Safety and Effectiveness of a Novel Microcatheter in Coronary Chronic Total Occlusions-The BIOMICS Study.

Background: Chronic total occlusion (CTO) remains the most complex anatomical subset of lesions in percutaneous coronary intervention (PCI), often requiring advanced techniques and technologies, including the use of microcatheters. Methods: The BIOMICS study is a premarket first-in-human prospective, multicenter, open-label, single-arm trial investigating the safety and efficacy of a novel coronary microcatheter (BioMC, Biosensors International) in 100 patients with symptoms of ischemia undergoing elective CTO-PCI. The primary efficacy end point of the study was device success defined according to the CTO-ARC (Chronic Total Occlusion Academic Research Consortium) criteria namely the ability of the microcatheter to successfully facilitate placement of a guide wire beyond the occluded coronary segment. The primary safety end point was the incidence of in-hospital cardiac death or myocardial infarction at hospital discharge. Results: Hundred patients were recruited between March 2022 and January 2023. The primary efficacy end point was achieved in 75% of patients (95% CI, 65.3%-83.1%; P < .0001 for superiority compared to the prespecified performance goal of 54%). The primary safety end point of in-hospital cardiac death or myocardial infarction was observed in 2% of the patients. There were no study device-related coronary perforations or device failures. Conclusions: The use of a novel coronary microcatheter during CTO-PCI was associated with a high device success and an excellent safety profile.

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.

Complete vs. incomplete percutaneous revascularization in patients with chronic total coronary artery occlusion.

Introduction: There is current controversy surrounding the benefits of percutaneous coronary intervention (PCI) of chronic total coronary occlusions (CTO). We aimed to evaluate the impact of complete percutaneous revascularization on major adverse cardiovascular events (MACE) in patients with CTO. Methods: A retrospective observational study was conducted of consecutive patients referred for invasive coronary angiography at a single center between January 2018 and December 2019 and at least a CTO. The patients were divided into two groups according to the result of the procedure: complete revascularization of CTO (CR-CTO) versus incomplete revascularization (ICR-CTO) (patients with at least one non-recanalized CTO). Short- and mid-term clinical outcomes were evaluated. The primary endpoint was a composite of MACE that included all-cause death, non-fatal myocardial infarction, non-fatal stroke, or unplanned revascularization. Results: In total, 359 patients with CTO were included. The median age was 68 years [interquartile range (IQR) 60-77 years], 66 (18%) were women and 169 (47.3%) had diabetes mellitus. In all, 167 (46.5%) patients received complete revascularization. After a median follow-up of 42 months (IQR 46-50 months), the primary endpoint occurred in 39 (23.4%) patients in the CR-CTO group and in 75 (39.1%) in the ICR-CTO group (HR 0.50, 95% CI 0.34-0.74; p < 0.001). This association remained significant in an inverse probability weighted model considering prognostic factors (adjusted HR 0.61, 95% CI 0.41-0.92; p = 0.018) and was driven by lower rates of all-cause death (adjusted OR 0.50, 95% CI 0.23-0.84; p = 0.01). Conclusions: Complete revascularization of CTO was associated with a lower risk of MACE in the midterm follow up.

The synergistic effect of the atherogenic index of plasma and hyperuricemia on the prediction of coronary chronic total occlusion lesion: an observational cross-sectional study.

Background: The atherogenic index of plasma (AIP) and hyperuricemia (HUA) have been shown to be closely associated with morbidity and mortality of coronary artery disease. However, studies targeting predictive value of AIP and HUA for chronic total occlusion (CTO) lesions are still lacking. Methods: In total, 5,238 patients meeting the eligibility criteria were recruited in this analysis. CTO was defined as the condition of lesions without forward blood flow and with over three months of occlusion time. AIP was calculated as log10 [triglycerides (mmol/L)/high-density lipoprotein cholesterol (mmol/L)]. HUA was defined based on sex-specific criteria: serum uric acid 420 and 360 µmol/L for males and females, respectively. Results: CTO lesions were presented in 907 (17.3%) patients. Compared with patients showing lower AIP levels and non-HUA, the CTO lesion risks increased by 5.225 and 2.765 times in patients with higher AIP levels and HUA. Patients with AIP >0.15 and HUA exhibited the greatest CTO incidence (odds ratio 11.491; 95% confidence interval 9.019-14.641, P < 0.001). In addition, AIP combined with HUA had significantly increased effects (a 38.5% increase in CTO risk) relative to the sum of respective effects. Conclusion: Patients having higher AIP levels and HUA exhibited the highest CTO incidence, in comparison with patients who have the increased single index. AIP combined with HUA displayed significant synergistic effect on the prediction of CTO lesion.

Complete percutaneous coronary revascularization: An elegant solution to left ventricular dysfunction caused by severe coronary artery disease.

With increased complexity in both medical comorbidities and coronary anatomy, the proportion of surgically turndown patients and high-risk PCI will continue to rise. Impella-assisted complex PCI can be performed with high technical success and can improve quality of life, angina score, and potentially left ventricular ejection fraction.

Below-the-Ankle Antegrade Teleferic Technique: New Approach for Below-the-Ankle Revascularization in Challenging Cases of Chronic Limb-Threatening Ischemia.

PURPOSE: To describe a novel bailout technique to approach below-the-ankle (BTA) chronic total occlusions or plantar-arch severe disease where the balloon/catheter is unable to follow the crossing guidewire and no other described recanalization approach is feasible. TECHNIQUE: When facing a complex BTA revascularization, if the guidewire crosses but the balloon cannot progress due to a lack of pushability, an antegrade puncture of the infrapopliteal vessel where the tip of the guidewire lays is performed. The guidewire is then carefully navigated through this distal BTA vessel into the needle to achieve its rendezvous and externalization. A low-profile balloon is inserted through the femoral access and advanced till the non-crossable point of the BTA vessels. A torque device is then attached to the proximal hub of the balloon, and the through-and-through guidewire is subsequently pulled from the new distal access, allowing the balloon to be dragged across the lesion together with the wire. CONCLUSION: The below-the-ankle antegrade teleferic (BAT) technique may be considered for highly complex BTA revascularization procedures where the wire crosses the lesion, but no other device can be tracked over it. CLINICAL IMPACT: The clinical impact of this article lies in the description of a bailout technique for BTA revascularization where the guidewire crosses, but no device can be advanced. This technique can be helpful in scenarios where failure to achieve success could result in limb loss. The BAT technique provides a solution in extremely challenging cases, enhancing technical success, improving outcomes and potentially preserving the limbs of patients who would otherwise face amputation, if not revascularized.The video shows the BAT technique performed with a support catheter under fluoroscopy: antegrate puncture of the DP, advancement of the support catheter over the wire, rendezvous of the guidewire in the catheter and subsequent externalization of the wire.

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).

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.

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.

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.

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.

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.