Annual operator volume and procedural outcomes of chronic total occlusions treated with percutaneous coronary interventions: analysis based on 14,899 patients

BACKGROUND

Low operator and institutional volume is associated with poorer procedural and long-term clinical outcomes in patients treated with percutaneous coronary interventions (PCI). This study was aimed at evaluating the relationship between operator volume and procedural outcomes of patients treated with PCI for chronic total occlusion (CTO).

METHODS

Data were obtained from the national registry of percutaneous coronary interventions (ORPKI) collected from January 2014 to December 2020. The primary endpoint was a procedural success, defined as restoration of thrombolysis in myocardial infarction (TIMI) II/III flow without in-hospital cardiac death and myocardial infarction, whereas secondary endpoints included periprocedural complications.

RESULTS

Data of 14,899 CTO-PCIs were analyzed. The global procedural success was 66.1%. There was a direct relationship between the annual volume of CTO-PCIs per operator and the procedural success (OR: 1.006 [95% CI: 1.003-1.009]; P<0.001). The nonlinear relationships of annualized CTO-PCI volume per operator and adjusted outcome rates revealed that operators performing 40 CTO cases per year had the best procedural outcomes in terms of technical success (TIMI flow II/III after PCI), coronary artery perforation rate and any periprocedural complications rate (P<0.0001). Among the other factors associated with procedural success, the following can be noted: multi-vessel, left main coronary artery disease (as compared to single-vessel disease), the usage of rotablation as well as PCI within bifurcation.

CONCLUSIONS

High-volume CTO operators achieve greater procedural success with a lower frequency of periprocedural complications. Higher annual caseload might increase the overall quality of CTO-PCI.

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.

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 impacts of percutaneous coronary intervention to treat chronic total occlusion of right coronary artery on the 5-year prognosis: A single-centered retrospective study

BACKGROUND

Chronic total occlusions (CTO) occur in about 20% of patients referred for coronary angiography, and right coronary artery (RCA) CTO has been reported in 38-50% of the entire CTO population. Limited data on angiographic and procedural characteristics of RCA-CTO and the risk of adverse cardiac events asks for a detailed study.

METHODS

From 2010 to 2013, patients with attempted revascularization of at least one CTO lesion were included and followed up to 5 years after PCI. Eligible patients are assigned to RCA-CTO and non-RCA-CTO groups based on their target vessels. The primary endpoint was major adverse cardiovascular events (MACEs; a composite of all-cause death, myocardial infarction (MI) or rehospitalization for heart failure), and secondary endpoints were cardiac death, target lesion revascularization (TLR) and target vessel revascularization (TVR).

RESULTS

The present study included 2659 eligible patients, among which 1285 patients were assigned to the RCA-CTO group, whereas 1374 patients were assigned to the non-RCA-CTO group. Lesions in RCA had longer lesion length, higher J-CTO score, higher rates of severe vessel tortuosity, a higher percentage of Rentrop grade 2-3, and more likely to be re-try lesion than those in LAD or LCX (all P < 0.01). CTO lesions in RCA reached less successful recanalization and post-procedural TIMI 3 flow (all <0.01). Multivariate Cox analysis revealed that RCA-CTO was not associated with primary outcome MACEs. Besides MACEs, RCA-CTO was also not associated with cardiac death, but was significantly associated with TLR and TVR (adjusted HR: 1.37 [95% CI:1.07-1.76], P = 0.01; adjusted HR: 1.43 [95% CI:1.13-1.82], P = 0.003).

CONCLUSION

RCA-CTO lesions, which had more complex angiographic features, independently contributed to TLR and TVR but not to MACEs or cardiac death in the 5 years of follow-up.

Association between the atherogenic index of plasma and coronary collateral circulation in patients with chronic total occlusion

BACKGROUND

The atherogenic index of plasma (AIP) is considered an independent risk factor for coronary artery disease (CAD). The present study investigated whether AIP correlates with the formation of coronary collateral circulation (CCC) in CAD patients with chronic total occlusion (CTO).

METHODS

This retrospective study included 1093 CAD patients with CTO confirmed by coronary angiography from January 2020 to December 2020 at Beijing Anzhen Hospital. Based on the Rentrop scoring system, the patients were divided into the good CCC group and the poor CCC group. AIP was calculated by log (triglyceride/high-density lipoprotein cholesterol). Meanwhile, the study population was further divided into four groups according to the quartiles of AIP.

RESULTS

Patients in the poor CCC group exhibited significantly higher AIP compared to those in the good CCC group (0.31 ± 0.27 vs. 0.14 ± 0.24, p < 0.001). Multivariate logistic regression analysis revealed an independent association between AIP and poor CCC, regardless of whether AIP was treated as a continuous or categorical variable (p < 0.001), after adjusting for confounding factors. Besides, this association remained consistent across most subgroups. The incorporation of AIP into the baseline model significantly enhanced the accuracy of identifying poor CCC [area under the curve (AUC): baseline model, 0.661 vs. baseline model + AIP, 0.721, p for comparison < 0.001].

CONCLUSIONS

Elevated AIP is independently associated with an increased risk of poor CCC in CAD patients with CTO, and AIP may improve the ability to identify poor CCC in clinical practice.

Temporal trends of case-fatality in patients undergoing dual-injection coronary chronic total occlusion recanalization

AIMS

Recently, interventional techniques and material to treat chronic total occlusion (CTO) with percutaneous coronary intervention (PCI) have evolved significantly. Nevertheless, it is still unknown whether this progress improved treatment success and patients' outcome. In a nationwide sample, we sought to analyze trends of patients' characteristics, complications and in-hospital case-fatality of patients undergoing CTO revascularization in Germany.

METHODS AND RESULTS

We analyzed data on characteristics, treatments, and in-hospital outcomes for all coronary artery disease (CAD) patients (ICD-code I25) undergoing dual-injection CTO recanalization (OPS procedural code: 8-839.9) in Germany from 2009 to 2020. Overall, 4,998,457 inpatients aged ≥ 18 years with diagnosis of CAD were treated in German hospitals in this period. Among these, 52,879 patients (1.1%) underwent CTO recanalization. Annual number of CTO PCIs increased from 1263 in 2009 to 6435 in 2020 (β 3.48 [95% CI 3.44-3.52]; p < 0.001) in parallel with a significant decrease of case-fatality (2.2% in 2009 to 1.4% in 2020; β  - 0.60 [95% CI  - 0.82 to  - 0.39]; p < 0.001). Overall, 754 (1.4%) patients with CTO recanalization died during the in-hospital stay and in-hospital case-fatality grew exponentially with age (β 0.82 [95% CI 0.73-0.90]; p < 0.001). Significant predictors of in-hospital case fatality with an OR > 3 were cancer, stroke, hemopericardium, acute renal failure, pulmonary embolism and shock.

CONCLUSION

Annual number of CTO procedures performed in Germany increased from 2009 to 2020 with a concomitant anti-proportional decrease in the case-fatality. Our findings may help to draw more attention to predictors of in-hospital case fatality in patients hospitalized for CTO recanalization.

Association between hyperuricemia and chronic total coronary occlusion in non-chronic kidney disease populations: a cross-sectional study

BACKGROUND

Chronic total coronary occlusion (CTO) is an extremely hazardous condition that leads to various clinical phenomena and complications and results in social and economic burdens. Hyperuricemia (HU) is often associated with atherosclerosis. Few studies, however, have investigated the risk of CTO in individuals with HU and the role of traditional cardiovascular risk factors in this setting.

METHODS

A cohort of 1245 individuals without chronic kidney disease from southwest China who underwent coronary angiography between February 2018 and June 2021 were enrolled. CTO was defined as a total occlusion of any coronary artery or arteries for more than 3 months. HU was defined as a serum uric acid level of ≥420 µmol/L in men and ≥360 µmol/L in women. Univariate and multivariate logistic regression models and subgroup analyses were applied to assess the relationship between HU and CTO.

RESULTS

After adjustment, HU was noted to be associated with a 1.47-fold increase in the risk of CTO [odds ratio (OR), 1.47; 95% confidence interval (CI), 1.06-2.58; P = 0.026]. As a continuous variable, uric acid was an independent predictor of CTO (OR, 1.002; 95% CI, 1.001-1.004; P = 0.047). Subgroup analyses showed that the risk of CTO was higher among individuals under 65 years of age (OR, 2.77; 95% CI, 1.3-5.89), nonobese individuals (OR, 1.9; 95% CI, 1.16-3.1), and those with dyslipidemia (OR, 1.8; 95% CI, 1.04-3.11), while sex, smoking, hypertension, and diabetes did not show similar effects. Interaction analyses revealed no interaction among subgroups.

CONCLUSION

Among individuals residing in southwest China, HU was associated with an increased risk of CTO in non-CKD individuals, especially those under 65 years of age and nonobese and dyslipidemic individuals.

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.

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.

Relationship between homocysteine and chronic total coronary occlusion: a cross-sectional study from southwest China

BACKGROUND

Chronic total coronary occlusion is among the most complex coronary artery diseases. Elevated homocysteine is a risk factor for coronary artery diseases. However, few studies have assessed the relationship between homocysteine and chronic total coronary occlusion.

METHODS

1295 individuals from Southwest China were enrolled in the study. Chronic total coronary occlusion was defined as complete occlusion of coronary artery for more than three months. Homocysteine was divided into quartiles according to its level. Univariate and multivariate logistic regression models, receiver operating characteristic curves, and subgroup analysis were applied to assess the relationship between homocysteine and chronic total coronary occlusion.

RESULTS

Subjects in the higher homocysteine quartile had a higher rate of chronic total coronary occlusion (P < 0.001). After adjustment, the odds ratio for chronic total coronary occlusion in the highest quartile of homocysteine compared with the lowest was 1.918 (95% confidence interval 1.237-2.972). Homocysteine ≥ 15.2 μmol/L was considered an independent indicator of chronic total coronary occlusion (odds ratio 1.53, 95% confidence interval 1.05-2.23; P = 0.0265). The area under the receiver operating characteristic curve was 0.659 (95% confidence interval, 0.618-0.701; P < 0.001). Stronger associations were observed in elderly and in those with hypertension and diabetes.

CONCLUSIONS

Elevated homocysteine is significantly associated with chronic total coronary occlusion, particularly in elderly and those with hypertension and diabetes.

Association between the triglyceride glucose index and chronic total coronary occlusion: A cross-sectional study from southwest China

BACKGROUND AND AIM

Insulin resistance (IR) plays an important role in the atherosclerotic process, and the triglyceride glucose (TyG) index is a reliable indicator of IR and is strongly associated with cardiovascular disease. However, there are few studies regarding the relationship between the TyG index and chronic total coronary occlusion (CTO). Herein, the correlation between the TyG index and CTO, as well as their interactions with other traditional cardiovascular risk factors, were investigated.

METHODS AND RESULTS

We enrolled 2691 patients who underwent coronary angiography at Guangyuan Central Hospital from January 2019 to October 2021. TyG index results were used to create three groups using the trichotomous method. CTO was defined as complete occlusion of the coronary artery for ≥3 months. Univariate and multivariate logistic regression models, restricted cubic splines, receiver operating characteristic (ROC) curves, and subgroup analyses was performed. A significant correlation between the TyG index and CTO was noted. The risk of CTO was increased 2.09-fold in the group with the highest TyG compared with the lowest (OR, 2.09; 95 % CI, 1.05-4.17; P = 0.036). In addition, there was a linear dose-response relationship between the TyG index and CTO (nonlinear P = 0.614). The area under the ROC curve was 0.643 (95 % CI, 0.572-0.654). Using subgroup analyses, we observed that the TyG index was associated with a significantly higher risk of CTO in males and smokers.

CONCLUSIONS

An elevated TyG index was related to the risk of CTO and may constitute a meaningful predictor of CTO, particularly in males and in smokers.

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

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

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.

Guide catheter extension use are associated with higher procedural success in chronic total occlusion percutaneous coronary interventions

BACKGROUND

Guide catheter extensions (GCEs) increase support and facilitate equipment delivery, but aggressive instrumentation may be associated with a higher risk of complications.

AIM

Our aim was to assess the impact of GCEs on procedural success and complications in patients submitted to chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

METHODS

We analyzed data from the multicenter LATAM CTO Registry. Procedural success was defined as <30% residual stenosis and TIMI 3 distal flow. Major adverse cardiac and cerebrovascular events (MACCE) was defined as the composite of all-cause death, myocardial infarction, target vessel revascularization, and stroke. Propensity score matching (PSM) was used to compare outcomes with and without GCE use.

RESULTS

From August 2010 to August 2021, 3049 patients were included. GCEs were used in 438 patients (14.5%). In unadjusted analysis, patients in the GCE group were older and had more comorbidities. The median J-CTO score and its components were higher in the GCE group. After PSM, procedural success was higher with GCE use (87.7% vs. 80.5%, p = 0.007). The incidence of coronary perforation (odds ratio [OR]: 1.46, 95% confidence interval [CI]: 0.78-2.71, p = 0.230), bleeding (OR: 1.99, 95% CI: 0.41-2.41, p = 0.986), in-hospital death (OR: 1.39, 95% CI: 0.54-3.62, p = 0.495) and MACCE (OR: 1.07, 95% CI: 0.52-2.19, p = 0.850) were similar in both groups.

CONCLUSION

In a contemporary, multicenter cohort of patients undergoing CTO PCI, GCEs were used in older patients, with more comorbidities and complex anatomy. After PSM, GCE use was associated with higher procedural success, and similar incidence of adverse outcomes.

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.

Refined metabolite profiling in the collateral circulation of chronic total occlusion of coronary arteries: Insights from a metabolomics investigation

Background and aims

To investigate the disparities in coronary collateral circulation (CCC) and peripheral serum metabolites among patients presenting with chronic total occlusion (CTO) of the coronary arteries, a non-targeted metabolic approach was employed.

Methods

A cohort of 22 patients diagnosed with CTO of coronary arteries in the context of coronary heart disease (CHD) was selected for blood sample collection from CCC and peripheral arteries. The patients were categorized into two groups, namely CTO-C and CTO-P. The Waters UPLC I-Class Plus is combined with the Q Exactive high-resolution mass spectrometer for metabolite separation and detection. The acquired raw data from mass spectrometry is subsequently imported into Compound Discoverer 3.2 software for comprehensive analysis, which seamlessly integrates the BGI Metabolome Database (BMDB), mzCloud database, and ChemSpider online database. Subsequently, the identified differential metabolites were subjected to a metabolic pathway enrichment analysis, as documented in the Kyoto Encyclopedia of Genes and Genomes (KEGG) database.

Results

A total of 403 differential metabolites were identified in CCC and peripheral serum samples from patients with CTO of coronary arteries in CHD. Compared to the CTO-P group, the CTO-C group exhibited decreased levels of metabolites such as Testosterone, dehydroepiandrosterone (DHA), deoxyacetone, while demonstrating increased levels of metabolites including Progesterone, androstanone, l-threonine. The biosynthesis pathway of steroid hormones emerges as the key metabolic pathway significantly associated with differential metabolites.

Conclusions

Through metabolomics analysis, distinct differences in the CCC and peripheral serum metabolites have been identified among patients with CTO of coronary artery. Notably, a significant association between the steroid hormone biosynthesis pathway and CCC has been observed.

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.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Evaluation and management of patients with coronary chronic total occlusions considered for revascularisation. A clinical consensus statement of the European Association of Percutaneous Cardiovascular Interventions (EAPCI) of the ESC, the European Association of Cardiovascular Imaging (EACVI) of the ESC, and the ESC Working Group on Cardiovascular Surgery

Chronic total occlusions (CTOs) of coronary arteries can be found in the context of chronic or acute coronary syndromes; sometimes they are an incidental finding in those apparently healthy individuals undergoing imaging for preoperative risk assessment. Recently, the invasive management of CTOs has made impressive progress due to sophisticated preinterventional assessment, including advanced non-invasive imaging, the availability of novel and dedicated tools for CTO percutaneous coronary intervention (PCI), and experienced interventionalists working in specialised centres. Thus, it is crucial that referring physicians who see patients with CTO be aware of recent developments and of the initial evaluation requirements for such patients. Besides a careful history and clinical examination, electrocardiograms, exercise tests, and non-invasive imaging modalities are important for selecting the patients most suitable for CTO PCI, while others may be referred to coronary artery bypass graft or optimal medical therapy only. While CTO PCI improves angina and reduces the use of antianginal drugs in patients with symptoms and proven ischaemia, hibernation and/or wall motion abnormalities at baseline or during stress, the effect of CTO PCI on major cardiovascular events is still controversial. This clinical consensus statement specifically focuses on referring physicians, providing a comprehensive algorithm for the preinterventional evaluation of patients with CTO and the current evidence for the clinical effectiveness of the procedure. The proposed care track has been developed by members and with the support of the European Association of Percutaneous Cardiovascular Interventions (EAPCI), the European Association of Cardiovascular Imaging (EACVI), and the European Society of Cardiology (ESC) Working Group on Cardiovascular Surgery.

Coronary Physiology as Part of a State-of-the-Art Percutaneous Coronary Intervention Strategy: Lessons from SYNTAX II and Beyond

The use of coronary physiology allows for rational decision making at the time of PCI, contributing to better patient outcomes. Yet, coronary physiology is only one aspect of optimal revascularization. State-of-the-art PCI must also consider other important aspects such as intracoronary imaging guidance and specific procedural expertise, as tested in the SYNTAX II study. In this review, we highlight the technical aspects pertaining to the use of physiology as used in that trial and offer a glimpse into the future with emerging physiologic metrics, including functional coronary angiography, which have already established themselves as useful indices to guide decision making.

Successful treatment by recross IVUS-guided reentry in coronary total occlusion: STRIVE-CTO

Complex coronary total occlusion (CTO) lesions percutaneous treatment, especially in contexts where traditional antegrade strategies have failed and retrograde approaches are unsuitable, due to lack of interventional collaterals or high risk of complications, presents a considerable challenge for interventional cardiologists. Antegrade dissection reentry has historically offered a bailout strategy in cases with unsuccessful antegrade wire escalation. Nevertheless, the technique-whether employing dual-lumen microcatheters or dedicated reentry devices, such as Stingray-encounters several limitations, particularly when the delivery of the system is not possible, or extraplaque large hematomas, which complicates reentry. This paper introduces an innovative technique combining the use of the Recross MC Dual Microcatheter with real-time intravascular ultrasound guidance for refined re-wiring in CTO interventions. This approach facilitates accurate reentry zone selection and ensures precise, controlled puncturing into the true lumen, thereby enabling safe and predictable CTO recanalization.

Microvascular Complications Are Associated With Coronary Collateralization in Type 2 Diabetes and Chronic Occlusion

CONTEXT

Coronary collateral (CC) vessel development appears to be protective with regard to adverse cardiovascular events and survival in patients with coronary chronic total occlusion (CTO). The influence of type 2 diabetes mellitus (T2DM) on CC growth has been controversial. In particular, the role of diabetic microvascular complications (DMC) in determining coronary collateralization has not been elucidated.

OBJECTIVE

To investigate whether patients with DMC presented differences in CC vessel presence and grading as compared with patients without DMC.

METHODS

We conducted a single-center observational study, including consecutive T2DM patients, without previous cardiovascular history, undergoing a clinically indicated coronary angiography for chronic coronary syndrome (CCS) and angiographic evidence of at least one CTO. Patients were subdivided into 2 study groups according to the presence/absence of at least one DMC (neuropathy, nephropathy, or retinopathy). The presence and grading of angiographically visible CC development from the patent vessels to the occluded artery were assessed using the Rentrop classification.

RESULTS

We enrolled 157 patients (mean age 68.6 ± 9.8 years; 120 [76.4%] men). Patients with DMC (75 [47.8%]) had a higher prevalence of CC (69 [92.0%] vs 62 [75.6%], P = .006) and high-grade CC (55 [73.3%] vs 39 [47.6%], P = .001) compared with those without, and we found a positive association between the number of DMC in each patient and the prevalence of high-grade CC.

CONCLUSION

Among T2DM patients with coronary CTO, the presence of DMC was associated with a high CC development.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Iodixanol-associated acute kidney injury and prognosis in patients undergoing elective percutaneous coronary intervention: a prospective, multi-center study

OBJECTIVE

To evaluate iodixanol-associated acute kidney injury (AKI) and prognosis in patients undergoing elective percutaneous coronary intervention (PCI).

METHODS

Patients undergoing elective PCI and iodixanol administration were prospectively enrolled in 8 centers between May 2020 and November 2021. The primary endpoint was AKI, defined as an increase in SCr of ≥ 0.3 mg/dL (26.4 μmol/L) or relative elevation ≥ 50% from baseline in the 48-72 h after PCI. Prognosis evaluations included the major adverse renal and cardiovascular events (MARCE): all-cause mortality, new-onset renal replacement therapy (NRRT), non-fatal myocardial infarction, and non-fatal stroke. AKI predictors were identified using multivariable logistic regression and associations between AKI and outcomes were examined using Cox regression.

RESULTS

A total of 3630 patients were included in the final analysis and 2.9% of patients (107/3,630) suffered AKI. Among them, 95.3% (102/107) of AKI were stage 1, and 4.6% (5/107) of stage 2. The multivariable analysis indicated that age over 75-year-old, diabetes, NT-pro-BNP > 300 pg/mL, hemoglobin < 110 g/L, eGFR < 60 mL/min/1.73m2, and diuretics were independently associated with AKI (p < 0.05). After a median follow-up of 13 months, MARCE occurred in 3.6% (131/3630) of the study population, and their incidence was higher in AKI (9.4%, 10/107) vs. non-AKI patients (3.4%, 121/3,523). However, after multivariable adjustment, there was no statistically significant association between AKI and MARCE (p = 0.382).

CONCLUSIONS

In patients undergoing elective PCI, cases of iodixanol-associated AKI were mostly mild and, after multivariable adjustment, held no statistically significant association with MARCE on mid-term follow-up.

CLINICAL RELEVANCE STATEMENT

The incidence of iodixanol-associated AKI was low and mainly limited to mild renal impairment in patients undergoing elective PCI. Physicians should provide adequate contrast for coronary artery evaluation and, at the same time, minimize the contrast volume.

KEY POINTS

• The incidence of iodixanol-associated acute kidney injury was low and mostly limited to mild renal impairment. • Iodixanol administration had no statistically significant impact on the major adverse renal and cardiovascular events in patients undergoing elective percutaneous coronary intervention.

Clinical Outcome of Paclitaxel-Coated Balloon Angioplasty Versus Drug-Eluting Stent Implantation for the Treatment of Coronary Drug-Eluting Stent In-Stent Chronic Total Occlusion

AIMS

In-stent chronic total occlusion (IS-CTO) represents a unique challenge for percutaneous coronary intervention. Whether the optimal treatment for IS-CTO is angioplasty with paclitaxel-coated balloons (PCBs) or repeat stenting with drug-eluting stents (DESs) is unclear. We aimed to evaluate the long-term clinical outcome of PCB angioplasty and DES repeat stenting for DES IS-CTO.

METHODS

We retrospectively included patients with DES IS-CTO who underwent successful PCB angioplasty or DES repeat stenting from January 2016 to December 2019. The primary endpoints were major adverse cardiac events (MACEs), including cardiac death, myocardial infarction, and target lesion revascularization (TLR). Cox proportional hazards model was performed to compare the risk of MACEs between PCB angioplasty and DES repeat stenting, and to further explore the prognostic factors of patients with DES IS-CTO.

RESULTS

A total of 214 patients with DES IS-CTO were enrolled: 78 patients (36.4%) treated with PCB and 136 patients (63.6%) treated with DES respectively. The median follow-up was 1160 days, and MACEs were observed in 28.2% of patients with PCB angioplasty versus 26.5% of patients with DES repeat stenting (P = 0.784), mainly driven by TLR (21.8% vs. 19.9%, P = 0.735). There was no significant difference in the risk of MACEs between the PCB group and the DES group (hazard ratio [HR] 1.25, 95% confidence interval [CI] 0.64-2.46, P = 0.512). Multivariate Cox analysis revealed that chronic kidney disease and ≥ 3 stent layers in the lesion were independent predictors of MACEs, while switching to another antiproliferative drug was an independent protective factor (all P < 0.05).

CONCLUSIONS

PCB angioplasty was an effective alternative treatment strategy for DES IS-CTO, which had similar long-term outcomes to DES repeat stenting in contemporary practice, but both were accompanied by a high rate of long-term MACEs. Improving the poor prognosis of patients with DES IS-CTO remains a challenge.

Early and long-term prognosis in patients with remaining chronic total occlusions after revascularization attempt. A cohort study from the SKEJ-CTO registry

OBJECTIVES

The present study aimed to compare safety and long-term prognosis of patients with chronic total coronary occlusions (CTO) stratified for remaining CTOs after percutaneous coronary intervention (PCI).

DESIGN

The study cohort consisted of patients with coronary artery disease who underwent CTO PCI in a high volume tertiary center from 2009 to 2019 and were registered in Danish high-quality registers. Patients with successful PCI of all CTOs were compared to patients with ≥1 remaining CTO post-procedural. Primary endpoints were analysed using Cox-regression and Kaplan-Meier estimates, and included all-cause mortality, major adverse cardio- and cerebrovascular events (MACCE) and a 30-day safety endpoint.

RESULTS

Procedural success rate was 87.7%, and 76.5% of patients had all CTO(s) opened post-PCI. Safety endpoint occurred in 4.6% of patients, and more frequently in patients with remaining CTO(s) (RD 4.9, 95%CI 0.1, 9.8). All-cause mortality was higher in patients with remaining CTO(s) (Unadjusted HR 1.65, 95% CI 1.03, 2.47, p = .015. Adjusted HR 1.32, 95%CI 0.88-1.99, p = .18) after eight years of follow-up. Risk of MACCE was significantly higher in patients with remaining CTO(s) (Unadjusted HR 1.79, 95% CI 1.34-2.41, p < .001. Adjusted HR 1.51, 95% CI 1.11-2.05, p = .009).

CONCLUSIONS

In our centre, CTO PCI was associated with high success rate and low risk of 30-days complications. Presence of remaining CTO(s) after final revascularization attempt was associated with higher but statistically insignificant long-term mortality but was an independent predictor of MACCE.

Long-term improvement of symptoms of angina pectoris after successful revascularization of coronary artery chronic total occlusions

Objectives. To compare long-term angina pectoris relief of successful versus failed percutaneous coronary intervention of chronic total occlusions (CTO PCI). Background. Previous studies demonstrate better short-term angina pectoris relief of CTO PCI than with optimal medical treatment (OMT), however, data on the long-term effects are lacking. Methods. 295 patients undergoing CTO PCI were analyzed retrospectively, with a follow-up evaluation of symptoms of angina pectoris and all-cause death one to four years after the intervention. The primary outcome was long-term relief of symptoms of angina pectoris. Secondary outcomes included a composite of major adverse cardiovascular events (MACE), including all-cause death, myocardial infarction, stroke, and later target vessel revascularization (TVR). At follow-up, patients were interviewed for symptoms of angina pectoris at 1, 6, 12, and 22 to 48 months after the intervention. Results. CTO PCI was successful in 225 (76%) patients and failed in 70 (24%) patients. Short-term (six months) relief of angina pectoris was observed in both groups, but only the successful CTO PCI group showed long-term relief. The Kaplan-Meier curves of all-cause death did not differ between the groups (p = .715). The final follow-up was a mean (range) of 37 (25 to 44) months after the intervention in the successful CTO PCI group, and 33 (28 to 48) months in the failed CTO PCI group. Conclusions. Successful CTO PCI is associated with better long-term relief of symptoms of angina pectoris compared to failed CTO PCI.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Outcomes of chronic total occlusion percutaneous coronary intervention from the RAIAN (RAjaie - Iran) registry

OBJECTIVE

While most of the evidence in CTO interventions emerge from Western and Japanese studies, few data have been published up today from the Middle East. Objective of this study was to evaluate technical success rates and clinical outcomes of an Iranian population undergoing CTO PCI in a tertiary referral hospital. Moreover, we sought to evaluate the efficacy of our CTO teaching program.

METHODS

This is a retrospective single-center cohort study including 790 patients who underwent CTO PCI performed by operators with different volumes of CTOs PCI performed per year. According to PCI result, all patients have been divided into successful (n = 555, 70.3 %) and unsuccessful (n = 235, 29.7 %) groups. Study endpoints were Major Adverse Cardiovascular Events and Health Status Improvement evaluated using the Seattle Angina Questionnaire at one year.

RESULTS

A global success rate of 70 % for antegrade and 80 % for retrograde approach was shown despite the lack of some CTO-dedicated devices. During the enrollment period, the success rate increased significantly among operators with a lower number of CTO procedures per year. One-year MACE rate was similar in both successful and unsuccessful groups (13.5 % in successful and 10.6 % in unsuccessful group, p = 0.173). One year patients' health status improved significantly only in successful group.

CONCLUSIONS

No significant differences of in-hospital and one-year MACE were found between the successful and unsuccessful groups. Angina symptoms and quality of life significantly improved after successful CTO PCI. The RAIAN registry confirmed the importance of operator expertise for CTO PCI success.

Wire-based antegrade dissection re-entry technique for coronary chronic total occlusions percutaneous revascularization: Experience from the ERCTO Registry

BACKGROUND

The recent development and widespread adoption of antegrade dissection re-entry (ADR) techniques have been underlined as one of the antegrade strategies in all worldwide CTO consensus documents. However, historical wire-based ADR experience has suffered from disappointing long-term outcomes.

AIMS

Compare technical success, procedural success, and long-term outcome of patients who underwent wire-based ADR technique versus antegrade wiring (AW).

METHODS

One thousand seven hundred and ten patients, from the prospective European Registry of Chronic Total Occlusions (ERCTO), underwent 1806 CTO procedures between January 2018 and December 2021, at 13 high-volume ADR centers. Among all 1806 lesions attempted by the antegrade approach, 72% were approached with AW techniques and 28% with wire-based ADR techniques.

RESULTS

Technical and procedural success rates were lower in wire-based ADR than in AW (90.3% vs. 96.4%, p < 0.001; 87.7% vs. 95.4%, p < 0.001, respectively); however, wire-based ADR was used successfully more often in complex lesions as compared to AW (p = 0.017). Wire-based ADR was used in most cases (85%) after failure of AW or retrograde procedures. At a mean clinical follow-up of 21 ± 15 months, major adverse cardiac and cerebrovascular events (MACCEs) did not differ between AW and wire-based ADR (12% vs. 15.1%, p = 0.106); both AW and wire-based ADR procedures were associated with significant symptom improvements.

CONCLUSIONS

As compared to AW, wire-based ADR is a reliable and effective strategy successfully used in more complex lesions and often after the failure of other techniques. At long-term follow-up, patient's MACCEs and symptoms improvement were similar in both antegrade techniques.

Evaluation of right-ventricular function by two-dimensional echocardiography and two-dimensional speckle-tracking echocardiography in patients with successful RCA CTO recanalization

OBJECTIVES

Chronic total occlusion (CTO) of the right coronary artery (RCA) is common in patients with coronary artery disease. Although revascularization techniques and success rates have improved significantly in recent years, there are still no studies investigating possible effects of successful recanalization of RCA CTO on the right-ventricular (RV) function. With this study, we aimed to evaluate RV function after recanalization of the RCA by two-dimensional transthoracic echocardiography (2DE) and additional two-dimensional speckle-tracking echocardiography (2DSTE).

METHODS AND RESULTS

Our analysis included 102 patients undergoing successful RCA CTO recanalization at the University Medical Center of Mainz. All patients underwent 2DE and 2DSTE to assess RV function before PCI procedure and 6 months after successful revascularization. We found an altered RV function in our collective at baseline assessed by 2DSTE with a significant improvement at 6 month follow-up (baseline RV free wall strain: - 20.7 [- 6.3 to - 32.0] % vs. - 23.4 [- 8.3 to - 39.3] % at follow-up, p < 0.001 and baseline RV global strain - 15.9 [- 6.0 to - 25.7] % vs. - 17.9 [- 7.0 to - 29.5] % at follow-up, p < 0.001).

CONCLUSION

RV function was altered in patients with RCA CTO and showed significant improvement after successful recanalization. We also noticed an improvement in patient-reported clinical symptoms. Our study suggests that CTO procedure is a beneficial treatment option in symptomatic patients with RCA CTO.

Machine learning-based analysis of risk factors for chronic total occlusion in an Asian population

OBJECTIVES

Chronic total occlusion (CTO) is a form of coronary artery disease (CAD) requiring percutaneous coronary intervention. There has been minimal research regarding CTO-specific risk factors and predictive models. We developed machine learning predictive models based on clinical characteristics to identify patients with CTO before coronary angiography.

METHODS

Data from 1473 patients with CAD, including 317 patients with and 1156 patients without CTO, were retrospectively analyzed. Partial least squares discriminant analysis (PLS-DA), random forest (RF), and support vector machine (SVM) models were used to identify CTO-specific risk factors and predict CTO development. Receiver operating characteristic (ROC) curve analysis was performed for model validation.

RESULTS

For CTO prediction, the PLS-DA model included 10 variables; the ROC value was 0.706. The RF model included 42 variables; the ROC value was 0.702. The SVM model included 20 variables; the ROC value was 0.696. DeLong's test showed no difference among the three models. Four variables were present in all models: sex, neutrophil percentage, creatinine, and brain natriuretic peptide (BNP).

CONCLUSIONS

Validation of machine learning prediction models for CTO revealed that the PLS-DA model had the best prediction performance. Sex, neutrophil percentage, creatinine, and BNP may be important risk factors for CTO development.

Three-year outcomes of A Randomized Multicentre Trial Comparing Revascularization and Optimal Medical Therapy for Chronic Total Coronary Occlusions (EuroCTO)

BACKGROUND

Percutaneous coronary intervention (PCI) for chronic total coronary occlusions (CTO) improves clinical symptoms and quality of life. The longer-term safety of PCI compared to optimal medical therapy (OMT) remains uncertain.

AIMS

We sought to evaluate the long-term safety of PCI for CTO in a randomised trial as compared to OMT.

METHODS

A total of 396 patients with a symptomatic CTO were enrolled into a randomised, multicentre clinical trial comparing PCI and OMT. Half of the patients had a single CTO; the others had multivessel disease. Non-CTO lesions were treated prior to randomisation (2:1 ratio). During follow-up, crossover from OMT to PCI occurred in 7.3% (1 year) and 17.5% (3 years) of patients.

RESULTS

At 3 years, the incidence of cardiovascular death or nonfatal myocardial infarction was not significantly different between the groups (OMT 3.7% vs PCI 6.2%; p=0.29). By per-protocol analysis, the difference remained non-significant (OMT 5.7% vs PCI 4.7%; p=0.67). Overall, major adverse cardiovascular events (MACE) were more frequent with OMT (OMT 21.2% vs PCI 11.2%), largely because of ischaemia-driven revascularisation. The rates of stroke or hospitalisation for bleeding were not different between the groups.

CONCLUSIONS

At 3 years there was no difference in the rate of cardiovascular death or myocardial infarction between PCI or OMT among patients with a remaining single coronary CTO. The MACE rate was higher in the OMT group due largely to ischaemia-driven revascularisation. CTO PCI appears to be a safe option for patients with a single remaining significant coronary CTO. CinicalTrials.gov: NCT01760083.

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.

CTO and Bifurcation Lesions: An Expert Consensus From the European Bifurcation Club and EuroCTO Club

Knowledge in the field of bifurcation lesions and chronic total occlusions (CTOs) has progressively improved over the past 20 years. Therefore, the European Bifurcation Club and the EuroCTO Club have decided to write a joint consensus statement to share general knowledge and practical approaches in this complex field. When percutaneously treating CTOs, bifurcation lesions with relevant side branches (SBs) are found in approximately one-third of cases (35% at the proximal cap, 38% at the distal cap, and 27% within the CTO body). Occlusion of a relevant SB is not rare and has been shown to be associated with procedural complications and adverse outcomes. Simple bifurcation rules are very useful to prevent SB occlusion, and provisional SB stenting is the recommended approach in the majority of cases: protect the SB as soon as possible by wiring it, respect the fractal anatomy of the bifurcation by using the 3-diameter rule, and avoid using dissection and re-entry techniques. A systematic 2-stent approach can be used if needed or sometimes to connect both branches of the bifurcation. The retrograde approach can be very useful to save a relevant SB, especially in the case of a bifurcation at the distal cap or within the CTO body. Intravascular ultrasound is also a very important tool to address the difficulties with bifurcations at the proximal or distal cap and sometimes also within the CTO segment. Double-lumen microcatheters and angulated microcatheters are crucial tools to resolve access difficulties to the SB or the main branch.

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.

Stent expansion in calcified coronary chronic total occlusions: The impact of different stent platforms

OBJECTIVES

To evaluate the stent expansion of the durable-polymer Zotarolimus-eluting stent (dp-ZES), the durable-polymer Everolimus-eluting stent (dp-EES), and the bioabsorbable-polymer Sirolimus-eluting stent (bp-SES) in calcified coronary chronic total occlusions (CTO).

BACKGROUND

The newer generation stents with ultrathin struts might raise concerns regarding reduced radial strength and higher stent recoil (SR) when implanted in calcified CTOs.

METHODS

Between January 2017 and June 2021 consecutive patients with CTO undergoing percutaneous coronary intervention with dp-ZES, dp-EES, or bp-SES were evaluated. The analysis was performed in calcific and in noncalcific CTOs. Quantitative coronary angiography analysis was used to assess diameter stenosis (DS), absolute and relative SR, absolute and relative focal SR, absolute and relative balloon deficit (BD), and absolute and relative focal BD. The primary endpoint was DS.

RESULTS

A total of 213 CTOs were evaluated, 115 calcific CTOs (dp-ZES:25, dp-EES:29, bp-SES:61) and 98 non-calcific CTOs (dp-ZES:41, dp-EES:11, bp-SES:46). In calcific CTOs, residual DS was lower in dp-ZES than in dp-EES and bp-SES (-1.00% [-6.50-6.50] vs. 13.00% [7.0-19.00] vs. 15.00% [5.00-20.00]; p < 0.001). Dp-ZES was also an independent predictor of residual DS ≤ 10% (OR 11.34, 95% CI 2.6-49.43, p = 0.001). Absolute and relative focal SR and absolute and relative SR were similar between dp-ZES, dp-EES, and bp-SES (p = 0.913, p = 0.890, p = 0.518, p = 0.426, respectively). In noncalcified CTOs, the residual DS was similar in the three groups (p = 0.340). High relative focal SR was less frequent in dp-ZES than in dp-EES and in bp-SES (19.5% vs. 54.5% vs. 37.0%; p < 0.048).

CONCLUSIONS

The three stent platforms demonstrated an overall low residual DS when implanted in CTOs. However, dp-ZES was associated with the lowest residual DS and identified as independent predictor of residual DS ≤ 10% in patients with calcific CTOs. Dp-ZES was associated with a lower incidence of high relative focal stent recoil, in noncalcific CTOs. Balloon deficit might be considerate as a surrogate for stent expansion in calcified CTOs.

Computed tomography perfusion and angiography in patients with chronic total occlusion undergoing percutaneous coronary intervention

BACKGROUND AND AIMS

Myocardial perfusion imaging (MPI) and anatomical imaging with coronary computed tomography angiography (CCTA) can play an important role in the preprocedural planning of a chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We aimed to establish the feasibility of a novel dynamic computed tomography perfusion (CTP) analysis for the assessment of myocardial perfusion before and after a successful recanalization of CTO in patients undergoing CCTA as part of a standard preprocedural workup.

METHODS

In a prospective observational study symptomatic patients underwent dynamic CTP on a dual-source CT scanner both before and 3 months after successful CTO PCI.

RESULTS

Twenty-seven patients completed the study (63 ± 8 years old, 78% male). Following successful CTO PCI, there was a significant reduction in the ischemic burden (5 [5-7] versus 1 [0-2] segments, p < 0.001), and improvement in myocardial blood flow (85.3 [71.7-94.1] versus 134.6 [123.8-156.9] mL/min, p < 0.001) resulting in an increase in the relative flow reserve (0.49 [0.41-0.57] versus 0.88 [0.74-0.95], p < 0.001).

CONCLUSIONS

CTP emerges as a robust and safe method for MPI in CTO patients. The single imaging session assessment of both coronary anatomy and perfusion with CT lends itself to precise disease phenotyping in the challenging population of CTO patients.

Single versus Dual-Operator Approaches for Percutaneous Coronary Interventions within Chronic Total Occlusion-An Analysis of 27,788 Patients

(1) Background: Since the treatment of chronic total occlusion (CTO) with percutaneous coronary intervention (PCI) is associated with high procedural complexity, it has been suggested to use a multi-operator approach. This study was aimed at evaluating the procedural outcomes of single (SO) versus dual-operator (DO) CTO-PCI approaches. (2) Methods: This retrospective analysis included data from the Polish Registry of Invasive Cardiology Procedures (ORPKI), collected between January 2014 and December 2020. To compare the DO and SO approaches, propensity score matching was introduced with equalized baseline features. (3) Results: The DO approach was applied in 3604 (13%) out of 27,788 CTO-PCI cases. Patients undergoing DO CTO-PCI experienced puncture-site bleeding less often than the SO group (0.1% vs. 0.3%, p = 0.03). No differences were found in the technical success rate (successful revascularization with thrombolysis in myocardial infarction flow grade 2/3) of the SO (72.4%) versus the DO approach (71.2%). Moreover, the presence of either multi-vessel (MVD) or left main coronary artery disease (LMCA) (odds ratio (OR), 1.67 (95% confidence interval (CI), 1.20-2.32); p = 0.002), as well as lower annual and total operator volumes of PCI and CTO-PCI, could be noted as factors linked with the DO approach. (4) Conclusions: Due to the retrospective character, the findings of this study have to be considered only as hypothesis-generating. DO CTO-PCI was infrequent and was performed on patients who were more likely to have LMCA lesions or MVD. Operators collaboratively performing CTO-PCIs were more likely to have less experience. Puncture-site bleeding occurred less often in the dual-operator group; however, second-operator involvement had no impact on the technical success of the intervention.

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.

Anemia and periprocedural complications determine contrast-associated acute kidney injury after recanalization of chronic coronary occlusions in chronic kidney disease

BACKGROUND

Contrast-associated acute kidney injury (CA-AKI) is a potential risk associated with the percutaneous coronary interventions (PCI) for chronic total coronary occlusions (CTO) particularly with pre-existing chronic kidney disease (CKD). The determinants of CA-AKI in patients with pre-existing CKD in an era of advanced strategies of CTO recanalization techniques need to be considered for a risk evaluation of the procedure.

METHODS

A consecutive cohort of 2504 recanalization procedures for a CTO between 2013 and 2022 was analyzed. Of these, 514 (20.5%) were done in patients with CKD (estimated glomerular filtration rate < 60 ml/min based on the most recently used CKD Epidemiology Collaboration equation).

RESULTS

The rate of patients classified to have CKD would be lower with 14.2% using the Cockcroft-Gault equation, and 18.1% using the modified Modification of Diet in Renal Disease equation. The technical success was high with 94.9% and 96.8% (p = 0.04) between patients with and without CKD. The incidence of CA-AKI was 9.9% versus 4.3% (p < 0.001). The major determinants of CA-AKI in patients with CKD were the presence of diabetes and a reduced ejection fraction, as well as periprocedural blood loss, whereas a higher baseline hemoglobin and the use of the radial approach prevented CA-AKI.

CONCLUSIONS

In patients with CKD CTO PCI could be performed successfully at a higher cost of CA-AKI. Correcting preprocedural anemia and avoiding intraprocedural blood loss may reduce the incidence of CA-AKI.

Gender differences in percutaneous coronary intervention for chronic total occlusions from the ERCTO study

BACKGROUND

Gender-specific data addressing percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) in female patients are scarce and based on small sample size studies.

AIMS

We aimed to analyze gender-differences regarding in-hospital clinical outcomes after CTO-PCI.

METHODS

Data from 35,449 patients enrolled in the prospective European Registry of CTOs were analyzed. The primary outcome was the comparison of procedural success rate in the two cohorts (women vs. men), defined as a final residual stenosis less than 20%, with Thrombolysis In Myocardial Infarction grade flow = 3. In-hospital major adverse cardiac and cerebrovascular events (MACCEs) and procedural complications were deemed secondary outcomes.

RESULTS

Women represented 15.2% of the entire study population. They were older and more likely to have hypertension, diabetes, and renal failure, with an overall lower J-CTO score. Women showed a higher procedural success rate (adjusted OR [aOR] = 1.115, confidence interval [CI]: 1.011-1.230, p = 0.030). Apart from previous myocardial infarction and surgical revascularization, no other significant gender differences were found among predictors of procedural success. Antegrade approach with true-to-true lumen techniques was more commonly used than retrograde approach in females. No gender differences were found regarding in-hospital MACCEs (0.9% vs. 0.9%, p = 0.766), although a higher rate of procedural complications was observed in women, such as coronary perforation (3.7% vs. 2.9%, p < 0.001) and vascular complications (1.0% vs. 0.6%, p < 0.001).

CONCLUSIONS

Women are understudied in contemporary CTO-PCI practice. Female sex is associated with higher procedural success after CTO-PCI, yet no sex differences were found in terms of in-hospital MACCEs. Female sex was associated with a higher rate of procedural complications.

Intraplaque wiring enables drug-coated balloons to be utilized for percutaneous recanalization of chronically occluded coronary arteries

OBJECTIVES

This study aimed to determine whether drug-coated balloon (DCB) angioplasty following intraplaque wiring and the use of modified balloons is safe and effective in the percutaneous treatment of coronary chronic total occlusions (CTOs).

BACKGROUND

DCB is an alternative therapeutic option without the limitations of permanent vascular implants. However, its efficacy in CTOs has yet to be confirmed. The combination of modified balloons and DCB can be effectively applied when the intraplaque passage of the guidewire is achieved in CTOs.

METHODS

Data from 124 consecutive CTO lesions (105 patients) treated at our hospital between February 2016 and December 2020 were screened for inclusion and retrospectively analyzed. Among the 118 lesions successfully recanalized, intraplaque wiring was achieved in 108, and 85 were treated by the DCB-only approach following cutting/scoring balloon dilatation.

RESULTS

Follow-up data were available for 82 lesions (71 patients). The median occlusion length was 18.5 mm, and the J-CTO score was 1.7 ± 0.9. No in-hospital major adverse cardiac events occurred, including abrupt vessel closure. During the median 29-month follow-up period, target lesion revascularization was performed for 10 lesions. Follow-up coronary angiography (8.7 ± 3.9 months after the index procedure) was performed for 64 lesions, demonstrating late lumen loss of -0.15 mm (interquartile range -0.4 to 0.23 mm), binary restenosis (diameter stenosis ≥50%) in 12 lesions (18.8%), and late lumen enlargement in 37 (57.8%).

CONCLUSION

The DCB-only approach following the use of modified balloons is a promising strategy for coronary CTOs when intraplaque wiring is achieved.