronary OCT and summarize the analytic OCT imaging software packages currently available. © 2017 Wiley Periodicals, Inc., (© 2017 Wiley Periodicals, Inc.)

Background and Aim: Local hemodynamic changes are one of the main factors that determine the vessel wall biological response after stent/scaffold implantation. Computational fluid dynamic studies provide an opportunity to investigate the rheological effects of implanted stent/scaffold. The aim of this study was to assess the local hemodynamic microenvironment in scaffolded segments in porcine coronary models., Methods: In six epicardial coronary arteries of healthy mini-pigs, six Absorb bioresorbable vascular scaffolds (Absorb BVS) were implanted. Optical coherence tomography(OCT) was performed after scaffold implantation and the images were fused with the angiographic data to reconstruct the three-dimensional coronary artery anatomy. Blood flow simulations were performed, and endothelial shear stress(ESS) distribution was estimated for each scaffolded segment. In a linear mixed-effect model, the contributing factors for low (<1.0Pa) ESS levels were assessed. At 30-day post-implantation, histopathological assessment was performed at 2 scaffolds., Results: In scaffolded segments, the median ESS was 0.57 (IQR: 0.29-0.99) Pa. In linear mixed-effect analysis, cross-section area was associated with low shear stress levels. In scaffolded segments, the percentage of the recirculation zone per scaffolded luminal surface was 3.26±2.07%. At 30-day histopathological assessment of implanted vessel segments revealed minimal injury score, minimal neointimal inflammation and minimal adventitial inflammation scores with moderate endothelial coverage. Fibrin accumulation was seen at 95.69±2.47% of the struts., Conclusion: The thick rectangular strut design of the Absorb BVS incited flow disruptions with low shear stress inducing fibrin accumulation. CFD assessment can be used to guide improvements in the scaffold design for a more "hemo-compatible" geometry., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Markers of coronary plaque vulnerability, such as a high lipid burden, increased inflammatory activity, and a thin fibrous cap, have been identified in histological studies. In vivo, grayscale intravascular ultrasound (IVUS) provides more in-depth information on coronary artery plaque burden than conventional angiography but is unable to accurately distinguish between noncalcific tissue types within the plaque. An analysis of IVUS radiofrequency backscatter based on spectral pattern recognition, such as virtual histology IVUS, allows detailed scrutiny of plaque composition and classification of coronary lesions. This review discusses the virtual histology IVUS technology and its accuracy in identifying vulnerable plaque features, focusing on its use in predicting patient outcomes after acute coronary syndrome, and its limitations in clinical practice.

Drug eluting stents and particularly the fully bioresorbable drug-eluting scaffolds herald a new era in percutaneous treatment of coronary artery disease. There has been tremendous progress in drug eluting stents with fully biodegradable coating polymers and polymer-free devices with reservoir technology planting the anti-proliferative drug. Despite significant decreases in in-stent restenosis rates with drug eluting stents, limitations still remain before we are able to develop fully bioresorbable scaffolds. Enhanced mechanical flexibility that provides superior conformability to the vessel wall, resumption of the vasoreactivity in the follow-up period and improving visualization on non-invasive imaging modalities are some of the supremacies of the fully bioresorbable scaffolds. In this review, we aim to give a general view on the latest developments in metallic drug eluting stents and fully bioresorbable scaffolds.

Background: An increased body mass index (BMI) is associated with a high risk of cardiovascular disease and reduction in life expectancy. However, several studies reported improved clinical outcomes in obese patients treated for cardiovascular diseases. The aim of the present study is to investigate the impact of BMI on long-term clinical outcomes after implantation of zotarolimus eluting stents., Methods: Individual patient data were pooled from the RESOLUTE Clinical Program comprising five trials worldwide. The study population was sorted according to BMI tertiles and clinical outcomes were evaluated at 2-year follow-up., Results: Data from a total of 5,127 patients receiving the R-ZES were included in the present study. BMI tertiles were as follow: I tertile (≤ 25.95 kg/m(2) -Low or normal weight) 1,727 patients; II tertile (>25.95 ≤ 29.74 kg/m(2) -overweight) 1,695 patients, and III tertile (>29.74 kg/m(2) -obese) 1,705 patients. At 2-years follow-up no difference was found for patients with high BMI (III tertile) compared with patients with normal or low BMI (I tertile) in terms of target lesion failure (I-III tertile, HR [95% CI] = 0.89 [0.69, 1.14], P = 0.341; major adverse cardiac events (I-III tertile, HR [95% CI] = 0.90 [0.72, 1.14], P = 0.389; cardiac death (I-III tertile, HR [95% CI] = 1.20 [0.73, 1.99], P = 0.476); myocardial infarction (I-III tertile, HR [95% CI] = 0.86 [0.55, 1.35], P = 0.509; clinically-driven target lesion revascularization (I-III tertile, HR [95% CI] = 0.75 [0.53, 1.08], P = 0.123; definite or probable stent thrombosis (I-III tertile, HR [95% CI] = 0.98 [0.49, 1.99], P = 0.964., Conclusions: In the present study, the patients' body mass index was found to have no impact on long-term clinical outcomes after coronary artery interventions., (© 2015 Wiley Periodicals, Inc.)

Background: The distribution of thrombus-containing lesions (TCLs) in an all-comer population admitted with a heterogeneous clinical presentation (stable, ustable angina, or an acute coronary syndrome) and treated with percutaneous coronary intervention is yet unclear, and the long-term prognostic implications are still disputed. This study sought to assess the distribution and prognostic implications of coronary thrombus, detected by coronary angiography, in a population recruited in all-comer percutaneous coronary intervention trials., Methods and Results: Patient-level data from 3 contemporary coronary stent trials were pooled by an independent academic research organization (Cardialysis, Rotterdam, the Netherlands). Clinical outcomes in terms of major adverse cardiac events (major adverse cardiac events, a composite of death, myocardial infarction, and repeat revascularization), death, myocardial infarction, and repeated revascularization were compared between patients with and without angiographic TCL. Preprocedural TCL was present in 257 patients (5.8%) and absent in 4193 (94.2%) patients. At 3-year follow-up, there was no difference for major adverse cardiac events (25.3 versus 25.4%; P=0.683); all-cause death (7.4 versus 6.8%; P=0.683); myocardial infarction (5.8 versus 6.0%; P=0.962), and any revascularizations (17.5 versus 17.7%; P=0.822) between patients with and without TCL. The comparison of outcomes in groups weighing the jeopardized myocardial by TCL also did not show a significant difference. TCL were seen more often in the first 2 segments of the right (43.6%) and left anterior descending (36.8%) coronary arteries. The association of TCL and bifurcation lesions was present in 40.1% of the prespecified segments., Conclusions: TCL involved mainly the proximal coronary segments and did not have any effect on clinical outcomes. A more detailed thrombus burden quantification is required to investigate its prognostic implications., Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifiers: NCT00114972, NCT01443104, NCT00617084., (© 2015 American Heart Association, Inc.)

After 2 decades of development and use in interventional cardiology research, optical coherence tomography (OCT) has now become a core intravascular imaging modality in clinical practice. Its unprecedented spatial resolution allows visualization of the key components of the atherosclerotic plaque that appear to confer "vulnerability" to rupture-namely the thickness of the fibrous cap, size of the necrotic core, and the presence of macrophages. The utility of OCT in the evaluation of plaque composition can provide insights into the pathophysiology of acute coronary syndrome and the healing that occurs thereafter. A brief summary of the principles of OCT technology and a comparison with other intravascular imaging modalities is presented. The review focuses on the current evidence for the use of OCT in identifying vulnerable plaques in acute coronary syndrome and its limitations., (Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Drug-eluting stents (DES) have revolutionized the practice of interventional cardiology over the past decade. Although their efficacy has never been called into question, concerns have been raised regarding their safety, particularly with respect to very late stent thrombosis. These valid concerns have prompted extensive research into improving stent safety, with particular interest in modifying the permanent polymer used on first-generation DES. Subsequently, various new types of coronary stent have been developed, including DES with biocompatible polymers, DES with biodegradable polymers, polymer-free DES, and completely bioresorbable scaffolds. Some of these new DES are already available in clinical practice, and others are currently undergoing clinical evaluation. Improvements in stent performance have made detecting statistically robust and clinically relevant differences between contemporary devices difficult. The wide array of available stents enables the choice of device to be tailored to the individual patient.

Drug-eluting stents (DES) have transformed interventional cardiology over the past decade. Whilst their efficacy has rarely been called into question, there have been concerns over the safety of the early devices, which has prompted the development of new coronary stents. Many of these new devices have entered clinical practice, however questions remain as to whether they offer the improvements in clinical outcomes that were originally anticipated. In addition, there is a debate whether the reported high efficacy of these devices enables percutaneous coronary intervention (PCI) to be performed in patient and lesion sub-groups previous entirely the domain of the cardiac surgeon. This review paper addresses these outstanding questions.

Background: The long-term results after second generation everolimus eluting bioresorbable vascular scaffold (Absorb BVS) placement in small vessels are unknown. Therefore, we investigated the impact of vessel size on long-term outcomes, after Absorb BVS implantation., Methods: In ABSORB Cohort B Trial, out of the total study population (101 patients), 45 patients were assigned to undergo 6-month and 2-year angiographic follow-up (Cohort B1) and 56 patients to have angiographic follow-up at 1-year (Cohort B2). The pre-reference vessel diameter (RVD) was <2.5 mm (small-vessel group) in 41 patients (41 lesions) and ≥2.5 mm (large-vessel group) in 60 patients (61 lesions). Outcomes were compared according to pre-RVD., Results: At 2-year angiographic follow-up no differences in late lumen loss (0.29±0.16 mm vs 0.25±0.22 mm, p=0.4391), and in-segment binary restenosis (5.3% vs 5.3% p=1.0000) were demonstrated between groups. In the small-vessel group, intravascular ultrasound analysis showed a significant increase in vessel area (12.25±3.47 mm(2) vs 13.09±3.38 mm(2) p=0.0015), scaffold area (5.76±0.96 mm(2) vs 6.41±1.30 mm(2) p=0.0008) and lumen area (5.71±0.98 mm(2) vs 6.20±1.27 mm(2) p=0.0155) between 6-months and 2-year follow-up. No differences in plaque composition were reported between groups at either time point. At 2-year clinical follow-up, no differences in ischaemia-driven major adverse cardiac events (7.3% vs 10.2%, p=0.7335), myocardial infarction (4.9% vs 1.7%, p=0.5662) or ischaemia-driven target lesion revascularisation (2.4% vs 8.5%, p=0.3962) were reported between small and large vessels. No deaths or scaffold thrombosis were observed., Conclusions: Similar clinical and angiographic outcomes at 2-year follow-up were reported in small and large vessel groups. A significant late lumen enlargement and positive vessel remodelling were observed in small vessels.

Aims: The aim of this investigation was to determine the incidence and multivariable correlates of long-term (4-year) mortality in patients treated with surgical or percutaneous revascularization in the synergy between percutaneous coronary intervention (PCI) with TAXUS Express and Cardiac Surgery (SYNTAX) trial., Methods and Results: A total of 1800 patients were randomized to undergo coronary artery bypass graft (CABG) surgery (n = 897) or PCI (n = 903). Prospectively collected baseline and peri- and post-procedural data were used to determine independent correlates of 4-year all-cause death in the CABG and the PCI arms (Cox proportional hazards model). Four-year mortality rates in the CABG and the PCI arms were 9.0% [74 deaths (12 in-hospital)] and 11.8% [104 deaths (16 in-hospital)], respectively (log-rank P-value = 0.063). Censored data comprised 78 patients (8.7%) in the CABG arm, and 24 patients (2.7%) in the PCI arm (log-rank P-value < 0.001). Within the CABG arm, the strongest independent correlates of 4-year mortality were lack of discharge aspirin [hazard ratio (HR) 3.56; 95% CI: 2.04, 6.21; P < 0.001], peripheral vascular disease (PVD) (HR: 2.65; 95% CI: 1.49, 4.72; P = 0.001), chronic obstructive pulmonary disease, age, and serum creatinine. Within the PCI arm, the strongest independent correlate of 4-year mortality was lack of post-procedural anti-platelet therapy (HR: 152.16; 95% CI: 53.57, 432.22; P < 0.001), with 10 reported early (within 45 days) in-hospital deaths secondary to multifactorial causes precluding administration of anti-platelet therapy. Other independent correlates of mortality in the PCI arm included amiodarone therapy on discharge, pre-procedural poor left ventricular ejection fraction, a 'history of gastrointestinal bleeding or peptic ulcer disease', PVD (HR: 2.13; 95% CI: 1.26, 3.60; P = 0.005), age, female gender (HR: 1.60; 95% CI: 1.01, 2.56; P = 0.048), and the SYNTAX score (Per increase in 10 points: HR: 1.25; 95% CI: 1.06, 1.47; P = 0.007)., Conclusion: Independent correlates of 4-year mortality in the SYNTAX trial were multifactorial. Lack of discharge aspirin and lack of post-procedural anti-platelet therapy were the strongest independent correlates of mortality in the CABG and the PCI arms, respectively. Peripheral vascular disease is a common independent correlate of 4-year mortality and may be a marker of the severity of baseline coronary disease and risk of future native coronary disease (and extra-cardiac disease) progression.

The aim of this study is to describe a new method for three-dimensional (3D) reconstruction of coronary arteries using Frequency Domain Optical Coherence Tomography (FD-OCT) images. The rationale is to fuse the information about the curvature of the artery, derived from biplane angiographies, with the information regarding the lumen wall, which is produced from the FD-OCT examination. The method is based on a three step approach. In the first step the lumen borders in FD-OCT images are detected. In the second step a 3D curve is produced using the center line of the vessel from the two biplane projections. Finally in the third step the detected lumen borders are placed perpendicularly onto the path based on the centroid of each lumen border. The result is a 3D reconstructed artery produced by all the lumen borders of the FD-OCT pullback representing the 3D arterial geometry of the vessel.

Rituximab is an active agent for the treatment of Waldenstrom's macroglobulinemia. However, many patients do not respond to this agent and several others develop secondary resistance. In order to identify clinical and laboratory parameters that could predict a higher likelihood for response, we evaluated 54 patients who were treated with single-agent rituximab. Twenty-four patients (44%)exhibited > or = 50% reduction of serum monoclonal protein. Previously untreated and pretreated patients had the same probability for response. Low response rates were noted in patients with serum monoclonal protein level > or = 40 g/L (17%) and serum albumin level < 35 g/L (14%). Furthermore, a multivariate analysis indicated that high serum monoclonal protein and low albumin were the dominant variables associated with shorter time to progression. The presence of 2, 1, or none of these variables was associated with median times to progression of 4 months, 11 months, and approximately 48 months, respectively. We conclude that patients with low levels of monoclonal protein and normal albumin are the best candidates for treatment with rituximab.

The aim of this work was to evaluate a new semi-automated intravascular ultrasound (IVUS) border detection method. The method was used to identify the lumen and the external elastic membrane or the borders of stents in 80 IVUS images, randomly selected from 10 consecutive human coronary arteries. These semi-automated results were compared with observations of two experts. Several indices in each case were obtained in order fully to evaluate the method. The time required for identification of the borders was also recorded. The interobserver variability of the method ranged from 1.21% to 5.61%, the correlation coefficient from 0.98 to 0.99, the slope was close to unity (0.94-1.03), the y intercept close to zero and the Williams index value was close to unity (range 0.67-0.91). The time (mean+/-SD) required for the method to identify the borders of the different vessel layers for the whole IVUS sequence was 5.2+/-0.2 min. The results demonstrate that the method is reliable and capable of identifying rapidly and accurately the different vessel layers depicted in IVUS images.

Disturbances of acid-base balance and electrolyte abnormalities are commonly seen in patients with acute leukemia. Our study aimed at illuminating the probable pathogenetic mechanisms responsible for these disturbances in patients with acute leukemia admitted to our hospital. We studied 66 patients (24 men and 44 women) aged between 17 and 87 years old on their admission and prior to any therapeutic intervention. Patients with diabetes mellitus, acute or chronic renal failure, hepatic failure, patients receiving drugs that influence acid-base status and electrolyte parameters during the last month, such as corticosteroids, cisplatin, diuretics, antacids, aminoglycosides, amphotericin, penicillin, and K(+), PO(4)(3-), or Mg(2+) supplements were excluded. Forty-one patients had at least one acid-base or electrolyte disturbance. There were no significant differences in the incidence of acid-base balance and electrolyte abnormalities between patients with acute myeloid leukemia (AML) and patients with acute lymphoblastic leukemia (ALL). The most frequent electrolyte abnormality was hypokalemia, observed in 41 patients (63%), namely in 34 patients with AML, and 7 with ALL; the main underlying pathophysiologic mechanism was inappropriate kaliuresis. Furthermore, hypokalemic patients more frequently experienced concurrent electrolyte disturbances (i.e., hyponatremia, hypocalcemia, hypophosphatemia, and hypomagnesemia), as well as various acid-base abnormalities compared to normokalemic patients. Hypokalemia in patients with acute leukemia may serve as an indicator of multiple concurrent, interrelated electrolyte disturbances, especially in patients with AML., (Copyright 1999 Wiley-Liss, Inc.)

A case of angiofollicular lymph node hyperplasia of plasma cell type in a 60-year-old woman is reported. The patient presented with lymphadenopathy, splenomegaly, and fever. She responded dramatically to chlorambucil and corticosteroids and has remained free of disease for the last 30 months. The authors review and discuss the systemic cytotoxic treatment of this clinicopathologic entity.