Search

Studies have shown that the quantitative flow ratio (QFR), recently introduced to assess lesion severity from coronary angiography, provides useful prognostic information; however the additive value of this technique over intravascular imaging in detecting lesions that are likely to cause events is yet unclear. We analysed data acquired in the PROSPECT and IBIS-4 studies, in particular the baseline virtual histology-intravascular ultrasound (VH-IVUS) and angiographic data from 17 non-culprit lesions with a presumable vulnerable phenotype (i.e., thin or thick cap fibroatheroma) that caused major adverse cardiac events or required revascularization (MACE) at 5-year follow-up and from a group of 78 vulnerable plaques that remained quiescent. The segments studied by VH-IVUS were identified in coronary angiography and the QFR was estimated. The additive value of 3-dimensional quantitative coronary angiography (3D-QCA) and of the QFR in predicting MACE at 5 year follow-up beyond plaque characteristics was examined. It was found that MACE lesions had a greater plaque burden (PB) and smaller minimum lumen area (MLA) on VH-IVUS, a longer length and a smaller minimum lumen diameter (MLD) on 3D-QCA and a lower QFR compared with lesions that remained quiescent. By univariate analysis MLA, PB, MLD, lesion length on 3D-QCA and QFR were predictors of MACE. In multivariate analysis a low but normal QFR (> 0.80 to < 0.97) was the only independent prediction of MACE (HR 3.53, 95% CI 1.16-10.75; P = 0.027). In non-flow limiting lesions with a vulnerable phenotype, QFR may provide additional prognostic information beyond plaque morphology for predicting MACE throughout 5 years.

Objectives: This study sought to examine the utility of multimodality intravascular imaging and of the endothelial shear stress (ESS) distribution to predict atherosclerotic evolution., Background: There is robust evidence that intravascular ultrasound (IVUS)-derived plaque characteristics and ESS distribution can predict, with however limited accuracy, atherosclerotic evolution; nevertheless, it is yet unclear whether multimodality imaging and ESS mapping enable more accurate prediction of coronary plaque progression., Methods: A total of 44 patients admitted with a myocardial infarction that had successful revascularization and 3-vessel IVUS and optical coherence tomography (OCT) imaging at baseline and 13-month follow-up were included in the study. The IVUS data acquired at baseline in the nonculprit vessels were fused with x-ray angiography to reconstruct coronary anatomy and in the obtained models blood flow simulation was performed and the ESS was estimated. The baseline plaque characteristics and ESS distribution were used to identify predictors of disease progression: defined as a lumen reduction and an increase in plaque burden at follow-up., Results: Seventy-three vessels were included in the final analysis. Baseline ESS and the IVUS-derived but not the OCT-derived plaque characteristics were independently associated with a decrease in lumen area and an increase in plaque burden. Low ESS (odds ratio: 0.45; 95% confidence interval: 0.28 to 0.71; p < 0.001) and plaque burden (odds ratio: 0.73; 95% confidence interval: 0.54 to 0.97; p = 0.030) were the only independent predictors of disease progression at follow-up. The accuracy of the IVUS-derived plaque characteristics in predicting disease progression did not improve when ESS (AUC: 0.824 vs. 0.847; p = 0.127) or when OCT variables and ESS (AUC: 0.842; p = 0.611) were added into the model., Conclusions: ESS and OCT-derived variables did not improve the efficacy of IVUS in predicting disease progression. Further research is required to investigate whether multimodality imaging combined with ESS mapping will allow more reliable vulnerable plaque detection. (Comparison of Biomatrix Versus Gazelle in ST-Elevation Myocardial Infarction [STEMI] [COMFORTABLE]; NCT00962416)., (Copyright © 2020 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objective: Fractional flow reserve (FFR) is regarded as the gold standard for the physiological assessment of intermediate coronary artery stenoses. However, FFR does not allow assessment of plaque morphology and lesion geometry. Intracoronary imaging techniques such as intravascular ultrasound (IVUS) and optical coherence tomography (OCT) can help treatment planning by optimising stent implantation, which can improve patient outcomes. The aim of this meta-analysis is to compare the efficacy of IVUS and OCT-derived metrics in detecting flow limiting stenoses in non-left main stem lesions., Methods: A systematic review of PubMed, Medline, and Cochrane databases was performed and identified studies examining the diagnostic accuracy of IVUS and OCT in detecting significant stenoses when compared to FFR., Results: A total of 33 (7537 lesions) studies (24 IVUS, 7 OCT and 2 IVUS & OCT studies) were included in the meta-analysis. Pooled analysis showed that IVUS- and OCT-derived minimum lumen area (MLA) had a similar sensitivity in predicting haemodynamically significant lesions (IVUS-MLA: 0.747 vs OCT-MLA 0.732, p = 0.519). However, OCT-MLA had a higher specificity (0.763 vs 0.665, p < 0.001) and diagnostic accuracy in detecting flow-limiting stenoses than IVUS-MLA (AUC 0.810 vs 0.754, p = 0.045). Sub-analysis of the studies with the clinically significant FFR cut-off value of 0.80 yielded similar results demonstrating that OCT-MLA has a better accuracy than IVUS-MLA in detecting haemodynamically significant stenoses (AUC 0.809 vs 0.750, p = 0.034)., Conclusions: OCT with its superior image resolution appears to be the preferable intravascular imaging modality for the detection of haemodynamically significant stenoses in non-left main stem lesions., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objectives: This study assessed changes in optical coherence tomography (OCT)-defined plaque composition in patients with ST-elevation myocardial infarction (STEMI) receiving high-intensity statin treatment., Background: OCT is a high-resolution modality capable of measuring plaque characteristics including fibrous cap thickness (FCT) and macrophage infiltration. There is limited in vivo evidence regarding the effects of statins on OCT-defined coronary atheroma composition and no evidence in the context of STEMI., Methods: In the IBIS-4 (Integrated Biomarker Imaging Study-4), 103 patients underwent intravascular ultrasonography and OCT of 2 noninfarct-related coronary arteries in the acute phase of STEMI. Patients were treated with high-dose rosuvastatin for 13 months. Serial OCT imaging was available in 153 arteries from 83 patients. We measured FCT by using a semi-automated method. Co-primary endpoints consisted of the change in minimum FCT (measured in fibroatheromas) and change in macrophage line arc., Results: At 13 months, median low-density lipoprotein cholesterol had decreased from 128 mg/dl to 73.6 mg/dl. Minimum FCT, measured in 31 lesions from 27 patients, increased from 64.9 ± 19.9 μm to 87.9 ± 38.1 μm (p = 0.008). Macrophage line arc decreased from 9.6° ± 12.8° to 6.4° ± 9.6° (p < 0.0001). The secondary endpoint, mean lipid arc, decreased from 55.9° ± 37° to 43.5° ± 33.5°. In lesion-level analyses (n = 191), 9 of 13 thin-cap fibroatheromata (TCFAs) at baseline (69.2%) regressed to non-TCFA morphology, whereas 2 of 178 non-TCFA lesions (1.1%) progressed to TCFAs., Conclusions: In this observational study, we found significant increase in minimum FCT, reduction in macrophage accumulation, and frequent regression of TCFAs to other plaque phenotypes in nonculprit lesions of patients with STEMI treated with high-intensity statin therapy., (Copyright © 2019 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Aim: To examine the effect of endothelial shear stress (ESS) on the dynamic changes in plaque phenotype., Methods: Patients with myocardial infarction that had intravascular ultrasound-virtual histology (IVUS-VH) and optical coherence tomography (OCT) at baseline and 13-month follow-up were studied. The IVUS-VH data were used to reconstruct the nonculprit vessels, and in the obtained models the ESS was estimated in 3 mm segments. Plaque morphology was derived in each segment from IVUS-VH and OCT. Disease progression was defined as the presence of ≥2 out of the following criteria: reduction in lumen area, increase in plaque burden and change of plaque morphology to a more vulnerable phenotype. Linear mixed effects models were used to assess the effect of ESS in different phenotypes., Results: Sixty-eight vessels were included in the analysis. Low ESS was associated with plaque progression in all phenotypes. The effect of ESS on plaque burden (p for interaction=0.467) and phenotype (p for interaction=0.188) was similar in all plaque types, whereas the effect of ESS on the changes in lumen dimensions was more prominent in disease-free (β=0.70, p<0.001) than fibrotic/fibrocalcific (β=0.28, p<0.001) or lipid-rich plaques (β=0.15, p=0.015). Standalone IVUS-VH misclassified plaque morphology in one-third of the cases leading to erroneous estimations about the effect of ESS on plaque evolution in different phenotypes., Conclusions: The effect of ESS on plaque progression is similar in all phenotypes and cannot be accurately assessed by standalone IVUS-VH which often misclassifies plaque morphology. Therefore, multimodality imaging should be considered to examine the implications of ESS on plaque evolution., Clinical Trial Registration: NCT00962416; Post-results., Competing Interests: Competing interests: LR reports research grants by Abbott, Sanofi and Regeneron., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Introduction: Cardiovascular mortality of patients with combined peripheral arterial disease (PAD) and coronary artery disease (CAD) is twice as high as that in those with either disease alone. It is known that patients with PAD undergoing percutaneous coronary intervention have a higher incidence of adverse cardiac events such as myocardial infarction or target vessel revascularization., Objective: In this study, we compared the detailed characteristics of culprit and nonculprit plaques between patients with and those without PAD using optical coherence tomography., Patients and Methods: We performed propensity score matching using the following variables: (i) age; (ii) sex; (iii) clinical presentation; (iv) diabetes mellitus; (v) hyperlipidemia; (vi) smoking; (vii) hypertension; (viii) BMI; and (ix) coronary lesion location. Finally, we matched 34 culprit lesions and 30 nonculprit lesions in patients with PAD to 68 culprit lesions and 60 nonculprit lesions in patients without PAD (1 : 2 ratio)., Results: In culprit lesions, PAD patients when compared with those without PAD had a higher prevalence of lipid-rich plaque (73.5 vs. 51.5%; P=0.033), higher lipid index (1744±1110 vs. 1246±656; P=0.043), calcification (79.4 vs. 58.8%; P=0.039), macrophage accumulation (70.6 vs. 48.5%; P=0.034), and cholesterol crystals (32.4 vs. 10.3%; P=0.006). In nonculprit lesions, PAD patients had a higher prevalence of calcification (76.7 vs. 55.0%; P=0.046), macrophage accumulation (63.3 vs. 38.3%; P=0.025), and cholesterol crystals (36.7 vs. 16.7%; P=0.034)., Conclusion: Our study suggests greater coronary plaque vulnerability in both culprit and nonculprit lesions in patients with PAD. This observation underscores the need for more aggressive risk management in patients with combined PAD and coronary artery disease.

Objectives: Certain neointimal patterns including neoatherosclerosis (NA) are known to be associated with poor clinical outcome. The prevalence and time course of different neointimal patterns have not been studied systematically. The aim of this study was to investigate the serial changes in neointimal pattern after drug-eluting stent implantation., Patients and Methods: A total of 132 patients with 207 drug-eluting stents, who underwent two follow-up optical coherence tomography studies at 6 and 12 months, were included. Neointimal patterns were categorized as homogeneous, heterogeneous, layered, or NA using optical coherence tomography. Quantitative and qualitative analyses of neointima were carried out., Results: Both at 6 and at 12 months, the homogenous neointima was the predominant type (>75%), followed by the layered and the heterogeneous pattern. At 12 months, progression to NA was observed in 0.6% of the patients in the homogeneous group, in 5.6% of the patients in the heterogeneous group, and in 3.9% of the patients in the layered group. Regression to the homogeneous pattern was observed in 5.6% of the patients in the heterogeneous group and 11.5% of the patients in the layered group., Conclusion: The homogenous neointima is the predominant pattern both at 6 and at 12 months. The neointimal pattern changed between 6 and 12 months in 10.6% of stents. Further studies are needed to understand the mechanisms of these neointimal changes and their clinical significance.

SYNTAX score (SS) has been reported to be an independent predictor of future cardiac events including target lesion revascularization. The aim of this study was to assess the relation between SS and plaque characteristics and poststent vascular response using optical coherence tomography in coronary artery tree and left anterior descending artery (LAD) in patients with stable angina. A total of 179 lesions among 165 patients, including 100 lesions in LAD, were analyzed. Patients were stratified into tertiles. In pre-percutaneous coronary intervention analysis of whole coronary tree and LAD, lesions of the third tertile had the highest prevalence of lipid-rich plaque. Compared with the first tertile, the third tertile had greater lipid index, thinner fibrous cap, and higher prevalence of thin-cap fibroatheroma. In poststent optical coherence tomography, the incidence of stent edge dissection and irregular protrusion was higher in the third tertile compared with the first tertile in coronary tree analysis. In LAD analysis, the prevalence of irregular protrusion was the highest in the third tertile. In conclusion, high SS may reflect higher plaque vulnerability. Stent edge dissection and irregular protrusion were more frequent in patients with higher SS, indicating poor vascular response to stenting. Our results may explain higher cardiac event rate and target lesion revascularization in patients with higher SS., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Lipid-rich plaque (LRP) is thought to be a precursor to cardiac events. However, its clinical significance in coronary arteries has never been systematically investigated., Objectives: This study investigated the prevalence and clinical significance of LRP in the nonculprit region of the target vessel in patients undergoing percutaneous coronary intervention (PCI)., Methods: The study included 1,474 patients from 20 sites across 6 countries undergoing PCI, who had optical coherence tomography (OCT) imaging of the target vessel. Major adverse cardiac events (MACE) were defined as a composite of cardiac death, acute myocardial infarction, and ischemia-driven revascularization. Patients were followed for up to 4 years (median of 2 years)., Results: Lipid-rich plaque was detected in nonculprit regions of the target vessel in 33.6% of patients. The cumulative rate of nonculprit lesion-related MACE (NC-MACE) over 48 months in patients with LRP was higher than in those without LRP (7.2% vs. 2.6%, respectively; p = 0.033). Acute coronary syndrome at index presentation (risk ratio: 2.538; 95% confidence interval [CI]: 1.246 to 5.173; p = 0.010), interruption of statin use ≥1 year (risk ratio: 4.517; 95% CI: 1.923 to 10.610; p = 0.001), and LRP in nonculprit regions (risk ratio: 2.061; 95% CI: 1.050 to 4.044; p = 0.036) were independently associated with increased NC-MACE. Optical coherence tomography findings revealed that LRP in patients with NC-MACE had longer lipid lengths (p < 0.001), wider maximal lipid arcs (p = 0.023), and smaller minimal lumen areas (p = 0.003) than LRPs in patients without MACE., Conclusions: Presence of LRP in the nonculprit regions of the target vessel by OCT predicts increased risk for future NC-MACE, which is primarily driven by revascularization for recurrent ischemia. Lipid-rich plaque with longer lipid length, wider lipid arc, and higher degree of stenosis identified patients at higher risk of future cardiac events. (The Massachusetts General Hospital Optical Coherence Tomography Registry; NCT01110538)., (Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: The pathomechanisms underlying very late stent thrombosis (VLST) after implantation of drug-eluting stents (DES) are incompletely understood. Using optical coherence tomography, we investigated potential causes of this adverse event., Methods and Results: Between August 2010 and December 2014, 64 patients were investigated at the time point of VLST as part of an international optical coherence tomography registry. Optical coherence tomography pullbacks were performed after restoration of flow and analyzed at 0.4 mm. A total of 38 early- and 20 newer-generation drug-eluting stents were suitable for analysis. VLST occurred at a median of 4.7 years (interquartile range, 3.1-7.5 years). An underlying putative cause by optical coherence tomography was identified in 98% of cases. The most frequent findings were strut malapposition (34.5%), neoatherosclerosis (27.6%), uncovered struts (12.1%), and stent underexpansion (6.9%). Uncovered and malapposed struts were more frequent in thrombosed compared with nonthrombosed regions (ratio of percentages, 8.26; 95% confidence interval, 6.82-10.04; P<0.001 and 13.03; 95% confidence interval, 10.13-16.93; P<0.001, respectively). The maximal length of malapposed or uncovered struts (3.40 mm; 95% confidence interval, 2.55-4.25; versus 1.29 mm; 95% confidence interval, 0.81-1.77; P<0.001), but not the maximal or average axial malapposition distance, was greater in thrombosed compared with nonthrombosed segments. The associations of both uncovered and malapposed struts with thrombus were consistent among early- and newer-generation drug-eluting stents., Conclusions: The leading associated findings in VLST patients in descending order were malapposition, neoatherosclerosis, uncovered struts, and stent underexpansion without differences between patients treated with early- and new-generation drug-eluting stents. The longitudinal extension of malapposed and uncovered stent was the most important correlate of thrombus formation in VLST., (© 2016 American Heart Association, Inc.)

Background: Pathology studies have shown delayed arterial healing in culprit lesions of patients with acute coronary syndrome (ACS) compared with stable coronary artery disease (CAD) after placement of drug-eluting stents (DES). It is unknown whether similar differences exist in-vivo during long-term follow-up. Using optical coherence tomography (OCT), we assessed differences in arterial healing between patients with ACS and stable CAD five years after DES implantation., Methods and Results: A total of 88 patients comprised of 53 ACS lesions with 7864 struts and 35 stable lesions with 5298 struts were suitable for final OCT analysis five years after DES implantation. The analytical approach was based on a hierarchical Bayesian random-effects model. OCT endpoints were strut coverage, malapposition, protrusion, evaginations and cluster formation. Uncovered (1.7% vs. 0.7%, adjusted p=0.041) or protruding struts (0.50% vs. 0.13%, adjusted p=0.038) were more frequent among ACS compared with stable CAD lesions. A similar trend was observed for malapposed struts (1.33% vs. 0.45%, adj. p=0.072). Clusters of uncovered or malapposed/protruding struts were present in 34.0% of ACS and 14.1% of stable patients (adj. p=0.041). Coronary evaginations were more frequent in patients with ST-elevation myocardial infarction compared with stable CAD patients (0.16 vs. 0.13 per cross section, p=0.027)., Conclusion: Uncovered, malapposed, and protruding stent struts as well as clusters of delayed healing may be more frequent in culprit lesions of ACS compared with stable CAD patients late after DES implantation. Our observational findings suggest a differential healing response attributable to lesion characteristics of patients with ACS compared with stable CAD in-vivo., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Background--Low endothelial shear stress (ESS) is associated with plaque progression and vulnerability. To date, changes in plaque phenotype over time in relation to ESS have not been studied in humans. The aim of this study was to investigate whether local ESS can predict subsequent changes to plaque phenotype using optical coherence tomography. Methods and Results--A total of 25 coronary arteries from 20 patients who underwent baseline and 6-month follow-up optical coherence tomography were included. Arteries were divided into serial 3-mm segments, and plaque characteristics were evaluated in each segment. A total of 145 segments were divided into low-ESS group (ESS <1 Pa) and higher- ESS group (ESS =1 Pa) based on baseline computational flow dynamics analyses. At baseline, low-ESS segments had significantly thinner fibrous cap thickness compared with higher-ESS segments (128.2±12.3 versus 165.0±12.0 µm; P=0.03), although lipid arc was similar. At follow-up, fibrous cap thickness remained thin in low-ESS segments, whereas it significantly increased in higher-ESS segments (165.0±12.0 to 182.2±14.1 µm; P=0.04). Lipid arc widened only in plaques with low ESS (126.4±15.2° to 141.1±14.0°; P=0.01). After adjustment, baseline ESS was associated with fibrous cap thickness (ß, 9.089; 95% confidence interval, 2.539-15.640; P=0.007) and lipid arc (β, -4.381; 95% confidence interval, -6.946 to -1.815; P=0.001) at follow-up. Conclusions--Low ESS is significantly associated with baseline high-risk plaque phenotype and progression to higher-risk phenotype at 6 months. [ABSTRACT FROM AUTHOR]