High-Resolution Iodine-Enhanced Micro-Computed Tomography of Intact Human Hearts for Detailed Coronary Microvasculature Analyses.

Identifying the detailed anatomies of the coronary microvasculature remains an area of research; one needs to develop methods for non-destructive, high-resolution, three-dimensional imaging of these vessels for computational modeling. Currently employed Micro-Computed Tomography (Micro-CT) protocols for vasa vasorum analyses require organ dissection and, in most cases, non-clearable contrast agents. Here, we describe a method developed for a non-destructive, economical means to achieve high-resolution images of the human coronary microvasculature without organ dissection. Formalin-fixed human hearts were cannulated using venogram balloon catheters, which were then fixed into the specimen's aortic root. The canulated hearts, protected by a polyethylene bag, were placed in radiolucent containers filled with insulating polyurethane foam to reduce movement. For vasculature staining, iodine potassium iodide (IKI, Lugol's solution; 6.3% Potassium Iodide, 4.1% Iodide) was injected. Contrast distributions were monitored using a North Star Imaging X3000 micro-CT scanner with low-radiation settings, followed by high-radiation scanning (3600 rad, 60 kV, 900 mA) for the final high-resolution imaging. We successfully imaged four intact human hearts presenting with chronic total coronary occlusions of the right coronary artery. This imaging enabled detailed analyses of the vasa vasorum surrounding stenosed and occluded segments. After imaging, the hearts were cleared of iodine and excess polyurethane foam and returned to their initial formalin-fixed state for indefinite storage. Conclusions: the described methodologies allow for the non-destructive, high-resolution micro-CT imaging of coronary microvasculature in intact human hearts, paving the way for detailed computational 3D microvascular reconstructions with a macrovascular context.

The Ramus Intermedius: A Bridge to Survival in the Setting of Triple-Vessel Total Occlusion.

Coronary artery disease continues to remain the leading cause of mortality worldwide. Coronary blood supply is provided through the right and left main coronary arteries. The left main coronary artery (LMCA) in turn gives rise to the left anterior descending (LAD) and left circumflex (LCX) arteries. In some cases, LMCA may trifurcate into the ramus intermedius (RI) in addition to the LAD and LCX arteries. Atherosclerotic plaque formation and rupture with subsequent clot formation and occlusion of coronary arteries are the underlying mechanisms of myocardial infarction. Though the clinical implications of the presence of ramus intermedius (RI) are controversial some data suggest that the RI is associated with an increased risk of atherosclerotic plaque formation in the LMCA and the proximal LAD. Conversely, it has been proposed that the RI provides an additional collateral source of blood supply to the myocardium and may potentially contribute to improved survival. Case reports tout the benefits of RI, specifically in the setting of multivessel coronary artery occlusions. Whether it increases the risk of atherosclerotic plaque formation or whether it is protective has yet to be determined. We present a case of a 58-year-old male who presented with acute coronary syndrome and cardiogenic shock due to total ostial occlusion of LAD. The patient had also chronic total occlusions of the right coronary artery and LCX but a patent RI, which was the only source of blood supply to the myocardium and practically determined the patient's survival. Additionally, we performed a literature review to identify similar cases, to support RI's potentially protective role in enhancing survival.

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.

Predictors of outcomes after PCI with incomplete revascularization: Impact of CTO and LAD vessel.

BACKGROUND: Incomplete revascularization (ICR) after percutaneous coronary intervention (PCI) is associated with mortality and morbidity. AIM: We sought to investigate whether ICR in the left anterior descending artery (LAD) is worse than ICR of the right coronary artery (RCA) or left circumflex artery (LCX); and whether ICR in patients with a chronic total occlusion (CTO) is worse than in those without. METHODS: In the RIVER-PCI trial, 2651 patients with ICR after PCI were randomly assigned to ranolazine or placebo. Angiograms were assessed at an independent core laboratory in 2501 patients (94.3%). The primary endpoint was the composite of ischemia-driven revascularization or hospitalization. RESULTS: A total of 1664 patients (66.5%) had ICR involving the LAD, whereas 837 (33.5%) had ICR limited to the RCA or LCX. At median follow-up of 643 days, the primary endpoint occurred in 26.9% versus 26.5% of patients (adjusted HR [aHR]: 1.03, 95% confidence interval [CI]: 0.88-1.21). A nonrecanalized CTO was present in 854 patients (34.1%) with ICR after PCI. The primary endpoint occurred in 28.6% versus 25.9% of ICR patients with versus without a CTO (aHR: 1.10, 95% CI: 0.94-1.29). However, patients with a CTO had higher rates of ischemia-driven hospitalization without revascularization (aHR: 1.27, 95% CI: 1.04-1.56), heart failure hospitalization (aHR: 2.69, 95% CI: 1.61-4.59) and myocardial infarction (aHR: 1.46, 95% CI: 1.11-1.92) compared with those without. CONCLUSIONS: The 2-year prognosis was similar in post-PCI patients with ICR whether the LAD was versus was not involved. ICR patients with a CTO had more frequent hospitalizations for ischemia and myocardial infarctions compared with those without.

Impact of coronary collateralization on major adverse cardiovascular and cerebrovascular events after successful recanalization of chronic total occlusion.

Aims: This study aims to investigate the effects of coronary collateral circulation (CCC) on the prognosis of chronic total occlusion (CTO) patients with or without metabolic syndrome (MetS). Methods: The study included 342 CTO patients who underwent successful percutaneous coronary intervention at the People's Hospital of Liaoning Province between 1 February 2021 and 30 September 2023. The Rentrop score was used to assess the status of CCC. The outcome was major adverse cardiovascular and cerebrovascular events (MACCEs), defined as a composite of all-cause mortality, cardiac death, non-fatal myocardial infarction (MI), target vessel revascularization (TVR), and non-fatal stroke. Univariate and multivariate logistic analyses were used to investigate the association of CCC, MetS, and MACCEs with odds ratios (ORs) and 95% confidence intervals (CIs). The effect of CCC was further investigated in different MetS, diabetes mellitus (DM), and Syntax score groups. Results: MACCEs were more common in patients with poor CCC compared to those with good CCC (38.74% vs. 16.56%). Statistical differences were found in MACCEs (OR = 3.33, 95% CI: 1.93-5.72), MI (OR = 3.11, 95% CI: 1.73-5.58), TVR (OR = 3.06, 95% CI: 1.70-5.53), and stent thrombosis (OR = 6.14, 95% CI: 2.76-13.65) between the good and poor CCC groups. Poor CCC patients with MetS had a higher incidence of MACCEs (OR = 4.21, 95% CI: 2.05-8.65), non-fatal MI (OR = 4.44, 95% CI: 2.01-9.83), TVR (OR = 3.28, 95% CI: 1.51-7.11), and stent thrombosis (OR = 10.80, 95% CI: 3.11-37.54). Similar findings were also observed in CTO patients with DM and a Syntax score ≥23. Conclusion: Poor CCC could increase the risk of MACCEs in CTO patients, particularly those with MetS, DM, and a Syntax score ≥23. Further prospective, multicenter studies are needed to validate our findings and to explore potential therapeutic interventions.

Introduction of novel intravascular ultrasound preceding with angled guiding catheter (I-PAD) technique to treat chronic total occlusions in peripheral artery disease.

BACKGROUND: The optimal endovascular treatment (EVT) for chronic total occlusion (CTO) lesions in patients with peripheral artery disease (PAD) has remained unestablished. We encountered a patient with PAD in whom CTO was successfully treated using a novel technique that involved intravascular ultrasound (IVUS) and angled guiding catheter: IVUS Preceding with Angled guiDing catheter (I-PAD) technique. CASE PRESENTATION: A 74-year-old male presented with intermittent claudication attributed to CTO of the right external iliac artery. EVT was performed via the right common femoral artery. We retrogradely advanced the I-PAD system (i.e. partially extending the IVUS transducer portion from the tip of the angled guiding catheter) in the CTO lesion under the real-time guidance of IVUS imaging. We successfully traversed the CTO lesion without the use of a guidewire in approximately three minutes. The procedure concluded successfully without any procedure-related complications, following optimal stenting. CONCLUSIONS: The I-PAD might be an effective technique to accurately, quickly, and safely pass through CTO lesions.

2D array imaging system for mechanically-steered, forward-viewing ultrasound guidewire.

Approximately 4 million people with peripheral artery disease (PAD) present with critical limb ischemia each year, requiring urgent revascularization to avoid loss of limb. Minimally-invasive (i.e. endovascular) revascularization is preferable due to increased recovery time and increased risk of complications associated with open surgery. However, 40% of people with PAD also have chronic total occlusions (CTOs), resulting in > 20% of revascularization procedures failing when CTOs are present. A steerable robotic guidewire with integrated forward-viewing imaging capabilities would allow the guidewire to navigate through tortuous vasculature and facilitate crossing CTOs in revascularization procedures that currently fail due to inability to route the guidewire. The robotic steering capabilities of the guidewire can be leveraged for 3D synthetic aperture imaging with a simplified, low element count, forward-viewing 2D array on the tip of the mechanically-steered guidewire. Images can then be formed using a hybrid beamforming approach, with focal delays calculated for each element on the tip of the guidewire and for each physical location to which the robotically-steered guidewire is steered. Unlike synthetic aperture imaging with a steerable guidewire having only a single element transducer, an array with even a small number of elements can allow estimation of blood flow and physiological motion in vivo. A miniature, low element count 2D array transducer with 9 total elements (3 × 3) having total dimensions of 1.5 mm × 1.5 mm was designed to operate at 17 MHz. A proof-of-concept 2D array transducer was fabricated and characterized acoustically. The developed array was then used to image a wire target, a peripheral stent, and an ex vivo porcine iliac artery. Images were formed using the described synthetic aperture beamforming strategy. Acoustic characterization showed a mean resonance frequency of 17.6 MHz and a -6 dB bandwidth of 35%. Lateral and axial resolution were 0.271 mm and 0.122 mm, respectively, and an increase in SNR of 4.8 dB was observed for the 2D array relative to the single element case. The first 2D array imaging system utilizing both mechanical and electronic steering for guidewire-based imaging was developed and demonstrated. A 2D array imaging system operating on the tip of the mechanically-steered guidewire provides improved frame rate and increases field of view relative to a single element transducer. Finally, 2D array and single element imaging were compared for introduced motion errors, with the 2D array providing a 46.1% increase in SNR, and 58.5% and 17.3% improvement in lateral and axial resolution, respectively, relative to single element guidewire imaging.

Association between the atherogenic index of plasma and coronary collateral circulation in patients with chronic total occlusion.

BACKGROUND: The atherogenic index of plasma (AIP) is considered an independent risk factor for coronary artery disease (CAD). The present study investigated whether AIP correlates with the formation of coronary collateral circulation (CCC) in CAD patients with chronic total occlusion (CTO). METHODS: This retrospective study included 1093 CAD patients with CTO confirmed by coronary angiography from January 2020 to December 2020 at Beijing Anzhen Hospital. Based on the Rentrop scoring system, the patients were divided into the good CCC group and the poor CCC group. AIP was calculated by log (triglyceride/high-density lipoprotein cholesterol). Meanwhile, the study population was further divided into four groups according to the quartiles of AIP. RESULTS: Patients in the poor CCC group exhibited significantly higher AIP compared to those in the good CCC group (0.31 ± 0.27 vs. 0.14 ± 0.24, p < 0.001). Multivariate logistic regression analysis revealed an independent association between AIP and poor CCC, regardless of whether AIP was treated as a continuous or categorical variable (p < 0.001), after adjusting for confounding factors. Besides, this association remained consistent across most subgroups. The incorporation of AIP into the baseline model significantly enhanced the accuracy of identifying poor CCC [area under the curve (AUC): baseline model, 0.661 vs. baseline model + AIP, 0.721, p for comparison < 0.001]. CONCLUSIONS: Elevated AIP is independently associated with an increased risk of poor CCC in CAD patients with CTO, and AIP may improve the ability to identify poor CCC in clinical practice.

Mechanisms of Medial Wall Thinning in Chronic Total Occlusion.

BACKGROUND: The success rate of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) is lower and the risk for complications higher compared with other non-CTO PCI. Although interventionalists focus on intimal plaque characteristics, the coronary media is an important (especially for techniques involving antegrade dissection and re-entry) but poorly understood structure in CTO PCI. OBJECTIVES: The aim of the present study was to investigate coronary medial wall thinning in CTO lesions and determine how this thinning might affect CTO PCI. METHODS: A total of 2,586 sections were investigated, from arteries with evidence of CTO from 54 subjects (1,383 sections) and arteries without evidence of CTO from 54 subjects with non-coronary-related deaths (1,203 sections) after matching for age, gender, body weight, and body height. RESULTS: The medial thickness in subjects with CTO was lower than that in those with non-coronary-related death (P < 0.001). In subjects with CTO, CTO lesions had thinner medial walls compared with those with lower luminal narrowing (P < 0.001). At the CTO distal segments, the 6- to 12-mm distal segment from the distal end of the CTO had significantly less luminal narrowing (P < 0.001), and similar medial thickness, compared with the distal end of the CTO. Immunohistochemical analysis revealed that short-duration CTO had more cleaved caspase-3-positive cells in media and had significantly more CD3+, CD4+, CD8+, and CD4+CD28null T cells compared with long-duration CTO. CONCLUSIONS: CTO lesions demonstrated coronary medial thinning compared with non-CTO lesions. Further investigation of the cause-and-effect relationship among inflammation, apoptosis, and coronary medial wall thinning is warranted in future mechanistic studies.

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.

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 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.

Clinical validity of the Japanese below-the-knee chronic total occlusion scoring system for the prediction of successful guidewire crossing.

OBJECTIVE: To validate Japanese below-the-knee (J-BTK) chronic total occlusion (CTO) score for the prediction of successful guidewire crossing in angiographic evaluation. METHODS: A prospective, multicenter, non-randomized study examined 751 consecutive BTK CTOs in 497 patients treated with endovascular therapy (EVT) in 16 Japanese medical centers from April 2021 to March 2022. The cohort was classified into 2 groups: a successful guidewire crossing (S-GC) group and a failed guidewire crossing group. RESULTS: The J-BTK CTO score which assigned one point to "Blunt type at the proximal entry point", one point to "Calcification at the proximal entry point", one point to "Reference vessel diameter < 2.0mm", one point to "CTO length ≥ 200mm", and two points to "No outflow of the target vessel" was utilized to categorize BTK CTOs into 4 grades with varying probabilities of successful guidewire crossing: grade A (J-BTK CTO score of 0 and 1), grade B (score of 2 and 3), grade C (score of 4 and 5), and grade D (score of 6). Rates of successful guidewire crossing in each grade (grade A, B, C, and D) were 97.5%, 89.1%, 62.5%, and 27.3%, respectively. The area under the receiver-operating characteristic (ROC) curve for successful guidewire crossing was 0.8304. Although the previous J-BTK CTO study enrolled only de novo lesions, both de novo and restenotic lesions were evaluated in this study. De novo lesions have a lower chance of S-GC (odds ratio: 0.24, 95% confidence interval: 0.09-0.67) in the multivariate analysis and the area under the ROC curve of the modified J-BTK CTO score, which additionally assigned two points to "De novo lesion", was 0.846. The modified J-BTK CTO score showed an appropriate calibration (Hosmer-Lemeshow p=0.957). CONCLUSION: The J-BTK CTO score and the modified J-BTK CTO score predict the probability of a S-GC of BTK CTOs and stratify the difficulty of EVT for BTK CTOs in angiographic evaluation.

The impacts of percutaneous coronary intervention to treat chronic total occlusion of right coronary artery on the 5-year prognosis: A single-centered retrospective study.

BACKGROUND: Chronic total occlusions (CTO) occur in about 20% of patients referred for coronary angiography, and right coronary artery (RCA) CTO has been reported in 38-50% of the entire CTO population. Limited data on angiographic and procedural characteristics of RCA-CTO and the risk of adverse cardiac events asks for a detailed study. METHODS: From 2010 to 2013, patients with attempted revascularization of at least one CTO lesion were included and followed up to 5 years after PCI. Eligible patients are assigned to RCA-CTO and non-RCA-CTO groups based on their target vessels. The primary endpoint was major adverse cardiovascular events (MACEs; a composite of all-cause death, myocardial infarction (MI) or rehospitalization for heart failure), and secondary endpoints were cardiac death, target lesion revascularization (TLR) and target vessel revascularization (TVR). RESULTS: The present study included 2659 eligible patients, among which 1285 patients were assigned to the RCA-CTO group, whereas 1374 patients were assigned to the non-RCA-CTO group. Lesions in RCA had longer lesion length, higher J-CTO score, higher rates of severe vessel tortuosity, a higher percentage of Rentrop grade 2-3, and more likely to be re-try lesion than those in LAD or LCX (all P < 0.01). CTO lesions in RCA reached less successful recanalization and post-procedural TIMI 3 flow (all <0.01). Multivariate Cox analysis revealed that RCA-CTO was not associated with primary outcome MACEs. Besides MACEs, RCA-CTO was also not associated with cardiac death, but was significantly associated with TLR and TVR (adjusted HR: 1.37 [95% CI:1.07-1.76], P = 0.01; adjusted HR: 1.43 [95% CI:1.13-1.82], P = 0.003). CONCLUSION: RCA-CTO lesions, which had more complex angiographic features, independently contributed to TLR and TVR but not to MACEs or cardiac death in the 5 years of follow-up.

Who Should Undergo CTO PCI and When?: An Evidence-Based Approach to the Patient Referred for Percutaneous Coronary Intervention of Chronic Total Occlusion.

Chronic total occlusions (CTO) of the coronary arteries are common among patients presenting to the cardiac catheterization laboratory, and data suggests a worse overall prognosis in patients with CTOs. Percutaneous coronary intervention (PCI) of CTOs has been shown to improve anginal symptoms in observational studies and in a limited number of randomized trials. However, CTO PCI has not been shown to lead to a reduction in other important endpoints such as myocardial infarction or death. Further, despite recent advances in the field, CTO PCI still carries higher risks and a lower likelihood of success when compared with non-CTO PCI. Thus, determining which patients may be appropriate for CTO PCI is challenging, and must involve a comprehensive risk-benefit analysis and discussion with the patient. To this end, we review the currently available data regarding CTO PCI, including the clinical outcomes, role of preprocedural ischemia testing, and various procedural success and risk stratification scores. Finally, we present our approach to the patient referred for CTO PCI.

Development and validation of a nomogram for major adverse cardiovascular events after chronic total occlusion percutaneous coronary intervention for ischemic heart failure.

BACKGROUND: Chronic total occlusion percutaneous coronary intervention (CTO-PCI) is an available means of revascularization in patients with ischemic heart failure (IHF). However, the prognosis of IHF patients undergoing CTO-PCI remains unclear due to the lack of reliable clinical predictive tools. AIM: This study aimed to establish a nomogram for major adverse cardiovascular events (MACE) after CTO-PCI in IHF patients. METHODS: Sixty-seven potential predictive variables for MACE in 560 IHF patients undergoing CTO-PCI were screened using least absolute shrinkage and selection operator regression. A nomogram was constructed based on multivariable Cox regression to visualize the risk of MACE, and then evaluation was carried out using the concordance index (C-index), time-independent receiver operating characteristic (timeROC) curves, calibration curves, and decision curve analysis (DCA). RESULTS: During a median follow-up of 32.0 months, there were 208 MACE occurrences. Seven variables were selected for nomogram construction: age, left ventricular ejection fraction, left ventricular end-diastolic diameter, N-terminal precursor B-type diuretic peptide, bending, and use of intravascular ultrasound and beta-blockers. The C-index was 0.715 (0.680-0.750) and the internal validation result was 0.715 (0.676-0.748). The timeROC area under the curve at 6 months, 1 year, and 2 years was 0.750 (0.653-0.846), 0.747 (0.690-0.804), and 0.753 (0.708-0.798), respectively. The calibration curves and DCA showed the nomogram had acceptable calibration and clinical applicability. CONCLUSIONS: We developed a simple and efficient nomogram for MACE after CTO-PCI in IHF patients, which helps in early risk stratification and postoperative management optimization.

Bailout subintimal trans-catheter withdrawal (STRAW) technique for a distally extended coronary hematoma.

A coronary hematoma, which can sometimes obstruct coronary flow, may be left behind after tip-detection antegrade dissection and reentry. We present a novel bailout technique utilizing subintimal trans-catheter withdrawal technique with the assistance of a stent and a balloon. This technique can be used before performing bailout long stenting or a fenestration procedure with a cutting balloon, which are standard treatments for hematoma, to improve impaired coronary flow caused by a distally extended hematoma.

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).

Effectiveness and safety of a novel modified homemade snare in retrograde percutaneous coronary intervention for chronic total occlusion lesions: a retrospective cohort study.

Background: The use of a commercial snare for retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is time-consuming and expensive. This study aimed to evaluate the benefits and complications of a novel modified homemade snare (MHS) for retrograde CTO-PCI. Methods: This retrospective cohort study included patients with CTO who underwent retrograde PCI with guidewire snaring between January 2017 and June 2022 at Beijing Anzhen Hospital. The patients were divided into the MHS and gooseneck snare (GS) groups according to the devices used for externalization. Clinical, procedural, and angiographic data were collected. Results: Ninety patients (46 with MHS and 44 with GS) were included. There was no significant difference in the location of the CTO vessel between the MHS and GS groups, and the target CTO vessel was mainly located in the right coronary artery (RCA) in both groups (73.9% and 68.2% respectively). There were no significant differences in the J-CTO (Multicenter CTO Registry in Japan) and PROGRESS-CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention) scores between the two groups. More patients in the MHS group had lesions with ambiguous proximal caps compared with the GS group (54.3% vs. 31.8%, P=0.04). Retrograde wire crossing technique was used more in the GS group (54.5% vs. 41.3%, P=0.04), while reverse-controlled antegrade and retrograde subintimal tracking (CART) technique was used more in the MHS group (58.7% vs. 45.5%, P=0.037). The mean guidewire capture time was shorter in the MHS group than in the GS group (2.7±0.6 vs. 3.4±0.7 min, P<0.001). One case of delayed pericardial tamponade was observed in the MHS group. No other complications occurred. Conclusions: MHS appears to facilitate externalization in retrograde PCI for complex CTO lesions.

Ten tips and tricks for successful distal true lumen wiring from three-dimensional wiring experts.

Antegrade wiring is the dominant method used in chronic total occlusion percutaneous coronary intervention (CTO PCI). However, distal cap puncture for distal true lumen wiring remains a significant barrier toward success. Three-dimensional (3D) fluoroscopic wiring can improve the speed, safety, and success of distal cap wiring. In this article, we provide 10 tips for every CTO interventionist to use when performing 3D wiring in distal true lumen wiring.