Intravascular Healing Is Not Affected by Approaches in Contemporary CTO PCI: The CONSISTENT CTO Study

Give it time to SOBER up - GITSU- a new strategy in percutaneous coronary intervention for chronic total occlusion

BACKGROUND

The prevalence of coronary chronic total occlusion (CTO) in coronary angiography (CAG) has risen with ageing populations, along with the expansion of CTO percutaneous coronary interventions (CTO-PCI). However, CTO-PCI encounters challenges such as undersized stents, dissection risks, and limited access to intravascular imaging (IVI), particularly in regions with limited health budgets. This study introduces the 'GIVE IT TIME TO SOBER UP - GITSU strategy', a two-session CTO-PCI approach where Thrombolysis in Myocardial Infarction (TIMI-3) antegrade flow is achieved without stent placement in the first session. We aim to present its key attributes, outcomes, and implications for invasive cardiology.

METHODS

Demographic data, CTO lesion characteristics in the first PCI session, procedural features, in-hospital major adverse cardiovascular adverse events (MACE), technical features of the second PCI session, and in-hospital MACE were examined.

RESULTS

We applied the GITSU strategy to 53 CTO lesions between August 2020 and June 2023. The mean lesion length was shortened compared to the first session (21.3 ± 10.5%). There was an increase in mean distal reference vessel diameter (2.52 ± 0.49 mm), and the increase was 24.2%±11.3% compared to the first session. There was 24.4%±11.5% stent length savings. We achieved an increase in stent size of 20.3% to 10.1% compared to the mean stent diameter. The technical success and procedural success rate were 92.5% and 90.6%, respectively.

CONCLUSION

Patients who underwent GITSU used shorter and wider stents in the second PCI session. This strategy is likely to reduce TLR and ISR rates.

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.

Impact of aging on long-term cardiac outcomes of true-lumen recanalized chronic total occlusions in patients with overweight/obesity

BACKGROUND

Obesity paradox addressing all-cause mortality has been described in several chronic total occlusion (CTO) studies. However, the impact of aging on long-term cardiac events in patients with overweight and obesity with CTO recanalization were less studied.

METHODS

A total of 458 patients (64.4 ± 11.3 years, 403 male) with CTO interventions were enrolled. The overweight/obesity group included 311 patients with body mass index (BMI) ≧24 kg/m2 and the non-obesity group included 147. With a median follow-up of 40.0 (17.9-61.4) months, 422 patients with successful true-lumen recanalization were further assessed for target lesion failure [TLF: cardiac death, target vessel myocardial infarction (TVMI), target lesion revascularization (TLR)].

RESULTS

At follow-up, the rates of cardiac death, TVMI, TLR, TLF, and stent thrombosis were 1.9%, 1.9%, 9.2%, 10.7%, and 0.5%, respectively. The TVMI-free survival was borderline better (p = 0.067 by log-rank test) in overweight/obesity than non-obesity group. Among patients <65 years of age, the TVMI-free survival was significantly better in the overweight/obesity group (p = 0.013 compared to non-obesity group by log-rank test). In multivariate Cox regression model, the non-obesity patients younger than 65 years were at a higher risk of TVMI, not only among those <65 years of age (hazard ratio = 11.0, 95% CI = 1.1-106.0) but also among the whole patients (hazard ratio=6.9, 95% CI = 1.4-35.1) with successful CTO recanalization.

CONCLUSIONS

For those with true-lumen recanalized CTO, the higher risk of TVMI after successful recanalization was rather evident in patients <65 years of age and without overweight/obesity, suggesting that aging might attenuate prognostic significance of "obesity paradox" for CTO interventions.

Role of calcification in J-CTO score: a viewpoint of intraplaque guidewire tracking techniques

BACKGROUND

As the burden and distribution of calcification within chronic total occlusion (CTO) lesions can be diverse, its effect on CTO recanalization using multiple devices and techniques is debatable. This study investigated the role of calcification in wiring-based intraplaque tracking techniques for CTO recanalization.

METHODS

A modified J-CTO score without counting calcification was used to analyze the procedures of 458 consecutive patients who underwent CTO interventions. Failed guidewire crossing and intraplaque tracking were considered procedural failures. Recanalization time details were analyzed for successful procedures.

RESULTS

In patients with calcified CTO, the rate of procedural success only significantly declined to be lower than that of noncalcified CTO when the modified J-CTO score was ≥3 (77% vs. 94%, p = 0.008). In 422 patients with successful procedures, the presence of calcification was irrelevant to guidewire crossing time, but was accompanied with longer time from guidewire cross to final angiogram when the modified J-CTO score was 1-2 (53 ± 35 vs. 35 ± 17 [noncalcified] min, p < 0.001). Multivariate analyses showed that calcification was independently associated with procedural failure (odds ratio [OR] = 5.1, 95% confidence interval [CI] = 1.4-18.3) in lesions with modified J-CTO ≥3, and prolonged angioplasty/stenting procedures >60 min (OR = 4.8, 95% CI = 2.2-10.2) in successfully recanalized lesions with modified J-CTO score 1-2.

CONCLUSIONS

Using intraplaque guidewire tracking, calcification was unfavorable for very difficult CTO lesions, and caused prolongation of angioplasty time for lesions with moderate complexity. This suggested that the role of calcification in the J-CTO score could be altered when different recanalization techniques were applied for CTO interventions.

Knuckle Guidewires to Create Dissections in Chronic Total Occlusion Percutaneous Coronary Intervention: Position Statement

Dissection and re-entry techniques are essential to achieve safe and effective chronic total occlusion recanalization. Several studies have demonstrated similar outcomes following extraplaque stenting compared with intraplaque stenting. Dissection techniques most often involve the use of knuckled wires to progress within and beyond the chronic total occlusion segment. In this expert consensus document, the authors compare the properties of different polymer-jacketed wires for their use in dissection techniques. The authors also describe 2 principal knuckle wire behaviors, the rolling and the traveling knuckles. Finally, several adjunctive techniques for safer dissection are described.

Dissection and Re-entry Techniques for Chronic Total Occlusion Percutaneous Coronary Intervention

Despite early stagnation in success rates for percutaneous coronary intervention for chronic total occlusion with the traditional antegrade wiring approach, the introduction of dissection/re-entry techniques and the retrograde approach opened new avenues for operators to tackle more complex occlusions. Dissection/re-entry techniques (both antegrade and retrograde) are commonly used in angiographic scenarios characterised by long, tortuous and calcified occlusions, as well as in those with proximal cap ambiguity. Familiarity and comfort using the extraplaque space (with either an antegrade or retrograde approach) have become fundamental to achieving safe and effective recanalisation of complex chronic total occlusions. This review provides an overview of different contemporary antegrade and retrograde dissection re-entry techniques and their acute and longer-term outcomes.

Platinum chromium everolimus-eluting stents for the treatment of (complex) coronary artery disease; from SYNERGY™ to the MEGATRON™

INTRODUCTION

The introduction of drug-eluting coronary stents (DES) into clinical practice in 2002 represented a major milestone in the treatment of obstructive coronary artery disease. Over the years, significant advances in polymer coating and in antiproliferative agent technology have further improved the safety and clinical performance of newer-generation DES.

AREAS COVERED

Development of platinum chromium (PtCr) alloys with high radial strength and high radiopacity have enabled the design of new, thin-strut, flexible, and highly trackable stent platforms, while simultaneously improving stent visibility. These advances have facilitated complex percutaneous treatment of a diverse population of patients in clinical practice. This review will provide an overview of the evolution in PtCr everolimus-eluting stents from PROMUS Element™ to SYNERGY™ to the recently introduced SYNERGY MEGATRON™. The clinical data will be summarized and put into perspective, especially focusing on the role of the SYNERGY™ and MEGATRON™ platforms in the treatment of complex coronary artery disease and high-risk patients.

EXPERT OPINION

The SYNERGY™ stent demonstrates favorable clinical efficacy and safety outcome data, and whilst the clinical data on MEGATRON™ are sparse, early experience is promising. The specific overexpansion capabilities, visibility, and radial strength of the MEGATRON™ are attractive features for complex coronary interventions.

Procedural Results and Long-term Outcome of Chronic Total Occlusion Percutaneous Coronary Intervention in a UK Non-surgical Centre

Background

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has evolved a great deal over recent years, with increased procedural success and lower complication rates being reported. This study aims to evaluate the feasibility, safety and success of a dedicated CTO programme in a large UK PCI centre without on-site cardiothoracic surgery facilities.

Methods

Clinical and procedural data were retrospectively collected for consecutive unselected patients undergoing CTO PCI between 2015 and 2019 from the local database and regional electronic patient records. In-hospital outcomes and long-term major adverse cardiovascular events (all-cause mortality, MI, stroke and target vessel revascularisation) were recorded.

Results

A total of 170 patients underwent 191 CTO procedures during the study period. The mean age was 63 ± 10 years and 80.6% of patients were male (n=137). The clinical indications were: stable chronic coronary syndromes in 88.5% (n=169) of patients; staged procedures in the context of acute coronary syndromes in 1.6% (n=3); and presentation with acute coronary syndrome in 9.9% (n=19). The procedural success rate was 50.0% (n=25) for general interventional cardiologists and 90.1% (n=127) for dedicated CTO operators. In-hospital major adverse cardiovascular events occurred once (0.5%) and interhospital transfer for emergency salvage cardiac surgery was not required. Long-term follow-up data at a median duration of 3.8 years revealed 4 (2.4%) cardiac deaths, 14 (8.3%) spontaneous MI events and 10 (5.9%) target vessel revascularisations.

Conclusion

These data suggest CTO PCI using contemporary techniques is both safe and effective when undertaken in a high-volume non-surgical centre by experienced operators.

Computed Tomography Angiography-Derived Scores for Prediction of Chronic Total Occlusion Percutaneous Coronary Intervention Using the Hybrid Algorithm

Whereas coronary computed tomography angiography (CCTA) exceeds invasive angiography for predicting the procedural outcome of chronic total occlusion (CTO) percutaneous coronary intervention (PCI), CCTA-derived scores have never been validated in the hybrid CTO PCI population. In this single-center, retrospective, observational study, we included 108 consecutive patients with 110 CTO lesions and preprocedural CCTA who underwent hybrid CTO PCI to assess the diagnostic accuracy of CCTA-derived scoring systems. Successful guidewire crossing within 30 min was set as the primary endpoint. The secondary endpoints were final procedural success and the need for using any non-antegrade wiring (AW) strategy within the hybrid algorithm. Time-efficient guidewire crossing and final procedural success were achieved in 53.6% and 89.1% of lesions, respectively, while in 36.4% of the procedures, any non-AW strategy was applied. The median J-CTO score was 1 (interquartile range (IQR): 0, 2), while the CT-RECTOR, KCCT, J-CTOCCTA, and RECHARGECCTA scores were 2 (IQR: 1, 3), 3 (IQR: 2, 5), 1 (IQR: 0, 3), and 2 (IQR: 1, 3), respectively. All scores were significantly higher in the lesions with failed versus successful time-efficient guidewire crossing. Although all of the CCTA-derived scores had numerically higher predictive values than the angiographic J-CTO score, no significant differences were noted between the scores in any of the analyzed study endpoints. High sensitivity of the CT-RECTOR and RECHARGECCTA scores (both 89.8%) for predicting successful guidewire crossing within 30 min, and high sensitivity (90.8%) of the KCCT score for predicting final procedural success, were noted. CCTA-derived scoring systems are accurate, noninvasive tools for the prediction of the procedural outcome of hybrid CTO PCI, and may aid in identifying the need for use of the hybrid algorithm.

The role of intravascular imaging in chronic total occlusion percutaneous coronary intervention

Chronic total occlusions (CTOs) represent the most complex subset of coronary artery disease and therefore careful planning of CTO percutaneous coronary recanalization (PCI) strategy is of paramount importance aiming to achieve procedural success, and improve patient's safety and post CTO PCI outcomes. Intravascular imaging has an essential role in facilitating CTO PCΙ. First, intravascular ultrasound (IVUS), due to its higher penetration depth compared to optical coherence tomography (OCT), and the additional capacity of real-time imaging without need for contrast injection is considered the preferred imaging modality for CTO PCI. Secondly, IVUS can be used to resolve proximal cap ambiguity, facilitate wire re-entry when dissection and re-entry strategies are applied and most importantly to guide stent deployment and optimization post implantation. The role of OCT during CTO PCI is currently limited to stent sizing and optimization, however, due to its high spatial resolution, OCT is ideal for detecting stent edge dissections and strut malapposition. In this review, we describe the use of intravascular imaging for lesion crossing, plaque characterization and wire tracking, extra- or intra-plaque, and stent sizing and optimization during CTO PCI and summarize the findings of the major studies in this field.

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.

Computed tomography perfusion and angiography in patients with chronic total occlusion undergoing percutaneous coronary intervention

BACKGROUND AND AIMS

Myocardial perfusion imaging (MPI) and anatomical imaging with coronary computed tomography angiography (CCTA) can play an important role in the preprocedural planning of a chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We aimed to establish the feasibility of a novel dynamic computed tomography perfusion (CTP) analysis for the assessment of myocardial perfusion before and after a successful recanalization of CTO in patients undergoing CCTA as part of a standard preprocedural workup.

METHODS

In a prospective observational study symptomatic patients underwent dynamic CTP on a dual-source CT scanner both before and 3 months after successful CTO PCI.

RESULTS

Twenty-seven patients completed the study (63 ± 8 years old, 78% male). Following successful CTO PCI, there was a significant reduction in the ischemic burden (5 [5-7] versus 1 [0-2] segments, p < 0.001), and improvement in myocardial blood flow (85.3 [71.7-94.1] versus 134.6 [123.8-156.9] mL/min, p < 0.001) resulting in an increase in the relative flow reserve (0.49 [0.41-0.57] versus 0.88 [0.74-0.95], p < 0.001).

CONCLUSIONS

CTP emerges as a robust and safe method for MPI in CTO patients. The single imaging session assessment of both coronary anatomy and perfusion with CT lends itself to precise disease phenotyping in the challenging population of CTO patients.

Changes in absolute flow, myocardial resistance and FFR after chronic total occlusion percutaneous coronary intervention

BACKGROUND

Randomised studies of percutaneous coronary intervention (PCI) in patients with chronic total occlusion (CTO) have shown inconsistent outcomes, suggesting incomplete understanding of this cohort and their coronary physiology. To address this shortcoming, we designed a prospective observational study to measure the recovery of absolute coronary blood flow following successful CTO PCI Aims: We sought to identify patient and procedural characteristics associated with a favourable physiological outcome after CTO PCI.

METHODS

Consecutive patients with a CTO subtending viable myocardium underwent PCI utilising contemporary techniques and the hybrid algorithm. Immediately after PCI, and at 3-month follow-up, physiological measurements were performed utilising continuous thermodilution.

RESULTS

A total of 81 patients were included with a mean age of 63.6±8.9 years, and 66 (81.5%) were male. Physiological measurements of absolute coronary blood flow in the CTO vessel increased by 30% (p<0.001) and microvascular resistance reduced by 16% (p<0.001) from immediately post-CTO PCI to follow-up assessment. Fractional flow reserve increased by 0.02 (p=0.015) in the same period. Prior coronary artery bypass graft (CABG) and a higher estimated glomerular filtration rate (eGFR) were associated with a larger change in absolute flow. An extraplaque strategy was associated with a smaller change in absolute flow.

CONCLUSIONS

Post-CTO PCI, there is a continued augmentation in absolute coronary blood flow and reduction in microvascular resistance from baseline to follow-up at 3 months. Prior CABG and a higher baseline eGFR were predictors of a larger change in absolute coronary flow, whilst an extraplaque final wire path strategy predicted a smaller change. Lastly, the patient characteristics and comorbidities had a larger influence than procedural factors on the observed change in absolute flow.

Percutaneous coronary intervention improves quality of life of patients with chronic total occlusion and low estimated glomerular filtration rate

Background

A low estimated glomerular filtration rate (eGFR <90 mL/min/1.73 m²) is widely recognized as a risk factor for major adverse cardiac events (MACE) after percutaneous coronary intervention (PCI) for chronic total occlusion (CTO). However, the impact of successful CTO-PCI on quality of life (QOL) of patients with low eGFR remains unknown.

Objectives

The aim of this prospective study was to assess the QOL of CTO patients with low eGFR after successful PCI.

Methods

Consecutive patients undergoing elective CTO-PCI were prospectively enrolled and subdivided into four groups: eGFR ≥90 mL/min/1.73 m² (n = 410), 90 > eGFR ≥ 60 mL/min/1.73 m² (n = 482), 60 > eGFR ≥ 30 mL/min/1.73 m² (n = 161), and eGFR <30 mL/min/1.73 m² (n = 23). The primary outcomes included QOL, as assessed with the European Quality of Life-5 Dimensions (EQ-5D) questionnaire, and symptoms, as assessed with the Rose Dyspnea Scale (RDS) and Seattle Angina Questionnaire (SAQ), at 1 month and 1 year after successful PCI.

Results

With the decline of eGFR, CTO patients were more likely to present with comorbidities of hypertension, diabetes, hyperuricemia, and previous stroke, in addition to lower hemoglobin levels and left ventricular ejection fraction (p < 0.05). Low eGFR was associated with greater incidences of in-hospital pericardiocentesis, major bleeding, acute renal failure, and subcutaneous hematoma, but not in-hospital MACE (p < 0.05). Symptoms of dyspnea and angina were alleviated in all CTO patients with eGFR ≥30 mL/min/1.73 m² at 1 month and 1 year after successful CTO-PCI, but only at 1 month for those with eGFR <30 mL/min/1.73 m² (p < 0.01). Importantly, QOL was markedly improved at 1 month and 1 year after successful PCI (p < 0.01), notably at a similar degree between patients with low eGFR and those with normal eGFR (p > 0.05).

Conclusion

Successful PCI effectively improved symptoms and QOL of CTO patients with low eGFR.

Postdischarge prognostic significance of periprocedural myocardial injury after percutaneous intervention of chronic total occlusion

BACKGROUND

The postdischarge prognostic implication of periprocedural myocardial injury in patients undergoing percutaneous coronary intervention (PCI) of a chronic total occlusion (CTO) remains scarcely studied.

AIMS

The aim of this study is to assess the prognostic value of periprocedural myocardial injury, defined by increased high-sensitive troponin T (hs-TnT) levels according to updated guidelines, after CTO PCI.

METHODS

Between September 2011 and April 2020, 726 patients undergoing CTO PCI at 2 Belgian referral centres were prospectively included and divided into 4 groups based on postprocedural hs-TnT levels (unelevated; ≥5 times the upper limit of normal (ULN); ≥35 times the ULN; ≥70 times the ULN). Postprocedural hs-TnT levels were subsequently related to patient and procedural characteristics, 1-year major adverse cardiac and cerebrovascular events (MACCE; excluding in-hospital MACCE) as well as 1-year mortality.

RESULTS

At 1 year follow-up (FU), elevated hs-TnT≥5 times and ≥35 times the ULN were associated with higher MACCE rates (p=0.001; p=0.007, respectively). In addition, they also resulted in a higher 1-year mortality rate (p=0.009;p=0.021, respectively). Patients with increased hs-TnT≥5 times the ULN (35% of patients) more frequently had signs of more advanced atherosclerotic disease (previous CABG p<0.001; stroke p≤0.001 and peripheral vascular disease p<0.001) and had higher procedural complexity (Japanese CTO Score p=<0.001, stent length>48 mm p<0.001, procedure time p<0.001). Antegrade wire escalation did not result in lower event rate of postdischarge MACCE compared with the other CTO crossing techniques combined (p=0.158).

CONCLUSION

Periprocedural myocardial injury was associated with a significantly higher rate of MACCE and all-cause mortality after 12 months of FU.

Benefits of successful percutaneous coronary intervention in chronic total occlusion patients with diabetes

BACKGROUND

Diabetes was commonly seen in chronic total occlusion (CTO) patients but data regarding the impact of successful percutaneous coronary intervention (PCI) on clinical outcome of CTO patients with diabetes was controversial. And importantly, no studies have compared quality of life (QOL) after CTO-PCI in patients with and without diabetes.

METHODS

Consecutive patients undergoing elective CTO-PCI were prospectively enrolled from Apr. 2018 to May 2021. Patients were subdivided into 2 groups: Diabetes and No Diabetes. Detailed baseline characteristics, assessment of symptoms and QOL, angiographic and procedural details, in-hospital complications, and 1 month and 1 year follow-up data were collected. These data were analyzed accordingly for risk predictors of clinical outcome in patients who have diabetes and received successful CTO-PCI.

RESULTS

A total of 1076 patients underwent CTO-PCI attempts. Diabetes was present in 374 (34.76%) patients, who had more hypertension, previous PCI and stroke. Regarding the coronary lesions, diabetic patients suffered more LCX lesion, multivessel disease, number of lesions per patient, blunt stump, calcification and higher J-CTO score (p < 0.05). In-hospital major adverse cardiac event (MACE) (4.13% vs. 5.35%; p = 0.362) was similar in the two groups. At 1 month and 1 year follow-up after successful CTO-PCI, the incidence of MACE and all-cause mortality were also similar in the two groups (p > 0.05). Number of lesions per patient was an independent risk factor of MACE and all-cause mortality (p < 0.001) 1 year after successful CTO-PCI. Symptom and QOL were markedly improved regardless of diabetes both at 1 month and 1 year follow-up, and importantly, patients with diabetes showed similar degrees of improvement to those without diabetes (P > 0.05).

CONCLUSIONS

Successful CTO-PCI could represent an effective strategy improving clinical outcome, symptoms and QOL in CTO patients with diabetes.

Changes in coronary collateral function after successful chronic total occlusion percutaneous coronary intervention

BACKGROUND

Contemporary chronic total occlusion (CTO) percutaneous coronary intervention (PCI) incorporates wire escalation and dissection/re-entry recanalisation strategies.

AIMS

The purpose of the study was to investigate changes in collateral function after CTO PCI and to identify whether the mode of successful recanalisation influences collateral function regression.

METHODS

Patients scheduled for elective CTO PCI with evidence of viability in the CTO territory by noninvasive imaging were included in this study. After successful CTO PCI, the aortic pressure (Pa) and distal coronary artery wedge pressure (Pw) during balloon occlusion were measured, both in a resting state and during infusion of intravenous adenosine, allowing the calculation of the pressure-derived collateral pressure index at rest and hyperaemia (CPIrest and the collateral fractional flow reserve [FFRcoll], respectively). Measurements were repeated 3 months later during angiographic follow-up.

RESULTS

Eighty-one patients had physiological measurements at baseline and follow-up. In the final cohort the mean age was 64 years and 82% were male. The mean maximal stent diameter and total stent length were 3.2±0.5 mm and 68±31 mm, respectively. Successful strategies were antegrade wiring (64.2%), antegrade dissection re-entry (8.6%), and retrograde dissection re-entry (27.1%). Between the index procedure and follow-up, wedge pressure decreased from 34±11 mmHg to 21±8.5 mmHg (p<0.01), respectively. FFRcoll changed from 0.34±0.11 to 0.19±0.09 (p<0.01) at follow-up and CPIrest from 0.40±0.14 to 0.17±0.09 (p<0.01). Absolute maximum collateral flow decreased from 55±32 ml/min directly after PCI to 38±24 ml/min (p<0.01). There was no relation between the recanalisation technique and changes in FFRcoll.

CONCLUSIONS

There was a significant reduction in collateral flow over time, independent of the recanalisation technique.

Why and How Should We Treat Chronic Total Occlusion? Evolution of State-of-the-Art Methods and Future Directions

Chronic total occlusions are considered the most complex coronary lesion in interventional cardiology. The absence of visible lumen on angiography obscures the vessel course and makes vessel wiring unlikely with conventional techniques. Often a source of severe ischemia, chronic occlusions are also markers of advanced atherosclerosis that brings other complex features including lesion length, bifurcations, calcification, adverse vessel remodelling, distal disease, and anatomic distortion from previous bypass grafting. Often advanced atherosclerosis is associated with patient characteristics like left ventricular dysfunction, previous coronary bypass surgery, or multivessel disease that increase procedural demands and hazards. To accommodate these challenges new techniques and dedicated technologies have been developed. When applied to appropriate patients, these advances have improved procedural success, safety, and outcomes. Our aim is to provide the general cardiologist with an overview of these advances that can serve as a basis for counselling patients considered for revascularization.

Extraplaque versus intraplaque tracking in chronic total occlusion percutaneous coronary intervention

OBJECTIVE

To compare the clinical outcomes after extraplaque (EP) versus intraplaque (IP) tracking in chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

BACKGROUND

The impact of modern dissection and reentry (DR) techniques on the long-term outcomes of CTO PCI remains controversial.

METHODS

We performed a systematic review and meta-analysis of studies that compared EP versus IP tracking in CTO PCI. Odds ratios (ORs) with 95% confidence intervals (CIs) are calculated using the Der-Simonian and Laird random-effects method.

RESULTS

Our meta-analysis included seven observational studies with 2982 patients. Patients who underwent EP tracking had significantly more complex CTOs with higher J-CTO score, longer lesion length, and more severe calcification and had significantly longer stented segments. During a median follow-up of 12 months (range 9-12 months), EP tracking was associated with a higher risk of major adverse cardiovascular events (MACE) (OR 1.50, 95% CI (1.10-2.06), p = 0.01) and target vessel revascularization (TVR) (OR 1.69, 95% CI (1.15-2.48), p = 0.01) compared with IP tracking. There was no difference in the incidence of all-cause death (OR 1.37, 95% CI (0.67-2.78), p = 0.39), myocardial infarction (MI) (OR 1.48, 95% CI (0.82-2.69), p = 0.20), stent thrombosis (OR 2.09, 95% CI (0.69-6.33), p = 0.19), or cardiac death (OR 1.10, 95% CI (0.39-3.15), p = 0.85) between IP and EP tracking.

CONCLUSION

EP tracking is utilized in more complex CTOs and requires more stents. EP tracking is associated with a higher risk of MACE, driven by a higher risk of TVR at 1 year, but without an increased risk of death or MI compared with IP tracking. EP tracking is critically important for contemporary CTO PCI.

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.

Minimalistic hybrid approach for the percutaneous treatment of chronic coronary total occlusions: An in-depth analysis of the whole algorithm

INTRODUCTION

The minimalistic hybrid approach (MHA) is an algorithm to perform chronic total occlusion (CTO) percutaneous coronary intervention (PCI). The current study aims to evaluate the distribution of patients among the five different treatment strategies, the different techniques used in each strategy, the overall procedural success, and the safety of the MHA algorithm.

METHODS

Data from a consecutive series of patients with a CTO who underwent elective PCI between February 2019 and July 2021 were prospectively collected and retrospectively analyzed.

RESULTS

One hundred and forty-three CTOPCI in 135 patients were approached according to the MHA algorithm: 134 CTO (93.7%) were successfully recanalized and 9 procedures failed. About half of the procedures (48.3%) were approached using strategy A: antegrade "blind wiring" with contralateral retrograde options, making this the most popular strategy. A total of 89 procedures (62.2%) were completed with a single guiding catheter; in 86 (96.6%) a forearm approach was used. The remaining 54 cases were performed with dual access; in the majority of these patients (90.7%), a bilateral forearm approach was used. The only reason to use the femoral access was inadequate forearm access. One hundred and fifty-four out of 197 (78.2%) access sites were 6 French sheaths.

CONCLUSION

MHA is a stepwise approach focused on the forearm approach to reduce the number of access sites and catheter size used in CTOPCI while maintaining proficiency and safety. Operators should be warned that this approach should be adopted only by experienced CTO operators who master all the strategies of the classic hybrid algorithm and the forearm approach.

Contemporary Issues in Chronic Total Occlusion Percutaneous Coronary Intervention

Remarkable progress has been achieved in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in recent years, with refinement of the indications and technical aspects of the procedure, imaging, and complication management. Randomized controlled trials and rigorous prospective registries have provided high-quality data on the benefits and risks of CTO PCI. Global collaboration has led to an agreement on nomenclature, indications, endpoint definition, and principles of clinical trial design that have been distilled in global consensus documents such as the CTO Academic Research Consortium. Increased use of preprocedural coronary computed tomography angiography and intraprocedural intravascular imaging, as well as development of novel techniques and structured CTO crossing and complication management algorithms, allow a systematic, stepwise approach to this difficult lesion subset. This state-of-the-art review provides a comprehensive discussion about the most recent developments in the indications, preprocedural planning, technical aspects, complication management, and future directions of CTO PCI.

Update on chronic total occlusion percutaneous coronary intervention

Chronic total occlusion (CTO) percutaneous coronary interventions (PCI) can be challenging to perform. The main indication for CTO PCI is to improve symptoms. Several contemporary studies have reported high CTO PCI success rates at experienced centers but success rates in all-comer registries remain low. Several scores can estimate the difficulty and the likelihood of success of CTO PCI. Dual arterial access and use of CTO crossing algorithms can improve the success and safety of CTO PCI. Intracoronary imaging can optimize stent expansion and minimize adverse cardiovascular events. While complications are more common in CTO PCI, careful planning and prompt diagnosis and treatment can prevent them or minimize their adverse consequences. In this article, we review contemporary data on the indications, safety and efficacy of CTO PCI.

Clinical and angiographic outcomes of crossing techniques for coronary chronic total occlusions: the ISAR-CTO registry

BACKGROUND

Clinical and angiographic outcomes following recanalisation of coronary chronic total occlusions (CTO) through contemporary dissection and re-entry techniques (DART) as opposed to intraplaque techniques remain controversial.

AIMS

The aim of this study was to compare clinical and angiographic outcomes following subintimal and intraplaque CTO recanalisation.

METHODS

A total of 454 consecutive patients undergoing successful CTO recanalisation (473 vessels) were included. Intraplaque techniques were used in 403 (85.2%) and DART in 70 (14.8%) vessels. Surveillance angiography was scheduled at 6-9 months and clinical follow-up was performed up to 12 months.

RESULTS

There were no significant differences in terms of the cumulative incidence of MACE (p=0.908) or binary restenosis (p=0.320) between the two groups. There was no independent correlation between recanalisation technique and MACE occurrence or in-segment binary restenosis. Target lesion revascularisation (TLR) was performed in 60 (17.5%) and 12 (18.1%) (p=0.719) lesions, respectively. The occurrence of occlusive restenosis was low (7 [2.3%] vs 1 [1.6%]; p=0.824) and comparable between groups.

CONCLUSIONS

Contemporary DART are associated with similar midterm clinical and angiographic outcomes compared to intraplaque recanalisation. The rate of occlusive restenosis was low and comparable in both groups. Regardless of recanalisation technique, the overall incidences of binary restenosis and TLR following CTO recanalisation remain higher than those reported for non-CTO PCI.

Association of stent diameter and target vessel revascularization in patients undergoing percutaneous coronary intervention: a secondary retrospective analysis based on a Chinese cohort study

Background

In the treatment of coronary heart disease, target vessel revascularization (TVR) has attracted increasing attention as an efficient means of percutaneous coronary intervention (PCI). The purpose of this study was to explore the association between stent diameter and TVR in patients undergoing PCI.

Methods

This was a secondary retrospective analysis involving patients with PCI with at least one stent implanted. Information was obtained from the Dryad Digital Repository. Multivariable logistic regression models, interaction analyses, subgroup analyses and piecewise linear regression models were used to evaluate the association between stent diameter and TVR.

Results

A total of 2522 patients were eventually enrolled in this study, of which 122 (4.8%) had undergone TVR. Significant positive associations were observed between stent diameter and TVR (continuous: odds ratio [OR] 0.485, 95% confidence interval [CI] 0.305–0.773, P = 0.002; categorical variable: T2 vs. T1, OR 0.541, 95% CI 0.348–0.843; T3 vs. T1, OR 0.520, 95% CI 0.334–0.809; P for trend = 0.005). The association remained stable in the fully adjusted model (continuous: OR 0.526, 95% CI 0.306–0.902, P = 0.020; categorical variable: T2 vs. T1, OR 0.510, 95% CI 0.310–0.839; T3 vs. T1, OR 0.585, 95% CI 0.352–0.973; P for trend = 0.042). Among the subgroups of differing clinical presentations, stent diameter was a powerful protective factor for TVR, especially in the delayed PCI group (P for interaction = 0.002). The association was highly consistent across all the other subgroups studied (all P for interaction > 0.05). In the piecewise linear regression model, the need for TVR decreased with an increase in stent diameter when this ranged between 2.5 and 2.9 mm (OR 0.01, 95% CI: 0.01–0.13, P < 0.001).

Conclusions

A large stent diameter is a powerful protective factor for TVR in PCI patients, especially in the delayed PCI group. This “bigger-is-better” protective effect is remarkable in stents with diameter 2.5–2.9 mm.

[Technical armamentarium for chronic total occlusion of coronary vessels]

Percutaneous revascularization of chronic total occlusion (CTO) of coronary vessels represents a major challenge for contemporary interventional cardiologists. In the last decade there has been an unprecedented effort towards the standardization of revascularization procedures for CTO of coronary vessels. This endeavour has been possible by virtue of the growing interest of various cardiological societies for this patient group. Along with supportive endovascular technologies and percutaneous devices specifically dedicated to this interventional target, the increasing experience of interventionalists enabled continuously growing success for revascularization of CTO of coronary vessels. This review article highlights the currently available tools as well as technologies, techniques and strategies for the percutaneous recanalization of CTO of coronary vessels.

Subintimal shift at the bifurcation: A cause of side branch occlusion in chronic total occlusion intervention

Bifurcation lesions are frequently found in chronic total occlusion (CTO) percutaneous coronary intervention and are associated with lower procedural success and higher rates of complications, including side branch loss. In this report, we describe a poorly understood mechanism for side branch loss in CTO PCI: subintimal shift. This involves the extension of a dissection plane caused by subintimal (extraplaque) crossing in the main branch at the level of the side branch ostium, causing exclusion of the latter upon vessel preparation or stent placement. Subintimal shift (as compared to carina shift in non-CTO bifurcation intervention) appears to be under-recognized, and CTO operators should be aware that, from a technical standpoint, ballooning of the side branch is unlikely to restore and maintain flow, and a two-stent strategy is indicated to preserve the bifurcation.

Factors Influencing Stent Failure in Chronic Total Occlusion Coronary Intervention

Stent failure remains one of the greatest challenges for interventional cardiologists. Despite the evolution to superior second- and third-generation drug-eluting stent designs, increasing use of intracoronary imaging and the adoption of more potent antiplatelet regimens, registries continue to demonstrate a prevalence of stent failure or target lesion revascularisation of 15-20%. Predisposition to stent failure is consistent across both chronic total occlusion (CTO) and non-CTO populations and includes patient-, lesion- and procedure-related factors. However, histological and pathophysiological properties specific to CTOs, alongside complex strategies to treat these lesions, may potentially render percutaneous coronary interventions in this cohort more vulnerable to failure. Prevention requires recognition and mitigation of the precipitants of stent failure, optimisation of interventional techniques, including image-guided precision percutaneous coronary intervention, and aggressive modification of a patient's cardiovascular risk factors. Management of stent failure in the CTO population is technically challenging and itself begets recurrence. We aim to provide a comprehensive review of factors influencing stent failure in the CTO population and strategies to attenuate these.

Chronic total occlusion percutaneous coronary intervention in everyday clinical practice - an expert opinion of the Association of Cardiovascular Interventions of the Polish Cardiac Society

Coronary chronic total occlusions (CTO) are increasingly encountered during invasive and non-invasive coronary angiography and remain the most challenging lesions for percutaneous revascularization. During recent years success rates and safety outcomes of CTO percutaneous coronary intervention (PCI) have substantially improved, particularly due to the introduction of new techniques and dedicated equipment as well as specialized training programs of CTO operators. Significantly, the steady advances in CTO PCI techniques have coincided with the new data from randomized clinical trials supporting the role of percutaneous recanalization of CTO in relieving angina and improving the quality of life. The current expert consensus document outlines the rationale, clinical outcomes as well as technical, safety and reimbursement issues of CTO PCI. In addition, the requirements for achieving and maintaining competency in CTO PCI among interventional cardiologists are discussed. Finally, we present the modified hybrid algorithm (the so-called Polish hybrid algorithm) providing some unique refinements to the contemporary CTO PCI strategies. Continuous efforts (including active engagement with the payer) are urgently needed to increase guideline-recommended referrals to CTO PCI, and thus improve the quality of life of CTO patients in Poland.

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.

Technical Feasibility and Safety of Percutaneous Coronary Intervention for True Ostial Left Anterior Descending Artery-Chronic Total Occlusion

BACKGROUND

Percutaneous coronary intervention (PCI) for true ostial left anterior descending artery (LAD)-chronic total occlusion (CTO) lesions poses technical challenges owing to its inherent anatomic features.

METHODS

In total, 270 consecutive patients who underwent PCI for ostial LAD-CTO at 13 major cardiac centers in South Korea were included. Ostial LAD-CTO was strictly defined as a LAD-CTO lesion whose proximal cap was within 1 mm from the carina of the distal left main coronary artery (LMCA) bifurcation.

RESULTS

Ostial LAD-CTOs were frequently accompanied by stumpless lesion entry (43.4%), whereas significant bending within the occluded segment was less frequent (14.4%). The overall technical success rate was 85.9%, and serious in-hospital adverse events occurred in 5.6%. The retrograde approach tended to contribute more frequently to success in patients with concomitant LMCA disease, stumpless CTO, interventional collaterals, and higher Japanese-CTO scores. Apparent dissection or hematoma requiring rescue procedure at the LMCA or left circumflex artery occurred in 14 patients (5.2%), with a higher tendency in patients who had LMCA disease (12.1% vs 4.2%) and stumpless entry (9.4% vs 2.0%) than in those without. Among patients who were successfully treated, with an average of 1.7 stents, target-vessel failure occurred in 23 patients (9.9%) during a median 3.3 years of follow-up.

CONCLUSIONS

In this first large-scale analysis of true ostial LAD-CTO, PCI was feasible with a high technical success rate and favourable mid-term outcomes. Clinically relevant inflow vessel injury can occur during PCI and should be an important technical consideration regarding safety.

Antegrade Chronic Total Occlusion Strategies: A Technical Focus for 2020

Chronic total occlusions (CTOs) are common in patients with ischaemic heart disease. In many countries, patients with CTOs are underserved by percutaneous coronary intervention (PCI). One of the barriers to CTO PCI is the technical challenges of these procedures. Improvements in technique and dedicated devices for CTO PCI, combined with advances in procedural strategy, have resulted in a dramatic increase in procedural success and outcomes. Antegrade wiring (AW) is the preferred initial strategy in short CTOs, where the proximal cap and course of the vessel is understood. For many longer, more complex occlusions, AW has a low probability of success. Dissection and re-entry techniques allow longer CTOs and those with ambiguous anatomy to be crossed safely and efficiently, and CTO operators must also be familiar with these strategies. The CrossBoss and Stingray system is currently the primary targeted re-entry device used during antegrade dissection and re-entry (ADR), and there continues to be an evolution in its use to increase procedural efficiency. In contrast to older ADR techniques, targeted re-entry allows preservation of important side-branches, and there is no difference in outcomes compared to intraplaque stenting.