CTO PCI Research Articles

Machine learning prediction models for individualized technical success of chronic total occlusion revascularization using anatomical input

Abstract Introduction Chronic total occlusion revascularization (CTO PCI) remains a challenging procedure in the realm of percutaneous coronary interventions. Efforts such as implementing the hybrid algorithm for CTO crossing have been made. Interventional techniques are evolving, and complexity scores such as the J-CTO score might get outdated. Machine learning models can be used to overcome this limitation by constantly providing new data and improving the models by continuous data feeding. In this study, we introduced machine learning models to predict individualized technical success of CTO PCI using anatomical coronary information and baseline information. Methods Consecutive patients undergoing percutaneous coronary intervention of chronic total occlusions were enrolled in this study. Angiographic data and lesion characteristics from coronary angiography were extracted. Machine learning models were applied to predict technical success. A total of 271 patients were used to validate and train the models and 50 separate patients for testing. Data was normalized and fed to several classifying machine learning models including decision trees (DT), random forest (RF), extreme gradient boosting (XGB), CatBoost (CB) classifiers, and light gradient boosting (LGB). Finally, accuracy, precision, recall and F1-score of the selected hyperparameters and cross-validation was performed. Results CB was the best performing model with an accuracy of 0.81, precision of 0.83 and recall of 0.98. The F1 score was 0.90. RF was the second-best performing model with accuracy of 0.77, precision of 0.82, recall of 0.92 and F1 score 0.87. The tuned models performed modestly with RF having a low F1 score of 0.44, due to small sample size. In the tuned models. LGB had a higher F1 score and a relatively high accuracy (0.782) and precision (0.508). The feature importance matrix found age, CTO length, reference diameter to have the highest value among the lesion complexity parameters. Discussion: Overall, the normal-run CB was the best model for predicting the technical success after a CTO PCI with a high accuracy. The fine-tuned and cross-validated models performed modestly because of the relatively small, unbalanced dataset and overfitting. However, data showed promising first results in implementing machine learning into predicting interventional outcomes. Further studies like data augmentation and providing a weighted dataset would increase the model performance and provide a very precise statement whether a patient would have increased chances to have a successful PCI based on baseline anatomic information. Conclusion This is one of the first studies to predict technical success of CTO PCI using angiographic baseline parameters using machine learning. Future studies with larger patient cohorts are needed to involve deploying the selected model in larger patient cohorts including external validation and assessing its performance with new, unseen data.Figure 1.Machine learning modelsFigure 2.Feature importance matrix

Ten tips and tricks for successful distal true lumen wiring from three-dimensional wiring experts.

Antegrade wiring is the dominant method used in chronic total occlusion percutaneous coronary intervention (CTO PCI). However, distal cap puncture for distal true lumen wiring remains a significant barrier toward success. Three-dimensional (3D) fluoroscopic wiring can improve the speed, safety, and success of distal cap wiring. In this article, we provide 10 tips for every CTO interventionist to use when performing 3D wiring in distal true lumen wiring.

Innovative Strategies for Chronic Total Occlusions

CHRONIC total occlusion percutaneous coronary intervention (CTO PCI) strategies were thoroughly discussed at the EuroPCR 2024 Annual Global Course in Paris, France. Experts in the field gathered to discuss the advantages and limitations of various approaches, including the use of intravascular ultrasound (IVUS) when locating ambiguous proximal caps. Experts discussed several techniques in the context of success rate and patient safety, with a focus on what changes can be made to current guidelines to ultimately improve patient outcomes in high-risk cases.

Innovative Strategies for Chronic Total Occlusions

CHRONIC total occlusion percutaneous coronary intervention (CTO PCI) strategies were thoroughly discussed at the EuroPCR 2024 Annual Global Course in Paris, France. Experts in the field gathered to discuss the advantages and limitations of various approaches, including the use of intravascular ultrasound (IVUS) when locating ambiguous proximal caps. Experts discussed several techniques in the context of success rate and patient safety, with a focus on what changes can be made to current guidelines to ultimately improve patient outcomes in high-risk cases.

TCTAP A-002 Exploring the Success Rate in CTO PCI: Bayesian Approach for Preprocedural Inference and Intraprocedural Revising

TCTAP A-002 Exploring the Success Rate in CTO PCI: Bayesian Approach for Preprocedural Inference and Intraprocedural Revising

Coronary wire entrapment and unraveling during CTO PCI - how to retrieve a filament from the aorta.

Coronary wire entrapment and unraveling during CTO PCI - how to retrieve a filament from the aorta.

Prevention of Coronary Artery Perforation and Its Treatment During CTO PCI: Study of Effective Coiling for Distal and Collateral Perforations

Prevention of Coronary Artery Perforation and Its Treatment During CTO PCI: Study of Effective Coiling for Distal and Collateral Perforations

Ostial Left Anterior Descending Artery Chronic Total Occlusion - Left Main Coronary Artery Intramural Hematoma

Chronic total occlusion intervention of ostial left anterior descending artery lesion without clear cap poses challenges for wiring. Intravascular ultrasound guided antegrade cap puncture and guide extension assisted reverse controlled antegrade and retrograde tracking away from ostium would minimize inflow injuries. This case report explores inflow injury and its detection by imaging in ostial LAD CTO PCI.

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

ObjectiveWhile 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. MethodsThis 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. ResultsA 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. ConclusionsNo 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.

"Crossing the invisible".

Key Points Using the septal collaterals without angiographic connection during retrograde CTO PCI was associated with high collateral channel crossing rate (>80%). Two predicators for channel crossing failure were shorter posterior descending artery (less than 2/3 of the distance to cardiac apex) and well developed non‐septal collateral. Further studies focusing on retrograde channel selection could improve the success rate and safety of retrograde CTO PCI.

Utilization of intravascular imaging in elective non chronic total occlusion percutaneous intervention and chronic total occlusion percutaneous intervention: Trends in utilization and impact on in-hospital mortality

ObjectivesThe objectives of this retrospective study include outcomes associated with and without intravascular imaging in cases of elective single vessel (SV) CTO PCI and in non-CTO PCI. MethodWe explored the NIS database from October 1, 2015 to December 31, 2018 to identify 317,090 adult admissions with elective SV PCI. Admissions with STEMI and NSTEMI were excluded to identify elective cases only. Using the ICD 10 diagnosis code for CTO, we identified 33,345 admissions that underwent SV CTO PCI. We classified the remaining cases as SV non-CTO PCI. ResultsIntravascular imaging was utilized in 2930 (8.8%) cases in CTO PCI group and 23,710 (8.3%) cases in non-CTO PCI groups. The utilization of intravascular imaging (IVUS/OCT) significantly increased in elective SV CTO PCI, 6.4%–11.2%, p-trend<0.001 and non-CTO PCI group, 7.3%–9.0%, p-trend<0.001. There was no significance difference in mortality with and without intravascular imaging (combined IVUS/OCT vs no IVUS/OCT: 1.5% vs 1.3%, p = 0.195) in the CTO PCI group. But, in non-CTO PCI admissions, there was a significantly lower in-hospital mortality when intravascular imaging was used (0.7% vs 0.8%, p = 0.003). The cost of hospitalization was significantly higher when intravascular imaging was used in elective single vessel CTO PCI admissions, combined IVUS/OCT vs no IVUS/OCT: $27,427 vs $21,452, p < 0.001 and non-CTO PCI admissions, combined IVUS/OCT vs no IVUS/OCT: $23,620 vs $20,272, p < 0.001. ConclusionsIn conclusion, despite the cost, intravascular imaging use decrease mortality in non-CTO PCI groups but there is no difference in mortality in CTO PCI groups.

Is there a woman paradox? Commentary on the Gender differences in percutaneous coronary intervention for chronic total occlusions from the ERCTO study.

Key Points Women are underrepresented in CTO revascularisation registries and trials. Women undergoing CTO PCI have lower J‐CTO scores, higher procedural success with no difference in MACC, but more complications such as perforations, vascular complications and major bleeding. There is a need for more large‐scale sex‐based analyses enrolling more women, with complex CTO lesion subsets and the adoption of contemporary best practices for CTO PCI.

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.

Scores and algorithms in CTO PCI: "PROGRESS" or an exercise in futility?

Scores and algorithms in CTO PCI: "PROGRESS" or an exercise in futility?

Chronic Total Occlusion Interventions in Patients with Reduced Ejection Fraction.

The goal of this paper is to review the current evidence surrounding CTO PCI in patients with low EF, the most high-risk population to treat. We also present pertinent case examples and offer practical tips to increase success and lower complications when performing CTO PCI in patients with low EF. In a prospective randomized control study, greater improvement in angina frequency and quality of life, assessed by the Seattle Angina Questionnaire, was achieved by CTO PCI compared to optimal medical therapy. Furthermore, after successful CTO PCI, improvements in health status were similar in patients with both low and normal EF. CTO PCI can not only ameliorate symptoms of angina in patients with low EF but may also potentially improve EF in carefully selected populations. However, information regarding treatment of this high-risk population is lacking and large-scale studies targeting patients with severely reduced EF remain necessary.

Patient Selection and Clinical Indication for Chronic Total Occlusion Revascularization-A Workflow Focusing on Non-Invasive Cardiac Imaging.

Percutaneous coronary intervention of chronic total occlusion (CTO PCI) is a challenging procedure with high complication rates and, as not yet fully understood long-term clinical benefits. Ischemic symptom relief in patients with high ischemic burden is to date the only established clinical indication to undergo CTO PCI, supported by randomized controlled trials. In this context, current guidelines suggest attempting CTO PCI only in non-invasively assessed viable CTO correspondent myocardial territories, with large ischemic areas. Hence, besides a comprehensive coronary angiography lesion evaluation, the information derived from non-invasive cardiac imaging techniques is crucial to selecting candidates who may benefit from the revascularization of the occluded vessel. Currently, there are no clear recommendations for a non-invasive myocardial evaluation or choice of imaging modality pre-CTO PCI. Therefore, selecting among available options is left to the physician's discretion. As CTO PCI is strongly recommended to be carried out explicitly in experienced centers, full access to non-invasive imaging for risk-benefit assessment as well as a systematic institutional evaluation process has to be encouraged. In this framework, we opted to review the current myocardial imaging tools and their use for indicating a CTO PCI. Furthermore, based on our experience, we propose a cost-effective systematic approach for myocardial assessment to help guide clinical decision-making for patients presenting with chronic total occlusions.

806 BRIDGING COLLATERALS OF CHRONICALLY OCCLUDED LEFT INTERNAL MAMMARY ARTERY BYPASS GRAFT TO LEFT ANTERIOR DESCENDING ARTERY

Abstract Methods and results The internal mammary artery (IMA) is the conduit of choice to bypass the left anterior descending (LAD) coronary artery in patients eligible for coronary artery bypass grafting (CABG). In case of graft occlusion, it is still not clear whether it is better to revascularize the graft or the recipient native vessel, on top of optimal medical therapy. A 55-year-old man, with prior CABG, underwent urgent coronary angiography for an acute coronary syndrome. LAD CTO, severe proximal circumflex artery stenosis, and mild atherosclerosis of the right coronary artery were found. Moreover, a proximal occlusion of the venous graft to the obtuse marginal branch and LIMA CTO within the body of the graft were shown as well. Surprisingly, many well-developed bridging collaterals, arising close to the proximal cap of the LIMA occlusion, supplied the bloodstream circulation distal to the occlusion within the LIMA. At that time, a left main–proximal circumflex artery stenting was performed (3.5×24-mm Xience Sierra, Abbott) because that was judged the culprit lesion. One month later the patient still complained of effort angina and dyspnoea despite optimized antianginal medical therapy. The patient was scheduled for elective antegrade LIMA CTO PCI, considered the most appropriate treatment strategy. Indeed, the presence of a prior stent implanted in the left main– circumflex artery would have made difficult a proximal cap negotiation and its penetration by guidewires in case of antegrade LAD CTO PCI. Thus, the LIMA CTO negotiation was initially attempted with a Fielder FC guidewire (Asahi Intecc) and a supporting Corsair Pro (Asahi Intecc) microcatheter. The polymeric soft wire prolapsed preferentially into the bridging collaterals without the chance to engage the CTO proximal cap. Finally, a moderate-weight hydrophilic GAIA second (Asahi Intecc) succeeded in cap penetration and final CTO crossing. After lesion predilatation with a 2.0×15-mm balloon (Emerge, Boston Scientific), 2 overlapped stents, respectively 2.75×44 mm and 3.0×18 mm (VIVO ISAR, Translumina) were deployed and postdilated by a 3.0×15-mm non-compliant balloon (Accuforce, Terumo). The final result was deemed very satisfactory with a TIMI 3 flow. Conclusions Many studies showed that IMA has active biological functions, providing a sort of protection against atherosclerosis and self-reparative properties. These biological properties might justify the IMA high long-term patency rates as CABG conduits. The development of bridging collaterals in this patient, represents a clear proof of the LIMA self-reparative properties. Whereas bridging collaterals are a common feature of coronary CTO, their development in a LIMA bypass graft represents a unique finding which requires further investigation.

Abstract 11771: Impact of Overweight/Obesity/Higher Body Mass Index on Long-Term Major Adverse Cardiac Outcomes Following Chronic Total Occlusion-Percutaneous Coronary Interventions- A Systematic Review and Meta-Analysis

Background: Obesity is usually associated with worse cardiovascular outcomes. However, fewer studies have evaluated its impact on long-term major adverse cardiovascular events (MACE) following CTO PCI. We conducted a meta-analysis to assess the same. Methods: PUBMED, Scopus, and EMBASE were systematically searched for studies reporting long-term (at least &gt;1 year) outcomes with obesity vs no obesity in patients with CTO PCI. MACE events [all-cause mortality, cardiac mortality, revascularization, restenosis/reocclusion, recurrent angina pectoris (RAP), target-vessel myocardial infarction (MI), heart failure, cardiac death, or ischemia-driven target-vessel revascularization (TVR) were the primary endpoint. Pooled odds ratios (OR) and heterogeneity were assessed with random-effects models and I2 statistics respectively. Subgroup analysis was performed to assess the risk by age group and follow-up duration. The leave-one-study-out method was used for sensitivity analysis. Results: After an initial electronic search of thirty-two studies, five studies were selected, and between 2016 to 2021 selected were included in the final analysis. The sample size consisted of 5022 patients with a median age of 63. No significant impact of higher BMI/obesity was seen overall on a median duration of 2.6 yrs [OR(95% CI)= 0.95 (0.82-1.11), p=0.53, I 2 = 90.86%)] (Fig 1). However, on a subgroup analysis, the geriatric age group (≥65 yrs) demonstrated an "Obesity Paradox" effect on MACE after CTO PCI, [OR (95%CI)=0.64 (0.47-0.88), I 2= 42.13, p&lt;0.01]. There was no difference in a subgroup analysis based on follow-up duration (≥3 years [OR (95%CI)=0.73 (0.42-1.27)] vs &lt;3 years OR (95%CI)=1.04 (0.84-1.27)]. Conclusions: Although higher BMI/obesity was not associated with overall long-term MACE in CTO PCI, the subgroup analysis demonstrated the "Obesity Paradox" (protective) effect in studies with a predominantly geriatric population.

Abstract 11623: Retrograde Facilitated Antegrade Dissection and Re-Entry

History: A 69-year-old man presented with severe medically refractory stable angina and was referred for revascularization of a right coronary artery (RCA) chronic total occlusion (CTO Figure 1.A ). The patient had undergone coronary artery bypass surgery 16 years prior as well as numerous percutaneous coronary intervention. Echocardiography demonstrated normal left ventricular systolic function. Procedure: Antegrade wiring was attempted first with a Fielder XT guidewire (GW) and a Turnpike Spiral microcatheter (MC Figure 1.B ). Due to the ambiguous proximal cap and long occlusion length, retrograde crossing was attempted next. After attempting to cross multiple collaterals a Sion Black crossed a proximal septal collateral ( Figure 1.C ), but several MCs could not follow the GW, despite ballooning the collateral with a 1.5 mm balloon and GuideLiner support. We switched to antegrade dissection and re-entry with a knuckled Gladius Mongo that reached the distal RCA ( Figure 1.D ). With the Stingray balloon and ‘double blind stick and swap’ technique we crossed into the distal true lumen, but the GW position was lost after removal of the balloon. We crossed with the retrograde GW to the antegrade guide catheter (Figure 1.E) , but ‘tip in’ technique as well as passing the retrograde MC was not successful. Using a new Stingray balloon and the retrograde GW as true lumen marker ( Figure 1.F ) we crossed into the distal true lumen. After drug-eluting stent implantation ( Figure 1.G ) the distal bifurcation was recanalized with kissing balloon dilation ( Figure 1.H ) and implantation of another stent with a nice final result ( Figure 1.I ). Conclusion: Persistence is key in CTO PCI in patients with severe medically refractory stable angina and limited revascularization options. Crossing the collaterals with MC can be challenging: possible solutions are smaller MC, predilation in septal collateral, ‘tip in’ or switching to another crossing strategy such as ADR with retrograde facilitation.

The predictive value of the triglyceride—glucose index for cardiovascular events in patients with coronary chronic total occlusion

BackgroundChronic total occlusion (CTO) of the coronary artery is a difficult problem in clinical practice. The triglyceride–glucose (TyG) index is an effective risk predictor of cardiovascular risk. However, the relationship between the TyG index and the prognosis of CTO patients remains unstudied. Thus, the present study aimed to investigate the relationship between the TyG index and cardiovascular risk in CTO patients.MethodsThis was a single-centre, retrospective cohort study. We retrospectively enrolled 652 patients with CTO lesions diagnosed by angiography and who underwent revascularization through PCI. Patients were routinely followed up for 24 months unless meeting the endpoint. The primary endpoint was the composite of all-cause death, nonfatal myocardial infarction, unplanned revascularization, and nonfatal ischaemic stroke. To test the association of the TyG index with cardiovascular risk, the categorized TyG index and Cox proportional hazards regression models were utilized.ResultsA total of 652 patients were enrolled in the final analysis (male: 83.7%, age: 58.2 ± 10.49 years). The average TyG index was 8.8 ± 0.57. CTO PCIs were procedurally successfully completed in 503 (77.15%) patients. During the follow-up period of 22.8 ± 3.84 months, 73 (11.19%) major adverse cardiovascular and cerebral events (MACCEs) occurred. When fully adjusted, there was a 2.09-fold risk for MACCEs among patients with the highest TyG index compared with those with the lowest TyG index [T2 vs. T1: hazard ratio (HR) 1.24, 95% confidence interval (CI) 0.65–2.38, P = 0.057; T3 vs. T1: HR 2.09, 95% CI 1.14–3.86, P = 0.018; P for trend = 0.036]. The restricted cubic spline (RCS) analysis showed that the HR for MACCEs increased as the TyG index increased over 8.71 [HR per standard deviation (SD) 1.740, 95% CI 1.23–2.46, P = 0.002]. The risk of MACCEs increased with increasing tertiles of TyG index in successful CTO PCI patients and nondiabetes mellitus (DM) patients (P < 0.05) but not in patients with failed CTO PCI and DM patients.ConclusionThe study revealed that the TyG index had significant relevance to cardiovascular risk in CTO patients and suggests that the TyG index is feasible for predicting cardiovascular risk in CTO patients.