Intravascular Ultrasound Analysis of Intraplaque Versus Subintimal Tracking in Percutaneous Intervention for Coronary Chronic Total Occlusions and Association With Procedural Outcomes

Drug-coated balloon versus drug-eluting stent for femoropopliteal total occlusions: intraluminal versus subintimal approaches

Because there is a lack of comparative studies assessing drug-coated balloon (DCB) and drug-eluting stent (DES) outcomes with respect to intraluminal (IL) and subintimal (SI) approaches in femoropopliteal (FP) total occlusive lesions, we compared the outcomes between DCB (including bailout stenting) and DES treatments for this lesion. A total of 487 limbs (434 patients) were divided into the IL (n = 344, DCB: n = 268, DES: n = 76) and SI (n = 143, DCB: n = 83, DES: n = 60) approach groups. The primary outcome was a major adverse limb event (MALE), defined as above-ankle amputation or repeat revascularization of the index limb. Secondary outcomes included clinically driven target lesion revascularization (TLR), loss of clinical patency, and all-cause death. After adjustment, in each IL and SI approach, the 2-year rates of MALE (p = 0.180 and p = 0.236, respectively), TLR, loss of clinical patency, and all-cause death were similar between the DCB and DES groups. In the DCB and DES groups, both primary and secondary outcomes were similar between the IL and SI approaches. DCB and DES strategies for patients presenting with FP total occlusive lesions demonstrated similar outcomes regardless of the IL or SI approach.Clinical Trial Registration: NCT02748226.

Dissection and Re-entry Techniques for Chronic Total Occlusion Percutaneous Coronary Intervention

Despite early stagnation in success rates for percutaneous coronary intervention for chronic total occlusion with the traditional antegrade wiring approach, the introduction of dissection/re-entry techniques and the retrograde approach opened new avenues for operators to tackle more complex occlusions. Dissection/re-entry techniques (both antegrade and retrograde) are commonly used in angiographic scenarios characterised by long, tortuous and calcified occlusions, as well as in those with proximal cap ambiguity. Familiarity and comfort using the extraplaque space (with either an antegrade or retrograde approach) have become fundamental to achieving safe and effective recanalisation of complex chronic total occlusions. This review provides an overview of different contemporary antegrade and retrograde dissection re-entry techniques and their acute and longer-term outcomes.

Current evidence for prognostic benefit of intravascular imaging-guided percutaneous coronary intervention in chronic total occlusion intervention

Although percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) has been increasing in recent years, CTO PCI is still one of the most challenging procedures with relatively higher rates of procedural complications and adverse clinical events after PCI. Due to the innate limitations of invasive coronary angiography, intravascular imaging (IVI) has been used as an adjunctive tool to complement PCI, especially in complex coronary artery disease. Considering the complexity of CTO lesions, the role of IVI is particularly important in CTO intervention. IVI has been a useful adjunctive tool in every step of CTO PCI including assisted wire crossing, confirmation of wire location within CTO segment, and stent optimization. The meticulous use of IVI has been one of the greatest contributors to recent progress of CTO PCI. Nevertheless, studies evaluating the role of IVI during CTO PCI are limited. The current review provides a comprehensive overview of the mechanistic advantages of IVI in CTO PCI, summarizes previous studies and trials, and presents future perspective of IVI in CTO PCI.

Antegrade techniques for chronic total occlusion percutaneous coronary intervention

Antegrade techniques are the foundation of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Antegrade wiring with the intent to achieve an intraplaque guidewire tracking is not always feasible, and crossing into the extraplaque space with subsequent reentry (antegrade dissection and reentry), might be needed, particularly in more complex occlusions. The present article reviews in detail the antegrade approaches to CTO PCI, focusing on equipment, techniques, and overcoming challenges.

Successful true cavity pathfinding with balloon assisted CTO with bifurcation lesions: Two case reports

BACKGROUND

Coronary artery disease is a prevalent global cardiovascular ailment, with percutaneous coronary intervention (PCI) standing out as a crucial method for relieving symptoms and enhancing the quality of life in patients with coronary heart disease. However, the presence of concurrent chronic total occlusion (CTO) and bifurcation lesions within coronary arteries elevates the complexity and treatment risks, especially when the entry point of the CTO is ambiguous.

OBJECTIVE

This study aims to present an innovative approach for treating CTO complicated with bifurcation lesions, focusing on true cavity pathfinding assisted by a balloon.

METHODS

Two cases of CTO patients with concomitant bifurcation lesions are described. One case involves CTO of the left anterior descending artery) combined with anterior non-angle trigeminal lesions, while the other entails CTO of the posterior left artery combined with posterior angle trigeminal lesions. True lumen identification using a balloon and subsequent opening of the CTO blood vessel were performed in both cases.

RESULTS

In both cases, the true lumen was successfully located with the assistance of a balloon, leading to the successful opening of the CTO blood vessel. This approach not only simplified the procedure but also reduced procedural difficulty and associated risks of complications compared to traditional guide wire operations.

CONCLUSION

The application of true cavity pathfinding assisted by a balloon offers a novel and effective strategy for managing CTO complicated with bifurcation lesions. The method simplifies the procedure, decreases procedural difficulty, and lowers the risk of complications associated with guide wire operations. However, further studies and long-term follow-up data are warranted to validate the reliability and long-term efficacy of this innovative approach.

Antegrade wire escalation in chronic total occlusions: State of the art review

Coronary chronic total occlusion percutaneous coronary intervention treatment algorithms have helped to standardize crossing strategy sequence to improve efficacy and efficiency of CTO interventions based on angiographic criteria. Unfortunately, advanced crossing techniques such as a retrograde and subintimal guidewire tracking and reentry that have accelerated procedural success in more difficult lesions are associated with higher major adverse cardiac event rates as compared with traditional antegrade and intimal guidewire tracking. In this regard, antegrade wire escalation (AWE) remains the most common CTO crossing strategy. In this state of the art review, we outline the techniques employed to maximize the clinical utility of AWE crossing strategy for both novice operators as well as those experienced with the advanced crossing strategies. For the less experienced operator, these techniques may provide a framework to treat more patients safely and effectively without the need to refer to a more advanced operator. Whereas these same techniques may be employed by an advanced operator to improve the technical success in procedures requiring more advanced crossing strategies.

The role of intravascular imaging in chronic total occlusion percutaneous coronary intervention

Chronic total occlusions (CTOs) represent the most complex subset of coronary artery disease and therefore careful planning of CTO percutaneous coronary recanalization (PCI) strategy is of paramount importance aiming to achieve procedural success, and improve patient's safety and post CTO PCI outcomes. Intravascular imaging has an essential role in facilitating CTO PCΙ. First, intravascular ultrasound (IVUS), due to its higher penetration depth compared to optical coherence tomography (OCT), and the additional capacity of real-time imaging without need for contrast injection is considered the preferred imaging modality for CTO PCI. Secondly, IVUS can be used to resolve proximal cap ambiguity, facilitate wire re-entry when dissection and re-entry strategies are applied and most importantly to guide stent deployment and optimization post implantation. The role of OCT during CTO PCI is currently limited to stent sizing and optimization, however, due to its high spatial resolution, OCT is ideal for detecting stent edge dissections and strut malapposition. In this review, we describe the use of intravascular imaging for lesion crossing, plaque characterization and wire tracking, extra- or intra-plaque, and stent sizing and optimization during CTO PCI and summarize the findings of the major studies in this field.

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.

Utility of Guiding Catheter Extensions for Recanalization of Chronic Total Occlusions: A EuroCTO Club Expert Panel Report

Guiding catheter extensions (GCEs) have become indispensable tools in the modern approach to percutaneous coronary intervention (PCI). The support offered during complex PCI of uncrossable, or tortuous lesions is particularly valuable in the setting of chronic total occlusions (CTO), both for conventional anterograde wire escalation and for anterograde or retrograde dissection and re-entry techniques. This EuroCTO consensus document describes the use of GCE during CTO recanalization and provides a practical guide to anatomies and techniques in which these devices are applicable. We describe the peculiar features of the most-used device and the practical technique for GCE delivery in standard PCI; further specific indications for antegrade and retrograde CTO PCI are discussed in a specific section. In the antegrade approach, the GCEs may be useful to increase support or facilitate antegrade dissection and re-entry techniques, while in the retrograde approach for reverse controlled antegrade and retrograde tracking, to increase retrograde support for gear delivery, for treatment of CTO in bifurcation and ipsilateral externalization with a single guide catheter. The last section of the paper describes GCE-related complications, challenges, limitations, and future perspectives.

Role of the retrograde Carlino technique for chronic total occlusion percutaneous coronary intervention

BACKGROUND

There is scarce data on the outcomes of the Carlino technique for chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We aimed to investigate the indications and outcomes of the Carlino technique as performed in the context of the retrograde approach.

METHODS

We pooled CTO PCI cases where a retrograde Carlino technique was performed from high-volume operators at four centers. The Carlino technique was characterized according to its indication (achieving plaque/cap modification, clarifying microcatheter location within the vessel, resolving distal cap ambiguity) and was considered successful when it led to the desired outcome.

RESULTS

A total of 43 patients were included. Occlusion complexity was very high (mean J-CTO score 3.3 ± 0.8). The two most common indications were understanding the anatomy of the occlusion and clarifying gear location (37.2%) and impenetrable distal cap (34.9%). The Carlino technique was successful in 88.4% of cases. Overall technical and procedural success was 86.0%. The most common successful crossing technique was reverse controlled antegrade and retrograde subintimal tracking (70.3%). No complications were attributed to the Carlino technique.

CONCLUSIONS

We observed a high success rate of the retrograde Carlino technique, as well as overall technical and procedural success rates. No Carlino technique-related complications were observed. Additional data from larger registries are warranted to further confirm the safety and efficacy of this technique.

Subintimal shift as mechanism for side-branch occlusion in percutaneous treatment of chronic total occlusions with bifurcation lesions

BACKGROUND

The aim of this study was to describe the mechanism of subintimal shift (SIS), standardise diagnostic criteria and sensitise the interventional community to this phenomenon. The treatment of chronic total occlusions (CTO) by means of percutaneous coronary intervention (PCI) is complicated by bifurcation lesions involved in the CTO segment or adjacent to it. Extraplaque expansion of intracoronary devices during CTO PCI may extend the dissection plane over the bifurcation with the consequential side or main branch compression by an intimo-medial flap. This phenomenon is hereby described for the first time and named subintimal shift.

METHODS

Experienced CTO operators from 3 international high volume centers for CTO PCI retrospectively searched their personal records for paradigmatic cases of SIS, summarising key features and proposing diagnostic criteria.

RESULTS

The series comprised 7 demonstrative cases, illustrating SIS by intravascular imaging (2 cases) or indirect angiographic signs during CTO PCI (5 cases). Five cases were triggered by stent expansion, 1 by balloon inflation and 1 case was aborted after angiographic warning signs. In 4 cases, SIS resulted in total occlusion of a branch, refractory to ballooning whenever attempted. Four cases required bailout intervention and in 2 cases the branch was left occluded, resulting in a rise of cardiac markers.

CONCLUSIONS

Subintimal shift is a noteworthy complication in CTO bifurcations, potentially resulting in occlusion of the relevant side or even the main branch. Intracoronary imaging prior to stenting is recommended to understand the tissue planes. Some counterintuitive peculiarities of this phenomenon, like its refractoriness to ballooning, must be known by CTO operators for its efficient resolution.

Why and How Should We Treat Chronic Total Occlusion? Evolution of State-of-the-Art Methods and Future Directions

Chronic total occlusions are considered the most complex coronary lesion in interventional cardiology. The absence of visible lumen on angiography obscures the vessel course and makes vessel wiring unlikely with conventional techniques. Often a source of severe ischemia, chronic occlusions are also markers of advanced atherosclerosis that brings other complex features including lesion length, bifurcations, calcification, adverse vessel remodelling, distal disease, and anatomic distortion from previous bypass grafting. Often advanced atherosclerosis is associated with patient characteristics like left ventricular dysfunction, previous coronary bypass surgery, or multivessel disease that increase procedural demands and hazards. To accommodate these challenges new techniques and dedicated technologies have been developed. When applied to appropriate patients, these advances have improved procedural success, safety, and outcomes. Our aim is to provide the general cardiologist with an overview of these advances that can serve as a basis for counselling patients considered for revascularization.

Extraplaque versus intraplaque tracking in chronic total occlusion percutaneous coronary intervention

OBJECTIVE

To compare the clinical outcomes after extraplaque (EP) versus intraplaque (IP) tracking in chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

BACKGROUND

The impact of modern dissection and reentry (DR) techniques on the long-term outcomes of CTO PCI remains controversial.

METHODS

We performed a systematic review and meta-analysis of studies that compared EP versus IP tracking in CTO PCI. Odds ratios (ORs) with 95% confidence intervals (CIs) are calculated using the Der-Simonian and Laird random-effects method.

RESULTS

Our meta-analysis included seven observational studies with 2982 patients. Patients who underwent EP tracking had significantly more complex CTOs with higher J-CTO score, longer lesion length, and more severe calcification and had significantly longer stented segments. During a median follow-up of 12 months (range 9-12 months), EP tracking was associated with a higher risk of major adverse cardiovascular events (MACE) (OR 1.50, 95% CI (1.10-2.06), p = 0.01) and target vessel revascularization (TVR) (OR 1.69, 95% CI (1.15-2.48), p = 0.01) compared with IP tracking. There was no difference in the incidence of all-cause death (OR 1.37, 95% CI (0.67-2.78), p = 0.39), myocardial infarction (MI) (OR 1.48, 95% CI (0.82-2.69), p = 0.20), stent thrombosis (OR 2.09, 95% CI (0.69-6.33), p = 0.19), or cardiac death (OR 1.10, 95% CI (0.39-3.15), p = 0.85) between IP and EP tracking.

CONCLUSION

EP tracking is utilized in more complex CTOs and requires more stents. EP tracking is associated with a higher risk of MACE, driven by a higher risk of TVR at 1 year, but without an increased risk of death or MI compared with IP tracking. EP tracking is critically important for contemporary CTO PCI.

A novel use of small ballons to reduce the risk of subintimal hematoma formation during recanalization of chronic total occlusion: two case reports

Background

Subintimal hematoma remains a major challenge associated with unnecessary technical complexity, failure of the antegrade approach or imperfection of revascularization in percutaneous coronary intervention (PCI) for chronic total occlusion (CTO). Some techniques and devices release the hematoma after its formation. Here, we describe a novel use of small ballons to prevent the hematoma formation during antegrade approach in two cases.

Case presentation

We report two cases of CTO-PCI in which balloon occlusion was successfully applied to prevent haematoma formation. The first case, a 72-year-old female with diabetes, was hospitalized because of unstable angina. Angiography showed right coronary artery (RCA) CTO, which initiated from the proximal part to the trifurcation at the distal part of the RCA. Considering the high likelihood and serious consequences of subintimal haematoma, a small balloon is employed to prevent subintimal hematoma formation. A balloon and microcatheter or double-lumen microcatheter are placed in the proximal coronary CTO lesion; then the balloon was dilated beside the catheter, most of the antegrade blood flow was sealed which reduced the likelihood of haematoma formation. The procedure was successfully completed without subintimal hematoma formation. The second case a 62-year-old male with unstable angina, was hospitalized for PCI. Angiography showed left anterior descending coronary artery CTO. Similar to case 1, we also used a small balloon to prevent hematoma formation. Both patients underwent PCI, which employed a small balloon to prevent hematoma formation and both procedures were successful without complications.

Conclusion

In patients who underwent CTO-PCI, balloon occlusion offers an alternative for reducing the incidence of subintimal haematomas.

Chronic total occlusion revascularization: A complex piece to "complete" the puzzle

Treatment of coronary chronic total occlusion (CTO) with percutaneous coronary intervention (PCI) has rapidly increased during the past decades. Different strategies and approach were developed in the recent past years leading to an increase in CTO-PCI procedural success. The goal to achieve an extended revascularization with a high rate of completeness is now supported by strong scientific evidences and consequently, has led to an exponential increase in the number of CTO-PCI procedures, even if are still underutilized. It has been widely demonstrated that complete coronary revascularization, achieved by either coronary artery bypass graft or PCI, is associated with prognostic improvement, in terms of increased survival and reduction of major adverse cardiovascular events. The application of “contemporary” strategies aimed to obtain a state-of-the-art revascularization by PCI allows to achieve long-term clinical benefit, even in high-risk patients or complex coronary anatomy with CTO. The increasing success of CTO-PCI, allowing a complete or reasonable incomplete coronary revascularization, is enabling to overcome the last great challenge of interventional cardiology, adding a “complex” piece to “complete” the puzzle.

Contemporary Issues in Chronic Total Occlusion Percutaneous Coronary Intervention

Remarkable progress has been achieved in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in recent years, with refinement of the indications and technical aspects of the procedure, imaging, and complication management. Randomized controlled trials and rigorous prospective registries have provided high-quality data on the benefits and risks of CTO PCI. Global collaboration has led to an agreement on nomenclature, indications, endpoint definition, and principles of clinical trial design that have been distilled in global consensus documents such as the CTO Academic Research Consortium. Increased use of preprocedural coronary computed tomography angiography and intraprocedural intravascular imaging, as well as development of novel techniques and structured CTO crossing and complication management algorithms, allow a systematic, stepwise approach to this difficult lesion subset. This state-of-the-art review provides a comprehensive discussion about the most recent developments in the indications, preprocedural planning, technical aspects, complication management, and future directions of CTO PCI.

CTO in Contemporary PCI

Percutaneous Coronary Intervention (PCI) of Chronic Total Occlusions (CTO) represents the most challenging procedure in modern endovascular treatments. In recent years, the success rate of CTO PCI has substantially improved, owing to increasing operator expertise and advancements in CTO equipment and algorithms as well as the development of expert consensus documents. In this review, we summarize existing evidence for CTO PCI, its success/ risk prediction scoring tools, procedural principles and complications and provide an insight into the future role of CTO PCI.

Acute diffuse thickening like 'halo' of the coronary tunica adventitia after rotational atherectomy

Supplemental Digital Content is available in the text.

Subintimal Versus Intraluminal Approach for Femoropopliteal Chronic Total Occlusions Treated With Intravascular Ultrasound Guidance

Background

The subintimal approach (SA) is widely used in endovascular therapy for femoropopliteal chronic total occlusion lesions. However, when compared with the intraluminal approach (IA), the safety and efficacy of SA in real‐world practice are not well characterized. Furthermore, there is a paucity of data on the clinical impact of subintimal and intraluminal wire passage (SWP and IWP, respectively) assessed by intravascular ultrasound.

Methods and Results

From the IVORY (Intravascular Ultrasound‐Supported Endovascular Therapy in Superficial Femoral Artery) registry, this study included 500 patients undergoing endovascular therapy for femoropopliteal chronic total occlusion lesions (SA, n=67; IA, n=433; and SWP, n=186; IWP, n=314). The primary end point was the cumulative 1‐year incidence of restenosis. The rate of perioperative complications was also assessed. Propensity score matching analysis was performed to adjust for the intergroup differences. After propensity score matching, the final study population consisted of 59 pairs (SA, n=59; IA, n=348) and 170 pairs (SWP, n=170; IWP, n=293), respectively. Cumulative 1‐year incidence of restenosis was comparable between the SA and IA groups (41.0% versus 43.4%, P=0.40). No significant difference in 1‐year restenosis rate between the SWP and IWP groups was observed (48.2% versus 40.8%, P=0.40), although the SWP group tended to be a higher rate of perioperative complications than the IWP group (8.2% versus 4.1%, P=0.07).

Conclusions

At 1 year, both SA and IA showed acceptable results for femoropopliteal chronic total occlusion lesions. Cumulative 1‐year incidence of restenosis was not significantly different between SWP and IWP, whereas perioperative complications occurred more frequently in SWP than in IWP.

Registration

URL: https://www.umin.ac.jp; Unique identifier: UMIN000020472.

The importance of side branch preservation in the treatment of chronic total occlusions with bifurcation lesions

OBJECTIVES

The aim of this study was to identify the predictive factors for suboptimal result in side branch (SB) in chronic total occlusion (CTO) bifurcation lesions and clinical outcomes of patients with suboptimal result in SB.

BACKGROUND

There is little evidence on the optimal strategy for bifurcation lesions in CTO.

METHODS

We retrospectively reviewed 314 consecutive bifurcation lesions in CTO with SB ≥ 2.5 mm in 3 hospitals from March 2010 to June 2018. Patients were divided into the two groups based on the suboptimal SB treatment (SST) and optimal SB treatment (OST) groups. The baseline characteristics, procedural and clinical outcomes were compared between the two groups. This study also evaluated the predictors of suboptimal result in SB.

RESULTS

Suboptimal result in SB occurred in 47 cases. Presence of stenosis in SB, bifurcations located within the occluded segment and sub-intimal tracking at SB ostium was an independent predictor of suboptimal result in SB. The cumulative incidence of target lesion revascularization (TLR) in all lesions was not significantly different between the two groups, however, TLR in right coronary artery (RCA) was significantly higher in the SST group. In the Cox regression analysis, suboptimal result in SB in RCA and sub-intimal tracking were independent predictors of TLR for MB. In patients with bifurcations located within the occluded segment, usage of two-stent technique was significantly lower in the SST group.

CONCLUSIONS

Meticulous procedures are required for SB preservation to improve not only SB prognosis but also MB, especially in RCA.

Outcomes of retrograde approach for chronic total occlusions by guidewire location

BACKGROUND

Connecting the antegrade wire (AW) and the retrograde wire (RW) is a goal of chronic total occlusion (CTO) treatment, but angiographic guidewire location is sometimes misleading.

AIMS

The aim of this study was to evaluate the association between intravascular ultrasound (IVUS)-defined AW and RW position and procedural outcomes when treating CTO lesions using the retrograde approach.

METHODS

Overall, 191 CTO lesions treated using an IVUS-guided retrograde approach at three centres in Japan, China, and the USA were included.

RESULTS

When the AW and RW angiographically overlapped, four wire positions were seen on IVUS: (i) AW within the plaque (AW-intraplaque) and RW-intraplaque in 34%; (ii) AW-intraplaque and RW in the subintimal space (RW-subintima) in 28%; (iii) AW-subintima and RW-subintima in 22%; or (iv) AW-subintima and RW-intraplaque in 16%. The procedure succeeded without repositioning the wire in 89% of AW-intraplaque/RW-intraplaque, 61% of AW-intraplaque/RW-subintima and 57% of AW-subintima/RW-subintima, but only one (3%) AW-subintima/RW-intraplaque. Lesion and procedure complexity and failure/complications were greatest in AW-subintima/RW-intraplaque.

CONCLUSIONS

IVUS-identified vascular compartment concordance versus IVUS-identified vascular compartment mismatch leads to higher success rates irrespective of intraplaque or subintimal passage. AW-subintima/RW-intraplaque was associated with the most complex CTO morphology and procedure, and repositioning the wire was almost always necessary. Visual summary. When the antegrade wire is in the subintimal space and the retrograde wire is in the intraplaque, re-wiring is almost always necessary.

Stent visualization methods to guide percutaneous coronary interventions and assess long-term patency

Evaluation of acute percutaneous coronary intervention (PCI) results and long-term follow-up remains challenging with ongoing stent designs. Several imaging tools have been developed to assess native vessel atherosclerosis and stent expansion, improving overall PCI results and reducing adverse cardiac events. Quantitative coronary analysis has played a crucial role in quantifying the extent of coronary artery disease and stent results. Digital stent enhancement methods have been well validated and improved stent strut visualization. Intravascular imaging remains the gold standard in PCI guidance but adds costs and time to the procedure. With a recent shift towards non-invasive imaging assessment and coronary computed tomography angiography imaging have shown promising results. We hereby review novel stent visualization techniques used to guide PCI and assess stent patency in the modern PCI era.

[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.

Thirty-day and 5-year results of percutaneous coronary intervention for in-stent restenotic chronic total occlusion lesions: Data from 2,659 consecutive patients

OBJECTIVES

To investigate the procedure success rate and clinical outcomes of in-stent restenotic chronic total occlusion (ISR-CTO) percutaneous coronary intervention (PCI).

BACKGROUND

Few studies have reported the short- and long-term clinical outcomes of ISR-CTO PCI.

METHOD

Patients who underwent ISR-CTO (n = 212) or de-novo CTO (n = 2,447) PCI at Fuwai Hospital from 2010 to 2013 were enrolled. Thirty-day and 5-year clinical outcomes were analyzed. The primary outcome was the incidence of all-cause death, myocardial infarction (MI), and heart failure at follow-up. The secondary outcome was the recanalization result (reasonable, suboptimal, or failed recanalization).

RESULTS

ISR-CTO PCI had a higher rate of suboptimal recanalization than de-novo CTO PCI (p < .01). The syntax score before PCI (odds ratio (OR): 1.06; 95% confidence interval (CI): 1.02-1.10; p = .002) and occlusion length ≥ 20 mm (OR: 2.70:95% CI: 1.46-4.98; p = .001) were predictors of suboptimal recanalization in ISR-CTO PCI. Cardiac death (p = .03) and 30-day all-cause mortality (p = .05) were higher among patients who underwent ISR-CTO PCI. The ISR-CTO group had a higher rate of MI (p = .07) at 5 years. Suboptimal recanalization (hazard ratio: 2.56; 95% CI: 1.13-5.83; p = .025) was an independent predictor of long-term major adverse events in ISR-CTO.

CONCLUSIONS

Suboptimal recanalization, 30-day cardiac death, and long-term MI rates are higher for ISR-CTO PCI than de-novo CTO PCI. Suboptimal recanalization is an independent predictor of long-term major adverse events after ISR-CTO PCI.

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.

Predictors for adverse outcomes of patients with recanalized chronic total occlusion lesion

BACKGROUND

It is ill-defined which factors affect the prognosis of patients with recanalized chronic total occlusion (CTO). This study sought to investigate predictors for adverse outcome in such a cohort with long-time follow-up.

METHODS

From 2010 to 2013, patients with successfully recanalized CTO were included. The primary endpoint was a composite of all-cause death, myocardial infarction or target vessel revascularization (TVR). The secondary endpoints were TVR and target lesion revascularization (TLR).

RESULTS

A total of 1987 patients were enrolled and 1806 (90.6%) subjects completed 5-year follow-up. Multivariate Cox analysis revealed that age ≥ 75 years (HR,1.70; 95% CI, 1.09-2.64; P = .02), left ventricular ejection fraction <40% (HR, 1.94; 95% CI, 1.02-3.69; P = .04) and residual SYNTAX score (HR, 1.02; 95% CI, 1.01-1.04; P = .01) were predictors for the primary endpoint. Non-LAD CTO (HR, 1.82; 95% CI, 1.23-2.70; P < .01), J-CTO score (HR, 1.31; 95% CI, 1.11-1.54; P < .01) and residual SYNTAX score (HR, 1.02; 95% CI, 1.00-1.04; P = .04) were independently related to TVR. Non-LAD CTO, high J-CTO score and residual SYNTAX score was also correlated with TLR.

CONCLUSIONS

Advanced age, left ventricular dysfunction and residual SYNTAX score were predictors for composite cardiovascular events in patients with CTO after revascularization. Those with non-LAD CTO, high J-CTO and residual SYNTAX score had higher risk for revascularization.

Intravascular Ultrasound in Chronic Total Occlusion Percutaneous Coronary Intervention: Solving Ambiguity and Improving Durability

Chronic total occlusions remain among the most technically challenging lesions to treat percutaneously. Limitations of 2-dimensional angiography may further hinder successful treatment of these lesions. Intrasvascular ultrasound has a key role in percutaneous recanalization for a chronic total occlusion by providing key lesion characteristics, facilitating guidewire crossing, elucidating the intraplaque or extralaque path of the guidewire, optimizing lesion preparation, guiding stenting and identifying suboptimal results. Live visualization of the guidewire during crossing may reduce extraplaque wire tracking. This review describes the practical uses of intravascular imaging for commonly encountered scenarios when treating chronic total occlusions.

Intravascular Healing Is Not Affected by Approaches in Contemporary CTO PCI: The CONSISTENT CTO Study

OBJECTIVES

The aim of this study was to assess angiographic, imaging, and clinical outcomes following chronic total occlusion (CTO) percutaneous coronary intervention (PCI) with dissection and re-entry techniques (DART) and subintimal (SI) stenting compared with intimal techniques.

BACKGROUND

Reliable procedural success and safety in CTO PCI require the use of DART to treat the most complex patients. Potential concerns regarding the durability of DART with SI stenting still need to be addressed.

METHODS

This was a prospective, multicenter, single-arm trial of patients with appropriate indications for CTO PCI.

RESULTS

Successful CTO PCI was performed in 210 of 231 patients (91% success). At 1 year, the primary endpoint of target vessel failure (cardiac death, myocardial infarction related to the target vessel, or any ischemia-driven revascularization) occurred in 5.7% of patients, meeting the pre-set performance goal. Major adverse cardiovascular events (all-cause mortality, myocardial infarction, or target vessel revascularization) occurred in 10% at 1 year and 17% by 2 years and was not influenced by DART. Quality-of-life measures significantly improved from baseline to 12 months. There was no difference in intravascular healing assessed using optical coherence tomography at 12 months for patients treated with DART and SI stenting compared with intimal strategies.

CONCLUSIONS

Contemporary CTO PCI is associated with medium-term clinical outcomes comparable with those achieved in other complex PCI cohorts and significant improvements in quality of life. The use of DART with SI stenting does not adversely affect intravascular healing at 12 months or medium-term major adverse cardiovascular events. (Consistent CTO Trial; NCT02227771).

Intravascular Imaging-Guided Percutaneous Coronary Intervention

Despite consistent clinical data supporting the use of intravascular imaging with percutaneous coronary intervention, utilization remains low. A practical and standardized approach to incorporating intravascular imaging with percutaneous coronary intervention may overcome the barriers to utilization. This review focuses on basic image interpretation with intravascular ultrasound and optical coherence tomography and proposes an algorithmic approach to stent sizing and optimization. Incorporation of this strategic method for percutaneous coronary intervention may aid in the greater adoption of intravascular imaging for percutaneous coronary intervention.

The role of intravascular ultrasound in percutaneous coronary intervention of complex coronary lesions

Intravascular ultrasound (IVUS) is a catheter-based coronary imaging technique. It utilises the emission & subsequent detection of reflected high frequency (30-60 MHz) sound waves to create high resolution, cross-sectional images of the coronary artery. IVUS has been the cornerstone of intracoronary imaging for more than two decades. When compared to the invasive coronary angiogram which studies only the silhouette of the contrast-filled artery lumen, IVUS also crucially images the vessel wall. Because of this capability, IVUS has greatly facilitated understanding of the coronary atherosclerosis process. Such insights from IVUS reveal how commonly and extensively plain angiography underestimates the true extent of coronary plaque, the characteristics of plaques prone to rupture and cause acute coronary syndromes (lipid rich, thin cap atheroma), and a realisation of the widespread occurrence of vessel remodelling in response to atherosclerosis. Similarly, IVUS has historically provided salutary mechanistic insights that have guided many of the incremental advances in the techniques of percutaneous coronary intervention (PCI). Examples include mechanisms of in-stent restenosis, and the importance of high-pressure post-dilatation of stents to ensure adequate stent apposition and thereby reduce the occurrence of stent thrombosis. IVUS also greatly facilitates the choice of correct diameter and length of stent to implant. Overall, a compelling body of evidence indicates that use of intravascular ultrasound in PCI helps to achieve optimal technical results and to mitigate the risk of adverse cardiac events. In this review, the role of intravascular ultrasound as an adjunct to PCI in complex coronary lesions is explored. The complex coronary situations discussed are the left main stem, ostial stenoses, bifurcation stenoses, thrombotic lesions, the chronically occluded coronary artery, and calcified coronary artery disease. By thorough review of the available evidence, we establish that the advantages of IVUS guidance are particularly evident in each of these complex CAD subsets. In particular, some consider the use of IVUS to be almost mandatory in left main PCI. A comparison with other intracoronary imaging techniques is also explored.

Prognostic significance of occlusion length in recanalized chronic total occlusion lesion: a retrospective cohort study with 5-year follow-up

OBJECTIVES

This study sought to investigate the relationship between occlusion length and long-term outcomes of patients with recanalised chronic total occlusion (CTO) lesion.

DESIGN

A retrospective cohort study.

SETTING

Fuwai Hospital, National Center for Cardiovascular Disease, Beijing, China PARTICIPANTS: Consecutive patients with successfully recanalised CTO were included from January 2010 to December 2013.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary endpoint of the present study was a composite event of all-cause death and myocardial infarction (MI). The secondary endpoints included target lesion revascularisation (TLR) and target vessel revascularisation (TVR).

RESULTS

A total of 1987 patients were included and 1801 (90.6%) subjects completed 5-year follow-up in this study. Based on occlusion length, the patients were divided equally into two groups: short (length <15 mm, n=957) and long (length ≥15 mm, n=1030) CTO group. Kaplan-Meier survival curve showed no significant difference in the risk of the composite primary endpoint between short and long CTO groups (p=0.242). Receiver operating characteristic curve analysis also established occlusion length ≥15 mm as a cut-off value for predicting TLR and TVR, with an area under the curve of 0.604 (95% CI: 0.569 to 0.638, p<0.001) and 0.605 (95% CI: 0.572 to 0.638; p<0.001). Kaplan-Meier analysis revealed that the risks for TLR (p=0.002) and TVR (p=0.002) were higher in a patient with long CTO lesion. Multivariate Cox analysis also identified long CTO lesion as an independent predictor of TLR (HR: 1.539, 95% CI: 1.033 to 2.293; p=0.034) and TVR (HR: 1.476, 95% CI: 1.012 to 2.151; p=0.043).

CONCLUSION

Patients with long CTO lesion did not show a higher risk of death and MI after recanalisation, but had higher risks of TLR and TVR. Lesion with occlusion length ≥15 mm should be under close surveillance for restenosis after recanalisation.

Procedural outcomes of chronic total occlusion percutaneous coronary intervention in patients with dissection and reentry versus wire escalation techniques: a meta-analysis

BACKGROUND

The procedural safety of dissection and reentry (DR) techniques in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) remains controversial, when compared with conventional wire escalation (WE) techniques. The meta-analysis was performed to evaluate the impact of DR techniques vs. WE techniques on periprocedural outcomes in patients with CTO undergoing PCI.

METHODS

Studies were searched in electronic database from inception to December 2018. Results were pooled using random effects model and fixed effects model.

RESULTS

The pooled analyses revealed that DR techniques increased risks of periprocedural complications in patients with CTO PCI, including higher coronary perforation rate [risk ratio (RR) = 2.10, 95% confidence interval (CI) 1.24-3.55], periprocedural myocardial infarction (RR = 1.85, 95% CI 1.23-2.78), branch occlusion (RR = 2.69; 95% CI 1.92-3.77) and coronary hematoma (RR = 3.06; 95% CI 2.45-3.82) detected by intravascular ultrasound, when compared to those with WE techniques. However, DR techniques were more applied in patients with higher complexity CTO lesions, which was evidenced by higher J-CTO score [standard mean differences (SMD) = 0.71, 95% CI 0.51-0.91] and longer fluoroscopy time (SMD = 0.93, 95% CI 0.70-1.16), that may explain the higher complications rates in the DR techniques group as compared with WE techniques.

CONCLUSION

The present meta-analysis suggests that the DR technique is relatively frequently used during contemporary CTO PCI, especially for challenging more complex CTO lesions. However, it is associated with higher, yet acceptable, rates of periprocedural adverse events as compared with a conventional WE strategy. Further refinement of DR techniques and evidence from large RCTs is needed to define the optimal role of DR in hybrid CTO PCI.

Antegrade Chronic Total Occlusion Strategies: A Technical Focus for 2020

Chronic total occlusions (CTOs) are common in patients with ischaemic heart disease. In many countries, patients with CTOs are underserved by percutaneous coronary intervention (PCI). One of the barriers to CTO PCI is the technical challenges of these procedures. Improvements in technique and dedicated devices for CTO PCI, combined with advances in procedural strategy, have resulted in a dramatic increase in procedural success and outcomes. Antegrade wiring (AW) is the preferred initial strategy in short CTOs, where the proximal cap and course of the vessel is understood. For many longer, more complex occlusions, AW has a low probability of success. Dissection and re-entry techniques allow longer CTOs and those with ambiguous anatomy to be crossed safely and efficiently, and CTO operators must also be familiar with these strategies. The CrossBoss and Stingray system is currently the primary targeted re-entry device used during antegrade dissection and re-entry (ADR), and there continues to be an evolution in its use to increase procedural efficiency. In contrast to older ADR techniques, targeted re-entry allows preservation of important side-branches, and there is no difference in outcomes compared to intraplaque stenting.

The impact of dissection and re-entry versus wire escalation techniques on long-term clinical outcomes in patients with chronic total occlusion lesions following percutaneous coronary intervention: An updated meta-analysis

BACKGROUND

The meta-analysis was performed to evaluate the effect of dissection and re-entry (DR) vs. wire escalation (WE) techniques on long-term clinical outcomes in patients with chronic total occlusion (CTO) lesions undergoing percutaneous coronary intervention.

METHODS

Studies were searched in electronic databases from inception to September, 2019. Results were pooled using random effects model and fixed effects model and are presented as risk ratios (RR) with 95% confidence intervals (CI).

RESULTS

Pooled analyses revealed that patients with DR techniques had overall higher complexity CTO lesions than patients with WE techniques and required a greater number of stents and a greater mean stent length. The "extensive" DR techniques may have a higher incidence of target vessel revascularization (TVR) (RR = 2.30, 95% CI: 1.77-2.98), in-stent restenosis (RR = 1.71, 95% CI: 1.30-2.23), in-stent reocclusion (RR = 1.86, 95% CI: 1.03-3.3) and death/myocardial infarction/TVR (RR = 2.10, 95% CI: 1.71-2.58), when compared with WE techniques, during the long-term follow-up. However, "limited" DR techniques result in more promising outcomes, and are comparable to conventional WE techniques.

CONCLUSIONS

Dissection and re-entry techniques were associated with increased risk of long-term negative clinical events, especially "extensive" DR techniques. However, "limited" DR techniques resulted in good long-term outcomes, comparable to WE techniques.

Chronic total occlusions-Is true lumen wire passage preferred to subintimal dissection re-entry?

True lumen crossing is superior to subintimal crossing. Subintimal versus true lumen crossing may only be apparent if IVUS is performed. Newer techniques for true lumen crossing need to be developed.

Adverse events in patients with high platelet reactivity following successful chronic total occlusion PCI: The Assessment of Dual AntiPlatelet Therapy with Drug-Eluting Stents (ADAPT-DES) study

BACKGROUND

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) typically requires a greater number of stents and longer stent length than non-CTO PCI, placing these patients at greater risk for adverse ischemic events. We sought to determine whether the association between high platelet reactivity (HPR) and the risk of ischemic events is stronger after CTO than non-CTO PCI.

METHODS

Patients undergoing successful PCI in the multicenter ADAPT-DES study were stratified according to whether they underwent PCI of a CTO. HPR was defined as VerifyNow platelet reaction units >208. The study primary endpoint was the 2-year risk target vessel failure ([TVF] defined as cardiac death, myocardial infarction, or target lesion revascularization).

RESULTS

CTO PCI was performed in 400 of 8448 patients. HPR was present in 34.5% of CTO PCI patients and 43.1% of non-CTO PCI patients (P = .0007). Patients undergoing CTO PCI with versus without HPR had significantly higher 2-year rates of TVF (15.0% versus 8.3%, P = .04) without significant differences in bleeding. HPR was an independent predictor of 2-year TVF (adjusted HR 1.16, 95% CI 1.02-1.34, P = .03) whereas CTO PCI was not (adjusted HR 0.89, 95% CI 0.65-1.22, P = .48). There was a significant interaction between CTO versus non-CTO PCI and PRU as a continuous variable for 2-year TVF (P_interaction = 0.02).

CONCLUSIONS

In ADAPT-DES, HPR was associated with an increased 2-year risk of TVF after PCI, an association that was at least as strong after CTO PCI compared with non-CTO PCI.

The antegrade dissection and re-entry technique as preparation of intravascular ultrasound guided re-wiring

Although the antegrade dissection and re-entry technique (ADR) with Stingray system is one of the procedures for percutaneous coronary intervention (PCI) of chronic total occlusion (CTO), it has some risk of side-branch occlusion. This article reports a CTO case in the left circumflex artery successfully treated with combination use of ADR subintimal tracking and intravascular ultrasound (IVUS)-guided re-wiring without side-branch occlusion. Antegrade approach with single-wire and parallel-wire technique was failed. Retrograde approach through ipsilateral collateral was also failed. Therefore, the ADR was attempted and Stingray wire crossed through at the distal site of posterolateral (PL) branch. To avoid PL branch occlusion, IVUS-guided re-wiring to the true lumen was attempted. Finally, the CTO lesion was recanalized without any complication and 1 year follow-up angiography had good result. ADR as preparation of IVUS-guided re-wiring might be one of the useful procedures for those complex CTO cases.

A Technical Focus on Antegrade Dissection and Re-entry for Coronary Chronic Total Occlusions: a Practice Update for 2019

Coronary chronic total occlusions (CTOs) are a commonly encountered lesion. These present in a diverse patient population with variable anatomy. Technical success rates of ~90% are achievable for CTO lesions in centers with appropriate expertise. Many lesions can be crossed with wire-based techniques. However, the most anatomically complex and technically challenging lesions will often require more advanced approaches such as retrograde access and/or the application of blunt dissection techniques in the vessel to safely navigate long and/or ambiguous CTO segments. Retrograde dissection and re-entry (RDR) and antegrade dissection and re-entry (ADR) strategies are often needed to treat such lesions. In many circumstances, ADR offers a safe and efficient means to successfully cross a CTO lesion. Therefore, operators must remain cognizant of the risks and benefits of differing technical approaches during CTO percutaneous coronary intervention, particularly when both ADR and RDR are feasible. This article provides an overview of the ADR technique in addition to updated approaches in contemporary clinical practice.