A Percutaneous Treatment Algorithm for Crossing Coronary Chronic Total Occlusions

Retrograde Coronary Chronic Total Occlusion Intervention (JR-CTO) Score: From the Japanese CTO-PCI Expert Registry

BACKGROUND

Despite the effectiveness of the retrograde approach for chronic total occlusion (CTO) lesions, there are no standardized tools to predict the success of retrograde percutaneous coronary intervention (PCI).

OBJECTIVES

The aim of this study was to develop a prediction tool to identify CTO lesions that will achieve successful retrograde PCI.

METHODS

This study evaluated data from 2,374 patients who underwent primary retrograde CTO-PCI and were enrolled in the Japanese CTO-PCI Expert Registry between January 2016 and December 2022 (NCT01889459). All observations were randomly assigned to the derivation and validation cohorts at a 2:1 ratio. The prediction score for guidewire failure in retrograde CTO-PCI was determined by assigning 1 point for each factor and summing all accrued points.

RESULTS

The JR-CTO score (moderate-severe calcification, tortuosity, Werner collateral connection grade ≤1, and nonseptal collateral channel) demonstrated a C-statistic for guidewire failure of 0.72 (95% CI: 0.67-0.76) and 0.71 (95% CI: 0.64-0.77) in the derivation and validation cohorts, respectively. Patients with lower scores had higher guidewire and technical success rates and decreased guidewire crossing time and procedural time (P < 0.01).

CONCLUSIONS

The JR-CTO (Japanese Retrograde Chronic Total Occlusion) score, a simple 4-item score that predicts successful guidewire crossing in patients undergoing retrograde CTO-PCI, has the potential to support clinical decision-making for the retrograde approach.

Chronic Total Occlusions: A State-of-the-Art Review

The percutaneous management of chronic total occlusions (CTO) is a well-established sub-specialty of Interventional Cardiology, requiring specialist equipment, training, and techniques. The heterogeneity of approaches in CTO has led to the generation of multiple algorithms to guide operators in their management. The evidence base for management of CTOs has suffered from inconsistent descriptive and quantitative terminology in defining the nature of lesions and techniques utilised, as well as seemingly contradictory data about improvement in ventricular function, symptoms of angina, and mortality from large-scale registries and randomised controlled trials. Through this review, we explore the history of CTO management and its supporting evidence in detail, with an outline of limitations of CTO-percutaneous coronary intervention and a look at the future of this growing field within cardiology.

Same-day discharge after large-bore access in percutaneous coronary intervention of chronic total coronary occlusions

BACKGROUND

Same-day discharge (SDD) in patients undergoing percutaneous coronary intervention (PCI) of a chronic total occlusion (CTO) is appealing because of the increased patient comfort. However, data on SDD following large-bore vascular access are scarce.

AIMS

We investigated the feasibility and safety of SDD in patients undergoing large-bore CTO PCI.

METHODS

Between 2013 and 2023, 948 patients were prospectively enrolled in a single-centre CTO registry and underwent CTO PCI. SDD was pursued in all patients. Large-bore access was defined as the use of ≥7 French (Fr) sheaths in ≥1 access site. A logistic regression analysis was used to identify predictors for non-SDD. Clinical follow-up was obtained at 30 days.

RESULTS

SDD was observed in 62% of patients. Large-bore access was applied in 99% of the cohort. SDD patients were younger and more often male, with lower rates of renal insufficiency and prior coronary artery bypass grafting. Local access site bleeding (odds ratio [OR] 8.53, 95% confidence interval [CI]: 5.24-13.87) and vascular access complications (OR 7.23, 95% CI: 1.98-26.32) made hospitalisation more likely, with vascular access complications occurring in 3%. At 30 days, the hospital readmission rate was low in both SDD and non-SDD patients (5% vs 7%; p=non-significant). Finally, SDD was not a predictor for major adverse cardiovascular events (MACE) at follow-up.

CONCLUSIONS

Same-day discharge can be achieved in the majority of patients undergoing CTO PCI with large-bore (≥7 Fr) access. Similar low hospital readmission and MACE rates between SDD and non-SDD patients at 30 days demonstrate the feasibility and safety of SDD.

Procedural Results and Long-term Outcome of Chronic Total Occlusion Percutaneous Coronary Intervention in a UK Non-surgical Centre

Background

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has evolved a great deal over recent years, with increased procedural success and lower complication rates being reported. This study aims to evaluate the feasibility, safety and success of a dedicated CTO programme in a large UK PCI centre without on-site cardiothoracic surgery facilities.

Methods

Clinical and procedural data were retrospectively collected for consecutive unselected patients undergoing CTO PCI between 2015 and 2019 from the local database and regional electronic patient records. In-hospital outcomes and long-term major adverse cardiovascular events (all-cause mortality, MI, stroke and target vessel revascularisation) were recorded.

Results

A total of 170 patients underwent 191 CTO procedures during the study period. The mean age was 63 ± 10 years and 80.6% of patients were male (n=137). The clinical indications were: stable chronic coronary syndromes in 88.5% (n=169) of patients; staged procedures in the context of acute coronary syndromes in 1.6% (n=3); and presentation with acute coronary syndrome in 9.9% (n=19). The procedural success rate was 50.0% (n=25) for general interventional cardiologists and 90.1% (n=127) for dedicated CTO operators. In-hospital major adverse cardiovascular events occurred once (0.5%) and interhospital transfer for emergency salvage cardiac surgery was not required. Long-term follow-up data at a median duration of 3.8 years revealed 4 (2.4%) cardiac deaths, 14 (8.3%) spontaneous MI events and 10 (5.9%) target vessel revascularisations.

Conclusion

These data suggest CTO PCI using contemporary techniques is both safe and effective when undertaken in a high-volume non-surgical centre by experienced operators.

Validation of the BCIS CHIP Score in chronic total occlusion percutaneous coronary intervention

BACKGROUND

The complex high-risk indicated percutaneous coronary intervention (CHIP) score is a tool developed using the British Cardiovascular Intervention Society (BCIS) database to define CHIP cases and predict in-hospital major adverse cardiac or cerebrovascular events (MACCE).

AIM

To assess the validity of the CHIP score in chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

METHODS

We evaluated the performance of the CHIP score on 8341 CTO PCIs from the Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS-CTO) performed at 44 centers between 2012 and 2023.

RESULTS

In our cohort, 7.8% (n = 647) of patients had a CHIP score of 0, 50.2% (n = 4192) had a CHIP score of 1-2, 26.2% (n = 2187) had a CHIP score of 3-4, 11.7% (n = 972) had a CHIP score of 5-6, 3.3% (n = 276) had a CHIP score of 7-8, and 0.8% (n = 67) had a CHIP score of 9+. The incidence of MACCE for a CHIP score of 0 was 0.6%, reaching as high as 8.7% for a CHIP score of 9+, confirming that a higher CHIP score is associated with a higher risk of MACCE. The estimated increase in the risk of MACCE per one score unit increase was 100% (95% confidence interval [CI]: 65%-141%). The AUC of the CHIP score model for predicting MACCE in our cohort was 0.63 (95% CI: 0.58-0.67). There was a positive correlation between the CHIP score and the PROGRESS-CTO MACE score (Spearman's correlation: 0.37; 95% CI: 0.35-0.39; p < 0.001).

CONCLUSIONS

The CHIP score has modest predictive capacity for MACCE in CTO PCI.

Impact of sex on myocardial perfusion following percutaneous coronary intervention of chronic total coronary occlusions

OBJECTIVES

We sought to investigate the impact of sex on myocardial perfusion changes following chronic total coronary occlusion (CTO) percutaneous coronary intervention (PCI) as measured by [15O]H2O positron-emission tomography (PET) perfusion imaging.

BACKGROUND

CTO PCI has been associated with an increase in myocardial perfusion, yet females are less likely to undergo revascularization. As such, data on the impact of sex on myocardial perfusion following CTO PCI is scarce.

METHODS

A total of 212 patients were prospectively enrolled and underwent CTO PCI combined with [15O]H2O PET perfusion imaging prior to and 3 months after PCI. Hyperemic myocardial blood flow (hMBF, mL·min-1·g-1) and coronary flow reserve (CFR) allocated to the CTO territory were quantitatively assessed.

RESULTS

This study comprised 34 (16 %) females and 178 (84 %) males. HMBF at baseline did not differ between sexes. Females showed a higher increase in hMBF than males (Δ1.34 ± 0.67 vs. Δ1.06 ± 0.74, p = 0.044), whereas post-PCI hMBF was comparable (2.59 ± 0.85 in females vs. 2.28 ± 0.84 in males, p = 0.052). Female sex was independently associated with a higher increase in hMBF after correction for clinical covariates. CFR increase after revascularization was similar in females and males (Δ1.47 ± 0.99 vs. Δ1.30 ± 1.14, p = 0.711).

CONCLUSIONS

The present study demonstrates a greater recovery of stress perfusion in females compared to males as measured by serial [15O]H2O PET imaging. In addition, a comparable increase in CFR was found in females and males. These results emphasize the benefit of performing CTO PCI in both sexes.

CLINICAL PERSPECTIVE

What is new? What are the clinical implications?

Practice differences and knowledge gaps in complex and high-risk interventions between Japan and the USA: A case-based discussion

Advances in percutaneous coronary intervention (PCI) devices and techniques have expanded the pool of eligible patients for revascularization, including those with comorbidities, reduced left ventricular function, or anatomical complexity (defined as CHIP: complex and high-risk interventions in indicated patients). CHIP interventions are typically performed by selected operators who specialize in complex PCI. This review presents two cases performed in the USA, to discuss the similarities and differences in practice patterns between CHIP operators in Japan and the USA. The first case involves a 58-year-old male presenting with myocardial infarction and cardiogenic shock, and the second case involves a 51-year-old female with a history of coronary artery bypass grafting presenting with a chronic total occlusion and PCI complicated by vessel perforation. The discussion focuses on appropriate patient selection, the role of the heart team approach for decision-making, the use of hemodynamic support devices, and other relevant factors. By comparing practices in Japan and the USA, this review highlights opportunities for knowledge exchange and potential areas for improving patient outcomes.

Clinical outcomes of percutaneous coronary intervention in chronic total occlusion in patients with type 2 diabetes mellitus

INTRODUCTION AND OBJECTIVES

Coronary chronic total occlusions (CTOs) are relatively common findings in patients with type 2 diabetes mellitus (T2DM). However, the indication for percutaneous coronary intervention (PCI) and its clinical benefit in these patients remain controversial.

METHODS

A single-center retrospective cohort study with prospectively collected outcomes was carried out with CTO patients undergoing PCI in 2019 and 2020. Patients were divided into two groups according to previous T2DM diagnosis (T2DM and non-T2DM). The primary outcome was recurrence of angina and/or heart failure symptoms and secondary outcomes were myocardial infarction and all-cause mortality.

RESULTS

A total of 177 patients (82.5% male) were included in the analysis, with a mean age of 65±11 years. The primary outcome (total symptom recurrence) occurred in 16.6% of the sample, with no difference between groups (non-T2DM 13.6% vs. T2DM 21.2%, p=0.194) in a two-year follow-up. Angina recurrence was significantly more frequent in T2DM patients (15.2%, p=0.043). The presence of T2DM was not an independent predictor of symptom recurrence (p=0.429, HR 1.37, 95% CI 0.62-2.98). Myocardial infarction and all-cause mortality were also not different between groups (T2DM 1.5%, p=0.786 and 4.5%, p=0.352, respectively, on survival analysis). Independent predictors of all-cause mortality were left ventricular function and creatine clearance (p=0.039, HR 0.92, 95% CI 0.85-0.99 and p=0.013, HR 0.96, 95% CI 0.93-0.99, respectively).

CONCLUSIONS

T2DM did not influence outcomes in CTO patients undergoing PCI, and its presence should not be a limiting factor in deciding on CTO revascularization.

High-density zwitterionic polymer brushes exhibit robust lubrication properties and high antithrombotic efficacy in blood-contacting medical devices

High-performance catheters are essential for interventional surgeries, requiring reliable anti-adhesive and lubricated surfaces. This article develops a strategy for constructing high-density sulfobetaine zwitterionic polymer brushes on the surface of catheters, utilizing dopamine and sodium alginate as the primary intermediate layers, where dopamine provides mussel-protein-like adhesion to anchor the polymer brushes to the catheter surface. Hydroxyl-rich sodium alginate increases the number of grafting sites and improves the grafting mass by more than 4 times. The developed high-density zwitterionic polymer brushes achieve long-lasting and effective lubricity (μ<0.0078) and are implanted in rabbits for four hours without bio-adhesion and thrombosis in the absence of anticoagulants such as heparin. Experiments and molecular dynamics simulations demonstrate that graft mass plays a decisive role in the lubricity and anti-adhesion of polymer brushes, and it is proposed to predict the anti-adhesion of polymer brushes by their lubricity to avoid costly and time-consuming bioassays during the development of amphoteric polymer brushes. A quantitative influence of hydration in the anti-adhesion properties of amphiphilic polymer brushes is also revealed. Thus, this study provides a new approach to safe, long-lasting lubrication and anticoagulant surface modification for medical devices in contact with blood. STATEMENT OF SIGNIFICANCE: High friction and bioadhesion on medical device surfaces can pose a significant risk to patients. In response, we have developed a safer, simpler, and more application-specific surface modification strategy that addresses both the lubrication and anti-bioadhesion needs of medical device surfaces. We used dopamine and sodium alginate as intermediate layers to drastically increase the grafting density of the zwitterionic brushes and enabled the modified surfaces to have an extremely low coefficient of friction (μ = 0.0078) and to remain non-bioadhesive for 4 hours in vivo. Furthermore, we used molecular dynamics simulations to gain insight into the mechanisms behind the superior anti-adhesion properties of the high-density polymer brushes. Our work contributes to the development and application of surface-modified coatings.

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

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

Value of different CTO scoring systems in predicting procedural success in coronary chronic total occlusion intervention in Egyptian patients

BACKGROUND

Chronic total occlusion (CTO) lesions in coronary arteries pose a significant challenge for coronary interventionists, often leading to referrals for coronary artery bypass graft surgery (CABG). Successful percutaneous coronary intervention (PCI) for CTOs requires accurate assessment of procedural potential. This study, comprising 100 Egyptian patients aged 37-81, compares the predictive efficacy of various CTO scoring systems in PCI success determination. Patients with CTO in at least one coronary artery, planned for elective PCI based on objective evidence of ischemia, were included. Experienced operators performed PCI, recording procedural variables, and assessing complications. Logistic regression analysis revealed an inverse linear relationship between success rates and score values across all systems.

RESULTS

Although, the predictive capacity of the scores was similar, with slight differences. The Euro CTO (CASTLE) score10 exhibited superior predictive efficacy, followed by the CL score9, while PROGRESS8 and J-CTO7 scores showed lower significance. ORA CTO11 score demonstrated intermediate predictive ability, and PROGRESS score8 had the least predictive value.

CONCLUSION

The CASTLE score10 proved most effective in predicting PCI success for CTO cases in Egyptian patients, with operators advised to choose scoring systems based on experience and case characteristics. Proper planning remains crucial for optimizing success rates in CTO PCI procedures, irrespective of the scoring system employed.

Clinical results of percutaneous coronary intervention in chronic total occlusions of the right coronary artery

INTRODUCTION AND OBJECTIVES

Coronary chronic total occlusions (CTOs) of the right coronary artery (RCA) are a relatively common finding in the context of coronary angiography. However, the benefit of revascularization remains controversial.

METHODS

A single-center retrospective cohort analysis prospectively collected outcomes of CTO patients undergoing percutaneous coronary intervention (PCI) in 2019 and 2020. Patients were divided into two groups according to the CTO vessel treated (left coronary artery [LCA]-CTO or RCA-CTO). The primary outcome was defined as the recurrence of angina and/or heart failure (HF) symptoms and secondary outcomes were myocardial infarction (MI) and all-cause mortality.

RESULTS

A total of 177 patients (82.5% male) were included in the analysis, with a mean age of 65±11 years. The primary outcome occurred in 28 (16.6%) patients and was significantly more frequent in RCA-CTO patients (19, 24.7%, p=0.010) in a mean follow-up of 18 months. This was mainly driven by recurrence of HF symptoms (12, 15.6%, p=0.013). Treated RCA-CTO was an independent predictor of the primary outcome (p=0.019, HR 2.66, 95% CI 1.17-6.05). MI and mortality rates were no different between groups (RCA-CTO with 1.3%, p=0.361 and 2.6%, p=0.673, respectively, on survival analysis). Left ventricular ejection fraction was an independent predictor of mortality (p=0.041, HR 0.93, 95% CI 0.87-0.99).

CONCLUSIONS

Revascularization of CTO lesions by PCI was associated with low rates of symptom recurrence, and clinical outcomes showed no differences regardless of which artery was treated. Recanalization of RCA-CTO was less beneficial in reducing the recurrence of HF symptoms.

Performance of the minimalistic hybrid approach algorithm versus other conventional algorithms in the percutaneous treatment of chronic total occlusions

BACKGROUND

The "Minimalistic Hybrid Approach" (MHA) has been proposed to reduce the invasiveness of chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

AIMS

This study aims to assess whether MHA may also reduce the utilization of PCI resources (devices, radiations, and contrast) by comparing it with other conventional algorithms.

METHODS

We aimed to assess the impact of MHA on device, radiation, and contrast usage during CTO-PCI analyzing data from the Belgian Working Group on CTO (BWG-CTO) registry. Patients were divided, depending on the algorithm used, into two groups: Conventional versus Minimalistic. Primary objectives were procedure performance measures such as device usage (microcatheters and guidewires), radiological parameters, and contrast use. At 1-year follow-up, patients were evaluated for target vessel failure (TVF), defined as a composite of cardiac death, new myocardial infarction, and target vessel revascularization.

RESULTS

Overall, we analyzed 821 CTO-PCIs (Conventional n = 650, Minimalistic n = 171). The Minimalistic group demonstrated higher complexity of CTO lesions. After adjusting for propensity score, the Minimalistic group had a significantly lower number of microcatheters used (1.49 ± 0.85 vs. 1.24 ± 0.64, p = 0.026), while the number of guidewires was comparable (4.80 ± 3.29 vs. 4.35 ± 2.94, p = 0.30). Both groups had similar rates of success and procedural complications, as well as comparable procedural and fluoroscopic times and contrast volume used. At the 1-year follow-up, both groups showed comparable rates of TVF (hazard ratio: 0.57; 95% confidence interval: 0.24-1.34, p = 0.195).

CONCLUSION

The MHA may slightly reduce the number of dedicated devices used during CTO-PCI, without adversely affecting the procedural success or long-term outcome.

Presence and Relevance of Myocardial Bridge in LAD-PCI of CTO and Non-CTO Lesions

BACKGROUND

Intravascular ultrasound (IVUS) studies show that one-quarter of left anterior descending (LAD) arteries have a myocardial bridge. An MB may be associated with stent failure when the stent extends into the MB.

OBJECTIVES

The aim of this study was to investigate: 1) the association between an MB and chronic total occlusion (CTO) in any LAD lesions; and 2) the association between an MB and subsequent clinical outcomes after percutaneous coronary intervention in LAD CTOs.

METHODS

A total of 3,342 LAD lesions with IVUS-guided percutaneous coronary intervention (280 CTO and 3,062 non-CTO lesions) were included. The primary outcome was target lesion failure (cardiac death, target vessel myocardial infarction, definite stent thrombosis, and ischemic-driven target lesion revascularization).

RESULTS

An MB by IVUS was significantly more prevalent in LAD CTOs than LAD non-CTOs (40.4% [113/280] vs 25.8% [789/3,062]; P < 0.0001). The discrepancy in CTO length between angiography and IVUS was greater in 113 LAD CTOs with an MB than 167 LAD CTOs without an MB (6.0 [Q1, Q3: 0.1, 12.2] mm vs 0.2 [Q1, Q3: -1.4, 8.4] mm; P < 0.0001). Overall, 48.7% (55/113) of LAD CTOs had a stent that extended into an MB after which target lesion failure was significantly higher compared to a stent that did not extend into an MB (26.3% vs 0%; P = 0.0004) or compared to an LAD CTO without an MB (26.3% vs 9.6%; P = 0.02).

CONCLUSIONS

An MB was more common in LAD CTO than non-CTO LAD lesions. If present, approximately one-half of LAD CTOs had a stent extending into an MB that, in turn, was associated with worse outcomes.

Design, preparation, and characterization of lubricating polymer brushes for biomedical applications

The lubrication modification of biomedical devices significantly enhances the functionality of implanted interventional medical devices, thereby providing additional benefits for patients. Polymer brush coating provides a convenient and efficient method for surface modification while ensuring the preservation of the substrate's original properties. The current research has focused on a "trial and error" method to finding polymer brushes with superior lubricity qualities, which is time-consuming and expensive, as obtaining effective and long-lasting lubricity properties for polymer brushes is difficult. This review summarizes recent research advances in the biomedical field in the design, material selection, preparation, and characterization of lubricating and antifouling polymer brushes, which follow the polymer brush development process. This review begins by examining various approaches to polymer brush design, including molecular dynamics simulation and machine learning, from the fundamentals of polymer brush lubrication. Recent advancements in polymer brush design are then synthesized and potential avenues for future research are explored. Emphasis is placed on the burgeoning field of zwitterionic polymer brushes, and highlighting the broad prospects of supramolecular polymer brushes based on host-guest interactions in the field of self-repairing polymer brush applications. The review culminates by providing a summary of methodologies for characterizing the structural and functional attributes of polymer brushes. It is believed that a development approach for polymer brushes based on "design-material selection-preparation-characterization" can be created, easing the challenge of creating polymer brushes with high-performance lubricating qualities and enabling the on-demand creation of coatings. STATEMENT OF SIGNIFICANCE: Biomedical devices have severe lubrication modification needs, and surface lubrication modification by polymer brush coating is currently the most promising means. However, the design and preparation of polymer brushes often involves "iterative testing" to find polymer brushes with excellent lubrication properties, which is both time-consuming and expensive. This review proposes a polymer brush development process based on the "design-material selection-preparation-characterization" strategy and summarizes recent research advances and trends in the design, material selection, preparation, and characterization of polymer brushes. This review will help polymer brush researchers by alleviating the challenges of creating polymer brushes with high-performance lubricity and promises to enable the on-demand construction of polymer brush lubrication coatings.

Prevalence of Collateral Typology in Coronary Chronic Total Occlusion and Its Impact on Percutaneous Intervention Performance

The presence of collateral channels providing distal blood supply is a distinctive characteristic of chronic total occlusion (CTO) lesions. However, data about the distinct baseline and procedural characteristics of each collateral subset are scarce. Accordingly, we sought to explore the procedural aspects specific for each collateral typology (ipsilateral collaterals [ICs], contralateral collaterals [CCs] or mixed) in CTO-percutaneous coronary intervention (PCI). A retrospective analysis of our CTO-PCI registry was performed to investigate the prevalence, procedural characteristics, and outcomes specific for each CTO-PCI subset, defined according to the inter-arterial connection anatomy. A total of 209 cases were included. Of the included cases, 45 (22%) and 92 (44%) patients displayed solely IC or CC, respectively, whereas in 72 (34%) both IC and CC were present (mixed). The procedural success rate was high (91.1%) and comparable among the different groups, despite greater lesion complexity in the CC group. The most frequent target vessel was the left circumflex in the IC group (51% of cases) and the right coronary artery in the CC (63%) and mixed (57%) groups. Among the IC cases, 42% showed a poor collateral connection function (2% and 10% for the CC and mixed group, respectively), and 46% showed a suboptimal collateral recipient artery filling (21% and 20% for the CC and mixed group, respectively). Most of the IC cases were performed using a single access (96%). In conclusion, the success and complication rates were comparable among the collateral typology groups, irrespective of the differences in the baseline and procedural characteristics. Phenotyping CTO as hereby proposed might be helpful for targeted procedural considerations.

Computed Tomography Angiography-Derived Scores for Prediction of Chronic Total Occlusion Percutaneous Coronary Intervention Using the Hybrid Algorithm

Whereas coronary computed tomography angiography (CCTA) exceeds invasive angiography for predicting the procedural outcome of chronic total occlusion (CTO) percutaneous coronary intervention (PCI), CCTA-derived scores have never been validated in the hybrid CTO PCI population. In this single-center, retrospective, observational study, we included 108 consecutive patients with 110 CTO lesions and preprocedural CCTA who underwent hybrid CTO PCI to assess the diagnostic accuracy of CCTA-derived scoring systems. Successful guidewire crossing within 30 min was set as the primary endpoint. The secondary endpoints were final procedural success and the need for using any non-antegrade wiring (AW) strategy within the hybrid algorithm. Time-efficient guidewire crossing and final procedural success were achieved in 53.6% and 89.1% of lesions, respectively, while in 36.4% of the procedures, any non-AW strategy was applied. The median J-CTO score was 1 (interquartile range (IQR): 0, 2), while the CT-RECTOR, KCCT, J-CTOCCTA, and RECHARGECCTA scores were 2 (IQR: 1, 3), 3 (IQR: 2, 5), 1 (IQR: 0, 3), and 2 (IQR: 1, 3), respectively. All scores were significantly higher in the lesions with failed versus successful time-efficient guidewire crossing. Although all of the CCTA-derived scores had numerically higher predictive values than the angiographic J-CTO score, no significant differences were noted between the scores in any of the analyzed study endpoints. High sensitivity of the CT-RECTOR and RECHARGECCTA scores (both 89.8%) for predicting successful guidewire crossing within 30 min, and high sensitivity (90.8%) of the KCCT score for predicting final procedural success, were noted. CCTA-derived scoring systems are accurate, noninvasive tools for the prediction of the procedural outcome of hybrid CTO PCI, and may aid in identifying the need for use of the hybrid algorithm.

Chronic total occlusion rotational atherectomy (CTO RA) versus non-CTO RA in coronary artery disease: A meta-analysis of clinical outcomes and complications

Background

Chronic total occlusion rotational atherectomy (CTO RA) is an emerging intervention in coronary artery disease (CAD), although data comparing its outcomes and complications with non-CTO RA are scarce. We sought to evaluate the outcomes of RA in CTO lesions compared to those in non-CTO lesions by performing a meta-analysis.

Methods

We conducted a systematic review and meta-analysis of studies comparing the clinical outcomes and complications between CTO RA and non-CTO RA in patients with CAD. We searched PUBMED, CINAHL, EMBASE and Cochrane Central Register of Clinical Trials for any studies that compared the outcomes of RA in CTO and non-CTO lesions. The outcomes analyzed included in-hospital major adverse cardiovascular events (MACE), target vessel revascularization (TVR), angiographic success, procedural success, periprocedural complications, coronary perforation, and all-cause mortality.

Results

Four studies with a total of 1868 patients were included, spanning from 2018 to 2022, from Germany, Taiwan, and Korea. The median age of included patients was 71. The rate of the pooled results indicated a moderate, non-significant increase in in-hospital MACE and TVR for CTO RA compared to non-CTO RA. There was a small, non-significant decrease in angiographic and procedural success in CTO RA compared to non-CTO RA. CTO RA was associated with a non-significant increase in periprocedural complications and a significant increase in coronary perforation compared to non-CTO RA. All-cause mortality showed a non-significant increase in the CTO RA group.

Conclusion

This meta-analysis provides evidence that while CTO RA may be associated with a higher risk of coronary perforation, the risk of other outcomes including MACE, TVR, and all-cause mortality is not significantly different compared to non-CTO RA. More research is needed to further understand these relationships and to optimize treatment strategies in patients with CAD undergoing CTO RA.

Exploring indicators of success in chronic total occlusion percutaneous coronary intervention with Stingray system-based antegrade dissection re-entry: Insights from retrospective analysis

BACKGROUND

The predictors of success of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) through antegrade dissection and re-entry (ADR) using the Stingray system (Stingray ADR) remain elusive, mainly owing to the lack of consecutive angiographic and procedural records of patients.

OBJECTIVES

This study aimed to identify indicators that can determine the success of CTO PCI performed using the Stingray ADR technique.

METHODS

The clinical data of 115 patients who underwent CTO PCI through Stingray ADR at the same cardiac center were retrospectively and consecutively collected. Multivariate logistic regression analysis was performed to investigate the indicators of the success of ADR attempts.

RESULTS

The technical success rate of Stingray ADR in CTO PCI was 72.2%. The overall technical success rate of CTO recanalization was 78.3% in all CTO PCIs having used Stingray Low Profile balloon. Vessel calcification (odds ratio [OR]: 4.03; 95% confidence interval [CI]: 1.49-11.88; p = 0.008), and retrograde puncture indicator (OR: 4.89; 95% CI: 1.51-17.11; p = 0.009) were identified as independent positive predictors. Blunt/no stump proximal to the occlusion segment (OR: 0.22; 95% CI: 0.06-0.64; p = 0.009), decision time before Stingray ADR (per 1 h increase) (OR: 0.54; 95% CI: 0.31-0.92; p = 0.026), operation duration of Stingray ADR (per 10 min increase) (OR: 0.62; 95% CI: 0.40-0.94; p = 0.028), and puncture site at the intraplaque region (OR: 0.24; 95% CI: 0.06-0.84; p = 0.026) were identified as the four negative independent predictors.

CONCLUSIONS

This study revealed independent predictors of the success of CTO PCI performed using the Stingray ADR technique. As for CTO characteristics, the presence of calcification in the CTO segment and a tapered stump proximal to the lesion site can facilitate successful Stingray ADR. As for the procedures, the success rate of Stingray ADR can be improved by initiating the technique decisively and promptly, operating the system quickly and accurately and creating a puncture in the distal cap region of CTO under retrograde guidance.

The Retrograde Approach to Chronic Total Occlusion Percutaneous Coronary Interventions: Technical Analysis and Procedural Outcomes

BACKGROUND

Retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is associated with lower success and higher complication rates when compared with the antegrade approach.

OBJECTIVES

This study sought to assess contemporary techniques and outcomes of retrograde CTO PCI.

METHODS

We examined the baseline characteristics, procedural techniques and outcomes of 4,058 retrograde CTO PCIs performed at 44 centers between 2012 and 2023. Major adverse cardiac events (MACE) included any of the following in-hospital events: death, myocardial infarction, repeat target vessel revascularization, pericardiocentesis, cardiac surgery, and stroke.

RESULTS

The average J-CTO (Multicenter CTO Registry in Japan) score was 3.1 ± 1.1. Retrograde crossing was successful in 60.5% and lesion crossing in 81.6% of cases. The collaterals pathways successfully used were septals in 62.0%, saphenous vein grafts in 17.4%, and epicardials in 19.1%. The technical and procedural success rates were 78.7% and 76.6%, respectively. When retrograde crossing failed, technical success was achieved in 50.3% of cases using the antegrade approach. In-hospital MACE was 3.5%. The clinical coronary perforation rate was 5.8%. The incidence of in-hospital MACE with retrograde true lumen crossing, just marker antegrade crossing, conventional reverse controlled antegrade and retrograde tracking (CART), contemporary reverse CART, extended reverse CART, guide-extension reverse CART, and CART was 2.1%, 0.8%, 5.5%, 3.0%, 2.1%, 3.2%, and 4.1%, respectively; P = 0.01).

CONCLUSIONS

Retrograde CTO PCI is utilized in highly complex cases and yields moderate success rates with 5.8% perforation and 3.5% periprocedural MACE rates. Among retrograde crossing strategies, retrograde true lumen puncture was the safest. There is need for improvement of the efficacy and safety of retrograde CTO PCI.

Trends and Outcomes of Antegrade Dissection and Re-Entry in Chronic Total Occlusion Percutaneous Coronary Intervention

BACKGROUND

The contemporary frequency and outcomes of antegrade dissection and re-entry (ADR) for chronic total occlusion (CTO) percutaneous coronary intervention (PCI) have received limited study.

OBJECTIVES

The aim of this study was to determine the frequency and outcomes of ADR use in a large multicenter CTO PCI registry.

METHODS

The characteristics and outcomes of ADR were examined among 12,568 patients who underwent 12,841 CTO PCIs at 46 U.S. and non-U.S. centers between 2012 and 2023.

RESULTS

ADR was used in 2,385 of the procedures (18.6%). ADR use declined from 37.9% in 2012 to 14.5% in 2022 (P < 0.001). Patients in whom ADR was used had a high prevalence of comorbidities. Compared with cases that did not use ADR, ADR cases had more complex angiographic characteristics, higher mean J-CTO (Multicenter CTO Registry in Japan) score (2.94 ± 1.11 vs 2.23 ± 1.26; P < 0.001), lower technical success (77.0% vs 89.3%; P < 0.001), and higher in-hospital major adverse cardiac events (3.7% vs 1.6%; P < 0.001). The use of the CrossBoss declined from 71% in 2012 to 1.4% in 2022 and was associated with higher technical success (87%) compared with wire-based techniques (73%). The Stingray device displayed higher technical success (86%) compared with subintimal tracking and re-entry (STAR) (74%) and limited antegrade subintimal tracking (78%); however, its use has been decreasing, with STAR becoming the most used re-entry technique in 2022 (44% STAR vs 38% Stingray).

CONCLUSIONS

The use of ADR has been decreasing. ADR was used in more complex lesions and was associated with lower technical success and higher major adverse cardiac events compared with non-ADR cases. There has been a decrease in Stingray use and an increase in the use of STAR for re-entry.

Collateral grading systems in retrograde percutaneous coronary intervention of chronic total occlusions

BACKGROUND

The Japanese Channel (J-Channel) score was introduced to aid in retrograde percutaneous coronary intervention (PCI) of chronic total coronary occlusions (CTOs). The predictive value of the J-Channel score has not been compared with established collateral grading systems such as the Rentrop classification and Werner grade.

AIMS

To investigate the predictive value of the J-Channel score, Rentrop classification and Werner grade for successful collateral channel (CC) guidewire crossing and technical CTO PCI success.

METHODS

A total of 600 prospectively recruited patients underwent CTO PCI. All grading systems were assessed under dual catheter injection. CC guidewire crossing was considered successful if the guidewire reached the distal segment of the CTO vessel through a retrograde approach. Technical CTO PCI success was defined as thrombolysis in myocardial infarction flow grade 3 and residual stenosis <30%.

RESULTS

Of 600 patients, 257 (43%) underwent CTO PCI through a retrograde approach. Successful CC guidewire crossing was achieved in 208 (81%) patients. The predictive value of the J-Channel score for CC guidewire crossing (area under curve 0.743) was comparable with the Rentrop classification (0.699, p = 0.094) and superior to the Werner grade (0.663, p = 0.002). Technical CTO PCI success was reported in 232 (90%) patients. The Rentrop classification exhibited a numerically higher discriminatory ability (0.676) compared to the J-Channel score (0.664) and Werner grade (0.589).

CONCLUSIONS

The J-channel score might aid in strategic collateral channel selection during retrograde CTO PCI. However, the J-Channel score, Rentrop classification, and Werner grade have limited value in predicting technical CTO PCI success.

Deep Learning-based Prediction of Percutaneous Recanalization in Chronic Total Occlusion Using Coronary CT Angiography

Background CT is helpful in guiding the revascularization of chronic total occlusion (CTO), but manual prediction scores of percutaneous coronary intervention (PCI) success have challenges. Deep learning (DL) is expected to predict success of PCI for CTO lesions more efficiently. Purpose To develop a DL model to predict guidewire crossing and PCI outcomes for CTO using coronary CT angiography (CCTA) and evaluate its performance compared with manual prediction scores.

MATERIALS AND METHODS

Participants with CTO lesions were prospectively identified from one tertiary hospital between January 2018 and December 2021 as the training set to develop the DL prediction model for PCI of CTO, with fivefold cross validation. The algorithm was tested using an external test set prospectively enrolled from three tertiary hospitals between January 2021 and June 2022 with the same eligibility criteria. All participants underwent preprocedural CCTA within 1 month before PCI. The end points were guidewire crossing within 30 minutes and PCI success of CTO.

Results A total of 534 participants (mean age, 57.7 years ± 10.8 [SD]; 417 [78.1%] men) with 565 CTO lesions were included. In the external test set (186 participants with 189 CTOs), the DL model saved 85.0% of the reconstruction and analysis time of manual scores (mean, 73.7 seconds vs 418.2-466.9 seconds) and had higher accuracy than manual scores in predicting guidewire crossing within 30 minutes (DL, 91.0%; CT Registry of Chronic Total Occlusion Revascularization, 61.9%; Korean Multicenter CTO CT Registry [KCCT], 68.3%; CCTA-derived Multicenter CTO Registry of Japan (J-CTO), 68.8%; P < .05) and PCI success (DL, 93.7%; KCCT, 74.6%; J-CTO, 75.1%; P < .05). For DL, the area under the receiver operating characteristic curve was 0.97 (95% CI: 0.89, 0.99) for the training test set and 0.96 (95% CI: 0.90, 0.98) for the external test set. Conclusion The DL prediction model accurately predicted the percutaneous recanalization outcomes of CTO lesions and increased the efficiency of noninvasively grading the difficulty of PCI. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Pundziute-do Prado in this issue.

STAR procedure becomes SAFER: First-in-man case series of a new antegrade dissection re-entry technique

INTRODUCTION

Antegrade dissection and re-entry (ADR) is an integral part of the hybrid algorithm, which has allowed for improved outcomes in chronic total occlusion (CTO) coronary intervention (PCI).

METHODS

A new ADR method, Subintimal Antegrade FEnestration and Re-entry (SAFER), is described. The results of a first-in-man series are presented.

RESULTS

SAFER was performed on seven consecutive patients with angiographic and clinical success in all patients.

CONCLUSIONS

This first-in-man study has shown that the SAFER technique is feasible and effective with the possibility of improving the antegrade PCI CTO success rate.

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.

A Novel Parallel Wire-based Antegrade Dissection Re-entry Technique for Failed Retrograde Attempt of Coronary Chronic Total Occlusions with Risk Nomogram Analysis

BACKGROUND

Rapid development in coronary chronic total occlusion (CTO) interventional techniques and devices have achieved a greater success rate with favorable outcomes. Antegrade dissection re-entry (ADR) technique is an important CTO crossing strategy and a desirable approach for long CTOs with good distal landing zone. However, unsuccessful procedures in contemporary CTO-percutaneous coronary intervention (PCI) remain, especially in lesions with non-interventional collaterals.

METHOD

Based on a single center experience, a hybrid interventional algorithm, parallel wire-based ADR (PW-ADR) combines the advantages of parallel wire technique (PWT) and device-based ADR to target CTO lesions with failed retrograde approach. A retrospective analysis of patients who underwent PW-ADR was performed. A risk nomogram was created to identify patients at high risk for technical failure.

RESULTS

A total of 57 patients treated with PW-ADR were ultimately included in the present study. A total of 46 (80.7%) cases achieved technical success and procedural success, with low incidence of in-hospital complications or 1-year major adverse cardiac events (MACE). The risk nomogram identified 3 predictor variables associated with technical failure of PW-ADR, including tortuous vessel, J-CTO score, and times of antegrade coronary angiography (CAG) during ADR, with promising accuracy (AUROC 0.947).

CONCLUSION

The novel hybrid CTO-PCI algorithm, PW-ADR, provided an alternative interventional approach for complex CTO lesions with a promising success rate. The risk nomogram served as a prompter for high-risk cases, which may warrant a change in treatment strategy.

PCI for Flush Occluded Right Coronary Artery: Challenges and Techniques for Success

A 74-year-old man with prior coronary artery bypass surgery had a failing vein graft to the right coronary artery (RCA). He underwent retrograde chronic total occlusion recanalization of an ostial flush-occluded RCA facilitated by retrograde angioplasty at the aorto-ostial junction after failed retrograde electrocautery. The graft was then sacrificed. (Level of Difficulty: Advanced.).

Vascular Access in Percutaneous Coronary Intervention of Chronic Total Occlusions: A State-of-the-Art Review

The outcomes of chronic total occlusion percutaneous coronary intervention have considerably improved during the last decade with continued emphasis on improving procedural safety. Vascular access site bleeding remains one of the most frequent complications. Several procedural strategies have been implemented to reduce the rate of vascular access site complications. This state-of-the-art review summarizes and describes the current evidence on optimal vascular access strategies for chronic total occlusion percutaneous coronary intervention.

The importance of the "safety coronary guidewire" in the donor vessel during Chronic total occlusion percutaneous coronary intervention

Donor vessel injury is a well-known complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Due to significant amount of myocardium at risk, donor vessel injury may lead to rapid hemodynamic collapse. In this setting, prompt restoration of blood flow into the donor artery is of paramount importance. Advancement of a safety coronary workhorse guidewire in the donor vessel prior to attempting CTO PCI is a simple maneuver that provides access to the donor artery for rapid coronary intervention and restoration of blood flow, in the event of donor vessel injury. We describe two cases of CTO PCI that illustrate the value of the safety coronary guidewire.

A Chinese scoring system for predicting successful retrograde collateral traverse in patients with chronic total coronary occlusion

BACKGROUND

Retrograde approach technique has been challenging in percutaneous coronary interventional treatment of chronic total occlusion (CTO) coronary disease. The present study endeavors to determine a novel Chinese scoring system for predicting successful collateral channels traverse via retrograde approach.

METHODS

The demographic characteristics and angiographic characteristics of 309 CTO patient were analyzed by univariable and multivariable analysis for selecting potential predictors. And the nomogram was used to establish the scoring system. Then it was evaluated by the internal and external validation.

RESULTS

The predictors of Age, Connections between collateral channels and recipient vessels, and Channel Tortuosity (ACT) were identified with univariable and multivariable analysis and employed to the ACT score system. With acceptable calibrations, the area under curve of the scoring system and the external validation were 0.826 and 0.816 respectively. Based on score, the predictors were divided into three risk categories and it showed a consistent prediction power in the validation cohort.

CONCLUSIONS

The novel Chinese ACT score is a reliable tool for predicting successful retrograde collateral traverse.

Ultrathin Strut Biodegradable Polymer-Coated Sirolimus-Eluting Coronary Stents: Patient-Level Pooled Analysis From Two Indian Registries

Background Despite significant evolution in stent technology, female gender, and patients with diabetes mellitus, multivessel disease, total occlusions, long lesions, and small vessels represent the "Achilles' heel" of contemporary percutaneous coronary intervention (PCI). We performed a pooled analysis of high-risk subgroup on patient-level data from the T-Flex registry (1,203 patients) and a real-world Indian registry (1,269 patients), with the aim of assessing one-year safety and clinical performance of ultrathin strut biodegradable polymer-coated Supra family of sirolimus-eluting stents (SES) (Sahajanand Medical Technologies Limited, Surat, India) in the real-world, all-comer population. Method We pooled the following high-risk subgroups data from two all-comer registries: female gender (n=678), diabetes mellitus (n=852), multivessel disease (n=406), total occlusions (n=420), long lesions (≥28 mm) (n=1241), and small vessels (≤2.5 mm) (n=726). Both the registries included patients with coronary artery disease who underwent implantation of at least one SES belonging to the Supra family of stents from May 2016 until March 2018, irrespective of lesion complexity and comorbidities. The primary endpoint was the inci-dence of target lesion failure (TLF), a composite of cardiac death, target vessel myocardial infarction, and clinically indicated target lesion revas-cularization by percutaneous or surgical methods up to one year. The safety endpoint was stent thrombosis.  Results According to prespecified high-risk subgroups, one-year rates of TLF and overall stent thrombosis, respectively, were as follows: female gender (4.9% and 0.6%), diabetes mellitus (6.9% and 1.0%), multivessel disease (6.4% and 0.8%), total occlusions (5.2% and 0.5%), long lesions (≥28 mm) (6.6% and 0.8%), and small vessels (≤2.5 mm) (6.1% and 1.3%). Conclusion This present pooled analysis demonstrated the one-year safety and clinical performance of ultrathin strut biodegradable polymer-coated Supra family of SES in a real-world, all-comer population, with considerably low rates of TLF and stent thrombosis.

Distal Target Vessel Quality and Outcomes of Chronic Total Occlusion Percutaneous Coronary Intervention

BACKGROUND

Distal vessel quality is a key parameter in the global chronic total occlusion (CTO) crossing algorithm.

OBJECTIVES

The study sought to evaluate the association of distal vessel quality with the outcomes of CTO percutaneous coronary intervention.

METHODS

We examined the clinical and angiographic characteristics and procedural outcomes of 10,028 CTO percutaneous coronary interventions performed at 39 U.S. and non-U.S. centers between 2012 and 2022. A poor-quality distal vessel was defined as <2 mm diameter or with significant diffuse atherosclerotic disease. In-hospital major adverse cardiac events (MACE) included death, myocardial infarction, urgent repeat target vessel revascularization, tamponade requiring pericardiocentesis or surgery, and stroke.

RESULTS

A total of 33% of all CTO lesions had poor-quality distal vessel. When compared with good-quality distal vessels, CTO lesions with a poor-quality distal vessel had higher J-CTO (Japanese chronic total occlusion) scores (2.7 ± 1.1 vs 2.2 ± 1.3; P < 0.01), lower technical (79.9% vs 86.9%; P < 0.01) and procedural (78.0% vs 86.8%; P < 0.01) success, and higher incidence of MACE (2.5% vs 1.7%; P < 0.01) and perforation (6.4% vs 3.7%; P < 0.01). A poor-quality distal vessel was independently associated with technical failure and MACE. Poor-quality distal vessels were associated with higher use of the retrograde approach (25.2% vs 14.9%; P < 0.01) and higher air kerma radiation dose (2.4 [IQR: 1.3-4.0] Gy vs 2.0 [IQR: 1.1-3.5] Gy; P < 0.01).

CONCLUSIONS

A poor-quality distal vessel in CTO lesions is associated with higher lesion complexity, higher need for retrograde crossing, lower technical and procedural success, higher incidence of MACE and coronary perforation, and higher radiation dose.

Contemporary issues of percutaneous coronary intervention in heavily calcified chronic total occlusions: an expert review from the European CTO Club

Severe calcification is frequent in coronary chronic total occlusions (CTO), and its presence has been associated with increased procedural complexity and poor long-term outcomes following percutaneous coronary intervention (PCI) in an already challenging anatomical setting. The diagnostic characterisation of heavily calcified CTOs using non-invasive and invasive imaging tools can lead to the application of different therapeutic options during CTO PCI, in order to achieve adequate lesion preparation and optimal stent implantation. In this expert review, the European Chronic Total Occlusion Club provides a contemporary, methodological approach, specifically addressing heavily calcified CTOs, suggesting an integration of evidence-based diagnostic methods to tailored, up-to-date percutaneous therapeutic options.

Percutaneous Coronary Intervention for Chronic Total Occlusion-Contemporary Approach and Future Directions

In the aging society, the issue of coronary chronic total occlusion (CTO) has become a challenge for invasive cardiologists. Despite the lack of clear indications in European and American guidelines, the rates of percutaneous coronary interventions (PCI) for CTO increased over the last years. Well-conducted randomized clinical trials (RCT) and large observational studies brought significant and substantial progress in many CTO blind spots. However, the results regarding the rationale behind revascularization and the long-term benefit of CTO are inconclusive. Knowing the uncertainties regarding PCI CTO, our work sought to sum up and provide a comprehensive review of the latest evidence on percutaneous recanalization of coronary artery chronic total occlusion.

Safety and Efficiency of Rotational Atherectomy in Chronic Total Coronary Occlusion-One-Year Clinical Outcomes of an Observational Registry

The study sought to assess the procedural success of rotational atherectomy (RA) in coronary chronic total occlusion (CTO) and to investigate the in-hospital and one-year outcomes following RA. From 2015 to 2019, patients undergoing percutaneous coronary intervention for CTO (CTO PCI) were retrospectively included into the hospital database. The primary endpoint was procedural success. Secondary endpoints were in-hospital and one-year major adverse cardiovascular and cerebral event (MACCE) rates. During the study period of 5 years, 2.789 patients underwent CTO PCI. Patients treated with RA (n = 193, 6.92%) had a significantly higher procedural success (93.26% vs. 85.10%, p = 0.0002) compared to those treated without RA (n = 2.596, 93.08%). Despite a significantly higher rate of pericardiocentesis (3.11% vs. 0.50%, p = 0.0013) in the RA group, the in-hospital and one-year MACCE rate was similar in both groups (4.15% vs. 2.77%, p = 0.2612; 18.65% vs. 16.72%, p = 0.485). In conclusion, RA is associated with higher procedural success for CTO PCI, but has higher risks for pericardial tamponade than CTO PCI without the need for RA. Nevertheless, in-hospital and one-year MACCE rates did not differ in-between both groups.

Contemporary Management Before Chronic Total Occlusion Percutaneous Coronary Interventions: Insights From the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program

BACKGROUND

Guidelines recommend maximal antianginal medical therapy before attempted coronary artery chronic total occlusion (CTO) percutaneous coronary intervention (PCI). The degree to which this occurs in contemporary practice is unknown. We aimed to characterize the frequency and variability of preprocedural use of antianginal therapy and stress testing within 3 months before PCI of CTO (CTO PCI) across a nationally integrated health care system.

METHODS

We identified patients who underwent attempted CTO PCI from January 2012 to September 2018 within the Veterans Affairs Healthcare System. Patients were categorized by management before CTO PCI: presence of ≥2 antianginals, stress testing, and ≥2 antianginals and stress testing within 3 months of PCI attempt. Multivariable logistic regression and inverse propensity weighting were used for adjustment before trimming, with median odds ratios calculated for variability estimates.

RESULTS

Among 4250 patients undergoing attempted CTO PCI, 40% received ≥2 antianginal medications and 24% underwent preprocedural stress testing. The odds of antianginal therapy with more than one medication before CTO PCI did not change over the years of the study (odds ratio [OR], 1.0 [95% CI, 0.97-1.04]), whereas the odds of undergoing preprocedural stress testing decreased (OR, 0.97 [95% CI, 0.93-0.99]), and the odds of antianginal therapy with ≥2 antianginals and stress testing did not change (OR, 0.98 [95% CI, 0.93-1.04]). Median odds ratios (MOR) showed substantial variability in antianginal therapy across hospital sites (MOR, 1.3 [95% CI, 1.26-1.42]) and operators (MOR, 1.35 [95% CI, 1.26-1.63]). Similarly, preprocedural stress testing varied significantly by site (MOR, 1.68 [95% CI, 1.58-1.81]) and operator (MOR, 1.80 [95% CI, 1.56-2.38]).

CONCLUSIONS

Just under half of patients received guideline-recommended management before CTO PCI, with significant site and operator variability. These findings suggest an opportunity to reduce variability in management before CTO PCI.

Deep Learning Segmentation and Reconstruction for CT of Chronic Total Coronary Occlusion

Background CT imaging of chronic total occlusion (CTO) is useful in guiding revascularization, but manual reconstruction and quantification are time consuming. Purpose To develop and validate a deep learning (DL) model for automated CTO reconstruction. Materials and Methods In this retrospective study, a DL model for automated CTO segmentation and reconstruction was developed using coronary CT angiography images from a training set of 6066 patients (582 with CTO, 5484 without CTO) and a validation set of 1962 patients (208 with CTO, 1754 without CTO). The algorithm was validated using an external test set of 211 patients with CTO. The consistency and measurement agreement of CTO quantification were compared between the DL model and the conventional manual protocol using the intraclass correlation coefficient, Cohen κ coefficient, and Bland-Altman plot. The predictive values of CT-derived Multicenter CTO Registry of Japan (J-CTO) score for revascularization success were evaluated. Results In the external test set, 211 patients (mean age, 66 years ± 11 [SD]; 164 men) with 240 CTO lesions were evaluated. Automated segmentation and reconstruction of CTOs by DL was successful in 95% of lesions (228 of 240) without manual editing and in 48% of lesions (116 of 240) with the conventional manual protocol (P < .001). The total postprocessing and measurement time was shorter for DL than for manual reconstruction (mean, 121 seconds ± 20 vs 456 seconds ± 68; P < .001). The quantitative and qualitative CTO parameters evaluated with the two methods showed excellent correlation (all correlation coefficients > 0.85, all P < .001) and minimal measurement difference. The predictive values of J-CTO score derived from DL and conventional manual quantification for procedure success showed no difference (area under the receiver operating characteristic curve, 0.76 [95% CI: 0.69, 0.82] and 0.76 [95% CI: 0.69, 0.82], respectively; P = .55). Conclusion When compared with manual reconstruction, the deep learning model considerably reduced postprocessing time for chronic total occlusion quantification and had excellent correlation and agreement in the anatomic assessment of occlusion features. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Loewe in this issue.

Percutaneous coronary intervention of native coronary artery versus saphenous vein graft in patients with prior coronary artery bypass graft surgery: Rationale and design of the multicenter, randomized PROCTOR trial

BACKGROUND

Patients with prior coronary artery bypass grafting (CABG) frequently require repeat percutaneous revascularization due to advanced age, progressive coronary artery disease and bypass graft failure. Percutaneous coronary intervention (PCI) of either the bypass graft or the native coronary artery may be performed. Randomized trials comparing native vessel PCI with bypass graft PCI are lacking and long-term outcomes have not been reported.

METHODS

PROCTOR (NCT03805048) is a prospective, multicenter, randomized controlled trial, that will include 584 patients presenting with saphenous vein graft (SVG) failure and a clinical indication for revascularization, as determined by the local Heart Team. The trial is designed to compare the clinical and angiographic outcomes in patients randomly allocated in a 1:1 fashion to either a strategy of native vessel PCI or SVG PCI. The primary study endpoint is a 3-year composite of major adverse cardiac events (MACE: all-cause mortality, non-fatal target coronary territory myocardial infarction [MI], or clinically driven target coronary territory revascularization). At 3-years, after evaluation of the primary endpoint, follow-up invasive coronary angiography will be performed. Secondary endpoints comprise individual components of MACE at 1, 3 and 5 years follow-up, PCI-related MI, MI >48 hours after index PCI, target vessel failure, target lesion revascularization, renal failure requiring renal-replacement therapy, angiographic outcomes at 3-years and quality of life (delta Seattle Angina Questionnaire, Canadian Cardiovascular Society Grading Scale and Rose Dyspnea Scale).

CONCLUSION

PROCTOR is the first randomized trial comparing an invasive strategy of native coronary artery PCI with SVG PCI in post-CABG patients presenting with SVG failure.

Health Status Outcomes in Older Adults Undergoing Chronic Total Occlusion Percutaneous Coronary Intervention

Background Although chronic total occlusions (CTOs) are common in older adults, they are less likely to be offered CTO percutaneous coronary intervention for angina relief than younger adults. The health status impact of CTO percutaneous coronary intervention in adults aged ≥75 years has not been studied. We sought to compare technical success rates and angina-related health status outcomes at 12 months between adults aged ≥75 and <75 years in the OPEN-CTO (Outcomes, Patient Health Status, and Efficiency in Chronic Total Occlusion) registry. Methods and Results Angina-related health status was assessed with the Seattle Angina Questionnaire (score range 0-100, higher scores denote less angina). Technical success rates were compared using hierarchical modified Poisson regression, and 12-month health status was compared using hierarchical multivariable linear regression between adults aged ≥75 and <75 years. Among 1000 participants, 19.8% were ≥75 years with a mean age of 79.5±4.1 years. Age ≥75 years was associated with a lower likelihood of technical success (adjusted risk ratio=0.92 [95% CI, 0.86-0.99; P=0.02]) and numerically higher rates of in-hospital major adverse cardiovascular events (9.1% versus 5.9%, P=0.10). There was no difference in Seattle Angina Questionnaire Summary Score at 12 months between adults aged ≥75 and <75 years (adjusted difference=0.9 [95% CI, -1.4 to 3.1; P=0.44]). Conclusions Despite modestly lower success rates and higher complication rates, adults aged ≥75 years experienced angina-related health status benefits after CTO-percutaneous coronary intervention that were similar in magnitude to adults aged <75 years. CTO percutaneous coronary intervention should not be withheld based on age alone in otherwise appropriate candidates.

Validation of the new PROGRESS-CTO complication risk scores in the OPEN-CTO registry

BACKGROUND

Risk stratification before chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is important to inform procedural planning as well as patients and their families. We sought to externally validate the PROGRESS-CTO complication risk scores in the OPEN-CTO registry.

METHODS

OPEN-CTO is a prospective registry of 1000 consecutive CTO PCIs performed at 12 experienced US centers using the hybrid algorithm. Endpoints of interest were in-hospital all-cause mortality, need for pericardiocentesis, acute myocardial infarction (MI), and major adverse cardiovascular events (MACE) (a composite of all-cause mortality, stroke, periprocedural MI, urgent repeat revascularization, and tamponade requiring pericardiocentesis). Model discrimination was assessed with the area under the curve (AUC) method, and calibration with the observed-versus-predicted probability method.

RESULTS

Mean age was 65.4 ± 10.3 year, and 36.5% of patients had prior coronary artery bypass graft. Overall, 41 patients (4.1%) suffered MACE, 9 (0.9%) mortality, 26 (2.6%) acute MI, and 11 (1.1%) required pericardiocentesis. Technical success was achieved in 86.3%. Patients who experienced MACE had higher anatomic complexity, and more often required antegrade dissection/reentry and the retrograde approach. Increasing PROGRESS-CTO MACE scores were associated with increasing MACE rates: 0.5% (score 0-1), 2.4% (score 2), 3.7% (score 3), 4.5% (score 4), 7.8% (score 5), 13.0% (score 6-7). The AUC were as follows: MACE 0.72 (95% confidence interval [CI]: 0.66-0.78), mortality 0.79 (95% CI: 0.66-0.95), pericardiocentesis 0.71 (95% CI: 0.60-0.82), and acute MI 0.57 (95% CI: 0.49-0.66). Calibration was adequate for MACE and mortality, while the models underestimated the risk of pericardiocentesis and acute MI.

CONCLUSIONS

In a large external cohort of patients treated with the hybrid algorithm by experienced CTO operators, the PROGRESS-CTO MACE, mortality, and pericardiocentesis risk scores showed good discrimination, while the acute MI score had inferior performance.

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.

Feasibility, safety and predictors of a successful "blind wiring" antegrade approach in the percutaneous treatment of chronic coronary total occlusions

BACKGROUND

Antegrade wiring using only antegrade guiding catheter without contralateral injection (defined as "blind antegrade wiring") may represent a valid initial treatment strategy for selected chronic coronary total occlusions (CTOs) due to the potentially lower risk of vascular complications. A careful selection of lesions eligible for this strategy as well as an accurate balance between the likelihood of success and failure is paramount. The aim of the study is to determine the rate of successful revascularization, the potential predictors of failure and the incidence of major complications, when using a "blind antegrade wiring" technique.

METHODS

In this multicentric study, consecutive patients with CTO undergoing percutaneous coronary intervention (PCI) were retrospectively screened. All cases approached using "blind antegrade wiring" technique were included.

RESULTS

Out of 155 consecutive CTO-PCIs, 94 involved initial "blind antegrade wiring" strategy. Successful revascularization by means of "blind antegrade wiring" technique was achieved in 73 (78%) patients. Final successful revascularization was obtained in 19 of the remaining 21 procedures with "blind antegrade wiring" failure using other techniques (by adding a second contralateral guiding catheter; 98% total successful revascularization). Logistic regression analysis identified higher J-CTO Score as the only predictor of "blind antegrade wiring" failure. One complication occurred (wire-based coronary perforation).

CONCLUSIONS

"Blind antegrade wiring" may be considered as initial strategy for selected CTO-PCI, mainly for CTOs with low J-CTO Score. This strategy would allow in a substantial number of cases to avoid a priori dual injection, keeping it as secondary strategy in case of "blind antegrade wiring" failure.

Stingray CART (K14 technique): A novel antegrade dissection reentry strategy

A novel device based CART technique (K14 technique) has been described with 2 case examples to illustrate the same. This CART has been performed after ADR and Reverse-CART were unsuccessful.

Impact of Selection Preference on Longer-Term Outcomes between Bioresorbable Vascular Scaffold versus Everolimus-Eluting Stent for True Lumen Tracking-Recanalized Chronic Total Occlusion

Creation of sizable subintima during intervention for chronic total occlusions (CTO) could lead to the key selection preference of metallic stents rather than bioresorbable vascular scaffolds (BVS) and then possibly deviate the outcome comparisons in real-world studies. By including recanalized CTO with true lumen tracking, we tested if any selection preference remained and compared the outcomes between everolimus-eluting stent (EES) and BVS implantation.Among 211 consecutive CTO interventions with true lumen tracking from August 2014 to April 2018 when BVS was available, we compared the clinical and interventional features between 28 patients with BVS and 77 patients with EES implantation. With propensity score matching and a median follow-up of 50.5 (37.3-60.3) months, we further assessed 25 patients with BVS and 25 with EES for target vessel failure (TVF: cardiac death, target vessel myocardial infarction, and target lesion revascularization).Multivariate analyses showed that BVS was still favored in the presence of LAD CTO (odds ratio (OR) = 3.4, 95% confidence interval (CI) = 1.0-11.7) and an average scaffold/stent size ≥ 3 mm (OR = 10.5, 95% CI = 3.0-37.3). EES was preferred for lesions with a J-CTO score ≥ 3 (OR = 19.3, 95% CI = 3.4-110.8) and multivessel intervention necessary at index procedure (OR = 11.3, 95% CI = 1.9-67.3). With matched comparisons, the TVF-free survival of EES was better than that of BVS for CTO recanalization (P = 0.049 by log-rank test) at long-term follow-up.Even with true lumen tracking techniques, selection bias remained substantial when determining either device for CTO implantation. The matched comparison of outcomes suggested the unfavorable longer-term impacts of the first generation of BVS on CTO lesions.