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.

Contemporary outcomes of chronic total occlusion percutaneous coronary intervention in Europe: the ERCTO registry.

BACKGROUND: Percutaneous coronary interventions (PCI) of chronic total occlusions (CTO) have reached high procedural success rates thanks to dedicated equipment, evolving techniques, and worldwide adoption of state-of-the-art crossing algorithms. AIMS: We report the contemporary results of CTO PCIs performed by a large European community of experienced interventionalists. Furthermore, we investigated the impact of different risk factors for procedural major adverse cardiac and cerebrovascular events (MACCE) and trends of employment of specific devices like dual lumen microcatheters, guiding catheter extensions, intravascular ultrasound and calcium-modifying tools. METHODS: We evaluated data from 8,673 CTO PCIs included in the European Registry of Chronic Total Occlusion (ERCTO) between January 2021 and October 2022. RESULTS: The overall technical success rate was 89.1% and was higher in antegrade as compared with retrograde cases (92.8% vs 79.3%; p<0.001). Compared with antegrade procedures, retrograde procedures had a higher complexity of attempted lesions (Japanese CTO [J-CTO] score: 3.0±1.0 vs 1.9±1.2; p<0.001), a higher procedural and in-hospital MACCE rate (3.1% vs 1.2%; p<0.018) and a higher perforation rate with and without tamponade (1.5% vs 0.4% and 8.3% vs 2.1%, respectively; p<0.001). As compared with mid-volume operators, high-volume operators had a higher technical success rate in antegrade and retrograde procedures (93.4% vs 91.2% and 81.5% vs 69.0%, respectively; p<0.001), and had a lower MACCE rate (1.47% vs 2.41%; p<0.001) despite a higher mean complexity of the attempted lesions (J-CTO score: 2.42±1.28 vs 2.15±1.27; p<0.001). CONCLUSIONS: The adoption of different recanalisation techniques, operator experience and the use of specific devices have contributed to a high procedural success rate despite the high complexity of the lesions documented in the ERCTO.

Intravascular ultrasound-guided STAR 2.0: A new technique for chronic total occlusion recanalization.

The use of the subintimal space has allowed a massive advancement in the field of chronic total occlusion percutaneous coronary intervention (PCI). The STAR technique is the first of subintimal techniques. Despite a high acute success rate, follow-up results showed unfavorable outcomes with half of the treated patients showing restenosis/reocclusion at 6 months. We present three cases in which a modification of the STAR technique guided by intravascular ultrasound (IVUS), namely the STAR 2.0, was used as a bailout for successful PCI of chronic total occlusions.

A novel device for additional guide wire support to cross tortuous anatomy and tight lesions - the Micro Rx rapid exchange microcatheter.

Successful crossing of the target coronary lesion with a guidewire is an essential step in percutaneous coronary intervention. Guidewire advancement can be challenging, especially in tortuous, severely stenosed, and heavily calcified lesions. The use of a microcatheter significantly improves the guidewire steerability and penetration force, but it requires specific training and is associated with increased procedural costs. We present the first in vivo experience with a new type of rapid exchange microcatheter (Micro Rx, Interventional Medical Device Solutions), describe bench testing of combinations of guidewires and microcatheters, and suggest potential applications.

Coronary calcification in patients presenting with acute coronary syndromes: insights from the MATRIX trial.

AIMS: The role of coronary calcification on clinical outcomes among different revascularization strategies in patients presenting with acute coronary syndromes (ACSs) has been rarely investigated. The aim of this investigation is to evaluate the role of coronary calcification, detected by coronary angiography, in the whole spectrum of patients presenting with acute ACS. METHODS AND RESULTS: The present study was a post hoc analysis of the MATRIX programme. The primary endpoint was major adverse cardiovascular events (MACE), defined as the composite of all-cause mortality, myocardial infarction (MI), or stroke up to 365 days. Among the 8404 patients randomized in the MATRIX trial, data about coronary calcification were available in 7446 (88.6%) and therefore were included in this post hoc analysis. Overall, 875 patients (11.7%) presented with severe coronary calcification, while 6571 patients (88.3%) did not present severe coronary calcification on coronary angiography. Fewer patients with severe coronary calcification underwent percutaneous coronary intervention whereas coronary artery bypass grafting or medical therapy-only was more frequent compared with patients without severe calcification. At 1-year follow-up, MACE occurred in 237 (27.1%) patients with severe calcified coronary lesions and 985 (15%) patients without severe coronary calcified lesions [hazard ratio (HR) 1.91; 95% confidence interval (CI) 1.66-2.20, P < 0.001]. All-cause mortality was 8.6% in patients presenting with and 3.7% in those without severe coronary calcification (HR 2.38, 1.84-3.09, P < 0.001). Patients with severe coronary calcification incurred higher rate of MI (20.1% vs. 11.5%, HR 1.81; 95% CI 1.53-2.1, P < 0.001) and similar rate of stroke (0.8% vs. 0.6%, HR 1.35; 95% CI 0.61-3.02, P = 0.46). CONCLUSION: Patients with ACS and severe coronary calcification, as compared to those without, are associated with worse clinical outcomes irrespective of the management strategy.

Wire-based antegrade dissection re-entry technique for coronary chronic total occlusions percutaneous revascularization: Experience from the ERCTO Registry.

BACKGROUND: The recent development and widespread adoption of antegrade dissection re-entry (ADR) techniques have been underlined as one of the antegrade strategies in all worldwide CTO consensus documents. However, historical wire-based ADR experience has suffered from disappointing long-term outcomes. AIMS: Compare technical success, procedural success, and long-term outcome of patients who underwent wire-based ADR technique versus antegrade wiring (AW). METHODS: One thousand seven hundred and ten patients, from the prospective European Registry of Chronic Total Occlusions (ERCTO), underwent 1806 CTO procedures between January 2018 and December 2021, at 13 high-volume ADR centers. Among all 1806 lesions attempted by the antegrade approach, 72% were approached with AW techniques and 28% with wire-based ADR techniques. RESULTS: Technical and procedural success rates were lower in wire-based ADR than in AW (90.3% vs. 96.4%, p < 0.001; 87.7% vs. 95.4%, p < 0.001, respectively); however, wire-based ADR was used successfully more often in complex lesions as compared to AW (p = 0.017). Wire-based ADR was used in most cases (85%) after failure of AW or retrograde procedures. At a mean clinical follow-up of 21 ± 15 months, major adverse cardiac and cerebrovascular events (MACCEs) did not differ between AW and wire-based ADR (12% vs. 15.1%, p = 0.106); both AW and wire-based ADR procedures were associated with significant symptom improvements. CONCLUSIONS: As compared to AW, wire-based ADR is a reliable and effective strategy successfully used in more complex lesions and often after the failure of other techniques. At long-term follow-up, patient's MACCEs and symptoms improvement were similar in both antegrade techniques.

Coils embolization use for coronary procedures: Basics, indications, and techniques.

The use of coils is fundamental in interventional cardiology and can be lifesaving in selected settings. Coils are classified by their materials into bare metal, fiber coated, and hydrogel coated, or by the deliverability method into, pushable or detachable coils. Coils are delivered through microcatheters and the choice of coil size is important to ensure compatibility with the inner diameter of the delivery catheter, firstly to be able to deliver and secondly to prevent the coil from being stuck and damaged. Clinically, coils are used in either acute or in elective setting. The most important acute indication is typically the sealing coronary perforation. In the elective settings, coils can be used for the treatment of certain congenital cardiac abnormalities, aneurysms, fistulas or in the treatment of arterial side branch steal syndrome after CABG. Coils must always be delivered under fluoroscopy guidance. There are some associated complications with coils that can be acute or chronic, that nictitates regular followed-up. There is a need for education, training and regular workshops with hands-on to build the experience to use coils in situations that are infrequently encountered.

CTO and Bifurcation Lesions: An Expert Consensus From the European Bifurcation Club and EuroCTO Club.

Knowledge in the field of bifurcation lesions and chronic total occlusions (CTOs) has progressively improved over the past 20 years. Therefore, the European Bifurcation Club and the EuroCTO Club have decided to write a joint consensus statement to share general knowledge and practical approaches in this complex field. When percutaneously treating CTOs, bifurcation lesions with relevant side branches (SBs) are found in approximately one-third of cases (35% at the proximal cap, 38% at the distal cap, and 27% within the CTO body). Occlusion of a relevant SB is not rare and has been shown to be associated with procedural complications and adverse outcomes. Simple bifurcation rules are very useful to prevent SB occlusion, and provisional SB stenting is the recommended approach in the majority of cases: protect the SB as soon as possible by wiring it, respect the fractal anatomy of the bifurcation by using the 3-diameter rule, and avoid using dissection and re-entry techniques. A systematic 2-stent approach can be used if needed or sometimes to connect both branches of the bifurcation. The retrograde approach can be very useful to save a relevant SB, especially in the case of a bifurcation at the distal cap or within the CTO body. Intravascular ultrasound is also a very important tool to address the difficulties with bifurcations at the proximal or distal cap and sometimes also within the CTO segment. Double-lumen microcatheters and angulated microcatheters are crucial tools to resolve access difficulties to the SB or the main branch.

Utility of Guiding Catheter Extensions for Recanalization of Chronic Total Occlusions: A EuroCTO Club Expert Panel Report.

Guiding catheter extensions (GCEs) have become indispensable tools in the modern approach to percutaneous coronary intervention (PCI). The support offered during complex PCI of uncrossable, or tortuous lesions is particularly valuable in the setting of chronic total occlusions (CTO), both for conventional anterograde wire escalation and for anterograde or retrograde dissection and re-entry techniques. This EuroCTO consensus document describes the use of GCE during CTO recanalization and provides a practical guide to anatomies and techniques in which these devices are applicable. We describe the peculiar features of the most-used device and the practical technique for GCE delivery in standard PCI; further specific indications for antegrade and retrograde CTO PCI are discussed in a specific section. In the antegrade approach, the GCEs may be useful to increase support or facilitate antegrade dissection and re-entry techniques, while in the retrograde approach for reverse controlled antegrade and retrograde tracking, to increase retrograde support for gear delivery, for treatment of CTO in bifurcation and ipsilateral externalization with a single guide catheter. The last section of the paper describes GCE-related complications, challenges, limitations, and future perspectives.

Contemporary issues of percutaneous coronary intervention in heavily calcified chronic total occlusions: an expert review from the European CTO Club.

Severe calcification is frequent in coronary chronic total occlusions (CTO), and its presence has been associated with increased procedural complexity and poor long-term outcomes following percutaneous coronary intervention (PCI) in an already challenging anatomical setting. The diagnostic characterisation of heavily calcified CTOs using non-invasive and invasive imaging tools can lead to the application of different therapeutic options during CTO PCI, in order to achieve adequate lesion preparation and optimal stent implantation. In this expert review, the European Chronic Total Occlusion Club provides a contemporary, methodological approach, specifically addressing heavily calcified CTOs, suggesting an integration of evidence-based diagnostic methods to tailored, up-to-date percutaneous therapeutic options.

Gender differences in percutaneous coronary intervention for chronic total occlusions from the ERCTO study.

BACKGROUND: Gender-specific data addressing percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) in female patients are scarce and based on small sample size studies. AIMS: We aimed to analyze gender-differences regarding in-hospital clinical outcomes after CTO-PCI. METHODS: Data from 35,449 patients enrolled in the prospective European Registry of CTOs were analyzed. The primary outcome was the comparison of procedural success rate in the two cohorts (women vs. men), defined as a final residual stenosis less than 20%, with Thrombolysis In Myocardial Infarction grade flow = 3. In-hospital major adverse cardiac and cerebrovascular events (MACCEs) and procedural complications were deemed secondary outcomes. RESULTS: Women represented 15.2% of the entire study population. They were older and more likely to have hypertension, diabetes, and renal failure, with an overall lower J-CTO score. Women showed a higher procedural success rate (adjusted OR [aOR] = 1.115, confidence interval [CI]: 1.011-1.230, p = 0.030). Apart from previous myocardial infarction and surgical revascularization, no other significant gender differences were found among predictors of procedural success. Antegrade approach with true-to-true lumen techniques was more commonly used than retrograde approach in females. No gender differences were found regarding in-hospital MACCEs (0.9% vs. 0.9%, p = 0.766), although a higher rate of procedural complications was observed in women, such as coronary perforation (3.7% vs. 2.9%, p < 0.001) and vascular complications (1.0% vs. 0.6%, p < 0.001). CONCLUSIONS: Women are understudied in contemporary CTO-PCI practice. Female sex is associated with higher procedural success after CTO-PCI, yet no sex differences were found in terms of in-hospital MACCEs. Female sex was associated with a higher rate of procedural complications.

A Systematic Review and Meta-Analysis of Clinical Outcomes of Patients Undergoing Chronic Total Occlusion Percutaneous Coronary Intervention.

OBJECTIVES: Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) can improve patient symptoms, but it remains controversial whether it impacts subsequent clinical outcomes. METHODS: In this systematic review and meta-analysis, we queried PubMed, ScienceDirect, Cochrane Library, Web of Science, and Embase databases (last search: September 15, 2021). We investigated the impact of CTO-PCI on clinical events including all-cause mortality, cardiovascular death, myocardial infarction (MI), major adverse cardiovascular event (MACE), stroke, subsequent coronary artery bypass surgery, target-vessel revascularization, and heart failure hospitalizations. Pooled analysis was performed using a random-effects model. RESULTS: A total of 58 publications with 54,540 patients were included in this analysis, of which 33 were observational studies of successful vs failed CTO-PCI, 19 were observational studies of CTO-PCI vs no CTO-PCI, and 6 were randomized controlled trials (RCTs). In observational studies, but not RCTs, CTO-PCI was associated with better clinical outcomes. Odds ratios (ORs) and 95% confidence intervals (CIs) for all-cause mortality, MACE, and MI were 0.52 (95% CI, 0.42-0.64), 0.46 (95% CI, 0.37-0.58), 0.66 (95% CI, 0.50-0.86), respectively for successful vs failed CTO-PCI studies; 0.38 (95% CI, 0.31-0.45), 0.57 (95% CI, 0.42-0.78), 0.65 (95% CI, 0.42-0.99), respectively, for observational studies of CTO-PCI vs no CTO-PCI; 0.72 (95% CI, 0.39-1.32), 0.69 (95% CI, 0.38-1.25), and 1.04 (95% CI, 0.46-2.37), respectively for RCTs. CONCLUSIONS: CTO-PCI is associated with better subsequent clinical outcomes in observational studies but not in RCTs. Appropriately powered RCTs are needed to conclusively determine the impact of CTO-PCI on clinical outcomes.

Recanalisation of coronary chronic total occlusions.

Percutaneous treatment of coronary chronic total occlusions (CTO) has advanced greatly since its advent in the late 1970s through the development of dedicated wires and microcatheters, the improved skills of highly experienced operators and the adoption of new sophisticated strategies to guide procedural planning. The contemporary procedural success rate is 80-90% with a reduction in complications. Although there has been no improvement in prognosis in randomised trials to date, they, and other controlled registries of thousands of patients, confirm the pivotal role of CTO recanalisation in the treatment of angina and dyspnoea and an improvement in quality of life. Despite this evidence, CTO recanalisation is grossly underutilised. This review reports a detailed overview of the history, indications and treatment strategies for CTO recanalisation and hopes to increase interest among new, and especially young, operators in this demanding, rapidly evolving field of interventional cardiology.

Impact of Successful Chronic Coronary Total Occlusion Recanalization on Recurrence of Ventricular Arrhythmias in Implantable Cardioverter-Defibrillator Recipients for Ischemic Cardiomyopathy (VACTO PCI Study).

BACKGROUND: Coronary chronic total occlusion lesions (CTOs) confer an increased risk of arrhythmic events among patients with ischemic cardiomyopathy (ICM) and implantable cardioverter-defibrillator (ICD) carriers, however the impact of CTO recanalization in this population remains unassessed. AIMS: Evaluate the impact of CTOs percutaneous coronary interventions (PCI) on arrhythmic events. METHODS: Patients with ICM and ICD from the VACTO I-II registries: patients with medically treated CTO (CTO-OMT group) and without CTO (no-CTO group) were compared after inverse-probability-weighting adjustment (IPWT) with a similar population of consecutive patients undergoing CTO-PCI. The primary endpoint was appropriate ICD therapy. The secondary endpoint was all-cause mortality. RESULTS: The total of 622 patients (mean age 67 ± 10 years, mean left ventricular ejection fraction 36 ± 11%) included in the analysis was composed by: CTO-PCI patients n = 113, CTO-OMT patients n = 286, no-CTO patients n = 223. In the CTO-PCI group, compared to the CTO-OMT group, 5-year Kaplan Meier estimates for appropriate ICD therapy (20.4% vs. 56.4%, IPW-adjusted HR: 0.45, 95% CI 0.29-0.71) and mortality (8.8% vs. 23%, IPW-adjusted HR: 0.43, 95% CI 0.22-0.85) were lower, driven by infarct related artery CTO (IRA-CTO) PCI, while similar to those occurring in the no-CTO group. CONCLUSIONS: In this large population, those with CTO receiving PCI had lower arrhythmic event rates and lower mortality compared to the CTO-OMT group, while showing an event rate similar to no-CTO patients. Sensitivity analyses suggest that the beneficial effect on the arrhythmic outcome was driven by IRA-CTO revascularization. CLASSIFICATION: Chronic total occlusion.

Retrograde Chronic Total Occlusion Percutaneous Coronary Interventions: Predictors of Procedural Success From the ERCTO Registry.

OBJECTIVES: The aim of this study was to identify independent predictors of procedural success after retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI). BACKGROUND: Retrograde CTO PCI is an established technique, but predictors of success remain poorly understood. METHODS: A multivariable logistic regression model was used to analyze potentially important demographic, clinical, anatomical, and technical aspects of retrograde CTO PCI cases uploaded to the multicenter European CTO (ERCTO) Club Registry. RESULTS: In calendar years 2018 and 2019, 2,364 retrograde CTO PCI cases constituted the primary analysis cohort. A primary retrograde strategy was used in 1,953 cases (82.6%), and an initial antegrade approach was converted to retrograde in 411 cases (17.4%). Procedural success was achieved in 1,820 cases (77.0%) and was more likely to occur after a primary retrograde attempt versus conversion from an initial antegrade approach (80.9% vs 58.4%; P < 0.0001). After multivariable analysis, an absence of lesion calcification (OR: 1.86; 95% CI: 1.37-2.51; P < 0.0001), a higher degree of distal vessel opacification (OR: 2.47; 95% CI: 1.72-3.55; P < 0.0001), little or no proximal target vessel tortuosity (OR: 1.84; 95% CI: 1.28-2.64; P = 0.001), Werner collateral connection CC1 (OR: 4.87; 95% CI: 2.90-8.19; P < 0.0001) or CC2 (OR: 5.33; 95% CI: 3.02-9.42; P < 0.0001), and the top tertile of operator volume (>120 cases over 2 years) (OR: 1.88; 95% CI: 1.26-2.79; P = 0.002) were associated with the greatest chance of achieving angiographic success. CONCLUSIONS: Less calcification with good distal vessel opacification, little or absent proximal vessel tortuosity, and visible collateral connections, along with high-volume operator status, were all independently predictive of angiographically successful retrograde CTO PCI.

Device entrapment during percutaneous coronary intervention.

INTRODUCTION: Device entrapment is a life-threatening complication during percutaneous coronary intervention (PCI). However, the success for its management is predominantly based on operator experience with limited available guidance in the published literature. METHODS: A systematic review was performed on December 2021; we searched PubMed for articles on device entrapment during PCI. In addition, backward snowballing (i.e., review of references from identified articles and pertinent reviews) was employed. RESULTS: A total of 4209 articles were retrieved, of which 150 studies were included in the synthesis of the data. A methodical algorithmic approach to prevention and management of device entrapment can help to optimize outcomes. The recommended sequence of steps are as follows: (a) pulling, (b) trapping, (c) snaring, (d) plaque modification, (e) telescoping, and (f) surgery. CONCLUSIONS: In-depth knowledge of the techniques and necessary tools can help optimize the likelihood of successful equipment retrieval and minimization of complications.

Power Flush, a Novel Bailout Technique for Stumpless Aorto-Ostial CTOs: A Case-Based Approach.

BACKGROUND: Aorto-ostial coronary artery flush chronic total occlusions are a challenging subset of lesion with peculiar characteristic: the near complete lack of guiding catheter support, the presence of a thicker layer of muscular fibers and a greater collagen and calcium content, responsible for balloon dilatation's resistance and greater recoil tendency. We introduce a novel bailout technique to overcome retrograde wire failure in accessing aorta, a variation of the Carlino technique which we named Power Flush. MATERIALS AND METHODS: Power Flush consists in a forceful injection of contrast dye directly through the guiding catheter positioned against the aortic wall in correspondence to the coronary ostium location, to gain access to the extra-plaque space and proceed with the vessel's recanalization. In one case we used a further iteration named Nick And Flush, in which a preliminary nicking of the aortic wall with a penetrative wire was done before the Power Flush. RESULTS: We hereby present three cases of aorto-ostial right coronary artery flush chronic total occlusions. In two of them we utilized the Power Flush technique, in one case we employed its variant Nick And Flush. We were successful in all cases and no complication occurred. CONCLUSIONS: In this kind of lesions Power Flush and Nick And Flush are effective bailout techniques to overcome retrograde wire failure to reach aorta.

The last resort during complex retrograde percutaneous coronary chronic total occlusion intervention: Extraplaque intracoronary lithotripsy to externally crush a heavy calcified occluded stent.

Chronic total occlusions (CTO) due to in-stent restenosis represent a challenging lesion subset for percutaneous coronary intervention in particular when associated with coronary calcification. Sometimes CTO lesions require antegrade or retrograde dissection-re-entry techniques with extraplaque dilation. Recently intravascular lithotripsy (IVL) emerged as a therapeutic option for the treatment of severely calcified coronary lesions but its role in extraplaque dilation is not described. In this report, we present a case of retrograde complex percutaneous coronary chronic total occlusion revascularization accomplished by the use of extraplaque IVL necessary to externally crush a heavy calcified previous implanted stent.