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.

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.

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).

Impact of age over 70 years in the new allocation system on the outcomes of heart transplantation in the US.

BACKGROUND: United Network for Organ Sharing (UNOS) allocation criteria changed in 2018 to accommodate the increased prevalence of patients on a ventricular assist device as a bridge to heart transplant and prioritize sicker people in anticipation of a heart graft. We aimed to assess the impact of patient age in the new allocation policy on mortality following heart transplantation. Secondary outcomes included the effect of age ≥70 on post-transplant events, including stroke, dialysis, pacemaker, and rejection requiring treatment. METHODS: The UNOS Registry was queried to identify patients who underwent heart transplants alone in the US between 2000 and 2021. Patients were divided into groups according to their age (over 70 and under 70 years old). RESULTS: Patients aged over 70 were more likely to require dialysis during follow-up, but less likely to experience rejection requiring treatment, compared with patients aged <70. Age ≥70 in the new allocation system was a significant predictor of 1-year mortality (adjusted HR: 1.41; 95% CI: 1.05-1.91; p = .024), but its effect on 5-year mortality was not significant after adjusting for potential confounders (adjusted HR: 1.27; 95% CI:.97-1.66; p = .077). Undergoing transplantation under the new allocation policy vs the old allocation policy was not a significant predictor of mortality in patients over 70 years old. CONCLUSIONS: Age ≥70 is a significant predictor of 1-year mortality following heart transplantation, but not at 5 and 10 years; however, the new allocation does not seem to have changed the outcomes for this group of patients.

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.

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.

Interventional cardiologists' perspectives and knowledge towards artificial intelligence.

BACKGROUND: Artificial intelligence (AI) is increasingly utilized in interventional cardiology (IC) and holds the potential to revolutionize the field. METHODS: We conducted a global, web-based, anonymous survey of IC fellows and attendings to assess the knowledge and perceptions of interventional cardiologists regarding AI use in IC. RESULTS: A total of 521 interventional cardiologists participated in the survey. The median age range of participants was 36 to 45 years, most (51.5%) practice in the United States, and 7.5% were women. Most (84.7%) could explain well or somehow knew what AI is about, and 63.7% were optimistic/very optimistic about AI in IC. However, 73.5% believed that physicians know too little about AI to use it on patients and most (46.1%) agreed that training will be necessary. Only 22.1% were currently implementing AI in their personal clinical practice, while 60.6% estimated implementation of AI in their practice during the next 5 years. Most agreed that AI will increase diagnostic efficiency, diagnostic accuracy, treatment selection, and healthcare expenditure, and decrease medical errors. The most tried AI-powered tools were image analysis (57.3%), ECG analysis (61.7%), and AI-powered algorithms (45.9%). Interventional cardiologists practicing in academic hospitals were more likely to have AI tools currently implemented in their clinical practice and to use them, women had a higher likelihood of expressing concerns regarding AI, and younger interventional cardiologists were more optimistic about AI integration in IC. CONCLUSIONS: Our survey suggests a positive attitude of interventional cardiologists regarding AI implementation in the field of IC.

Use of plaque modification microcatheters during percutaneous coronary interventions for chronic total occlusion: insights from the PROGRESS-CTO Registry.

Plaque modification microcatheters (PM) (Tornus [Asahi] and Turnpike Gold [Teleflex]) are devices that are mainly used to modify the cap or lesion and maintain good support in chronic total occlusion (CTO) percutaneous coronary artery intervention (PCI). We evaluated the frequency of use and outcomes of plaque modification microcatheters in an international multicenter registry. Plaque modification microcatheters were utilized in 242 cases (1.6%: Tornus in 51% and Turnpike Gold in 49%) with decreasing frequency over time (P-for-trend: 0.007 and 0.035, respectively). Technical and procedural success and the incidence of major cardiac adverse events were similar with Tornus and Turnpike Gold use. PM are infrequently utilized in CTO-PCI and are associated with high success and acceptable complication rates.

Emergency coronary artery bypass surgery after chronic total occlusion percutaneous coronary intervention: Insights from the PROGRESS-CTO registry.

BACKGROUND: Emergency coronary artery bypass surgery (eCABG) is a serious complication of chronic total occlusion (CTO) percutaneous coronary artery intervention (PCI). METHODS: We examined the incidence and outcomes eCABG among 14,512 CTO PCIs performed between 2012 and 2023 in a large multicenter registry. RESULTS: The incidence of eCABG was 0.12% (n = 17). Mean age was 68 ± 6 years and 69% of the patients were men. The most common reason for eCABG was coronary perforation (70.6%). eCABG patients had larger target vessel diameter (3.36 ± 0.50 vs. 2.90 ± 0.52; p = 0.003), were more likely to have moderate/severe calcification (85.7% vs. 45.8%; p = 0.006), side branch at the proximal cap (91.7% vs. 55.4%; p = 0.025), and balloon undilatable lesions (50% vs. 7.4%; p = 0.001) and to have undergone retrograde crossing (64.7% vs. 30.8%, p = 0.006). eCABG cases had lower technical (35.3% vs. 86.7%; p < 0.001) and procedural (35.3% vs. 86.7%; p < 0.001) success and higher in-hospital mortality (35.3% vs. 0.4%; p < 0.001), coronary perforation (70.6% vs. 4.6%; p < 0.001), pericardiocentesis (47.1% vs. 0.8%; p < 0.001), and major bleeding (11.8% vs. 0.5%; p < 0.001). CONCLUSIONS: The incidence of eCABG after CTO PCI was 0.12% and associated with high in-hospital mortality (35%). Coronary perforation was the most common reason for eCABG.

Iso-osmolar vs low-osmolar contrast agents for coronary optical coherence tomography: a blinded prospective randomized controlled study.

BACKGROUND: The impact of contrast type on coronary optical coherence tomography (OCT) imaging has received limited research. METHODS: We conducted a blinded, prospective, single-center, randomized, controlled crossover study comparing iso-osmolar contrast media (IOCM) with low-osmolar contrast media (LOCM) in patients undergoing clinically indicated coronary OCT imaging. Patients were randomly assigned to undergo OCT imaging with either IOCM or LOCM as the initial contrast medium. Following a washout period, a second run of OCT imaging of the same coronary vessel was performed using the other contrast medium. RESULTS: A total of 62 patients were randomized to IOCM first (n = 31) or LOCM first (n = 31). Mean patient age was 65.9 ± 11.2 years and 74.2% were male, with high prevalence of dyslipidemia (82.3%) and prior myocardial infarction (41.9%). Percutaneous coronary intervention was performed in 60 cases (96.8%) and the left anterior descending artery was the most common target vessel (53.3%). The contrast volume used for OCT imaging was similar for IOCM and LOCM (8.0 [6.9, 9.0] mL vs 8.0 [6.7, 9.0] mL; P = .89), as was the length of clear OCT images (70.0 [62.8, 74.0] mm for IOCM vs 70.0 [64.0, 74.0] mm for LOCM; P = .65). Electrocardiographic changes were observed in 11 runs with IOCM (ventricular repolarization changes in 9 runs and premature ventricular contractions [PVCs] in 2 runs) vs 12 runs with LOCM (ventricular repolarization changes in 9 runs and PVCs in 3 runs). CONCLUSIONS: The use of IOCM in coronary OCT is associated with similar contrast volume and clear imaging length when compared with LOCM.

Predictors of successful primary antegrade wiring in chronic total occlusion percutaneous coronary intervention.

BACKGROUND: Antegrade wiring is the most commonly used chronic total occlusion (CTO) crossing technique. METHODS: Using data from the PROGRESS CTO registry (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention; Clinicaltrials.gov identifier: NCT02061436), we examined the clinical and angiographic characteristics and procedural outcomes of CTO percutaneous coronary interventions (PCIs) performed using a primary antegrade wiring strategy. RESULTS: Of the 13 563 CTO PCIs performed at 46 centers between 2012 and 2023, a primary antegrade wiring strategy was used in 11 332 (83.6%). Upon multivariable logistic regression analysis, proximal cap ambiguity (odds ratio [OR]: 0.52; 95% CI, 0.46-0.59), side branch at the proximal cap (OR: 0.85; 95% CI, 0.77-0.95), blunt/no stump (OR: 0.52; 95% CI: 0.47-0.59), increasing lesion length (OR [per 10 mm increase]: 0.79; 95% CI, 0.76-0.81), moderate to severe calcification (OR: 0.73; 95% CI, 0.66-0.81), moderate to severe proximal tortuosity (OR: 0.67; 95% CI, 0.59-0.75), bifurcation at the distal cap (OR: 0.66; 95% CI, 0.59-0.73), left anterior descending artery CTO (OR [vs right coronary artery]: 1.44; 95% CI, 1.28-1.62) and left circumflex CTO (OR [vs right coronary artery]: 1.22; 95% CI, 1.07-1.40), non-in-stent restenosis lesion (OR: 0.56; 95% CI, 0.49-0.65), and good distal landing zone (OR: 1.18; 95% CI, 1.06-1.32) were independently associated with primary antegrade wiring crossing success. CONCLUSIONS: The use of antegrade wiring as the initial strategy was high (83.6%) in our registry. We identified several parameters associated with primary antegrade wiring success.

Update on chronic total occlusion percutaneous coronary intervention.

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) continues to evolve. This review summarizes recent publications categorized by outcomes, techniques, complications, and ongoing studies in this rapidly growing area.

Racial disparities in chronic total occlusion percutaneous coronary interventions: insights from the PROGRESS-CTO registry.

OBJECTIVES: There is limited data on race and outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). The authors sought to evaluate CTO PCI techniques and outcomes in different racial groups. METHODS: We examined the baseline characteristics and procedural outcomes of 11 806 CTO PCIs performed at 44 US and non-US centers between 2012 and March 2023. In-hospital major adverse cardiac events (MACE) included death, myocardial infarction, repeat target-vessel revascularization, pericardiocentesis, cardiac surgery, and stroke prior to discharge. RESULTS: The most common racial group was White (84.5%), followed by Black (5.7%), "Other" (3.9%), Hispanic (2.9%), Asian (2.4%), and Native American (0.7%). There were significant differences in the baseline characteristics between different racial groups. When compared with non-White patients, the retrograde approach and antegrade dissection re-entry were more likely to be the successful crossing strategies in White patients without any significant differences in technical success (86.4% vs 86.4%; P = .93), procedural success (84.8% vs 85.0%; P = .79), and in-hospital MACE (2.0% vs 1.5%; P = .15) between the 2 groups. The technical success rate was significantly higher in the "Other" racial group (91.0% vs 86.4% in White, 86.9% in Asian, 84.5% in Black, 84.5% in Hispanic, and 83.3% in Native American; P = .03) without any significant differences in procedural success or in-hospital MACE rates between the groups. CONCLUSIONS: Despite differences in baseline characteristics and procedural techniques, the procedural success and in-hospital MACE of CTO PCI were not significantly different between most racial groups.

Sex differences in the well-being of interventional cardiologists.

Several studies suggest differences in burnout and coping mechanisms between female and male physicians. We conducted an international, online survey exploring sex-based differences in the well-being of interventional cardiologists. Of 1251 participants, 121 (9.7%) were women. Compared with men, women were more likely to be single and under 50 years old, and they asked more often for development opportunities and better communication with administration. Overall burnout was similar between women and men, but women interventional cardiology attendings were more likely to think that they were achieving less than they should. Improved communication with administration and access to career development opportunities may help prevent or mitigate burnout in women interventional cardiologists.

Equipment entrapment/loss during chronic total occlusion percutaneous coronary intervention.

BACKGROUND: There is limited data on equipment loss or entrapment during chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We analyzed the baseline clinical and angiographic characteristics and outcomes of equipment loss/entrapment at 43 US and non-US centers between 2017 and 2023. RESULTS: Equipment loss/entrapment was reported in 40 (0.4%) of 10 719 cases during the study period. These included guidewire entrapment/fracture (n = 21), microcatheter entrapment/fracture (n = 11), stent loss (n = 8) and balloon entrapment/fracture/rupture (n = 5). The equipment loss/entrapment cases were more likely to have moderate to severe calcification, longer lesion length, higher J-CTO and PROGRESS-CTO complications scores, and use of the retrograde approach compared with the remaining cases. Retrieval was attempted in 71.4% of the guidewire, 90.9% of the microcatheter, 100% of the stent loss, and 100% of the balloon cases, and was successful in 26.7%, 30.0%, 50%, and 40% of the cases, respectively. Procedures complicated by equipment loss/entrapment had higher procedure and fluoroscopy time, contrast volume and patient air kerma radiation dose, lower procedural (60.0% vs 85.6%, P less than .001) and technical (75.0% vs 86.8%, P = .05) success, and higher incidence of major adverse cardiac events (MACE) (17.5% vs 1.8%, P less than .001), acute MI (7.5% vs 0.4%, P less than .001), emergency coronary artery bypass graft (CABG) (2.5% vs 0.1%, P = .03), perforation (20.0% vs 4.9%, P less than .001), and death (7.5% vs 0.4%, P less than .001). CONCLUSIONS: Equipment loss is a rare complication of CTO PCI; it is more common in complex CTOs and is associated with lower technical success and higher MACE.

Use of the Indigo CAT RX aspiration system during percutaneous coronary intervention.

BACKGROUND: The use of the Indigo CAT RX Aspiration System (Penumbra Inc.) during percutaneous coronary intervention has received limited study. METHODS: We retrospectively examined the clinical, angiographic, and procedural characteristics, outcomes, and follow-up of patients who underwent mechanical aspiration thrombectomy with the Indigo CAT RX system (Penumbra Inc.) at a large tertiary care hospital between January 2019 and April 2023. RESULTS: During the study period, 83 patients (85 lesions) underwent thrombectomy with the Indigo CAT RX. Mean patient age was 64.9 ± 14.48 years and 31.2% were women. The most common presentations were ST-segment elevation myocardial infarction (MI) (66.2%) and non-ST-segment elevation MI (26.5%). A final thrombolysis in MI flow grade of 3 and final myocardial blush grade of 3 were achieved in 76% and 46% of the cases, respectively. Technical success was achieved in 88.9% of the cases that included Indigo CAT RX treatment only, compared with 57.1% of the cases that also included manual aspiration. There were no device-related serious adverse events. At 30-day postprocedure, the incidence of major adverse cardiac events (composite of cardiovascular death, recurrent MI, cardiogenic shock, new or worsening New York Heart Association Class IV heart failure, stroke) was 8.5%: 1.3% stroke (postprocedure, in-hospital), 1.3% MI, 6.1% cardiac death, and 7.5% developed cardiogenic shock. CONCLUSIONS: Use of the Indigo CAT RX system is associated with high technical success and acceptable risk of complications, including stroke.