A New Algorithm for Crossing Chronic Total Occlusions From the Asia Pacific Chronic Total Occlusion Club

Outcomes of Percutaneous Coronary Intervention for Chronic Total Occlusion With Bifurcation at Distal Cap

BACKGROUND

Bifurcation at the chronic total occlusion (CTO) distal cap is a key factor in the global CTO crossing algorithm.

OBJECTIVES

This study was performed to analyze procedural outcomes and adverse events and to evaluate strategies for managing bifurcation at the CTO distal cap.

METHODS

We analyzed 11,627 patients enrolled in the Japanese CTO-PCI Expert Registry with an analyzable CTO distal cap between January 2014 and December 2022.

RESULTS

A bifurcation lesion at the distal cap was present in 21.2% (n = 2,462 of 11,627) of all CTO lesions. The retrograde approach was used more frequently in cases with than without bifurcation (45.1% [n = 1,111 of 2,462] vs 40.5% [n = 3,716 of 9,165]; P < 0.001). Analyzing each of the 3 major coronary vessels, the distal cap bifurcation group more frequently required the retrograde approach in the right coronary artery (57.7% [n = 653 of 1,131] vs 49.4% [n = 2,297 of 4,648]; P < 0.001) and the left circumflex artery (28.4% [n = 141 of 497] vs 23.7% [n = 367 of 1,546]; P = 0.044). There were no significant differences in guidewire success, technical success, or procedural success rates between the two groups. However, the bifurcation group required a longer procedure time, used more contrast volume, and had a longer fluoroscopy time than the no bifurcation group.

CONCLUSIONS

Although there are concerns about the success rate when a bifurcation is present distal to the CTO, it has been shown that the combined use of the retrograde approach can achieve a high success rate equivalent to that of lesions without bifurcations.

Dissection Techniques in Chronic Total Occlusion Percutaneous Coronary Intervention

BACKGROUND

There is limited data on dissection strategies in chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

AIMS

To study the differences in the baseline characteristics and procedural outcomes of antegrade CTO PCIs that used dissection strategies.

METHODS

We performed a comparative analysis of antegrade dissection and re-entry CTO PCIs from the PROGRESS-CTO registry from 50 centers (2012-2024). Three dissection strategies were compared: (a) knuckle wiring: knuckle wire(s) without Carlino technique or CrossBoss catheter; (b) the CrossBoss technique: use of the CrossBoss catheter; and (c) the Carlino technique: use of the Carlino technique. In-stent CTO PCIs were excluded from the analysis.

RESULTS

In total, 1575 (74.6%) cases used knuckle wiring, 427 (20.2%) the CrossBoss, and 110 (5.2%) the Carlino technique. Knuckle wiring was the most frequent strategy with increasing utilization over time (p < 0.001). The CrossBoss catheter was more common in lesions with lower J-CTO scores (CrossBoss: 2.91 vs. Knuckle wiring: 3.07 vs. Carlino: 3.18; p = 0.015), and was associated with higher technical success (CrossBoss: 84.0% vs. Knuckle wiring: 74.2% vs. Carlino: 64.2%; p < 0.001) and similar major adverse cardiac events rates, but lower perforation rates. Time to crossing was longer when Carlino was used (CrossBoss: 93 [70, 133] min vs. Knuckle wiring: 97 [63, 136] min vs. Carlino: 133 [84, 166] min, p = 0.001). Use of different types of knuckle wires (Pilot 200, Gladius Mongo, and Fielder XT) was associated with similar success rates.

CONCLUSIONS

Knuckle wiring is the most commonly used antegrade dissection strategy. The CrossBoss catheter was used in less complex cases and was associated with higher success, whereas the opposite was true for the Carlino technique.

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.

Machine Learning-Based Algorithm to Predict Procedural Success in a Large European Cohort of Hybrid Chronic Total Occlusion Percutaneous Coronary Interventions

CTOs are frequently encountered in patients undergoing invasive coronary angiography. Even though technical progress in CTO-PCI and enhanced skills of dedicated operators have led to substantial procedural improvement, the success of the intervention is still lower than in non-CTO PCI. Moreover, the scores developed to appraise lesion complexity and predict procedural outcomes have shown suboptimal discriminatory performance when applied to unselected cohorts. Accordingly, we sought to develop a machine learning (ML)-based model integrating clinical and angiographic characteristics to predict procedural success of chronic total occlusion (CTO)-percutaneous coronary intervention(PCI). Different ML-models were trained on a European multicenter cohort of 8904 patients undergoing attempted CTO-PCI according to the hybrid algorithm (randomly divided into a training set [75%] and a test set [25%]). Sixteen clinical and 16 angiographic variables routinely assessed were used to inform the models; procedural volume of each center was also considered together with 3 angiographic complexity scores (namely, J-CTO, PROGRESS-CTO and RECHARGE scores). The area under the curve (AUC) of the receiver operating characteristic curve was employed, as metric score. The performance of the model was also compared with that of 3 existing complexity scores. The best selected ML-model (Light Gradient Boosting Machine [LightGBM]) for procedural success prediction showed an AUC of 0.82 and 0.73 in the training and test set, respectively. The accuracy of the ML-based model outperformed those of the conventional scores (J-CTO AUC 0.66, PROGRESS-CTO AUC 0.62, RECHARGE AUC 0.64, p-value <0.01 for all the pairwise comparisons). In conclusion, the implementation of a ML-based model to predict procedural success in CTO-PCIs showed good prediction accuracy, thus potentially providing new elements for a tailored management. Prospective validation studies should be conducted in real-world settings, integrating ML-based model into operator decision-making processes in order to validate this new approach.

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.

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.

Improvement of Radiation Management in Percutaneous Interventions of Chronic Total Occlusions in a Multicenter Registry

BACKGROUND

Excess radiation exposure is a limiting factor in percutaneous coronary intervention (PCI) for chronic total coronary occlusion (CTO).

OBJECTIVES

The aim of this study was to analyze changes in radiation dose for CTO PCI with increasing risk awareness during the past decade and the determinants of these changes.

METHODS

A total of 16,439 procedures performed by 14 operators continuously participating in the European Registry of CTO-PCI from 2012 to 2023 were analyzed. Changes in air kerma (AK) were assessed, and a dose rate index (DRI) was calculated as AK per fluoroscopy time (FT).

RESULTS

Lesion complexity increased from a median J-CTO (Multicenter CTO Registry in Japan) score of 2 (Q1-Q3: 1-3) to 3 (Q1-Q3: 2-3) (P < 0.001), and technical success improved from 89.1% to 94.9% (P < 0.001), with stable FT. AK decreased from 2.50 Gy (Q1-Q3: 1.54-4.04 Gy) to 1.20 Gy (Q1-Q3: 0.66-2.12 Gy), a reduction of 52.0% (P < 0.001). Excess radiation of AK >5 Gy was reduced from 15.8% in 2012-2013 to 3.7% in 2022-2023. Clinical determinants of excess radiation were body mass index, gender, and previous bypass surgery; procedural determinants were FT, retrograde approach, and intravascular ultrasound use; and equipment determinants were radiographic equipment updates and fluoroscopy dose mode. Operators reduced DRI by 21.7% from 62.6 mGy/min (Q1-Q3: 44.7-89.3 mGy/min) to 49.0 mGy/min (Q1-Q3: 35.4-71.2 mGy/min) before a radiographic equipment update; after the update, DRI was further reduced to 31.5 mGy/min (Q1-Q3: 22.0-45.6 mGy/min), a decrease of 28.0% (P < 0.001) The interoperator comparison of DRI indicated considerable variability in radiation management.

CONCLUSIONS

AK for CTO PCI was reduced during the past decade to a level such that most procedures no longer must be aborted because of excess radiation. Equipment updates were instrumental, but interoperator differences remained.

New Frontiers in Antegrade Wiring From the Asia Pacific Chronic Total Occlusion Club

Antegrade wiring (AW) is the prevailing chronic total occlusion (CTO) crossing technique. For proximal cap ambiguity, the Global CTO consensus group uses the "anatomy dictates strategy" method: 1) intravascular ultrasound; 2) move the cap; or 3) retrograde. For CTO body crossing, anatomy dictates 4 strategies: 1) CTOs with tapered stump-loose tissue tracking; 2) CTOs with clear intimal path-intentional intimal tracking with 3-dimensional (3D) wiring; 3) CTOs without a clear intimal path-intentional intimal tracking with intermediate penetration wire; and 4) the "long plus CTOs"-intentional subintimal wiring. The new angiographic 3D antegrade puncture technique from the APCTO (Asia Pacific Chronic Total Occlusion) Club is presented for distal cap puncture. angiographic 3D antegrade puncture technique can be used as a 3D wiring technique as well as an antegrade dissection and re-entry technique. Based on these new frontiers, we have updated our APCTO algorithm in this paper. This update can form a basis for research and training.

Antegrade techniques for chronic total occlusion percutaneous coronary intervention

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

The efficacy of revascularization in ischemic cardiomyopathy

Ischemic cardiomyopathy (ICM) is characterized by myocardial dysfunction due to myocardial ischemia, associated with the presence of significant coronary artery disease (CAD). We provide a comprehensive review of the current evidence for coronary revascularization in ICM, including consideration of the different modalities of coronary artery bypass grafting and percutaneous coronary intervention. In addition to a contemporary assessment of the literature, we aim to provide real-world insights and perspectives to guide clinical decision-making in this heterogeneous and complex patient population.

Comparison between tip-detection method and retrograde approach for chronic total occlusion percutaneous coronary intervention

BACKGROUND

The tip-detection method and the retrograde approach have been acknowledged as a second-line strategies for chronic total occlusion (CTO) percutaneous coronary intervention (PCI) when conventional antegrade wiring strategies are ineffective. The aim of this study is to compare the efficacy between both strategies for complex CTO PCI.

METHODS

We retrospectively enrolled 170 consecutive CTO PCI cases and separated them into 295 adopted strategies. The rate of successful lesion crossing and its association with the time spent for each strategy were compared between the tip-detection method and the retrograde approach.

RESULTS

We observed fifty-six attempts with the tip-detection methods with 46 (82.1%) successful lesion crossings. Sixty-one retrograde approaches were performed, in which 29 (47.5%) cases achieved procedural success. In the successful attempts, the wire-manipulation time was significantly shorter in the tip-detection method [20.0 (12.2-36.7) min] than the retrograde approach [35.0 (20.7-49.7) min] (p = 0.008). Cox-regression analysis showed time-dependent advantage for the tip-detection method over the retrograde approach [hazard ratio (HR) = 2.93, 95% CI = 1.84-4.67, p < 0.001]. Incomplete tip-detection CTO crossing (taking > 30 min) was seen in severely tortuous lesions [odds ratio 0.26, 95% confidence interval 0.06-0.97, p = 0.037].

CONCLUSION

The tip-detection method can reduce the wire-manipulation time for successful CTO PCI compared with the retrograde approach. However, the success rate of the tip-detection method is hampered by severe lesion tortuosity.

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.

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.

Impact of aging on long-term cardiac outcomes of true-lumen recanalized chronic total occlusions in patients with overweight/obesity

BACKGROUND

Obesity paradox addressing all-cause mortality has been described in several chronic total occlusion (CTO) studies. However, the impact of aging on long-term cardiac events in patients with overweight and obesity with CTO recanalization were less studied.

METHODS

A total of 458 patients (64.4 ± 11.3 years, 403 male) with CTO interventions were enrolled. The overweight/obesity group included 311 patients with body mass index (BMI) ≧24 kg/m2 and the non-obesity group included 147. With a median follow-up of 40.0 (17.9-61.4) months, 422 patients with successful true-lumen recanalization were further assessed for target lesion failure [TLF: cardiac death, target vessel myocardial infarction (TVMI), target lesion revascularization (TLR)].

RESULTS

At follow-up, the rates of cardiac death, TVMI, TLR, TLF, and stent thrombosis were 1.9%, 1.9%, 9.2%, 10.7%, and 0.5%, respectively. The TVMI-free survival was borderline better (p = 0.067 by log-rank test) in overweight/obesity than non-obesity group. Among patients <65 years of age, the TVMI-free survival was significantly better in the overweight/obesity group (p = 0.013 compared to non-obesity group by log-rank test). In multivariate Cox regression model, the non-obesity patients younger than 65 years were at a higher risk of TVMI, not only among those <65 years of age (hazard ratio = 11.0, 95% CI = 1.1-106.0) but also among the whole patients (hazard ratio=6.9, 95% CI = 1.4-35.1) with successful CTO recanalization.

CONCLUSIONS

For those with true-lumen recanalized CTO, the higher risk of TVMI after successful recanalization was rather evident in patients <65 years of age and without overweight/obesity, suggesting that aging might attenuate prognostic significance of "obesity paradox" for CTO interventions.

Role of calcification in J-CTO score: a viewpoint of intraplaque guidewire tracking techniques

BACKGROUND

As the burden and distribution of calcification within chronic total occlusion (CTO) lesions can be diverse, its effect on CTO recanalization using multiple devices and techniques is debatable. This study investigated the role of calcification in wiring-based intraplaque tracking techniques for CTO recanalization.

METHODS

A modified J-CTO score without counting calcification was used to analyze the procedures of 458 consecutive patients who underwent CTO interventions. Failed guidewire crossing and intraplaque tracking were considered procedural failures. Recanalization time details were analyzed for successful procedures.

RESULTS

In patients with calcified CTO, the rate of procedural success only significantly declined to be lower than that of noncalcified CTO when the modified J-CTO score was ≥3 (77% vs. 94%, p = 0.008). In 422 patients with successful procedures, the presence of calcification was irrelevant to guidewire crossing time, but was accompanied with longer time from guidewire cross to final angiogram when the modified J-CTO score was 1-2 (53 ± 35 vs. 35 ± 17 [noncalcified] min, p < 0.001). Multivariate analyses showed that calcification was independently associated with procedural failure (odds ratio [OR] = 5.1, 95% confidence interval [CI] = 1.4-18.3) in lesions with modified J-CTO ≥3, and prolonged angioplasty/stenting procedures >60 min (OR = 4.8, 95% CI = 2.2-10.2) in successfully recanalized lesions with modified J-CTO score 1-2.

CONCLUSIONS

Using intraplaque guidewire tracking, calcification was unfavorable for very difficult CTO lesions, and caused prolongation of angioplasty time for lesions with moderate complexity. This suggested that the role of calcification in the J-CTO score could be altered when different recanalization techniques were applied for CTO interventions.

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.

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.

Mechanisms of Medial Wall Thinning in Chronic Total Occlusion

BACKGROUND

The success rate of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) is lower and the risk for complications higher compared with other non-CTO PCI. Although interventionalists focus on intimal plaque characteristics, the coronary media is an important (especially for techniques involving antegrade dissection and re-entry) but poorly understood structure in CTO PCI.

OBJECTIVES

The aim of the present study was to investigate coronary medial wall thinning in CTO lesions and determine how this thinning might affect CTO PCI.

METHODS

A total of 2,586 sections were investigated, from arteries with evidence of CTO from 54 subjects (1,383 sections) and arteries without evidence of CTO from 54 subjects with non-coronary-related deaths (1,203 sections) after matching for age, gender, body weight, and body height.

RESULTS

The medial thickness in subjects with CTO was lower than that in those with non-coronary-related death (P < 0.001). In subjects with CTO, CTO lesions had thinner medial walls compared with those with lower luminal narrowing (P < 0.001). At the CTO distal segments, the 6- to 12-mm distal segment from the distal end of the CTO had significantly less luminal narrowing (P < 0.001), and similar medial thickness, compared with the distal end of the CTO. Immunohistochemical analysis revealed that short-duration CTO had more cleaved caspase-3-positive cells in media and had significantly more CD3+, CD4+, CD8+, and CD4+CD28null T cells compared with long-duration CTO.

CONCLUSIONS

CTO lesions demonstrated coronary medial thinning compared with non-CTO lesions. Further investigation of the cause-and-effect relationship among inflammation, apoptosis, and coronary medial wall thinning is warranted in future mechanistic studies.

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.

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.

Tip Detection-Antegrade Dissection and Re-Entry With New Puncture Wire in CTO Intervention: Revolution Through 3D-Wiring

Background

The authors devised the tip detection (TD) method and developed AnteOwl WR intravascular ultrasound to standardize intravascular ultrasound-based 3-dimensional wiring for intraplaque tracking in chronic total occlusion (CTO)-percutaneous coronary intervention (PCI). The TD method also allowed antegrade dissection and re-entry (ADR). Combining TD-ADR with Conquest Pro 12 Sharpened Tip (CP12ST) wire, a new ADR wire with the strongest penetration force developed to date, enabled re-entry anywhere except calcification sites.

Objectives

This study investigated the efficacy and feasibility of TD-ADR by comparison of procedural outcomes with Stingray-ADR in CTO-PCI.

Methods

Twenty-seven consecutive CTO cases treated by TD-ADR with CP12ST wire between August 2021 and April 2023 and 27 consecutive CTO cases treated by Stingray-ADR with Conquest 8-20 (CP20) wire between March 2018 and July 2021 were retrospectively enrolled as the TD-ADR by CP12ST wire group and Stingray-ADR by CP20 wire group, respectively, from 4 facilities that could share technical information on these procedures.

Results

The success rate of the ADR procedure was significantly improved (27 of 27 cases [100%] vs 18 of 27 cases [67%], respectively; P = 0.002) and total procedural time was significantly reduced (median procedural time: 145.0 [Q1-Q3: 118.0-240.0] minutes vs 185.0 [Q1-Q3: 159.5-248.0] minutes, respectively; P = 0.028) in the TD-ADR by CP12ST wire group compared to the Stingray-ADR by CP20 wire group. There were few in-hospital major adverse cardiac and cerebrovascular events or no complications in either group.

Conclusions

TD-ADR by CP12ST wire can standardize highly accurate ADR in CTO-PCI.

The Characteristics of Primary Retrograde Approach Selection for Native Coronary Chronic Occlusion With Short Occlusion Length from the Japanese CTO-PCI Expert Registry

Although the coronary chronic total occlusion (CTO) crossing algorithm has been published, the characteristics associated with the first strategy selection for short-length lesions <20 mm is still debatable. This study aimed to determine the characteristics associated with primary retrograde approach (PRA) for native CTO with short occlusion length in percutaneous coronary intervention (PCI). Between January 2014 and December 2021, we examined data on 4,088 lesions in the Japanese CTO-PCI Expert Registry with occlusion lengths <20 mm. Then, the characteristics for short-length CTO, which was performed by way of the PRA, were assessed. PRA was performed in 785 patients (19.2%). The guidewire success rate was 93.6%, and the technical success rate was 91.3%. Previous coronary artery bypass grafting, chronic kidney disease, and 6 lesion/anatomic characteristics (i.e., blunt stump, distal runoff <1 mm, CTO lesion tortuosity, reattempt procedures, ostial location, and the presence of collateral channel grade 2) were associated with PRA (p <0.05). Moreover, hemodialysis was an independent factor of unsuccessful anterograde guidewire crossing, along with distal runoff <1 mm, the existence of calcification, and CTO lesion tortuosity (all p <0.05). In clinical settings, these independent factors for PRA in short-length CTO can help in selecting the CTO-PCI strategy.

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.

Comparative Analysis of Polymer Versus Non-Polymer Jacketed Wires in Chronic Total Occlusion Percutaneous Coronary Intervention

There is significant variation in wire utilization patterns for chronic total occlusion (CTO) percutaneous coronary intervention. This study aimed to compare the outcomes of polymer-jacketed wires (PJWs) versus non-PJWs in anterograde procedures. We analyzed clinical and angiographic characteristics, and procedural outcomes of 7,575 anterograde CTO percutaneous coronary interventions that were performed at 47 centers between 2012 and 2023. Cases in which PJWs were exclusively used were classified in the PJW group, whereas cases where at least one non-PJW was employed were classified in the non-PJW group. Study end points were as follows: technical success, coronary perforation, major adverse cardiac event. PJWs were exclusively used in 3,481 cases (46.0%). These cases had lower prevalence of proximal cap ambiguity, blunt stump, and moderate/severe calcification. They also had lower Japanese CTO (J-CTO), Prospective Global Registry for the Study of Chronic Total Occlusion (PROGRESS-CTO), and PROGRESS-CTO complications scores, higher technical success (94.3% vs 85.7%, p <0.001), and lower perforation rates (2.2% vs 3.2%, p = 0.013). Major adverse cardiac event rates did not differ between groups (1.3% vs 1.5%, p = 0.53). Exclusive use of PJWs was independently associated with higher technical success in both the multivariable (odds ratio [OR] 2.66, 95% confidence interval [CI] 2.13 to 3.36, p <0.001) and inverse probability of treatment weight analysis (OR 2.43, 95% CI 2.04 to 2.89, p <0.001). Exclusive use of PJWs was associated with lower risk of perforation in the multivariable analysis (OR 0.69, 95% CI 0.49 to 0.95, p = 0.02), and showed a similar trend in the inverse probability of treatment weight analysis (OR 0.77, 95% CI 0.57 to 1.04, p = 0.09). Exclusive use of PJWs is associated with higher technical success and lower perforation risk in this non-randomized series of patients.

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.

Coronary chronic total occlusion on coronary CT angiography: what radiologists should know?

Coronary chronic total occlusion (CTO) often occurs in patients with obstructive coronary artery disease, which remains one of the greatest challenges for interventional cardiologists. Coronary computed tomography angiography (CCTA) with its emerging post-processing techniques can provide a detailed assessment of CTO lesions before percutaneous coronary intervention (PCI), playing an important role in the clinical management of CTO PCI, from early diagnosis, pre-procedural outcome prediction, the crossing algorithm planning, intraprocedural guidance, and finally post-procedural assessment and follow-up. In addition, the feasibility of CT perfusion (CTP) in patients with CTO has been validated. Combined CCTA and CTP have the great potential to be the one-stop-shop imaging modality for assessing both anatomy and function of CTO lesions. This review aims to make radiologists understand the role of CCTA in the diagnosis and assessment of CTO lesions, thus assisting interventionalists in optimizing CTO PCI crossing strategies with the expertise of radiologists.Critical relevance statement The anatomical features of CTO on CCTA can reveal the complexity of CTO lesions and are associated with CTO PCI outcome, thus helping interventionalists optimize CTO PCI crossing strategies.Key points • CTO is the common lesion in invasive coronary angiography, and CTO PCI is technically difficult and its success rate is relatively low.• Length, collaterals, and attenuation-related signs can help distinguish CTO from subtotal occlusion.• The anatomical features of CTO lesions can help grade the difficulty of CTO PCI and predict procedural outcomes and long-term outcomes of CTO PCI.• The real-time fusion of CCTA with fluoroscopic angiography can be applied in highly complicated CTO lesions.• After CTO PCI, CCTA can help guide a second CTO PCI re-entry or follow up stent patency.

Determinants of successful parallel wire technique in percutaneous coronary intervention to coronary chronic total occlusion

BACKGROUND

Many techniques and concepts have been developed in the field of percutaneous coronary intervention to chronic total occlusion (CTO). Parallel wire technique (PWT) is still an important technique in antegrade approach. The purpose of this study was to identify the determinants of successful PWT in coronary CTO.

METHODS

We reviewed consecutive 451 CTO lesions that were treated with PCI in our medical center. The overall success rate of PCI to CTO during the study period was 92.2 % (416/451). Of 451 CTO lesions, we excluded 333 CTO lesions in which PTW was not performed. We included 118 CTO lesions in which PWT was performed, and divided them into the successful PWT group (n = 65) and the unsuccessful PWT group (n = 53) according to the procedure success of PWT. Multivariate logistic regression analysis were performed to find the determinants of successful PWT.

RESULTS

The prevalence of the sufficient clarity of CTO exit site was significantly higher in the successful PWT group (46.2 %) than in the unsuccessful PWT group (11.3 %) (p < 0.01). Multivariate logistic regression analysis revealed that the J-CTO score was inversely associated with successful PWT (OR 0.66, 95 % CI 0.44-0.99, P = 0.04), whereas the sufficient clarity of CTO exit site was associated with successful PWT (OR 5.16, 95 % CI 1.75-15.20, P < 0.01).

CONCLUSIONS

The J-CTO score was inversely associated with successful PWT, whereas the sufficient clarity of CTO exit site was associated with successful PWT. The low J-CTO score and the sufficient clarity of CTO exit site may be the determinants of successful PWT.

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.

Short- and Long-term Outcomes of Percutaneous Coronary Interventions in Chronic and Non-chronic Total Occlusions: A Meta-analysis of 690,123 Patients

The use of percutaneous coronary intervention (PCI) in patients with chronic total occlusion (CTO) is still a subject of debate, with conflicting outcomes reported in different studies when compared to non-CTO lesions. This meta-analysis aims to clarify the clinical outcomes of PCI in CTO cases compared to non-CTO lesions, both in the short and long-term. PubMed, Scopus, Web of Science, Ovid, and Cochrane Central were searched until March 2023 for relevant studies addressing short- and long-term outcomes of PCI in CTO vs non-CTO lesions. Dichotomous data were pooled as odds ratio (OR) with its 95% confidence interval (CI) in a random Der-Simonian lair effect model using STATA 17 MP. Eight studies with a total of 690,123 patients were included. In terms of short-term outcomes, CTO PCI was associated with higher rates of vessel perforation (OR = 2.16, 95% CI: 1.31-3.57) and cardiac tamponade (OR = 5.19, 95% CI: 4.29-6.28). Additionally, CTO PCI showed lower rates of procedural success (OR = 0.84, 95% CI: 0.73-0.96). Moreover, in the long-term, CTO PCI had higher rates of MACE (OR = 1.02, 95% CI: 1.01-1.04), however, it showed lower rates of cardiac death (OR = 0.61, 95% CI: 0.38-0.98), with no significant difference in other reported outcomes. Our findings underscore the challenges and adverse outcomes associated with using PCI to treat CTO lesions in the short term. This suggests that interventional cardiologists should carefully evaluate the risks and benefits before proceeding with PCI in CTO lesions.

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.

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.

Impact of minimum contrast media volumes during percutaneous coronary intervention for chronic total occlusion lesion

Contrast media exposure is associated with contrast-induced nephropathy (CIN) following percutaneous coronary intervention (PCI) of chronic total occlusion (CTO). Aim of this study is to assess the utility of minimum contrast media volume (CMV ≤ 50 mL) during CTO-PCI for CIN prevention in patients with chronic kidney disease (CKD). We extracted data from the Japanese CTO-PCI expert registry; 2863 patients with CKD who underwent CTO-PCI performed from 2014 to 2020 were divided into two groups: minimum CMV (n = 191) and non-minimum CMV groups (n = 2672). CIN was defined as an increased serum creatinine level of ≥ 25% and/or ≥ 0.5 mg/dL compared with baseline levels within 72 h of the procedure. In the minimum CMV group, the CIN incidence was lower than that in the non-minimum CMV group (1.0% vs. 4.1%; p = 0.03). Patient success rate was higher and complication rate was lower in the minimum CMV group than in the non-minimum CMV group (96.8% vs. 90.3%; p = 0.02 and 3.1% vs. 7.1%; p = 0.03). In the minimum CMV group, the primary retrograde approach was more frequent in the case of J-CTO = 1,2 and 3-5 groups compared to that in non-minimum CMV-PCI group (J-CTO = 0; 11% vs. 17.7%, p = 0.06; J-CTO = 1; 22% vs. 35.8%, p = 0.01; J-CTO = 2; 32.4% vs. 46.5%, p = 0.01; and J-CTO = 3-5; 44.7% vs. 80.0%, p = 0.02). Minimum CMV-PCI for CTO in CKD patients could reduce the incidence of CIN. The primary retrograde approach was observed to a greater extent in the minimum CMV group, especially in cases of difficult CTO.

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.

Clinical effective use of Conquest Pro 12 Sharpened Tip for chronic total occlusion intervention: A series of three case reports

A new chronic total occlusion (CTO) guidewire, Conquest Pro 12 Sharpened Tip (CP12ST), has a stronger penetration force than the original CP12 and a deflection effect that it does not have. The CP12ST enables us to advance into hard plaque that has not ever penetrated, which might change CTO treatment as shown in three cases.

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.

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.

Impact of percutaneous coronary intervention on chronic total occlusion in the non-infarct-related artery in patients with STEMI: a systematic review and meta-analysis

OBJECTIVES

We sought to compare the clinical outcomes between culprit-only percutaneous coronary intervention (PCI) versus multivessel PCI (MV-PCI) in patients with ST-segment elevation myocardial infarction (STEMI) accompanied by chronic total occlusion (CTO) in the non-infarct-related artery(non-IRA).

DESIGN

Studies that compared culprit-only PCI versus MV-PCI in patients with STEMI accompanied by CTO in the non-IRA were included. Random odds ratio (OR) and 95% confidence interval (CI) were calculated.

RESULTS

Eight studies with 2,259 patients were included. The results suggested that in patients with STEMI accompanied by CTO in the non-IRA, culprit-only PCI was associated with higher risks of all-cause mortality (OR: 2.89; 95% CI: 2.09-4.00; I² = 0.0%), cardiac death (OR: 3.12; 95% CI: 2.05-4.75; I² = 16.8%), stroke (OR: 2.80; 95% CI: 1.04-7.53; I² = 0.0%), major adverse cardiovascular event (MACE; OR: 2.06; 95% CI: 1.39-3.06; I² = 54.0%), and heart failure (OR: 1.99; 95% CI: 1.22-3.24; I² = 0.0%) compared with staged MV-PCI, which were mainly derived from retrospective studies. No differences were observed in myocardial infarction or revascularization. Pooled multivariable adjusted results consistently indicated that staged MV-PCI was superior to culprit-only PCI.

CONCLUSIONS

For patients with STEMI accompanied by CTO in the non-IRA, staged MV-PCI may be better compared with culprit-only PCI due to potential reduced risks of all-cause mortality, cardiac death, stroke, MACE, and heart failure. Meanwhile, further randomized trials are warranted to confirm or refute our findings.

Operator experience and clinical outcomes of percutaneous coronary intervention for chronic total occlusion: insights from a pooled analysis of the Japanese CTO PCI Expert Registry and the Retrograde Summit General Registry

There have not been enough studies to examine the association between difference in operator experience and technical success rate in contemporary percutaneous coronary intervention for chronic total occlusion (CTO-PCI). The present study sought to provide insights into the impact of operator experience on clinical outcomes of CTO-PCI through a comparison of two largest Japanese CTO-PCI registries consisting of operators with different CTO-PCI experience. After combining clinical data from the Japanese CTO-PCI Expert Registry (ER) 2014-2016 (N = 4316) including CTO-PCI performed by highly experienced operators and the Retrograde Summit General Registry (RSGR) 2014-2016 (N = 2230) including CTO-PCI performed by less experienced operators, a pooled analysis was performed to compare clinical outcomes of CTO-PCI in 2 registries. The overall technical success rate and the incidence of in-hospital major adverse events were comparable between ER and RSGR (90.1% vs 88.9%, p = 0.133, 1.7% vs 1.5%, p = 0.606, respectively). Technical success rate in ER was significantly higher among the patients treated with primary antegrade approach (91.8% vs 89.5%, p = 0.009), whereas there was no significant difference among the patients treated with the primary retrograde approach (85.7% vs 85.3%, p = 0.857). Multivariate analysis suggested ER operator could not be an independent predictor for technical success. CTO-PCI performed by less experienced but appropriately trained operators could achieve similarly high technical success rate with comparable safety compared with those performed by highly experienced specialists in contemporary Japanese context.

Extraplaque versus intraplaque tracking in chronic total occlusion percutaneous coronary intervention

OBJECTIVE

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Recanalisation of coronary chronic total occlusions

Percutaneous treatment of coronary chronic total occlusions (CTO) has advanced greatly since its advent in the late 1970s through the development of dedicated wires and microcatheters, the improved skills of highly experienced operators and the adoption of new sophisticated strategies to guide procedural planning. The contemporary procedural success rate is 80-90% with a reduction in complications. Although there has been no improvement in prognosis in randomised trials to date, they, and other controlled registries of thousands of patients, confirm the pivotal role of CTO recanalisation in the treatment of angina and dyspnoea and an improvement in quality of life. Despite this evidence, CTO recanalisation is grossly underutilised. This review reports a detailed overview of the history, indications and treatment strategies for CTO recanalisation and hopes to increase interest among new, and especially young, operators in this demanding, rapidly evolving field of interventional cardiology.

Predictive performance of J-Calc-CTO score for guidewire crossing through chronic total occlusion lesions within 30 minutes: J-CTO score modified by computed tomography coronary angiography

The original J-CTO score predicts the difficulty of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) lesions, but the grade of calcification has not been fully evaluated. We examined 137 patients (141 CTO lesions) who underwent coronary computed tomography angiography (CTA) pre-PCI between October 2016 and October 2021. They were randomly divided into derivation (n = 94) and validation (n = 47) groups. The degree and distribution of calcification in the occluded segment were assessed using CTA. The calcified index was defined as calcium volume divided by the length of the occluded segment. We created the J-Calc-CTO score consisting of calcification parameters associated with 30-min wire crossing in the derivation group. The validity of the J-Calc-CTO score was compared with that of the original J-CTO score using c-statistics. The procedural success rate was 96%, and 30-min wire crossing during the procedure was achieved in 29%. Dense calcification (calcified-index >12) (odds ratio [OR]: 4.63; 95% confidence interval [CI]: 1.24-22.2; p = 0.04) and calcification in the center of the lumen (OR: 7.25; 95% CI: 1.48-32.1; p = 0.02) were independently associated with 30-min wire crossing as variables evaluated using CTA. The J-Calc-CTO score was created by adding 1 point to the two parameters in place of "calcification" in the original J-CTO score. The J-Calc-CTO score showed a higher predictive value of 30-min wire crossing than the J-CTO score in the derivation (c-statistics; 0.836 vs. 0.670; p > 0.01) and validation groups (c-statistics; 0.879 vs. 0.767, p > 0.01). The degree and distribution of calcification evaluated using CTA refined the predictive value of the original J-CTO score for 30-min wire crossing.

Use of intravascular ultrasound for optimal vessel sizing in chronic total occlusion percutaneous coronary intervention

Aim

The aim of this study is to provide evidence on how use of standardized intravascular ultrasound (IVUS) use impacts stent size choice in the setting of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) compared to visual estimation.

Methods and results

Data of 82 consecutive patients who had successfully undergone IVUS-guided revascularization of CTO at the University Medical Center Mainz were analyzed. Angiography-based stent size prediction for the proximal and distal vessels was compared to the implanted stent diameter after IVUS assessment. Angiography-based stent size prediction for the proximal vessel was 3.09 ± 0.41, whereas IVUS use demonstrated larger vessel diameter, resulting in larger implanted stent diameter (3.24 ± 0.45, p &lt; 0.001). Proximal vessel stent size prediction was underestimated in the majority of patients by angiographic estimation. Angiography-based stent size prediction for the distal vessel was 2.79 ± 0.38, whereas IVUS use demonstrated larger vessel diameter, resulting in larger implanted stent diameter (2.92 ± 0.39, p &lt; 0.001).

Conclusion

Pre-stent IVUS assessment in CTO PCI provides important information on vessel morphology and size. Angiography-based stent size prediction for the proximal and distal vessels was frequently underestimated, IVUS use demonstrated larger vessel diameter, resulting in significantly larger implanted stent diameter.

Antegrade dissection and re-entry versus parallel wiring in chronic total occlusion percutaneous coronary intervention: Insights from the PROGRESS-CTO registry

BACKGROUND

The comparative efficacy and safety of parallel wiring versus antegrade dissection and re-entry (ADR) in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is controversial.

METHODS

We compared the clinical and angiographic characteristics and outcomes of parallel wiring versus ADR after failed antegrade wiring in a large, multicenter CTO PCI registry.

RESULTS

A total of 1725 CTO PCI procedures with failed antegrade wiring with a single wire were approached with parallel wiring (692) or ADR (1033) at the discretion of the operator. ADR patients were older (65 ± 10 vs. 62 ± 10, years, p < 0.001) and had higher prevalence of comorbidities, such as diabetes mellitus (43% vs. 32%, p < 0.001), prior coronary artery bypass graft surgery (31% vs. 19%, p < 0.001), and lower left ventricular ejection fraction (50 ± 14 vs. 53 ± 11%, p < 0.001). The ADR group had higher J-CTO (2.8 ± 1.1 vs. 2.1 ± 1.3, p < 0.001) and PROGRESS-CTO (1.6 ± 1.1 vs. 1.2 ± 1.0, p < 0.001) scores. Equipment use including guidewires, balloons, and microcatheters was higher, and the procedures lasted longer in the ADR group. Technical success (78% vs. 75%, p = 0.046) and major adverse cardiovascular events (composite of all-cause mortality, stroke, acute myocardial infarction, emergency surgery or re-PCI, and pericardiocentesis) (3.7% vs. 1.9%, p = 0.029) were higher in the ADR group, with similar procedural success (75% vs. 73%, p = 0.166).

CONCLUSION

In lesions that could not be crossed with antegrade wiring, ADR was associated with higher technical but not procedural success, and also higher MACE compared with parallel wiring.