Sub-intimal tracking and re-entry and investment procedures: current applications and future directions.

In seeking to improve upon CTO percutaneous coronary intervention (PCI) 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 (EPS), yet unlike SPM which exclusively requires angioplasty of the EPS throughout the CTO segment, STAR also involves re-entry into the true lumen distal to the CTO before angioplasty. STAR and SPM in many ways represent a paradigm shift in our approach to CTO PCI from a 1-step to 2-step approach in complex cases. In this review, we discuss the technical aspects of the procedures, as well as controversies and ongoing trials pointing to the future of these techniques. We also highlight non-device-based and intravascular ultrasound-based approaches to antegrade dissection and re-entry, which add to the CTO operator's toolkit for challenging cases.

Peripheral artery disease in chronic total occlusion percutaneous coronary intervention.

Background: The impact of peripheral artery disease (PAD) on the outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is not well studied. Methods: We analyzed the association of PAD with CTO-PCI outcomes using data from the PROGRESS-CTO registry of procedures performed at 47 centers between 2012 and 2023. Results: The prevalence of PAD among 12 961 patients who underwent CTO PCI during the study period was 13.9% (1802). PAD patients were older, more likely to be current smokers, and had higher rates of dyslipidemia, diabetes, cerebrovascular disease, hypertension, prior myocardial infarction, PCI, and coronary artery bypass graft surgery. Their PROGRESS-CTO (1.35 vs 1.22; P < .001) and J-CTO (2.63 vs 2.33; P < .001) scores were higher, lesion length was longer, and angiographic characteristics were more complex. Their access site was more likely to be bifemoral (33.6% vs 30.9%; P = .024) compared with patients with no PAD. Technical (82.9% vs 87.7%; P < .001) and procedural (80.5% vs 86.6%; P < .001) success rates were lower in patients with PAD, while the incidence of major adverse cardiovascular events (MACE) was higher (3.1% vs 1.8%; P < .001), with higher mortality (0.8% vs 0.4%; P = .034), acute myocardial infarction rate (0.9% vs 0.4%; P = .010), and perforations rate (6.6% vs 4.5%; P < .001). In multivariable analysis, PAD was associated with higher MACE (odds ratio [OR]: 1.53; 95% CI, 1.01-2.26; P = .038) and lower technical success (OR: 0.82; 95% CI, 0.69-0.99; P = .039). Conclusions: PAD patients undergoing CTO PCI have higher comorbidity burden, more complex CTOs, higher MACE, and lower technical success.

Use of dual-lumen microcatheter pullback injection in complex percutaneous coronary intervention.

Dual-lumen microcatheters (DLMC) are utilized in challenging wiring scenarios as well as for contrast and medication injections. Nonetheless, lesion characterization remains extremely challenging in many cases. We describe a DLMC-facilitated technique which can assist in locating the distal anastomosis while navigating an occluded bypass graft during retrograde chronic total occlusion recanalization, as well as in the differential diagnosis of abrupt vessel closure. This "DLMC Pullback Injection" technique is performed by injecting contrast through the over-the-wire port of the DLMC, while the latter is quickly pulled back across the region of interest in a dynamic fashion. We believe this technique has the potential to solve challenging scenarios and to enrich the complex percutaneous coronary intervention operator's armamentarium.

Left atrial compression syndrome secondary to coronary artery perforation: Pathophysiology, diagnosis, and management strategies.

Coronary perforation (CP) poses a significant risk of morbidity and mortality, particularly, in patients with a history of cardiac surgery. The occurrence of loculated pericardial effusion presents distinctive challenges in these postcardiac surgical patients. This study delves into the complexities arising from the formation of loculated pericardial effusions subsequent to CP, with a specific focus on the loculated effusion in the posterior wall leading to left atrial compression syndrome. This analysis is dedicated to elucidating pathophysiology diagnostic and treatment strategies tailored for addressing left atrium compression syndrome, providing invaluable insights into the intricacies of diagnosing, treating, and managing this entity in the postcardiac surgical patient.

Percutaneous coronary interventions for aneurysmatic right coronary artery in acute coronary syndrome: RIGHTMARE registry outcomes.

BACKGROUND: The optimal strategy during percutaneous coronary intervention (PCI) of aneurysmatic right coronary artery (ARCA) remains uncertain and has never been tested in the acute setting. OBJECTIVES: To compare the in-hospital and long-term outcomes of immediate and staged PCI strategies for ARCA as culprit lesions during acute coronary syndrome (ACS). METHODS: Among 102.376 PCIs performed in 18 European centers, a total of 85 patients presenting with acute coronary syndrome undergoing ARCA PCI were finally included in the analysis. PCI strategy (stenting performed during the immediate vs staged procedure) and pharmacological approach adopted were collected. The primary outcome was procedural success (technical success without in-hospital MACE). RESULTS: The primary outcome occurred in 48.2 % of cases, with no significant differences observed between the immediate and staged PCI groups (50.9 % vs 43.3 %, p = 0.504). Patients in the staged-PCI group had a significantly higher rate of intravenous anticoagulant use (83.3 % vs 48.1 %, p = 0.002), BARC type 3 and 5 bleedings (12.9 % vs 1.9 %, p = 0.037), and longer in-hospital stay (7.40 ± 5.11 vs 9.5 ± 5.25 days, p = 0.049). After multivariate analysis, no independent predictors for procedural success were found in either group. Target lesion failure occurred in 24.1 % of cases without differences between groups at a median follow-up of three years. CONCLUSIONS: Among patients undergoing ARCA PCI in the setting of ACS, immediate or staged PCI were associated with similar in-hospital and long-term outcomes. However, staged PCI was associated with a higher risk of major bleeding events and longer length of stay compared to immediate PCI strategy.

Contemporary Trends and Outcomes of Intravascular Lithotripsy in Percutaneous Coronary Intervention: Insights From BMC2.

BACKGROUND: With an aging population and an increase in the comorbidity burden of patients undergoing percutaneous coronary intervention (PCI), the management of coronary calcification for optimal PCI is critical in contemporary practice. OBJECTIVES: This study sought to examine the trends and outcomes of coronary intravascular lithotripsy (IVL), rotational/orbital atherectomy, or both among patients who underwent PCI in Michigan. METHODS: We included all PCIs between January 1, 2021, and June 30, 2022, performed at 48 Michigan hospitals. Outcomes included in-hospital major adverse cardiac events (MACEs) and procedural success. RESULTS: IVL was used in 1,090 patients (2.57%), atherectomy was used in 1,743 (4.10%) patients, and both were used in 240 patients (0.57% of all PCIs). IVL use increased from 0.04% of PCI cases in January 2021 to 4.28% of cases in June 2022, ultimately exceeding the rate of atherectomy use. The rate of MACEs (4.3% vs 5.4%; P = 0.23) and procedural success (89.4% vs 89.1%; P = 0.88) were similar among patients treated with IVL compared with atherectomy, respectively. Only 15.6% of patients treated with IVL in contemporary practice were similar to the population enrolled in the pivotal IVL trials. Among such patients (n = 169), the rate of MACEs (0.0%) and procedural success (94.7%) were similar to the outcomes reported in the pivotal IVL trials. CONCLUSIONS: Since its introduction in February 2021, coronary IVL use has steadily increased, exceeding atherectomy use in Michigan by February 2022. Contemporary use of IVL and atherectomy is generally associated with high rates of procedural success and low rates of complications.

Predicting Successful Chronic Total Occlusion Crossing With Primary Antegrade Wiring Using Machine Learning.

BACKGROUND: There is limited data on predicting successful chronic total occlusion crossing using primary antegrade wiring (AW). OBJECTIVES: The aim of this study was to develop and validate a machine learning (ML) prognostic model for successful chronic total occlusion crossing using primary AW. METHODS: We used data from 12,136 primary AW cases performed between 2012 and 2023 at 48 centers in the PROGRESS CTO registry (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention; NCT02061436) to develop 5 ML models. Hyperparameter tuning was performed for the model with the best performance, and the SHAP (SHapley Additive exPlanations) explainer was implemented to estimate feature importance. RESULTS: Primary AW was successful in 6,965 cases (57.4%). Extreme gradient boosting was the best performing ML model with an average area under the receiver-operating characteristic curve of 0.775 (± 0.010). After hyperparameter tuning, the average area under the receiver-operating characteristic curve of the extreme gradient boosting model was 0.782 in the training set and 0.780 in the testing set. Among the factors examined, occlusion length had the most significant impact on predicting successful primary AW crossing followed by blunt/no stump, presence of interventional collaterals, vessel diameter, and proximal cap ambiguity. In contrast, aorto-ostial lesion location had the least impact on the outcome. A web-based application for predicting successful primary AW wiring crossing is available online (PROGRESS-CTO website) (https://www.progresscto.org/predict-aw-success). CONCLUSIONS: We developed an ML model with 14 features and high predictive capacity for successful primary AW in chronic total occlusion percutaneous coronary intervention.

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.

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).

Geographic diversity in chronic total occlusion percutaneous coronary intervention: insights from the PROGRESS-CTO registry.

BACKGROUND: There is variability in clinical and lesion characteristics as well as techniques in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We analyzed patient and lesion characteristics, techniques, and outcomes in 11 503 CTO-PCI procedures performed in North America (NA) and in the combined regions of Europe, Asia, and Africa from 2017 to 2023 as documented in the PROGRESS-CTO registry. RESULTS: Eight thousand four hundred seventy-nine (74%) procedures were performed in NA. Compared with non-NA patients, NA patients were older, with higher body mass index and higher prevalence of diabetes, hypertension, dyslipidemia, family history of coronary artery disease, prior history of PCI, coronary artery bypass graft surgery and heart failure, cerebrovascular disease, and peripheral arterial disease. Their CTOs were more complex, with higher J-CTO (2.56 ± 1.22 vs 1.81 ± 1.24; P less than .001) and PROGRESS-CTO (1.29 ± 1.01 vs 1.07 ± 0.95; P less than .001) scores, longer length, and higher prevalence of proximal cap ambiguity, blunt/no stump, moderate to severe calcification, and proximal tortuosity. Retrograde (31.0% vs 22.1%; P less than .001) and antegrade dissection and re-entry (ADR) (21.2% vs 9.2%; P less than .001) were more commonly used in NA centers, along with intravascular ultrasound (69.0% vs 10.1%; P less than .001). Procedure and fluoroscopy times were longer in NA, while contrast volume and radiation dose were lower. Technical (86.7% vs 86.8%; P > .90) and procedural (85.4% vs 85.8%; P = .70) success and in-hospital major adverse cardiovascular events (MACE) (1.9% vs 1.7%; P = .40) were similar in NA and non-NA centers. CONCLUSIONS: Compared with non-NA patients, NA patients undergoing CTO PCI have more comorbidities, higher CTO lesion complexity, are more likely to undergo treatment with retrograde and ADR, and have similar technical success and MACE.

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.

Ranolazine in chronic total occlusion percutaneous coronary intervention.

Ranolazine is an anti-anginal medication given to patients with chronic angina and persistent symptoms despite medical therapy. We examined 11 491 chronic total occlusion (CTO) percutaneous coronary interventions (PCI) that were performed at 41 US and non-US centers between 2012 and 2023 in the PROGRESS-CTO Registry. Patients on ranolazine at baseline had more comorbidities, more complex lesions, lower procedural and technical success (based on univariable but not multivariable analysis), and higher incidence of major adverse cardiac events (MACE) (on both univariable and multivariable analysis).

Validation of the BCIS CHIP Score in chronic total occlusion percutaneous coronary intervention.

BACKGROUND: The complex high-risk indicated percutaneous coronary intervention (CHIP) score is a tool developed using the British Cardiovascular Intervention Society (BCIS) database to define CHIP cases and predict in-hospital major adverse cardiac or cerebrovascular events (MACCE). AIM: To assess the validity of the CHIP score in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We evaluated the performance of the CHIP score on 8341 CTO PCIs from the Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS-CTO) performed at 44 centers between 2012 and 2023. RESULTS: In our cohort, 7.8% (n = 647) of patients had a CHIP score of 0, 50.2% (n = 4192) had a CHIP score of 1-2, 26.2% (n = 2187) had a CHIP score of 3-4, 11.7% (n = 972) had a CHIP score of 5-6, 3.3% (n = 276) had a CHIP score of 7-8, and 0.8% (n = 67) had a CHIP score of 9+. The incidence of MACCE for a CHIP score of 0 was 0.6%, reaching as high as 8.7% for a CHIP score of 9+, confirming that a higher CHIP score is associated with a higher risk of MACCE. The estimated increase in the risk of MACCE per one score unit increase was 100% (95% confidence interval [CI]: 65%-141%). The AUC of the CHIP score model for predicting MACCE in our cohort was 0.63 (95% CI: 0.58-0.67). There was a positive correlation between the CHIP score and the PROGRESS-CTO MACE score (Spearman's correlation: 0.37; 95% CI: 0.35-0.39; p < 0.001). CONCLUSIONS: The CHIP score has modest predictive capacity for MACCE in CTO PCI.

Retrograde chronic total occlusion percutaneous coronary intervention via ipsilateral collaterals.

BACKGROUND: There is limited data on retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI) via ipsilateral epicardial collaterals (IEC). AIMS: To compare the clinical and angiographic characteristics, and outcomes of retrograde CTO PCI via IEC versus other collaterals in a large multicenter registry. METHODS: Observational cohort study from the Prospective Global registry for the study of Chronic Total Occlusion Intervention (PROGRESS-CTO). RESULTS: Of 4466 retrograde cases performed between 2012 and 2023, crossing through IEC was attempted in 191 (4.3%) cases with 50% wiring success. The most common target vessel in the IEC group was the left circumflex (50%), in comparison to other retrograde cases, where the right coronary artery was most common (70%). The Japanese CTO score was similar between the two groups (3.13 ± 1.23 vs. 3.06 ± 1.06, p = 0.456); however, the IEC group had a higher Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS-CTO) score (1.95 ± 1.02 vs. 1.27 ± 0.92, p < 0.0001). The most used IEC guidewire was the SUOH 03 (39%), and the most frequently used microcatheter was the Caravel (43%). Dual injection was less common in IEC cases (66% vs. 89%, p < 0.0001). Technical (76% vs. 79%, p = 0.317) and procedural success rates (74% vs. 79%, p = 0.281) were not different between the two groups. However, IEC cases had a higher procedural complications rate (25.8% vs. 16.4%, p = 0.0008), including perforations (17.3% vs. 9.0%, p = 0.0001), pericardiocentesis (3.1% vs. 1.2%, p = 0.018), and dissection/thrombus of the donor vessel (3.7% vs. 1.2%, p = 0.002). CONCLUSION: The use of IEC for retrograde CTO PCI was associated with similar technical and procedural success rates when compared with other retrograde cases, but higher incidence of periprocedural complications.