Approach for Chronic Total Occlusion With Intravascular Ultrasound-Guided Reverse Controlled Antegrade and Retrograde Tracking Technique: Single Center Experience

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.

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.

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.

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.

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.

When to use intravascular ultrasound or optical coherence tomography during percutaneous coronary intervention?

Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) are intravascular imaging technologies widely used in the cardiac catheterization laboratory. The impact of these modalities for optimizing the acute and longer-term clinical impact following percutaneous coronary intervention (PCI) is supported by a wealth of clinical evidence. Intravascular imaging provides unique information for enhanced lesion preparation, optimal stent sizing, recognizing post PCI complications, and the etiology of stent failure. This review compares and contrasts the key aspects of these imaging modalities during PCI.

Contemporary practices using intravascular imaging guidance with IVUS or OCT to optimize percutaneous coronary intervention

Introduction: Angiography is routinely used to perform percutaneous coronary intervention (PCI). However, angiography has many limitations that prevent accurate assessment of coronary lesions. The development and evolution of intravascular imaging have offset the limitations of angiography. Overwhelming evidence supports intravascular imaging guidance to optimize PCI results and studies have shown that it is associated with better outcomes. Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) are the most commonly used modalities and both have far greater spatial resolution compared with angiography. There are advantages and disadvantages to both IVUS and OCT, and the optimal modality will depend on patient factors and indications.Areas covered: This review will summarize clinical evidence and current practices in the use of intravascular imaging in PCI. Literature review from year 2000-2019 was completed via PubMed search using keywords.Expert commentary: Intravascular imaging is an essential tool in PCI that has outcome implications, but it is still underutilized. Proper image acquisition, accurate interpretation, and correct decision-making are needed for patients to benefit from imaging-guided PCI. Training and education are essential in successful utilization of imaging technology. High-definition IVUS is likely to gain favor as there is improved image resolution without the use of contrast.

A comparison of procedural success rate and long-term clinical outcomes between in-stent restenosis chronic total occlusion and de novo chronic total occlusion using multicenter registry data

Background

There have been little data about outcomes of percutaneous coronary intervention (PCI) for in-stent restenosis (ISR) chronic total occlusion (CTO) in the drug eluting stent (DES) era. This study aimed to compare the procedural success rate and long-term clinical outcomes of ISR CTO and de novo CTO.

Methods and results

Patients who underwent PCI for ISR CTO (n = 164) versus de novo CTO (n = 1208) were enrolled from three centers in Korea between January 2008 and December 2014. Among a total of ISR CTO, a proportion of DES ISR CTO was 79.3% (n = 130). The primary outcome was major adverse cardiac events (MACEs); a composite of all-cause death, non-fatal myocardial infarction (MI), or target lesion revascularization (TLR). Following propensity score-matching (1:3), the ISR CTO group (n = 156) had a higher success rate (84.6% vs. 76.0%, p = 0.035), mainly driven by high success rate of PCI for DES ISR CTO (88.6%), but showed a higher incidence of MACEs [hazard ratio (HR): 2.06; 95% confidence interval (CI) 1.37–3.09; p < 0.001], mainly driven by higher prevalence of MI [HR: 9.71; 95% CI 2.06–45.81; p = 0.004] and TLR [HR: 3.04; 95% CI 1.59–5.81; p = 0.001], during 5 years of follow-up after successful revascularization, as compared to the de novo CTO group (n = 408).

Conclusion

The procedural success rate was higher in the ISR CTO than the de novo CTO, especially in DES ISR CTO. However, irrespective of successful revascularization, the long-term clinical outcomes for the ISR CTO were significantly worse than those for the de novo CTO, in terms of MI and TLR.

Graphic abstract

Imaging during percutaneous coronary intervention for optimizing outcomes

Angiography is the current gold standard for imaging during percutaneous coronary interventions but has significant limitations. Catheter-based intravascular imaging techniques such as intravascular ultrasound and the more recent optical coherence tomography have the potential to overcome these limitations and thus optimize clinical outcomes. In this update, we discussed the current applications of the available imaging techniques, existing evidence, continuing unmet needs, and potential areas for further research.

Usefulness and Safety of a Novel Modification of the Retrograde Approach for the Long Tortuous Chronic Total Occlusion of Coronary Arteries

The aim of this study was to evaluate the feasibility and efficacy of the Guidezilla guide extension catheter in a reverse controlled antegrade and retrograde subintimal tracking (CART) technique for chronic total occlusion (CTO) recanalization.We retrospectively collected 80 CTO cases using reverse CART technology from January 2015 to October 2015 and 20 CTO cases using Guidezilla reverse-CART technology from October 2015 to March 2016. Guidezilla was applied in cases when it was difficult to advance a retro-guidewire through an occlusion segment into the antegrade guide catheter.The Guidezilla group had more cases with an occlusion longer > 20 mm (100.0% versus 72.5%, P = 0.005) and "bending > 45°" (90.0% versus 63.7%, P = 0.029) than the non-Guidezilla group, while the non-Guidezilla group had more retry lesions (25.0% versus 63.8%, P = 0.002). The septal collateral channel was the preferred choice for retro-recanalization in both groups (90.0% in Guidezilla group and 68.8% in non-Guidezilla group). All cases in the Guidezilla group achieved technical success with a TIMI 3 flow in the distal true lumen (100.0% versus 75.0% in non-Guidezilla group, P = 0.010). Cardiac tamponade and perforation in the epicardial artery was observed in 1 case each in the Guidezilla group. In the non-Guidezilla group, 19 complications occurred during the PCI procedure. No target vessel revascularization or in-hospital death occurred in either group.CTO lesions using the Guidezilla guide extension catheter to facilitate entry to an antegrade catheter in reverse CART technology is convenient and safe with a high success rate.

Controlled antegrade intimal tracking with subintimal balloon inflation as a novel bailout technique for chronic total occlusion after failed intravascular ultrasound-guided parallel wire technique

Failure to cross with a guidewire is the most common reason for failure of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). In cases of CTO PCI with no interventional collaterals, an intravascular ultrasound (IVUS)-guided parallel wire technique is usually the last-resort procedure. Failure of this technique sometimes causes enlarged subintimal space, resulting in procedure failure. We present a successful second attempt at left anterior descending artery CTO PCI with no interventional collaterals. After IVUS-guided parallel wire technique failed with an enlarged subintimal space, successful antegrade wire crossing was achieved using controlled antegrade intimal tracking with balloon inflation in the subintimal space to deflect a second wire. This technique may be useful as a bailout strategy in otherwise-failed CTO PCI with an enlarged subintimal space.

Use of Intravascular Imaging During Chronic Total Occlusion Percutaneous Coronary Intervention: Insights From a Contemporary Multicenter Registry

BACKGROUND

Intravascular imaging can facilitate chronic total occlusion (CTO) percutaneous coronary intervention.

METHODS AND RESULTS

We examined the frequency of use and outcomes of intravascular imaging among 619 CTO percutaneous coronary interventions performed between 2012 and 2015 at 7 US centers. Mean age was 65.4±10 years and 85% of the patients were men. Intravascular imaging was used in 38%: intravascular ultrasound in 36%, optical coherence tomography in 3%, and both in 1.45%. Intravascular imaging was used for stent sizing (26.3%), stent optimization (38.0%), and CTO crossing (35.7%, antegrade in 27.9%, and retrograde in 7.8%). Intravascular imaging to facilitate crossing was used more frequently in lesions with proximal cap ambiguity (49% versus 26%, P<0.0001) and with retrograde as compared with antegrade-only cases (67% versus 31%, P<0.0001). Despite higher complexity (Japanese CTO score: 2.86±1.19 versus 2.43±1.19, P=0.001), cases in which imaging was used for crossing had similar technical and procedural success (92.8% versus 89.6%, P=0.302 and 90.1% versus 88.3%, P=0.588, respectively) and similar incidence of major cardiac adverse events (2.7% versus 3.2%, P=0.772). Use of intravascular imaging was associated with longer procedure (192 minutes [interquartile range 130, 255] versus 131 minutes [90, 192], P<0.0001) and fluoroscopy (71 minutes [44, 93] versus 39 minutes [25, 69], P<0.0001) time.

CONCLUSIONS

Intravascular imaging is frequently performed during CTO percutaneous coronary intervention both for crossing and for stent selection/optimization. Despite its use in more complex lesion subsets, intravascular imaging was associated with similar rates of technical and procedural success for CTO percutaneous coronary intervention.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02061436.

Chronic total coronary occlusion recanalization: Current techniques and new devices

Percutaneous coronary intervention (PCI) of total chronic coronary occlusion (CTO) still remains a major challenge. The prevalence of a CTO has been reported to be up to 30% among patients with a clinical indication for coronary angiography. Progress has been made with further advanced interventional techniques and continuously sophisticated interventional tools. Nevertheless the number of interventions carried out to recanalize a CTO is less than 10% of all procedures. Benefits of a successful CTO recanalization include relief of angina pectoris and ischemia-related dyspnea, substantial improvement in left ventricular function and, avoidance of surgery treatment. A vast variety of new CTO PCI techniques and materials has been introduced into clinical practise and pushed success rates of reopening a CTO up to around 90% in experienced hands. Particulary the introduction of the retrograde technique was a milestone. New developed microcatheters and special polymer coated wires allow to recanalize via small collaterals and vessels. Other tools such as intravascular ultrasound (IVUS) and multislice computertomography (MSCT) help to identify the anatomy and the characteristic of the lesions. Any invasive cardiac center should adopt CTO PCI procedures as standard therapy.

Objective

This review wants to assess and describe the latest development in CTO recanalization strategies.

Intravascular Ultrasound Guided Percutaneous Coronary Intervention for Chronic Total Occlusion

Chronic total occlusion (CTO), a fascinating and dynamic niche in the realm of coronary artery disease, represents a major technical challenge for interventional cardiologists despite evolution of better guidewires, devices, experience and techniques. Effective wiring technique is the corner stone to success of percutaneous coronary intervention (PCI) in CTO. As a guide for guidewire crossing in CTO, coronary angiography is limited. On the other hand, intravascular ultrasound (IVUS) enhances the ability to identify coronary anatomy, the exact location of the guidewires within an artery, discriminating a true lumen from the false lumen before guidewire crossing. Some angiographic features have been suggested to be predictive of procedural failure, including blunt stump with a side branch at the site of occlusion. Novel use of IVUS can recognize the optimal entry point and evaluate if a guidewire properly penetrates the proximal cap of CTO.

Prevention of contrast-induced acute kidney injury after percutaneous coronary intervention for chronic total coronary occlusions

Chronic total occlusions (CTOs) represent a major challenge in percutaneous coronary revascularization. The recent advances in strategies and techniques and the development of dedicated equipment, such as microcatheters and wires, have resulted in considerably higher success rates. Although successful CTO recanalization is associated with significant clinical benefits, including improvement of angina, quality of life, reduced need for surgical revascularization, and improvement of left ventricular function, CTO procedures may require prolonged x-ray exposure and use of larger volumes of contrast compared with non-CTO procedures. Large volumes of contrast medium have been associated with increased rates of contrast-induced acute kidney injury (CI-AKI) and adverse short- and long-term outcomes. Application of specific measures and algorithms should be considered by all CTO operators to prevent CI-AKI.

First reported revascularization of complex occlusion of the right coronary artery using the IVUS-guided reverse CART technique via a gastroepiploic artery graft

When patients who have previously undergone coronary artery bypass graft surgery develop ischemia symptoms that cannot be controlled by optimal medical therapy, repeat revascularization is indicated. The revascularization strategy should be based on individual clinical and anatomical characteristics. We report here a challenging patient who presented with recurrent stable angina due to worsening of a proximal right coronary artery (RCA) stenosis to chronic total occlusion (CTO) after anastomosis of the right gastroepiploic artery (GEA) to the posterior descending artery. A soft guidewire was advanced through the right GEA collateral channel to the distal end of the CTO, but the dedicated CTO guidewires could not be advanced across the severely calcified CTO using the retrograde wire crossing or kissing wire techniques. The RCA was eventually revascularized by implantation of drug-eluting stents using the intravascular ultrasound-guided reverse controlled antegrade and retrograde subintimal tracking technique.

Impact of Intravascular Ultrasound in Clinical Practice

Intravascular ultrasound (IVUS) has expanded our understanding of atherosclerotic plaque morphology, and provides an opportunity to guide cardiovascular interventions and evaluate results. Use of this technique requires understanding of ultrasound physics, catheter differences, skills in vessel, plaque and stent quantification and knowledge of artifacts and various physiologic and pathologic findings. Optimal cardiovascular interventions should result in absence of inflow or outflow obstruction, precise geographic landing, while attaining the largest feasible luminal gain without plaque protrusion, vessel dissection or perforation and, if deployed, with complete stent expansion and apposition to the vessel wall. IVUS is safe, cost efficient and effectively optimises cardiovascular interventions. In addition, IVUS improves outcomes when used to guide coronary interventions using bare metal stents (BMS) and drug eluting stents (DES). The role of IVUS in endovascular therapy is rapidly expanding. This review will focus on the impact of IVUS in clinical practice.