The Retrograde Approach to Chronic Total Occlusion Percutaneous Coronary Interventions: Technical Analysis and Procedural Outcomes

Snare-Assisted LAceration of Subintimal Hematoma (SLASH): A Novel Technique for Side Branch Preservation in Bifurcation Chronic Total Occlusion Percutaneous Coronary Intervention

BACKGROUND

Side branch compromise due to extraplaque hematoma often complicates chronic total occlusion (CTO) percutaneous coronary intervention (PCI) involving a bifurcation at the distal cap.

AIMS

To evaluate the feasibility and short-term outcomes of Snare-Assisted LAceration of Subintimal Hematoma (SLASH), a novel technique designed to mitigate this problem.

METHODS

SLASH involves retrograde true lumen wiring across the distal bifurcation into a distal side branch, followed by successful antegrade dissection/re-entry into the same branch. A microsnare is then delivered antegradely and used to capture a retrogradely advanced externalization guidewire. Once snared, controlled traction is applied, inducing a longitudinal laceration of the vessel media and intima, which decompresses the subintimal hematoma at the bifurcation. We conducted a multicenter evaluation to assess the procedural feasibility and outcomes of this technique.

RESULTS

SLASH was performed in 12 complex CTO PCI cases (mean J-CTO score 3.5 ± 0.67). SLASH was successful in 10 (83%) cases, while technical and procedural success was achieved in 9 (75%) cases. In 2 cases, SLASH was unsuccessful due to an inability to deliver the microsnare sheath or failure to snare the retrograde guidewire. No cases of coronary perforation, emergent surgery, or other major procedural complications were observed. In one case, retrograde wire entrapment at a distal graft anastomosis was successfully resolved with rotational atherectomy-induced wire fracture.

CONCLUSION

SLASH is a feasible and effective technique for hematoma decompression and revascularization in bifurcation CTO PCI. Further multicenter studies are warranted to validate its reproducibility, safety, and long-term efficacy.

Chronic Total Occlusion Percutaneous Coronary Intervention: Present and Future

Chronic total occlusion percutaneous coronary intervention has evolved into a subspecialty of interventional cardiology. Using a variety of antegrade and retrograde techniques, experienced operators currently achieve success rates of 85% to 90%, with an incidence of major periprocedural complications of ≈2% to 3%. Several developments in equipment (new microcatheters and guidewires, novel reentry devices), imaging (computed tomography angiography guidance, intravascular imaging for reentry), techniques (intraocclusion contrast injection, advanced subintimal tracking and reentry), and artificial intelligence (automated computed tomography image analysis and prediction of the likelihood of crossing success with various techniques) could further improve outcomes. Global collaboration and rapid dissemination of new developments accelerate the pace of progress. While innovation is exciting and necessary, adhering to the basic principles of chronic total occlusion percutaneous coronary intervention (such as continual assessment of risks and benefits, meticulous angiographic review, and use of dual injection) remains critical for achieving optimal patient outcomes.

Recent Advances in Coronary Chronic Total Occlusions

Coronary chronic total occlusions (CTOs) have been a point of interest of the medical community for the last decade. The natural history of CTOs was for a long time unknown, as the presence of a single CTO was the most frequent cause for the exclusion of patients from randomized controlled trials (RCTs). Recent CTO RCTs have failed to show any benefit in terms of hard endpoints as major adverse cardiovascular events, but have shown a significant improvement in quality of life, as well in the frequency of angina; however, these studies are characterized by the limitation of the short duration of their follow-up period. Real-world data from observational studies indicate a significant improvement in cardiovascular death and overall mortality, suggesting that the results depend on the duration of the follow-up, and not on the procedure per se. The aim of the current review is to summarize all the existing RCTs, and to analyze the most important registries, as well as to present the current development of techniques to boost the successful interventional treatment of CTOs.

Retrograde approach to chronic total occlusion percutaneous coronary interventions- Technique and outcomes

The retrograde approach to chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has significantly contributed to the success rates of CTO PCI. It is usually performed in complex CTO lesions, in which the antegrade approach is not feasible or fails. In this article we discuss the steps to perform retrograde CTO PCI and its complications and success rates. Considering the moderate to high success rates of the retrograde approach in the hands of experienced operators and higher complication rates than antegrade only procedures, optimizing the safety of retrograde CTO PCI is of paramount importance.

Preprocedural Planning for Chronic Total Occlusion Percutaneous Coronary Intervention

Chronic total occlusions (CTO) are frequently encountered in clinical practice. Although the success rates and safety of CTO percutaneous coronary intervention (PCI) have significantly improved with the development of newer equipment, use of an algorithmic approach, and advancement in procedural techniques, CTO PCI has a higher rate of complication than does non-CTO PCI. Therefore, meticulous preprocedural planning before CTO PCI is paramount to improve success and reduce the risk of complications. In this report, we review multiple aspects of preprocedural CTO PCI planning, including procedural indications, efficacy, safety, diagnostic angiography, scoring tools for procedural success and risk prediction, and preprocedural use of computed tomography coronary angiography.

Reclassification of CTO Crossing Strategies in the ERCTO Registry According to the CTO-ARC Consensus Recommendations

BACKGROUND

The CTO-ARC (Chronic Total Occlusion Academic Research Consortium) recognized that a nonstandardized definition of chronic total occlusion (CTO) percutaneous coronary intervention approaches can bias the complications' attribution to each crossing strategy.

OBJECTIVES

The study sought to describe the numbers, efficacy, and safety of each final CTO crossing strategy according to CTO-ARC recommendations.

METHODS

In this cross-sectional study, data were retrieved from the European Registry of Chronic Total Occlusions between 2021 and 2022.

RESULTS

Out of 8,673 patients, antegrade and retrograde approach were performed in 79.2% and 20.8% of cases, respectively. The antegrade approach included antegrade wiring and antegrade dissection and re-entry, both performed with or without retrograde contribution (antegrade wiring without retrograde contribution: n = 5,929 [68.4%]; antegrade wiring with retrograde contribution: n = 446 [5.1%]; antegrade dissection and re-entry without retrograde contribution: n = 353 [4.1%]; antegrade dissection and re-entry with retrograde contribution: n = 137 [1.6%]). The retrograde approach included retrograde wiring (n = 735 [8.4%]) and retrograde dissection and re-entry (n = 1,073 [12.4%]). Alternative antegrade crossing was associated with lower technical success (70% vs 86% vs 93.1%, respectively; P < 0.001) and higher complication rates (4.6% vs 2.9% vs 1%, respectively; P < 0.001) as compared with retrograde and true antegrade crossing. However, alternative antegrade crossing was applied mostly as a rescue strategy (96.1%).

CONCLUSIONS

The application of CTO-ARC definitions allowed the reclassification of 6.7% of procedures as alternative antegrade crossing with retrograde or antegrade contribution which showed higher MACCE and lower technical success rates, as compared with true antegrade and retrograde crossing.

Percutaneous Coronary Intervention for Aorto-Ostial Chronic Total Occlusion: Evaluating Lesion Complexity and Procedural Outcomes

BACKGROUND

PCI for aorto-ostial CTO remains challenging. The techniques for guidewire in aorto-ostial CTO may differ from those used in non-aorto-ostial CTOs, influenced by clinical and angiographic characteristics.

OBJECTIVES

This study aimed to assess the technical aspects and outcomes of percutaneous coronary intervention (PCI) in patients with aorto-ostial chronic total occlusion (CTO).

METHODS

This analysis included 420 patients with ostial CTO from the Japanese CTO-PCI Expert Registry, spanning January 2014 to December 2022. It examined the strategies and procedural outcomes of CTO PCI.

RESULTS

Ostial CTO represented 420 of 10,814 (3.9%) of all CTO PCI cases. Within this subset, aorto-ostial CTO accounted for 218 of 420 (52%) cases. The technical success rate for aorto-ostial CTO was 88% (191/218). Aorto-ostial CTOs exhibited longer lesion lengths and were more likely to present with challenges such as distal target lumen ambiguity, calcification, and tortuosity compared with non-aorto-ostial CTOs. The retrograde approach was more commonly used in aorto-ostial CTO, with retrograde direct crossing being the most successful technique, especially in cases of flush CTO. A multivariate logistic analysis identified several factors significantly associated with unsuccessful aorto-ostial CTO PCI, including difficulties in engaging a guiding catheter, estimating the collateral channel (as assessed by the J-Channel score), and tortuosity.

CONCLUSIONS

Aorto-ostial CTOs are more complex and frequently require a retrograde approach. The availability of suitable interventional collateral channels is crucial for the success of these procedures.

Evaluation of Success and Complications Scores for Chronic Total Occlusion Percutaneous Coronary Interventions: Insights from the Latin American Registry

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.

Dissection and Re-entry Techniques for Chronic Total Occlusion Percutaneous Coronary Intervention

Despite early stagnation in success rates for percutaneous coronary intervention for chronic total occlusion with the traditional antegrade wiring approach, the introduction of dissection/re-entry techniques and the retrograde approach opened new avenues for operators to tackle more complex occlusions. Dissection/re-entry techniques (both antegrade and retrograde) are commonly used in angiographic scenarios characterised by long, tortuous and calcified occlusions, as well as in those with proximal cap ambiguity. Familiarity and comfort using the extraplaque space (with either an antegrade or retrograde approach) have become fundamental to achieving safe and effective recanalisation of complex chronic total occlusions. This review provides an overview of different contemporary antegrade and retrograde dissection re-entry techniques and their acute and longer-term outcomes.

Transradial and Transfemoral Access for Retrograde Chronic Total Occlusion Percutaneous Coronary Interventions: A Comparison of the Clinical Features and Prognostic Implications

Objective

The research was carried out to determine and compare the efficiency of completely transradial access (cTRA) and transfemoral access (TFA) in retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

Background

The cases of retrograde chronic total occlusion (CTO) percutaneous coronary intervention usually need the dual access. The transradial method is now used more frequently in CTO PCI, and improves the safety of CTO PCI.

Methods

This retrospective, observational study was carried out in a single center. Participants were patients who underwent dual-access retrograde CTO PCI from January 2017 to October 2023, categorized into two groups: cTRA (biradial access) and TFA (bifemoral, or combined radial and femoral access). All patients in the cTRA group received conventional radial access. All punctures of the femoral artery were performed without fluoroscopic or ultrasound guidance. None of the patients in the TFA group accepted any arterial closure devices. Clinical, angiographic and procedural characteristics and the occurrence of in-hospital major adverse cardiovascular events (MACE) of the cTRA and TFA procedures were recorded.

Results

This research involved 187 CTO PCI procedures with dual access, of which 88 were done using cTRA and the rest (99) were carried out through TFA. The J-CTO (Multicenter Chronic Total Occlusion Registry of Japan) score was lower in the cTRA group than TFA group (2.1± 0.6 vs 3.0± 0.8; P <0.001). The technical success (84.1% vs 82.8%; P= 0.817), procedural success (80.7% vs 79.8%; P= 0.906) and in-hospital MACE rates (5.7% vs 4.0%; P= 0.510) were the same for both groups. For a J-CTO score of 3 or higher, technical success rate was significantly lower in the cTRA group than the TFA group (58.1% vs 74.2%; P < 0.001).

Conclusion

In the retrograde CTO PCI, the percentages of success and in-hospital MACE were similar for both cTRA and TFA. Meanwhile, cTRA may be used for simpler lesions (J-CTO score < 3) as compared to TFA.

Impact of successful antegrade and retrograde CTO PCI on short-term prognosis

BACKGROUND

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) carries risk of complications and should be attempted when the anticipated benefits exceed the potential risks. The primary indication for CTO-PCI is symptom improvement. However, the impact of CTO-PCI on angina and subsequent incidence of major adverse cardiovascular event (MACE) rate remains controversial. Our aim was to study the impact of technically successful elective CTO-PCI on the procedural success rate and short-term MACE. The current study was a prospective cohort study that included a total of 80 patients who were referred to our center (Ain Shams University Hospitals) for elective CTO-PCI and underwent technically successful CTO-PCI. Data were collected on patient arrival to our department, and then, the patients were observed during hospital admission to record any In-Hospital MACE. These patients were then followed up for 6 months to record improvement or worsening of their symptoms and to assess occurrence of any MACE including hospitalization and undergoing symptom-driven coronary angiography.

RESULTS

The mean age of our patients was 56 ± 9.6 years, and 73 patients (91%) were men. Sixty-two patients (77.5%) were done via an antegrade approach, and 18 patients (22.5%) were done via a retrograde approach with an overall procedural success rate of 91.25% (antegrade 93.5%, retrograde 83.3%). The overall mean procedure time was 102 min, the mean contrast volume used was 371 ml, and the mean cumulative air kerma dose was 7.2 Gy. The retrograde group required longer procedure times, larger volumes of contrast and higher exposure to radiation. The overall in-hospital MACE was 8.75%. Sixty-five patients in our study (81.25%) showed an improvement in the grade of their exertional dyspnea or angina within the 6-month follow-up period. Thirteen patients in our study (16.25%) needed re-hospitalization within a 6-month period after PCI. The overall target lesion revascularization rate at 6 months was 8.75%.

CONCLUSIONS

Technically successful CTO PCI in a well-equipped center with highly qualified CTO operators resulted in high procedural success rates and low incidence of short-term MACE.

Controlled antegrade and retrograde subintimal tracking (CART) for recanalisation of chronic total occlusions

BACKGROUND

Controlled antegrade and retrograde subintimal tracking (CART) is rarely performed in contemporary chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

AIMS

We aimed to analyse the indications, procedural characteristics, and outcomes of CART at a high-volume CTO programme.

METHODS

We included all patients undergoing a retrograde CTO PCI in which CART was performed at our institution between January 2019 and November 2023. The primary endpoint was technical success.

RESULTS

Of 1,582 CTO PCI, the retrograde approach was performed in 603 procedures (38.1%), and CART was used in 45 cases (7.5%). The mean age was 69.1±10.3 years, 93.3% were male, and prior coronary artery bypass graft surgery was present in 68.9%. The most common target CTO vessel was the right coronary artery (48.9%). Anatomical complexity was high (Multicentre CTO Registry of Japan [J-CTO] score of 3.6±0.9). The most common collateral used for CART was a saphenous vein graft (62.2%). Advanced calcium modification was required in 15.6% of cases. CART was successful in 73.3%. Technical and procedural success was 82.2%. Coronary perforation was diagnosed in 4 subjects (8.9%), but only 1 patient (2.2%) suffered tamponade and required pericardiocentesis. No other in-hospital major adverse cardiac events were diagnosed.

CONCLUSIONS

CART is a useful technique in selected, very complex CTOs tackled with the retrograde approach. Success rates were high, while complication rates were low, considering the high anatomical complexity and baseline patient risk.