Full-moon coronary calcification as detected with computed tomography angiography in chronic total occlusion percutaneous coronary intervention

"Full moon" is a central calcification that occludes the entire vessel on coronary computed tomography angiography (CCTA). We examined the association of "full moon" calcification as identified by CCTA, on clinical and procedural outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We studied patients who underwent elective CTO PCI in two European centers and had pre-procedural CCTA. The primary endpoint was the inability to cross the lesion and/or the need for extensive debulking techniques. Secondary endpoints were procedural success, in-hospital cardiac mortality, the need for extensive debulking techniques, myocardial infarction (MI), major adverse cardiac events (MACE, defined as in hospital death, MI and clinically driven target vessel revascularization) and stent thrombosis. Secondary procedural endpoints included procedural time, fluoroscopy time, number of guidewires and balloons, stent length, number and diameter and contrast volume. Multivariable logistic regression analysis was performed identifying potential covariates related to the primary outcome according to knowledge and prior studies. Subsequently, a stepwise selection approach was performed to select factors with the greatest predictive value. Among 140 patients included, 28 (20%) had a "full moon" calcified CTO-plaque. Patients in the full moon group were older and had more cardiovascular risk factors. There was not significant difference in the need for retrograde approach and antegrade dissection and re-entry (ADR) techniques in the "full moon" group vs the other groups (32.1% vs 37.5%, p=0.59 and 0% vs 1.7%, p=0.47 respectively). Compared with patients who did not have full moon morphology, full moon patients had higher incidence of the primary outcome (53.5% vs 12.5%;p<0.001). On multivariable analysis that included chronic kidney failure and prior coronary artery bypass surgery, full moon calcification was associated with higher incidence of the primary endpoint; OR 6.5;95% CI 2.1-20.5;p=0.001). Moreover, lower procedural success (71.4% vs 87.5%;p=0.03), higher incidence of coronary perforations (14.2% vs 3.5%;p<0.02) and higher procedural [172.5 (118.0-237.5) vs 144.0 (108.50-174.75); p=0.02] and fluoroscopic time [62.6 (38.1-83.0) vs 42.8 (29.5-65.7); p=0.03] were observed in the "full moon" group. Overall MACE did not differ between the two groups (1 patient in the "full moon" group vs 1 patient in the no "full moon" group; 3.5% vs 0.8%, p=0.29). In conclusion, "full moon" calcification on CCTA was independently associated with procedural complexity and adverse outcomes in CTO-PCI.

Evaluation and management of patients with coronary chronic total occlusions considered for revascularisation. A clinical consensus statement of the European Association of Percutaneous Cardiovascular Interventions (EAPCI) of the ESC, the European Association of Cardiovascular Imaging (EACVI) of the ESC, and the ESC Working Group on Cardiovascular Surgery

Chronic total occlusions (CTOs) of coronary arteries can be found in the context of chronic or acute coronary syndromes; sometimes they are an incidental finding in those apparently healthy individuals undergoing imaging for preoperative risk assessment. Recently, the invasive management of CTOs has made impressive progress due to sophisticated preinterventional assessment, including advanced non-invasive imaging, the availability of novel and dedicated tools for CTO percutaneous coronary intervention (PCI), and experienced interventionalists working in specialised centres. Thus, it is crucial that referring physicians who see patients with CTO be aware of recent developments and of the initial evaluation requirements for such patients. Besides a careful history and clinical examination, electrocardiograms, exercise tests, and non-invasive imaging modalities are important for selecting the patients most suitable for CTO PCI, while others may be referred to coronary artery bypass graft or optimal medical therapy only. While CTO PCI improves angina and reduces the use of antianginal drugs in patients with symptoms and proven ischaemia, hibernation and/or wall motion abnormalities at baseline or during stress, the effect of CTO PCI on major cardiovascular events is still controversial. This clinical consensus statement specifically focuses on referring physicians, providing a comprehensive algorithm for the preinterventional evaluation of patients with CTO and the current evidence for the clinical effectiveness of the procedure. The proposed care track has been developed by members and with the support of the European Association of Percutaneous Cardiovascular Interventions (EAPCI), the European Association of Cardiovascular Imaging (EACVI), and the European Society of Cardiology (ESC) Working Group on Cardiovascular Surgery.

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.

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.

A case report on intravascular lithotripsy to facilitate retrograde wire passage from the subintimal to the luminal space in a calcified chronic total occlusion

Background

Severe calcifications are a major reason for failures in chronic total coronary occlusions, as they can obstruct the wire passage both in the antegrade and retrograde technique.

Case summary

The proximal occlusion of the left anterior descending artery in a 75-year-old man presented with a completely concentric calcified ring all along the segment proximal to the occlusion. The antegrade wire could not pass the calcified occlusion, and in a retrograde approach via the right posterior descending artery the retrograde wire was not able to enter the lumen from a subintimal position outside of the calcified ring. Intravascular lithoplasty in the proximal segment led to a crack in this ring to enable the same retrograde wire now to pass into the true lumen with then successful conclusion of the case. Intravascular ultrasound demonstrated the modification of the calcified ring and the passage of the wire with only a very short subintimal pathway.

Discussion

Intravascular lithoplasty is a new option to modify severely calcified vessel segments to facilitate the reverse controlled antegrade and retrograde tracking approach. In the present case, this helped to avoid a long subintimal pathway and preserved the vessel anatomy.

Three-year outcomes of A Randomized Multicentre Trial Comparing Revascularization and Optimal Medical Therapy for Chronic Total Coronary Occlusions (EuroCTO)

BACKGROUND

Percutaneous coronary intervention (PCI) for chronic total coronary occlusions (CTO) improves clinical symptoms and quality of life. The longer-term safety of PCI compared to optimal medical therapy (OMT) remains uncertain.

AIMS

We sought to evaluate the long-term safety of PCI for CTO in a randomised trial as compared to OMT.

METHODS

A total of 396 patients with a symptomatic CTO were enrolled into a randomised, multicentre clinical trial comparing PCI and OMT. Half of the patients had a single CTO; the others had multivessel disease. Non-CTO lesions were treated prior to randomisation (2:1 ratio). During follow-up, crossover from OMT to PCI occurred in 7.3% (1 year) and 17.5% (3 years) of patients.

RESULTS

At 3 years, the incidence of cardiovascular death or nonfatal myocardial infarction was not significantly different between the groups (OMT 3.7% vs PCI 6.2%; p=0.29). By per-protocol analysis, the difference remained non-significant (OMT 5.7% vs PCI 4.7%; p=0.67). Overall, major adverse cardiovascular events (MACE) were more frequent with OMT (OMT 21.2% vs PCI 11.2%), largely because of ischaemia-driven revascularisation. The rates of stroke or hospitalisation for bleeding were not different between the groups.

CONCLUSIONS

At 3 years there was no difference in the rate of cardiovascular death or myocardial infarction between PCI or OMT among patients with a remaining single coronary CTO. The MACE rate was higher in the OMT group due largely to ischaemia-driven revascularisation. CTO PCI appears to be a safe option for patients with a single remaining significant coronary CTO. CinicalTrials.gov: NCT01760083.

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.

Clinical and Procedural Outcomes of IVUS-Guided vs. Angiography-Guided CTO-PCI: A Systematic Review and Meta-Analysis

Chronic total occlusions (CTO) in coronary angiographies present a significant challenge nowadays. Intravascular ultrasound (IVUS) is a valuable tool during CTO-PCI, aiding in planning and achieving procedural success. However, the impact of IVUS on clinical and procedural outcomes in CTO-PCI remains uncertain. This meta-analysis aimed to compare IVUS-guided and angiography-guided approaches in CTO-PCI. The study included five studies and 2320 patients with stable coronary artery disease (CAD) and CTO. The primary outcome of major adverse cardiac events (MACE) did not significantly differ between the groups (p = 0.40). Stent thrombosis was the only secondary clinical outcome that showed a significant difference, favoring the IVUS-guided approach (p = 0.01). Procedural outcomes revealed that IVUS-guided procedures had longer stents, larger diameters, and longer procedure and fluoroscopy times (p = 0.007, p < 0.001, p = 0.03, p = 0.002, respectively). Stent number and contrast volume did not significantly differ between the approaches (p = 0.88 and p = 0.33, respectively). In summary, routine IVUS use did not significantly improve clinical outcomes, except for reducing stent thrombosis. Decisions in CTO-PCI should be individualized based on patient characteristics and supported by a multi-parametric approach.

Association of Successful Percutaneous Revascularization of Chronic Total Occlusions With Quality of Life: A Systematic Review and Meta-Analysis

Importance

Chronic total occlusion percutaneous coronary intervention (CTO-PCI) is not usually offered because of skepticism about long-term clinical benefits.

Objective

To assess the association of successful CTO-PCI with quality of life by analyzing the relevant domains of the Seattle Angina Questionnaire (SAQ).

Data Sources

PubMed, EMBASE, Web of Science, Google Scholar, and Cochrane databases were searched to identify randomized trials and observational studies specifically addressing quality of life domains of SAQ from January 2010 to June 2022.

Study Selection

Studies included reporting SAQ metrics such as angina frequency, physical limitation, and quality of life, before and after CTO-PCI.

Data Extraction and Synthesis

The present study was performed according to the Cochrane Collaboration and Preferred Reporting Items for Systematic Reviews and Meta-Analyses statements, in which fixed-effect or random-effect models with generic inverse-variance weighting depending on statistical homogeneity were applied. Data were extracted by 3 independent reviewers.

Outcomes and Measures

The primary outcome was angina frequency; physical limitation and quality of life were assessed as secondary outcomes.

Results

Seven prospective randomized or observational studies (2500 patients) were included, with a mean (SD) participant age of 61.2 (2.1) years. CTO-PCI was associated with significantly improved quality-of-life metrics during a mean (SD) follow-up of 14.8 (16.3) months. In patients with successful procedures, angina episodes became less frequent (mean [SD] difference for SAQ angina frequency of 12.9 [3.1] survey points [95% CI, 7.1-19.8 survey points]; standardized mean difference was 0.54 [95% CI, 0.21-0.92]; P = .002; I2 = 86.4%) and they experienced less physical activity limitation (mean [SD] difference for SAQ physical limitation of 9.7 [6.2] survey points [95% CI, 3.5-16.2 survey points]; standardized mean difference was 0.42 [95% CI, 0.24-0.55]; P < .001; I2 = 20.9%), and greater quality-of-life domain (mean [SD] difference for SAQ quality of life of 14.9 [3.5] survey points [95% CI, 7.7-22.5 survey points]; standardized mean difference was 0.41 [95% CI, 0.25-0.61]; P < .001; I2 = 58.8%) compared with patients with optimal medical therapy or failed procedure. Furthermore, follow-up duration (point estimate, 0.03; 95% CI, 0.01-0.04; P = .01) was associated with a significant decrease in angina frequency in meta-regression analysis.

Conclusions and Relevance

In this systematic review and meta-analysis examining quality of life following CTO-PCI, successful procedures were associated with improved quality-of-life parameters compared with patients on optimal medical therapy or after failed CTO-PCI. These findings suggest support for using PCI to treat CTOs in symptomatic patients unresponsive to medical treatment.

Anemia and periprocedural complications determine contrast-associated acute kidney injury after recanalization of chronic coronary occlusions in chronic kidney disease

BACKGROUND

Contrast-associated acute kidney injury (CA-AKI) is a potential risk associated with the percutaneous coronary interventions (PCI) for chronic total coronary occlusions (CTO) particularly with pre-existing chronic kidney disease (CKD). The determinants of CA-AKI in patients with pre-existing CKD in an era of advanced strategies of CTO recanalization techniques need to be considered for a risk evaluation of the procedure.

METHODS

A consecutive cohort of 2504 recanalization procedures for a CTO between 2013 and 2022 was analyzed. Of these, 514 (20.5%) were done in patients with CKD (estimated glomerular filtration rate < 60 ml/min based on the most recently used CKD Epidemiology Collaboration equation).

RESULTS

The rate of patients classified to have CKD would be lower with 14.2% using the Cockcroft-Gault equation, and 18.1% using the modified Modification of Diet in Renal Disease equation. The technical success was high with 94.9% and 96.8% (p = 0.04) between patients with and without CKD. The incidence of CA-AKI was 9.9% versus 4.3% (p < 0.001). The major determinants of CA-AKI in patients with CKD were the presence of diabetes and a reduced ejection fraction, as well as periprocedural blood loss, whereas a higher baseline hemoglobin and the use of the radial approach prevented CA-AKI.

CONCLUSIONS

In patients with CKD CTO PCI could be performed successfully at a higher cost of CA-AKI. Correcting preprocedural anemia and avoiding intraprocedural blood loss may reduce the incidence of CA-AKI.

Retrograde percutaneous coronary intervention of chronic total occlusion via discontinuous septal channels

OBJECTIVES

The study aims to investigate the safety and feasibility of retrograde CTO intervention via collateral connection grade 0 (CC-0) septal channel and to identify predictors of collateral tracking failure.

BACKGROUND

Guidewire crossing a collateral channel is a critical step for successful retrograde percutaneous coronary intervention (PCI) of chronic total occlusion (CTO).

METHODS

Retrograde PCI was attempted in 122 cases of CTO with CC-0 septal collaterals from December 2018 to May 2021. A hydrophilic polymer coating guidewire was used for crossing all intended CC-0 collaterals. A multivariable logistic regression analysis was performed to identify the predictors of guidewire tracking failure via the CC-0 collaterals.

RESULTS

Successful guidewire tracking via CC-0 septal channel was achieved in 98 (80.3%) of 122 cases. The independent predictors of CC-0 septal channel guidewire tracking failure included well-developed non-septal collateral (OR: 5.297, 95% CI: 1.107-25.353, p = 0.037) and the ratio length of posterior descending artery (PDA) versus the distance of PDA ostium to cardiac apex ≤2/3 (OR: 3.970, 95% CI: 1.454-10.835, p = 0.007). Collateral perforation, target vessel perforation, and cardiac tamponade occurred in 5 (4.1%), 3 (2.5%), and 6 (4.9%) cases, respectively. There were no complications requiring emergency cardiac surgery or revascularization of nontarget vessel.

CONCLUSIONS

Retrograde PCI via CC-0 septal channels with a hydrophilic polymer-coated guidewire is feasible and safe in patients with CTO. Well-developed nonseptal collaterals and short PDA length influence the procedure success and the risk of guidewire tracking failure via CC-0 septal channels.

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.

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.

521 IMPACT OF CORONARY COMPUTED TOMOGRAPHY ANGIOGRAPHY DERIVED “FULL MOON“ CALCIFICATIONS IN CHRONIC TOTAL OCCLUSION PERCUTANEOUS CORONARY INTERVENTIONS (CTO-PCI)

Background

There is an increasing incidence of chronic total coronary occlusions (CTO). CTO are complex coronary lesions and known to represent a technical challenge for percutaneous recanalization procedures. However, the success rates of CTO- percutaneous coronary interventions (CTO-PCI) have increased tremendously with the continuous innovations in equipment and procedural techniques.

Circular heavily calcified “Full Moon”- like plaques have been observed in CTO patients, however their frequency and relevance for CTO-PCI outcomes remain unclear, despite they can be straightforward identified by Coronary Computed Tomographic Angiography (CCTA) during CT-scans to select the CTO-PCI recanalization strategy.

Purpose

The aim of this study was to investigate the clinical value of CCTA – derived “Full Moon”-like plaques and to analyze its impact on percutaneous CTO recanalization.

Methods and Results

Out of the Charité CTO-PCI registry a total of 29 consecutive patients undergoing CTO-PCI and upstream CCTA-imaging for CTO planning were enrolled into the entire analysis. One patient was excluded due to stent artefacts with insufficient CCTA quality. Within the study cohort 17.9% (n=5) presented a “Full Moon”-like stenosis as CTO-causing target lesion. During CTO-PCI all these lesions (100%) required extensive debulking techniques as rotablation or ultrasound lithoplasty due to difficulties in device crossing compared to 13% (n=3) lesions in the non “Full Moon” group (p&lt;0.001).

In detail, 40% of lesions in the “Full Moon” group had to be prepared by rotablation-therapy (compared to 0% in the non- “Full Moon” group; p&lt;0.05) and 20% of lesions underwent shockwave therapy as compared to 13% non- “Full Moon” lesions (n=3; p=.0.69). However, 40% of the “Full Moon” interventions resulted in a complete failure of crossing the device compared to 13.0% in the non- “Full Moon” group (p=0.15).

Conclusions

: “Full Moon”- like calcification derived by CCTA represents a frequently observed phenomenon in CTO and represents an important predictor for complexity during CTO-PCI. Coronary Computed Tomography can be used to identify such a marker of calcium complexity and therefore to plan the procedure in advance.

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.

Automatic assessment of collaterals physiology in chronic total occlusions by means of artificial intelligence

BACKGROUND

Assessment of collaterals physiology in chronic total occlusions (CTO) currently requires dedicated devices, adds complexity, and increases the cost of the intervention. This study sought to derive collaterals physiology from flow velocity changes (ΔV) in donor arteries, calculated with artificial intelligence- aided angiography.

METHODS

Angiographies with successful percutaneous coronary intervention (PCI) in 2 centers were retro- spectively analyzed. CTO collaterals were angiographically evaluated according to Rentrop and collateral connections (CC) classifications. Flow velocities in the primary and secondary collateral donor arteries (PCDA, SCDA) were automatically computed pre and post PCI, based on a novel deep-learning model to extract the length/time curve of the coronary filling in angiography. Parameters of collaterals physiology, Δcollateral-flow (Δfcoll) and Δcollateral-flow-index (ΔCFI), were derived from the ΔV pre-post.

RESULTS

The analysis was feasible in 105 out of 130 patients. Flow velocity in the PCDA significantly decreased after CTO-PCI, proportionally to the angiographic collateral grading (Rentrop 1: 0.02 ± 0.01 m/s; Rentrop 2: 0.04 ± 0.01 m/s; Rentrop 3: 0.07 ± 0.02 m/s; p < 0.001; CC0: 0.01 ± 0.01 m/s; CC1: 0.04 ± ± 0.02 m/s; CC2: 0.06 ± 0.02 m/s; p < 0.001). Δfcoll and ΔCFI paralleled ΔV. SCDA also showed a greater reduction in flow velocity if its collateral channels were CC1 vs. CC0 (0.03 ± 0.01 vs. 0.01 ± 0.01 m/s; p < 0.001). For each individual patient, ΔV was more pronounced in the PCDA than in the SCDA.

CONCLUSIONS

Automatic assessment of collaterals physiology in CTO is feasible, based on a deeplearning model analyzing the filling of the donor vessels in angiography. The changes in collateral flow with this novel method are quantitatively proportional to the angiographic grading of the collaterals.

Comparative Analysis of Patient Characteristics in Chronic Total Occlusion Revascularization Studies: Trials vs Real-World Registries

BACKGROUND

The few randomized controlled trials (RCTs) on chronic total occlusion (CTO) percutaneous coronary intervention (PCI) are subject to selection bias.

OBJECTIVES

The purpose of this study was to evaluate the differences between real-world CTO patients and those enrolled in RCTs.

METHODS

This study performed a meta-analysis of national and dedicated CTO PCI registries and compared patient characteristics and outcomes with those of RCTs that randomized patients to CTO PCI versus medical therapy. Given the large sample size differences between RCTs and registries, the study focused on the absolute numbers and their clinical significance. The study considered a 5% relative difference between groups to be potentially clinically relevant.

RESULTS

From 2012 to 2022, 6 RCTs compared CTO PCI versus medical therapy (n = 1,047) and were compared with 15 registries (5 national and 10 dedicated CTO PCI registries). Compared with registry patients, RCT patients had fewer comorbidities, including diabetes, hypertension, previous myocardial infarction, and prior coronary artery bypass graft surgery. RCT patients had shorter CTO length (29.6 ± 19.7 mm vs 32.6 ± 23.0 mm, a relative difference of 9.2%) and lower Japan-Chronic Total Occlusion Score scores (2.0 ± 1.1 vs 2.3 ± 1.2, a relative difference of 13%) compared with those enrolled in dedicated CTO registries. Procedural success was similar between RCTs (84.5%) and dedicated CTO registries (81.4%) but was lower in national registries (63.9%).

CONCLUSIONS

There is a paucity of randomized data on CTO PCI outcomes (6 RCTs, n = 1,047). These patients have lower risk profiles and less complex CTOs than those in real-world registries. Current evidence from RCTs may not be representative of real-world patients and should be interpreted within its limitation.

CT-Guided CTO-PCI Overcoming Bypass Surgery-Induced Native Coronary Artery Tenting

Antegrade wire crossing of a mid calcified left anterior descending (LAD) artery was achieved. However, the wire was seen deflecting in a different pathway than the angiographically anticipated course of the vessel. Therefore, the computed tomography images were reanalyzed and the wire was seen to be within the tented site of the left internal mammary artery to the LAD anastomosis and correctly positioned according to the vessel course.

Procedural characteristics and outcomes following chronic total occlusion coronary intervention: pooled analysis from 5 registries

BACKGROUND

Recent improvements in clinical skills, technology, and hardware have resulted in improved success rates with chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We performed a study level pooled analysis from the five largest registries of percutaneous coronary intervention (PCI) of CTO.

RESEARCH DESIGN AND METHODS

We conducted pooled analysis of 9500 patients in registries and data on procedural characteristics, technical success, and MACCE was collected.

RESULTS

A total of 9500 patients were included in the analysis. Mean age was 65.4 years with previous CABG in 24.8%, reattempt procedure in 24.8% and mean JCTO score was 2.2. Final wiring strategy in hybrid algorithm-based registries was AWE in 40.8-58%, Retrograde in 24-35%, ADR in 16-25% and in Expert JCTO and EURO CTO was AWE in 72-75% and retrograde in 25-28%. Technical success was achieved in 87.8%. In hospital MACCE was 2.5% (95% CI: 1.8- 3.4%), mortality 0.44% (95% CI: 0.23-0.84%), stroke 0.2% (95% CI: 0.1-0.3%); myocardial infraction 1.6% (95% CI: 1.1-2.2%); and cardiac tamponade 0.8% (95% CI: 0.5 to 1.3%).

CONCLUSION

CTO PCI is currently performed with high technical success rates and low complication rates in experienced hands utilizing various techniques.

A prospective study on the incidence of contrast-associated acute kidney injury after recanalization of chronic total coronary occlusions with contemporary interventional techniques

BACKGROUND

Contrast-associated acute kidney injury (CA-AKI) is a potential risk associated with the percutaneous coronary interventions (PCI) for chronic total coronary occlusions (CTO). This study should evaluate the incidence of CA-AKI in an era of advanced strategies of recanalization techniques and identify modifiable determinants.

METHODS

We analysed 1924 consecutive CTO procedures in 1815 patients between 2012 and 2019. All patients were carefully monitored at least up to 48 h after a CTO procedure for changes in renal function.

RESULTS

The incidence of CA-AKI was 5.6%, but there was no relation to the technical approach such as frequency of the retrograde technique, intravascular ultrasound or radial access. Procedures with CA-AKI had longer fluoroscopy times (37.6 vs 46.1 min; p = 0.005). The major determinants of CA-AKI were age, presence of diabetes and reduced ejection fraction, as well as chronic kidney disease stage ≥2, serum haemoglobin, and fluoroscopy time. Contrast volume or contrast volume/GFR ratio were not independent determinants of CA-AKI. Periprocedural perforations were more frequent in CA-AKI patients (11.3 vs 2.3%; p < 0.001), and in-hospital mortality was higher (2.8 vs 0.4%; p < 0.001).

CONCLUSIONS

CA-AKI was associated with the risk of in-hospital adverse events. Established patient-related risk factors for CA-AKI (age, diabetes, preexisting chronic kidney disease, low ejection fraction) were confirmed in this study. In addition, the length of the procedure, coronary perforations and low preprocedural serum haemoglobin were risk factors that might be preventable in patients at high risk for CA-AKI.

Reducing fluoroscopic and cineangiographic contribution to radiation exposure for chronic total coronary occlusion interventions

BACKGROUND

The treatment of chronic total coronary occlusions (CTO) carries the highest radiation exposure among percutaneous coronary interventions (PCI). In order to minimize radiation damage, we need to understand and optimize the contribution of all components of radiation exposure.

METHODS

A total of 1000 CTO procedures performed between 2011 and 2020 were compared according to implemented radiation modifications. Group 1 used the original set-up of the X-ray equipment (Artis Zee, Siemens). In group 2 a modified protocol aimed at reducing the fluoroscopy exposure, in group 3 further modifications aimed at reducing cineangiographic exposure.

RESULTS

Despite an increased lesion complexity, Air Kerma (AK) was reduced from 2619 mGy (1653-4574) in group 1 to 2178 mGy (1332-3500; p < 0.001) in group 2 by mainly reducing fluoroscopic contribution by 54.1%, the cineangiographic contribution was lowered by only 6.6%. In group 3 AK dropped drastically to 746 mGy (480-1225; p < 0.001) mainly by reducing the cineangiographic contribution by 53.4%, still there was a further reduction of fluoroscopy contribution of 8.2%. This also led to a reduction of the skin entry dose from 1038 mGy (690-1589) in group 2 to 359 mGy (204-591; p < 0.001) in group 3. This was achieved both in normal weight and obese patients, and both in antegrade and retrograde procedures.

CONCLUSIONS

The present study demonstrates that by modifying both the fluoroscopic and cineangiographic contribution to radiation exposure a drastic reduction of radiation risk can be achieved, even in obese patients. Currently accepted radiation thresholds may no longer be a limit for CTO PCI.

Resolving chronic stent under-expansion in calcified lesions by intravascular lithoplasty

Severe coronary calcification is a common cause for stent under-expansion, which is associated with an increased risk of stent thrombosis and restenosis. Presently the devices for treatment of under-expanded stent due to severe calcification are rotational atherectomy and high-pressure non-compliant balloons with the limitation of potential balloon rupture and perforation risk. We report on a series of seven successful treatments of chronically under-expanded stents due to severe calcification using shockwave coronary intravascular lithoplasty (IVL). Our report suggests that IVL is a feasible and safe tool for such chronically under-expanded stents. <Learning objective: Severe coronary calcification is a common cause for stent under-expansion, which is associated with an increased risk of stent thrombosis and restenosis. Presently the devices for treatment of under-expanded stent due to severe calcification are rotational atherectomy and high-pressure non-compliant balloons. Our report suggests that intravascular lithoplasty is a feasible and safe tool to expand chronically under-expanded stents due to severe calcification, and that it is superior to rotational atherectomy and high-pressure balloons.>.

Radiation Exposure for Percutaneous Interventions of Chronic Total Coronary Occlusions in a Multicenter Registry: The Influence of Operator Variability and Technical Set-up

AIMS

Radiation exposure is a limiting factor for percutaneous coronary interventions (PCI) of chronic total coronary occlusion (CTO) lesions. This study was designed to analyze changes in patient radiation dose for CTO-PCI and parameters associated with radiation dose.

METHODS AND RESULTS

We analyzed a cohort of 12,136 procedures performed by 23 operators between 2012 and 2017 from the European Registry of CTO-PCI. Radiation exposure was recorded as air kerma (AK) and dose area product (DAP). A dose rate index (DRI) was calculated as AK per fluoroscopy time to normalize for individual differences in fluoroscopy time. The lesion complexity increased from Japanese-CTO (J-CTO) score of 2.19 ± 1.44 to 2.46 ± 1.28, with an increase of retrograde procedures from 31.1% to 40.7%; still, procedural success improved from 87.7% to 92.1%. Fluoroscopy time remained similar, but AK decreased by 14.9%, from 2.35 Gy (interquartile range [IQR], 1.29-4.14 Gy) to 2.00 Gy (IQR, 1.08-3.45 Gy) and DAP decreased by 21.5%, from 130 Gy•cm² (IQR, 70-241 Gy•cm²) to 102 Gy•cm² (IQR, 58-184 Gy•cm²). Radiation exposure was determined by the lesion complexity (J-CTO score) and procedural complexity (antegrade or retrograde). DRI was determined by fluoroscopy frame rate and type of equipment used, but the major influence remained interoperator differences.

CONCLUSIONS

Radiation exposure decreased during the observation period despite an increase in lesion and procedural complexity. While many operators already achieved a goal of low radiation exposure, there were considerable interoperator differences in radiation management, indicating further potential for improvement.

Definitions and Clinical Trial Design Principles for Coronary Artery Chronic Total Occlusion Therapies: CTO-ARC Consensus Recommendations

Over the past 2 decades, chronic total occlusion (CTO) percutaneous coronary intervention has developed into its own subspecialty of interventional cardiology. Dedicated terminology, techniques, devices, courses, and training programs have enabled progressive advancements. However, only a few randomized trials have been performed to evaluate the safety and efficacy of CTO percutaneous coronary intervention. Moreover, several published observational studies have shown conflicting data. Part of the paucity of clinical data stems from the fact that prior studies have been suboptimally designed and performed. The absence of standardized end points and the discrepancy in definitions also prevent consistency and uniform interpretability of reported results in CTO intervention. To standardize the field, we therefore assembled a broad consortium comprising academicians, practicing physicians, researchers, medical society representatives, and regulators (US Food and Drug Administration) to develop methods, end points, biomarkers, parameters, data, materials, processes, procedures, evaluations, tools, and techniques for CTO interventions. This article summarizes the effort and is organized into 3 sections: key elements and procedural definitions, end point definitions, and clinical trial design principles. The Chronic Total Occlusion Academic Research Consortium is a first step toward improved comparability and interpretability of study results, supplying an increasingly growing body of CTO percutaneous coronary intervention evidence.

Impact of intravascular ultrasound on chronic total occlusion percutaneous revascularization

AIM

We sought to investigate the impact of IVUS use on chronic total occlusion (CTO) PCI using data from a contemporary registry of consecutive patients and applying a propensity score matching analysis.

METHODS AND RESULTS

We evaluated 514 successful CTO-PCIs, median age: 67 years (IQR: 58-73), 83.5% males. IVUS-guided PCI was performed in 184 (35.8%) of cases. After using 1:1 propensity matching score analysis, two groups of 182 patients each (IVUS-guided vs. angiography-guided CTO-PCI group) were produced to form the study population. In the IVUS-guided group the median maximum stent diameter was larger and the median total stented segment was longer compared to the angiography-guided group [(3.5 mm, IQR: 3.0-4.0 vs. 3.2 mm, IQR: 3.0-3.5, p < 0.001) and (60.0 mm, IQR: 38.0-91.3 vs. 38.0 mm, IQR: 32.0-70.5, p < 0.001), respectively]. In the IVUS-guided group, retrograde recanalization was more frequently encountered compared to the angiography-guided PCI group (30.2% vs. 20.9%, p = 0.04). Procedural time was significantly longer in the IVUS-guided group, without any difference in fluoroscopy time, radiation dose and contrast volume. Multivariate linear regression analysis showed that IVUS use was the strongest independent factor associated with larger maximum diameter stents (p < 0.001) and a strong independent predictor for total stented segment length during CTO-PCI (p < 0.001). Up to 8 years follow-up, there was no difference in the incidence of the composite endpoint of all-cause death, cardiac death, myocardial infarction and target vessel revascularization between the IVUS-guided PCI and the angiography-guided PCI groups (hazard ratio: 13.7% vs. 15.9%, respectively, log-rank: p = 0.67, median follow-up time: 49.0 months, IQR: 33.0-67.0).

CONCLUSIONS

Use of IVUS in CTO-PCI was associated with larger stent diameter and longer stented segments. Despite more frequent use of IVUS in retrograde CTO-PCI, there was no difference in long-term adverse events between IVUS and angiography CTO-PCI groups; nevertheless, the study was not powered to assess clinical outcomes.

Latest developments in chronic total occlusion percutaneous coronary intervention

INTRODUCTION

Chronic Total Occlusion Percutaneous Coronary Intervention (CTO PCI) is now performed with high success rates and acceptable complication rates.

AREAS COVERED

We describe recent clinical and technological developments in CTO PCI from 2018 to 2020.

EXPERT OPINION

After publication of six randomized controlled trials, improving patient symptoms remains the principal indication for CTO PCI. Although good outcomes can be achieved with CTO PCI at experienced centers, success rates are significantly lower at less experienced centers, despite increased use in CTO crossing algorithms and development of novel and improved equipment and techniques.

CASTLE score versus J-CTO score for the prediction of technical success in chronic total occlusion percutaneous revascularisation

AIMS

We sought to compare the efficiency of the novel EuroCTO (CASTLE) score with the commonly used Multicentre CTO Registry in Japan (J-CTO) score in predicting procedural success of percutaneous coronary intervention (PCI) for coronary chronic total occlusions (CTOs).

METHODS AND RESULTS

We evaluated 660 consecutive CTO PCIs (mean age 66±11 years, 84% male). The mean J-CTO and EuroCTO (CASTLE) scores were 1.86±1.2 and 1.74±1.2, respectively. Antegrade wire escalation, antegrade dissection re-entry and retrograde approach were used in 82%, 14% and 37% of cases, respectively. Receiver operating characteristic analysis demonstrated equal overall discriminatory capacity between the two scores (AUC 0.698, 95% CI: 0.653-0.742, p<0.001 for J-CTO vs AUC 0.676, 95% CI: 0.627-0.725, p<0.001 for EuroCTO; AUC difference: 0.022, p=0.5). However, for more complex procedures (J-CTO ≥3 or EuroCTO [CASTLE] ≥4]), the predictive capacity of the EuroCTO (CASTLE) score appeared superior (AUC 0.588, 95% CI: 0.509-0.668, p=0.03 for EuroCTO [CASTLE] score vs AUC 0.473, 95% CI: 0.393-0.553, p=NS for the J-CTO score, AUC difference: 0.115, p=0.04).

CONCLUSIONS

In this study, the novel EuroCTO (CASTLE) score was comparable to the J-CTO score in predicting CTO PCI outcome with a superior discriminatory capacity for the more complex cases.

A randomized multicentre trial to compare revascularization with optimal medical therapy for the treatment of chronic total coronary occlusions

Aims

The clinical value of percutaneous coronary intervention (PCI) for chronic coronary total occlusions (CTOs) is not established by randomized trials. This study should compare the benefit of PCI vs. optimal medical therapy (OMT) on the health status in patients with at least one CTO.

Method and results

Three hundred and ninety-six patients were enrolled in a prospective randomized, multicentre, open-label, and controlled clinical trial to compare the treatment by PCI with OMT with a 2:1 randomization ratio. The primary endpoint was the change in health status assessed by the Seattle angina questionnaire (SAQ) between baseline and 12 months follow-up. Fifty-two percent of patients have multi-vessel disease in whom all significant non-occlusive lesions were treated before randomization. An intention-to-treat analysis was performed including 13.4% failed procedures in the PCI group and 7.3% cross-overs in the OMT group. At 12 months, a greater improvement of SAQ subscales was observed with PCI as compared with OMT for angina frequency [5.23, 95% confidence interval (CI) 1.75; 8.71; P = 0.003], and quality of life (6.62, 95% CI 1.78-11.46; P = 0.007), reaching the prespecified significance level of 0.01 for the primary endpoint. Physical limitation (P = 0.02) was also improved in the PCI group. Complete freedom from angina was more frequent with PCI 71.6% than OMT 57.8% (P = 0.008). There was no periprocedural death or myocardial infarction. At 12 months, major adverse cardiac events were comparable between the two groups.

Conclusion

Percutaneous coronary intervention leads to a significant improvement of the health status in patients with stable angina and a CTO as compared with OMT alone.

Trial registration

NCT01760083.

Outcomes with retrograde versus antegrade chronic total occlusion revascularization

OBJECTIVES

The aim of the study was to evaluate the outcomes of retrograde versus antegrade approach in chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

BACKGROUND

The retrograde approach has increased the success rate of CTO PCI but has been associated with a higher risk for complications.

METHODS

We conducted a meta-analysis of studies published between 2000 and August 2019 comparing the in-hospital and long-term outcomes with retrograde versus antegrade CTO PCI.

RESULTS

Twelve observational studies (10,240 patients) met our inclusion criteria (retrograde approach 2,789 patients, antegrade approach 7,451 patients). Lesions treated with the retrograde approach had higher J-CTO score (2.8 vs. 1.9, p < .001). Retrograde CTO PCI was associated with a lower success rate (80.9% vs. 87.4%, p < .001). Both approaches had similar in-hospital mortality, urgent revascularization, and cerebrovascular events. Retrograde CTO PCI was associated with higher risk of in-hospital myocardial infarction (MI; odds ratio [OR] 2.37, 95% confidence intervals [CI] 1.7, 3.32, p < .001), urgent pericardiocentesis (OR 2.53, 95% CI 1.41-4.51, p = .002), and contrast-induced nephropathy (OR 2.12, 95% CI 1.47-3.08; p < .001). During a mean follow-up of 48 ± 31 months retrograde crossing had similar mortality (OR 1.79, 95% CI 0.84-3.81, p = .13), but a higher incidence of MI (OR 2.07, 95% CI 1.1-3.88, p = .02), target vessel revascularization (OR 1.92, 95% CI 1.49-2.46, p < .001), and target lesion revascularization (OR 2.08, 95% CI 1.33-3.28, p = .001).

CONCLUSIONS

Compared with antegrade CTO PCI, retrograde CTO PCI is performed in more complex lesions and is associated with a higher risk for acute and long-term adverse events.

Temporal Trends in Chronic Total Occlusion Interventions in Europe

BACKGROUND

The study focuses on the evolution of practice, procedural outcomes, and in-hospital complications of chronic total occlusion percutaneous coronary intervention in Europe.

METHODS AND RESULTS

Data from 17 626 procedures enrolled in European Registry of Chronic Total Occlusion between January 2008 and June 2015 were assessed. The mean patient age was 63.9±10.9 years; 85% were men. Procedural success increased from 79.7% to 89.3% through the study period. Patients enrolled during the years had increasing comorbidities and lesion complexity (J-CTO score [Multicenter CTO Registry of Japan] increased from 1.76±1.03 in 2008 to 2.17±0.91 in 2015; P for trend, <0.001). Retrograde approach utilization steadily increased from 10.1% in 2008 to 29.9% in 2015 ( P for trend, <0.001). Antegrade dissection reentry adoption was low, not exceeding 5.5%. In-hospital mortality decreased during the study period from 0.4% to 0.1% ( P for trend, <0.001), whereas in-hospital complication rates remained essentially unchanged, in the range 4.4% to 5.2% ( P for trend, 0.390).

CONCLUSIONS

Chronic total occlusion percutaneous coronary intervention has shown a steady increase in procedural success rate over time, with unchanged complication rates, despite the increasing complexity of the lesions attempted. The J-CTO score predictive value for procedural success was low for the entire registry and had no predictive ability for the retrograde approach.

Impact of treatment delay on mortality in ST-segment elevation myocardial infarction (STEMI) patients presenting with and without haemodynamic instability: results from the German prospective, multicentre FITT-STEMI trial

Aims

The aim of this study was to investigate the effect of contact-to-balloon time on mortality in ST-segment elevation myocardial infarction (STEMI) patients with and without haemodynamic instability.

Methods and results

Using data from the prospective, multicentre Feedback Intervention and Treatment Times in ST-Elevation Myocardial Infarction (FITT-STEMI) trial, we assessed the prognostic relevance of first medical contact-to-balloon time in n = 12 675 STEMI patients who used emergency medical service transportation and were treated with primary percutaneous coronary intervention (PCI). Patients were stratified by cardiogenic shock (CS) and out-of-hospital cardiac arrest (OHCA). For patients treated within 60 to 180 min from the first medical contact, we found a nearly linear relationship between contact-to-balloon times and mortality in all four STEMI groups. In CS patients with no OHCA, every 10-min treatment delay resulted in 3.31 additional deaths in 100 PCI-treated patients. This treatment delay-related increase in mortality was significantly higher as compared to the two groups of OHCA patients with shock (2.09) and without shock (1.34), as well as to haemodynamically stable patients (0.34, P < 0.0001).

Conclusions

In patients with CS, the time elapsing from the first medical contact to primary PCI is a strong predictor of an adverse outcome. This patient group benefitted most from immediate PCI treatment, hence special efforts to shorten contact-to-balloon time should be applied in particular to these high-risk STEMI patients.

Clinical Trial Registration

NCT00794001.

Use of Coronary Computed Tomographic Angiography to Facilitate Percutaneous Coronary Intervention of Chronic Total Occlusions

Chronic total coronary occlusions (CTO) are found frequently in coronary artery disease; however, the technical challenge to open the occlusion by percutaneous coronary intervention is considerably higher than for nonocclusive lesions. The angiographic analysis is limited by the inability to visualize the occluded segment and requires a dual injection approach from donor and recipient vessel to assess the CTO. Therefore, imaging of the CTO by computed tomographic angiography can provide additional information on the vessel course within the CTO segment, specifically the degree and extent of calcification, and maybe even be superior to angiography to analyze the proximal cap morphology. This had been integrated in a score to predict the interventional success. This information provides a valuable means to better plan the procedure and the required strategy. In addition, an integration of the computed tomographic angiography is possible by synchronization with the gantry position and movement of the angiography system during percutaneous coronary intervention, illustrating the course of the occluded segment and possible obstacles in the way. It remains to be established which patient will most likely profit from this additional preprocedural examination involving increased radiation and contrast media exposure and institutional expenses.

Guiding Principles for Chronic Total Occlusion Percutaneous Coronary Intervention

Outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) have improved because of advancements in equipment and techniques. With global collaboration and knowledge sharing, we have identified 7 common principles that are widely accepted as best practices for CTO-PCI.  1. Ischemic symptom improvement is the primary indication for CTO-PCI.  2. Dual coronary angiography and in-depth and structured review of the angiogram (and, if available, coronary computed tomography angiography) are key for planning and safely performing CTO-PCI.  3. Use of a microcatheter is essential for optimal guidewire manipulation and exchanges.  4. Antegrade wiring, antegrade dissection and reentry, and the retrograde approach are all complementary and necessary crossing strategies. Antegrade wiring is the most common initial technique, whereas retrograde and antegrade dissection and reentry are often required for more complex CTOs.  5. If the initially selected crossing strategy fails, efficient change to an alternative crossing technique increases the likelihood of eventual PCI success, shortens procedure time, and lowers radiation and contrast use.  6. Specific CTO-PCI expertise and volume and the availability of specialized equipment will increase the likelihood of crossing success and facilitate prevention and management of complications, such as perforation.  7. Meticulous attention to lesion preparation and stenting technique, often requiring intracoronary imaging, is required to ensure optimum stent expansion and minimize the risk of short- and long-term adverse events. These principles have been widely adopted by experienced CTO-PCI operators and centers currently achieving high success and acceptable complication rates. Outcomes are less optimal at less experienced centers, highlighting the need for broader adoption of the aforementioned 7 guiding principles along with the development of additional simple and safe CTO crossing and revascularization strategies through ongoing research, education, and training.

Overview and proposed terminology for the reverse controlled antegrade and retrograde tracking (reverse CART) techniques

During recent years, equipment and techniques for percutaneous coronary intervention (PCI) of chronic total occlusions (CTO) have improved significantly. The retrograde approach remains critical to the improved success of CTO PCI. Currently, the reverse controlled antegrade and retrograde tracking (CART) technique has become the dominant retrograde wire crossing technique. In this article, we propose a standardised terminology and classification for this technique divided into three subtypes: a) conventional reverse CART, usually involving the use of large balloons on the antegrade wire to achieve re-entry within the CTO segment; b) "directed" reverse CART, which is characterised by small antegrade balloon size and more active, intentional vessel tracking and penetration with a controllable retrograde wire, still within the CTO segment; and c) "extended" reverse CART, in which the intimal/subintimal dissection is extended proximal or distal to the CTO segment, achieving re-entry outside the CTO segment. The proposed standardised terminology will facilitate the communication, teaching and adoption of the reverse CART techniques.