Consensus document on the standard of coronary angioscopy examination and assessment from the Japanese Association of Cardiovascular Intervention and Therapeutics

Endovenous Angioscopy to Assess In Vivo Deep Venous Stenosis and Intervention: A Pilot Study

Direct visualization of deep venous pathology with the ability to assess responses to treatment could present a major advance in venous interventions. A pilot in vivo feasibility study assessing use of a clinical endoscope for venous angioscopy was performed in a swine model. The angioscopy technique enabled visualization of the vein wall, of venous trauma and stenosis, and of response to stent placement. The interface of the stent and vein wall, including at the edge of treated segments, was visualized with high resolution. The experimental setup required control of blood flow and saline irrigation for adequate visualization. No immediate adverse events were observed in this acute, nonsurvival study.

Comparison of Vessel Responses Following Combined Sirolimus-Eluting and Endothelial Progenitor Cell Stent and Ultra-Thin Sirolimus-Eluting Stent Implantation by Serial Optical Coherence Tomography and Coronary Angioscopy: A Multicenter Observational Study

A dual-therapy sirolimus-eluting and CD34+ antibody-coated Combo Stent (DTS) has been developed to enhance endothelization and capture endothelial progenitor cells; however, vessel responses following DTS implantation remain unclear. Therefore, we evaluated early- and mid-term intravascular characteristics of DTS using intravascular imaging modalities. This multicenter, prospective, observational study enrolled 88 patients (95 lesions) who underwent DTS (43 patients, 48 lesions) or sirolimus-eluting Orsiro stent (SES, 45 patients, 47 lesions) implantation. Serial optical coherence tomography (OCT) and coronary angioscopy (CAS) findings were compared between the groups at 1 and 12 months.The OCT findings were similar between the DTS and SES groups at 1 month, including the covered strut rate (84.21 ± 9.50% versus 80.56 ± 17.68%, p = 0.27). CAS findings were also comparable despite a more severe yellow coloration observed in the DTS group (p = 0.006). At 12 months, OCT findings revealed that the covered and adequate strut coverage (≥40 μm) rates were significantly higher (99.27 ± 0.95% versus 95.46 ± 5.56%, p <0.001 and 88.90 ± 10.15% versus 72.96 ± 16.48%, p <0.001) and neointimal thickness was significantly thicker (152.16 ± 70.31 versus 84.39 ± 29.80 μm, p <0.001) in DTS than in SES. The malapposed strut rate was significantly higher in SES than in DTS (0.04 ± 0.18% versus 0.82 ± 1.87%, p = 0.018). CAS revealed that the yellow coloration (p = 0.049) and subclinical intrastent thrombus (p = 0.019) were less severe in DTS than in SES at 12 months. In conclusion, DTS provided better advantages regarding strut coverage and plaque stabilization compared to SES. However, given the observational nature of this study, further randomized controlled trials are needed to confirm these findings.

Serial Change and Clinical Impact of Irregular Protrusion in Lesions With Chronic Coronary Syndrome

BACKGROUND

The changes over time and effects on long-term clinical outcomes beyond 1 year of irregular protrusion (IP) in chronic coronary syndrome (CCS) remains unclear.

AIMS

This study aimed to assess the time-dependent change and long-term clinical impact of IP in CCS lesions.

METHODS

This study was a post hoc analysis of COLLABORATION study, which was a multicenter, prospective, observational study conducted from July 2018 to February 2020, assessing 1- and 12-month serial vessel responses after stent implantation using OCT and coronary angioscopy. Time-dependent change in the presence of IP was evaluated using the serial OCT examinations. The cumulative 3-year incidence of TLR was compared between the lesions with and without IP, as well as between those with and without residual IP at 1 month.

RESULTS

Among 107 lesions, IP was detected in post-OCT pullbacks in 38 (35.5%) lesions. Out of the 38 lesions, IP remained in 9 (23.7%) lesions at 1 month and existed in 2 (5.3%) lesions at 12 months. The cumulative 3-year incidence of TLR was significantly higher in IP group than in non-IP group (13.6% vs. 3.0%, p = 0.04). Similarly, it was significantly higher in lesions with residual IP at 1 month than those without (33.3% vs. 4.3%, p < 0.01). All residual IP at 1 month were composed of angioscopic yellow plaques and red thrombi.

CONCLUSIONS

The presence of IP decreased over time, but approximately one-fourth of IP remained at 1 month. IP and residual IP at 1 month were important post-stent OCT findings leading to long-term TLR in patients with CCS.

Impact of baseline yellow plaque assessed by coronary angioscopy on vascular response after stent implantation

BACKGROUND

The relationship between baseline yellow plaque (YP) and vascular response after stent implantation has not been fully investigated.

METHODS

This was a sub-analysis of the Collaboration-1 study (multicenter, retrospective, observational study). A total of 88 lesions from 80 patients with chronic coronary syndrome who underwent percutaneous coronary intervention were analyzed. Optical coherence tomography (OCT) and coronary angioscopy (CAS) were serially performed immediately and 11 months after stent implantation. YP was defined as the stented segment with yellow or intensive yellow color assessed by CAS. Neoatherosclerosis was defined as a lipid or calcified neointima assessed by OCT. OCT and CAS findings at 11 months were compared between lesions with baseline YP (YP group) and lesions without baseline YP (Non-YP group).

RESULTS

Baseline YP was detected in 37 lesions (42 %). OCT findings at 11 months showed that the incidence of neoatherosclerosis was significantly higher in the YP group (11 % versus 0 %, p = 0.028) and mean neointimal thickness tended to be lower (104 ± 43 μm versus 120 ± 48 μm, p = 0.098). CAS findings at 11 months demonstrated that the dominant and minimum neointimal coverage grades were significantly lower (p = 0.049 and P = 0.026) and maximum yellow color grade was significantly higher (p < 0.001) in the YP group.

CONCLUSIONS

Baseline YP affected the incidence of neoatherosclerosis as well as poor neointimal coverage at 11 months after stent implantation.

Relation of Thrombolysis in Myocardial Infarction Frame Count to Invasively Measured Coronary Physiologic Indexes

In the international guidelines, higher thrombolysis in myocardial infarction frame count (TFC) is indicated as evidence of coronary microvascular dysfunction (CMD). However, the association of TFC with invasively measured coronary physiologic parameters such as coronary flow reserve (CFR) and index of microcirculatory resistance (IMR) remains unclear. Patients without significant epicardial coronary lesions underwent invasive coronary physiologic assessment using a thermodilution method in the left anterior descending artery. Corrected TFC (cTFC) was evaluated on coronary angiography. The cut-off values of CFR and IMR were defined as ≤2.0 and >25, and patients with abnormal CFR and/or IMR were defined as having CMD. This study aimed to assess whether cTFC >25, a cut-off value in the guidelines, was diagnostic of the presence of CMD. Of the 137 patients, 34 (24.8%) and 32 (23.3%) had cTFC >25 and CMD, respectively. The rate of CMD was not significantly different between patients with and without cTFC >25. cTFC was weakly correlated with at rest and hyperemic mean transit time and IMR, whereas no significant correlation was observed between cTFC and CFR. The receiver operating characteristic curve analysis showed the poor diagnostic ability of cTFC for abnormal CFR and IMR and the presence of CMD. In conclusion, in patients without epicardial coronary lesions, cTFC as a continuous value and with the cut-off value of 25 was not diagnostic of abnormal CFR and IMR and the presence of CMD. Our results did not support the use of cTFC in CMD evaluation.

Identification of post-procedural optical coherence tomography findings associated with the 1-year vascular response evaluated by coronary angioscopy

Optical coherence tomography (OCT) provides higher resolution intravascular imaging and allows detailed evaluations of stent implantation sites post-percutaneous coronary intervention (PCI). Coronary angioscopy (CAS) can evaluate the vascular response after drug-eluting stent (DES) implantation. The post-PCI OCT findings that are associated with the CAS 1-year vascular response have not been known. We enrolled 168 lesions from 119 patients who underwent OCT-guided PCI using DES and follow-up CAS observation at 1 ± 0.5 year from August 2012 to December 2019. Outcome measures were sufficient neointimal coverage (NIC) defined as stent struts embedded in the neointima, subclinical intrastent thrombus, and vulnerable stented segments defined as those with angioscopic yellow or intensive yellow color 1 year after PCI. We identified the post-PCI OCT findings associated with these CAS findings. Sufficient NIC, subclinical intrastent thrombus, and vulnerable stented segment were detected in 85 lesions (51%), 47 lesions (28%), and 54 lesions (32%), respectively. A multivariate analysis demonstrated that malapposed struts were negatively associated with sufficient NIC (odds ratio 0.87; 95% CI 0.76-0.99; p = 0.029). However, no specific OCT findings immediately after PCI were associated with subclinical intrastent thrombus or vulnerable stented segment. Malapposition immediately after PCI was negatively associated with sufficient NIC at 1 year even without associations between post-PCI OCT findings and subclinical intrastent thrombus or vulnerable stented segment.

Angioscopic findings 1 year after percutaneous coronary intervention for chronic total occlusion

BACKGROUND

Chronic total occlusion (CTO) is a high-risk factor for stent thrombosis, but little is known about the difference in neointimal healing between CTO and non-CTO lesions regarding implanted stents. We investigated factors affecting neointimal healing after stent implantation for CTO and non-CTO lesions using angioscopy.

METHODS

We retrospectively evaluated 106 stents in 85 consecutive patients between March 2016 and July 2020. Their average age was 68 ± 11 years, and participants (73 male and 12 female) underwent follow-up angiography and angioscopy 1 year after percutaneous coronary intervention (PCI). The stents (n = 106) were divided into three groups according to the lesion status at the previous PCI: CTO (n = 17), acute coronary syndrome (ACS) (n = 35), and stable coronary artery disease without CTO or non-CTO (n = 54).

RESULTS

The neointimal stent coverage grade was significantly lower in the CTO and ACS groups than in the non-CTO group (0.4 ± 0.5, 0.9 ± 0.8, and 1.4 ± 0.8, respectively, p < 0.001). Thrombi were significantly more frequent in CTO and ACS than in non-CTO (71 %, 51 %, and 15 %, respectively, p < 0.001). The yellow grade in CTO was comparable to that in ACS but significantly higher in CTO than in non-CTO (CTO vs. ACS vs. non-CTO 1.5 ± 0.7, 1.4 ± 0.6, and 0.9 ± 0.7, respectively, p = 0.007).

CONCLUSIONS

Delayed healing occurs in stents implanted for CTO lesions. Longer dual-antithrombotic therapy may be beneficial.

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.

Novel Endovascular Therapy, AGET, for In-Stent Occlusions in Iliac and Femoropopliteal Arteries

Catheter-directed intra-arterial thrombolysis (CDT) is useful for not only patients with acute limb ischemia but also those with chronic total occlusions (CTOs) of the lower extremity arteries. However, it is difficult to determine whether CTO lesions have significant thrombi, which can be treated by CDT, or not in a clinical setting. Angioscopy can accurately detect thrombi. We investigated the clinical impact of angioscopy guided endovascular therapy following thrombolysis (AGET) for in-stent occlusions (ISOs) in iliac or femoropopliteal arteries.We performed AGET in 7 patients with ISOs whose occlusion duration was less than 1 year. We performed angioscopy to evaluate the area of the thrombi after a successful wire crossing of an ISO lesion. In addition, we performed biopsies of ISO lesions to confirm whether the angioscopic findings coincided with the histopathological findings at 20 sites. We selectively performed a continuous infusion of urokinase using a fountain infusion catheter for ISO lesions. The next day, we evaluated the lesion flow and performed intervention only at the plaque stenosis site if necessary.AGET could achieve TIMI 3 flow in all patients, and preserved a 1-year patency in 5 patients (71.4%). The angioscopic findings of thrombi and plaque perfectly coincided with the histopathological findings.In conclusion, this new endovascular therapy technique, AGET, was observed to be feasible and safe for iliac or femoropopliteal artery ISO lesions.

Comparison of 1-Month and 12-Month Vessel Responses Between the Polymer-Free Biolimus A9-Coated Stent and the Durable Polymer Everolimus-Eluting Stent

BACKGROUND

A polymer-free biolimus A9-coated stent (PF-BCS) may achieve better arterial healing than a durable polymer drug-eluting stent owing to its polymer-free feature.

METHODS AND RESULTS

This multicenter, prospective, observational study enrolled 105 patients (132 lesions) who underwent PF-BCS (51 patients, 71 lesions) or durable polymer everolimus-eluting stent (DP-EES, 54 patients, 61 lesions) implantation. Serial coronary angioscopy (CAS) and optical coherence tomography (OCT) examinations were performed at 1 and 12 months, and the serial vessel responses were compared between PF-BCS and DP-EES. The primary outcome measure was the incidence of subclinical intrastent thrombus on CAS. The secondary outcome measures were: adequate strut coverage (≥40 μm) on OCT and maximum yellow color grade on CAS. The incidence of thrombus was high at 1 month (100% vs. 93%, P=0.091), but decreased at 12 months (18% vs. 25%, P=0.56), without a significant difference between PF-BCS and DP-EES. The adequate strut coverage rate was significantly higher (84±14% vs. 69±22%, P<0.001) and yellow color was significantly less intense (P=0.012) at 12 months in PF-BCS than in DP-EES; however, they were not significantly different at 1 month (adequate strut coverage: 47±21% vs. 50±17%, P=0.40; yellow color: P=0.99).

CONCLUSIONS

Although the thrombogenicity of PF-BCS was similar to that of DP-EES, the adequate coverage and plaque stabilization rates of PF-BCS were superior to those of DP-EES at 12 months.

Early- and Middle-Phase Angioscopic Assessment of Arterial Healing Following Current Drug-Eluting Stent Implantation in Patients With Acute Coronary Syndrome

Background: Drug-eluting stents (DESs) have been widely used for the treatment of acute coronary syndrome (ACS). However, there are few reports on early- and middle-phase arterial repair after DES implantation in ACS patients. Methods and Results: Coronary angioscopy (CAS) findings covering the early and middle phases (mean [±SD] 4±1 and 10±2 months, respectively) of arterial healing after second- and later-generation DES placement between May 2009 and January 2020 were extracted from the Kansai Rosai Hospital Cardiovascular Center database. Neointimal coverage (NIC), yellow color intensity, and the incidence of thrombus adhesion were compared between ACS and chronic coronary syndrome (CCS) in the early (54 stents of 47 lesions, 38 ACS patients; 86 stents of 70 lesions, 52 CCS patients) and middle (179 stents of 154 lesions from 136 ACS patients; 459 stents of 374 lesions from 287 CCS patients) phases. In the early phase, NIC, the incidence of thrombus adhesion (ACS, 39.1%; CCS, 38.0%), and maximum yellow color grade were similar between the 2 groups. In the middle phase, although the maximum yellow color grade was significantly higher in the ACS group (P=0.013), NIC and the incidence of thrombus adhesion (ACS, 24.6%; CCS, 23.4%) were similar in the 2 groups. Conclusions: Arterial healing assessment with CAS showed that NIC and the incidence of thrombus adhesion after DES implantation were similar between ACS and CCS patients.