Optical coherence tomography findings after chronic total occlusion interventions: Insights from the “AngiographiC evaluation of the everolimus-eluting stent in chronic Total occlusions” (ACE-CTO) study (NCT01012869)

Self-Apposing Stents in Coronary Chronic Total Occlusions: A Pilot Study

OBJECTIVES

This pilot study assessed the 12-month angiographic and clinical outcomes of self-apposing (SA) stents in patients undergoing chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

BACKGROUND

Self-apposing (SA) stents may decrease incomplete strut apposition and stent strut coverage that are common after CTO PCI.

METHODS

We compared 20 patients who underwent CTO PCI using SA drug-eluting stents (DESs) with 20 matched control patients who underwent CTO PCI using balloon-expandable (BE)-DESs. All patients were followed up clinically for 12 months and had coronary angiography with optical coherence tomography at the end of the follow-up period. The primary end points were stent strut malapposition and strut coverage. The secondary end point was composite major adverse cardiovascular events (MACEs) at 12 months.

RESULTS

Both groups had high prevalence of diabetes mellitus, and most of the treated lesions were complex, with 62% having a J-CTO score of ≥3. All CTO PCI techniques were allowed for recanalisation, and 75% of the procedures were guided by intravascular ultrasound. At 12 months, the SA-DES group had fewer malapposed struts (0% [interquartile range (IQR) 0%-0%] vs 4.5% [IQR 0%-20%]; p<0.001) and uncovered struts (0.08% [IQR 0%-1.6%] vs 8.2% [IQR 0%-16%]; p<0.001). However, they showed significantly higher rates of MACEs due to clinically-driven target lesion revascularisation (45% vs 15%; p=0.038).

CONCLUSIONS

In this pilot study, compared with conventional BE-DESs, SA-DESs used in CTO PCI were associated with fewer malapposed and uncovered stent struts but also with significantly higher rates of in-stent restenosis and MACEs, mainly caused by clinically driven target lesion revascularisation.

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.

The Bioengineered Combo Dual-Therapy CD34 Antibody-Covered Sirolimus-Eluting Coronary Stent in Patients with Chronic Total Occlusion Evaluated by Clinical Outcome and Optical Coherence Tomography Imaging Analysis

We sought to determine the effects of the use of a Bioengineered Combo Dual-Therapy CD34 Antibody-Covered Sirolimus-Eluting Coronary Stent (Combo^® DTS) in patients with chronic total occlusion (CTO) by evaluating clinical outcomes and by performing an optical coherence tomography (OCT) analysis. We retrospectively analyzed data from 39 patients who had successfully undergone OCT-guided revascularization of a CTO being treated with a Combo^® DTS. Clinical assessment, angiography (with quantitative coronary angiography analysis) and OCT examination were performed at baseline and at follow-up. The median follow-up period was 189 days, ranging from 157 to 615 days. At follow-up, revascularization was required due to angiographic restenosis in 40% (14 of 35) of patients. OCT analysis detected neointima proliferation in 23 (76.6%) patients. Neointima formation was often associated with microvessels in 18 patients (60%). Neoatheroslcerosis was observed in 2 (6.6%) patients. Malapposition was found in 4 patients (13.3%), and stent fractures were found in 11 patients (36.6%). Rate of strut coverage was 96.3% at follow-up. In conclusion, the implantation of a Combo^® DTS after successful CTO recanalization was associated with a restenosis rate of 40% despite good stent implantation at baseline, proven by OCT. Neointima formation was found as a main contributor to restenosis. Nevertheless, we observed a low rate of major cardiovascular events in our follow-up.

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).

The Orsiro Ultrathin, Bioresorbable-Polymer Sirolimus-Eluting Stent: A Review of Current Evidence

Advances in stent design and the development of bioresorbable polymers have allowed the development of novel stent technologies such as the Orsiro bioresorbable-polymer sirolimus eluting stent (BP-SES). Over several noninferiority trials, the BP-SES has demonstrated itself to be a safe and effective therapy for obstructive coronary artery disease. This article reviews the current evidence of the efficacy of the BP-SES and examines its performance in high-risk populations, such as patients presenting with ST-segment myocardial infarction, chronic total occlusions, diabetes, and small vessel disease.

Subintimal Versus Intraplaque Recanalization of Coronary Chronic Total Occlusions: Mid-Term Angiographic and OCT Findings From the ISAR-OCT-CTO Registry

OBJECTIVES

The aim of this study was to compare angiographic and optical coherence tomography findings following subintimal as opposed to intraplaque recanalization of chronic total occlusions (CTOs).

BACKGROUND

There is ongoing controversy regarding outcomes of intraplaque versus subintimal CTO recanalization.

METHODS

Consecutive patients undergoing angiography and intravascular optical coherence tomography following CTO recanalization were included in the ISAR-OCT-CTO (Intracoronary Stenting and Angiographic Results - Optical Coherence Tomography for Chronic Total Occlusions) registry. The study endpoints were percent diameter stenosis and late lumen loss as well as rate of uncovered and malapposed struts. Independent correlates of uncovered and malapposed struts were assessed by multivariate analysis.

RESULTS

The study included 75 patients. Intraplaque and dissection and re-entry techniques (DART) were used in 46 and 29 patients, respectively. There were no differences in terms of in-segment percent diameter stenosis (median 36.9 [interquartile range (IQR): 26.4 to 43.1] vs. 31.2 [IQR: 23.2 to 49.5]; p = 0.656), in-stent late lumen loss (0.215 mm [IQR: 0.063 to 0.495 mm] vs. 0.230 mm [IQR: 0.060 to 0.645 mm]; p = 0.837), or in-segment late lumen loss (0.030 mm [IQR: -0.278 to 0.510 mm] vs. 0.130 mm [IQR: -0.120 to 0.500 mm]; p = 0.395) at follow-up between the 2 techniques. Optical coherence tomography analysis showed comparable strut coverage (79.9% vs. 71.3%; p = 0.255) but significantly higher strut malapposition (6.6% vs. 13.6%; p < 0.001) following DART. Use of DART independently correlated with presence of strut malapposition (odds ratio: 3.41; 95% confidence interval: 1.24 to 9.36; p = 0.017) but not of strut coverage (odds ratio: 0.65; 95% confidence interval: 0.28 to 1.49; p = 0.314).

CONCLUSIONS

Intraplaque and subintimal recanalization techniques are associated with comparable mid-term angiographic results. Although the rate of uncovered struts is high following CTO recanalization, the recanalization technique does not independently correlate with presence of uncovered struts. There is a high rate of strut malapposition following CTO recanalization, particularly if achieved by means of DART.

Contemporary Approach to Chronic Total Occlusion Interventions

PURPOSE OF REVIEW

Chronic total occlusion (CTO) poses one of the greatest technical challenges to interventional cardiologists. Despite recent advancements in techniques and clinical trials showing significant benefits of CTO percutaneous coronary interventions (PCI), the proportion of patients with untreated CTOs remains high. We therefore aim to perform a comprehensive review of the various techniques available, recent advancements, benefits, and complications associated with CTO PCI.

RECENT FINDINGS

Three randomized clinical trials examining the benefits of CTO PCI have recently been presented. Scoring systems have been developed to facilitate pre-procedural estimation of success and complications of CTO PCI. Technological enhancements in coronary wires and other interventional equipment along with dedicated training for CTO operators have improved the likelihood of successful recanalization of CTOs. CTO PCI has been shown to improve patient symptoms and quality of life. It is therefore important to have an in-depth knowledge of the various CTO techniques, appropriate equipment, and complications when performing these complex procedures. Clinicians should weigh the risks and benefits and choose the appropriate patient population who may benefit from revascularization.

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.

Randomized Multicenter Trial Investigating Angiographic Outcomes of Hybrid Sirolimus-Eluting Stents With Biodegradable Polymer Compared With Everolimus-Eluting Stents With Durable Polymer in Chronic Total Occlusions: The PRISON IV Trial

OBJECTIVES

The aim of this study was to investigate the efficacy and safety of the hybrid ultrathin-strut sirolimus-eluting stent (SES) with biodegradable polymer compared with the thin-strut everolimus-eluting stent (EES) with durable polymer in successfully recanalized chronic total occlusions (CTOs).

BACKGROUND

The introduction of drug-eluting stents revolutionized the treatment of CTOs. However, limited data are available on new-generation drug-eluting stents with biodegradable polymer in CTOs.

METHODS

In this multicenter trial, patients were randomized, after successful CTO recanalization, to either SES or EES. The primary noninferiority endpoint was in-segment late lumen loss (noninferiority margin 0.2 mm). Secondary endpoints included in-stent late lumen loss and clinical endpoints.

RESULTS

Overall, 330 patients were included. At 9 months, angiography was available in 281 patients (85%). Duration of occlusion ≥3 months was 92.5%, with mean stent length of 52.4 ± 28.1 mm versus 52.3 ± 26.5 mm in the SES and EES groups. The primary noninferiority endpoint, in-segment late lumen loss, was not met for SES versus EES (0.13 ± 0.63 mm vs. 0.02 ± 0.47 mm; p = 0.08, 2-sided; difference 0.11 mm; 95% confidence interval: -0.01 to 0.25 mm; p_{noninferiority} = 0.11, 1-sided). In-stent late lumen loss was comparable between SES and EES (0.12 ± 0.59 mm vs. 0.07 ± 0.46 mm; p = 0.52). The incidence of in-stent and in-segment binary restenosis was significantly higher with SES compared with EES (8.0% vs. 2.1%; p = 0.028), with comparable rates of reocclusions (2.2% vs. 1.4%; p = 0.68). Clinically indicated target lesion and target vessel revascularization (9.2% vs. 4.0% [p = 0.08] and 9.2% vs. 6.0% [p = 0.33]), target vessel failure (9.9% vs. 6.6%; p = 0.35), and definite or probable stent thrombosis (0.7% vs. 0.7%; p = 1.00) were comparable between the SES and EES groups.

CONCLUSIONS

This randomized trial failed to show noninferiority of hybrid SES relative to EES in terms of in-segment late lumen loss in successfully recanalized CTOs. Furthermore, a statistically significantly higher rate of binary restenosis was found with SES.

Bioresorbable vascular scaffolds in coronary chronic total occlusions revascularization: safety assessment related to struts coverage and apposition in 6-month OCT follow-up

Beneficial properties of bioresorbable vascular scaffolds (BVS) regarding to vasomotility restoration and no caging of the vessel make them attractive devices in chronic total occlusions (CTO) revascularization. However, more evidence is needed attending to their use in this specific setting. We aim to determine feasibility and safety of BVS use in CTO revascularization attending to struts coverage and apposition, as well as re-stenosis and stent thrombosis (ST) rates. 29 BVS were deployed in 9 CTO lesions revascularization (mean J-CTO score ≥3) with an acute procedural success rate of 100%. Clinical and angiographic follow-up was performed 6 months later, including intracoronary analyses from optical coherence tomography (OCT) images. 44,723 struts were analyzed within the total 636 mm of scaffolded vessel. Mean length scaffolded per lesion was 70.66 ± 31.01 mm with a mean number of 3.22 BVS. 2051 struts (4.59%) were identified as uncovered, being most of them (98.4%) neither malapposed nor disrupted. Mean thickness of struts' coverage was 0.13 ± 0.05 mm. Incomplete strut apposition (ISA) percentage was 0% as no malapposed struts were detected and 134 struts were identified as disrupted, which represents a 0.29% from the total. Mean vessel, scaffold, and lumen diameters were 3.87 ± 0.51, 2.97 ± 0.49, and 2.68 ± 0.50 mm, respectively. Neither in-stent re-stenosis nor ST was detected. During follow-up, none of our patients died, suffered from stroke or needed target lesion revascularization. Clinical and angiographic 6-month follow-up (including OCT analyses) of BVS in CTO revascularization suggests their effectiveness and safety, even in very complex chronic occluded lesions. Nevertheless, more evidence is needed.

Approach to CTO Intervention: Overview of Techniques

OPINION STATEMENT

Successful percutaneous coronary intervention (PCI) of chronic total occlusions (CTOs) has been associated with significant clinical benefits, but remains technically demanding. Failure to cross the CTO with a guidewire is the most common cause of CTO PCI failure. CTO crossing can be achieved in the antegrade or retrograde direction and can be accomplished by maintaining true lumen position throughout or via subintimal dissection/reentry techniques. A procedural plan should be created prior to the procedure through careful angiographic review of four key parameters: (a) morphology of the proximal occlusion cap; (b) length of the occlusion; (c) quality of the distal vessel and presence of bifurcation at the distal cap; and (d) suitability of collateral circulation for retrograde crossing. Dual coronary injection is recommended in all cases with contralateral collaterals for detailed characterization of the lesion. If one approach fails to progress, a quick transition to the next approach is encouraged to maximize efficacy and efficiency. Procedural complications, including vessel perforation, may occur more frequently in CTO as compared with non-CTO PCI; hence, availability of necessary equipment and expertise in treating such complications are essential.