Fundamental wire technique and current standard strategy of percutaneous intervention for chronic total occlusion with histopathological insights

Recent Advances in Coronary Chronic Total Occlusions

Coronary chronic total occlusions (CTOs) have been a point of interest of the medical community for the last decade. The natural history of CTOs was for a long time unknown, as the presence of a single CTO was the most frequent cause for the exclusion of patients from randomized controlled trials (RCTs). Recent CTO RCTs have failed to show any benefit in terms of hard endpoints as major adverse cardiovascular events, but have shown a significant improvement in quality of life, as well in the frequency of angina; however, these studies are characterized by the limitation of the short duration of their follow-up period. Real-world data from observational studies indicate a significant improvement in cardiovascular death and overall mortality, suggesting that the results depend on the duration of the follow-up, and not on the procedure per se. The aim of the current review is to summarize all the existing RCTs, and to analyze the most important registries, as well as to present the current development of techniques to boost the successful interventional treatment of CTOs.

New Frontiers in Antegrade Wiring From the Asia Pacific Chronic Total Occlusion Club

Antegrade wiring (AW) is the prevailing chronic total occlusion (CTO) crossing technique. For proximal cap ambiguity, the Global CTO consensus group uses the "anatomy dictates strategy" method: 1) intravascular ultrasound; 2) move the cap; or 3) retrograde. For CTO body crossing, anatomy dictates 4 strategies: 1) CTOs with tapered stump-loose tissue tracking; 2) CTOs with clear intimal path-intentional intimal tracking with 3-dimensional (3D) wiring; 3) CTOs without a clear intimal path-intentional intimal tracking with intermediate penetration wire; and 4) the "long plus CTOs"-intentional subintimal wiring. The new angiographic 3D antegrade puncture technique from the APCTO (Asia Pacific Chronic Total Occlusion) Club is presented for distal cap puncture. angiographic 3D antegrade puncture technique can be used as a 3D wiring technique as well as an antegrade dissection and re-entry technique. Based on these new frontiers, we have updated our APCTO algorithm in this paper. This update can form a basis for research and training.

Role of pre-procedure CCTA in predicting failed percutaneous coronary intervention for chronic total occlusions

Purpose

This study aimed to identify major lesion characteristics of chronic total occlusions (CTOs) that predict failed percutaneous coronary intervention (PCI) using pre-procedure coronary computed tomography angiography (CCTA) in combination with conventional coronary angiography (CCA).

Methods

Consecutive patients with at least one CTO of the native coronary arteries received CCTA and CCA-guided PCI, with computed tomography performed before or during PCI.

Results

A total of 76 patients with CTO were included in this study. 76 patients were divided into successful and failed PCI groups based on their PCI outcome. There were 62 (81.58 %) patients in the successful PCI group and 14 (18.42 %) in the failed PCI group. The occlusion length ≥20 mm, ostial or bifurcation lesions, negative remodeling, microchannels, and good collateral vessels were the CCTA morphologic parameters associated with PCI outcome (P<0.05). In addition, the blunt stump, occlusion length ≥20 mm, and ostial or bifurcation lesions, were the CCA morphologic parameters associated with PCI outcome (P<0.05). The multivariate regression model showed that the three independent negative predictors: blunt stump on CCA (OR: 0.63; 95 % CI: 0.23-0.98; p =0.048), occlusion length ≥20 mm on CCTA (OR: 0.37; 95 % CI: 0.32-0.71; p <0.001) and negative remodeling on CCTA (OR: 0.26; 95 % CI: 0.28-0.44; p <0.001).

Conclusion

Our study demonstrated that combining CCTA and CCA morphologic characteristics could improve PCI outcome prediction in patients with CTO compared to CCTA morphologic features alone.

Research frontiers and hotspots of coronary chronic total occlusion: A bibliometric analysis

By analyzing the relevant literature, we can accurately grasp the current status of diagnosis and treatment of chronic total occlusion of coronary artery, and clarify the development trend, research frontiers and hotspots of this disease. A literature search with "chronic total occlusion" as the title was performed in the Web of Science database. The title, author, abstract, keywords, institution, publication, country, reference, and other endnotes of the selected literature were exported in the form of text. The author, country, institution, and keywords of the literature were analyzed through Citespace and VOSviewer. The United States has the highest proportion of articles. The institution with the largest number of publications in this field is the Minneapolis Heart Institute Foundation. Brilakis Emmanouil S is the author with the most published articles. The journal system with the largest number of articles in this field is Cardiac Cardiovascular Systems. The keywords with the highest frequency are "chronic total occlusion," "percutaneous coronary intervention," "recanalization," and "revascularization." The burst detection analysis of hot keywords shows that "algorithm," "management," and "mortality" are the research hotspots in this field in recent years. At present, the research on this disease mainly focuses on the opening of occluded coronary arteries through various treatment methods. In the near future and the next few years, the research hotspots may be the scoring system algorithms for the treatment of chronic total occlusion of coronary artery and the management strategies for patients.

Determinants of One-Year Outcome After Successful Percutaneous Coronary Intervention for Chronic Total Occlusion; Insight from Japanese CTO-PCI Expert Registry

Although outcomes have improved with new-generation drug-eluting stents, few reports have analyzed the risk factors associated with chronic outcomes of chronic total occlusion (CTO)-percutaneous coronary intervention (PCI). This study aimed to investigate the independent risk factors for target lesion revascularization (TLR) and major adverse cardiac and cerebrovascular events (MACCEs) after CTO-PCI using Japanese multicenter data. A total of 3,666 patients, who underwent CTO-PCI and completed a 1-year follow-up, registered at the Japanese CTO-PCI Expert Registry from 2014 to 2019, were examined. The primary outcome was defined as TLR, and the secondary outcome was MACCEs at the 1-year follow-up. TLRs and MACCEs occurred in 175 (4.8%) and 524 (14.3%) patients, respectively. Multivariate logistic regression analysis demonstrated that in-stent occlusion (ISO) (odds ratio [OR] 2.604, 95% confidence interval [CI] 1.695 to 4.001), hemodialysis (OR 1.784, 95% CI 1.062 to 2.997), diabetes mellitus with insulin use (OR 1.741, 95% CI 1.060 to 2.861), moderate-to-severe calcification (OR 1.726, 95% CI 1.197 to 2.487), and the right coronary artery as the target vessel (OR 1.468, 95% CI 1.018 to 2.117) were significantly associated with TLR. Hemodialysis (OR 2.214, 95% CI 1.574 to 3.113), ISO (OR 1.499, 95% CI 1.127 to 1.993), arteriosclerosis obliterans (OR 1.414, 95% CI 1.074 to 1.863), and multivessel disease (OR 1.356, 95% CI 1.117 to 1.647) were significantly associated with MACCEs. One-year outcomes of new-generation drug-eluting stents for CTO-PCI were favorable, and ISO as a lesion factor and hemodialysis as a patient factor were strongly associated with TLR and MACCEs, respectively.

Mechanisms of Medial Wall Thinning in Chronic Total Occlusion

BACKGROUND

The success rate of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) is lower and the risk for complications higher compared with other non-CTO PCI. Although interventionalists focus on intimal plaque characteristics, the coronary media is an important (especially for techniques involving antegrade dissection and re-entry) but poorly understood structure in CTO PCI.

OBJECTIVES

The aim of the present study was to investigate coronary medial wall thinning in CTO lesions and determine how this thinning might affect CTO PCI.

METHODS

A total of 2,586 sections were investigated, from arteries with evidence of CTO from 54 subjects (1,383 sections) and arteries without evidence of CTO from 54 subjects with non-coronary-related deaths (1,203 sections) after matching for age, gender, body weight, and body height.

RESULTS

The medial thickness in subjects with CTO was lower than that in those with non-coronary-related death (P < 0.001). In subjects with CTO, CTO lesions had thinner medial walls compared with those with lower luminal narrowing (P < 0.001). At the CTO distal segments, the 6- to 12-mm distal segment from the distal end of the CTO had significantly less luminal narrowing (P < 0.001), and similar medial thickness, compared with the distal end of the CTO. Immunohistochemical analysis revealed that short-duration CTO had more cleaved caspase-3-positive cells in media and had significantly more CD3+, CD4+, CD8+, and CD4+CD28null T cells compared with long-duration CTO.

CONCLUSIONS

CTO lesions demonstrated coronary medial thinning compared with non-CTO lesions. Further investigation of the cause-and-effect relationship among inflammation, apoptosis, and coronary medial wall thinning is warranted in future mechanistic studies.

Coronary Chronic Total Occlusion Revascularization: When, Who and How?

Coronary chronic total occlusions (CTO) are an increasingly frequent entity in clinical practice and represent a challenging percutaneous coronary intervention (PCI) scenario. Despite data from randomized trials that have not yet demonstrated a clear benefit of CTO recanalization, the widespread of CTO-PCI has substantially increased. The improvement in operators' techniques, equipment, and training programs has led to an improvement in the success rate and safety of these procedures, which will represent an important field of future development of PCI. The present review will summarize clinical outcomes and technical and safety issues of CTO revascularization with the aim to guide clinical daily cath-lab practice.

A case report on intravascular lithotripsy to facilitate retrograde wire passage from the subintimal to the luminal space in a calcified chronic total occlusion

Background

Severe calcifications are a major reason for failures in chronic total coronary occlusions, as they can obstruct the wire passage both in the antegrade and retrograde technique.

Case summary

The proximal occlusion of the left anterior descending artery in a 75-year-old man presented with a completely concentric calcified ring all along the segment proximal to the occlusion. The antegrade wire could not pass the calcified occlusion, and in a retrograde approach via the right posterior descending artery the retrograde wire was not able to enter the lumen from a subintimal position outside of the calcified ring. Intravascular lithoplasty in the proximal segment led to a crack in this ring to enable the same retrograde wire now to pass into the true lumen with then successful conclusion of the case. Intravascular ultrasound demonstrated the modification of the calcified ring and the passage of the wire with only a very short subintimal pathway.

Discussion

Intravascular lithoplasty is a new option to modify severely calcified vessel segments to facilitate the reverse controlled antegrade and retrograde tracking approach. In the present case, this helped to avoid a long subintimal pathway and preserved the vessel anatomy.

CTO and Bifurcation Lesions: An Expert Consensus From the European Bifurcation Club and EuroCTO Club

Knowledge in the field of bifurcation lesions and chronic total occlusions (CTOs) has progressively improved over the past 20 years. Therefore, the European Bifurcation Club and the EuroCTO Club have decided to write a joint consensus statement to share general knowledge and practical approaches in this complex field. When percutaneously treating CTOs, bifurcation lesions with relevant side branches (SBs) are found in approximately one-third of cases (35% at the proximal cap, 38% at the distal cap, and 27% within the CTO body). Occlusion of a relevant SB is not rare and has been shown to be associated with procedural complications and adverse outcomes. Simple bifurcation rules are very useful to prevent SB occlusion, and provisional SB stenting is the recommended approach in the majority of cases: protect the SB as soon as possible by wiring it, respect the fractal anatomy of the bifurcation by using the 3-diameter rule, and avoid using dissection and re-entry techniques. A systematic 2-stent approach can be used if needed or sometimes to connect both branches of the bifurcation. The retrograde approach can be very useful to save a relevant SB, especially in the case of a bifurcation at the distal cap or within the CTO body. Intravascular ultrasound is also a very important tool to address the difficulties with bifurcations at the proximal or distal cap and sometimes also within the CTO segment. Double-lumen microcatheters and angulated microcatheters are crucial tools to resolve access difficulties to the SB or the main branch.

Antegrade versus Retrograde Approach for Recanalization of Ostial or Stumpless Coronary Chronic Total Occlusion

Purpose

This research aimed to evaluate the procedural and in-hospital clinical outcomes of percutaneous coronary intervention (PCI) for ostial or stumpless chronic total occlusion (CTO) utilizing both the antegrade-only and retrograde approaches.

Methods

A comprehensive retrospective examination was conducted on the procedural and in-hospital clinical outcomes of 89 consecutive patients subjected to ostial or stumpless CTO PCI at our institution between April 2015 and October 2022.

Results

The antegrade-only technique demonstrated a superior technical success rate (92.0% vs 71.9%, p = 0.041) and procedural success rate (92.0% vs 68.8%, p = 0.022) in comparison to the retrograde approach (RA). The RA group presented a notably elevated Japanese-CTO (J-CTO) score relative to the antegrade-only approach group (2.45±0.73 vs 1.64±0.70, p < 0.001). The antegrade-only approach group manifested an increased frequency of microchannels at the proximal stump relative to the RA group (56.0% vs 10.9%, p < 0.001). In-hospital major adverse cardiac events (MACE) and in-hospital myocardial infarction (MI) were observed more prevalently in the RA group (18.8% vs 0, p = 0.003; 15.6% vs 0, p = 0.008; respectively). A J-CTO score below 2 and the manifestation of microchannels at the proximal stump were identified as predictors for successful antegrade-only approach PCI for ostial or stumpless CTO (OR: 2.79 [95% CI: 1.92-5.03, P =0.003]; OR: 2.89 [95% CI: 1.32-6.03, P =0.001]; respectively).

Conclusion

Relative to RA PCI for ostial or stumpless CTO, the antegrade-only approach is utilized for less complex CTO lesions and is associated with a diminished probability of in-hospital MACE.

Intravascular Ultrasound-Guided Percutaneous Coronary Intervention: Practical Application

Why is intravascular ultrasounography (IVUS) highly encouraged for the practical guidance of percutaneous coronary intervention (PCI)? First reason is to understand the mechanism of revascularization. Even if stenoses look similar in angiography, the pathophysiology could be different in each lesion. Second reason is to anticipate possible complications in advance. With prediction and appropriate preparation, most complications can be avoided or managed calmly when they occur. Third reason is to optimize PCI results with interactive IVUS use during the procedure. All these are essential to maximize the results of revascularization while minimizing acute complications, ultimately leading to improved long-term clinical outcomes.

Advances in Intravascular Ultrasound

Since its inception, intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have played a significant role in evaluating the pathophysiology of coronary artery disease (CAD) guiding the interventional and medical management of CAD improving outcomes in patients. Although the benefits of each of these modalities have been proven, due to some limitations, no single intravascular imaging technique has been proven to provide a detailed and complete evaluation of all CAD lesions. The use of different intravascular imaging modalities sequentially may lead to complications, which are cumbersome, consume time, and add financial burden to the patient. Recently, hybrid imaging catheters that combine OCT and IVUS benefits have been developed to limit these problems. Intravascular imaging techniques we are using currently have some drawbacks that hinder accurate assessment of plaque morphology and pathobiology as demonstrated in many histological studies, causing difficulty in identifying high-risk plaques. To overcome these limitations, great efforts have been put into developing hybrid, dual-probe catheters by combining imaging modalities to get an accurate analysis of plaque characteristics, and high-risk lesions. At present, many dual-probe catheters are available including combined IVUS-OCT, near-infrared spectroscopy-IVUS that is available commercially, the OCT-near infrared fluorescence (NIRF) molecular imaging, IVUS-NIRF, and combined fluorescence lifetime-IVUS imaging. Application of this combined multimodal imaging in clinical practice overcomes the limitations of standalone imaging and helps in providing a comprehensive and accurate visualization of plaque characteristics, composition, and plaque biology. The present article summarizes the advances in hybrid intravascular imaging, analyses the technical hindrances that should be known to have a use in the different clinical circumstances, and the till date shreds of evidence available from their first clinical application aiming to bring these modalities into the limelight and their potential role in the study of CAD.

Current clinical use of intravascular ultrasound imaging to guide percutaneous coronary interventions (update)

There are 3 main reasons to promote the practical application of IVUS during PCI. First reason is to understand the mechanism of vessel dilatation. Even if angiographic stenoses are similar, their pathophysiologies are different. It is important to understand what can happen by dilating coronary artery with balloon/stent, and to develop a strategy to achieve the maximum effect. Second reason is to anticipate possible complications and to reduce them in advance. In that case, we can deal with it as calmly as possible. Third reason is to validate the PCI performed. This should lead to further improvements of the procedures, which in turn will lead to improved short- and long-term prognosis. Then, high-quality PCI could be possible. This review summarizes the standard usage of IVUS in routine clinical practice and the use of IVUS in specific situations, especially complex lesions.

Reshaping the Ventricle From Within: MIRTH (Myocardial Intramural Remodeling by Transvenous Tether) Ventriculoplasty in Swine

MIRTH (Myocardial Intramural Remodeling by Transvenous Tether) is a transcatheter ventricular remodeling procedure. A transvenous tension element is placed within the walls of the beating left ventricle and shortened to narrow chamber dimensions. MIRTH uses 2 new techniques: controlled intramyocardial guidewire navigation and EDEN (Electrocardiographic Radial Depth Navigation). MIRTH caused a sustained reduction in chamber dimensions in healthy swine. Midventricular implants approximated papillary muscles. MIRTH shortening improved myocardial contractility in cardiomyopathy in a dose-dependent manner up to a threshold beyond which additional shortening reduced performance. MIRTH may help treat dilated cardiomyopathy. Clinical investigation is warranted.

Recanalisation of coronary chronic total occlusions

Percutaneous treatment of coronary chronic total occlusions (CTO) has advanced greatly since its advent in the late 1970s through the development of dedicated wires and microcatheters, the improved skills of highly experienced operators and the adoption of new sophisticated strategies to guide procedural planning. The contemporary procedural success rate is 80-90% with a reduction in complications. Although there has been no improvement in prognosis in randomised trials to date, they, and other controlled registries of thousands of patients, confirm the pivotal role of CTO recanalisation in the treatment of angina and dyspnoea and an improvement in quality of life. Despite this evidence, CTO recanalisation is grossly underutilised. This review reports a detailed overview of the history, indications and treatment strategies for CTO recanalisation and hopes to increase interest among new, and especially young, operators in this demanding, rapidly evolving field of interventional cardiology.

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.

Non-Invasive Evaluation of Patients Undergoing Percutaneous Coronary Intervention for Chronic Total Occlusion

Background: As percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) gains wider acceptance as a therapeutic option for coronary artery disease, the importance of appropriate patient selection has increased. Although cardiovascular magnetic resonance imaging (MRI) allows segmental and quantitative analyses of myocardial ischemia and scar transmurality, it has limitations, including contraindications, cost, and accessibility. This study established a non-invasive method to evaluate patients undergoing CTO-PCI using two-dimensional speckle-tracking echocardiography (2D-STE). Methods: Overall, we studied 55 patients who underwent successful CTO-PCI. Cardiovascular MRI and 2D-STE were performed before and 8 ± 2 months after CTO-PCI. Segmental findings of strain parameters were compared with those obtained with late gadolinium enhancement and stress-perfusion MRI. Results: With a cutoff of −10.7, pre-procedural circumferential strain (CS) showed reasonable sensitivity (71%) and specificity (73%) for detecting segments with transmural scar. The discriminatory ability of longitudinal strain (LS) for segments with transmural scar significantly improved during follow-up after successful CTO-PCI in the territory of the recanalized artery (area under the curve (AUC) 0.70 vs. 0.80, p < 0.001). LS accuracy was lower than that of CS at baseline (AUC 0.70 vs. 0.79, p = 0.048), and was increased at follow-up (AUC 0.80 vs. 0.82, p = 0.81). Changes in myocardial perfusion reserve from baseline to follow-up were significantly associated with those in LS but not in CS. Conclusions: Use of 2D-STE may allow the non-invasive evaluation of patients undergoing CTO-PCI to assess the indication before the procedure and treatment effects at follow-up.

[Technical armamentarium for chronic total occlusion of coronary vessels]

Percutaneous revascularization of chronic total occlusion (CTO) of coronary vessels represents a major challenge for contemporary interventional cardiologists. In the last decade there has been an unprecedented effort towards the standardization of revascularization procedures for CTO of coronary vessels. This endeavour has been possible by virtue of the growing interest of various cardiological societies for this patient group. Along with supportive endovascular technologies and percutaneous devices specifically dedicated to this interventional target, the increasing experience of interventionalists enabled continuously growing success for revascularization of CTO of coronary vessels. This review article highlights the currently available tools as well as technologies, techniques and strategies for the percutaneous recanalization of CTO of coronary vessels.

Antegrade versus retrograde techniques for Chronic Total Occlusions (CTO): a review and comparison of techniques and outcomes

Introduction: As the field of chronic total occlusion percutaneous coronary intervention has evolved, technical approaches have evolved and been refined.Areas covered: In this review, we discuss the major techniques utilized in modern CTO PCI including antegrade wiring, antegrade dissection reentry, retrograde wiring, and retrograde dissection reentry. Retrograde techniques have been extensively studied in comparison to antegrade techniques. Retrograde techniques have contributed to increases in CTO PCI success rates and are generally used in higher complexity lesions. Observational data ssuggestincreased sshort-termcomplications in procedures requiring the use of retrograde techniques; however, llong-termCTO PCI durability and patient outcomes have been shown to be similar among procedures using antegrade only versus retrograde techniques.Expert opinion: Retrograde techniques play a vital role in the technical success of CTO PCI, particularly among more complex lesions and in patients with high burdens of comorbidities. Increases in procedural safety with equipment iteration and in the use of adjunctive imaging will play an important role in the selection of appropriate retrograde conduits and the overall success rates of CTO PCI.

Impact of Advanced Technique on Improvement in the Retrievable Inferior Vena Cava Filter Retrieval Rate

BACKGROUND

It is recommended to remove retrievable inferior vena cava filters (r-IVCFs) when they are no longer needed because their presence may give rise to serious complications related to prolonged placement of the filter. An advanced filter retrieval technique may help improve the retrieval rate.

METHODS AND RESULTS

107 consecutive patients (mean age; 61±18 years, male 53%) in whom r-IVCF retrieval was attempted were prospectively enrolled between April 2012 and December 2018. The frequently used advanced techniques were sling technique and biopsy forceps dissection technique. Retrieval success was 75% with standard retrieval technique alone; however, the overall retrieval success rate improved to 98% with advanced techniques. We observed few serious complications related to the retrieval procedure. Logistic multivariate analysis identified prolonged indwelling time (P=0.0011) and embedded hook in the caval wall (P=0.0114) as independent predictors, and the cutoff value for the indwelling time for requirement of advanced technique was 80 days.

CONCLUSIONS

Advanced retrieval techniques helped improve the retrieval rate without serious complications. We may need to consider the referral of patients to centers with expertise in advanced retrieval techniques when the indwelling time is >80 days, and pre-retrieval CT image shows a hook embedded in the vessel wall.

Thrombotic Lesions are Associated with Poor Outcomes after Endovascular Treatment in Patients with Non-Acute Aortoiliac Total Occlusions

Aim: The post-endovascular treatment outcomes of thrombotic lesions remain unclear. This study aimed to investigate the effects of thrombotic lesions on post-endovascular treatment outcomes in patients with non-acute aortoiliac total occlusions.

Methods: This subanalysis of a multicenter prospective observational registry study included patients from 64 institutions in Japan between April 2014 and April 2016. A total of 346 patients (394 limbs; median age, 72 years), including 186 men, underwent endovascular treatment for non-acute aortoiliac total occlusions and were included. The patients were classified as having thrombotic or non-thrombotic lesions. The primary (1-year primary patency rate) and secondary (1-year overall survival rate) endpoints were evaluated.

Results: Thrombotic lesions were identified in 18.5% (64/346) of the patients. The 1-year primary patency (85.9% versus 95.4%, log-rank p ＜.001) and overall survival (90.6% versus 97.9%, log-rank p =.003) rates were significantly lower in the thrombotic group than in the non-thrombotic group. Thrombotic lesions had significant effects on the post-endovascular treatment outcomes, with adjusted hazard ratios of 3.91 (95% confidence interval, 1.64–9.34, p =.002) for primary patency and 4.93 (95% confidence interval, 1.59–15.3, p =.006) for all-cause mortality.

Conclusions: Thrombotic lesions were associated with 1-year restenosis and all-cause mortality after endovascular treatment for non-acute aortoiliac total occlusions. Endovascular treatment strategies should be carefully planned for patients with thrombotic lesions.

Identification of micro-channels within chronic total occlusions using contrast-enhanced ultrasound

BACKGROUND

Vascular micro-channels within chronic total occlusions (CTO) have been identified in histopathology and animal studies. They have been proposed as a potential path for achieving endovascular crossing via the lumen. There are currently no noninvasive means of imaging these structures. The aim of this study was to investigate whether contrast-enhanced ultrasound (CEUS) examination can identify micro-channels within CTO in humans.

METHODS

CTO within the femoropopliteal arteries were imaged with CEUS examination in 38 patients. Segments containing micro-channels were identified and their length measured. The proportion of occlusion length containing micro-channels was assessed for each case. Micro-channel appearances including linear or tortuous configuration, crossing of occlusion caps, and connections to vasa vasorum were recorded.

RESULTS

The median CTO length was 17.0 cm (interquartile range [IQR], 6.9-27.9 cm) and median age of CTO was 12 months (IQR, 6-16 months). Micro-channels were identified in 92.1% of cases (35/38). The median length within a lesion containing micro-channels was 6.4 cm (IQR, 2.4-14.3 cm) and median proportion of CTO containing micro-channels was 47.9% (IQR, 1.7%-28.5%). A linear micro-channel configuration was seen in 84.2% of cases and a tortuous configuration was seen in 57.9% of cases. Micro-channel connections through the cap were seen in 50% (19/38 cases) and connections to the vasa vasorum in 71.1% (27/38 cases). No association was found between the proportion of each lesion containing micro-channels and CTO age, lesion length or calcification severity. There were no adverse effects related to contrast use.

CONCLUSIONS

CEUS can be used to detect micro-channels in CTO in human femoropopliteal arteries. This imaging technique is safe and minimally invasive and may represent a practical method for selection of occlusion crossing method. Further work is required to determine whether identification of micro-channels can be used to improve treatment decision-making and provide a better understanding of the natural history of femoropopliteal CTO.

Definitions and Clinical Trial Design Principles for Coronary Artery Chronic Total Occlusion Therapies: CTO-ARC Consensus Recommendations

Over the past 2 decades, chronic total occlusion (CTO) percutaneous coronary intervention has developed into its own subspecialty of interventional cardiology. Dedicated terminology, techniques, devices, courses, and training programs have enabled progressive advancements. However, only a few randomized trials have been performed to evaluate the safety and efficacy of CTO percutaneous coronary intervention. Moreover, several published observational studies have shown conflicting data. Part of the paucity of clinical data stems from the fact that prior studies have been suboptimally designed and performed. The absence of standardized end points and the discrepancy in definitions also prevent consistency and uniform interpretability of reported results in CTO intervention. To standardize the field, we therefore assembled a broad consortium comprising academicians, practicing physicians, researchers, medical society representatives, and regulators (US Food and Drug Administration) to develop methods, end points, biomarkers, parameters, data, materials, processes, procedures, evaluations, tools, and techniques for CTO interventions. This article summarizes the effort and is organized into 3 sections: key elements and procedural definitions, end point definitions, and clinical trial design principles. The Chronic Total Occlusion Academic Research Consortium is a first step toward improved comparability and interpretability of study results, supplying an increasingly growing body of CTO percutaneous coronary intervention evidence.

Practical utilization of cardiac computed tomography for the success in complex coronary intervention

Percutaneous coronary intervention (PCI) for complex lesions is still technically demanding and is associated with less favorable procedural parameters such as lower success rate, longer procedural time, higher contrast volume and unexpected complications. Because the conventional angiographic analysis is limited by the inability to visualize the plaque information and the occluded segment, cardiac computed tomography has evolved as an adjunct to invasive angiography to better characterize coronary lesions to improve success rates of PCI. Adding to routine image reconstructions by coronary computed tomography angiography, the thin-slab maximum intensity projection method, which is a handy reconstruction technique on an ordinary workstation, could provide easy-to-understand images to reveal the anatomical characteristics and the lumen and plaque information simultaneously, and then assist to build an in-depth strategy for PCI. Especially in the treatment of chronic total occlusion lesion, these informations have big advantages in the visualization of the morphologies of entry and exit, the occluded segment and the distribution of calcium compared to invasive coronary angiography. Despite of the additional radiation exposure, contrast use and cost for cardiac computed tomography, the precise analysis of lesion characteristics would consequently improve the procedural success and prevent the complication in complex PCI.

Antegrade Dissection and Reentry: Tools and Techniques

The hybrid approach to chronic total occlusion percutaneous coronary intervention requires facility with antegrade and retrograde strategies to achieve high success rates in a time-efficient and safe manner. Antegrade dissection and reentry is an integral component of this approach but historically has been limited by low success rates and an inability to control the site of reentry. The advent of the BridgePoint device, and multiple iterations of technique in conjunction with its use, have markedly improved success rates and procedure efficiency.

Current status of hybrid intravascular ultrasound and optical coherence tomography catheter for coronary imaging and percutaneous coronary intervention

Both intravascular ultrasound (IVUS) and optical coherence tomography (OCT) play a crucial role in elucidating the pathophysiology of coronary artery disease (CAD) with the goal to improve patient outcomes of medical and/or interventional CAD management. However, no single intravascular imaging technique has been proven to provide complete and detailed evaluation of all CAD lesions due to some limitations. Although sequential use of multiple modalities may sometimes be performed, there may be issues related to risk, time, and cost. To overcome these problems, several hybrids involving dual-probe combined IVUS-OCT catheters have been developed. The aim of this review article is to demonstrate some limitations of stand-alone imaging devices for evaluation of CAD, summarize the advances in hybrid IVUS-OCT imaging devices, discuss the technical challenges, and present the potential value in the clinical setting, especially in patients receiving medical or interventional CAD management.

Retrograde-angioscopy guided wiring technique in chronic total occlusion lead to successful revascularization

Endovascular therapy (EVT) was performed in two cases with chronic total occlusion (CTO) of superficial femoral artery. In these cases, angioscopy was deployed in the backyard of the CTO lesion from popliteal artery retrogradely, then the guidewire was advanced from antegrade. When the wire crossed the distal of the CTO lesion, the wire penetration was clearly visualized by the retrograde-angioscopy. Therefore, wire crossing of CTO into the distal true lumen was certainly confirmed, and EVT was successful. <Learning objective: Angioscopy-guided endovascular therapy for chronic total occlusion was useful not only to evaluate thrombus and plaque in situ visually, but also to successfully perform guidewire crossing.>.

Scoring System for Identification of "Survival Advantage" after Successful Percutaneous Coronary Intervention in Patients with Chronic Total Occlusion

Background: Percutaneous coronary intervention (PCI) is widely used in patients with chronic total occlusion (CTO), but its benefit in improving long-term outcomes is controversial. We aimed to develop a prediction score for grading “survival advantage” conferred by successful results of CTO-PCI and a scoring system for prediction of the influence of CTO-PCI results on major adverse cardiac and cerebrovascular events (MACCEs). Methods: Follow-up data of 2625 patients who underwent CTO-PCI at 65 Japanese centers were analyzed. An integer scoring system was developed by including statistical effect modifiers on the association between successful CTO-PCI and one-year mortality. Results: Follow-up at 12 months was completed in 2034 patients. During follow-up, 76 deaths (3.7%) occurred. Patients with successful CTO-PCI had a better one-year survival than patients with failed CTO-PCI (log rank P = 0.016). Effect modifiers for the association between successful procedure and one-year mortality included diabetes (P interaction = 0.043), multivessel disease (P interaction = 0.175), Canadian Cardiovascular Society class ≥2 (P interaction = 0.088), and prior myocardial infarction (MI) (P interaction = 0.117). Each component was assigned a single point and summed to develop the scoring system. The patients were then categorized to specify the prediction of survival advantage by successful PCI: ≤2 (normal) and ≥3 (distinct). The differences in one-year mortality between patients with successful and failed treatment were −0.7% and 11.3% for normal and distinct score categories, respectively. In the scoring system for MACCE, score components were prior MI (P interaction = 0.19), left anterior descending artery (LAD)-CTO (P interaction = 0.079), and reattempt of CTO-PCI (P interaction = 0.18). The differences in one-year MACCEs between successful and failed patients for each score category (0, 1, and ≥2) were −1.7%, 7.5%, and 15.1%, respectively. Conclusions: The novel scoring system assessing the advantage of successful PCI can be easily applied in patients with CTO. It is a valid instrument for clinical decision-making while assessing the survival advantage of CTO-PCI and the influence of procedural results on MACCEs.

Factors associated with antegrade true-sub-true phenomenon in percutaneous coronary intervention for chronic total occlusion

Background

Recently, the importance of chronic total occlusion (CTO)-percutaneous coronary intervention (PCI) has been emphasized with greater success rates. In the antegrade wire based approach, it is generally considered that the guidewire would not advance from the subintimal space to the intimal space without dissection re-entry device. However, it is sometimes observed by intravascular ultrasound (IVUS) that the guidewire within the subintimal space advanced into the distal true lumen. The purpose of this study was to investigate specific conditions or characteristics which were associated with “antegrade true-sub-true” phenomenon in CTO-PCI.

Methods

We retrospectively reviewed consecutive 320 CTO lesions that underwent CTO-PCI in our institution. Among them, 16 lesions in which the IVUS confirmed the “antegrade true-sub-true” phenomenon were categorized as the true-sub-true group, whereas 27 lesions that resulted in unsuccessful CTO-PCI were categorized as the unsuccessful group. We compared the clinical, lesion, and procedural characteristics between the true-sub-true group and the unsuccessful group.

Results

The prevalence of bifurcation with abrupt type in CTO exit-sites was significantly higher in the true-sub-true group in comparison to the unsuccessful group (75.0% vs. 25.9%, p = 0.002). The multivariate logistic regression analysis revealed that bifurcation with abrupt type in CTO exit-site (OR 8.017; 95%CI: 1.484–43.304; p = 0.016) was independent predictor of the antegrade true-sub-true phenomenon.

Conclusions

In CTO-PCI, the antegrade true-sub-true phenomenon is rare, but can be a last chance for successful PCI. Bifurcation with abrupt type in CTO exit-site was significantly associated with the antegrade true-sub-true phenomenon.

Native Microchannel Recanalization with Orbital Atherectomy as a Viable Alternative to Failed Standard Recanalization of TASC II D Aortoiliac Occlusive Disease

BACKGROUND

Endovascular treatment of Trans-Atlantic Inter-Society Consensus (TASC) II D aortoiliac lesions is now an accepted form of revascularization. We sought to demonstrate that native microchannel recanalization and orbital atherectomy is a successful recanalization method of TASC II D aortoiliac lesions refractory to standard recanalization techniques.

METHODS

Four consecutive patients from 2016 to 2018 with symptomatic TASC II D aortoiliac occlusive disease prohibitive for open bypass and failed traditional prodding guidewire or device recanalization technique were identified and underwent advanced native microchannel selection and subsequent orbital atherectomy (Cardiovascular Systems, Inc, St Paul, MN). Native microchannels of the calcified lesions were probed and traversed with a 0.014″ wire. The atherectomy crown was tracked over the wire, and orbital atherectomy was initiated with a 1.25 mm crown starting at the lowest revolution and continued until the microchannel is sufficiently large to track a 1.2 mm-balloon for angioplasty. Serial microchannel angioplasty with exchange for stiffer and/or larger profile wires and balloons was achieved until a covered stent could be safely deployed across the target lesion. The kissing stent technique was then used to recreate the aortic bifurcation. A ViperSlide lubricant solution was used in all cases per indication for use. Patients were all heparinized to maintain an activated clotting time of 250. Lesion characteristics, survival, limb salvage, patency, and change in clinical symptoms were also analyzed.

RESULTS

All 4 patients underwent successful native microchannel recanalization and orbital atherectomy of the common iliac artery (CIA). There were no intraoperative ruptures, embolizations, or dissections. All 4 patients presented with unilateral CIA occlusion with contralateral CIA stenosis. The average occlusion lesion length of the CIA was 6.0 cm. The average contralateral stenosis length was 2.3 cm. The kissing stent technique was used in all patients for reconstruction of the aortic bifurcation. At 30 days, all patients had improvement in pain and primary patency of 100%. Long-term follow-up at 21.6 months noted continued improvement in symptoms and primary patency of 75%. The fourth patient died at 4 months from lung cancer with occluded iliac stents by imaging at that time.

CONCLUSIONS

Native microchannel recanalization with subsequent orbital atherectomy is an option in high-risk patients with TASC II D aortoiliac disease who have failed traditional recanalization techniques. Further work in proper patient selection and safe utilization of atherectomy devices in the CIA is needed.

A randomized multicentre trial to compare revascularization with optimal medical therapy for the treatment of chronic total coronary occlusions

Aims

The clinical value of percutaneous coronary intervention (PCI) for chronic coronary total occlusions (CTOs) is not established by randomized trials. This study should compare the benefit of PCI vs. optimal medical therapy (OMT) on the health status in patients with at least one CTO.

Method and results

Three hundred and ninety-six patients were enrolled in a prospective randomized, multicentre, open-label, and controlled clinical trial to compare the treatment by PCI with OMT with a 2:1 randomization ratio. The primary endpoint was the change in health status assessed by the Seattle angina questionnaire (SAQ) between baseline and 12 months follow-up. Fifty-two percent of patients have multi-vessel disease in whom all significant non-occlusive lesions were treated before randomization. An intention-to-treat analysis was performed including 13.4% failed procedures in the PCI group and 7.3% cross-overs in the OMT group. At 12 months, a greater improvement of SAQ subscales was observed with PCI as compared with OMT for angina frequency [5.23, 95% confidence interval (CI) 1.75; 8.71; P = 0.003], and quality of life (6.62, 95% CI 1.78-11.46; P = 0.007), reaching the prespecified significance level of 0.01 for the primary endpoint. Physical limitation (P = 0.02) was also improved in the PCI group. Complete freedom from angina was more frequent with PCI 71.6% than OMT 57.8% (P = 0.008). There was no periprocedural death or myocardial infarction. At 12 months, major adverse cardiac events were comparable between the two groups.

Conclusion

Percutaneous coronary intervention leads to a significant improvement of the health status in patients with stable angina and a CTO as compared with OMT alone.

Trial registration

NCT01760083.

Assessment of reattempted percutaneous coronary intervention strategy for chronic total occlusion after prior failed procedures: Analysis of the Japanese CTO-PCI Expert Registry

OBJECTIVES

We aimed to investigate strategies for reattempted percutaneous coronary interventions (PCIs) for chronic total occlusions (CTOs) by highly skilled operators after a failed attempt.

BACKGROUND

Development of complex techniques and algorithms has been standardized for CTO-PCI. However, there is no appropriate strategy for CTO-PCI after a failed procedure.

METHOD

From 2014 to 2016, the Japanese CTO-PCI Expert Registry included 4,053 consecutive CTO-PCIs (mean age: 66.8 ± 10.9 years; male: 85.6%; Japanese CTO [J-CTO] score: 1.92 ± 1.15). Initial outcomes and strategies for reattempted CTO-PCIs were evaluated and compared with first-attempt CTO-PCIs.

RESULTS

Reattempt CTO-PCIs were performed in 820 (20.2%) lesions. The mean J-CTO score of reattempt CTO-PCIs was higher than that of first-attempt CTO-PCIs (2.86 ± 1.03 vs. 1.68 ± 1.05, p < .001). The technical success rate of reattempt CTO-PCIs was lower than that of first-attempt CTO-PCIs (86.7% vs. 90.8%, p < .001). Regarding successful CTO-PCIs, the strategies comprised antegrade alone (reattempt: 36.1%, first attempt: 63.8%), bidirectional approach (reattempt: 54.4%, first attempt: 30.3%), and antegrade approach following a failed bidirectional approach (reattempt: 9.4%, first attempt: 5.4%). Parallel wire technique, intravascular ultrasound guide crossing, and bidirectional approach technique were frequently performed in reattempt CTO-PCIs. Reattempt CTO-PCIs showed higher rates of myocardial infarction (2.1% vs. 0.9%, p < .001) and coronary perforation (6.9% vs. 4.2%, p = .002) than first-attempt CTO-PCIs.

CONCLUSIONS

The technical success rate of reattempt CTO-PCIs is lower than that of first-attempt CTO-PCIs. However, using more complex strategies, the success rate of reattempt CTO-PCI can be improved by highly skilled operators.

Chronic Total Occlusion Wiring: A State-of-the-Art Guide From The Asia Pacific Chronic Total Occlusion Club

OBJECTIVE

Despite the advances in wire technology and development of algorithm-driven methodology for chronic total occlusion (CTO) intervention, there is a void in the literature about the technical aspects of CTO wiring. The Asia Pacific CTO Club, a group of 10 experienced operators in the Asia Pacific region, has tried to fill this void with this state-of-the-art review on CTO wiring.

METHODS

This review explains, for proximal cap puncture: choices of wires, shaping of the wire, use of dual lumen catheter, and method of step-down of wire penetration force for successful wiring. In wiring the CTO body, the techniques of loose tissue tracking, intentional intimal plaque tracking, and intentional subintimal wiring are described in detail. For distal lumen wiring, a blunt distal cap, presence of a distal cap side branch, calcium, and sharp tapered distal stump predict cap toughness, and wire penetration force should be stepped-up in these cases. The importance of choosing between redirection, parallel wiring, and Stingray (Boston Scientific, Marlborough, MA, USA) for angiographic guidance is discussed along with which will be more successful. On the retrograde side, the problems encountered with distal cap puncture and methods to overcome these problems are explained. The method of wiring the CTO body through a retrograde approach depending on the morphology of the CTO is described. Different reverse controlled antegrade and retrograde tracking (CART) wiring methods - including end balloon wiring, side balloon entry, and conventional reverse CART - are explained in detail.

CONCLUSION

This is a systematic CTO wiring review, which is believed to be beneficial for CTO operators worldwide.

Comparison of the transradial and transfemoral approach in treatment of chronic total occlusions with similar lesion characteristics

Objective:

There is limited data on the efficacy and the safety of the transradial approach (TRA) for percutaneous coronary intervention (PCI) of chronic total occlusion (CTO), particularly in comparison with the transfemoral approach (TFA) in lesions with similar complexity.

Methods:

We included 358 patients, who underwent elective CTO PCI between January 2012 and August 2017 and compared the radial (179 patients) and femoral (179 patients) approaches. The J-CTO score was similar in both groups (TRA, 2.5±1.3 vs. TFA, 2.8±1.4, n.s.). The endpoints analyzed included (i) the composite of all-cause death and nonfatal myocardial infarction (MI) and (ii) the composite safety endpoint of major adverse cardiovascular and cerebrovascular events (MACCEs), including death, MI, coronary perforation, contrast-induced nephropathy (CIN), bleeding at the vascular access site requiring transfusion, cardiac tamponade requiring pericardiocentesis, and periprocedural stroke.

Results:

Patients’ demographics, lesion location, lesion characteristics, and the proportion of antegrade vs. retrograde approach were similar in both groups. The procedural success rate of 96.4% in the radial group and 92.9% in the femoral group was comparable. The total fluoroscopy time (TRA, 42.4±15.7 min vs. TFA, 40.5±15.3 min, n.s.) and contrast medium use (TRA, 532.2±21.7 mL vs. TFA, 528.2±24.6 mL, n.s.) was similar in both groups. There was no in-hospital death or periprocedural MI in both groups. There were three coronary perforations in the TFA group, among them one with tamponade, and one coronary perforation the TRA group. Vascular access site complications (TRA, 0.01% vs. TFA, 0.02%) and CIN (TRA, 0.006% vs. TFA, 0.006%) were rare. One stroke as a result of the procedure was observed in the TFA group. No death was registered.

Conclusion:

The radial approach in CTO PCI was as fast and successful as the femoral approach, even in a complex lesion subset.

Optimal use of fielder XT guidewire enhances the success rate of chronic total occlusion percutaneous coronary intervention

BACKGROUND

Chronic total occlusion (CTO) is found in 18-31% of patients who undergo coronary angiography. Successful recanalization of CTOs is associated with reduced recurrent angina pectoris rates and increased long-term survival. Although the success rate of CTO percutaneous coronary intervention (CTO-PCI) has improved, CTO-PCI remains technically challenging. The Fielder XT guidewire was designed for CTO lesions. To validate whether the use of the guidewire increases the success rate, we compared the results of CTO-PCI with or without the guidewire. We hypothesized that the use of Fielder XT guidewire can increase the success rate of CTO-PCI.

AIM

To investigate whether the use of Fielder XT guidewire increases the final procedural success of CTO-PCI via the anterograde approach.

METHODS

Between January 2013 and December 2015, a retrospective study was conducted on 1230 consecutive patients with CTO who received PCI via the anterograde approach at the General Hospital of Northern Theater Command. The patients were divided into an XT Group (n = 686) and a no-XT Group (n = 544) depending on whether Fielder XT guidewire was used. Both groups were compared for clinical parameters, lesion-related characteristics, procedural outcomes and in-hospital complications. The data were statistically analyzed using Pearson's χ 2 test for categorical variables, and Students' t test was used to compare the quantitative data. Significant independent factors and a risk ratio with 95% confidence interval (CI) were assessed by multivariate logistic regression analysis.

RESULTS

In total, 1230 patients were recruited; 75.4% of the patients were male, and 55.8% of the patients were in the XT group. The overall success rate was 83.9%, with 87.8% in the XT group. Based on multivariate logistic regression analysis, factors positively associated with procedural success were the use of Fielder XT guidewire (P = 0.005, 95%CI: 1.172-2.380) and systolic blood pressure (P = 0.011, 95%CI: 1.003-1.022), while factors negatively associated with procedural success were blunt stump (P = 0.013, 95%CI: 1.341-11.862), male sex (P = 0.016, 95%CI: 0.363-0.902), New York Heart Association (NYHA) class (P = 0.035, 95%CI: 0.553-0.979), contrast amount (P = 0.018, 95%CI: 0.983-0.998) and occlusion time (P = 0.009, 95%CI: 0.994-0.999). No significant differences were found between the XT group and the no-XT group with respect to clinical parameters, lesion-related characteristics, coronary artery rupture [3 (0.4%) vs 8 (1.5%), P = 0.056], in-hospital death [2 (0.3%) vs 6 (1.1%), P = 0.079] or in-hospital target lesion revascularization [3 (0.4%) vs 7 (1.3%), P < 0.099]. However, there were significant differences between the groups with respect to success rate [602 (87.8%) vs 430 (79.0%), P < 0.001], procedure time [(74 ± 23) vs (83 ± 21), P < 0.001], stent length [(32.0 ± 15.8) vs (37.3 ± 17.6), P < 0.001], contrast amount [(148 ± 46) vs (166 ± 43), P < 0.001], post-PCI myocardial infarction [43 (6.3%) vs 59 (10.8%), P = 0.004], major adverse cardiovascular event [44 (6.4%) vs 57 (10.7%), P = 0.007], side branch loss [31 (4.5%) vs 44 (8.1%), P = 0.009], contrast-induced nephropathy [29 (4.2%) vs 40 (7.4%), P = 0.018] and no reflow [8 (1.2%) vs 14 (2.9%), P = 0.034].

CONCLUSION

The use of Fielder XT guidewire shortens the Procedure and increases the success rate of CTO-PCI, and is also associated with reduced complication rates.

The Wire Rendezvous and Chasing Wire Technique in the Bidirectional Approach for the Percutaneous Coronary Intervention for Chronic Total Occlusion with a Single Guiding Catheter

A bidirectional approach for percutaneous coronary intervention for chronic total occlusion (CTO-PCI) using ipsilateral collaterals with a single guiding catheter limits procedural choices. The CTO of the left circumflex artery with ipsilateral collateral artery was treated by the bidirectional approach using a single guiding catheter. While the retrograde wire directly crossed the CTO lesion, the microcatheter could not pass the CTO lesion despite the conventional strategies. Therefore, we performed the wire rendezvous and chasing wire techniques. The wire rendezvous technique enables deeper retrograde guidewire progression, and the antegrade microcatheter can reach the CTO entry. The chasing wire technique enables the antegrade guidewire to pass the route made by the retrograde guidewire. These techniques might offer a possible solution for bidirectional CTO-PCI using a single guiding catheter. However, this technique should be considered as a last resort because of the risk of rapid reocclusion.

Intravascular Ultrasound and Angioscopy Assessment of Coronary Plaque Components in Chronic Totally Occluded Lesions

BACKGROUND

The in vivo lesion morphologies and plaque components of coronary chronic total occlusion (CTO) lesions remain unclear.

METHODS AND RESULTS

We investigated 57 consecutive CTO lesions in 57 patients with stable angina pectoris undergoing elective percutaneous coronary intervention with intravascular ultrasound (IVUS) and coronary angioscopy (CAS) examination. All CTO lesions were classified according to the proximal angiographic lumen pattern; tapered-type (T-CTO) and abrupt-type (A-CTO). The differences in the intracoronary images of these lesion types were evaluated according to the location within the CTO segment. A total of 35 lesions (61.4%) were T-CTO. T-CTO lesions had higher frequencies of red thrombi (proximal 71.4%; middle 74.3%; distal 31.4%; P<0.001) and bright-yellow plaques (yellow-grade 2-3) (48.6%; 74.3%; 2.9%; P<0.001) at the proximal or middle than at the distal subsegment; A-CTO lesions showed no significant differences among the 3 sub-segments. At the middle subsegment, T-CTO lesions showed higher frequencies of positive remodeling (51.4% vs. 18.2%, P=0.01) and bright-yellow plaques (74.3% vs. 13.6%, P<0.001) compared with A-CTO lesions. Multivariate analysis identified bright-yellow plaque as an independent predictor (odds ratio, 7.25; 95% confidence interval, 1.25-42.04; P=0.03) of the occurrence of periprocedural myocardial necrosis.

CONCLUSIONS

The combination of IVUS and CAS analysis may be useful for identifying lesion morphology and plaque components, which may help clarify the pathogenetic mechanism of CTO lesions.

Coronary chronic total occlusion intervention: A pathophysiological perspective

Percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) is the last frontier in coronary intervention. PCI of CTO carries multiple advantages, such as significant improvement in symptoms, improvement in abnormal wall motion and left ventricular function and, possibly, increased long-term survival. As of today the procedural success is markedly improved because of technical innovations and is limited to highly experienced operators. To enhance the overall success rate from a worldwide perspective, a thorough understanding of its pathophysiology is critical to further development of newer techniques and technologies. In this review, the author outlines in-depth the evidence that underpins our understanding of CTO pathophysiology and its insight into CTO intervention that incorporates various steps and techniques to cross the lesion.

Impact of Chronic Kidney Disease on Outcomes After Percutaneous Coronary Intervention for Chronic Total Occlusions (from the Japanese Multicenter Registry)

The impact of chronic kidney disease (CKD) and potential pharmacologic intervention on clinical outcomes after percutaneous coronary intervention (PCI) for chronic total occlusions (CTOs) remains unknown. A total of 1,463 patients underwent successful CTO-PCI between August 2004 and December 2014. Major adverse cardiovascular events (MACE) defined as the composite of all-cause death, myocardial infarction and target lesion revascularization, cardiac death, and stent thrombosis were compared between patients with and without CKD (555 and 908 patients, respectively). The results demonstrated higher risks of MACE (log-rank p = 0.015), all-cause death (log-rank p <0.001), and cardiac death (log-rank p <0.001) in the CKD group compared with the non-CKD group. Multivariable analyses demonstrated that CKD was an independent predictor for MACE (hazard ratio 1.23, 95% confidence interval 1.02 to 1.47, p = 0.03). With regard to pharmacotherapy, statin use was associated with significantly lower rates of MACE in the CKD group (log-rank p = 0.003). In conclusion, the presence of CKD would be an important predictor of long-term clinical outcomes in patients who underwent CTO-PCI, and use of statin may influence in reducing the adverse clinical outcomes.

Epicardial collateral channel for retrograded recanalization of chronic total occlusion percutaneous coronary intervention: Predictors of failure and procedural outcome

OBJECTIVES

This study set out to identify significant lesion features of chronic total occlusion (CTO) that predict successful retrograde recanalization via epicardial collateral channels (CCs).

BACKGROUND

Epicardial CCs remain essential in retrograde percutaneous coronary intervention (PCI) of CTO. However, the unpredictability of success and occurrence of complications limit the application of epicardial CCs for retrograde PCI technique for CTO.

METHODS

103 retro-recanalization cases were analyzed using epicardial CCs with successful recanalization as an end point. Clinical and angiography data were collected.

RESULTS

The total success rate was 76.3%. Independent predictors associated with technical success included CCs tortuosity, side branch at CCs tortuosity, inadequate CCs Size and inadequate CCs exit location. Assigning a score of one for each variable, four levels of difficulty were obtained and formed the EPI-CTO score (Epicardial CTO). This score had significant predictive value for the likelihood of successful recanalization (AUC: 0.94, 95%CI: 0.89-0.98). Coronary and CCs perforation occurred in 6 and 10 cases respectively. Four cases including two coronary and two CCs perforations had tamponade that needed pericardiocentesis.

CONCLUSIONS

Using epicardial CCs for retrograde approach of CTO PCI is effective. Complication rate was acceptable. We found four independent predictors relative to procedure success.

Morphological assessment of chronic total occlusions by combined coronary computed tomographic angiography and intravascular ultrasound imaging

Aims

The relationship between CTO morphology and vessel remodelling is unclear. We described chronic total occlusion (CTO) morphology using coronary computed tomographic angiography (CCTA) combined with intravascular ultrasound (IVUS).

Methods and results

Pre-intervention CCTA and IVUS of 130 CTO lesions (128 patients) were evaluated. Based on CCTA, positive CTO lesion remodelling [PR, maximum CTO segment vessel diameter > proximal reference vessel diameter (RVD)] was seen in 44 (33.8%) lesions. In the other 86 lesions without PR, 74 (56.9%) had a minimum CTO segment vessel diameter >50% of the proximal RVD and were classified as non-PR; 12 (9.2%) lesions had a minimum CTO segment vessel diameter ≤50% of the proximal RVD and were classified as collapse. Comparing the three groups, CTO with PR had the greatest maximum atheroma cross-sectional area (CSA) while the collapse group had the least atheroma CSA (16.0 mm2 [12.0, 19.4] vs. 9.1 mm2 [6.0, 15.9], P < 0.001). The maximum arc of attenuated plaque was greatest in the PR group (51° [0, 167]); and the maximum arc of calcium was greatest in the non-PR group (91° [51, 174]). In the collapse group distal to the occluded segment, there was a normal-appearing vessel by IVUS that corresponded to the collapsed segment by CCTA; its minimum plaque burden was 33.2% [19.9, 38.1] with a smooth concave-shaped lumen surface, implying that the CCTA collapse segment was not occluded.

Conclusion

Not all CTOs are the same with regard to lesion remodelling and underlying morphology. The combination of IVUS and CCTA can help to categorize CTO morphology.

Novel proctorship effectively teaches interventionists coronary artery chronic total occlusion lesions

BACKGROUND

Interventionists' experience and skills are essential factors for successful chronic total occlusion-percutaneous coronary intervention (CTO-PCI). However, the construction of theoretical strategy independent from interventionists' procedure may also improve it. We sought to assess the feasibility of CTO-PCI using an educational system supported by a single expert proctor.

METHODS

A total of 160 patients underwent CTO-PCI between 2009 and 2016 at 92 Japanese centers in the Hands-on proctorship project. The CTO-PCI strategy was discussed with all participants and their specialists, before and during the procedure. We divided patients into 2 groups based on the CTO-PCI experience of their interventionist: (1) the less experienced group (CTO-PCI ≤50 cases, n=65) and (2) the more experienced group (CTO-PCI >50 cases, n=95). Baseline characteristics, procedural complications, and clinical outcomes were compared between groups.

RESULTS

No significant differences in patient age, sex, prevalence for coronary risk factors, and lesion complexity was observed between groups. The retrograde approach was used equivalently between groups (55.4% vs. 60.0%, p=0.56), and procedural success rates were similar (96.9% vs. 90.5%, p=0.12). The rate of proctor's bailout for recanalization were not frequent between groups (4.6% vs. 5.3%, p=0.85). No procedure-related mortality was noted in either group. In addition, no significant differences in procedural cardiac complications, including coronary dissection, perforation, or tamponade, were observed between groups (10.8% vs. 14.7%, p=0.47).

CONCLUSIONS

The expert-supported CTO-PCI maintained high success rates regardless of interventionists' experience. This highlights the importance of theoretical strategy for the management patients undergoing CTO-PCI.

Impact of Hemodialysis on Procedural Outcomes of Percutaneous Coronary Intervention for Chronic Total Occlusion: Insights From the Japanese Multicenter Registry

BACKGROUND

Among patients treated with percutaneous coronary intervention for chronic total occlusion (CTO-PCI), patients on long-term hemodialysis are at significantly high risk for cardiovascular mortality and morbidity. However, clinical or angiographic predictors that might aid in better patient selection remain unclear. We aimed to assess the acute impact of hemodialysis in patients who underwent CTO-PCI.

METHODS AND RESULTS

The Retrograde Summit registry is a multicenter, prospective registry of patients undergoing CTO-PCI at 65 Japanese centers. Patient characteristics and procedural outcomes of 4749 patients were analyzed, according to the presence (n=313) or absence (n=4436) of baseline hemodialysis. A prediction model for technical failure among hemodialysis patients was also developed. The technical success rate of CTO-PCI was significantly lower in hemodialysis than in nonhemodialysis patients (78.0% versus 89.1%, P<0.001). The rates of in-hospital major adverse cardiac and cerebrovascular events were similar between the 2 groups (1.6% versus 0.9%, P=0.24). Irrespective of clinical/angiographic characteristics or previously developed scoring systems, hemodialysis independently predicted technical failure for CTO-PCI. Among hemodialysis patients, predictors of technical failure were blunt stump (odds ratio 2.45, 95% confidence interval, 1.15-5.21, P=0.021), severe lesion calcification (odds ratio 2.50, 95% confidence interval, 1.19-5.24, P=0.015), and absence of diabetes mellitus (odds ratio 3.15, 95% confidence interval, 1.49-6.64, P=0.003). In hemodialysis patients without these predictors, the technical success rate was 96.2%.

CONCLUSIONS

Hemodialysis is significantly associated with technical failure. Contemporary CTO-PCI seems feasible and safe in selected hemodialysis patients.