Patients undergoing dialysis are at a high risk of cardiovascular death, and the prevalence of coronary complex lesions is high.

This study aimed to analyze the characteristics, outcomes, and adverse events of chronic total occlusion (CTO)-percutaneous coronary intervention (PCI) in patients undergoing dialysis.

We examined 11,664 patients enrolled in the Japanese CTO-PCI Expert Registry between January 2014 and December 2022.

Dialysis was performed in 6.9% of all patients with CTO and was associated with a lower technical success rate than those who did not undergo dialysis (85.4% vs. 92.4%, p < 0.001). Dialysis was an independent predictor of technical failure (odds ratio, 1.510; 95% CI, 1.200-1.910; p < 0.001). Patients on dialysis had increased procedure times and puncture site complication rates; however, they did not show an increased incidence of major adverse cardiac or cerebrovascular events (MACCE) (1.6% vs. 1.8%, p = 0.890). PCI in patients on dialysis necessitated the high rate of debulking device use, even when calcification was not severe, and hard tip load wire selection for CTO crossing. In patients on dialysis, calcification, lesion tortuosity, and reattempts were associated with technical failure. Patients on dialysis without these predictors achieved a high technical success rate equivalent to that of patients not on dialysis.

PCI in patients undergoing dialysis was associated with a low success rate but could be performed safely without increasing MACCE. Debulking devices may be required for calcification, and careful attention is required to prevent puncture site complications.

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.

Chronic total occlusions (CTOs) of coronary arteries present a significant challenge in cardiology, with long-term outcomes following percutaneous coronary intervention (PCI) for CTOs remaining variable and unpredictable. The Naples prognostic score (NPS), which incorporates markers of nutritional status and systemic inflammation, has shown potential in predicting outcomes in various cardiovascular settings. This study evaluates the NPS as a predictor of long-term outcomes after PCI for CTOs.

A retrospective analysis was conducted on 287 patients who underwent coronary angiography. Patients were categorized into non-CTO-PCI and CTO-PCI groups. Patients were further stratified based on survival status. Cox regression and Kaplan-Meier survival analyses were used to evaluate the association between NPS and long-term outcomes.

The mean age of the study population was 63.5 ± 10.6 years, with 28.6% being female. The NPS was significantly higher in the CTO-PCI group compared to the non-CTO-PCI group ( P = 0.004) and was also elevated in the non-survival group ( P = 0.004). Multivariable Cox regression analysis identified NPS as an independent predictor of mortality ( P = 0.015). Kaplan-Meier analysis demonstrated significantly higher mortality in patients with an elevated NPS ( P = 0.009).

The NPS is a valuable independent predictor of long-term mortality in patients undergoing CTO-PCI. Incorporating NPS into existing risk stratification models could improve predictive accuracy and guide individualized patient management. Further prospective studies are warranted to validate these findings and explore interventions targeting inflammation and nutrition in this high-risk population.

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.

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.

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.

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.

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

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.

Chronic total occlusion (CTO) percutaneous coronary intervention is a complex procedure and is associated with considerable risk of complications. Several success and complication scores have been developed; however, data regarding their external validation in other populations such as Latin America are scarce. This study aimed to evaluate the accuracy of the main predictors of success and complications in a broad cohort of procedures in the Latin American (LATAM) CTO registry. From April 2008 to December 2023, 3,706 consecutive procedures listed in the LATAM CTO registry were screened. Of these, 2,835 procedures had sufficient information to analyze the Multicenter CTO Registry in Japan (J-CTO); Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS); Ostial location, Rentrop grade, and Age (ORA); Clinical and Lesion-related Score (CL-score); and EuroCTO Score (CASTLE) success scores. The complication scores were PROGRESS (MACE, mortality, and pericardiocentesis) and Outcomes, Patient health status, and Efficiency iN Chronic Total Occlusion hybrid procedures (OPEN-CTO),OPEN-CLEAN. The J-CTO and CASTLE scores demonstrated the highest areas under the curve (AUC) of 0.718 and 0.703, respectively. The AUC value for the CL-score was 0.685, whereas the PROGRESS score had an AUC of 0.598 and the ORA AUC was 0.545. The level of agreement between scores was low; only 4% of the procedures were classified as difficult or very difficult by all scores and <1% were classified as easy by all 5 scores. Of the complication scores, PROGRESS mortality (AUC 0.651) and PROGRESS MACE (AUC 0.588) showed the best performance, identifying groups with >10% event rate. These results may improve the selection of revascularization techniques, especially for patient demographics that are historically underrepresented in CTO research.

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).

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.

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.

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.

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

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.

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.

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).

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

To systematically investigate and summarize the utility of coronary computed tomographic angiography (CCTA) in the management of chronic total occlusion (CTO)-percutaneous coronary intervention (PCI).

The authors searched the four databases between 2005 and 2023 for studies investigating the role of CCTA and invasive coronary angiograms (ICA) images when used as the pre-procedural tool for CTO-PCI. Efficacy and safety of CCTA in CTO-PCI treatment as a pre-procedural assessment tool was evaluated.

Forty-seven studies were finally chosen for this systematic review. CCTA had a high degree of agreement with ICA when applied for J-CTO scoring system. A J-CTO (Multicenter CTO Registry in Japan) score > 3, together with calcification, occlusion length ≥ 20 mm, blunt stump, and bending > 45° were shared imaging risk factors on both ICA and CCTA for technique failure and guidewire crossing over 30 min. Additionally, negative remodeling and multiple diseased vessel were significant indicators on CCTA. Although patients with pre-procedural CCTA showed a trend of higher success rate and easier guidewire crossing, and CCTA showed a slightly higher predictive accuracy for process success, no significant improvement in post-PCI major adverse cardiac events of using CCTA for assessment has been achieved.

CCTA is a safe and effective pre-operative tool of CTO-PCI. Except for the shared imaging risk factors with ICA for a hard CTO-PCI including calcification, occlusion length ≥ 20 mm, blunt stump, bending > 45°, and J-CTO score > 3, factors like negative remodeling and multiple diseased vessel were also recognized as significant pre-operative assessment indicators on CCTA.

A pre-procedural assessment based on coronary computed tomographic angiography has the potential to aid in the management of chronic total occlusion percutaneous coronary intervention.

• A coronary computed tomographic angiography-based pre-procedural assessment can help chronic total occlusion-percutaneous coronary intervention management. • The recognized high-risk features detected via coronary computed tomographic angiography and invasive coronary angiograms are comparable in detecting difficult lesions and chronic total occlusion-percutaneous coronary intervention failure. • Coronary computed tomographic angiography has an additional value to be a safe and effective pre-procedural assessment tool for chronic total occlusion-percutaneous coronary intervention.

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.

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.

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

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

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

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.

Successful collateral channel (CC) crossing is an essential step in retrograde chronic total occlusion (CTO) percutaneous coronary interventions (PCIs). We previously developed a dedicated CC score based on CC size and tortuosity to facilitate target CC selection. Validation and comparison to other scoring systems were lacking. Thus, the aims of this study were to (1) validate the CC score in a larger independent cohort, and (2) compare its accuracy and clinical usefulness with the J-channel score. All coronary CTO PCIs attempted by experienced high-volume operators from January 2017 to December 2021 were enrolled. The CC and J-channel scores were calculated for all attempted CCs with bi-plane high-resolution cine angiography images. CC crossing success was defined as guidewire reaching the distal true lumen retrogradely. In total, 502 patients who received CTO PCI were included. The retrograde approach was utilized in 244 target CTOs, and a total of 329 CCs were attempted. The overall CC crossing rate was 67.8% (223 of 329) and final technical success rate 92.2% (225 of 244). The average CC score was 2.0 and average J-channel score was 0.71. The sensitivity and specificity of successful CC crossing with the CC score ≥2 were 81.2%, and 84.0%, respectively. Comparison between the CC score (area under the curve 0.87; 95% confidence interval 0.83 to 0.90) and the J-channel score (area under the curve 0.61, 95% confidence interval 0.55 to 0.67) demonstrated superior predictive performance of the CC score (p <0.001). The CC score was an easy-to-use and accurate tool for the prediction of successful CC crossing in retrograde CTO PCI. The CC score can help operators select the ideal target CC, thereby facilitating final procedural success.

Coronary calcification is common and increases the difficulty of chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

We examined the impact of calcium on procedural outcomes of 13,079 CTO PCIs performed in 12,799 patients at 46 US and non-US centers between 2012 and 2023.

Moderate or severe calcification was present in 46.6% of CTO lesions. Patients whose lesions were calcified were older and more likely to have had prior coronary artery bypass graft surgery. Calcified lesions were more complex with higher J-CTO score (3.0 ± 1.1 vs. 1.9 ± 1.2; p < 0.001) and lower technical (83.0% vs. 89.9%; p < 0.001) and procedural (81.0% vs. 89.1%; p < 0.001) success rates compared with mildly calcified or non-calcified CTO lesions. The retrograde approach was more commonly used among cases with moderate/severe calcification (40.3% vs. 23.5%; p < 0.001). Balloon angioplasty (76.6%) was the most common lesion preparation technique for calcified lesions, followed by rotational atherectomy (7.3%), laser atherectomy (3.4%) and, intravascular lithotripsy (3.4%). The incidence of major adverse cardiovascular events (MACE) was higher in cases with moderate or severe calcification (3.0% vs. 1.2%; p < 0.001), as was the incidence of perforation (6.5% vs. 3.4%; p < 0.001). On multivariable analysis, the presence of moderate/severe calcification was independently associated with lower technical success (odds ratio, OR = 0.73, 95% CI: 0.63-0.84) and higher MACE (OR = 2.33, 95% CI: 1.66-3.27).

Moderate/severe calcification was present in nearly half of CTO lesions, and was associated with higher utilization of the retrograde approach, lower technical and procedural success rates, and higher incidence of in-hospital MACE.

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

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

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

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

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

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is still challenging due to complex lesion morphology. Success rates may vary among the 3 major coronary arteries, influenced by clinical and angiographic characteristics.

This study sought to evaluate the differences in the predictors of unsuccessful PCI in first-attempt CTO lesions of the 3 major coronary arteries compared with the J-CTO (Japanese CTO) score.

This study assessed 6,408 first-attempt CTO patients from the Japanese CTO-PCI expert registry between January 2014 and December 2021, randomly assigned to derivation and validation sets. Difficulty scores for each artery were determined by assigning points to predictive unsuccessful factors.

The CTO lesions were distributed as follows: left anterior descending coronary artery: 2,245 (35%), left circumflex coronary artery: 1,131 (18%), and right coronary artery (RCA): 3,032 (47%). Regarding success rates, left circumflex coronary artery CTO had the lowest procedural success rate (90%) followed by RCA CTO (92%) and left anterior descending coronary artery CTO (94%). RCA CTO was significantly longer and more severely angulated, requiring more often the retrograde approach. A multivariate logistic analysis revealed that predictors of failed PCI were different in CTO lesions among the 3 major coronary arteries, respectively. Moreover, our difficulty score for RCA CTO was superior to the J-CTO score in predicting unsuccessful PCI.

Clinical and angiographic differences might explain the discrepancies of success rates in CTO lesions among the 3 major coronary arteries. Our novel difficulty score was comparable to the J-CTO score in predicting unsuccessful CTO-PCI with a superior discriminatory capacity.

Endovascular recanalization in patients with symptomatic nonacute intracranial large artery occlusion (ILAO) has been reported to be feasible, but technically challenging. This study aimed to determine the predictors of successful endovascular recanalization in patients with symptomatic nonacute ILAO.

The outcomes of endovascular recanalization attempts performed in 70 consecutive patients showing symptomatic nonacute ILAO with hemodynamic cerebral ischemia between January 2016 to December 2022 were reviewed. Potential variables, including clinical and radiological characteristics related to technical success, were collected. Univariate analysis and multivariate logistic regression were performed to identify predictors of successful recanalization for nonacute ILAO.

Technically successful recanalization was achieved in 57 patients (81.4%). The periprocedural complication rate was 21.4% (15 of 70), and the overall 30-day morbidity and mortality rates were 7.1% (5 of 70) and 2.9% (2 of 70), respectively. Univariate analysis showed that successful recanalization was associated with occlusion duration, stump morphology, occlusion length, slow distal antegrade flow sign, and the presence of bridging collateral vessels. Multivariate analysis showed that occlusion duration ≤ 3 months (odds ratio [OR]: 22.529; 95% confidence interval [CI]: 1.636-310.141), tapered stump (OR: 7.498; 95% CI: 1.533-36.671), and occlusion length < 10 mm (OR: 7.049; 95% CI: 1.402-35.441) were independent predictive factors for technical success of recanalization.

Occlusion duration ≤ 3 months, tapered stump, and occlusion length < 10 mm were independent positive predictors of technical success of endovascular recanalization for symptomatic nonacute ILAO. These findings may help predict the likelihood of successful recanalization in patients with symptomatic nonacute ILAO and also provide a reference for the selection of appropriate patients. Further prospective and multicenter studies are required to validate our findings.

Chronic total occlusion (CTO) of the coronary arteries is a relatively common finding in routine coronary angiography. Of late, there has been considerable improvement in the success rate of percutaneous intervention for coronary CTO, attributed to technological advancement and skills development. CT coronary angiogram (CTCA) is a simple, non-invasive, and cost-effective test that aids in the diagnosis and management of coronary artery disease, including CTOs. The development of multi-slice CT and the use of 3D volume rendering images has revolutionised the diagnostic abilities of CTCA, with improvements in imaging quality and detailed anatomical and morphological characterisation of the plaque disease. In CTO percutaneous intervention, CTCA is used in pre-procedural planning, applying scoring systems to predict the likely success of the intervention as well as the post-procedural evaluation and follow-up. This review examines the different uses of CTCA in CTO intervention, its impact on successful recanalisation and the areas for future consideration.

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

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

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

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

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.

(1) Background: The probability of technical success in percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) represents essential information for specifying the priority of PCI for treatment selection in patients with CTO. However, the predictabilities of existing scores based on conventional regression analysis remain modest, leaving room for improvements in model discrimination. Recently, machine learning (ML) techniques have emerged as highly effective methods for prediction and decision-making in various disciplines. We therefore investigated the predictability of ML models for technical results of CTO-PCI and compared their performances to the results from existing scores, including J-CTO, CL, and CASTLE scores. (2) Methods: This analysis used data from the Japanese CTO-PCI expert registry, which enrolled 8760 consecutive patients undergoing CTO-PCI. The performance of prediction models was assessed using the area under the receiver operating curve (ROC-AUC). (3) Results: Technical success was achieved in 7990 procedures, accounting for an overall success rate of 91.2%. The best ML model, extreme gradient boosting (XGBoost), outperformed the conventional prediction scores with ROC-AUC (XGBoost 0.760 [95% confidence interval {CI}: 0.740-0.780] vs. J-CTO 0.697 [95%CI: 0.675-0.719], CL 0.662 [95%CI: 0.639-0.684], CASTLE 0.659 [95%CI: 0.636-0.681]; p < 0.005 for all). The XGBoost model demonstrated acceptable concordance between the observed and predicted probabilities of CTO-PCI failure. Calcification was the leading predictor. (4) Conclusions: ML techniques provide accurate, specific information regarding the likelihood of success in CTO-PCI, which would help select the best treatment for individual patients with CTO.

Major advances have been seen in techniques and devices for performing percutaneous coronary interventions (PCIs) for chronic total occlusions (CTOs), but there are limited real-world practice data from developing countries.

To report clinical and angiographic characteristics, procedural aspects, and clinical outcomes of CTO PCI performed at dedicated centers in Brazil.

Included patients underwent CTO PCI at centers participating in the LATAM CTO Registry, a Latin American multicenter registry dedicated to prospective collection of these data. Inclusion criteria were procedures performed in Brazil, age 18 years or over, and presence of CTO with PCI attempt. CTO was defined as a 100% lesion in an epicardial coronary artery, known or estimated to have lasted at least 3 months.

Data on 1196 CTO PCIs were included. Procedures were performed primarily for angina control (85%) and/or treatment of moderate/severe ischemia (24%). Technical success rate was 84%, being achieved with antegrade wire approaches in 81% of procedures, antegrade dissection and re-entry in 9%, and retrograde approaches in 10%. In-hospital adverse cardiovascular events occurred in 2.3% of cases, with a mortality rate of 0.75%.

CTOs can be treated effectively in Brazil by using PCI, with low complication rates. The scientific and technological development observed in this area in the past decade is reflected in the clinical practice of dedicated Brazilian centers.

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is associated with high incidence of complications. We queried PubMed and the Cochrane Library (last search: October 26, 2022) for CTO PCI-specific periprocedural complication risk scores. We identified 8 CTO PCI-specific risk scores: (1) Angiographic coronary artery perforation (OPEN-CLEAN [Outcomes, Patient Health Status, and Efficiency iN (OPEN) Chronic Total Occlusion (CTO) Hybrid Procedures - CABG, Length (occlusion), EF <50%, Age, CalcificatioN] perforation, c-statistic 0.75): previous coronary artery bypass graft surgery, occlusion length 20 to 60 mm or ≥60 mm, left ventricular ejection fraction (LVEF) <50%, age 50 to 70 years or ≥70 years, heavy calcification. (2) Major adverse cardiovascular events (MACE) (PROGRESS-CTO complication, c-statistic 0.76): age >65 years, lesion length ≥23 mm, retrograde strategy, and (3) MACE (PROGRESS-CTO MACE, c-statistic 0.74): age ≥65 years, female gender, moderate/severe calcification, blunt/no stump, anterograde dissection and re-entry (ADR) or retrograde strategy. (4) All-cause mortality (PROGRESS-CTO mortality, c-statistic 0.80): age ≥65, moderate/severe calcification, LVEF ≤45%, ADR or retrograde strategy. (5) Perforation requiring pericardiocentesis (PROGRESS-CTO pericardiocentesis, c-statistic 0.78): age ≥65 years, moderate/severe calcification, female gender, ADR or retrograde strategy. (6) Acute myocardial infarction (PROGRESS-CTO acute myocardial infarction, c-statistic 0.72): previous coronary artery bypass graft surgery, atrial fibrillation, blunt/no stump. (7) Perforation requiring any treatment (PROGRESS-CTO perforation, c-statistic 0.74): age ≥65 years, moderate/severe calcification, blunt/no stump, ADR, or retrograde strategy. (8) Contrast-induced acute kidney injury (c-statistic 0.84): age ≥75, LVEF <40%, serum creatinine >1.5 mg/100 ml, serum albumin ≤30, 30<albumin≤40 or >40 g/L. There are 8 CTO PCI periprocedural risk scores that may facilitate risk assessment and procedural planning in patients who underwent CTO PCI.

The impact of occlusion length on the procedural techniques and outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study.

We examined the clinical and angiographic characteristics and procedural outcomes of 10,335 CTO PCIs at 42 US and non-US centers between 2012 and 2022. The cohort was divided into two groups based on lesion length (≥20 mm vs. <20 mm).

Long lesions were present in 7208 (70%) patients. Comorbidities were more common in patients with long CTOs. Compared with short lesions, long lesions had higher J-CTO score (2.8 ± 1.1 vs. 1.3 ± 1; p < 0.001) and retrograde wiring was more often the initial (15.5% vs. 4.0%; p < 0.001) and successful (22.8% vs. 8.2%; p < 0.001) crossing strategy. Long lesions were more likely to require longer procedure (123 vs. 91 min; p < 0.001) and fluoroscopy (47.1 vs. 32.2 min; p < 0.001) time, larger contrast volume (218 vs. 200 mL; p < 0.001) and higher air kerma radiation dose (2.4 vs. 1.7 Gy; p < 0.001). After adjusting for potential confounders, long lesions were associated with lower technical success (odds ratio [OR]: 0.91 per 10 mm increase; 95% confidence interval [CI]: 0.88, 0.94) and higher major adverse cardiovascular events (MACE) (OR: 1.08 per 10 mm increase; 95% CI: 1.02, 1.15).

CTO PCI of long occlusions is independently associated with lower rates of technical success and higher rates of in-hospital MACE.

To develop a risk score model for primary spontaneous pneumothorax surgery (prolonged air leak or ipsilateral recurrence). The model was internally validated for risk estimation.

We analyzed 453 patients with primary spontaneous pneumothorax between 2014 and 2018. Patients were randomly assigned a 2:1 ratio to the development dataset (n = 302, study cohort) or the internal validation dataset (n = 151, validation cohort). The final outcomes of patients with primary spontaneous pneumothorax, the presence or absence of surgical indications, were tracked. Multivariable logistic regression models were prepared to estimate the probability of surgical indication and a scoring model was created. It was internally validated using the validation cohort. Calibration was ascertained using the Hosmer-Lemeshow method and Brier score.

The surgery indication rate was 47.8% (n = 217) (prolonged air leak, n = 130; ipsilateral recurrence, n = 87). There were no demographic or radiological differences between the validation and the study cohorts. Logistic regression analysis showed that the presence of bullae or blebs (p < 0.001, odds ratio = 3.340, 95%CI = 1.753-6.363) and pneumothorax volume (p < 0.001, odds ratio = 1.033, 95%CI = 1.019-1.048) were independent risk factors for surgical indication. The scoring model significantly predicted surgical indications (area under the curve, AUC = 0.768, 95%CI = 0.714-0.821, p < 0.001). Our model showed acceptable discrimination with an AUC > 0.75 in the validation set (AUC = 0.777, 95%CI = 0.702-0.852, p < 0.001) and had an adequate calibration (Hosmer-Lemeshow test p = 0.249, Brier score = 0.25).

The internally validated primary spontaneous pneumothorax scoring model was a good predictor of the need for surgery in patients with primary spontaneous pneumothorax. Prospective external validation studies with larger patient cohorts are required.

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.

This study aimed to investigate the association between the perivascular fat attenuation index (FAI) and the success of the antegrade percutaneous coronary intervention (PCI) for chronic total occlusion (CTO).

This study evaluated patients with only one CTO lesion observed on conventional coronary angiography (CAG) who underwent coronary computed tomography angiography (CCTA) < 1 month before CAG, from 2018 to 2019. The clinical data, CCTA-based CTO lesion morphologic characteristics, and perivascular FAI of CTO lesions were recorded and analysed.

In total, 156 patients with CTOs were enrolled in this study. Successful antegrade PCI (A-PCI) was achieved in 105 CTO lesions (67.3%). The perivascular FAI of the failed A-PCI group was significantly lower than the successful A-PCI group (-84.76 ± 10.44 Hounsfield unit (HU) vs. -67.54 ± 9.94 HU; p < 0.001), and the cut-off value determined by the receiver operating characteristic (ROC) curve was -77.50 HU. Multivariable analysis revealed no statistical significance in the clinical data, FAI ≤ -77.50 HU (odds ratio (OR): 33.96), negative remodeling (OR: 4.36), severe calcification degree (OR: 4.43) and occlusion length ≥ 20.25 mm (OR: 3.89) were independent predictors of A-PCI failure. The prediction performance of combining the three morphologic characteristics (severe calcification, occlusion length ≥ 20.25 mm, and negative remodeling) with FAI ≤ -77.50 HU was better than that of the three morphologic characteristics alone (0.93 versus 0.77, p < 0.001).

As a non-invasive index for detecting coronary inflammation, FAI complements indicators based on coronary CTA well and may be helpful for choosing appropriate interventional strategies.

• Perivascular FAI of CTO was significantly higher in the failed A-PCI group. • The combination of FAI with other morphological predictors showed higher predictive performance of failed A-PCI for CTOs. • FAI is a good complement to indicators based on coronary CTA.

Although the Japanese chronic total occlusion (J-CTO) score is widely used to assess the complexity of revascularization for CTO lesions, ambiguous and conflicting results are reported in validation studies. Therefore, we aimed to quantitatively evaluate the effectiveness of the J-CTO score and explore the heterogeneity of its comparison with other CTO scores.

PubMed, Embase, the Cochrane Library, and ClinicalTrials.gov databases were systematically searched from January 1st, 2011 to December 23rd, 2021. Studies that examined the accuracy of the J-CTO score were eligible. Where feasible, estimates of discrimination and calibration were pooled with a random-effects model. The Prediction model Risk Of Bias ASsessment Tool (PROBAST) was used for risk-of-bias assessment. This study was reported according to PRISMA guidelines and prospectively registered with PROSPERO (CRD42019126161).

Of 28 included studies (N = 34,944 lesions), 24 were eligible for meta-analysis. The J-CTO score demonstrated significant discrimination for 30-min wire crossing (summary C-statistic 0.76; 95% CI 0.68-0.84) and technical success (0.68; 95% CI 0.61-0.74) despite significant heterogeneity. Only 19 (33%) of the 58 pairwise comparisons with 14 competing scores that were based on discrimination reported a statistical result. The J-CTO score performed worse (relative difference of C-statistics >5%) in eight out of 33 independent comparisons but better in another 13. Methodological shortcomings resulted from only one study evaluating model calibration appropriately.

The discrimination power of the J-CTO score was useful for time-efficient wire crossing and moderate for angiographic success. Head-to-head comparisons of CTO scores would benefit from standardized reporting and appropriate statistical methods.Key messagesThe J-CTO score has useful discrimination in predicting 30-min wire crossing while performing moderately for technical success.After excluding optimism bias, there is insufficient independent evidence supporting the superiority of newly introduced models over the J-CTO score.Standardized methodology and assessment are needed to achieve a better understanding of CTO scores, especially for their calibration.

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.

To investigate a scoring system for predicting the risk of successful percutaneous coronary intervention (PCI) after prior failed chronic total occlusion (CTO). Patients with previously attempted CTO-PCI were enrolled in our study retrospectively from January 2016 to December 2019. All clinical and procedural data were collected and analyzed. Univariate and multivariate logistic regression was performed to investigate the predictors of technical success. A total of 194 patients/CTO lesions were studied. The multivariate logistic regression showed that occlusion length < 20 mm (odds ratio (OR) = 2.94, score = 1), non-calcification (OR = 2.93, score = 1), adequate distal landing zone (OR = 4.46, score = 1), Rentrop grade ≥ 2 (OR = 5.98, score = 1), and retrograde approach as the initial strategy (OR = 10.28, score = 2) were predictors of the success of re-attempt PCI. The technical success rate for scores from 0 to ≥ 4 were 0%, 17.9%, 46.2%, 77.8%, and 93.3% respectively. Our scoring system can be used to predict the success rate of re-attempt CTO-PCI.