Chronic Total Occlusion Percutaneous Coronary Intervention: Mindset, Culture, and Continuous Improvement.

The development of complex and higher-risk indicated procedures (CHIP) and chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has brought new challenges in terms of operator training. Although the technical aspects of learning CHIP/CTO PCI have been described in detail, very little has been discussed concerning the mental skills that the operator must possess or develop to be successful. Moreover, an at least equally important aspect of CHIP/CTO PCI program development is the professional culture of the institution where these complex procedures are performed, because this can mark the difference between a thriving and long-lasting program and one that is quickly bound to fail. This article analyzes the mental attributes of the CHIP/CTO PCI operator and outlines several leadership principles that can be applied to foster a growth culture and develop a thriving program.

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.

Comparative Analysis of Polymer Versus Non-Polymer Jacketed Wires in Chronic Total Occlusion Percutaneous Coronary Intervention.

There is significant variation in wire utilization patterns for chronic total occlusion (CTO) percutaneous coronary intervention. This study aimed to compare the outcomes of polymer-jacketed wires (PJWs) versus non-PJWs in anterograde procedures. We analyzed clinical and angiographic characteristics, and procedural outcomes of 7,575 anterograde CTO percutaneous coronary interventions that were performed at 47 centers between 2012 and 2023. Cases in which PJWs were exclusively used were classified in the PJW group, whereas cases where at least one non-PJW was employed were classified in the non-PJW group. Study end points were as follows: technical success, coronary perforation, major adverse cardiac event. PJWs were exclusively used in 3,481 cases (46.0%). These cases had lower prevalence of proximal cap ambiguity, blunt stump, and moderate/severe calcification. They also had lower Japanese CTO (J-CTO), Prospective Global Registry for the Study of Chronic Total Occlusion (PROGRESS-CTO), and PROGRESS-CTO complications scores, higher technical success (94.3% vs 85.7%, p <0.001), and lower perforation rates (2.2% vs 3.2%, p = 0.013). Major adverse cardiac event rates did not differ between groups (1.3% vs 1.5%, p = 0.53). Exclusive use of PJWs was independently associated with higher technical success in both the multivariable (odds ratio [OR] 2.66, 95% confidence interval [CI] 2.13 to 3.36, p <0.001) and inverse probability of treatment weight analysis (OR 2.43, 95% CI 2.04 to 2.89, p <0.001). Exclusive use of PJWs was associated with lower risk of perforation in the multivariable analysis (OR 0.69, 95% CI 0.49 to 0.95, p = 0.02), and showed a similar trend in the inverse probability of treatment weight analysis (OR 0.77, 95% CI 0.57 to 1.04, p = 0.09). Exclusive use of PJWs is associated with higher technical success and lower perforation risk in this non-randomized series of patients.

Intracoronary snaring of the retrograde guidewire: A novel method to solve compartment mismatch in complex retrograde CTO PCI.

The retrograde approach has allowed a remarkable improvement in the success rate of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). After collateral channel crossing, the most crucial aspect of retrograde CTO PCI is creating the connection between the antegrade and retrograde system. Currently, the most common technique to achieve this is reverse controlled antegrade and retrograde subintimal tracking. However, this maneuver sometimes fails due to compartment mismatch (intraplaque situation of one wire and extraplaque situation of the other). New approaches are therefore needed to overcome challenges in this important step of the procedure. Here we present an innovative solution to this problem, which involved capturing the retrograde guidewire (advanced into a side branch at the distal cap) with a microsnare that had been advanced antegradely: this severed the dissection flap separating the antegrade and retrograde system, thus allowing us to successfully recanalize the CTO.

Extreme coronary radiation doses from intravascular brachytherapy.

PURPOSE: To evaluate coronary artery integrity after very high radiation doses from intravascular brachytherapy (IVBT) in the setting of source asymmetry. METHODS: Ten patients treated for right coronary artery (RCA) in-stent restenosis (ISR) between 2017 and 2021 and for whom follow-up angiograms were available were identified from departmental records. Procedural angiograms, taken to document source position, were used to estimate vascular wall doses. The 2.5 mm proximal source marker was used to estimate the distance from source center to the media and adventitia. Distances were converted to dose (Gy) using the manufacturers' dose fall-off table, measured in water. Follow-up films were scrutinized for any sign of late vascular damage. RESULTS: The average minimal distance from catheter center to the adjacent media and the adventitia was 0.9 mm (±0.2) mm and 1.4 mm (±0.2), respectively. The average maximum media and adventitial doses adjacent to the source were 75 Gy (±26) and 39 Gy (±14), respectively. Follow-up angiograms were available from 0.6 years to 3.9 years following IVBT (median: 1.6 years). No IVBT-treated vascular segment showed signs of degeneration, dissection or aneurysm. CONCLUSION: IVBT vascular wall doses are frequently far higher than prescribed. The lack of complications in this unselected group of patients gives a modicum of reassurance that raising the prescription dose is unlikely to lead to a sudden appearance of complications.

International survey of chronic total occlusion percutaneous coronary intervention operators.

BACKGROUND: Contemporary chronic total occlusion (CTO) percutaneous coronary intervention (PCI) practice has received limited study. AIM: To examine the contemporary CTO PCI practice. METHODS: We performed an online, anonymous, international survey of CTO PCI operators. RESULTS: Five hundred forty-five CTO PCI operators and 190 interventional cardiology fellows with an interest in CTO PCI participated in this survey. Almost half were from the United States (41%), most (93%) were men, and the median h/week spent in the hospital was 58. Median annual case numbers were 205 (150-328) for PCIs and 20 (5-50) for CTO PCIs. Almost one-fifth (17%) entered CTO cases into registries, such as PROGRESS-CTO (55%) and EuroCTO (20%). More than one-third worked at academic institutions (39%), 31% trained dedicated CTO fellows, and 22% proctored CTO PCI. One-third (34%) had dedicated CTO PCI days. Most (51%) never discharged CTO patients the same day, while 17% discharged CTO patients the same day >50% of the time. After successful guidewire crossing, 38% used intravascular imaging >90% of the time. Most used CTO scores including J-CTO (81%), PROGRESS-CTO (35%), and PROGRESS-CTO complications scores (30%). Coronary artery perforation was encountered within the last month by 19%. On a scale of 0-10, the median comfort levels in treating coronary artery perforation were: covered stents 8.8 (7.0-10), coil embolization 5.0 (2.1-8.5), and fat embolization 3.7 (0.6-7.3). Most (51%) participants had a complication cart/kit and 25% conducted regular complication drills with catheterization laboratory staff. CONCLUSION: Contemporary CTO PCI practices vary widely. Further research on barriers to following the guiding principles of CTO PCI may improve patient outcomes.

Increased prescription dose for large vessel intravascular brachytherapy.

BACKGROUND: Most randomized studies testing the effectiveness of IVBT were limited to vessels less than 4 mm diameter. In fact, it is now common to treat vessels larger than 4 mm. Accordingly, the authors instituted a prescription dose increase to 34 Gy at 2 mm from source center for vessels greater than 4.0 mm. The increase in prescription dose to 34 Gy at 2 mm from center is substantial, being 50% higher than the conventional maximum of 23 Gy. AIM: To take a close look at group of patients treated to 34 Gy, and for whom follow-up angiograms are available. METHODS: Ten patients treated for ISR with a prescription dose of 34 Gy and for whom follow-up angiograms were available were studied. Beta-radiation brachytherapy was performed with a Novoste Beta-Cath System using a strontium-90 (beta) source (Best Vascular, Springfield, VA). Source lengths of 40 or 60 mm were used. A dose of 34 Gy was prescribed at 2 mm from the source center. RESULTS: Patients were re-catheterized from 2 to 21 months (median: 16 months) following IVBT, all for symptoms suggested of restenosis. All patients had some degree of ISR of the target vessel, but no IVBT-treated vascular segment showed angiographic signs of degeneration, dissection or aneurysm. CONCLUSION: The authors' clinical impression, along with detailed review of the 10 cases, suggest that using a 34 Gy prescription dose at 2 mm from source center does not result in increased toxicity.

PCI for Flush Occluded Right Coronary Artery: Challenges and Techniques for Success.

A 74-year-old man with prior coronary artery bypass surgery had a failing vein graft to the right coronary artery (RCA). He underwent retrograde chronic total occlusion recanalization of an ostial flush-occluded RCA facilitated by retrograde angioplasty at the aorto-ostial junction after failed retrograde electrocautery. The graft was then sacrificed. (Level of Difficulty: Advanced.).

Electrocautery-assisted re-entry to resolve bilateral aorto-ostial chronic total occlusions due to leaflet obstruction following transcatheter aortic valve replacement.

Coronary artery obstruction is a rare but life-threatening complication of transcatheter aortic valve replacement (TAVR). While urgent percutaneous coronary intervention has been described in cases of acute occlusion, little is known about the interventional management of obstruction once it has occurred in the chronic setting. We describe a case in which electrocautery-assisted re-entry was successfully utilized to manage the right coronary artery and left main chronic total occlusion due to leaflet-induced coronary artery obstruction after TAVR.

The contemporary role of protamine in the cardiac catheterization laboratory.

Access to the arterial circulation and full anticoagulation carries a risk of serious bleeding during and after percutaneous coronary intervention. Important sources of bleeding include the arterial access site and coronary artery perforation. Prompt and effective management of hemorrhagic complications is an essential interventional skill. Protamine sulfate is well-known as a heparin reversal agent. Despite this, there is heterogeneity in the use of protamine during interventional procedures. While protamine is generally well-tolerated, it is associated with a risk of hypersensitivity reaction, including anaphylaxis, among others. The purpose of this review is to summarize the existing evidence about and experience with the use of protamine sulfate in the setting of percutaneous coronary and structural interventional procedures.

Complex Retrograde Chronic Occlusion Percutaneous Coronary Intervention via a Gastroepiploic Artery Graft.

Surgical bypass grafts are commonly used retrograde conduits to facilitate chronic total occlusion (CTO) percutaneous coronary intervention (PCI). While extensive experience exists using saphenous vein grafts as retrograde conduits in CTO PCI, information on the utilization of arterial grafts is more limited. In particular, the gastroepiploic artery (GEA) is a very uncommonly used arterial graft in contemporary bypass surgery and its role for retrograde CTO recanalization has received little study. We describe a case of right coronary artery CTO that was recanalized using the retrograde approach via a GEA graft to the posterior descending artery and highlight the specific challenges of this approach.

Image-guided intravascular brachytherapy dose escalation.

PURPOSE: Coronary stents reduce IVBT radiation dose with a single layer by 10-30%. However, the impact of multiple stent layers and stent expansion remains unexplored. Individualized dose adjustments considering variations in stent layers and expansion could improve radiation delivery effectiveness. METHODS: EGSnrc was used to compute the delivered vessel wall dose in various IVBT scenarios. Stent effects were modeled for the stent density of 25%, 50%, and 75% with 1, 2, and 3 layers respectively. Doses were calculated at 1.75 to 5.00 mm away from the source center, normalized to 100% at 2 mm. RESULTS: Dose fall-off increased with increasing stent density. With a single layer, the dose at 2 mm from source fell from 100% of prescription to 92%, 83% and 73% at 25%, 50% and 75% density, respectively. The computed dose to points with increasing radial distance from the source decreased progressively with increasing stent layers. With three layers, at 75% stent density, the dose at 2 mm from source center fell to 38%. CONCLUSIONS: A schema for image-guided IVBT dose adjustment is described. While it would be an improvement over current standard of care, myriad factors remain to be addressed in a comprehensive effort to optimize IVBT.

Outcomes of Medical Therapy Plus PCI for Multivessel or Left Main CAD Ineligible for Surgery.

BACKGROUND: Percutaneous coronary intervention (PCI) is increasingly used to revascularize patients ineligible for CABG, but few studies describe these patients and their outcomes. OBJECTIVES: This study sought to describe characteristics, utility of risk prediction, and outcomes of patients with left main or multivessel coronary artery disease ineligible for coronary bypass grafting (CABG). METHODS: Patients with complex coronary artery disease ineligible for CABG were enrolled in a prospective registry of medical therapy + PCI. Angiograms were evaluated by an independent core laboratory. Observed-to-expected 30-day mortality ratios were calculated using The Society for Thoracic Surgeons (STS) and EuroSCORE (European System for Cardiac Operative Risk Evaluation) II scores, surgeon-estimated 30-day mortality, and the National Cardiovascular Data Registry (NCDR) CathPCI model. Health status was assessed at baseline, 1 month, and 6 months. RESULTS: A total of 726 patients were enrolled from 22 programs. The mean SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) score was 32.4 ± 12.2 before and 15.0 ± 11.7 after PCI. All-cause mortality was 5.6% at 30 days and 12.3% at 6 months. Observed-to-expected mortality ratios were 1.06 (95% CI: 0.71-1.36) with The Society for Thoracic Surgeons score, 0.99 (95% CI: 0.71-1.27) with the EuroSCORE II, 0.59 (95% CI: 0.42-0.77) using cardiac surgeons' estimates, and 4.46 (95% CI: 2.35-7.99) using the NCDR CathPCI score. Health status improved significantly from baseline to 6 months: SAQ summary score (65.9 ± 22.5 vs 86.5 ± 15.1; P < 0.0001), Kansas City Cardiomyopathy Questionnaire summary score (54.1 ± 27.2 vs 82.6 ± 19.7; P < 0.0001). CONCLUSIONS: Patients ineligible for CABG who undergo PCI have complex clinical profiles and high disease burden. Following PCI, short-term mortality is considerably lower than surgeons' estimates, similar to surgical risk model predictions but is over 4-fold higher than estimated by the NCDR CathPCI model. Patients' health status improved significantly through 6 months.

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.

Validation of the new PROGRESS-CTO complication risk scores in the OPEN-CTO registry.

BACKGROUND: Risk stratification before chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is important to inform procedural planning as well as patients and their families. We sought to externally validate the PROGRESS-CTO complication risk scores in the OPEN-CTO registry. METHODS: OPEN-CTO is a prospective registry of 1000 consecutive CTO PCIs performed at 12 experienced US centers using the hybrid algorithm. Endpoints of interest were in-hospital all-cause mortality, need for pericardiocentesis, acute myocardial infarction (MI), and major adverse cardiovascular events (MACE) (a composite of all-cause mortality, stroke, periprocedural MI, urgent repeat revascularization, and tamponade requiring pericardiocentesis). Model discrimination was assessed with the area under the curve (AUC) method, and calibration with the observed-versus-predicted probability method. RESULTS: Mean age was 65.4 ± 10.3 year, and 36.5% of patients had prior coronary artery bypass graft. Overall, 41 patients (4.1%) suffered MACE, 9 (0.9%) mortality, 26 (2.6%) acute MI, and 11 (1.1%) required pericardiocentesis. Technical success was achieved in 86.3%. Patients who experienced MACE had higher anatomic complexity, and more often required antegrade dissection/reentry and the retrograde approach. Increasing PROGRESS-CTO MACE scores were associated with increasing MACE rates: 0.5% (score 0-1), 2.4% (score 2), 3.7% (score 3), 4.5% (score 4), 7.8% (score 5), 13.0% (score 6-7). The AUC were as follows: MACE 0.72 (95% confidence interval [CI]: 0.66-0.78), mortality 0.79 (95% CI: 0.66-0.95), pericardiocentesis 0.71 (95% CI: 0.60-0.82), and acute MI 0.57 (95% CI: 0.49-0.66). Calibration was adequate for MACE and mortality, while the models underestimated the risk of pericardiocentesis and acute MI. CONCLUSIONS: In a large external cohort of patients treated with the hybrid algorithm by experienced CTO operators, the PROGRESS-CTO MACE, mortality, and pericardiocentesis risk scores showed good discrimination, while the acute MI score had inferior performance.

Stingray CART (K14 technique): A novel antegrade dissection reentry strategy.

A novel device based CART technique (K14 technique) has been described with 2 case examples to illustrate the same. This CART has been performed after ADR and Reverse-CART were unsuccessful.

External validation of the PROGRESS-CTO perforation risk score: Individual patient data pooled analysis of three registries.

BACKGROUND: Coronary artery perforation is one of the most feared and common complications of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: To assess the usefulness of the recently developed PROGRESS-CTO (NCT02061436) perforation risk score in independent cohorts. Individual patient-level data pooled analysis of three registries was performed. RESULTS: Of the 4566 patients who underwent CTO PCI at 25 centers, 196 (4.2%) had coronary artery perforation. Patients with perforations were older (69 ± 10 vs. 65 ± 10, p < 0.001), more likely to be women (19% vs. 13%, p = 0.009), more likely to have a history of prior coronary artery bypass graft (34% vs. 20%, p < 0.001), and unfavorable angiographic characteristics such as blunt stump (62% vs. 48%, p < 0.001), proximal cap ambiguity (52% vs. 34%, p < 0.001), and moderate-severe calcification (60% vs. 49%, p = 0.002). Technical success was lower in patients with perforations (73% vs. 88%, p < 0.001). The area under the receiver operating characteristic curve of the PROGRESS-CTO perforation risk model was 0.76 (95% confidence interval [CI], 0.72-0.79), with good calibration (Hosmer-Lemeshow p = 0.97). We found that the CTO PCI perforation risk increased with higher PROGRESS-CTO perforation scores: 0.3% (score 0), 2.3% (score 1), 3.1% (score 2), 5.5% (score 3), 7.5% (score 4), 14.6% (score 5). CONCLUSION: Given the good discriminative performance, calibration, and the ease of calculation, the PROGRESS-CTO perforation score may facilitate assessment of the risk of perforation in patients undergoing CTO PCI.