Impact of Subintimal or Plaque Modification on Repeat Chronic Total Occlusion Angioplasty Following an Unsuccessful Attempt

Sub-Intimal Tracking and Re-Entry and Investment Procedures: Current Applications and Future Directions

In seeking to improve upon chronic total occlusion (CTO) percutaneous coronary intervention success rates and minimize risk, CTO modification procedures (investment procedures) have been developed and utilized with increasing frequency. Two key techniques have emerged: subintimal tracking and re-entry (STAR) and subintimal plaque modification (SPM). Both require a staged approach with an index procedure for plaque modification and a second procedure weeks later for stenting. Both approaches require entry and wiring with a polymer-jacketed wire in the extra-plaque space, yet unlike SPM, which exclusively requires angioplasty of the extra-plaque space throughout the CTO segment, STAR also involves re-entry into the true luminal distal to the CTO before angioplasty. STAR and SPM, in many ways, represent a paradigm shift in our approach to CTO percutaneous coronary intervention from a 1-step to a 2-step approach in complex cases. In this review, we discuss the technical aspects of the procedures, and controversies and ongoing trials pointing to the future of these techniques. We also highlight non-device-based and intravascular ultrasound-based approaches to anterograde dissection and re-entry, which add to the CTO operator's toolkit for challenging cases.

Optimal timing of staged percutaneous coronary intervention after subintimal tracking and re-entry: Rationale and design of the subintimal tracking and re-entry with deferred stenting study

BACKGROUND

Ten to fifteen percent of chronic total occlusion (CTO) percutaneous coronary interventions (PCIs) are unsuccessful in contemporary practice. Subintimal tracking and re-entry (STAR) (one form of "investment procedure") with staged reattempt and stenting may further increase the ultimate success and safety of CTO as a bailout strategy. The optimal timing for staged stenting after STAR is unknown.

METHODS AND RESULTS

We designed a six-center, prospective randomized trial with a planned enrollment of 150 patients where STAR is utilized in case of impending failure. The primary aim is to evaluate the optimal timing of the staged PCI after STAR by randomizing the timing to earlier (5-7 weeks) versus later (12-14 weeks) staged PCI. The primary endpoint of the study is the technical success rate of the staged procedure. The secondary endpoints include: (1) the rate of thrombolysis in myocardial infarction 3 flow at the start of staged intervention, (2) rate of partial technical and procedural success of the staged procedure, (3) rate of in-hospital and 12-month major cardiac and cerebrovascular adverse events, and (4) change in patient-reported quality at 30 days, 6 months, and 12 months assessed by Seattle Angina Questionnaire.

CONCLUSION

This study will ascertain the optimal timing of staged stenting after bail-out STAR approach in contemporary CTO PCI (ClinicalTrials.gov NCT05089864).

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.

Practice differences and knowledge gaps in complex and high-risk interventions between Japan and the USA: A case-based discussion

Advances in percutaneous coronary intervention (PCI) devices and techniques have expanded the pool of eligible patients for revascularization, including those with comorbidities, reduced left ventricular function, or anatomical complexity (defined as CHIP: complex and high-risk interventions in indicated patients). CHIP interventions are typically performed by selected operators who specialize in complex PCI. This review presents two cases performed in the USA, to discuss the similarities and differences in practice patterns between CHIP operators in Japan and the USA. The first case involves a 58-year-old male presenting with myocardial infarction and cardiogenic shock, and the second case involves a 51-year-old female with a history of coronary artery bypass grafting presenting with a chronic total occlusion and PCI complicated by vessel perforation. The discussion focuses on appropriate patient selection, the role of the heart team approach for decision-making, the use of hemodynamic support devices, and other relevant factors. By comparing practices in Japan and the USA, this review highlights opportunities for knowledge exchange and potential areas for improving patient outcomes.

Outcomes of Chronic Total Occlusion Percutaneous Coronary Intervention After a Previous Failed Attempt

The impact of a previous failure on 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 9,393 patients who underwent 9,560 CTO PCIs at 42 United States and non-United States centers between 2012 and 2022. A total of 1,904 CTO lesions (20%) had a previous failed PCI attempt. Patients who underwent reattempt CTO PCI were more likely to have a family history of coronary artery disease (37% vs 31%, p <0.001) and dyslipidemia (87.9% vs 84.3%, p <0.001) but were less likely to have heart failure (25.1% vs 29.5%; p <0.001) and cerebrovascular disease (8.7% vs 10.4%, p = 0.04). Patients with previous failure had a higher Japanese CTO (3.33 ± 1.16 vs 2.12 ± 1.19, p <0.001) score and required longer procedure (120 vs 111 minutes, p <0.001) and fluoroscopy (46.9 vs 40.4 minutes, p <0.001) times and higher air kerma radiation dose (2.3 vs 2.1 gray, p = 0.013). Technical success rates (84.3% vs 86.5%, p = 0.011) were lower in patients with a previous failure compared with patients who underwent first-attempt CTO PCI with no significant difference in in-hospital major adverse cardiac events. After adjusting for potential confounders, a previous failure was not associated with technical failure. Operators performing >30 CTO PCIs annually were more likely to achieve technical success in patients with previous failure. In conclusion, a previous failed CTO PCI attempt was associated with higher lesion complexity, longer procedure time, and lower technical success; however, the association with lower technical success did not remain significant in multivariable analysis.

Chronic Total Occlusion Interventions in Patients with Reduced Ejection Fraction

PURPOSE OF THE REVIEW

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.

RECENT FINDINGS

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.

Impact of Subintimal Plaque Modification on Reattempted Chronic Total Occlusions Percutaneous Coronary Intervention

BACKGROUND

Predictors of success in reattempted chronic total occlusion (CTO) percutaneous coronary intervention (PCI) procedures remain obscure, mainly owing to the lack of consecutive angiograms and procedural records of initial attempts in the same cohort.

OBJECTIVES

This study sought to investigate the factors predicting the success of reattempted CTO PCI procedures.

METHODS

A total of 208 consecutive patients who underwent a failed CTO PCI attempt and received reattempted procedure at the same cardiac center were retrospectively analyzed. Predictors of the success of reattempted procedures were evaluated.

RESULTS

The overall technical success rate of reattempted CTO PCI procedures was 71.2%. Subintimal plaque modification (SPM) was implemented in 35 (16.8%) procedures in initial attempts. The reattempted technical success rate was 93.3% in cases in which SPM with guidewire (GW) crossing was achieved in the initial attempt; however, the success rate was 55.0% for procedures involving SPM without GW crossing. SPM with GW crossing (OR: 11.21; 95% CI: 1.31-96.16; P = 0.028), referral to high-volume operators (OR: 2.38; 95% CI: 1.14-4.98; P = 0.021), and a bidirectional approach (OR: 2.31; 95% CI: 1.12-4.79; P = 0.024) were positive independent predictors of technical success in the subsequent reattempt. The time interval for reattempt (per 90-day increment) was negatively correlated with the technical success of the reattempted procedures (OR: 0.85; 95% CI: 0.73-0.98; P = 0.030).

CONCLUSIONS

This study identified independent predictors of success in reattempted CTO PCI procedures. SPM with GW crossing achieved in the initial attempt is associated with a higher success rate in the subsequent reattempt.

Global Chronic Total Occlusion Crossing Algorithm: JACC State-of-the-Art Review

The authors developed a global chronic total occlusion crossing algorithm following 10 steps: 1) dual angiography; 2) careful angiographic review focusing on proximal cap morphology, occlusion segment, distal vessel quality, and collateral circulation; 3) approaching proximal cap ambiguity using intravascular ultrasound, retrograde, and move-the-cap techniques; 4) approaching poor distal vessel quality using the retrograde approach and bifurcation at the distal cap by use of a dual-lumen catheter and intravascular ultrasound; 5) feasibility of retrograde crossing through grafts and septal and epicardial collateral vessels; 6) antegrade wiring strategies; 7) retrograde approach; 8) changing strategy when failing to achieve progress; 9) considering performing an investment procedure if crossing attempts fail; and 10) stopping when reaching high radiation or contrast dose or in case of long procedural time, occurrence of a serious complication, operator and patient fatigue, or lack of expertise or equipment. This algorithm can improve outcomes and expand discussion, research, and collaboration.

Development and validation of a prediction model for angiographic perforation during chronic total occlusion percutaneous coronary intervention: OPEN-CLEAN perforation score

BACKGROUND

Perforation is the most frequent complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) and is associated with adverse events including mortality.

METHODS

Among 1,000 consecutive patients enrolled in 12 center prospective CTO PCI study (OPEN CTO), all perforations were reviewed by the angiographic core-lab. Eighty-nine patients (8.9%) with angiographic perforation were compared to 911 patients without perforation. We sought to describe the clinical and angiographic predictors of angiographic perforation during CTO PCI and develop a risk prediction model.

RESULTS

Among eight clinically important candidate variables, independent risk factors for perforation included prior CABG (OR 2.0 [95% CI, 1.2-3.3], p < .01), occlusion length (OR 1.2 per 10 mm increase [95% CI, 1.1-1.3], p < .01), ejection fraction (OR 1.2 per 10% decrease [95% CI, 1.1-1.5], p < .01), age (OR 1.3 per 5 year increase [95%CI, 1.1-1.5], p < .01), and heavy calcification (OR 1.7 [95% CI, 1.0-2.7], p = .04). Three other potential candidate variables, glomerular filtration rate, proximal cap ambiguity, and target vessel, were not independently associated with perforation. The model was internally validated using bootstrapping methods. From the full model, a simplified perforation prediction score (OPEN-CLEAN score: CABG, Length [occlusion], EF < 50%, Age, CalcificatioN) was developed, which discriminated the risk of angiographic perforation well (c-statistics = 0.75) and demonstrated good calibration.

CONCLUSION

This simple 5-variable prediction score may help CTO operators to risk-stratify patients for angiographic perforation using variables available prior to CTO PCI procedures.

Indications and Patient Selection for Percutaneous Coronary Intervention of Chronic Total Occlusions

The most common indication for chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is angina relief, which translates into improved physical function and quality of life. As the risk of the procedure is higher compared with non CTO PCI, it is important for operators to understand the current state of literature and have a detailed discussion with patients regarding risks and benefits prior to the procedure. This article discusses indications for the procedure and how to appropriately select patients for CTO PCI, in hopes of inspiring the reader to consistently offer this approach to indicated patients regardless of anatomic complexity.

Perforation Mechanisms, Risk Stratification, and Management in the Post-Coronary Artery Bypass Grafting Patient

Coronary perforations during chronic total occlusion percutaneous coronary intervention (CTO PCI) is a most frequent major complication and the incidence is significantly higher compared with non-CTO PCI. Patients with prior history of coronary bypass have more major adverse events when perforation occurs compared with patients without prior bypass surgery. In this article, the authors discuss the unique challenges in identification and timely treatment of perforations in patients with prior bypass surgery.

Intermediate procedural and health status outcomes and the clinical care pathways after chronic total occlusion angioplasty: A report from the OPEN-CTO (outcomes, patient health status, and efficiency in chronic total occlusion hybrid procedures) study

BACKGROUND

No previous reports have described the comprehensive care pathways involved in chronic total occlusion percutaneous coronary intervention (CTO PCI).

METHODS

In a study of 1,000 consecutive patients undergoing CTO PCI using hybrid approach, a systematic algorithm of selecting CTO PCI strategies, the procedural characteristics, complication rates, and patient reported health status outcomes through 12 months were assessed.

RESULTS

Technical success of the index CTO PCI was 86%, with 89% of patients having at least one successful CTO PCI within 12 months. A total of 13.8% underwent CTO PCI of another vessel or reattempt of index CTO PCI within 1 year. At 1 year, the unadjusted major adverse cardiac and cerebral event (MACCE) rate was lower in patients with successful index CTO PCI compared to patients with unsuccessful index CTO PCI (9.4% vs. 14.6%, p = .04). The adjusted hazard ratios of myocardial infarction and death at 12 months were numerically lower in patients with successful index CTO PCI, compared to patients with unsuccessful index CTO PCI. Patients with successful index CTO PCI reported significantly greater improvement in health status throughout 12-months compared to patients with unsuccessful index CTO PCI.

CONCLUSION

CTO-PCI in the real-world often require treatment of second CTO, non-CTO PCI or repeat procedures to treat initially unsuccessful lesions. Successful CTO PCI is associated with numerically lower MACCE at 1 year and persistent symptomatic improvement compared to unsuccessful CTO PCI. Understanding the relationship between the care pathways following CTO PCI and health status benefit requires further study.