Algorithmic solutions to common problems encountered during chronic total occlusion angioplasty: The algorithms within the algorithm

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.

A non-interventional cardiologist's guide to coronary chronic total occlusions

Coronary chronic total occlusions (CTO) are present in up to one-third of patients with coronary artery disease (CAD). It is thus essential for all clinical cardiologists to possess a basic awareness and understanding of CTOs, including optimal evaluation and management. While percutaneous coronary intervention (PCI) for CTO lesions has many similarities to non-CTO PCI, there are important considerations pertaining to pre-procedural evaluation, interventional techniques, procedural complications, and post-procedure management and follow-up unique to patients undergoing this highly specialized intervention. Distinct from other existing topical reviews, the current manuscript focuses on key knowledge relevant to non-interventional cardiologists.

Applicability of J-CTO channel score to predict microcatheter tracking during retrograde percutaneous coronary intervention of chronic total occlusions: Insights from the SURFING MICRO registry

BACKGROUND

The J-chronic total occlusion (CTO) channel score can predict guidewire tracking of the collateral channels (CCs), but its efficacy in predicting microcatheter tracking has never been tested in the setting of retrograde CTO-percutaneous coronary intervention (PCI).

AIMS

Predicting microcatheter collateral tracking during retrograde CTO-PCIs.

METHODS

A total of 189 patients undergoing retrograde CTO-PCI from April 2017 to August 2021 were screened. The primary outcome of interest was a correlation between J-CTO channel score and microcatheter tracking failure (MTF) after successful CC tracking by the guidewire. The independent association between anatomical features of the J-CTO channel score and the primary outcome of interest was explored.

RESULTS

After adjustment, only small size (adjusted OR: 12.70, 95% confidence interval [CI]: 1.79-89.82; p = 0.01) and continuous bends (adjusted OR: 14.15, 95% CI: 2.77-72.34; p < 0.001) remained significantly associated with an increased risk of MTF for septal collaterals. The small size was the only predictor of the MTF for epicardial collaterals (OR: 6.39, 95% CI: 1.13-35.96; p = 0.020) at univariate analysis. Patients in the MTF group had a lower incidence of procedural success compared with patients in the microcatheter tracking success (MTS) group (40.0% vs. 93.9%, p < 0.001) and had a higher incidence of collateral perforations (20.0% vs. 3.0%, p < 0.001).

CONCLUSION

Small and tortuous septal collaterals, identified by a score ≥3, are associated with an increased risk of MTF, lower incidence of procedural success, and higher risk of procedural complications driven by collateral perforations.

Contemporary In-Hospital Outcomes of Chronic Total Occlusion Percutaneous Coronary Interventions: Insights from the MENATA (Middle East, North Africa, Turkey, and Asia) Chapter of the PROGRESS-CTO Registry

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has been rapidly evolving in different parts of the world. We examined the clinical and angiographic characteristics and procedural outcomes of 1,079 consecutive CTO PCIs performed in 1,063 patients at 10 centers in the Middle East, North Africa, Turkey, and Asia regions between 2018 and 2022. The mean age was 61 ± 10 years and 82% of the patients were men. The prevalence of diabetes (49%) and previous PCI (50%) was high. The most common target vessel was the right coronary artery (51%), followed by the left anterior descending artery (33%) and the circumflex artery (15%). The mean Japanese CTO score was 2.1 ± 1.2 and mean PROGRESS-CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention) score was 1.2 ± 1.0. The technical and procedural success rates were high (91% and 90%, respectively) with a low incidence (1.6%) of in-hospital major adverse cardiac events. The incidence of perforation was 4.6% (n = 50): guidewire exit was the most common mechanism of perforation (48%) and 14 patients required pericardiocentesis (28%). Antegrade wire escalation was the most common crossing strategy used (91%), followed by retrograde approach (24%) and antegrade dissection and re-entry (12%). Median contrast volume, air kerma radiation dose, and fluoroscopy time were 300 (200 to 400) ml, 3.7 (2.0 to 6.3) Gy, and 40 (25 to 65) minutes, respectively. In conclusion, high success and acceptable complication rates are currently achieved at experienced centers in the Middle East, North Africa, Turkey, and Asia regions using a combination of crossing strategies.

Balloon-assisted subintimal entry (BASE) in chronic total occlusion percutaneous coronary interventions

BACKGROUND

There is limited data on the use of the balloon-assisted subintimal entry (BASE) technique in chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

METHODS

We analyzed the baseline clinical and angiographic characteristics and outcomes of 155 CTO PCIs that utilized the BASE technique at 31 US and non-US centers between 2016 and 2023.

RESULTS

The BASE technique was used in 155 (7.9%) of 1968 antegrade dissection and re-entry (ADR) cases performed during the study period. The mean age was 66 ± 10 years, 88.9% of the patients were men, and the prevalence of diabetes (44.6%), hypertension (90.5%), and dyslipidemia (88.7%) was high. Compared with 1813 ADR cases that did not use BASE, the target vessel of the BASE cases was more commonly the RCA and less commonly the LAD. Lesions requiring BASE had longer occlusion length (42 ± 23 vs. 37 ± 23 mm, p = 0.011), higher Japanese CTO (J-CTO) (3.4 ± 1.0 vs. 3.0 ± 1.1, p < 0.001) and PROGRESS-CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention chronic total occlusion) (1.8 ± 1.0 vs. 1.5 ± 1.0, p = 0.008) scores, and were more likely to have proximal cap ambiguity, side branch at the proximal cap, blunt/no stump, moderate to severe calcification, and proximal tortuosity. Technical (71.6% vs. 75.5%, p = 0.334) and procedural success (71.6% vs. 72.8%, p = 0.821), as well as major adverse cardiac events (MACE) (1.3% vs. 4.1%, p = 0.124), were similar in ADR cases that used BASE and those that did not.

CONCLUSIONS

The BASE technique is used in CTOs with longer occlusion length, higher J-CTO score, and more complex angiographic characteristics, and is associated with moderate success but also low MACE.

Role of the retrograde Carlino technique for chronic total occlusion percutaneous coronary intervention

BACKGROUND

There is scarce data on the outcomes of the Carlino technique for chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We aimed to investigate the indications and outcomes of the Carlino technique as performed in the context of the retrograde approach.

METHODS

We pooled CTO PCI cases where a retrograde Carlino technique was performed from high-volume operators at four centers. The Carlino technique was characterized according to its indication (achieving plaque/cap modification, clarifying microcatheter location within the vessel, resolving distal cap ambiguity) and was considered successful when it led to the desired outcome.

RESULTS

A total of 43 patients were included. Occlusion complexity was very high (mean J-CTO score 3.3 ± 0.8). The two most common indications were understanding the anatomy of the occlusion and clarifying gear location (37.2%) and impenetrable distal cap (34.9%). The Carlino technique was successful in 88.4% of cases. Overall technical and procedural success was 86.0%. The most common successful crossing technique was reverse controlled antegrade and retrograde subintimal tracking (70.3%). No complications were attributed to the Carlino technique.

CONCLUSIONS

We observed a high success rate of the retrograde Carlino technique, as well as overall technical and procedural success rates. No Carlino technique-related complications were observed. Additional data from larger registries are warranted to further confirm the safety and efficacy of this technique.

Contemporary Issues in Chronic Total Occlusion Percutaneous Coronary Intervention

Remarkable progress has been achieved in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in recent years, with refinement of the indications and technical aspects of the procedure, imaging, and complication management. Randomized controlled trials and rigorous prospective registries have provided high-quality data on the benefits and risks of CTO PCI. Global collaboration has led to an agreement on nomenclature, indications, endpoint definition, and principles of clinical trial design that have been distilled in global consensus documents such as the CTO Academic Research Consortium. Increased use of preprocedural coronary computed tomography angiography and intraprocedural intravascular imaging, as well as development of novel techniques and structured CTO crossing and complication management algorithms, allow a systematic, stepwise approach to this difficult lesion subset. This state-of-the-art review provides a comprehensive discussion about the most recent developments in the indications, preprocedural planning, technical aspects, complication management, and future directions of CTO PCI.

The Impact of Calcium on Chronic Total Occlusion Management

Coronary artery calcification is prevalent in chronic total occlusions (CTO), particularly in those of longer duration and post-coronary artery bypass. The presence of calcium predicts lower procedural success rates and a higher risk of complications of CTO percutaneous coronary intervention. Adjunctive imaging, including pre-procedural computed tomography and intracoronary imaging, are useful to understand the distribution and morphology of the calcium. Specialised guidewires and microcatheters, as well as penetration, subintimal entry and luminal re-entry techniques, are required to cross calcific CTOs. The use of both atherectomy devices and balloon-based calcium modification tools has been reported during CTO percutaneous coronary intervention, although they are limited by concerns regarding safety and efficacy in the subintimal space.

Preprocedure Planning for Chronic Total Occlusion Percutaneous Coronary Intervention: The Separation Is in the Preparation

To perform chronic total occlusion percutaneous coronary intervention safely, efficiently, and successfully, adequate time must be dedicated to thorough preprocedural planning. This process should encompass a patient encounter, becoming fully familiarized with the patient's clinical traits, a detailed review of coronary anatomy, laying out an algorithmic procedural approach and making any relevant plans for actions that will enhance intraprocedural safety.

The Hybrid Approach and Its Variations for Chronic Total Occlusion Percutaneous Coronary Intervention

Selected patients with coronary chronic total occlusion (CTO) benefit with respect to symptoms, quality of life, ischemia reduction, and potentially longevity among other benefits. CTO lesions tend to be the most technically challenging for practicing interventional cardiologists to deliver a successful and safe result and clinical experience for a given patient. The Hybrid algorithm for CTO percutaneous coronary intervention and the subsequent subalgorithms for focused technical challenges have a standardized process and provide a consistent platform for optimized patient care, medical education, and clinical investigation in patients challenged with total occlusion and complex coronary disease.

Retrograde Dissection and Reentry: Strategies: Common Pitfalls and Troubleshooting

The retrograde dissection reentry (RDR) technique is often required to treat the most complex chronic total occlusions (CTOs). This involves a sequence of procedural steps with many potential pitfalls. Procedural planning, knowledge of the equipment, including task-specific wires and microcatheters, and the ability to systematically trouble shoot is necessary to achieve consistent success. With the combination of more complex anatomy and collateral crossing, RDR is associated with higher rates of procedural complications, which the CTO operator must be specifically trained to avoid and to manage.

Toolbox for Coronary Chronic Total Occlusion Percutaneous Coronary Intervention

Since the publication of the hybrid algorithm there has been rapid development of new specialty wires, microcatheters, guide extensions, and low-profile balloons to facilitate successful coronary chronic total occlusion percutaneous coronary intervention. With development of new devices, it is best to categorize them by design and intended task. This enables a safe and systematic approach to coronary chronic total occlusion percutaneous coronary intervention and avoid overlap and waste. This article serves as a guide for tool selection for the interventional cardiologist performing coronary chronic total occlusion percutaneous coronary intervention.

Algorithms for challenging scenarios encountered in transradial intervention

Transradial intervention (TRI) was first introduced by Lucien Campeau in 1989 and since then has created a lasting impact in the field of interventional cardiology. Several studies have demonstrated that TRI is associated with fewer vascular site complications, offer earlier ambulation and greater post-procedural comfort. Patients presenting with ST Segment Elevation Myocardial Infarction (STEMI) have experienced survival benefit and higher quality-of-life metrics as well with TRI. While both the updated scientific statement by the American Heart Association and the 2017 European Society of Cardiology guidelines recommend a “radial first” approach there appears to be a lag in physicians adapting TRI as the preferred vascular access. We present a review focusing on identification and management of TRA related challenges and complications using a systematic algorithmic approach.

Successful revascularization of right coronary artery chronic total occlusion by the antegrade and retrograde approaches

The treatment of chronic total occlusion (CTO) of coronary arteries allowed for a remarkable improvement in success rates and is represented by the introduction of the "Hybrid algorithm". An inability to cross the occlusion with a guidewire is the most common cause of failure of CTO revascularization. As antegrade options are limited, intervention upon the extreme angulation of the coronary artery warrants a retrograde approach. Here, we report a 58-year-old man with symptoms of effort angina complicated with three-vessel disease and CTO of the right coronary artery (RCA). Left main artery bifurcation lesions were treated with systematic two-stent strategies and intervention upon RCA CTO after three months by means of a combination of the antegrade and retrograde approaches. The RCA was eventually revascularized by the implantation of stents, and no adverse events were observed during hospitalization.