The healing process of infarct-related plaques. Insights from 18 months of serial angioscopic follow-up

Angioscopic Comparison of Early- and Mid-Term Vascular Responses Following Treatment of ST-Elevation Acute Myocardial Infarction With Biodegradable vs. Durable Polymer Everolimus-Eluting Stents - A Prespecified Subanalysis of the MECHANISM AMI RCT

BACKGROUND

The vessel healing process after implantation of biodegradable polymer (BP) and durable polymer (DP) everolimus-eluting stent (EES) in ST-elevation myocardial infarction (STEMI) lesions remains unclear.

METHODS AND RESULTS

We conducted a multicenter prospective randomized controlled trial to compare early (2 weeks) and mid-term (12 months) vascular responses after implantation of BP-EES vs. DP-EES in STEMI patients. In this prespecified subanalysis, serial coronary angioscopy (CAS) analysis was performed in 15 stents in the BP-EES arm (n=10 patients) and 14 stents in the DP-EES arm (n=10 patients). At the 2-week follow-up, there was no significant difference in the estimated marginal means of the neointimal coverage grade (primary endpoint) between the 2 arms (mean [±SE] 0.00±0.00 in both arms; P>0.999). There were no significant differences between the BP-EES and DP-EES groups in the yellow color grade (1.046±0.106 vs. 0.844±0.114, respectively; P=0.201) or the presence of thrombus (77.8% vs. 88.8%, respectively; P=0.205). At 12 months, competent strut coverage, defined as yellow color grade ≤1, no thrombus, and a neointimal coverage grade ≥1 was achieved more frequently in the BP-EES than DP-EES arm (85.2% vs. 53.1%; adjusted odds ratio 2.11 [95% confidence interval 1.26-3.53]; P=0.023).

CONCLUSIONS

Neointimal coverage 2 weeks after implantation of BP-EES and DP-EES in STEMI lesions was comparable on CAS evaluation. However, at 1 year, BP-EES was independently associated with competent strut coverage.

Vascular healing in high-bleeding-risk patients at 3-month after everolimus-eluting stent versus biolimus A9-coated stent implantation: insights from analysis of optical coherence tomography and coronary angioscopy

The prevalence of high-bleeding-risk (HBR) patients who undergo coronary stenting has been reported as 20-40%. This study sought to assess vascular healing in HBR patients by coronary angioscopy (CAS) and optical coherence tomography (OCT). We prospectively analyzed 38 HBR patients with coronary artery disease who successfully underwent everolimus-eluting stent (EES) implantation (20 patients, 23 lesions) or drug-coated stent (DCS) implantation (18 patients, 18 lesions). Follow-up coronary angiography, CAS, and OCT were planned at 3 months after the procedure. The clinical characteristics and inclusion criteria of HBR were comparable between groups. CAS analysis showed that mean yellow color grade was significantly higher with EES than with DCS (1.33 [1.0, 1.67] vs. 1.0 [0.67, 1.5]; P = 0.04). In contrast, OCT analysis demonstrated that most struts in both groups were well-apposed struts with neointimal coverage (93.9% each; P = 1.00), and percentages of the mean neointimal area were comparable between EES and DCS (4.4 ± 3.5 mm² vs. 4.5 ± 4.1 mm²; P = 0.91). The frequency of uncovered struts was significantly lower with EES than with DCS (2.4% vs. 5.3%; P < 0.001), whereas the frequency of malapposed struts was significantly higher with EES than with DCS (3.5% vs. 0.8%; P < 0.001). During follow-up, no stent thrombosis or major bleeding complications were encountered in either group. Among HBR patients, both EES and DCS demonstrated good vascular healing at 3-month follow-up with some different features in CAS and OCT assessments.

A Parametric Study of Flushing Conditions for Improvement of Angioscopy Visibility

During an angioscopy operation, a transparent liquid called dextran is sprayed out from a catheter to flush the blood away from the space between the camera and target. Medical doctors usually inject dextran at a constant flow rate. However, they often cannot obtain clear angioscopy visibility because the flushing out of the blood is insufficient. Good flushing conditions producing clear angioscopy visibility will increase the rate of success of angioscopy operations. This study aimed to determine a way to improve the clarity for angioscopy under different values for the parameters of the injection waveform, endoscope position, and catheter angle. We also determined the effect of a stepwise waveform for injecting the dextran only during systole while synchronizing the waveform to the cardiac cycle. To evaluate the visibility of the blood-vessel walls, we performed a computational fluid dynamics (CFD) simulation and calculated the visible area ratio (VAR), representing the ratio of the visible wall area to the total area of the wall at each point in time. Additionally, the normalized integration of the VAR called the area ratio (ARVAR) represents the ratio of the visible wall area as a function of the dextran injection period. The results demonstrate that the ARVAR with a stepped waveform, bottom endoscope, and three-degree-angle catheter results in the highest visibility, around 25 times larger than that under the control conditions: a constant waveform, a center endoscope, and 0 degrees. This set of conditions can improve angioscopy visibility.

Angioscopic Findings of Stenosis Versus Occlusion in Femoropopliteal Artery Disease

BACKGROUND

Despite the increase in the number of patients with peripheral artery disease (PAD), the pathophysiology is not fully elucidated. Recently, angioscopy with a 0.48-megapixel equivalent resolution camera became available for patients with PAD. We aimed to compare the plaque component between native stenosis and occlusion in the femoropopliteal artery using this modality.

MATERIALS AND METHODS

Thirty-two consecutive patients who underwent endovascular treatment for native femoropopliteal artery disease with angioscopy were studied. The major angioscopic classifications of each lesion were defined as follows: atheromatous plaque (AP) was defined as luminal narrowing without any protrusion, calcified nodule (CN) was defined as a protruding bump with surface irregularity, a mainly reddish thrombus was defined as organizing thrombus (OG), and organized thrombus (OD) was defined by more than half of the thrombus showing a whitish intima-like appearance.

RESULTS

A total of 34 lesions (stenosis, n=18; occlusion, n=16) from 32 patients were included. All stenotic lesions showed AP or CN (n=8 [44%], n=10 [56%], respectively), whereas all occluded lesions showed OG or OD (n=5 [31%], n=11 [69%], respectively), which amounted to a statistically significant difference (p<0.001). In occluded lesions, stiff wires (>3 g) were required to cross all lesions classified as OD, whereas this was not always necessary for lesions classified as OG (11 [100%] of 11, 1 [25%] of 5, respectively; p=0.04). Yellow color plaques were observed to a similar degree in all angioscopic classifications. Major adverse limb events, defined as amputation and any reintervention at 12 months, were highly variable, depending on the angioscopic findings, and tended to be more frequently observed in CN and OD (13% in AP, 40% in CN, 0% in OT, and 36% in OD, p=0.25).

CONCLUSION

Angioscopy revealed varying components in stenosis and occlusion with different degrees of clinical impact. This may provide new information on the pathophysiology of PAD.

Prevalence of Healed Plaque and Factors Influencing Its Characteristics Under Optical Coherence Tomography in Patients With Coronary Artery Disease: A Systematic Review, Meta-Analysis, and Meta-Regression

Aim: The purpose of this study was to determine the prevalence of healed plaque and its characteristics under optical coherence tomography (OCT) through a formal systematic review, meta-analysis, and meta-regression. Methods and Results: Thirteen studies were selected from MEDLINE, EMBASE, Cochrane, and online databases. The overall incidence of healed plaques was 40% (95% CI: 39-42), with 37% (95% CI: 35-39) in patients with acute coronary syndrome (ACS) and with 46% (95% CI: 43-49) in patients with stable angina pectoris (SAP). The incidence of healed plaque among culprit plaques (48%, 95% CI: 46-50) was nearly two times higher than that among non-culprit plaques (24%, 95% CI: 21-27). The incidence of thin cap fibroatheroma (TCFA), plaque rupture, microvessel, macrophage accumulation, and calcification was significantly higher in the healed plaque group. Meta-regression revealed an association between smoking (P = 0.033) and healed plaque rupture. Gender (P = 0.047) was independently associated with macrophage accumulation, and mean low-density lipoprotein cholesterol (LDL-C) was independently associated with microvessel. Conclusions: In summary, with a total incidence of 40%, the incidence of healed plaques under OCT was higher in SAP than in ACS, and higher in culprit plaques than in non-culprit plaques. Higher incidence of TCFA, plaque rupture, microvessel, macrophage accumulation, and calcification was found in the healed-plaque group. Smoking, gender, and mean LDL-C level were associated with healed-plaque characteristics.

Intracoronary Thrombogenicity in Patients with Vasospastic Angina: An Observation Using Coronary Angioscopy

BACKGROUND

Despite significant interest in intracoronary thrombi in patients with vasospastic angina (VSA), the phenomenon remains unclarified. Therefore, we investigated a possible relationship using coronary angioscopy (CAS) in VSA patients.

METHODS

Sixty patients with VSA, for whom we could assess the spastic segment using CAS, were retrospectively studied. An intracoronary thrombus on CAS was a white thrombus and an erosion-like red thrombus. We verified the clinical characteristics and lesional characteristics as they determined the risk of intracoronary thrombus formation.

RESULTS

There were 18 (30%) patients with intracoronary thrombi. More of the patients with intracoronary thrombi were male, current smokers and had severe concomitant symptoms; however, no statistically significant difference was observed upon logistic regression analysis. There were 18 (26%) coronary arteries with intracoronary thrombi out of 70 coronary arteries recognised in the spastic segments. Furthermore, atherosclerotic changes and segmental spasms were significant factors responsible for such lesions.

CONCLUSION

Intracoronary thrombi occurred in 30% of VSA patients and much attention should be paid to the intracoronary thrombogenicity of VSA patients.

Clinical outcomes for intracoronary imaging strategies at different medical facilities in Japanese patients with coronary artery disease: the SAKURA imaging PCI Registry

The relationships between intracoronary imaging modalities and outcomes among Japanese patients with coronary artery disease (CAD) based on the type of medical facility providing outpatient care remain unclear. In this multicenter prospective study (SAKURA PCI Registry), we aimed to investigate the clinical outcomes of patients with CAD who underwent percutaneous coronary intervention (PCI) between April 2015 and December 2018. In this registry, we investigated differences in patient characteristics, intracoronary imaging modalities, and clinical outcomes between two types of medical facilities. Of the 414 patients enrolled in this registry, 196 were treated at two university hospitals, and 218 were treated at five community hospitals (median follow-up 11.0 months). The primary endpoint was clinically relevant events (CREs), including a composite of all-cause death, non-fatal myocardial infarction, clinically driven target lesion revascularization, stent thrombosis, stroke, and major bleeding. Patients treated at university hospitals had higher rates of diabetes (50% vs. 38%, p = 0.015) and malignant tumors (12% vs. 6%, p = 0.015) and more frequent use of multiple intracoronary imaging modalities than patients treated at community hospitals (21% vs. 0.5%, p < 0.001). The Kaplan-Meier incidence of CREs at 1 year was comparable between university hospitals and community hospitals (8.8% vs. 7.3%, p = 0.527, log-rank test). Despite the relatively higher risk among patients in university hospitals with frequent use of multi-intracoronary imaging modalities, adverse clinical events appeared to be comparable between patients with CAD treated at university and community hospitals in Japan.

Thrombus aspiration without stenting in a patient with anterior STEMI: Regression and healing of an unstable plaque assessed by OCT at 24 months of follow-up

In selected cases, when STEMI caused by mild or moderate degree lesion with a large concomitant thrombus, additional OCT-guided PCI strategy after thrombus removal allows us to defer stenting with the follow-up natural healing of the vessel wall.

Clinical significance of microvessels detected by in vivo optical coherence tomography within human atherosclerotic coronary arterial intima: a study with multimodality intravascular imagings

The significance of microvessels within atherosclerotic plaques is not yet fully clarified. Associated with plaque vulnerability. The aim of this study is to examine tissue characteristics of plaque with microvessels detected by optical coherence tomography (OCT) by use of a commercially available color-coded intravascular ultrasound (IVUS) and coronary angioscopy (CAS). The subjects examined comprised of 44 patients with stable angina pectoris who underwent percutaneous coronary intervention. Microvessels were defined as a tiny tubule with a diameter of 50-300 µm detected over three or more frames in OCT. We compared the total volume of microvessels with tissue component such as fibrotic, lipidic, necrotic, and calcified volume and the number of yellow plaque. In IVUS analysis, % necrotic volume and % lipidic volume were significantly correlated and % fibrotic volume was inversely significantly correlated with the total volume of microvessel (r = 0.485, p = 0.0009; r = 0.401, p = 0.007; r = - 0.432, p = 0.003, respectively). The number of plaque with an angioscopic yellow grade of two or more was significantly correlated with the total volume of microvessel (r = 0.461, p = 0.002). The greater the luminal volume of microvessels, the more the percent content of necrotic/lipidic tissue volume within plaque and the more the number of yellow plaques. These data suggested that microvessels within coronary plaque might be related to plaque vulnerability.

Clinical Importance of the LDL-C/Apolipoprotein B Ratio for Neointimal Formation after Everolimus-Eluting Stent Implantations

AIMS

Smaller low-density lipoprotein (LDL) particle size has been suggested to result in the development of endothelial dysfunction, atherosclerosis, and in-stent restenosis (ISR); however, little is known regarding the impact of the LDL particle size on the neointima formation leading to ISR after everolimus-eluting stent (EES) implantation.

METHODS

In this study, we have included 100 patients to examine the relationship between an LDL-C/apolipoprotein B (Apo B) ≤ 1.2, reportedly representing the LDL particle size, and the neointimal characteristics using optical coherence tomography (OCT) and coronary angioscopy (CAS) during the follow-up coronary angiography (CAG) period (8.8±2.5 months) after EES implantation. We divided them into two groups: LDL-C/Apo B ≤ 1.2 group (low LDL-C/Apo B group, n=53) and LDL-C/Apo B ＞1.2 group (high LDL-C/Apo B group, n=47).

RESULTS

The low LDL-C/Apo B group had a significantly larger neointimal volume (12.8±5.3 vs. 10.3±4.9 mm³, p=0.021) and lower incidence of a neointimal homogeneous pattern (71 vs. 89 %), higher incidence of a neointimal heterogeneous pattern (25 vs. 9 %) (p=0.006) and higher prevalence of macrophage accumulation (9 vs. 2 %) (p=0.030) as assessed via OCT, and, as per the CAS findings, a higher prevalence of yellow grade ≥ 2 (grade 2; adjusted residual: 2.94, grade 3; adjusted residual: 2.00, p=0.017) than the high LDL-C/Apo B group.

CONCLUSIONS

A low LDL-C/Apo B ratio was found to be strongly associated with neointimal proliferation and neointimal instability evidenced chronically by OCT and CAS. An LDL-C/Apo B ≤ 1.2 will be of aid in terms of identifying high-risk patients after EES implantation.

New Strategy to Prevent Acute Myocardial Infarction by Public Education - A Position Statement of the Committee on Public Education About Emergency Medical Care of the Japanese Circulation Society

Although many efforts have been made to prevent death from acute myocardial infarction (MI) by quick revascularization therapy and use of mechanical circulation support devices, and to prevent the occurrence of acute MI by optimal medical therapy, acute MI is still a leading cause of death worldwide. Because the majority of fatal MI cases occur outside hospital and death occurs so rapidly after MI onset, it is difficult to effectively prevent deaths from acute MI by improving the in-hospital treatment strategy of acute MI or by reducing the prehospital delay in the treatment. Therefore, we need a new strategy to prevent death from acute MI, mainly by preventing the occurrence of acute MI itself. In this review, we summarize the present status and propose a new strategy, the "STOP MI Campaign", to prevent acute MI by public education.

Quantitative Validation of the Coronary Angioscopic Yellow Plaque with Lipid Core Burden Index Assessed by Intracoronary Near-Infrared Spectroscopy

Aim: We aimed to validate the subjective and qualitative angioscopic findings by the objective and quantitative near-infrared spectroscopic (NIRS) assessment to compensate each other’s drawbacks.

Methods: This is a single-center prospective observational study. Patients undergoing a planned follow-up coronary angiography after percutaneous coronary intervention were prospectively enrolled from January 2018 to April 2019. The major three vessels were examined by NIRS-intravascular ultrasound, followed by coronary angioscopic evaluation. Yellow color grade on angioscopy was classified into four grades (0, white; 1, slight yellow; 2, yellow; and 3, intensive yellow) at a location of maximal lipid core burden index over 4 mm [LCBI (4)] on NIRS in each vessel.

Results: A total of 95 lesions in 44 patients (72.6±6.7 years, 75% male) were analyzed. LCBI (4) was significantly different among different yellow color grades by coronary angioscopy (ANOVA, p ＜0.001). Positive correlation was found between angioscopic yellow color grade and LCBI (4) (beta coefficient 164.8, 95% confidence interval 122.9–206.7; p ＜0.001). The best cutoff value of LCBI (4) to predict the presence of yellow plaque (yellow color grade ≥ 2) was 448 (sensitivity 79.3%, specificity 69.7%, C-statistic 0.800, 95% confidence interval 0.713–0.887, p ＜0.001).

Conclusion: The qualitative angioscopic assessment was objectively validated by the quantitative NIRS evaluation, which would be helpful for the reinterpretation of the existing evidences of both imaging modalities.

Impact of diabetes mellitus on the early-phase arterial healing after drug-eluting stent implantation

BACKGROUND

Early arterial healing after drug-eluting stent (DES) implantation may enable short dual-antiplatelet therapy (DAPT) strategy. The impact of diabetes mellitus (DM) on this healing has not been elucidated. We used coronary angioscopy (CAS) to compare intravascular status of DM and non-DM patients in the early phase after DES implantation.

METHODS

This study was a multicenter retrospective observational study. We analyzed CAS findings of 337 lesions from 270 patients evaluated 3-5 months after DES implantation. We divided the lesion into two groups: DM (n = 149) and non-DM (n = 188). We assessed neointimal coverage (NIC) grades (dominant, maximum and minimum), thrombus adhesion and maximum yellow color grade. NIC was graded as follows: grade 0, stent struts were not covered; grade 1, stent struts were covered by thin layer; grade 2, stent struts were buried under neointima. Yellow color was graded as grade 0, white; grade 1, light yellow; grade 2, yellow; grade 3, intensive yellow.

RESULTS

Minimum NIC grade was significantly lower in DM than in non-DM groups (p = 0.002), whereas dominant and maximum NIC grades were similar between them (p = 0.59 and p = 0.94, respectively), as were thrombus adhesion (44.3% vs. 38.8%, p = 0.32) and maximum yellow color grade (p = 0.78). A multivariate analysis demonstrated that DM was an independent predictor of minimum NIC of grade 0 (odds ratio: 2.14, 95% confidence interval: 1.19-3.86, p = 0.011).

CONCLUSIONS

DM patients showed more uncovered struts than non-DM patients 3-5 months after DES implantation, suggesting that the recent ultra-short DAPT strategy might not be easily applied to DM patients.

Impact of Neointimal Condition and Platelet Reactivity on Intrastent Thrombus at Long-Term Follow-up After 2nd- and 3rd-Generation Drug-Eluting Stent Implantation - Insights From a Coronary Angioscopy and Pharmacodynamic Study

BACKGROUND

Although the incidence of very late stent failure (VLSF) is reduced with newer generation drug-eluting stent (DES), the mechanism of VLSF has not been fully explored.

METHODS AND RESULTS

This study evaluated both local vascular healing using coronary angioscopy and systemic factors determined by platelet reactivity at long-term follow-up after 2nd- and 3rd-generation DES implantation in patients with acute coronary syndrome. Coronary angioscopy was performed to assess neointimal coverage (NIC), yellow color (YC) grade and presence of thrombus. The obtained findings were compared with 2nd- and 3rd-DES. Platelet aggregation was assessed by light transmittance aggregometry. 100 consecutive patients were prospectively enrolled: 2nd- (n=50) and 3rd-DES (n=50). 3rd-DES patients had significantly higher NIC grade and lower YC grade compared with 2nd-DES. The presence of thrombus was tended to be lower with 3rd-DES than with 2nd-DES (8% vs. 18%, P=0.11). Patients with thrombus had significantly higher maximum platelet aggregation and higher prevalence of high on-treatment platelet reactivity (HPR) than those without thrombus. Multivariable analysis showed stent strut exposure and HPR as independent predictors of thrombus.

CONCLUSIONS

Newer generation DES contribute to better vascular healing depending on the degree of neointimal coverage. In addition to local factors at the stented lesion, systemic factors such as degree of platelet reactivity might also contribute to VLSF.

Transient increase in blood thrombogenicity may be a critical mechanism for the occurrence of acute myocardial infarction

Although the mechanism for the occurrence of acute myocardial infarction (MI) has been investigated by many pathological and clinical studies, it has not been adequately clarified yet. Although the disruption of vulnerable plaque is a well-known cause of acute MI, there are many silent plaque disruptions detected in the coronary artery by intravascular imaging studies. Therefore, many vulnerable plaques may disrupt and heal without causing acute MI. Some additional mechanisms other than the disruption of vulnerable plaque would be essential for the onset of acute MI. On the other hand, blood thrombogenicity would change dynamically due to circadian rhythms and many other factors. The combination of plaque and blood thrombogenicity would play an important and determinant role for the onset of acute MI.

Impact of different coronary angioscopic findings on arterial healing one year after bioresorbable-polymer and second-generation durable-polymer drug-eluting stent implantation

BACKGROUND

The advantage of using bioresorbable-polymer drug-eluting stent (BP-DES) compared with second-generation durable-polymer drug-eluting stent (2G DP-DES) still remains controversial in clinical situations. The purpose of this study to evaluate the degree of re-endothelialization and the prevalence of high-grade yellow-colored plaque (YCP), which might concern arterial healing after BP-DES and 2G DP-DES implantation using a high-resolution coronary angioscopy (CAS).

METHODS

In total, 104 DESs (52: 2G DP-DES and 52: BP-DES) were prospectively observed using CAS 12±1 months after coronary intervention. The grade of neointimal coverage (NIC) over the stent was scored on a 4-point scale from 0 (no coverage) to 3 (complete coverage). YCP grade was also scored on a 4-point scale as 0 (white) to 3 (intensive yellow). High-grade YCP was defined as maximum grade ≥2. Moreover, the prevalence of high-grade YCP and the incidence of thrombus were investigated.

RESULTS

BP-DES revealed better dominant NIC grade and less NIC heterogeneity than 2G DP-DES (p=0.0001 and p=0.015, respectively). The prevalence of high-grade YCP was lower for BP-DES than for 2G DP-DES (p=0.05). However, the incidence of thrombus was not significantly different (p=0.41). Multivariate analysis identified that low-density lipoprotein cholesterol levels [odds ratio (OR), 1.03; 95% Confidence Interval (CI): 1.01-1.06, p=0.01] and the usage of BP-DES [OR, 0.36; 95% CI: 0.14-0.91, p=0.03] as independent predictors of high-grade YCP.

CONCLUSIONS

Compared with 2G DP-DES, BP-DES was less heterogeneous and well-covered NIC and less prevalence of the high-grade YCP implying optimal arterial healing.

Different vascular healing process between bioabsorbable polymer-coated everolimus-eluting stents versus bioresorbable vascular scaffolds via optical coherence tomography and coronary angioscopy (the ENHANCE study: ENdothelial Healing Assessment with Novel Coronary tEchnology)

Recent clinical trials have raised concerns about the safety and efficacy of ABSORB™ bioresorbable vascular scaffolds (BVS). The difference in the vascular healing process between SYNERGY™ bioabsorbable polymer-coated everolimus-eluting stents (BP-EES) and BVS remains unclear. The aim of the ENHANCE study was to compare vascular healing on BP-EES versus BVS by optical coherence tomography (OCT) and coronary angioscopy (CAS) at 4- and 12-month follow-ups. This is a prospective, non-randomized, single center clinical trial. Thirteen eligible patients with multivessel disease were enrolled. BP-EES and BVS were simultaneously implanted in the same patients, but in different coronary vessels. Imaging follow-up with both OCT and CAS was completed in 11 patients at 12 months. Neointimal coverage rates were similar between the two groups based on OCT measurements. The neointimal thickness of BP-EES was significantly thicker at the 12th month than at the 4th month, whereas the neointimal thickness of BVS did not change between the measurements taken at the 4th and 12th month. Existence of intra-stent thrombus was significantly higher in the BVS group, compared to the BP-EES group. On the other hand, CAS revealed that red-thrombi and yellow-plaque were more frequently observed in BVS at 4 months and up to 12-month follow-ups than in BP-EES. These findings suggested that the evidence of instability remained up to 12 months in the vascular healing with BVS, compared to that with BP-EES. Vascular healing of the stented wall was recognized at the very early phase after BP-EES implantation. However, vascular healing with BVS was still incomplete after 12 months.

Early vessel healing after implantation of biodegradable-polymer and durable-polymer drug-eluting stent: 3-month angioscopic evaluation of the RESTORE registry

The purpose of this study was to evaluate the vessel healing status 3 months after stent implantation of bioresorbable-polymer drug-eluting stents (BP-DESs) in comparison with durable-polymer DESs (DP-DESs) by angioscopy. Study design was a single-center all-comer prospective cohort study: the RESTORE registry (UMIN000033009). All patients who received successful angioscopic examination at planned 3-month follow-up after the DES implantation in the native coronary artery were enrolled. We evaluated main, maximum, minimum strut coverage grades and coverage heterogeneity score defined as a difference between maximum and minimum coverage grades. All lesions were divided into three segments: proximal, mid, and distal segments. A total of 108 patients (66.6 ± 10 years) with 124 lesions were analyzed (BP-DES 57 patients 61 lesions 226 segments vs. DP-DES 57 patients 63 lesions 203 segments; six patients had both BP-DES and DP-DES). Patient and lesion demographics, procedural characteristics were well balanced. Main coverage grade (mean ± standard error; 1.08 ± 0.02 vs. 1.05 ± 0.03, p = 0.354) and minimum coverage grade (1.00 ± 0.00 vs. 1.00 ± 0.00, p > 0.999) were not significantly different between BP-DES and DP-DES groups. Maximum coverage grade was significantly higher in the BP-DES than in the DP-DES (1.45 ± 0.04 vs. 1.35 ± 0.04, p = 0.049). Coverage heterogeneity score did not differ between BP-DES and DP-DES groups (1.05 ± 0.07 vs. 0.90 ± 0.07, p = 0.162). At 3-month follow-up, the current BP-DES had higher maximum stent coverage than the contemporary DP-DES, while main and minimum coverage grades and heterogeneity of the neointimal coverage were comparable. Further prospective randomized trials should be conducted to evaluate the clinical significance of the present imaging results.

The comparison of early healing 1-month after PCI among CoCr-everolimus-eluting stent (EES), biodegradable polymer (BP)-EES and BP-sirolimus-eluting stent: Insights from OFDI and coronary angioscopy

Background

Third-generation stents with abluminal biodegradable polymer (BP) might facilitate early healing. Therefore, we compared early healing between second-generation and third-generation stents using coronary angioscopy (CAS) and optical frequency domain imaging [OFDI].

Methods

We prospectively enrolled 30 consecutive patients with stent implantation for acute coronary syndrome (cobalt‑chromium [CoCr] everolimus-eluting stent [EES] [n = 10], BP-EES [n = 10], and BP-sirolimus eluting stent [SES] [n = 10]). All patients underwent CAS and OFDI 1 month after initial percutaneous coronary intervention. On OFDI, the stent coverage (SC), thrombus, and peri-strut low intensity area (PLIA) were assessed. CAS findings were recorded for the grade of SC, grade of yellow color (YC), and grade of the thrombus (TG).

Results

On OFDI, the incidences of any thrombus at the 1-month follow-up were 70%, 80%, and 80% in the CoCr-EES, BP-EES, and BP-SES groups, respectively. The percentage of coverage was comparable among the groups (CoCr-EES 79.8 vs. BP-EES 79.9 vs. BP-SES 80.1%, P = 0.96). However, the number of struts with PLIA was numerically higher in the BP-SES group than in the CoCr-EES and BP-EES groups (46.4 ± 25.1 vs. 21.6 ± 13.2 vs. 22.0 ± 7.2%, P = 0.08). In the CoCr-EES, BP-EES, and BP-SES groups, mean grades of SC were 1.25 ± 0.5, 1.25 ± 0.5, and 0.85 ± 0.70 (P = 0.60); mean grades of YC were 0.75 ± 0.5, 0.80 ± 0.45, and 0.88 ± 0.37 (P = 0.65), and mean grades of TG were 1.00 ± 1.00, 1.20 ± 0.83, and 0.88 ± 0.64 (P = 0.75), respectively.

Conclusion

Third-generation stents are not inferior to second-generation stents regarding stent coverage. However, PLIA on OFDI was often observed with BP-SESs, indicating involvement of the fibrin component.

Satisfactory arterial repair 1 year after ultrathin strut biodegradable polymer sirolimus-eluting stent implantation: an angioscopic observation

The ultrathin strut biodegradable polymer sirolimus-eluting stent (Orsiro, O-SES) exhibits satisfactory clinical outcomes. However, no report to date has documented the intravascular status of artery repair after O-SES implantation. We examined 5 O-SES placed in 4 patients (age 65 ± 12 years, male 75%) presenting with stable angina pectoris due to de novo lesions in native coronary arteries. Coronary angioscopy was performed immediately after percutaneous coronary intervention and 1 year later. Angioscopic images were analyzed to determine the following: (1) dominant grade of neointimal coverage (NIC) over the stent; (2) maximum yellow plaque grade; and (3) existence of thrombus. Yellow plaque grade was evaluated both immediately after stent implantation and at the time of follow-up observation. The other parameters were evaluated at the time of follow-up examination. NIC was graded as: grade 0, stent struts exposed; grade 1, struts bulging into the lumen, although covered; grade 2, struts embedded in the neointima, but translucent; grade 3, struts fully embedded and invisible. Yellow plaque severity was graded as: grade 0, white; grade 1, light yellow; grade 2, yellow; and grade 3, intensive yellow. Angioscopic findings at 1 year demonstrated the following: dominant NIC grade 1, grade 2, and grade 3 in 1, 2, and 2 stents, respectively; all stents were covered to some extent; focal thrombus adhesion was observed in only 1 stent. Yellow plaque grade did not change from immediately after stent implantation to follow-up. O-SES demonstrated satisfactory arterial repair 1 year after implantation.

Spinal endoscopy combined with selective CT myelography for dural closure of the spinal dural defect with superficial siderosis: technical note

The authors describe a new procedure to detect the tiny dural hole in patients with superficial siderosis (SS) and CSF leakage using a coronary angioscope system for spinal endoscopy and selective CT myelography using a spinal drainage tube. Under fluoroscopy, surgeons inserted the coronary angioscope into the spinal subarachnoid space, similar to the procedure of spinal drainage, and slowly advanced it to the cervical spine. The angioscope clearly showed the small dural hole and injured arachnoid membrane. One week later, the spinal drainage tube was inserted, and the tip of the drainage tube was located just below the level of the dural defect found by the spinal endoscopic examination. This selective CT myelography clarifies the location of the dural defect. During surgery, the small dural hole could be easily located, and it was securely sutured. It is sometimes difficult to detect the actual location of the small dural hole even with thin-slice MRI or dynamic CT myelography in patients with SS. The use of a coronary angioscope for the spinal endoscopy combined with selective CT myelography may provide an effective examination to assess dural closure of the spinal dural defect with SS in cases without obvious dural defects on conventional imaging.

Effect of Ezetimibe on Stabilization and Regression of Intracoronary Plaque - The ZIPANGU Study

BACKGROUND

Diminishing yellow color is associated with plaque stabilization. We assessed the hypothesis that a combination of ezetimibe and statin provides more effective plaque stabilization and regression than statin alone as assessed by plaque color.

METHODS AND RESULTS

Stable coronary artery disease patients (n=131) who underwent elective percutaneous coronary intervention and had yellow plaques were randomized to combination therapy (atorvastatin 10-20 mg and ezetimibe 10 mg/day; Group C) or statin monotherapy (atorvastatin 10-20 mg; Group M). Changes in plaque color and plaque volume during 9 months were assessed by angioscopy and intravascular ultrasound. Low-density lipoprotein cholesterol (LDL-C) decreased from 103±28 to 63±18 mg/dL in Group C (P<0.001) and from 100±28 to 75±17 mg/dL in Group M (P<0.001). Yellow color grade decreased significantly in both Group M (2.1±1.1 vs. 1.7±1.0, P=0.005) and Group C (2.2±1.2 vs. 1.8±1.2, P=0.002), but did not differ between the groups. %plaque volume did not change in Group M (48.5±10.2% vs. 48.2±10.4%, P=0.4), but decreased significantly in Group C (50.0±9.8% vs. 49.3±9.8%, P=0.03).

CONCLUSIONS

Compared with statin monotherapy, combination therapy with ezetimibe further reduced LDL-C levels. Significant plaque volume reduction was achieved by the combination therapy, but not statin monotherapy; however, plaque stabilization was similarly achieved by both therapies. Furthermore, reduction in plaque volume was dependent on reduction in LDL-C, regardless of whether it was achieved by statin alone or statin plus ezetimibe.

Impact of Paradoxical Decrease in High-density Lipoprotein Cholesterol Levels After Statin Therapy on Major Adverse Cardiovascular Events in Patients with Stable Angina Pectoris

PURPOSE

Statin therapy usually increases HDL-C levels. However, a paradoxical decrease in HDL-C levels after statin therapy is often seen in clinical settings. The relationship between a paradoxical decrease in HDL-C levels after statin therapy and adverse cardiovascular events in patients with stable angina pectoris (SAP) is not well understood. The purpose of this study was to analyze the relationship between paradoxical HDL-C decreases after statin therapy and major adverse cardiovascular events (MACEs) in patients undergoing percutaneous coronary intervention (PCI) for SAP.

METHODS

Between January 2006 and March 2015, 867 patients underwent PCI for SAP. Of them, we enrolled 209 patients who were newly started on statin therapy before PCI. We excluded patients who had started statin therapy earlier than 6 months before PCI, patients who had not started statin therapy after PCI, and patients who were diagnosed with acute coronary syndrome. They were divided into 2 groups according to the change in their HDL-C levels between baseline and 6 to 9 months after the index PCI: decreased HDL group after statin treatment (80 patients) and increased HDL group (129 patients). The primary end points were MACEs defined as a composite of all-cause death, nonfatal acute myocardial infarction, and target vessel revascularization (TVR).

FINDINGS

Using Kaplan-Meier analysis, the 7-year event rate for composite MACEs in the decreased HDL group was found to be higher than that for the increased HDL group (38% versus 24%, log-rank P = 0.02). TVR occurred more frequently in the decreased HDL group than in the increased HDL group (32% versus 12%, log-rank P = 0.01). With the use of multivariate analysis, changes in HDL-C levels after statin therapy indicated a significant inverse association with the increased risk of MACEs, (hazard ratio [HR] = 0.94; 95% CI, 0.92-0.97; P < 0.01). The incidence of MACEs was more strongly associated with ΔHDL than with ΔLDL. Moreover, BMS usage also independently predicted MACEs (HR = 2.18; 95% CI, 1.14-4.17; P < 0.01).

IMPLICATIONS

A paradoxical decrease in HDL-C levels after statin therapy might be a risk factor for MACEs, especially TVR, in patients with SAP.

Comparison of the Effect of Rosuvastatin 2.5 mg vs 20 mg on Coronary Plaque Determined by Angioscopy and Intravascular Ultrasound in Japanese With Stable Angina Pectoris (from the Aggressive Lipid-Lowering Treatment Approach Using Intensive Rosuvastatin for Vulnerable Coronary Artery Plaque [ALTAIR] Randomized Trial)

Diminishing yellow color, evaluated by coronary angioscopy, is associated with plaque stabilization and regression. Our aim was to assess the effect of aggressive lipid-lowering therapy with rosuvastatin on plaque regression and instability. Thirty-seven patients with stable angina or silent myocardial ischemia who planned to undergo elective percutaneous coronary intervention and had angioscopic yellow plaques of grade 2 or more were randomized to high-dose (group H, 20 mg/day, n = 18) or low-dose (group L, 2.5 mg/day, n = 19) rosuvastatin therapy for 48 weeks. Yellow plaque was graded on a 4-point scale of 0 (white) to 3 (bright yellow) by angioscopy, and plaque volume was determined by intravascular ultrasound for plaques with a length of 5 to 15 mm. Color and volume were assessed at baseline and after 48 weeks by the investigators blinded to the rosuvastatin dosage, and were compared between the 2 dosing groups. The level of low-density lipoprotein-cholesterol decreased from 130.3 ± 25.5 mg/dl to 61.7 ± 16.5 mg/dl (-50 ± 19%: high intensity) in group H (p <0.001) and from 130.9 ± 28.5 mg/dl to 89.7 ± 29.0 mg/dl (-30 ± 22%: moderate intensity) in group L (mean ± SD, p <0.001). The average color grade of yellow plaques decreased from 2.0 to 1.5 in group H (p <0.001) and from 2.0 to 1.6 in group L (p <0.001) after 48 weeks. Plaque volume decreased significantly in group H but not in group L. The percent change in plaque volume was significantly larger in group H than in group L (p = 0.005). In conclusion, both high-dose and low-dose rosuvastatin increased plaque stability. However, high-dose rosuvastatin was more effective than low-dose rosuvastatin in inducing plaque volume regression. Clinical Trial Registration No: UMIN-CTR, UMIN000003276.

Correlation between plaque vulnerability of aorta and coronary artery: an evaluation of plaque activity by direct visualization with angioscopy

This study investigated the relationship between the degree of atherosclerotic changes in the descending thoracic aorta (TA) and the coronary artery using angioscopy. Twenty-five consecutive patients undergoing angioscopy of the TA and coronary angiography were enrolled in this study. Participants were divided into three groups according to the angioscopic grading of the TA: white plaque group (W-group), yellow plaque group (Y-group) and intensive yellow, ruptured plaque with ulceration and/or thrombus group (RP-group). The maximum plaque grade, plaque score, number of yellow plaques, frequency of yellow-plaque grades by coronary angioscopy, and SYNTAX score by coronary angiography were evaluated. Brachial-artery pulse wave velocity and high-sensitivity C-reactive protein level tended to be higher in the RP-group than in the other groups, although the differences were not statistically significant. The SYNTAX score was significantly higher in the RP-group than in the W-group (W-group 4.0 ± 3.6 vs. RP-group 17.5 ± 10.0, P = 0.045). In addition, the angioscopic maximum plaque grade, plaque score, and number of yellow plaques in the RP-group were significantly higher than in the W-group (maximum plaque grade W-group 0.8 ± 0.4 vs. RP-group 1.8 ± 0.8, P = 0.026; plaque score W-group 1.0 ± 1.2 vs. RP-group 4.0 ± 1.4, P = 0.014; and number of yellow plaques W-group 1.0 ± 1.2 vs. RP-group 2.5 ± 0.5, P = 0.023). The yellow-plaque grade in the coronary artery was correlated significantly with the plaque grading of TA (P = 0.043). Our study suggests that the angioscopic progression of aortic atherosclerosis is closely associated with vulnerability to and the extent of coronary stenosis, indicating that vulnerability toward atherosclerotic plaque development occurs simultaneously in the coronary tree and systemic arteries.

Remodeling pattern is related to the degree of coronary plaque regression induced by pitavastatin: a sub-analysis of the TOGETHAR trial with intravascular ultrasound and coronary angioscopy

This study aimed to clarify the relationships between arterial remodeling patterns and plaque volume regression or stabilization. The TOGETHAR trial is a prospective open-label trial designed to assess coronary plaque regression and stabilization with multiple plaque imaging modalities following 52 weeks of pitavastatin treatment (2 mg/day). Coronary plaques were observed in 46 patients with both angioscopy and intravascular ultrasound at baseline and after 52 weeks of drug treatment. We divided these patients into three groups according to their remodeling indices (RI). Group P consisted of patients with a baseline RI >1.05, Group M of patients with a baseline RI of 0.95-1.05, and Group N of patients with a baseline RI <0.95 and then evaluated differences in coronary plaque volume changes and yellow grade among the three groups. In the positive remodeling group, whose remodeling index (RI) exceeded 1.05 at baseline, RI and percent atheroma volume (PAV) were significantly reduced (RI 1.14 ± 0.07 to 1.05 ± 0.10, p = 0.010, PAV 47.3 ± 8.3 to 45.3 ± 7.3 mm(3), p = 0.048). There was no relationship between baseline RI and the change in yellow grade of plaque. RI increased without significant change of PAV or a decrease in lumen volume in group N, with RI below 0.95 at baseline. Plaques with positive remodeling were more likely to have plaque volume regression by pitavastatin than those without in patients with coronary artery disease. Moreover, plaques with positive and negative remodeling were changed into those with intermediate remodeling by pitavastatin. Pitavastatin might induce not only plaque regression or stabilization, but also conformational normalization of vessel structure.

Angioscopic assessment of peri-stent contrast staining following drug-eluting stent implantation

BACKGROUND

Peri-stent contrast staining (PSS) has been recognized as a predictor of late stent thrombosis following drug-eluting stent (DES) implantation. However, the intravascular conditions at PSS sites remain unclear.

METHODS AND RESULTS

We evaluated 10 patients (median age 72 years, 80% male) with stable angina pectoris by coronary angioscopy. The patients had a total of 11 DES implantations (5 sirolimus-eluting stents; 4 paclitaxel-eluting stents; 2 everolimus-eluting stents) that showed PSS. Neointimal coverage (NIC), presence of thrombus, and yellow plaques underneath the stent were compared between PSS and non-PSS sites for each stent. NIC was graded as: grade 0, struts exposed; grade 1, struts bulging into the lumen, although covered; grade 2, struts embedded by neointima, but translucent; grade 3, struts fully embedded and invisible. Mean follow-up was 394±206 days (median: 289). NIC grade was lower at PSS sites (P=0.021) with 8 out of 11 stents (73%) having grade 0. Angioscopy detected a thrombus more frequently at PSS sites than at non-PSS sites (64% vs. 9%, P=0.012). Yellow plaques tended to be more significant at PSS sites than at non-PSS sites (82% vs. 45%, P=0.091).

CONCLUSIONS

The angioscopic findings suggest high thrombogenicity at PSS sites.

Ruptured plaque and large plaque burden are risks of distal embolisation during percutaneous coronary intervention: evaluation by angioscopy and virtual histology intravascular ultrasound imaging

AIMS

Slow flow and no flow phenomena have been associated with distal embolisation, especially of plaque debris, and with unfavourable clinical outcomes. However, patients at high risk of distal embolisation for whom distal protection might be beneficial have not been adequately identified. We examined the frequency of distal embolisation and its predicting factors, including both ACS and non-ACS patients.

METHODS AND RESULTS

Consecutive patients (n=98) with or without ACS who had received PCI with a filter-type distal protection device and successful angioscopic and VH-IVUS examination were prospectively enrolled. The presence of yellow plaque and plaque rupture was evaluated by angioscopy. Tissue classification and plaque burden was evaluated by VH-IVUS. Distal embolisation was evaluated by pathological examination of material collected in the filter. Distal embolisation of plaque debris was more frequently detected in patients with ACS (48% vs. 25%, p=0.02), in those with ruptured plaque (86% vs. 13%, p<0.001), in those with large (>75%) plaque burden (50% vs. 23%, p=0.006), and in those with grade 2/3 yellow plaque (52% vs. 7%, p<0.001), as compared to those without it.

CONCLUSIONS

The presence of ruptured yellow plaque and of large plaque burden, rather than the setting of ACS, was highly predictive of distal embolisation of plaque debris.

A higher colour grade yellow plaque was detected at one year after implantation of an everolimus-eluting stent than after a zotarolimus-eluting stent

OBJECTIVE

Neoatherosclerosis or atherosclerosis progression is one of the mechanisms of long-term stent failure. Yellow plaque detected by angioscopy has been associated with advanced atherosclerosis and the future risk of a coronary event. We compared the yellow colour of the stented segment between zotarolimus-eluting stents (ZES) and everolimus-eluting stents (EES) at 1 year after implantation.

DESIGN

Cross-sectional study.

PATIENTS

Consecutive patients underwent angioscopic examination 1 year after the implantation of ZES (n=45) or EES (n=45) at a de novo native coronary lesion.

MAIN OUTCOME MEASURES

The maximum yellow colour grade (grade 0-3) of the stented segment, maximum and minimum neointima coverage grade (grade 0-2) and the presence of thrombus were examined. The neointima heterogeneity index was calculated as maximum - minimum coverage grade.

RESULTS

Maximum yellow colour grade was higher in EES than in ZES (1.3±0.9 vs 0.4±0.8, p<0.001) and maximum (2.0±0.2 vs 1.2±0.5, p<0.001) and minimum (1.5±0.6 vs 0.7±0.5, p<0.001) coverage grade was higher in ZES than in EES. The neointima heterogeneity index was not different between ZES and EES (0.4±0.5 vs 0.5±0.6, p=0.42). The incidence of thrombus was very low and was not different between ZES and EES (2% vs 4%, p=0.55).

CONCLUSIONS

Although both ZES and EES had good healing with homogeneous neointima coverage and a low incidence of thrombus, EES had more advanced atherosclerosis as shown by the presence of higher grade yellow plaque than ZES at 1 year after implantation.

Chronic kidney disease and coronary artery vulnerable plaques

BACKGROUND AND OBJECTIVES

Chronic kidney disease (CKD) is a risk factor of cardiovascular disease. The number of yellow plaques is a predictor of future cardiovascular events. We assumed that CKD might raise the risk of cardiovascular events by increasing the number of yellow plaques. Therefore, we compared the number of yellow plaques between patients with and without CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Consecutive 136 patients with acute myocardial infarction who received percutaneous coronary intervention (PCI) and angioscopic examination were analyzed. The infarct-related artery was angioscopically examined. The number of yellow plaques, maximum yellow color grade of detected yellow plaques, and prevalence of disrupted yellow plaques in nonculprit segments were compared between patients with and without CKD.

RESULTS

The number of yellow plaques was significantly larger in CKD than in non-CKD patients (median [interquartile range]: 4.0 [2.0 to 6.0] versus 2.0 [1.0 to 4.0], P = 0.001). Maximum yellow color grade and prevalence of disrupted plaques in the nonculprit segments were not different between patients with and without CKD. Multivariate logistic regression analysis revealed CKD as an independent risk of multiple yellow plaques per vessel (odds ratio 3.49, 95% confidence interval 1.10 to 11.10, P = 0.03).

CONCLUSION

CKD was an independent risk factor of multiple coronary yellow plaques, suggesting that patients with CKD would have a higher risk of coronary events because they had more yellow plaques than patients without CKD.