Serial 3-Vessel Optical Coherence Tomography and Intravascular Ultrasound Analysis of Changing Morphologies Associated With Lesion Progression in Patients With Stable Angina Pectoris

Management of vulnerable patient phenotypes and acute coronary syndrome mechanisms

Atherosclerosis is a chronic vascular disease. Its prevalence increases with aging. However, atherosclerosis may also affect young subjects without significant exposure to the classical risk factors. Recent evidence indicates clonal hematopoiesis of indeterminate potential (CHIP) as a novel cardiovascular risk factor that should be suspected in young patients. CHIP represents a link between impaired bone marrow and atherosclerosis. Atherosclerosis may present with an acute symptomatic manifestation or subclinical events that favor plaque growth. The outcome of a plaque relies on a balance of innate and environmental factors. These factors can influence the processes that initiate and propagate acute plaque destabilization leading to intraluminal thrombus formation or subclinical vessel healing. Thirty years ago, the first autopsy study revealed that coronary plaques can undergo rupture even in subjects without a known cardiovascular history. Nowadays, cardiac magnetic resonance studies demonstrate that this phenomenon is not rare. Myocardial infarction is mainly due to plaque rupture and plaque erosion that have different pathophysiological mechanisms. Plaque erosion carries a better prognosis as compared to plaque rupture. Thus, a tailored conservative treatment has been proposed and some studies demonstrated it to be safe. On the contrary, plaque rupture is typically associated with inflammation and anti-inflammatory treatments have been proposed in response to persistently elevate biomarkers of systemic inflammation. In conclusion, atherosclerosis may present in different forms or phenotypes. Vulnerable patient phenotypes, identified by using intravascular imaging techniques, biomarkers, or even genetic analyses, are characterized by distinctive pathophysiological mechanisms. These different phenotypes merit tailored management.

Relationship between plaque burden and plaque vulnerability: Acute coronary syndromes versus chronic coronary syndrome

BACKGROUND

The relationship between plaque burden and microscopic characterization of plaque features as it pertains to clinical presentation has not been fully investigated. The aim of this study was to compare the relationship between plaque burden and plaque vulnerability in patients with acute coronary syndromes (ACS) versus chronic coronary syndrome (CCS).

METHODS

Patients who underwent both coronary computed tomography angiography (CTA) and optical coherence tomography (OCT) before coronary intervention were enrolled. All plaques were detected in culprit vessels using CTA, and total plaque volume (TPV) and OCT features were assessed at the corresponding sites. All plaques were divided into three groups according to the tertile levels of TPV (low TPV: <96.5 ​mm3, moderate TPV: 96.5-164.7 ​mm3, high TPV: ≥164.8 ​mm3).

RESULTS

A total of 990 plaques were imaged by OCT in 419 patients: 445 plaques in 190 (45.3%) patients with ACS and 545 in 229 (54.7%) with CCS. Macrophage was more prevalent in plaques with greater TPV in patients who presented with ACS but not in those who presented with CCS (low vs. moderate vs. high TPV group: macrophage 57.4% vs. 71.8% vs. 82.4% in ACS; 63.4% vs. 67.8% vs. 66.7% in CCS; interaction P ​= ​0.004). Lipid arc increased as TPV increased, especially in patients who presented with ACS. Conversely, the layer index increased as TPV increased in patients with CCS.

CONCLUSION

Greater plaque burden was closely related to higher levels of plaque vulnerability in ACS and greater volume of layered plaque in CCS.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT04523194.

Recurrent events after acute ST-segment elevation myocardial infarction: predictors and features of plaque progression and stent failure

OBJECTIVES

Patients with acute ST-segment elevation myocardial infarction (STEMI) are at high risk for recurrent coronary events (RCE). Non-culprit plaque progression and stent failure are the main causes of RCEs. We sought to identify the incidence and predictors of RCEs.

METHODS

Eight hundred thirty patients with STEMI were enrolled and followed up for 5 years. All patients underwent blood test analysis at hospital admission, at 1-month and at 12-month follow-up times. Patients were divided into RCE group and control group. RCE group was further categorized into non-culprit plaque progression and stent failure subgroups.

RESULTS

Among 830 patients with STEMI, 63 patients had a RCE (7.6%). At hospital admission, HDL was numerically lower in RCE group, while LDL at both 1-month and 12-month follow-up times were significantly higher in RCE group. Both HDL at hospital admission and LDL at 12-month follow-up were independently associated with RCEs (OR 0.90, 95% CI 0.81-0.99 and OR 1.041, 95% CI 1.01-1.07, respectively). RCEs were due to non-culprit plaque progression in 47.6% of cases, while in 36.5% due to stent failure. The mean time frame between pPCI and RCE was significantly greater for non-culprit plaque progression subgroup as compared to stent failure subgroup (27 ± 18 months and 16 ± 14 months, P  = 0.032).

CONCLUSION

RCEs still affect patients after pPCI. Low levels of HDL at admission and high levels of LDL at 12 months after pPCI significantly predicted RCEs. A RCE results in non-culprit plaque progression presents much later than an event due to stent failure.

The impact of statins treatments for plaque characteristics in stable angina pectoris patients with very low and high low-density lipoprotein cholesterol levels: an intracoronary optical coherence tomography study

Low-density lipoprotein cholesterol (LDL-C) levels are recommended according to the patient's risk factors based on guidelines. In patients achieving low LDL-C levels, the need for statins is uncertain, and the plaque characteristics of patients not treated with statins are unclear. In addition, the difference in plaque characteristics with and without statins is unclear in similarly high LDL levels. We evaluate the impact of statins on plaque characteristics on optical coherence tomography (OCT) in patients with very low LDL-C levels and high LDL-C levels. A total of 173 stable angina pectoris patients with 173 lesions undergoing OCT before percutaneous coronary intervention were evaluated. We divided the LDL-C levels into three groups: < 70 mg/dL (n = 48), 70 mg/dL ≤ LDL-C < 100 mg/dL (n = 71), and ≥ 100 mg/dL (n = 54). Among patients with LDL-C < 70 mg/dL, patients not treated with statins showed a significantly higher C-reactive protein level (0.27 ± 0.22 mg/dL vs. 0.15 ± 0.19 mg/dL, p = 0.049), and higher incidence of thin-cap fibroatheromas (TCFAs; 44% [7/16] vs. 13% [4/32], p = 0.021) than those treated with statins. Among patients with LDL-C level ≥ 100 mg/dL, patients treated with statins showed a significantly higher prevalence of familial hypercholesterolemia (FH) (38% [6/16] vs. 5% [2/38], p = 0.004), lower incidence of TCFAs (6% [1/16] vs. 39% [15/38], p = 0.013), healed plaques (13% [2/16] vs. 47% [18/38], p = 0.015), and higher incidence of fibrous plaques (75% [12/16] vs. 42% [16/38], p = 0.027) than patients not treated with statins. While patients achieved a low LDL-C, patients not treated with statins had high plaque vulnerability and high systemic inflammation. While patients had a high LDL-C level with a high prevalence of FH, patients treated with statins had stable plaque characteristics.

Intravascular Imaging in the Diagnosis and Management of Patients With Suspected Intracoronary Pathologies: A CJC White Paper

Intravascular imaging has become an integral part of the diagnostic and management strategies for intracoronary pathologies. In this White Paper we summarize current evidence and its implications on the use of intravascular imaging in interventional cardiology practice. The areas addressed are planning and optimization of percutaneous coronary intervention, management of stent failure, and evaluation of ambiguous coronary lesions and myocardial infarction with nonobstructive coronary disease. The findings presented followed the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system in an expert consensus process that involved a diverse writing group vetted by a review group. Expert consensus was achieved around 9 statements. Use of intravascular imaging in guiding percutaneous revascularization is supported by high-quality evidence, particularly for lesions with increased risk of recurrent events or stent failure. Specific considerations for intravascular imaging guidance of intervention in left main lesions, chronic occlusion lesions, and in patients at high risk of contrast nephropathy are explored. Use of intravascular imaging to identify pathologies associated with stent failure and guide repeat intervention, resolve ambiguities in lesion assessment, and establish diagnoses in patients who present with myocardial infarction with nonobstructive coronary disease is supported by moderate- to low-quality evidence. Each topic is accompanied by clinical pointers to aid the practicing interventional cardiologist in implementation of the White Paper findings. The findings presented in this White Paper will help to guide the use of intravascular imaging toward situations in which the balance of efficacy, safety, and cost are most optimal.

Cardiac Optical Coherence Tomography: History, Current Status, and Perspective

For more than 2 decades since the first imaging procedure was performed in a living patient, intravascular optical coherence tomography (OCT), with its unprecedented image resolution, has made significant contributions to cardiovascular medicine in the realms of vascular biology research and percutaneous coronary intervention. OCT has contributed to a better understanding of vascular biology by providing insights into the pathobiology of atherosclerosis, including plaque phenotypes and the underlying mechanisms of acute coronary syndromes such as plaque erosion, neoatherosclerosis, stent thrombosis, and myocardial infarction with nonobstructive coronary arteries. Moreover, OCT has been used as an adjunctive imaging tool to angiography for the guidance of percutaneous coronary intervention procedures to optimize outcomes. However, broader application of OCT has faced challenges, including subjective interpretation of the images and insufficient clinical outcome data. Future developments including artificial intelligence-assisted interpretation, multimodality catheters, and micro-OCT, as well as large prospective outcome studies could broaden the impact of OCT on cardiovascular medicine.

Higher triglyceride levels are associated with the higher prevalence of layered plaques in non-culprit coronary plaques

High triglyceride (TG) levels have been recognized as a risk factor for cardiovascular events in patients with coronary artery disease (CAD). This study aimed to clarify the association between TG levels and characteristics of non-culprit coronary plaques in patients with CAD. A total of 531 consecutive patients with stable CAD who underwent percutaneous coronary intervention for culprit lesions and optical coherence tomography (OCT) assessment of non-culprit plaques in the culprit vessel were included in this study. The morphology of the non-culprit plaques assessed by OCT imaging were compared between the higher TG (TG ≥ 150 mg/dL, n = 197) and lower TG (TG < 150 mg/dL, n = 334) groups. The prevalence of layered plaques (40.1 vs. 27.5%, p = 0.004) was significantly higher in the higher TG group than in the lower TG group, although the prevalence of other plaque components was comparable between the two groups. High TG levels were an independent factor for the presence of layered plaques (odds ratio 1.761, 95% confidence interval 1.213-2.558, p = 0.003) whereas high low-density lipoprotein cholesterol levels (≥ 140 mg/dL) and low eicosapentaenoic acid/arachidonic acid ratios (< 0.4) were independently associated with a higher prevalence of thin-cap fibroatheroma and macrophages. Higher TG levels were associated with a higher prevalence of layered plaques in non-culprit plaques among patients with stable CAD. These results may partly explain the effect of TG on the progression of coronary plaques and the increased incidence of recurrent events in patients with CAD.

Residual risks and evolving atherosclerotic plaques

Atherosclerotic disease of the coronary and carotid arteries is the primary global cause of significant mortality and morbidity. The chronic occlusive diseases have changed the epidemiological landscape of health problems both in developed and the developing countries. Despite the enormous benefit of advanced revascularization techniques, use of statins, and successful attempts of targeting modifiable risk factors, like smoking and exercise in the last four decades, there is still a definite "residual risk" in the population, as evidenced by many prevalent and new cases every year. Here, we highlight the burden of the atherosclerotic diseases and provide substantial clinical evidence of the residual risks in these diseases despite advanced management settings, with emphasis on strokes and cardiovascular risks. We critically discussed the concepts and potential underlying mechanisms of the evolving atherosclerotic plaques in the coronary and carotid arteries. This has changed our understanding of the plaque biology, the progression of unstable vs stable plaques, and the evolution of plaque prior to the occurrence of a major adverse atherothrombotic event. This has been facilitated using intravascular ultrasound, optical coherence tomography, and near-infrared spectroscopy in the clinical settings to achieve surrogate end points. These techniques are now providing exquisite information on plaque size, composition, lipid volume, fibrous cap thickness and other features that were previously not possible with conventional angiography.

Coronary artery disease reporting and data system (CAD-RADS), vascular inflammation and plaque vulnerability

BACKGROUND

Coronary artery disease reporting and data system (CAD-RADS) predicts future cardiovascular events in patients with coronary artery disease (CAD). However, information on vascular inflammation and vulnerability remains scarce.

METHODS

Patients who underwent coronary computed tomography angiography (CTA) and optical coherence tomography (OCT) prior to coronary intervention were enrolled. All three coronary arteries were evaluated for CAD-RADS score and pericoronary adipose tissue (PCAT) attenuation, while the culprit vessel was analyzed for plaque vulnerability by OCT.

RESULTS

A total of 385 patients with 915 lesions were divided into two groups based on CAD-RADS score: 103 (26.8%) were categorized as CAD-RADS 4b/5 and 282 (73.2%) as CAD-RADS ≤4a. Patients with CAD-RADS 4b/5 had a higher level of PCAT attenuation (mean of 3 coronary arteries) than those with CAD-RADS ≤4a (-68.4 ​± ​6.7 HU vs. -70.1 ​± ​6.5, P ​= ​0.022). The prevalence of macrophage was higher, and lipid index was greater in patients with CAD-RADS 4b/5 than CAD-RADS ≤4a (94.2% vs. 83.0%, P ​= ​0.004, 1845 vs. 1477; P ​= ​0.003). These associations were significant in the culprit vessels of patients with chronic coronary syndrome but not in those with acute coronary syndromes.

CONCLUSIONS

Higher CAD-RADS score was associated with higher levels of vascular inflammation and plaque vulnerability.

Relationship of OCT-defined plaque characteristics with CCTA-derived coronary inflammation and CMR-derived global coronary flow reserve in patients with acute coronary syndrome

BACKGROUND

The relationship of layered plaque detected by optical coherence tomography (OCT) with coronary inflammation and coronary flow reserve (CFR) remains elusive. We aimed to investigate the association of OCT-defined layered plaque with pericoronary adipose tissue (PCAT) inflammation assessed by coronary computed tomography angiography (CCTA) and global (G)-CFR assessed by cardiac magnetic resonance imaging (CMR) in patients with acute coronary syndrome (ACS).

METHODS

We retrospectively investigated 88 patients with first ACS who underwent preprocedural CCTA, OCT imaging of the culprit lesion prior to primary/urgent percutaneous coronary intervention (PCI), and postprocedural CMR. All patients were divided into two groups according to the presence and absence of OCT-defined layered plaque at the culprit lesion. Coronary inflammation was assessed by the mean value of PCAT attenuation (-190 to -30 HU) of the three major coronary vessels. G-CFR was obtained by quantifying absolute coronary sinus flow at rest and during maximum hyperemia. CCTA and CMR findings were compared between the groups.

RESULTS

In a total of 88 patients, layered plaque was detected in 51 patients (58.0%). The patients with layered plaque had higher three-vessel-PCAT attenuation value (-68.58 ± 6.41 vs. -71.60 ± 5.21 HU, P = 0.021) and culprit vessel-PCAT attenuation value (-67.69 ± 7.76 vs. -72.07 ± 6.57 HU, P = 0.007) than those with non-layered plaque. The patients with layered plaque had lower G-CFR value (median, 2.26 [interquartile range, 1.78, 2.89] vs. 3.06 [2.41, 3.90], P = 0.003) than those with non-layered plaque.

CONCLUSIONS

The presence of OCT-defined layered plaque at the culprit lesion was associated with high PCAT attenuation and low G-CFR after primary/urgent PCI in patients with ACS. OCT assessment of culprit plaque morphology and detection of layered plaque may help identify increased pericoronary inflammation and impaired CFR, potentially providing the risk stratification in patients with ACS and residual microvascular dysfunction after PCI.

Role of Quantitative Plaque Analysis and Fractional Flow Reserve Derived From Coronary Computed Tomography Angiography to Assess Plaque Progression

PURPOSE

To explore the role of quantitative plaque analysis and fractional flow reserve (CT-FFR) derived from coronary computed angiography (CCTA) in evaluating plaque progression (PP).

METHODS

A total of 248 consecutive patients who underwent serial CCTA examinations were enrolled. All patients' images were analyzed quantitatively by plaque analysis software. The quantitative analysis indexes included diameter stenosis (%DS), plaque length, plaque volume (PV), calcified PV, noncalcified PV, minimum lumen area (MLA), and remodeling index (RI). PP is defined as PAV (percentage atheroma volume) change rate >1%. CT-FFR analysis was performed using the cFFR software.

RESULTS

A total of 76 patients (30.6%) and 172 patients (69.4%) were included in the PP group and non-PP group, respectively. Compared with the non-PP group, the PP group showed greater %DS, smaller MLA, larger PV and non-calcified PV, larger RI, and lower CT-FFR on baseline CCTA (all P <0.05). Logistic regression analysis showed that RI≥1.10 (odds ratio [OR]: 2.709, 95% CI: 1.447-5.072), and CT-FFR≤0.85 (OR: 5.079, 95% CI: 2.626-9.283) were independent predictors of PP. The model based on %DS, quantitative plaque features, and CT-FFR (area under the receiver-operating characteristics curve [AUC]=0.80, P <0.001) was significantly better than that based rarely on %DS (AUC=0.61, P =0.007) and that based on %DS and quantitative plaque characteristics (AUC=0.72, P <0.001).

CONCLUSIONS

Quantitative plaque analysis and CT-FFR are helpful to identify PP. RI and CT-FFR are important predictors of PP. Compared with the prediction model only depending on %DS, plaque quantitative markers and CT-FFR can further improve the predictive performance of PP.

Optical Coherence Tomography in Vulnerable Plaque and Acute Coronary Syndrome

Optical coherence tomography (OCT) is an intravascular imaging technique that uses near-infrared light. OCT provides high-resolution cross-sectional images of coronary arteries and enables tissue characterization of atherosclerotic plaques. OCT can identify plaque rupture, plaque erosion, and calcified nodule in culprit lesions of acute coronary syndrome. OCT can also detect important morphologic features of vulnerable plaques such as thin fibrous caps, large lipid cores, macrophages accumulation, intraplaque microvasculature, cholesterol crystals, healed plaques, and intraplaque hemorrhage.

Role of plaque imaging for identification of vulnerable patients beyond the stage of myocardial ischemia

Chronic coronary syndrome (CCS) is a progressive disease, which often first manifests as acute coronary syndrome (ACS). Imaging modalities are clinically useful in making decisions about the management of patients with CCS. Accumulating evidence has demonstrated that myocardial ischemia is a surrogate marker for CCS management; however, its ability to predict cardiovascular death or nonfatal myocardial infarction is limited. Herein, we present a review that highlights the latest knowledge available on coronary syndromes and discuss the role and limitations of imaging modalities in the diagnosis and management of patients with coronary artery disease. This review covers the essential aspects of the role of imaging in assessing myocardial ischemia and coronary plaque burden and composition. Furthermore, recent clinical trials on lipid-lowering and anti-inflammatory therapies have been discussed. Additionally, it provides a comprehensive overview of intracoronary and noninvasive cardiovascular imaging modalities and an understanding of ACS and CCS, with a focus on histopathology and pathophysiology.

Layered plaque and plaque volume in patients with acute coronary syndromes

BACKGROUND

Layered plaque is a signature of previous subclinical plaque destabilization and healing. Following plaque disruption, thrombus becomes organized, resulting in creation of a new layer, which might contribute to rapid step-wise progression of the plaque. However, the relationship between layered plaque and plaque volume has not been fully elucidated.

METHODS

Patients who presented with acute coronary syndromes (ACS) and underwent pre-intervention optical coherence tomography (OCT) and intravascular ultrasound (IVUS) imaging of the culprit lesion were included. Layered plaque was identified by OCT, and plaque volume around the culprit lesion was measured by IVUS.

RESULTS

Among 150 patients (52 with layered plaque; 98 non-layered plaque), total atheroma volume (183.3 mm³[114.2 mm³ to 275.0 mm³] vs. 119.3 mm³[68.9 mm³ to 185.5 mm³], p = 0.004), percent atheroma volume (PAV) (60.1%[54.7-60.1%] vs. 53.7%[46.8-60.6%], p = 0.001), and plaque burden (86.5%[81.7-85.7%] vs. 82.6%[77.9-85.4%], p = 0.001) were significantly greater in patients with layered plaques than in those with non-layered plaques. When layered plaques were divided into multi-layered or single-layered plaques, PAV was significantly greater in patients with multi-layered plaques than in those with single-layered plaques (62.1%[56.8-67.8%] vs. 57.5%[48.9-60.1%], p = 0.017). Layered plaques, compared to those with non-layered pattern, had larger lipid index (1958.0[420.9 to 2502.9] vs. 597.2[169.1 to 1624.7], p = 0.014).

CONCLUSION

Layered plaques, compared to non-layered plaques, had significantly greater plaque volume and lipid index. These results indicate that plaque disruption and the subsequent healing process significantly contribute to plaque progression at the culprit lesion in patients with ACS.

CLINICAL TRIAL REGISTRATION

http://www.

CLINICALTRIALS

gov , NCT01110538, NCT03479723, UMIN000041692.

Impact of the eicosapentaenoic acid to arachidonic acid ratio on plaque characteristics in statin-treated patients with coronary artery disease

BACKGROUND

A low eicosapentaenoic acid (EPA)/arachidonic acid (AA) ratio is associated with an increased risk of cardiovascular events in patients with coronary artery disease (CAD).

OBJECTIVE

To clarify the impact of the EPA/AA ratio on the characteristics of non-culprit coronary plaques in statin-treated patients with CAD.

METHODS

A total of 370 consecutive stable coronary disease patients treated with statins, who underwent percutaneous coronary intervention for the culprit lesion and optical coherence tomography (OCT) imaging of the non-culprit plaque in a culprit vessel were included. The characteristics of non-culprit plaques assessed using OCT were compared between the lower EPA/AA group (EPA/AA <0.4, n = 255) and the higher EPA/AA group (EPA/AA ≥0.4, n = 115).

RESULTS

The prevalence of lipid-rich plaque (58.8 vs. 41.7%, p = 0.003) and plaque with macrophages (56.5 vs. 31.3%, p <0.001) was significantly higher in the lower EPA/AA group than in the higher EPA/AA group. This association was observed even if the LDL-C level was <100 mg/dL. The prevalence of thin-cap fibroatheroma was significantly higher in patients with lower EPA/AA and higher LDL-C (≥100 mg/dL) than in those with higher EPA/AA and lower LDL-C (<100 mg/dL) (odds ratio: 2.750, 95% confidence interval: 1.182-6.988, p = 0.024). An EPA/AA <0.4 was independently associated with a higher prevalence of lipid-rich plaque, plaque with macrophages, and cholesterol crystals.

CONCLUSION

Lower EPA/AA ratio was associated with higher prevalence of vulnerable characteristics in non-culprit plaques. The present results suggest the importance of EPA/AA ratio on the secondary prevention of CAD.

Level of Vascular Inflammation Is Higher in Acute Coronary Syndromes Compared with Chronic Coronary Disease

BACKGROUND

Vascular inflammation has been recognized as one of the key factors in the pathogenesis of acute coronary syndromes (ACS). Pericoronary adipose tissue (PCAT) attenuation by computed tomography angiography has emerged as a marker specific for coronary artery inflammation. We examined the relationship between clinical presentation and coronary artery inflammation assessed by PCAT attenuation and coronary plaque characteristics.

METHODS

Patients with ACS or stable angina pectoris (SAP) who underwent preintervention coronary computed tomography angiography and optical coherence tomography were enrolled. PCAT attenuation was measured around the culprit lesion and in the proximal 40 mm of all coronary arteries. PCAT attenuation and optical coherence tomography findings were compared between patients with ACS versus SAP.

RESULTS

Among 471 patients (ACS: 198, SAP: 273), PCAT attenuation was higher in ACS patients than in SAP patients both at the culprit plaque level (-67.5±9.6 Hounsfield unit [HU] versus -71.5±11.0 HU, P<0.001) and at the culprit vessel level (-68.3±7.7 HU versus -71.1±7.9 HU, P<0.001). The mean PCAT attenuation of all 3 coronary arteries was also significantly higher in ACS patients than in SAP patients (-68.8±6.3 HU versus -70.5±7.1 HU, P=0.007). After adjusting patient characteristics, not only thin-cap fibroatheroma (OR: 3.41; 95% CI: 1.89-6.17) and macrophages (OR: 3.32; 95% CI: 1.76-6.26) but also PCAT attenuation around the culprit plaque (OR: 1.03; 95% CI: 1.00-1.05) was associated with the clinical presentation of ACS.

CONCLUSIONS

PCAT attenuation at culprit plaque, culprit vessel, and pan-coronary levels was higher in ACS patients than in SAP patients. Vascular inflammation appears to play a crucial role in the development of ACS.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04523194.

Optical coherence tomography in coronary atherosclerosis assessment and intervention

Since optical coherence tomography (OCT) was first performed in humans two decades ago, this imaging modality has been widely adopted in research on coronary atherosclerosis and adopted clinically for the optimization of percutaneous coronary intervention. In the past 10 years, substantial advances have been made in the understanding of in vivo vascular biology using OCT. Identification by OCT of culprit plaque pathology could potentially lead to a major shift in the management of patients with acute coronary syndromes. Detection by OCT of healed coronary plaque has been important in our understanding of the mechanisms involved in plaque destabilization and healing with the rapid progression of atherosclerosis. Accurate detection by OCT of sequelae from percutaneous coronary interventions that might be missed by angiography could improve clinical outcomes. In addition, OCT has become an essential diagnostic modality for myocardial infarction with non-obstructive coronary arteries. Insight into neoatherosclerosis from OCT could improve our understanding of the mechanisms of very late stent thrombosis. The appropriate use of OCT depends on accurate interpretation and understanding of the clinical significance of OCT findings. In this Review, we summarize the state of the art in cardiac OCT and facilitate the uniform use of this modality in coronary atherosclerosis. Contributions have been made by clinicians and investigators worldwide with extensive experience in OCT, with the aim that this document will serve as a standard reference for future research and clinical application.

Near-infrared spectroscopy to predict plaque progression in plaque-free artery regions

BACKGROUND

Positive near-infrared spectroscopy (NIRS) signals might be encountered in areas without evident artery wall thickening, being typically perceived as artefacts.

AIMS

We aimed to evaluate the utility of NIRS to identify artery wall regions associated with an increase in wall thickness (WT) as assessed by serial intravascular ultrasound (IVUS) and optical coherence tomography (OCT).

METHODS

In this prospective, single-centre study, patients presenting with acute coronary syndrome (ACS) underwent NIRS-IVUS and OCT assessment of a non-culprit artery at baseline and 12-month follow-up. For each vessel, 1.5 mm segments were identified, matched and divided into 45 sectors. The relationship between the change in IVUS-based WT (DWT) and the presence of NIRS-positive signals and OCT-detected lipid was evaluated using linear mixed models.

RESULTS

A total of 37 patients (38 vessels, 6,936 matched sectors) were analysed at baseline and 12 months. A total of 140/406 (34.5%) NIRS (+) sectors and 513/1,575 (32.6%) OCT-lipid (+) sectors were found to be located in thin (WT<0.5 mm) wall sectors. In the thin wall sectors, an increase in WT was significantly more pronounced in NIRS (+) vs NIRS (-) sectors (0.11 mm vs 0.06 mm, p<0.001). In the thick wall sectors, there was a decrease in WT observed that was less pronounced in the NIRS (+) versus NIRS (-) sectors (-0.08 mm vs -0.09 mm, p<0.001). Thin wall NIRS (+) OCT-lipid (+) sectors showed significant wall thickening (DWT=0.13 mm).

CONCLUSIONS

NIRS-positive signals in otherwise non-diseased arterial walls as assessed by IVUS could identify vessel wall regions prone to WT increase over 12-month follow-up. Our observations suggest that NIRS-positive signals in areas without evident wall thickening by IVUS should no longer be viewed as benign or imaging artefact.

Culprit and Non-Culprit Plaque Characteristics With vs. Without a Healed Phenotype in Patients With Acute Myocardial Infarction Caused by Plaque Erosion - A 3-Vessel OCT Study

BACKGROUND

Plaque erosion can occur quietly without causing clinical symptoms, followed by a healing process resulting in healed plaque. This study aimed to assess culprit and non-culprit plaque characteristics of patients with acute myocardial infarction (AMI) caused by plaque erosion with vs. without healed phenotype at the culprit plaque using optical coherence tomography (OCT).

METHODS AND RESULTS

A total of 117 AMI patients caused by plaque erosion who underwent OCT imaging of 3 coronary arteries were included. Patients were divided into 2 groups based on presence or absence of a healed phenotype at the culprit site. Culprit and non-culprit plaque characteristics were compared between the 2 groups. A healed phenotype at the culprit lesion was identified in 47.9% of AMI patients caused by plaque erosion. Patients with a healed phenotype at the culprit site were more frequently with hyperlipidemia, and had a higher prevalence of macrophage infiltration, microchannels, cholesterol crystals, and calcification at the culprit lesion. Moreover, patients with a healed phenotype at the culprit site had more non-culprit plaques and more characteristics of plaque vulnerability at the non-culprit lesion. In addition, patients with a healed phenotype at the culprit site presented with more severe luminal stenosis at both the culprit and non-culprit lesion.

CONCLUSIONS

A healed phenotype was identified in 47.9% of AMI patients caused by plaque erosion at the culprit site. A healed phenotype within eroded culprit plaque was associated with signs of pancoronary vulnerability and advanced atherosclerosis.

Healed neointima of in-stent restenosis lesions in patients with stable angina pectoris: an intracoronary optical coherence tomography study

The phenomenon to heal neointimal rupture or thrombus after coronary stenting occurs as well as in native coronary artery. We investigated clinical characteristics and neointimal vulnerability of healed neointima by optical coherence tomography (OCT). We treated 67 lesions by percutaneous coronary intervention for in-stent restenosis (ISR) and conducted OCT examinations. Healed neointima was defined as neointima having one or more layers with different optical densities and a clear demarcation from underlying components. ISR with healed neointima was found in 49% (33/67) of the lesions. Compared to ISR without healed neointima, ISR with healed neointima showed significantly longer stent age (102 ± 72 vs. 31 ± 39 months, P < 0.001), lower frequency of dual antiplatelet therapy [42% (14/33) vs. 74% (25/34), P = 0.017], lower use of angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker (ACE-I or ARB) [61% (20/33) vs. 91% (31/34), P = 0.028], lower usage of second-generation drug-eluting stents (DESs) [36% (12/33) vs. 63% (22/34), P = 0.029], higher usage of thick-strut stents [42% (14/33) vs. 15% (5/34), P = 0.012], larger neointimal area (6.8 ± 2.6 vs. 5.2 ± 1.8 mm², P = 0.005), higher incidence of thin-cap fibroatheroma [58% (19/33) vs. 21% (7/34), P = 0.002], neointimal rupture [45% (15/33) vs. 9% (3/34), P = 0.001], and lower incidence of stent underexpansion [15% (5/33) vs. 44% (15/34), P = 0.010]. In conclusions, ISR with healed neointima was associated with neointimal vulnerability, stent age, stent type, stent strut thickness, stent expansion, antiplatelet therapy, and use of ACE-I or ARB.

Coronary Atherosclerotic Plaque Regression: JACC State-of-the-Art Review

Over the last 3 decades there have been substantial improvements in treatments aimed at reducing cardiovascular (CV) events. As these treatments have been developed, there have been parallel improvements in coronary imaging modalities that can assess plaque volumes and composition, using both invasive and noninvasive techniques. Plaque progression can be seen to precede CV events, and therefore, many studies have longitudinally assessed changes in plaque characteristics in response to various treatments, aiming to demonstrate plaque regression and improvements in high-risk features, with the rationale being that this will reduce CV events. In the past, decisions surrounding treatments for atherosclerosis have been informed by population-based risk scores for initiation in primary prevention and low-density lipoprotein cholesterol levels for titration in secondary prevention. If outcome data linking plaque regression to reduced CV events emerge, it may become possible to directly image plaque treatment response to guide management decisions.

Impact of triglyceride levels on plaque characteristics in patients with coronary artery disease

BACKGROUND

High triglyceride (TG) levels have been demonstrated to be a risk factor for coronary artery disease. This study aimed to clarify the impact of TG levels on the characteristics of coronary plaques.

METHODS

A total of 850 consecutive patients who underwent optical coherence tomography (OCT) imaging of the culprit lesion were included. The morphologies of culprit plaques were compared between the higher TG group (nonfasting TG levels ≥150 mg/dL, n = 337) and the lower TG group (nonfasting TG <150 mg/dL, n = 513).

RESULTS

The prevalence of lipid-rich plaques (43% vs. 33%, p = 0.005), thin-cap fibroatheromas (TCFAs) (24% vs. 17%, p = 0.015) and macrophages (40% vs. 31%, p = 0.006) was significantly higher in the higher TG group than in the lower TG group. In addition to a high low-density lipoprotein cholesterol (LDL-C) level (≥140 mg/dL), high TGs (≥150 mg/dL) were identified as an independent factor for the presence of TCFAs (odds ratio 1.465, 95% confidence interval 1.004-2.137, p = 0.048). Among patients with lower LDL-C levels (<100 mg/dL), the prevalence of macrophages (38% vs. 26%, p = 0.007) and layered plaques (48% vs. 38%, p = 0.019) was significantly higher in the higher TG group than in the lower TG group.

CONCLUSIONS

Higher TG levels were associated with a higher prevalence of TCFAs in culprit coronary lesions. The prevalence of macrophages and layered plaques was more frequently observed in patients with higher TGs than those with lower TGs among patients with LDL-C < 100 mg/dL.

Human Atherosclerotic Plaque Progression Is Dependent on Apoptosis According to Bomb-Pulse 14C Dating

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Individuals with rapidly progressing atherosclerotic plaques are at higher risk to experience acute complications. Using a ¹⁴C bomb-pulse dating method, we explored the importance of different biological components for the timeframe of plaque progression in human atherosclerosis.

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According to the ¹⁴C bomb-pulse dating method, increased apoptosis was the main component associated with a young physical plaque age, reflecting a rapid progression.

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Physically young atherosclerotic plaques also had more apoptotic cells and larger cores than physically old plaques.

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Our findings in combination with recent advances in imaging techniques could guide future diagnostic imaging strategies to identify rapidly progressing plaques or therapeutic targets, halting plaque progression.

Individuals with rapidly progressing atherosclerotic plaques are at higher risk of experiencing acute complications. Currently, we lack knowledge regarding factors in human plaque that cause rapid progression. Using the ¹⁴C bomb-pulse dating method, we assessed the physical age of atherosclerotic plaques and which biological processes were associated with rapidly progressing plaques. Interestingly, increased apoptosis was the main component associated with a young physical plaque age, reflecting rapid plaque progression. Our findings in combination with recent advances in imaging techniques could guide future diagnostic imaging strategies to identify rapidly progressing plaques or therapeutic targets, halting plaque progression.

Predictors for layered coronary plaques: an optical coherence tomography study

Healed coronary plaques, morphologically characterized by a layered pattern, are signatures of previous plaque disruption and healing. Recent optical coherence tomography (OCT) studies showed that layered plaque is associated with vascular vulnerability. However, factors associated with layered plaques have not been studied. The aim of this study was to investigate predictors for layered plaque at the culprit plaques and at non-culprit plaques. Patients with coronary artery disease who underwent pre-intervention OCT imaging of the culprit lesion were included. Layered plaques were defined as plaques with one or more layers of different optical density and a clear demarcation from underlying components. Among 313 patients, layered plaque at the culprit lesion was observed in 18.8% of ST-segment elevation myocardial infarction patients, 36.3% of non-ST-segment elevation acute coronary syndrome patients, and 53.4% of stable angina pectoris (SAP) patients (p < 0.001). In the multivariable model, SAP, multivessel disease, type B2/C lesion, and diameter stenosis > 70% were independent predictors for layered plaque at the culprit lesion. In addition, 394 non-culprit plaques in 190 patients were assessed to explore predictors for layered plaques at non-culprit lesions. SAP, and thin-cap fibroatheroma and layered plaque at the culprit lesion were independent predictors for layered plaques at non-culprit lesions. In conclusion, clinical presentation of SAP was a strong predictor for layered plaque at both culprit plaques and non-culprit plaques. Development and biologic significance of layered plaques may be related to a balance between pan-vascular vulnerability and endogenous anti-thrombotic protective mechanism.

Clinical significance of healed plaque detected by optical coherence tomography: a 2-year follow-up study

Recent studies have shown that healed plaque at the culprit lesion detected by optical coherence tomography (OCT) is a sign of pan-vascular vulnerability and advanced atherosclerosis. However, the clinical significance of healed plaque is unknown. A total of 265 patients who had OCT imaging of a culprit vessel and 2-year clinical follow-up data were included. Patients were stratified based on the presence or absence of a layered plaque phenotype, defined as layers of different optical density by OCT at either culprit or non-culprit lesions. The association between layered plaque and major adverse cardiac events (MACE), defined as cardiac death, acute coronary syndromes (ACS), or revascularization, was studied. Among 265 patients, 96 (36.2%) had the layered plaque phenotype. Layered plaque was more frequently observed in stable angina pectoris patients than in ACS patients (57.8%vs. 25.1%, p < 0.001). The average clinical follow-up period was 672 ± 172 days. Cumulative MACE was significantly higher in patients with layered plaque (p = 0.041), which was primarily driven by the high revascularization rate at 2 years (p = 0.002). Multivariate regression analysis showed that presence of layered plaque and low-density lipoprotein cholesterol levels were independently associated with an increased risk of revascularization (p = 0.026, p = 0.008, respectively). Patients with healed plaque in the culprit vessel had a higher incidence of revascularization, as compared to those without healed plaque, at 2 years.

Clinical outcomes of low-intensity area without attenuation and cholesterol crystals in non-culprit lesions assessed by optical coherence tomography

BACKGROUND AND AIMS

Pathologists have shown that intraplaque hemorrhage contributes to plaque destabilization and is frequently co-located with cholesterol crystals (CC). Optical coherence tomography (OCT)-detected low-intensity area without attenuation (LIA) may represent intraplaque hemorrhage. We aimed to examine the prevalence and impact of OCT-detected LIA + CC in untreated non-culprit lesions (NCLs) on subsequent major adverse cardiac events (MACE).

METHODS

OCT imaged NCLs in the culprit vessel in the patients who underwent OCT-guided percutaneous coronary intervention were included. An NCL was a lesion with >90° of diseased arc (≥0.5 mm intimal thickness), length ≥2 mm, and >5 mm away from stent edge. CC was defined as a thin linear region of high intensity. NCL-related MACE includes cardiac death, myocardial infarction, or ischemia-driven revascularization attributed to NCLs.

RESULTS

We included 735 NCLs in 566 patients with 2.5 ± 0.7 years follow-up. The prevalence of concomitant LIA with CC (LIA + CC) was 15.5% (114/735). Three-year NCL-related MACE rate was 2.9% (20 events) at a lesion level and 15.6% (78 events) at a patient level. Untreated NCLs with LIA + CC had an increased risk for NCL-MACE (adjusted hazard ratio [HR] 3.09, 95% confidence interval [CI] 1.27-7.50, p = 0.01) along with thin-cap fibroatheroma (adjusted HR 4.38, 95% CI 1.44-13.30, p < 0.01) and minimum lumen area <3.5 mm² (adjusted HR 5.33, 95% CI 1.94-14.62, p < 0.01). Patients having ≥1 untreated NCL with LIA + CC had an increased risk for NCL-MACE (adjusted HR 1.95, 95% CI 1.19-3.19, p < 0.01).

CONCLUSIONS

An OCT-detected LIA + CC in an NCL was associated with subsequent NCL-MACE.

Characteristics of non-culprit plaques in acute coronary syndrome patients with layered culprit plaque

AIMS

Layered plaques represent signs of previous plaque destabilization. A recent study showed that acute coronary syndrome (ACS) patients with layered culprit plaque have more vulnerability at the culprit lesion and systemic inflammation. We aimed to compare the characteristics of non-culprit plaques between patients with or without layered plaque at the culprit lesion. We also evaluated the characteristics of layered non-culprit plaques, irrespective of culprit plaque phenotype.

METHODS AND RESULTS

We studied ACS patients who had undergone pre-intervention optical coherence tomography (OCT) imaging. The number of non-culprit lesions was evaluated on coronary angiogram and morphological characteristics of plaques were studied by OCT. In 349 patients, 99 (28.4%) had layered culprit plaque. The number of non-culprit plaques in patients with or without layered culprit plaque was similar (3.2 ± 0.8 and 2.8 ± 0.8, P = 0.23). Among 465 non-culprit plaques, 145 from patients with layered culprit plaque showed a higher prevalence of macrophage infiltration (71.0% vs. 60.9%, P = 0.050). When analysed irrespective of culprit plaque phenotype, layered non-culprit plaques showed higher prevalence of lipid (93.3% vs. 86.0%, P = 0.028), thin cap fibroatheroma (29.7% vs. 13.7%, P < 0.001), and macrophage infiltration (82.4% vs. 54.0%, P < 0.001) than non-layered plaques. Plaques with layered phenotype at both culprit and non-culprit lesions had the highest vulnerability.

CONCLUSION

In ACS patients, those with layered phenotype at the culprit lesion demonstrated greater macrophage infiltration at the non-culprit sites. Layered plaque at the non-culprit lesions was associated with more features of plaque vulnerability, particularly when the culprit lesion also had a layered pattern.

Wall shear stress estimated by 3D-QCA can predict cardiovascular events in lesions with borderline negative fractional flow reserve

BACKGROUND AND AIMS

There is some evidence of the implications of wall shear stress (WSS) derived from three-dimensional quantitative coronary angiography (3D-QCA) models in predicting adverse cardiovascular events. This study investigates the efficacy of 3D-QCA-derived WSS in detecting lesions with a borderline negative fractional flow reserve (FFR: 0.81-0.85) that progressed and caused events.

METHODS

In this retrospective cohort study, we identified 548 patients who had at least one lesion with an FFR 0.81-0.85 and complete follow-up data; 293 lesions (286 patients) with suitable angiographic characteristics were reconstructed using a dedicated 3D-QCA software and included in the analysis. In the reconstructed models blood flow simulation was performed and the value of 3D-QCA variables and WSS distribution in predicting events was examined. The primary endpoint of the study was the composite of cardiac death, target lesion related myocardial infarction or clinically indicated target lesion revascularization.

RESULTS

During a median follow-up of 49.4 months, 37 events were reported. Culprit lesions had a greater area stenosis [(AS), 66.1% (59.5-72.3) vs 54.8% (46.5-63.2), p<0.001], smaller minimum lumen area [(MLA), 1.66 mm² (1.45-2.30) vs 2.10 mm² (1.69-2.70), p=0.011] and higher maximum WSS [9.0 Pa (5.10-12.46) vs 5.0 Pa (3.37-7.54), p < 0.001] than those that remained quiescent. In multivariable analysis, AS [hazard ratio (HR): 1.06, 95% confidence interval (CI): 1.03-1.10, p=0.001] and maximum WSS (HR: 1.08, 95% CI: 1.02-1.14, p=0.012) were the only independent predictors of the primary endpoint. Lesions with an increased AS (≥58.6%) that were exposed to high WSS (≥7.69Pa) were more likely to progress and cause events (27.8%) than those with a low AS exposed to high WSS (7.4%) or those exposed to low WSS that had increased (12.8%) or low AS (2.7%, p<0.001).

CONCLUSIONS

This study for the first time highlights the potential value of 3D-QCA-derived WSS in detecting, among lesions with a borderline negative FFR, those that cause cardiovascular events.

Association of plasma trimethylamine N-Oxide level with healed culprit plaques examined by optical coherence tomography in patients with ST-Segment elevation myocardial infarction

BACKGROUND AND AIMS

Healed plaque is a hallmark of previous regional plaque rupture or erosion. We hypothesized that the plasma level of trimethylamine N-oxide (TMAO) is related to healed culprit plaque in ST-segment elevation myocardial infarction (STEMI) patients.

METHODS AND RESULTS

A prospective cohort of 206 patients with STEMI, who were examined by optical coherence tomography (OCT) was enrolled in our study. After exclusion, 156 patients were categorized into healed plaque (n = 54) and nonhealed plaque (n = 102) groups. Plasma TMAO levels were detected by stable isotope dilution liquid chromatography tandem mass spectrometry in these two groups. Increased age and low BMI were more common in patients with healed plaques than in those without healed plaques. Through OCT observation, plaque rupture (81.5% vs. 45.1%, p < 0.001), thin cap fibroatheroma (TCFA) and macrophages (42.6% vs. 20.6%, p = 0.004, 70.4% vs. 26.5%, p < 0.001, respectively) were more frequently seen in patients with healed plaques than in those without healed plaques. The TMAO level in patients with healed plaques was significantly higher than that in patients with nonhealed plaques (3.9 μM [2.6-5.1] vs. 1.8 μM [1.0-2.7], p < 0.001). Furthermore, the receiver operating characteristic curve showed that TMAO can be used as a potential biomarker to predict healed plaque presence with a cutoff value of 2.9 μM (AUC = 0.810, sensitivity: 72.2%, specificity: 81.4%).

CONCLUSIONS

Healed plaque in STEMI patients is associated with a high level of plaque vulnerability and inflammation. A high level of plasma TMAO can be a useful biomarker to differentiate STEMI patients with healed culprit plaques.

Intravascular Polarimetry: Clinical Translation and Future Applications of Catheter-Based Polarization Sensitive Optical Frequency Domain Imaging

Optical coherence tomography (OCT) and optical frequency domain imaging (OFDI) visualize the coronary artery wall and plaque morphology in great detail. The advent of these high-resolution intracoronary imaging modalities has propelled our understanding of coronary atherosclerosis and provided enhanced guidance for percutaneous coronary intervention. Yet, the lack of contrast between distinct tissue types and plaque compositions impedes further elucidation of the complex mechanisms that contribute to acute coronary syndrome (ACS) and hinders the prospective identification of plaques susceptible to rupture. Intravascular polarimetry with polarization-sensitive OFDI measures polarization properties of the coronary arterial wall using conventional intravascular imaging catheters. The quantitative polarization metrics display notable image contrast between several relevant coronary plaque microstructures that are difficult to identify with conventional OCT and OFDI. Tissues rich in collagen and smooth muscle cells exhibit birefringence, while lipid and macrophages cause depolarization. In this review, we describe the basic principles of intravascular polarimetry, discuss the interpretation of the polarization signatures, and outline promising avenues for future research and clinical implications.

Frequency, Predictors, Distribution, and Morphological Characteristics of Layered Culprit and Nonculprit Plaques of Patients With Acute Myocardial Infarction

Background:

Subclinical atherothrombosis and plaque healing may lead to rapid plaque progression. The histopathologic healed plaque has a layered appearance when imaged using optical coherence tomography. We assessed the frequency, predictors, distribution, and morphological characteristics of optical coherence tomography layered culprit and nonculprit plaques in patients with acute myocardial infarction.

Methods:

A prospective series of 325 patients with acute myocardial infarction underwent optical coherence tomography imaging of all 3 native coronary arteries. Layered plaque phenotype had heterogeneous signal-rich layered tissue located close to the luminal surface that was clearly demarcated from the underlying plaque.

Results:

Layered plaques were detected in 74.5% of patients with acute myocardial infarction. Patients with layered culprit plaques had more layered nonculprit plaques; and they more often had preinfarction angina, ST-segment–elevation myocardial infarction, higher low-density lipoprotein cholesterol, and absence of antiplatelet therapy. Layered plaques tended to cluster in the proximal segment of the left anterior descending artery and left circumflex artery but were more uniformly distributed in the right coronary artery. As compared with nonlayered plaques, layered plaques had greater optical coherence tomography lumen area stenosis at both culprit and nonculprit sites. The frequency of layered plaque phenotype ( P =0.038) and maximum area of layered tissue ( P <0.001) increased from nonculprit thin-cap fibroatheromas to nonculprit ruptures to culprit ruptures.

Conclusions:

Layered plaques were identified in 3-quarters of patients with acute myocardial infarction, especially in the culprit plaques of patients with ST-segment–elevation myocardial infarction. Layered plaques had a limited, focal distribution in the left anterior descending artery, and left circumflex artery but were more evenly distributed in the right coronary artery and were characterized by greater lumen narrowing at both culprit and nonculprit sites.

Graphic Abstract:

A graphic abstract is available for this article.

Predictors of Rapid Plaque Progression: An Optical Coherence Tomography Study

OBJECTIVES

This study sought to identify morphological predictors of rapid plaque progression.

BACKGROUND

Two patterns of plaque progression have been described: slow linear progression and rapid step-wise progression. The former pattern will cause stable angina when the narrowing reaches a critical threshold, whereas the latter pattern may lead to acute coronary syndromes or sudden cardiac death.

METHODS

Patients who underwent optical coherence tomography (OCT) imaging during the index procedure and follow-up angiography with a minimum interval of 6 months were selected. Nonculprit lesions with a diameter stenosis of ≥30% on index angiography were assessed. Lesion progression was defined as a decrease of angiographic minimum lumen diameter ≥0.4 mm at follow-up (mean, 7.1 months). Baseline morphological characteristics of plaques with rapid progression were evaluated by OCT. In a subgroup with follow-up OCT imaging for plaques with rapid progression, morphological changes from baseline to follow-up were assessed.

RESULTS

Among 517 lesions in 248 patients, 50 lesions showed rapid progression. These lesions had a significantly higher prevalence of lipid-rich plaque (76.0% vs. 50.5%, respectively), thin-cap fibroatheroma (TCFA) (20.0% vs. 5.8%, respectively), layered plaque (60.0% vs. 34.0%, respectively), macrophage accumulation (62.0% vs. 42.4%, respectively), microvessel (46.0% vs. 29.1%, respectively), plaque rupture (12.0% vs. 4.7%, respectively), and thrombus (6.0% vs. 1.1%, respectively) at baseline compared with those without rapid progression. Multivariate analysis identified lipid-rich plaque (odds ratio [OR]: 2.17; 95% confidence interval [CI]: 1.02 to 4.62; p = 0.045]), TCFA (OR: 5.85; 95% CI: 2.01 to 17.03; p = 0.001), and layered plaque (OR: 2.19; 95% CI: 1.03 to 4.17; p = 0.040) as predictors of subsequent rapid lesion progression. In a subgroup analysis for plaques with rapid progression, a new layer was detected in 25 of 41 plaques (61.0%) at follow-up.

CONCLUSIONS

Lipid-rich plaques, TCFA, and layered plaques were predictors of subsequent rapid plaque progression. A new layer, a signature of previous plaque disruption and healing, was detected in more than half of the lesions with rapid progression at follow-up. (Massachusetts General Hospital Optical Coherence Tomography Registry; NCT01110538).

Healed Plaques in Patients With Stable Angina Pectoris

OBJECTIVE

Healed plaques, signs of previous plaque destabilization, are frequently found in the coronary arteries. Healed plaques can now be diagnosed in living patients. We investigated the prevalence, angiographic, and optical coherence tomography features of healed plaques in patients with stable angina pectoris. Approach and Results: Patients with stable angina pectoris who had undergone optical coherence tomography imaging were included. Healed plaques were defined as plaques with one or more signal-rich layers of different optical density. Patients were divided into 2 groups based on layered or nonlayered phenotype at the culprit lesion. Among 163 patients, 87 (53.4%) had layered culprit plaque. Patients with layered culprit plaque had more multivessel disease (62.1% versus 44.7%, P=0.027) and more angiographically complex culprit lesions (64.4% versus 35.5%, P<0.001). Layered culprit plaques had higher prevalence of lipid plaque (83.9% versus 64.5%, P=0.004), macrophage infiltration (58.6% versus 35.5%, P=0.003), calcifications (78.2% versus 63.2%, P=0.035), and thrombus (28.7% versus 14.5%, P=0.029). Lipid index (P=0.001) and percent area stenosis (P=0.015) were greater in the layered group. The number of nonculprit plaques, evaluated using coronary angiograms, tended to be greater in patients with layered culprit plaque (4.2±2.5 versus 3.5±2.1, P=0.053). Nonculprit plaques in patients with layered culprit lesion had higher prevalence of layered pattern (P=0.002) and lipid phenotype (P=0.005). Lipid index (P=0.013) and percent area stenosis (P=0.002) were also greater in this group.

CONCLUSIONS

In patients with stable angina pectoris, healed culprit plaques are common and have more features of vulnerability and advanced atherosclerosis both at culprit and nonculprit lesions.

Lipid-rich large plaques in a non-culprit left main coronary artery and long-term clinical outcomes

BACKGROUND

An integrated backscatter (IB) intravascular ultrasound (IVUS) provides an information about tissue components and vulnerability of coronary plaques. The presence of vulnerable plaque in non-culprit lesion is associated with future clinical events. The purpose of this study was to assess the association between the characteristics of non-culprit left main coronary artery (LMCA) plaques evaluated by IB-IVUS and long-term clinical outcomes in patients undergoing percutaneous coronary intervention (PCI).

METHODS

Among the patients who underwent non-LMCA PCI, we studied 366 patients with adequate LMCA IVUS images. Conventional and IB-IVUS analyses of the LMCA segment were performed. Lipid-rich large plaque was defined as the presence of both a lager plaque volume and a higher percentage of the lipid component than the obtained median values. Major adverse cardiovascular events (MACE) included cardiac death, myocardial infarction, and unplanned revascularization.

RESULTS

The mean age of the patients was 68.5 ± 10.2 years, 79.8% were men. Median follow-up period was 6.0 years (IQR: 4.2-8.1 years). The incidence of MACE was significantly higher in patients with lipid-rich large plaques (P = .006). The incidence rates of cardiac death, myocardial infarction, and unplanned revascularization were significantly higher in patients with lipid-rich large plaques (P = .02, 0.004, and 0.02, respectively). Multivariate Cox regression analysis showed that the presence of a lipid-rich large plaque was significantly associated with MACE (HR: 1.74; 95%CI: 1.17-2.58; P = .006).

CONCLUSION

The presence of lipid-rich large plaques in a non-culprit LMCA can be associated with the long-term MACE in patients who have undergone PCI.

The Relation Between Optical Coherence Tomography-Detected Layered Pattern and Acute Side Branch Occlusion after Provisional Stenting of Coronary Bifurcation Lesions

BACKGROUND/PURPOSE

Layered pattern (presumed to be healed plaque after a thrombotic event) can be observed by optical coherence tomography (OCT). We sought to assess the ability of OCT-detected plaque composition to predict acute side branch (SB) occlusion after provisional bifurcation stenting.

METHODS

This is a retrospective observational study using pre-intervention OCT in the main vessel to predict Thrombolysis in Myocardial Infarction (TIMI) flow grade ≤1 in a SB (diameter ≥ 1.5 mm) after provisional bifurcation stenting. OCT-detected layered pattern was defined as plaque with a superficial layer that had a different optical intensity and a clear demarcation from underlying tissue.

RESULTS

Overall, 207 patients with stable coronary disease were included. SB occlusion occurred in 26/207 (12.6%) bifurcation lesions. Operators decided not to perform additional treatment, and TIMI flow did not improve to ≥2 in cases with SB occlusion. The prevalence of OCT-detected layered pattern was more common in lesions with versus without SB occlusion (88.5% versus 33.7%, p < 0.0001); OCT-detected layered pattern was more often located on the same side of the SB (73.9% versus 21.3%, p < 0.0001) circumferentially compared to lesions without SB occlusion. Multivariable analysis showed that OCT-detected layered pattern was an independent predictor of SB occlusion (odds ratio 18.8, 95% confidence interval 5.1-68.8, p < 0.0001) along with true bifurcation lesion and wider angiographic bifurcation angle.

CONCLUSIONS

The presence of an OCT-detected layered pattern near its ostium was a strong predictor of SB occlusion after provisional bifurcation stenting.