Guiding Principles for Chronic Total Occlusion Percutaneous Coronary Intervention

Intravascular Imaging Improves Clinical Outcomes of Percutaneous Coronary Intervention for Chronic Total Occlusions: A Meta-Analysis of Randomized Controlled Trials

Clinical data comparing intravascular imaging (IVI)-guided percutaneous coronary intervention (PCI) with angiography-guided PCI for chronic total occlusions (CTOs) are limited. This study aimed to compare clinical outcomes of IVI-guided versus angiography-guided PCI in patients with CTOs. A systematic review and meta-analysis were conducted to identify randomized controlled trials (RCTs) comparing IVI-guided with angiography-guided PCI in CTO populations. The primary endpoint was the incidence of major adverse cardiac events (MACE), a composite of death/cardiac death, myocardial infarction (MI), and target-vessel revascularization (TVR). Secondary outcomes included the individual components of MACE. A prespecified subgroup analysis was performed for intravascular ultrasound (IVUS) and optical coherence tomography (OCT). Five RCTs, including 1,296 patients, were analyzed, with 713 (55%) undergoing IVI-guided PCI. Over 1 to 3 years, MACE was significantly lower in the IVI-guided PCI group (7.2% vs 13%; relative risk [RR] 0.55; 95% confidence interval [CI] 0.35 to 0.88; p = 0.012; I² = 31%). In the secondary analysis, TVR incidence was lower in the IVI group (3.1% vs 6.7%; RR 0.52; 95% CI 0.29 to 0.97; p = 0.038). No statistical differences were observed for MI or death/cardiac death. In the IVUS subgroup, MACE was also lower in the IVI-guided PCI group (8.4% vs 14.3%; RR 0.59; 95% CI 0.37 to 0.91; p = 0.019). A trial sequential analysis suggested a low likelihood of type I error. In conclusion, IVI-guided PCI is associated with improved clinical outcomes compared with angiography-guided PCI for the treatment of CTOs.

Antegrade Crossing Techniques for Hard Proximal Occlusion Caps Without the Use of Dedicated Chronic Total Occlusion Devices: A Pictorial Review

One of the main skillsets required to tackle endovascular revascularization of complex peripheral chronic total occlusions (CTOs) is wire crossing into the distal true lumen. There are a lot of factors that influence the use of specific catheter and wire strategies, and these include vessel calcification, occlusion length, previous stents, vessel reconstitution zone, availability of retrograde access, operator experience, and available equipment of the shelf. More than the last 2 decades, various dedicated CTO devices have been developed to meet these specific clinical needs; however, their widespread use has been limited by the lack of availability around the world and considerable cost. Hence, the ability to cross complex lesions with the use of widely available simple catheters and wires is crucial for effective limb salvage in this significantly undertreated patient population. The customization of specific techniques to treat individual patients and anatomical subsets is one of the most creative and innovative aspects of the endovascular revascularization field.Clinical ImpactInfra-inguinal Chronic Total Occlusions recanalisation is considered technically challenging. The conventional manipulation of standard guidewires and catheters has proven to be successful in a considerable percentage of cases but success rate could dramatically drop in presence of challenging lesions. The additional use of retrograde access and re-entry devices could increase technical success but could negatively affect procedural time and overall costs. Twenty different techniques of Chronic Total Occlusions antegrade crossing are hereby described with appropriate schematic representations. The aim is to help operators to apply them in specific anatomy subsets and clinical presentations and ultimately to increase procedural success rate.

Therapeutic Angiogenesis Mediated by Traditional Chinese Medicine: Advances in Cardiovascular Disease Treatment

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese Medicine (TCM) shows growing potential as an adjunct or alternative therapy for vascular occlusion diseases (e.g., stroke, peripheral artery disease) by promoting therapeutic angiogenesis to restore blood flow in ischemic regions while minimizing side effects.

AIMS OF THE STUDY

This review examines TCM-mediated angiogenesis mechanisms and therapeutic advances in vascular occlusion management, establishing a theoretical foundation for clinical translation and precision medicine development.

MATERIALS AND METHODS

We systematically analyzed PubMed articles on TCM-induced angiogenesis in vascular occlusion diseases, focusing on herbal formulations, single herbs, bioactive compounds, and their associated signaling pathways. Search PubMed for studies investigating the role of Chinese herbal medicine (TCM), natural compounds, and herbal medicine in angiogenesis, while excluding research related to cancer, tumor, or oncological contexts.

RESULTS

TCM formulas, individual herbs, and monomeric compounds enhance endothelial cell proliferation, migration, and tube formation via pathways such as HIF/VEGF, PI3K/AKT, NOTCH, BMP/ALK, and Apelin/APJ, improving ischemic blood flow.

CONCLUSION

This review highlights angiogenesis as a novel strategy for vascular occlusive diseases and underscores TCM's efficacy through multi-target angiogenic regulation mechanism.However, further research using modern medical technologies is needed to optimize clinical application and advance precision medicine.

Traditional Versus Dual Lumen Microcatheter-Assisted Parallel Wiring in Chronic Total Occlusion Percutaneous Coronary Intervention: Insights From the PROGRESS-CTO Registry

BACKGROUND

The effectiveness and safety of traditional versus dual lumen microcatheter (DLMC)-assisted parallel wiring in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study.

AIMS

To compare traditional versus dual lumen microcatheter (DLMC)-assisted parallel wiring.

METHODS

We compared the clinical and angiographic characteristics and outcomes of traditional versus DLMC-assisted parallel wiring after failed antegrade wiring (AW) in a large, multicenter CTO PCI registry.

RESULTS

Among 1353 CTO PCIs with failed AW with a single wire, traditional parallel wiring (n = 1081) or DLMC-assisted parallel wiring (n = 272) were utilized at the operator's discretion. The baseline characteristics of patients were similar in both groups except for higher prevalence of diabetes mellitus, and lower prevalence of hypertension, prior heart failure, prior MI and cerebrovascular disease in DLMC patients. Lesions in the DLMC group were more likely to have proximal cap ambiguity, side branch at the proximal cap, blunt/no stump, moderate/severe calcification, and had higher J-CTO score (2.6 ± 1.0 vs. 2.1 ± 1.3, p < 0.001). Technical (87.1% vs. 74.3%, p < 0.001) and procedural (83.8% vs. 75.5%, p = 0.001) success and the incidence of in-hospital major cardiac adverse events (MACE) (4.8% vs. 2.0%, p = 0.020) were higher in the DLMC group. In propensity score matching analysis, DLMC-assisted wiring was associated with higher technical success (odds ratio [OR] 2.17, 95% confidence interval [CI] 1.33-3.54, p = 0.002) and no significant difference in MACE (OR 2.00, 95% CI 0.89-4.50, p = 0.093).

CONCLUSIONS

In lesions that could not be crossed with AW, DLMC-assisted parallel wiring was associated with a higher likelihood of technical success, without an increased risk of MACE, compared with traditional parallel wiring.

Chronic Total Occlusion Percutaneous Coronary Intervention: Present and Future

Chronic total occlusion percutaneous coronary intervention has evolved into a subspecialty of interventional cardiology. Using a variety of antegrade and retrograde techniques, experienced operators currently achieve success rates of 85% to 90%, with an incidence of major periprocedural complications of ≈2% to 3%. Several developments in equipment (new microcatheters and guidewires, novel reentry devices), imaging (computed tomography angiography guidance, intravascular imaging for reentry), techniques (intraocclusion contrast injection, advanced subintimal tracking and reentry), and artificial intelligence (automated computed tomography image analysis and prediction of the likelihood of crossing success with various techniques) could further improve outcomes. Global collaboration and rapid dissemination of new developments accelerate the pace of progress. While innovation is exciting and necessary, adhering to the basic principles of chronic total occlusion percutaneous coronary intervention (such as continual assessment of risks and benefits, meticulous angiographic review, and use of dual injection) remains critical for achieving optimal patient outcomes.

A systematic review and meta-analysis of the use of drug-coated balloon angioplasty for treatment of both de novo and in-stent coronary chronic total occlusions

BACKGROUND

Modern contemporary percutaneous coronary intervention (PCI) techniques with drug-eluting stents (DES) have high procedural success rates in chronic total occlusion (CTO) but with a high prevalence of repeat revascularization. The use of drug-coated balloons (DCBs) in CTO is an alternative treatment strategy. The evidence for DCBs in CTO is, therefore, of interest, and we provide a structured and comprehensive review of the evidence available in terms of the use of DCBs in CTO, including de novo and in-stent (IS) CTO lesions.

OBJECTIVES

We conducted a systematic review and meta-analysis on the use of DCBs in the management of coronary CTO.

METHODS

Electronic databases (PubMed, Embase and Ovid) were systematically searched from inception to April 2024 for DCB CTO studies. A meta-analysis was undertaken using a random-effects inverse-variance method due to heterogeneity. The primary outcome is target lesion revascularization (TLR). Secondary outcomes are major adverse cardiac events (MACE) as a composite of target lesion revascularization (TLR), cardiac death (CD), and any myocardial infarction (MI) including procedural and non-procedural MI, target vessel revascularization (TVR), angiographic outcomes such as late lumen loss (LLL), binary restenosis, and reocclusion.

RESULTS

A total of 10 studies consisting of 1,695 patients were systematically reviewed. This showed that late luminal changes in terms of lumen gain and minimal lumen loss were consistently seen in CTO cohorts 7-12 months after DCB treatment. Five studies were included for meta-analysis with 1,474 patients. There were no significant differences in TLR between treatment strategies such as DCB, DES, and hybrid (DES + DCB) in both de novo and IS-CTO populations as follows: DCB vs DES [OR, 0.71; 95% CI 0.49-1.02], DCB vs DES in IS-CTO [OR, 0.78; 95% CI 0.45-1.34], DCB vs Hybrid [OR, 0.96; 95% CI 0.39-1.43], and hybrid vs DES [OR, 0.76; 95% CI 0.15-3.84]. Similar findings were seen with the MACE outcome. A sensitivity analysis showed no difference between the above-mentioned groups in terms of MI, CD, and TVR.

CONCLUSION

The limited initial evidence on DCB in coronary CTO-PCI suggests a safe and effective alternative treatment strategy and suggests RCTs are, therefore, required.

Efficacy of drug-coated balloon angioplasty for coronary chronic total occlusion: A systematic review and meta-analysis

Percutaneous coronary intervention (PCI) of chronic total occlusions (CTOs) is associated with worse outcomes compared to non-CTO lesions. Whether the implantation of drug-eluting stents (DES) is the cornerstone treatment after successful recanalization of CTO, recent evidence tested the clinical performance of DCB-based PCI, alone or in concert with DES (hybrid DCB/DES approach), in this context. We aimed to conduct a comprehensive, up-to-date systematic review and summary-level meta-analysis of clinical studies comparing outcomes of DCB-based versus DEB-only angioplasty for coronary CTOs. A systematic search was performed to identify all investigations comparing DCB-based versus DES-only angioplasty for coronary CTOs. The primary endpoint was the occurrence of target vessel failure (TVF), a composite outcome of cardiac death, nonfatal myocardial infarction and target vessel revascularization. A total of 5 observational studies (2087 patients) were included in the analysis. The DCB-based PCI group experienced a trend towards a lower rate of TVF (0.45 % (112/25045) vs. 0.76 % (238/31336) person-months, IRR = 0.56 [95 % CI 0.28 to 1.10], I2 = 81 %, p = 0.09) and cardiac death (0.05 % vs. 0.10 % person-months, IRR = 0.55 [95 % CI 0.27 to 1.10], I2 = 0 %, p = 0.09), although a high extent of heterogeneity was observed. Other endpoints were not different between the two groups. In the present meta-analysis, DCB-based PCI was associated with similar outcomes compared to second-generation DES PCI for the treatment of coronary CTOs. Future randomized controlled trials will provide more robust evidence on the effectiveness of DCB in treating coronary CTOs.

Design and rationale of the drug-coated balloon coronary angioplasty versus stenting for treatment of disease adjacent to a chronic total occlusion (Co-CTO) trial

BACKGROUND

Percutaneous coronary intervention (PCI) of chronic total coronary occlusions (CTOs) typically involves extensive drug-eluting stent (DES) implantation. As a result, patients undergoing CTO PCI are exposed to a relatively high risk of in-stent restenosis and target lesion revascularization. While the application of drug-coated balloons (DCBs) may improve patient outcome by reducing stent burden, randomized controlled trials investigating the use of DCB in CTO PCI are lacking.

METHODS

The Co-CTO trial (NCT04881812) is a single-blind, noninferiority randomized controlled trial enrolling 144 patients undergoing CTO PCI. A hybrid strategy (stenting of the CTO body and DCB treatment of adjacent disease) will be compared to a complete stenting strategy. The primary study endpoint is in-segment percentage diameter stenosis at 1 year follow-up determined by intravascular ultrasound. Secondary endpoints include major adverse cardiovascular events (a composite of cardiac death, nonfatal myocardial infarction, and ischemia-driven target lesion revascularization) at 1 year, angiographic outcomes, and cardiac symptoms (Canadian Cardiovascular Society Grading Scale, New York Heart Association Classification of Dyspnea).

CONCLUSION

The Co-CTO trial is the first randomized controlled trial exploring a hybrid strategy (DES + DCB) in patients undergoing CTO PCI.

TRIAL REGISTRATION

Registered at ClinicalTrials.Gov under registration number: NCT04881812 (https://clinicaltrials.gov/study/NCT04881812?cond=cto&intr=drug-coated%20balloon&rank=1).

Patient-centric no-option refractory angina management: establishing comprehensive angina relief (CARE) clinics

INTRODUCTION

Refractory angina (RA) is a debilitating condition characterized by persistent angina despite optimized medical therapy and limited options for further revascularization, leading to diminished quality of life and increased healthcare utilization. The RA patient population is rapidly expanding with significant unmet needs. Specialty clinics should be developed to focus on the long-term efficacy and safety of clinically available and novel treatment strategies, emphasizing quality of life.

AREAS COVERED

Patient-focused Comprehensive Angina Relief (CARE) clinics can enhance care and outcomes by providing individualized management for complex RA. This review summarizes peer-reviewed articles from PubMed and trial data from ClinicalTrials.gov. We discuss the epidemiology and pathophysiology of RA, introduce standardized tools for evaluating angina and psychosocial factors, and address symptom management. We also review treatment options such as risk factor modification, medication, and complex revascularization. Additionally, we explore emerging therapies, including coronary sinus occlusion, regenerative therapy, and neuromodulation for 'no-option' RA.

EXPERT OPINION

In the next five years, patients with refractory chest pain with or without coronary artery disease will increasingly be referred to specialty clinics for follow-up. Conducting more randomized control clinical trials with larger population subsets will bring novel therapies to the forefront.

Effect of Interval Time after Subintimal Plaque Modification on the Success Rate of Future Recanalization for Chronic Total Occlusion Percutaneous Coronary Interventions

Background

Chronic total occlusion (CTO) is a complex and difficult type of coronary lesion for which elective secondary intervention after subintimal plaque modification (SPM) can improve the success rate. This study sought to determine the most appropriate timing for secondary interval interventions to maximize the benefit to the patient.

Methods

This study retrospectively included patients who failed their first CTO percutaneous coronary intervention (PCI) at Beijing Anzhen Hospital Department of Cardiology from January 2019 to December 2022. We reviewed the clinical characteristics, procedural features, and outcomes of patients who underwent SPM and returned to our institution for a second CTO-PCI.

Results

Of the 2847 patients who visited our institution between January 2019 and December 2022, 528 underwent SPM and returned to our institution on an elective basis for a secondary procedure. Of these, 236 procedures were performed within 30 days (Group I), and 292 were performed between 30 and 90 days (Group II). After the intervention, the occluded segment was successfully opened in 170 (72.0%) Group I and 248 (84.9%) Group II participants. When analyzing the factors for operational failure, we found that different intervals, diabetes mellitus, hyperlipidemia, and a history of previous PCI or percutaneous coronary angioplasty (PTCA) were the reasons for the secondary intervention failure. When analyzing the safety of the procedure, we found that pericardial effusion was the most common complication after the procedure, with an incidence of 7.4%. There was no notable variation in the incidence of pericardial effusion between the two groups, 8.9% vs. 6.2% (p = 0.232).

Conclusions

Higher success rates were observed when secondary procedures were performed between 30 and 90 days instead of within 30 days after the initial CTO-PCI SPM, with no significant difference in safety noted between the two groups.

The Prevalence and Impact of Atrial Fibrillation on Patients with Chronic Total Occlusions: Insights from the National Inpatient Sample

The impact of atrial fibrillation (AF) on patients with chronic total occlusions (CTOs) at the national level remains unclear. In this study, we conducted a retrospective analysis of data from the National Inpatient Sample to assess the characteristics and in-hospital outcomes of patients with CTO based on the presence or absence of AF. Multiple logistic and linear regressions examined factors associated with AF and evaluated its impact on length of stay (LoS), cost, and mortality. The analysis included 480,180 patients diagnosed with CTO, with AF present in 28.0% of cases. Patients with CTOs and AF were older (median age 73 vs. 66 years, p < 0.001) and exhibited lower female representation (25.0% vs. 27.9%, p < 0.001). Factors most strongly associated with AF included previous heart failure (OR 1.98, 95% CI 1.92-2.05, p < 0.001), liver disease (OR 1.37, 95% CI 1.27-1.48, p < 0.001), and obesity (OR 1.25, 95% CI 1.20-1.30, p < 0.001). AF correlated with increased in-hospital mortality (OR 1.29, 95% CI 1.18-1.40, p < 0.001), ischemic stroke (OR 1.27, 95% CI 1.13-1.42, p < 0.001), and major bleeding (OR 1.38, 95% CI 1.30-1.46). Moreover, AF was associated with a longer LoS (coef 1.58, 95% CI 1.50 to 1.67, p < 0.001) and higher in-hospital costs (coef 6.22, 95% CI 5.81 to 6.63, p < 0.001). Patients with CTOs and AF were older and had more underlying health problems compared to patients without AF. The patients with AF have worse outcomes in terms of mortality, ischemic stroke, major bleeding, length of stay, and costs.

Review and Key Takeaways of the 2021 Percutaneous Coronary Intervention Guidelines

The 2021 Percutaneous Coronary Intervention guidelines completed by American College of Cardiology/American Heart Association/Society for Cardiovascular Angiography and Interventions provide a set of guidelines regarding revascularization strategies. With emphasis on equity of care, multidisciplinary heart team use, revascularization for acute coronary syndrome, and stable ischemic heart disease, the guidelines create a thorough framework with recommendations regarding therapeutic strategies. In this comprehensive review, our aim is to summarize the 2021 revascularization guidelines and analyze key points regarding each recommendation.

Insights into the Global Total Occlusion Crossing Algorithm

An algorithmic approach to chronic total occlusion (CTO) percutaneous coronary intervention has led to an increase in the success rate and safety of the procedure. The global CTO crossing algorithm is a consensus document that was developed by 121 expert operators from 50 countries and published during the COVID-19 pandemic. It provides standardisation while allowing flexibility in CTO crossing strategy selection, and can facilitate teaching of CTO percutaneous coronary intervention across various regions of the world. In this review, the 10 steps of the global CTO crossing algorithm are discussed in detail.

Recent Advances in Coronary Chronic Total Occlusions

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

Indications, Management, and Short- and Medium-Term Outcomes of Patients with Chronic Coronary Occlusion Treated with Percutaneous Revascularization-A Single-Center Study

The diagnosis of chronic total occlusion (CTO), characterized by the complete obstruction of a coronary artery for at least three months, remains challenging and can be entirely asymptomatic. Since the indications for performing a recanalization procedure for CTO do not originate from randomized controlled trials, this study aimed to assess the indications, management, and procedural outcomes of patients undergoing percutaneous revascularization (PCI) for a CTO, ensuring that the population was as uniform as possible regarding technologies and methodological approaches. Forty-one consecutive patients who underwent PCI for CTO recanalization were enrolled from January 2021 to 2024. Additional outcomes included mortality, major adverse cardiovascular events, and the presence of residual cardiac symptoms, with a median follow-up of 449 days and an interquartile range of 230-643 days. Our real-life study confirmed that PCI for CTO has a high success rate and a low incidence of major complications.

Revascularization of Chronic Total Occlusions vs. Planned Complex Percutaneous Coronary Intervention: Long-Term Outcomes and Mortality

Introduction: The number of chronic total occlusion (CTO) revascularization procedures has continuously increased, obtaining better results in recent years. However, there are few data regarding long-term outcomes and no comparisons to planned complex non-CTO percutaneous coronary intervention (PCI). Methods: We included all patients undergoing planned complex PCI. Our main objective was to compare a combined endpoint of all-cause death, myocardial infarction, and target vessel revascularization at the long-term follow-up of CTO PCI versus planned complex non-CTO PCI. We compared the groups using multivariable Cox regression and performed a propensity score matching analysis to control the baseline characteristics. We repeated the analysis for the separate components of the primary endpoint. Results: From January 2018 to June 2023, 1394 complex coronary PCIs were performed at our center. After excluding 393 non-planned cases, 201 CTO PCIs and 800 non-CTO PCIs were included. The mean follow-up was 2.5 ± 1.5 years. The composite endpoint occurred in 23 (11.6%) CTO PCIs and 219 (28.2%) planned non-CTO PCIs. The multivariable Cox regression using the CTO group as the reference showed a lower risk for the primary outcome (HR: 0.59; 95% CI 0.37-0.95; p = 0.031). After matching, a total of 195 adequately balanced pairs were obtained. The CTO group presented a lower risk for the primary combined outcome (HR: 0.46; 95% CI 0.27-0.76; p = 0.003). Conclusions: In patients undergoing planned complex PCI, those in the CTO group presented a reduced risk of all-cause death, myocardial infarction, and target vessel revascularization at the end of the follow-up.

Optimizing the Approach and Clinical Outcomes of Women Undergoing Chronic Total Occlusion-Percutaneous Coronary Intervention

Coronary artery disease remains a leading cause of morbidity and mortality globally, with chronic total occlusions (CTOs) representing a particularly challenging subset. Percutaneous coronary intervention (PCI) for CTOs has evolved significantly over the years, driven by advancements in equipment, techniques, and operator expertise. However, women have historically been underrepresented in clinical trials and guidelines, leading to a gap in an evidence-based management tailored to their specific needs, including in CTO-PCI. This review aims to explore the nuances of CTO-PCI in women, including anatomic considerations, procedural strategies, and clinical outcomes, with the goal of optimizing their care.

Utility of Cardiovascular CT in Ischemic Heart Disease

Cardiac computed tomography angiography (CCTA) has acquired a pivotal role in modern cardiology. It represents the gold standard for noninvasive coronary imaging. Moreover, CCTA permits a comprehensive evaluation of atheromatic burden and plaque composition. This study aims to review the impact of CCTA across the different presentations of ischemic heart disease, from primary prevention to the evaluation of patients requiring revascularization.

Retrograde approach to chronic total occlusion percutaneous coronary interventions- Technique and outcomes

The retrograde approach to chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has significantly contributed to the success rates of CTO PCI. It is usually performed in complex CTO lesions, in which the antegrade approach is not feasible or fails. In this article we discuss the steps to perform retrograde CTO PCI and its complications and success rates. Considering the moderate to high success rates of the retrograde approach in the hands of experienced operators and higher complication rates than antegrade only procedures, optimizing the safety of retrograde CTO PCI is of paramount importance.

Short- and long-term outcomes of antegrade versus retrograde approaches in patients undergoing percutaneous coronary intervention for chronic total occlusion: A meta-analysis

BACKGROUND

Chronic Total Occlusion (CTO) involves severe coronary artery blockage that impairs blood flow and affects 15-20 % of patients undergoing coronary angiography and over 40 % with diabetes or heart failure. Percutaneous Coronary Intervention (PCI) is used to restore blood flow in such cases. The retrograde approach, developed due to lower success with the antegrade method in complex cases, improves outcomes but increases complications. This meta-analysis compares the efficacy and safety of both approaches to guide clinical practice.

METHODS

A comprehensive literature search was conducted on PubMed, Embase, Google Scholar, and Scopus until June 5, 2024, to find studies comparing antegrade and retrograde approaches in CTO-PCI patients. Pooled risk ratios (RR) with 95 % confidence intervals (CI) were calculated using R software (version 4.4.1), with significance set at p < 0.05. Random-effects models were used for all analyses.

RESULTS

Our analysis included 22 observational studies with 49,152 CTO-PCI patients: 35,844 in the antegrade arm and 13,308 in the retrograde arm. The antegrade approach showed significantly lower risks of in-hospital outcomes, including mortality [RR: 0.45; p < 0.001], myocardial infarction [RR: 0.37; p < 0.001], major adverse cardiovascular events [RR: 0.34; p < 0.001], and cerebrovascular events [RR: 0.50; p = 0.011]. Long-term outcomes, such as all-cause mortality [RR: 0.71; p = 0.157] and myocardial infarction [RR: 0.76; p = 0.438], were comparable between both approaches.

CONCLUSION

The antegrade technique shows better outcomes and procedural advantages over retrograde revascularization, though long-term outcomes are similar. Further studies, especially randomized controlled trials are needed to confirm these findings.

Postprocedural Contrast-Associated Acute Kidney Injury and Prognosis of Patients Undergoing Recanalization of Chronic Total Occlusions

Introduction: Percutaneous coronary intervention (PCI) for chronic total occlusions (CTOs) requires advanced techniques and prolonged procedural efforts, often necessitating high contrast volumes, which may increase the risk of contrast-associated acute kidney injury (CA-AKI). However, evidence suggests that factors beyond contrast exposure contribute to CA-AKI, though data specific to CTO PCI remain limited. Methods: Patients undergoing contemporary CTO PCI at our university-affiliated tertiary care center were enrolled. CA-AKI was defined according to KDIGO criteria, and patients were stratified based on the presence of postprocedural CA-AKI. Baseline and procedural characteristics, including osmotic factors, were compared between the groups. The primary outcome was all-cause mortality at one year, and the secondary outcome was all-cause mortality at three years. Results: A total of 145 patients were enrolled, with a mean age of 67 years, and 75% were male. Baseline creatinine levels, electrolytes, and osmotic factors did not differ significantly between groups. Lesion parameters and J-CTO scores were also comparable. The contrast volume and procedural duration were numerically higher in patients who developed CA-AKI. Patients with CA-AKI received a higher radiation dose (22.1 vs. 13.2 Gy·cm2, p = 0.041). CA-AKI emerged as an independent predictor of all-cause mortality at one year (adjusted HR 5.3, CI [1.52-18.51], p = 0.009) but not at three years. Conclusions: In this retrospective analysis, CA-AKI was an independent predictor of all-cause mortality at one year following CTO PCI but lost predictive value at three years. Baseline renal function and contrast volume alone did not predict CA-AKI. Instead, procedural complexity, reflected by higher radiation exposure, was associated with an elevated risk of CA-AKI.

Preprocedural Planning for Chronic Total Occlusion Percutaneous Coronary Intervention

Chronic total occlusions (CTO) are frequently encountered in clinical practice. Although the success rates and safety of CTO percutaneous coronary intervention (PCI) have significantly improved with the development of newer equipment, use of an algorithmic approach, and advancement in procedural techniques, CTO PCI has a higher rate of complication than does non-CTO PCI. Therefore, meticulous preprocedural planning before CTO PCI is paramount to improve success and reduce the risk of complications. In this report, we review multiple aspects of preprocedural CTO PCI planning, including procedural indications, efficacy, safety, diagnostic angiography, scoring tools for procedural success and risk prediction, and preprocedural use of computed tomography coronary angiography.

Can Contrast Injections Cause or Propagate Coronary Injuries? Insights From Vessel and Guiding Catheter Hemodynamics

Background

The mechanistic association between the hydraulic forces generated during contrast injection and the risk of coronary injury is poorly understood. In this study, we sought to evaluate whether contrast injections increase intracoronary pressures beyond resting levels and estimate the risk of hydraulic propagation of coronary dissections.

Methods

This is a prospective, single-arm, multicenter study that included patients with nonculprit, non-flow-limiting coronaries. A continuous 60-second pressure recording was taken at 5 predetermined locations during contrast injections: distal, mid, and proximal vessel, catheter tip, and inside the catheter. The primary end point was the change in intracoronary peak pressure between resting and injections in each location.

Results

A total of 269 pressure recordings (58 vessels; 52 patients) were analyzed. Injections led to a small increase in peak pressure in the distal (mean difference, +4.5 mm Hg; 95% CI, 1.5-7.4), mid (mean difference, +4.1 mm Hg; 95% CI, 1.4-6.9), and proximal (mean difference, +5.1 mm Hg; 95% CI, 2.5-7.7) vessel locations, and much higher increases at the catheter tip (mean difference, +11.7 mm Hg; 95% CI, 5.8-17.7) and inside the catheter (mean difference, +77.5 mm Hg; 95% CI, 64.5-90.4). Compared to the distal vessel, pressure changes were only significant at the catheter tip (+10 mm Hg; P < .01) and inside the catheter (+79.1 mm Hg; P < .01).

Conclusions

Contrast injections lead to negligible changes in intracoronary pressures beyond the catheter tip. Although it is sensible to minimize injections when coronary dissections are close to the catheter, it is unlikely that they would cause injuries beyond the catheter tip.

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

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

Wire Escalation And De-escalation Techniques in Antegrade and Retrograde Approaches to Chronic Total Occlusion Percutaneous Coronary Interventions

Coronary chronic total occlusions (CTO) are frequently identified during coronary angiography and remain the most challenging subset of coronary artery lesions to treat; however, advancements in techniques and materials have greatly improved success rates. Various crossing algorithms have been developed to standardise the approach to CTO interventions based on angiographic criteria. Antegrade wiring is typically the initial strategy of choice, particularly in cases of short and straight CTOs with tapered proximal cap. Similarly, retrograde crossing can be achieved through retrograde wiring, although this approach has a very low success rate. This review aims to outline how to perform a CTO analysis, clarify the fundamental features of guidewires and provide insights into both antegrade and retrograde wire-based approaches.

Side branch preservation using tip detection-antegrade dissection re-entry after failed subintimal tracking and re-entry in chronic total occlusion: a case report

Background

Techniques for treating difficult chronic total occlusions (CTOs) have evolved with the discovery of the tip detection-antegrade dissection re-entry (TDADR) guided by intravascular ultrasound (IVUS). This case demonstrates TDADR as a viable bailout in failed subintimal tracking and re-entry (STAR) technique.

Case summary

A 78-year-old man with stable angina on optimal medical therapy had exertional angina pectoris secondary to a residual CTO lesion of the left circumflex coronary (LCX) artery. Percutaneous coronary intervention was performed for a mid-LCX CTO with a blunt proximal stump where the dissection plane expanded along the main vessel and side branch 2. Due to lack of promising collaterals for the retrograde approach, STAR successfully recanalized side branch 1. As main vessel failed to be recanalized, we proceeded with an AnteOwl IVUS-guided TDADR, intending guidewire penetration into the true lumen from the middle of the dissection plane at the main vessel, proximal to side branch 2 origin. Accurate wiring was achieved, and a guidewire was placed on side branch 2 for protection. After stent placement in the main vessel and kissing inflation, cutting balloon dilatation was performed to create re-entries for the STAR-induced extended main vessel haematoma. The procedure resulted in complete revascularization of main vessel and side branches. At 12-month follow-up, no further angina was reported, and coronary computed tomography showed patent side branches with no significant in-stent restenosis.

Discussion

Imaging-based TDADR method was effective in our present case despite failed STAR technique. Limited IVUS and operator availability may become a barrier in implementing TDADR.

Retrograde approach for recanalization in stumpless chronic total occlusion: A case report

Chronic total occlusive disease of the coronary arteries is the most challenging disease in the field of coronary intervention. When the anterograde approach is not feasible, the retrograde approach remains the only strategy.

Knuckle Guidewires to Create Dissections in Chronic Total Occlusion Percutaneous Coronary Intervention: Position Statement

Dissection and re-entry techniques are essential to achieve safe and effective chronic total occlusion recanalization. Several studies have demonstrated similar outcomes following extraplaque stenting compared with intraplaque stenting. Dissection techniques most often involve the use of knuckled wires to progress within and beyond the chronic total occlusion segment. In this expert consensus document, the authors compare the properties of different polymer-jacketed wires for their use in dissection techniques. The authors also describe 2 principal knuckle wire behaviors, the rolling and the traveling knuckles. Finally, several adjunctive techniques for safer dissection are described.

The impact of successful chronic total occlusion percutaneous coronary intervention on clinical outcomes: a tertiary single-center analysis

Background

The benefit of chronic total occlusion (CTO)-percutaneous coronary intervention (PCI) is controversial because of a lack of high-quality evidence. We aim to evaluate the impact of CTO-PCI on symptoms, quality of life and mortality.

Methods

We conducted a retrospective single center study of patients with CTO-PCI in a tertiary center in Austria. The study outcomes were Canadian Cardiovascular Society (CCS) angina score, quality of life measured by Seattle Angina Questionnaire (SAQ), and death at median follow up for patients with successful vs. failed CTO-PCI.

Results

A total of 300 patients underwent CTO-PCI for coronary artery disease, of which 252 (84%) were technically successful with median follow up of 3.4 years. There were no significant differences in in-hospital or all-cause mortality, major adverse cardiovascular event, or stent-related complications between the groups of failed and successful CTO-PCI. Among patients with successful CTO-PCI there was a significant improvement in CCS score, which was not found for the group with failed CTO-PCI. Successful reopening was associated with significant benefits of the SAQ domains of angina with stressful activity [3.7 ± 0.9 vs. 3.1 ± 0.5, p = 0.004, use of nitrates (4.7 ± 0.5 vs. 3.0 ± 1.0) p = 0.005] and satisfaction from angina relief (4.4 ± 1.1 vs. 3.6 ± 1.4 p < 0.001).

Conclusion

While there was no significant difference in mortality, successful CTO-PCI was associated with greater reduction in angina and the use of nitrates compared to unsuccessful CTO-PCI.

The Role of Coronary Imaging in Chronic Total Occlusions: Applications and Future Possibilities

Chronic total occlusions (CTOs) represent a challenging scenario in coronary artery disease (CAD). The prevalence of CTOS in patients undergoing coronary angiography underscores the need for effective diagnostic and therapeutic strategies. Coronary angiography, while essential, offers limited insights into lesion morphology, vessel course, and myocardial viability. In contrast, coronary imaging techniques-including optical coherence tomography (OCT), intravascular ultrasound (IVUS), and coronary computed tomography angiography (CCTA)-provide comprehensive insights for each stage of CTO percutaneous coronary intervention (PCI). OCT facilitates the assessment of plaque morphology and stent optimization, despite low evidence and several limitations in CTO-PCI. IVUS offers deeper penetration, allowing managing proximal cap scenarios and guiding subintimal navigation. CCTA provides a non-invasive, three-dimensional view of coronary anatomy, enabling the precise evaluation of myocardial mass at risk and detailed procedural planning. Despite their individual limitations, these imaging modalities have enhanced the success rates of CTO-PCI, thus reducing procedural and long-term complications and improving patient outcomes. The future of CTO management lies in further technological advancements, including hybrid imaging, artificial intelligence (AI) integration, and improved fusion imaging. These innovations promise to refine procedural precision and personalize interventions, ultimately improving the care of patients with complex coronary artery disease.

Impact of cigarette smoking on long-term clinical outcomes in patients with coronary chronic total occlusion lesions

Cigarette smoking is a significant risk factor for coronary artery disease. However, there is insufficient evidence regarding the long-term clinical effects of smoking in Asian populations with chronic total occlusion (CTO). This study aimed to assess the effects of smoking on 5-year (median follow-up period, 4.2 ± 1.5 [interquartile range, 4.06-5.0] years) clinical outcomes in patients with CTO lesions who underwent percutaneous coronary intervention (PCI) or medical treatment (MT). We enrolled 681 consecutive patients with CTO who underwent diagnostic coronary angiography and subsequent PCI or MT. The patients were categorized into smokers (n = 304) and nonsmokers (n = 377). The primary endpoint was major adverse cardiovascular events (MACE), including a composite of all-cause death, myocardial infarction, and revascularization over a 5-year period. Propensity score matching (PSM) analysis was performed to adjust for potential baseline confounders. After PSM analysis, two propensity-matched groups (200 pairs, n = 400) were generated, and the baseline characteristics of both groups were balanced. The smokers exhibited a higher cardiovascular risk of MACE (29.5% vs. 18.5%, p = 0.010) and non-TVR (17.5 vs. 10.5%, p = 0.044) than the nonsmokers. In a landmark analysis using Kaplan-Meier curves at 1 year, the smokers had a significantly higher rate of MACE in the early period (up to 1 year) (18.8% and 9.2%, respectively; p = 0.008) compared with the nonsmokers. The Cox hazard regression analysis with propensity score adjustment revealed that smoking was independently associated with an increased risk of MACE. These findings indicate that smoking is a strong cardiovascular risk factor in patients with CTO, regardless of the treatment strategy (PCI or MT). In addition, in the subgroup analysis, the risk of MACE was most prominently elevated in the group of smokers who underwent PCI.

Remote proctoring in complex percutaneous coronary intervention aided by mixed reality technology

Aims

Percutaneous coronary intervention (PCI) of chronic total occlusions (CTOs) has a lower success rate and a higher complication rate compared to PCI of non-occluded coronary arteries. Co-operation and supervision by a more experienced operator (proctoring) are associated with improved success of CTO procedures. This study aims to assess the feasibility of remote proctoring using web-based communication and mixed reality technology in CTO procedures.

Methods and results

The PCI operator was equipped with a Microsoft HoloLens 2 head-mounted display enabling visual and verbal interaction including holographic annotations with a remote proctor. Ten CTO procedures were performed by a single PCI operator assisted by a remote proctor. Audio and video communication was successfully established in all procedures. All procedures were possible to perform with a Microsoft HoloLens 2 head-mounted display. The PCI operator experienced the remote proctoring as useful.

Conclusion

Remote proctoring of CTO procedures using mixed reality technology was feasible. The impact of the method regarding procedural and patient outcomes needs to be assessed in new studies.

Association between hibernating myocardium and collateral circulation in patients with coronary chronic total occlusion

Objective

To explore the association between the quantity of hibernating myocardium (HM) and collateral circulation in patients with coronary chronic total occlusion (CTO).

Materials and methods

88 CTO patients were retrospectively analyzed who underwent evaluation for HM using both 99mTc-sestamibi Single photon emission computed tomography (99mTc-MIBI SPECT) myocardial perfusion imaging (MPI) combined with 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) myocardial metabolism imaging (MMI). They were divided into two groups according Rentrop grading: the poorly/well-developed collateral circulation group (PD/WD group, Rentrop grades 0-1/2-3). After adjusting for the potential confounding factors and conducting a stratified analysis, we explored the association between the HM index within CTO region and the grading of collateral circulation.

Results

In the WD group, the HM index was notably higher than PD group (46.2 ± 15.7% vs. 20.9 ± 16.7%, P < 0.001). When dividing the HM index into tertiles and after adjusting for potential confounders, we observed that the proportion of patients with WD rose as the HM index increased (OR: 1.322, 95% CI: 0.893-1.750, P < 0.001), the proportion of patients with WD was 17.4%, 63.3%, and 88.6% for Tertile 1 to Tertile 3.This increasing trend was statistically significant (OR: 1.369, 95% CI: 0.873-1.864, P < 0.001), especially between Tertile 3 vs. Tertile 1 (OR: 4.330, 95% CI: 1.459-12.850, P = 0.008). Curve fitting displaying an almost linear positive correlation between the two.

Conclusion

The HM index within CTO region is an independent correlation factor for the grading of coronary collateral circulation. A greater HM index corresponded to an increased likelihood of WD.

Complete percutaneous coronary revascularization: An elegant solution to left ventricular dysfunction caused by severe coronary artery disease

With increased complexity in both medical comorbidities and coronary anatomy, the proportion of surgically turndown patients and high-risk PCI will continue to rise. Impella-assisted complex PCI can be performed with high technical success and can improve quality of life, angina score, and potentially left ventricular ejection fraction.

Predicting Successful Chronic Total Occlusion Crossing With Primary Antegrade Wiring Using Machine Learning

BACKGROUND

There is limited data on predicting successful chronic total occlusion crossing using primary antegrade wiring (AW).

OBJECTIVES

The aim of this study was to develop and validate a machine learning (ML) prognostic model for successful chronic total occlusion crossing using primary AW.

METHODS

We used data from 12,136 primary AW cases performed between 2012 and 2023 at 48 centers in the PROGRESS CTO registry (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention; NCT02061436) to develop 5 ML models. Hyperparameter tuning was performed for the model with the best performance, and the SHAP (SHapley Additive exPlanations) explainer was implemented to estimate feature importance.

RESULTS

Primary AW was successful in 6,965 cases (57.4%). Extreme gradient boosting was the best performing ML model with an average area under the receiver-operating characteristic curve of 0.775 (± 0.010). After hyperparameter tuning, the average area under the receiver-operating characteristic curve of the extreme gradient boosting model was 0.782 in the training set and 0.780 in the testing set. Among the factors examined, occlusion length had the most significant impact on predicting successful primary AW crossing followed by blunt/no stump, presence of interventional collaterals, vessel diameter, and proximal cap ambiguity. In contrast, aorto-ostial lesion location had the least impact on the outcome. A web-based application for predicting successful primary AW wiring crossing is available online (PROGRESS-CTO website) (https://www.progresscto.org/predict-aw-success).

CONCLUSIONS

We developed an ML model with 14 features and high predictive capacity for successful primary AW in chronic total occlusion percutaneous coronary intervention.

Impact of Bifurcation Involvement and Location in Chronic Total Occlusion Percutaneous Coronary Intervention: Insights From the EuroCTO Registry

Bifurcation involvement close to or within the occluded segment poses increasing difficulties for chronic total occlusion (CTO)-percutaneous coronary intervention (PCI). However, this variable is not considered in the angiography-based CTO scoring systems nor has been extensively investigated in large multicenter series. Accordingly, we analyzed a CTO-PCI registry involving 92 European centers to explore the incidence, angiographic and procedural characteristics, and outcomes specific to CTO-PCIs with bifurcation involvement. A total of 3,948 procedures performed between January and November 2023 were examined (33% with bifurcation involvement). Among bifurcation lesions, 38% and 37% were located within 5 mm of the proximal and distal cap, respectively, 16% within the CTO body, and in 9% of cases proximal and distal bifurcations coexisted. When compared with lesions without bifurcation involvement, CTO bifurcation lesions had higher complexity (J-CTO 2.33 ± 1.21 vs 2.11 ± 1.27, p <0.001) and were associated with higher use of additional devices (dual-lumen microcatheter in 27.6% vs 8.4%, p <0.001, and intravascular ultrasound in 32.2% vs 21.7%, p <0.001). Radiation dose (1,544 [836 to 2,819] vs 1,298.5 [699.1 to 2,386.6] mGy, p <0.001) and contrast volume (230 [160 to 300] vs 190 [130 to 250] ml, p <0.001) were also higher. Technical success was similar (91.5% with bifurcation involvement vs 90.4% without bifurcation involvement, p = 0.271). However, the bifurcation lesions within the CTO segment (intralesion) were associated with lower technical success than the other bifurcation-location subgroups (83.7% vs 93.3% proximal, 93.4% distal, and 89.0% proximal and distal, p <0.001). On multivariable analysis, the presence of an intralesion bifurcation was independently associated with technical failure (odds ratio 2.04, 95% confidence interval 1.24 to 3.35, p = 0.005). In conclusion, bifurcations are present in approximately one-third of CTOs who underwent PCI. PCI of CTOs with bifurcation can be achieved with high success rates except for bifurcations within the occluded segment, which were associated with higher technical failure.

Safety and Effectiveness of a Novel Microcatheter in Coronary Chronic Total Occlusions-The BIOMICS Study

Background

Chronic total occlusion (CTO) remains the most complex anatomical subset of lesions in percutaneous coronary intervention (PCI), often requiring advanced techniques and technologies, including the use of microcatheters.

Methods

The BIOMICS study is a premarket first-in-human prospective, multicenter, open-label, single-arm trial investigating the safety and efficacy of a novel coronary microcatheter (BioMC, Biosensors International) in 100 patients with symptoms of ischemia undergoing elective CTO-PCI. The primary efficacy end point of the study was device success defined according to the CTO-ARC (Chronic Total Occlusion Academic Research Consortium) criteria namely the ability of the microcatheter to successfully facilitate placement of a guide wire beyond the occluded coronary segment. The primary safety end point was the incidence of in-hospital cardiac death or myocardial infarction at hospital discharge.

Results

Hundred patients were recruited between March 2022 and January 2023. The primary efficacy end point was achieved in 75% of patients (95% CI, 65.3%-83.1%; P < .0001 for superiority compared to the prespecified performance goal of 54%). The primary safety end point of in-hospital cardiac death or myocardial infarction was observed in 2% of the patients. There were no study device-related coronary perforations or device failures.

Conclusions

The use of a novel coronary microcatheter during CTO-PCI was associated with a high device success and an excellent safety profile.

Is it Worthy Enough to Revascularize Chronically Occluded Coronaries?

Chronic total occlusions (CTOs) represent the "final frontier" of coronary interventions with the lowest procedural success rates and the most common reason for incomplete revascularization and referral to coronary artery bypass graft surgery (CABG). CTO lesions are not an infrequent finding during coronary angiography. They are often responsible for enhancing the complexity of the coronary disease burden thereby affecting the final interventional decision in the process. Notwithstanding the modest technical success of CTO-PCI, most of the earlier observational data demonstrated a clear survival benefit free of major cardiovascular events (MACE) in patients undergoing successful CTO revascularization. However, data from recent randomized trials fail to uphold the same survival advantage albeit, showing some trend toward improvement in left ventricular function, quality of life indicators and freedom from fatal ventricular arrythmia. Various guidance statements propose a well-defined role for CTO intervention in specific situations provided criterions for patient selection, appreciable inducible ischemia, myocardial viability and cost-risk-benefit analysis are met.

Global Consensus Recommendations on Improving the Safety of Chronic Total Occlusion Interventions

Safety is of critical importance to chronic total occlusion (CTO) percutaneous coronary intervention (PCI). This global consensus statement provides guidance on how to optimise the safety of CTO) PCI, addressing the following 12 areas: 1. Set-up for safe CTO PCI; 2. Guide catheter--associated vessel injuries; 3. Hydraulic dissection, extraplaque haematoma expansion, and aortic dissections; 4. Haemodynamic collapse during CTO PCI; 5. Side branch occlusion; 6. Perforations; 7. Equipment entrapment; 8. Vascular access considerations; 9. Contrast-induced acute kidney injury; 10. Radiation injury; 11 When to stop; and, 12. Proctorship. This statement complements the global CTO crossing algorithm; by advising how to prevent and deal with complications, this statement aims to facilitate clinical practice, research, and education relating to CTO PCI.

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.

Impact of successful antegrade and retrograde CTO PCI on short-term prognosis

BACKGROUND

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) carries risk of complications and should be attempted when the anticipated benefits exceed the potential risks. The primary indication for CTO-PCI is symptom improvement. However, the impact of CTO-PCI on angina and subsequent incidence of major adverse cardiovascular event (MACE) rate remains controversial. Our aim was to study the impact of technically successful elective CTO-PCI on the procedural success rate and short-term MACE. The current study was a prospective cohort study that included a total of 80 patients who were referred to our center (Ain Shams University Hospitals) for elective CTO-PCI and underwent technically successful CTO-PCI. Data were collected on patient arrival to our department, and then, the patients were observed during hospital admission to record any In-Hospital MACE. These patients were then followed up for 6 months to record improvement or worsening of their symptoms and to assess occurrence of any MACE including hospitalization and undergoing symptom-driven coronary angiography.

RESULTS

The mean age of our patients was 56 ± 9.6 years, and 73 patients (91%) were men. Sixty-two patients (77.5%) were done via an antegrade approach, and 18 patients (22.5%) were done via a retrograde approach with an overall procedural success rate of 91.25% (antegrade 93.5%, retrograde 83.3%). The overall mean procedure time was 102 min, the mean contrast volume used was 371 ml, and the mean cumulative air kerma dose was 7.2 Gy. The retrograde group required longer procedure times, larger volumes of contrast and higher exposure to radiation. The overall in-hospital MACE was 8.75%. Sixty-five patients in our study (81.25%) showed an improvement in the grade of their exertional dyspnea or angina within the 6-month follow-up period. Thirteen patients in our study (16.25%) needed re-hospitalization within a 6-month period after PCI. The overall target lesion revascularization rate at 6 months was 8.75%.

CONCLUSIONS

Technically successful CTO PCI in a well-equipped center with highly qualified CTO operators resulted in high procedural success rates and low incidence of short-term MACE.

Ten-Year Outcome of Recanalization or Medical Therapy for Concomitant Chronic Total Occlusion After Myocardial Infarction

BACKGROUND

The EXPLORE (Evaluating Xience and Left Ventricular Function in PCI on Occlusions After STEMI) trial was the first and only randomized trial investigating chronic total occlusion (CTO) percutaneous coronary intervention (PCI) early after primary PCI for ST-segment-elevation myocardial infarction, compared with medical therapy for the CTO. We performed a 10-year follow-up of EXPLORE to investigate long-term safety and clinical impact of CTO PCI after ST-segment-elevation myocardial infarction, compared with no-CTO PCI.

METHODS AND RESULTS

In EXPLORE, 302 patients post-ST-segment-elevation myocardial infarction with concurrent CTO were randomized to CTO PCI within ≈1 week or no-CTO PCI. We performed an extended clinical follow-up for the primary end point of major adverse cardiac events, consisting of cardiovascular death, coronary artery bypass grafting, or myocardial infarction. Secondary end points included all-cause death, angina, and dyspnea. Median follow-up was 10 years (interquartile range, 8-11 years). The primary end point occurred in 25% of patients with CTO PCI and in 24% of patients with no-CTO PCI (hazard ratio [HR], 1.11 [95% CI, 0.70-1.76]). Cardiovascular mortality was higher in the CTO PCI group (HR, 2.09 [95% CI, 1.10-2.50]), but all-cause death was similar (HR, 1.53 [95% CI, 0.93-2.50]). Dyspnea relief was more frequent after CTO PCI (83% versus 65%, P=0.005), with no significant difference in angina.

CONCLUSIONS

This 10-year follow-up of patients post-ST-segment-elevation myocardial infarction randomized to CTO PCI or no-CTO PCI demonstrated no clinical benefit of CTO PCI in major adverse cardiac events or overall mortality. However, CTO PCI was associated with a higher cardiovascular mortality compared with no-CTO PCI. Our long-term data support a careful weighing of effective symptom relief against an elevated cardiovascular mortality risk in CTO PCI decisions.

REGISTRATION

URL: https://www.trialregister.nl; Unique identifier: NTR1108.

Coronary Artery Bypass Grafting versus Percutaneous Coronary Intervention in Patients with Chronic Total Occlusion

OBJECTIVES

 Mechanisms of coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) differ as CABG provides surgical collateralization and may prolong life by preventing future myocardial infarctions (MIs). However, evidence for CABG in patients with chronic total occlusion (CTO) has not been fully elucidated and the impact of PCI is discussed controversially.

METHODS

 We performed a meta-analysis of studies comparing outcomes in patients with/without multivessel disease undergoing CABG or PCI for CTO. The primary outcome was long-term all-cause mortality (≥5 years). Secondary outcomes were MIs, repeat revascularization, cardiac mortality, major adverse cardiovascular events, and stroke, as well as short-term mortality (30 days/in-hospital) and stroke. A pooled Kaplan-Meier survival curve after reconstruction analysis was generated. Random-effects models were used.

RESULTS

 Six studies totaling 12,504 patients were included. In the pooled Kaplan-Meier analysis, PCI showed a significantly higher risk of death in the follow-up compared with CABG (hazard ratio [HR]: 2.12, 95% confidence interval [CI]: 1.88-2.38, p < 0.01). During the observation period, PCI was also associated with higher rates of MI (odds ratio [OR]: 2.86, 95% CI: 1.82-4.48, p < 0.01) and more repeat revascularization (OR: 4.88, 95% CI: 1.99-11.91, p = 0.0005). The other outcomes did not show significant differences.

CONCLUSION

 CABG is associated with superior survival to PCI over time in patients with CTO who are eligible for both PCI and CABG. This survival advantage is associated with fewer events of MI and repeat revascularization.

Percutaneous Coronary Intervention versus Optimal Medical Therapy in Patients with Chronic Total Occlusion: A Meta-Analysis

Background/Objectives: Chronic total occlusion (CTO) is a prevalent finding in patients with coronary artery disease and is associated with increased mortality. Prior reports on the efficacy of percutaneous coronary intervention (PCI) compared to optimal medical therapy (OMT) were controversial. Following the emergence of recently published new evidence, a meta-analysis is warranted. The current meta-analysis assessed the effects of PCI compared to OMT in the treatment of CTO. Methods: A structured literature search was performed. Randomized controlled trials (RCTs) and non-randomized controlled studies of interventions were eligible. The primary outcome was an accumulated composite of cardiac mortality, myocardial infarction and target vessel/lesion revascularization events. Results: Thirty-two studies reporting on 11260 patients were included. Of these, 5712 (50.7%) were assigned to the PCI and 5548 (49.3%) were allocated to the OMT group. The primary outcome occurred in 14.6% of the PCI and 20.1% of the OMT group (12 trials, OR 0.66, 95% CI 0.50 to 0.88, p = 0.005, I2 = 67%). Subgrouping demonstrated a consistent reduction in the primary outcome for the PCI group in RCTs (six trials, OR 0.58, 95% CI 0.33 to 0.99, p = 0.05). The primary outcome reduction was irrespective of the study design, and it was replicable in sensitivity and subgroup analyses. Advantages in other outcomes were rather related to statistical pooling effects and dominated by observational data. Conclusions: CTO-PCI was associated with improved patient-oriented primary outcome compared to OMT in a study-level meta-analysis. This composite outcome effect was mainly driven by target vessel treatment, but a significant reduction in mortality and myocardial infarction was observed, irrespectively. These findings have hypothesis-generating implications. Future RCTs with adequate statistical power are eagerly awaited.

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.

Radiomics-based discrimination of coronary chronic total occlusion and subtotal occlusion on coronary computed tomography angiography

OBJECTIVES

Differentiating chronic total occlusion (CTO) from subtotal occlusion (SO) is often difficult to make from coronary computed tomography angiography (CCTA). We developed a CCTA-based radiomics model to differentiate CTO and SO.

METHODS

A total of 66 patients with SO underwent CCTA before invasive angiography and were matched to 66 patients with CTO. Comprehensive imaging analysis was conducted for all lesioned vessels, involving the automatic identification of the lumen within the occluded segment and extraction of 1,904 radiomics features. Radiomics models were then constructed to assess the discriminative value of these features in distinguishing CTO from SO. External validation of the model was performed using data from another medical center.

RESULTS

Compared to SO patients, CTO patients had more blunt stumps (internal: 53/66 (80.3%) vs. 39/66 (59.1%); external: 36/50 (72.0%) vs. 20/50 (40.0%), both p < 0.01), longer lesion length (internal: median length 15.4 mm[IQR: 10.4-22.3 mm] vs. 8.7 mm[IQR: 4.9-12.6 mm]; external:11.8 mm[IQR: 6.1-23.4 mm] vs. 6.2 mm[IQR: 3.5-9.1 mm]; both p < 0.001). Sixteen unique radiomics features were identified after the least absolute shrinkage and selection operator regression. When added to the combined model including imaging features, radiomics features provided increased value for distinguishing CTO from SO (AUC, internal: 0.772 vs. 0.846; p = 0.023; external: 0.718 vs. 0.781, p = 0.146).

CONCLUSIONS

The occluded segment vessels of CTO and SO have different radiomics signatures. The combined application of radiomics features and imaging features based on CCTA extraction can enhance diagnostic confidence.

Acute myocardial infarction complicated by cardiogenic shock in Ukraine: multicentre registry analysis 2021-2022

Background

Data on the results and management strategies in patients with acute myocardial infarction complicated by cardiogenic shock (AMI-CS) in the Low and Lower-Middle Income Countries (LLMICs) are limited. This lack of understanding of the situation partially hinders the development of effective cardiogenic shock treatment programs in this part of the world.

Materials and methods

The Ukrainian Multicentre Cardiogenic Shock Registry was analyzed, covering patient data from 2021 to 2022 in 6 major Ukrainian reperfusion centres from different parts of the country. Analysis was focusing on outcomes, therapeutic modalities and mortality predictors in AMI-CS patients.

Results

We analyzed data from 221 consecutive patients with CS from 6 hospitals across Ukraine. The causes of CS were ST-elevated myocardial infarction (85.1%), non-ST-elevated myocardial infarction (5.9%), decompensated chronic heart failure (7.7%) and arrhythmia (1.3%), with a total in-hospital mortality rate for CS of 57.1%. The prevalence of CS was 6.3% of all AMI with reperfusion rate of 90.5% for AMI-CS. In 23.5% of cases, CS developed in the hospital after admission. Mechanical circulatory support (MCS) utilization was 19.9% using intra-aortic balloon pump alone. Left main stem occlusion, reperfusion deterioration, Charlson Comorbidity Index >4, and cardiac arrest were found to be independent predictors for hospital mortality in AMI-СS.

Conclusions

Despite the wide adoption of primary percutaneous coronary intervention as the main reperfusion strategy for AMI, СS remains a significant problem in LLMICs, associated with high in-hospital mortality. There is an unmet need for the development and implementation of a nationwide protocol for CS management and the creation of reference CS centers based on the country-wide reperfusion network, equipped with modern technologies for MCS.