The Hybrid Approach to Chronic Total Occlusion Percutaneous Coronary Intervention

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

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

Predicting Successful Chronic Total Occlusion Crossing With Primary Antegrade Wiring Using Machine Learning

BACKGROUND

There is limited data on predicting successful chronic total occlusion crossing using primary antegrade wiring (AW).

OBJECTIVES

The aim of this study was to develop and validate a machine learning (ML) prognostic model for successful chronic total occlusion crossing using primary AW.

METHODS

We used data from 12,136 primary AW cases performed between 2012 and 2023 at 48 centers in the PROGRESS CTO registry (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention; NCT02061436) to develop 5 ML models. Hyperparameter tuning was performed for the model with the best performance, and the SHAP (SHapley Additive exPlanations) explainer was implemented to estimate feature importance.

RESULTS

Primary AW was successful in 6,965 cases (57.4%). Extreme gradient boosting was the best performing ML model with an average area under the receiver-operating characteristic curve of 0.775 (± 0.010). After hyperparameter tuning, the average area under the receiver-operating characteristic curve of the extreme gradient boosting model was 0.782 in the training set and 0.780 in the testing set. Among the factors examined, occlusion length had the most significant impact on predicting successful primary AW crossing followed by blunt/no stump, presence of interventional collaterals, vessel diameter, and proximal cap ambiguity. In contrast, aorto-ostial lesion location had the least impact on the outcome. A web-based application for predicting successful primary AW wiring crossing is available online (PROGRESS-CTO website) (https://www.progresscto.org/predict-aw-success).

CONCLUSIONS

We developed an ML model with 14 features and high predictive capacity for successful primary AW in chronic total occlusion percutaneous coronary intervention.

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 Bifurcation Involvement and Location in Chronic Total Occlusion Percutaneous Coronary Intervention: Insights From the EuroCTO Registry

Bifurcation involvement close to or within the occluded segment poses increasing difficulties for chronic total occlusion (CTO)-percutaneous coronary intervention (PCI). However, this variable is not considered in the angiography-based CTO scoring systems nor has been extensively investigated in large multicenter series. Accordingly, we analyzed a CTO-PCI registry involving 92 European centers to explore the incidence, angiographic and procedural characteristics, and outcomes specific to CTO-PCIs with bifurcation involvement. A total of 3,948 procedures performed between January and November 2023 were examined (33% with bifurcation involvement). Among bifurcation lesions, 38% and 37% were located within 5 mm of the proximal and distal cap, respectively, 16% within the CTO body, and in 9% of cases proximal and distal bifurcations coexisted. When compared with lesions without bifurcation involvement, CTO bifurcation lesions had higher complexity (J-CTO 2.33 ± 1.21 vs 2.11 ± 1.27, p <0.001) and were associated with higher use of additional devices (dual-lumen microcatheter in 27.6% vs 8.4%, p <0.001, and intravascular ultrasound in 32.2% vs 21.7%, p <0.001). Radiation dose (1,544 [836 to 2,819] vs 1,298.5 [699.1 to 2,386.6] mGy, p <0.001) and contrast volume (230 [160 to 300] vs 190 [130 to 250] ml, p <0.001) were also higher. Technical success was similar (91.5% with bifurcation involvement vs 90.4% without bifurcation involvement, p = 0.271). However, the bifurcation lesions within the CTO segment (intralesion) were associated with lower technical success than the other bifurcation-location subgroups (83.7% vs 93.3% proximal, 93.4% distal, and 89.0% proximal and distal, p <0.001). On multivariable analysis, the presence of an intralesion bifurcation was independently associated with technical failure (odds ratio 2.04, 95% confidence interval 1.24 to 3.35, p = 0.005). In conclusion, bifurcations are present in approximately one-third of CTOs who underwent PCI. PCI of CTOs with bifurcation can be achieved with high success rates except for bifurcations within the occluded segment, which were associated with higher technical failure.

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

Background

Chronic total occlusion (CTO) remains the most complex anatomical subset of lesions in percutaneous coronary intervention (PCI), often requiring advanced techniques and technologies, including the use of microcatheters.

Methods

The BIOMICS study is a premarket first-in-human prospective, multicenter, open-label, single-arm trial investigating the safety and efficacy of a novel coronary microcatheter (BioMC, Biosensors International) in 100 patients with symptoms of ischemia undergoing elective CTO-PCI. The primary efficacy end point of the study was device success defined according to the CTO-ARC (Chronic Total Occlusion Academic Research Consortium) criteria namely the ability of the microcatheter to successfully facilitate placement of a guide wire beyond the occluded coronary segment. The primary safety end point was the incidence of in-hospital cardiac death or myocardial infarction at hospital discharge.

Results

Hundred patients were recruited between March 2022 and January 2023. The primary efficacy end point was achieved in 75% of patients (95% CI, 65.3%-83.1%; P < .0001 for superiority compared to the prespecified performance goal of 54%). The primary safety end point of in-hospital cardiac death or myocardial infarction was observed in 2% of the patients. There were no study device-related coronary perforations or device failures.

Conclusions

The use of a novel coronary microcatheter during CTO-PCI was associated with a high device success and an excellent safety profile.

Is it Worthy Enough to Revascularize Chronically Occluded Coronaries?

Chronic total occlusions (CTOs) represent the "final frontier" of coronary interventions with the lowest procedural success rates and the most common reason for incomplete revascularization and referral to coronary artery bypass graft surgery (CABG). CTO lesions are not an infrequent finding during coronary angiography. They are often responsible for enhancing the complexity of the coronary disease burden thereby affecting the final interventional decision in the process. Notwithstanding the modest technical success of CTO-PCI, most of the earlier observational data demonstrated a clear survival benefit free of major cardiovascular events (MACE) in patients undergoing successful CTO revascularization. However, data from recent randomized trials fail to uphold the same survival advantage albeit, showing some trend toward improvement in left ventricular function, quality of life indicators and freedom from fatal ventricular arrythmia. Various guidance statements propose a well-defined role for CTO intervention in specific situations provided criterions for patient selection, appreciable inducible ischemia, myocardial viability and cost-risk-benefit analysis are met.

Ionizing radiation exposure in complex percutaneous coronary intervention: Defining local diagnostic reference levels in the catheterization laboratory

INTRODUCTION AND OBJECTIVES

Concerns regarding the consequences of ionizing radiation (IR) have been increasing in the field of interventional cardiology (IC). There is little information on reported national and local radiation diagnostic reference levels (DRLs) in catheterization laboratories in Portugal. This study was designed to assess the IR dose exposure during complex percutaneous coronary intervention (PCI), and to set the respective DRLs and future achievable doses (ADs).

METHODS

This was a retrospective cohort study which took place between 2019 and 2020, including patients who underwent complex PCI. Complex PCI was defined as all procedures that encompass treatment of chronic total occlusions (CTO) or left main coronary artery. DRLs were defined as the 75th percentile of the distribution of the median values of air kerma area product (PKA) and cumulative air kerma (Ka,r). ADs were set at the 50th percentile of the study dose distribution. Multivariate analysis was performed using linear regression to identify predictors significantly associated with radiation dose (Ka,r).

RESULTS

A total of 242 patients were included in the analysis. Most patients underwent a CTO procedure (146, 60.3%). Patients were aged 67.9±11.2 years and mostly male (81.4%). DRLs were set in Ka,r (3012 mGy) and PKA (162 Gy cm2) for complex PCI. ADs were also set in Ka,r (1917 mGy) and PKA (101 Gy cm2). Independent predictors of Ka,r with a positive correlation were PKA (0.893, p<0.001), fluoroscopy time (0.520, p<0.001) and PCI time (0.521, p<0.001).

CONCLUSIONS

This study reports the results of IR in complex PCI. DRLs were set for IR dose exposure measured in Ka,r (3012 mGy) and PKA (162 Gy cm2). ADs, values to be achieved in future assessment, were set to Ka,r (1917 mGy) and PKA (101 Gy cm2).

Impact of successful antegrade and retrograde CTO PCI on short-term prognosis

BACKGROUND

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) carries risk of complications and should be attempted when the anticipated benefits exceed the potential risks. The primary indication for CTO-PCI is symptom improvement. However, the impact of CTO-PCI on angina and subsequent incidence of major adverse cardiovascular event (MACE) rate remains controversial. Our aim was to study the impact of technically successful elective CTO-PCI on the procedural success rate and short-term MACE. The current study was a prospective cohort study that included a total of 80 patients who were referred to our center (Ain Shams University Hospitals) for elective CTO-PCI and underwent technically successful CTO-PCI. Data were collected on patient arrival to our department, and then, the patients were observed during hospital admission to record any In-Hospital MACE. These patients were then followed up for 6 months to record improvement or worsening of their symptoms and to assess occurrence of any MACE including hospitalization and undergoing symptom-driven coronary angiography.

RESULTS

The mean age of our patients was 56 ± 9.6 years, and 73 patients (91%) were men. Sixty-two patients (77.5%) were done via an antegrade approach, and 18 patients (22.5%) were done via a retrograde approach with an overall procedural success rate of 91.25% (antegrade 93.5%, retrograde 83.3%). The overall mean procedure time was 102 min, the mean contrast volume used was 371 ml, and the mean cumulative air kerma dose was 7.2 Gy. The retrograde group required longer procedure times, larger volumes of contrast and higher exposure to radiation. The overall in-hospital MACE was 8.75%. Sixty-five patients in our study (81.25%) showed an improvement in the grade of their exertional dyspnea or angina within the 6-month follow-up period. Thirteen patients in our study (16.25%) needed re-hospitalization within a 6-month period after PCI. The overall target lesion revascularization rate at 6 months was 8.75%.

CONCLUSIONS

Technically successful CTO PCI in a well-equipped center with highly qualified CTO operators resulted in high procedural success rates and low incidence of short-term MACE.

The outcomes and complications of percutaneous interventions in chronic total coronary occlusion

BACKGROUND

The limited availability of complex coronary intervention facilities and qualified operators, due to the high cost associated with chronic total occlusion (CTO) percutaneous intervention (PCI) equipment and a shortage of necessary skills, has led to a scarcity of capable medical centers in Pakistan. This study seeks to examine the outcomes and potential complications associated with CTO PCI procedures conducted at the Cardiac Catheterization Laboratories of a prominent national institute in Pakistan, which handles a large volume of cases.

RESULTS

Three hundred and six patients were included in the study in the study period of six months. The mean age was 59.49 (± 9.16) years: 256 (83.66%) were male and 50 (16.34%) were female. CTO was successfully re-vascularized in 237 (77.5%) with a complication rate of 13.7%. Two hundred and ninety-eight (97.39%) patients underwent an antegrade approach, while RCA was the most common target vessel (47.71%). Diabetes was the only significant associated risk factor with CTO PCI failure (30.43% vs. 30.43%, P-value = 0.015).

CONCLUSION

We achieved an excellent procedural success rate with a low complication rate. CTO procedural failure is associated with a higher complication rate, and diabetes is among the risk factors that lead to higher procedural failure.

The active pulling technique to solve microcatheter-uncrossable lesions in retrograde chronic total occlusion percutaneous coronary intervention

BACKGROUND

It is not uncommon to encounter retrograde microcatheter-uncrossable lesions in retro-recanalization of Chronic Total Occlusion (CTO) cases, existing solutions were time-consuming or complicated to operate. Therefore, the present study aimed to propose and evaluate the feasibility, safety of a novel technique termed Active Pulling retrograde microcatheter crossing Technique (APT) during retrograde CTO percutaneous coronary intervention (PCI).

METHODS

We retrospectively collected retrograde CTO-PCI cases from February 2017 to April 2023, only cases with the retrograde wire successfully crossed the CTO lesion were analyzed. The baseline clinical characteristics, angiographic characteristics, procedural details, and in-hospital major adverse cardiac events (MACEs) were compared.

RESULTS

A total of 80 CTO cases were divided into the APT group and the non-APT group according to whether the APT was applied in the procedure. The APT group had a higher rate of device success than the non-APT group (100% vs. 85%, P = 0.013), with shorter duration (5.3 ± 3.8 vs. 18.6 ± 5.9 min, P < 0.001) and a smaller number of retrograde microcatheters were used (P < 0.001). In the APT group, the average air kerma radiation exposure was lower (2.7 ± 1.2 vs. 4.3 ± 1.7 Gy, P < 0.001), the fluoroscopy time (69.0 ± 15.0 vs. 88.1 ± 18.9 min, P < 0.001) and the procedure time (116.2 ± 22.2 vs. 131.6 ± 28.7 min, P = 0.009) was shorter than the non-APT group. The technical success rate of both groups reached 100% while the procedure success rate was higher in the APT group than the non-APT group (100% vs. 85%, P = 0.13).

CONCLUSIONS

The APT is an easy and safe technique that can greatly improve procedural efficiency without adding other instruments, and allows the retrograde microcatheter to quickly crossing the CTO body after successful retrograde wire externalization.

Clinical outcomes of percutaneous coronary intervention in chronic total occlusion in patients with type 2 diabetes mellitus

INTRODUCTION AND OBJECTIVES

Coronary chronic total occlusions (CTOs) are relatively common findings in patients with type 2 diabetes mellitus (T2DM). However, the indication for percutaneous coronary intervention (PCI) and its clinical benefit in these patients remain controversial.

METHODS

A single-center retrospective cohort study with prospectively collected outcomes was carried out with CTO patients undergoing PCI in 2019 and 2020. Patients were divided into two groups according to previous T2DM diagnosis (T2DM and non-T2DM). The primary outcome was recurrence of angina and/or heart failure symptoms and secondary outcomes were myocardial infarction and all-cause mortality.

RESULTS

A total of 177 patients (82.5% male) were included in the analysis, with a mean age of 65±11 years. The primary outcome (total symptom recurrence) occurred in 16.6% of the sample, with no difference between groups (non-T2DM 13.6% vs. T2DM 21.2%, p=0.194) in a two-year follow-up. Angina recurrence was significantly more frequent in T2DM patients (15.2%, p=0.043). The presence of T2DM was not an independent predictor of symptom recurrence (p=0.429, HR 1.37, 95% CI 0.62-2.98). Myocardial infarction and all-cause mortality were also not different between groups (T2DM 1.5%, p=0.786 and 4.5%, p=0.352, respectively, on survival analysis). Independent predictors of all-cause mortality were left ventricular function and creatine clearance (p=0.039, HR 0.92, 95% CI 0.85-0.99 and p=0.013, HR 0.96, 95% CI 0.93-0.99, respectively).

CONCLUSIONS

T2DM did not influence outcomes in CTO patients undergoing PCI, and its presence should not be a limiting factor in deciding on CTO revascularization.

Clinical results of percutaneous coronary intervention in chronic total occlusions of the right coronary artery

INTRODUCTION AND OBJECTIVES

Coronary chronic total occlusions (CTOs) of the right coronary artery (RCA) are a relatively common finding in the context of coronary angiography. However, the benefit of revascularization remains controversial.

METHODS

A single-center retrospective cohort analysis prospectively collected outcomes of CTO patients undergoing percutaneous coronary intervention (PCI) in 2019 and 2020. Patients were divided into two groups according to the CTO vessel treated (left coronary artery [LCA]-CTO or RCA-CTO). The primary outcome was defined as the recurrence of angina and/or heart failure (HF) symptoms and secondary outcomes were myocardial infarction (MI) and all-cause mortality.

RESULTS

A total of 177 patients (82.5% male) were included in the analysis, with a mean age of 65±11 years. The primary outcome occurred in 28 (16.6%) patients and was significantly more frequent in RCA-CTO patients (19, 24.7%, p=0.010) in a mean follow-up of 18 months. This was mainly driven by recurrence of HF symptoms (12, 15.6%, p=0.013). Treated RCA-CTO was an independent predictor of the primary outcome (p=0.019, HR 2.66, 95% CI 1.17-6.05). MI and mortality rates were no different between groups (RCA-CTO with 1.3%, p=0.361 and 2.6%, p=0.673, respectively, on survival analysis). Left ventricular ejection fraction was an independent predictor of mortality (p=0.041, HR 0.93, 95% CI 0.87-0.99).

CONCLUSIONS

Revascularization of CTO lesions by PCI was associated with low rates of symptom recurrence, and clinical outcomes showed no differences regardless of which artery was treated. Recanalization of RCA-CTO was less beneficial in reducing the recurrence of HF symptoms.

Performance of the minimalistic hybrid approach algorithm versus other conventional algorithms in the percutaneous treatment of chronic total occlusions

BACKGROUND

The "Minimalistic Hybrid Approach" (MHA) has been proposed to reduce the invasiveness of chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

AIMS

This study aims to assess whether MHA may also reduce the utilization of PCI resources (devices, radiations, and contrast) by comparing it with other conventional algorithms.

METHODS

We aimed to assess the impact of MHA on device, radiation, and contrast usage during CTO-PCI analyzing data from the Belgian Working Group on CTO (BWG-CTO) registry. Patients were divided, depending on the algorithm used, into two groups: Conventional versus Minimalistic. Primary objectives were procedure performance measures such as device usage (microcatheters and guidewires), radiological parameters, and contrast use. At 1-year follow-up, patients were evaluated for target vessel failure (TVF), defined as a composite of cardiac death, new myocardial infarction, and target vessel revascularization.

RESULTS

Overall, we analyzed 821 CTO-PCIs (Conventional n = 650, Minimalistic n = 171). The Minimalistic group demonstrated higher complexity of CTO lesions. After adjusting for propensity score, the Minimalistic group had a significantly lower number of microcatheters used (1.49 ± 0.85 vs. 1.24 ± 0.64, p = 0.026), while the number of guidewires was comparable (4.80 ± 3.29 vs. 4.35 ± 2.94, p = 0.30). Both groups had similar rates of success and procedural complications, as well as comparable procedural and fluoroscopic times and contrast volume used. At the 1-year follow-up, both groups showed comparable rates of TVF (hazard ratio: 0.57; 95% confidence interval: 0.24-1.34, p = 0.195).

CONCLUSION

The MHA may slightly reduce the number of dedicated devices used during CTO-PCI, without adversely affecting the procedural success or long-term outcome.

A non-interventional cardiologist's guide to coronary chronic total occlusions

Coronary chronic total occlusions (CTO) are present in up to one-third of patients with coronary artery disease (CAD). It is thus essential for all clinical cardiologists to possess a basic awareness and understanding of CTOs, including optimal evaluation and management. While percutaneous coronary intervention (PCI) for CTO lesions has many similarities to non-CTO PCI, there are important considerations pertaining to pre-procedural evaluation, interventional techniques, procedural complications, and post-procedure management and follow-up unique to patients undergoing this highly specialized intervention. Distinct from other existing topical reviews, the current manuscript focuses on key knowledge relevant to non-interventional cardiologists.

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.

Coronary Physiology as Part of a State-of-the-Art Percutaneous Coronary Intervention Strategy: Lessons from SYNTAX II and Beyond

The use of coronary physiology allows for rational decision making at the time of PCI, contributing to better patient outcomes. Yet, coronary physiology is only one aspect of optimal revascularization. State-of-the-art PCI must also consider other important aspects such as intracoronary imaging guidance and specific procedural expertise, as tested in the SYNTAX II study. In this review, we highlight the technical aspects pertaining to the use of physiology as used in that trial and offer a glimpse into the future with emerging physiologic metrics, including functional coronary angiography, which have already established themselves as useful indices to guide decision making.

Prevalence of Collateral Typology in Coronary Chronic Total Occlusion and Its Impact on Percutaneous Intervention Performance

The presence of collateral channels providing distal blood supply is a distinctive characteristic of chronic total occlusion (CTO) lesions. However, data about the distinct baseline and procedural characteristics of each collateral subset are scarce. Accordingly, we sought to explore the procedural aspects specific for each collateral typology (ipsilateral collaterals [ICs], contralateral collaterals [CCs] or mixed) in CTO-percutaneous coronary intervention (PCI). A retrospective analysis of our CTO-PCI registry was performed to investigate the prevalence, procedural characteristics, and outcomes specific for each CTO-PCI subset, defined according to the inter-arterial connection anatomy. A total of 209 cases were included. Of the included cases, 45 (22%) and 92 (44%) patients displayed solely IC or CC, respectively, whereas in 72 (34%) both IC and CC were present (mixed). The procedural success rate was high (91.1%) and comparable among the different groups, despite greater lesion complexity in the CC group. The most frequent target vessel was the left circumflex in the IC group (51% of cases) and the right coronary artery in the CC (63%) and mixed (57%) groups. Among the IC cases, 42% showed a poor collateral connection function (2% and 10% for the CC and mixed group, respectively), and 46% showed a suboptimal collateral recipient artery filling (21% and 20% for the CC and mixed group, respectively). Most of the IC cases were performed using a single access (96%). In conclusion, the success and complication rates were comparable among the collateral typology groups, irrespective of the differences in the baseline and procedural characteristics. Phenotyping CTO as hereby proposed might be helpful for targeted procedural considerations.

Exploring indicators of success in chronic total occlusion percutaneous coronary intervention with Stingray system-based antegrade dissection re-entry: Insights from retrospective analysis

BACKGROUND

The predictors of success of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) through antegrade dissection and re-entry (ADR) using the Stingray system (Stingray ADR) remain elusive, mainly owing to the lack of consecutive angiographic and procedural records of patients.

OBJECTIVES

This study aimed to identify indicators that can determine the success of CTO PCI performed using the Stingray ADR technique.

METHODS

The clinical data of 115 patients who underwent CTO PCI through Stingray ADR at the same cardiac center were retrospectively and consecutively collected. Multivariate logistic regression analysis was performed to investigate the indicators of the success of ADR attempts.

RESULTS

The technical success rate of Stingray ADR in CTO PCI was 72.2%. The overall technical success rate of CTO recanalization was 78.3% in all CTO PCIs having used Stingray Low Profile balloon. Vessel calcification (odds ratio [OR]: 4.03; 95% confidence interval [CI]: 1.49-11.88; p = 0.008), and retrograde puncture indicator (OR: 4.89; 95% CI: 1.51-17.11; p = 0.009) were identified as independent positive predictors. Blunt/no stump proximal to the occlusion segment (OR: 0.22; 95% CI: 0.06-0.64; p = 0.009), decision time before Stingray ADR (per 1 h increase) (OR: 0.54; 95% CI: 0.31-0.92; p = 0.026), operation duration of Stingray ADR (per 10 min increase) (OR: 0.62; 95% CI: 0.40-0.94; p = 0.028), and puncture site at the intraplaque region (OR: 0.24; 95% CI: 0.06-0.84; p = 0.026) were identified as the four negative independent predictors.

CONCLUSIONS

This study revealed independent predictors of the success of CTO PCI performed using the Stingray ADR technique. As for CTO characteristics, the presence of calcification in the CTO segment and a tapered stump proximal to the lesion site can facilitate successful Stingray ADR. As for the procedures, the success rate of Stingray ADR can be improved by initiating the technique decisively and promptly, operating the system quickly and accurately and creating a puncture in the distal cap region of CTO under retrograde guidance.

Long-term clinical outcomes of drug-coated balloon for the management of chronic total occlusions

OBJECTIVES

This study aims to compare the clinical outcomes of patients with de novo chronic total occlusion (CTO) lesions treated by hybrid strategy and drug-coated balloons (DCB)-only strategy.

BACKGROUNDS

DCBs have been used as an alternative to or in combination with drug-eluting stents in CTO lesions. However, the clinical impact of DCB treatment on CTO lesion remains uncertain.

METHODS

We retrospectively enrolled 154 patients with de novo CTO lesions treated by DCB, including 57 cases in hybrid group and 97 cases in DCB-only group.

RESULTS

The lesions in hybrid group were more complicated than those in DCB-only group as shown by higher J-CTO score, and therefore higher percentage of retrograde approach, more IVUS guidance, more CTO guidewires, and longer procedural time were demonstrated. Although the percentage of non-flow-limiting dissection and residual stenosis of more than 30% were lower in hybrid group, TIMI flow grade, satisfactory and acceptable recanalization rate were not significantly different between two groups. During a median follow-up was 470 days, the incidence of target lesion revascularization (TLR), myocardial infarction and cardiac death was 11.0%, 1.3% and 1.9%, respectively. The long-term TLR-free survival was comparable between hybrid and DCB-only groups. By multivariate analysis, DCB length and age were predictors of TLR.

CONCLUSION

DCB treatment appears effective and safe in selected de novo CTO lesions during long-term follow up. The recanalization results and long-term outcomes are comparable between hybrid and DCB-only group despite more complicated lesions in hybrid group.

Early and long-term prognosis in patients with remaining chronic total occlusions after revascularization attempt. A cohort study from the SKEJ-CTO registry

OBJECTIVES

The present study aimed to compare safety and long-term prognosis of patients with chronic total coronary occlusions (CTO) stratified for remaining CTOs after percutaneous coronary intervention (PCI).

DESIGN

The study cohort consisted of patients with coronary artery disease who underwent CTO PCI in a high volume tertiary center from 2009 to 2019 and were registered in Danish high-quality registers. Patients with successful PCI of all CTOs were compared to patients with ≥1 remaining CTO post-procedural. Primary endpoints were analysed using Cox-regression and Kaplan-Meier estimates, and included all-cause mortality, major adverse cardio- and cerebrovascular events (MACCE) and a 30-day safety endpoint.

RESULTS

Procedural success rate was 87.7%, and 76.5% of patients had all CTO(s) opened post-PCI. Safety endpoint occurred in 4.6% of patients, and more frequently in patients with remaining CTO(s) (RD 4.9, 95%CI 0.1, 9.8). All-cause mortality was higher in patients with remaining CTO(s) (Unadjusted HR 1.65, 95% CI 1.03, 2.47, p = .015. Adjusted HR 1.32, 95%CI 0.88-1.99, p = .18) after eight years of follow-up. Risk of MACCE was significantly higher in patients with remaining CTO(s) (Unadjusted HR 1.79, 95% CI 1.34-2.41, p < .001. Adjusted HR 1.51, 95% CI 1.11-2.05, p = .009).

CONCLUSIONS

In our centre, CTO PCI was associated with high success rate and low risk of 30-days complications. Presence of remaining CTO(s) after final revascularization attempt was associated with higher but statistically insignificant long-term mortality but was an independent predictor of MACCE.

The Retrograde Approach to Chronic Total Occlusion Percutaneous Coronary Interventions: Technical Analysis and Procedural Outcomes

BACKGROUND

Retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is associated with lower success and higher complication rates when compared with the antegrade approach.

OBJECTIVES

This study sought to assess contemporary techniques and outcomes of retrograde CTO PCI.

METHODS

We examined the baseline characteristics, procedural techniques and outcomes of 4,058 retrograde CTO PCIs performed at 44 centers between 2012 and 2023. Major adverse cardiac events (MACE) included any of the following in-hospital events: death, myocardial infarction, repeat target vessel revascularization, pericardiocentesis, cardiac surgery, and stroke.

RESULTS

The average J-CTO (Multicenter CTO Registry in Japan) score was 3.1 ± 1.1. Retrograde crossing was successful in 60.5% and lesion crossing in 81.6% of cases. The collaterals pathways successfully used were septals in 62.0%, saphenous vein grafts in 17.4%, and epicardials in 19.1%. The technical and procedural success rates were 78.7% and 76.6%, respectively. When retrograde crossing failed, technical success was achieved in 50.3% of cases using the antegrade approach. In-hospital MACE was 3.5%. The clinical coronary perforation rate was 5.8%. The incidence of in-hospital MACE with retrograde true lumen crossing, just marker antegrade crossing, conventional reverse controlled antegrade and retrograde tracking (CART), contemporary reverse CART, extended reverse CART, guide-extension reverse CART, and CART was 2.1%, 0.8%, 5.5%, 3.0%, 2.1%, 3.2%, and 4.1%, respectively; P = 0.01).

CONCLUSIONS

Retrograde CTO PCI is utilized in highly complex cases and yields moderate success rates with 5.8% perforation and 3.5% periprocedural MACE rates. Among retrograde crossing strategies, retrograde true lumen puncture was the safest. There is need for improvement of the efficacy and safety of retrograde CTO PCI.

Outcomes of chronic total occlusion percutaneous coronary intervention from the RAIAN (RAjaie - Iran) registry

OBJECTIVE

While most of the evidence in CTO interventions emerge from Western and Japanese studies, few data have been published up today from the Middle East. Objective of this study was to evaluate technical success rates and clinical outcomes of an Iranian population undergoing CTO PCI in a tertiary referral hospital. Moreover, we sought to evaluate the efficacy of our CTO teaching program.

METHODS

This is a retrospective single-center cohort study including 790 patients who underwent CTO PCI performed by operators with different volumes of CTOs PCI performed per year. According to PCI result, all patients have been divided into successful (n = 555, 70.3 %) and unsuccessful (n = 235, 29.7 %) groups. Study endpoints were Major Adverse Cardiovascular Events and Health Status Improvement evaluated using the Seattle Angina Questionnaire at one year.

RESULTS

A global success rate of 70 % for antegrade and 80 % for retrograde approach was shown despite the lack of some CTO-dedicated devices. During the enrollment period, the success rate increased significantly among operators with a lower number of CTO procedures per year. One-year MACE rate was similar in both successful and unsuccessful groups (13.5 % in successful and 10.6 % in unsuccessful group, p = 0.173). One year patients' health status improved significantly only in successful group.

CONCLUSIONS

No significant differences of in-hospital and one-year MACE were found between the successful and unsuccessful groups. Angina symptoms and quality of life significantly improved after successful CTO PCI. The RAIAN registry confirmed the importance of operator expertise for CTO PCI success.

Contemporary In-Hospital Outcomes of Chronic Total Occlusion Percutaneous Coronary Interventions: Insights from the MENATA (Middle East, North Africa, Turkey, and Asia) Chapter of the PROGRESS-CTO Registry

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has been rapidly evolving in different parts of the world. We examined the clinical and angiographic characteristics and procedural outcomes of 1,079 consecutive CTO PCIs performed in 1,063 patients at 10 centers in the Middle East, North Africa, Turkey, and Asia regions between 2018 and 2022. The mean age was 61 ± 10 years and 82% of the patients were men. The prevalence of diabetes (49%) and previous PCI (50%) was high. The most common target vessel was the right coronary artery (51%), followed by the left anterior descending artery (33%) and the circumflex artery (15%). The mean Japanese CTO score was 2.1 ± 1.2 and mean PROGRESS-CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention) score was 1.2 ± 1.0. The technical and procedural success rates were high (91% and 90%, respectively) with a low incidence (1.6%) of in-hospital major adverse cardiac events. The incidence of perforation was 4.6% (n = 50): guidewire exit was the most common mechanism of perforation (48%) and 14 patients required pericardiocentesis (28%). Antegrade wire escalation was the most common crossing strategy used (91%), followed by retrograde approach (24%) and antegrade dissection and re-entry (12%). Median contrast volume, air kerma radiation dose, and fluoroscopy time were 300 (200 to 400) ml, 3.7 (2.0 to 6.3) Gy, and 40 (25 to 65) minutes, respectively. In conclusion, high success and acceptable complication rates are currently achieved at experienced centers in the Middle East, North Africa, Turkey, and Asia regions using a combination of crossing strategies.

Chronic Total Occlusion is Not a Risk Factor for Mortality in Patients With Successful Percutaneous Coronary Intervention: A Cohort Study

Background Fifteen percent of patients with coronary artery disease undergoing angiography have a chronic total occlusion (CTO). The current study aimed to investigate the long-term prognosis after successful and unsuccessful CTO percutaneous coronary intervention (PCI) compared with PCI for non-CTO lesions. Methods and Results The current study was designed as an observational, region-wide, register-based cohort study enrolling all patients undergoing PCI in the Central Region of Denmark in 2009 to 2019. Patients were stratified into non-CTO, successful CTO, and unsuccessful CTO revascularization. Patients were followed until an event or January 1, 2022. The primary end point was all-cause mortality. In 21 141 patients enrolled, 2108 underwent CTO PCI. Clinical presentation was acute coronary syndrome in 11 879 patients and chronic coronary syndrome in 7887 patients. After a median of 5.7 years (interquartile range, 3.3-8.8), long-term all-cause mortality was higher after CTO PCI compared with non-CTO PCI, but the difference was statistically insignificant when adjusting for clinical factors (unadjusted hazard ratio [HR], 1.19 [95% CI, 1.09-1.29], adjusted HR, 1.08 [95% CI, 0.97-1.20]; P=0.165). After successful CTO PCI, no difference compared with non-CTO PCI was observed (unadjusted HR, 0.99 [95% CI, 0.90-1.10], adjusted HR, 0.99 [95% CI, 0.87-1.12]; P=0.873). After unsuccessful CTO PCI, long-term all-cause mortality was higher than non-CTO PCI (unadjusted HR, 1.82 [95% CI, 1.59-2.08], adjusted HR, 1.35 [95% CI, 1.13-1.63]; P<0.001). Conclusions Patients undergoing PCI for CTO have elevated long-term mortality compared with patients without CTO. Successful opening of the CTO(s) is associated with equal mortality compared with non-CTO PCI. In contrast, failed CTO PCI is associated with worse long-term mortality. These findings suggest the need for CTO programs with high success rates and low complication rates.

Antegrade wire escalation in chronic total occlusions: State of the art review

Coronary chronic total occlusion percutaneous coronary intervention treatment algorithms have helped to standardize crossing strategy sequence to improve efficacy and efficiency of CTO interventions based on angiographic criteria. Unfortunately, advanced crossing techniques such as a retrograde and subintimal guidewire tracking and reentry that have accelerated procedural success in more difficult lesions are associated with higher major adverse cardiac event rates as compared with traditional antegrade and intimal guidewire tracking. In this regard, antegrade wire escalation (AWE) remains the most common CTO crossing strategy. In this state of the art review, we outline the techniques employed to maximize the clinical utility of AWE crossing strategy for both novice operators as well as those experienced with the advanced crossing strategies. For the less experienced operator, these techniques may provide a framework to treat more patients safely and effectively without the need to refer to a more advanced operator. Whereas these same techniques may be employed by an advanced operator to improve the technical success in procedures requiring more advanced crossing strategies.

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.

Antegrade versus Retrograde Approach for Recanalization of Ostial or Stumpless Coronary Chronic Total Occlusion

Purpose

This research aimed to evaluate the procedural and in-hospital clinical outcomes of percutaneous coronary intervention (PCI) for ostial or stumpless chronic total occlusion (CTO) utilizing both the antegrade-only and retrograde approaches.

Methods

A comprehensive retrospective examination was conducted on the procedural and in-hospital clinical outcomes of 89 consecutive patients subjected to ostial or stumpless CTO PCI at our institution between April 2015 and October 2022.

Results

The antegrade-only technique demonstrated a superior technical success rate (92.0% vs 71.9%, p = 0.041) and procedural success rate (92.0% vs 68.8%, p = 0.022) in comparison to the retrograde approach (RA). The RA group presented a notably elevated Japanese-CTO (J-CTO) score relative to the antegrade-only approach group (2.45±0.73 vs 1.64±0.70, p < 0.001). The antegrade-only approach group manifested an increased frequency of microchannels at the proximal stump relative to the RA group (56.0% vs 10.9%, p < 0.001). In-hospital major adverse cardiac events (MACE) and in-hospital myocardial infarction (MI) were observed more prevalently in the RA group (18.8% vs 0, p = 0.003; 15.6% vs 0, p = 0.008; respectively). A J-CTO score below 2 and the manifestation of microchannels at the proximal stump were identified as predictors for successful antegrade-only approach PCI for ostial or stumpless CTO (OR: 2.79 [95% CI: 1.92-5.03, P =0.003]; OR: 2.89 [95% CI: 1.32-6.03, P =0.001]; respectively).

Conclusion

Relative to RA PCI for ostial or stumpless CTO, the antegrade-only approach is utilized for less complex CTO lesions and is associated with a diminished probability of in-hospital MACE.

Effect of preoperative coronary CT for planning of percutaneous coronary intervention for complex chronic total occlusion (CTS-C-CTOPCI): study protocol for an open-label randomised controlled trial

BACKGROUND

Treatment of chronic total occlusion (CTO) by percutaneous coronary intervention (PCI) is associated with the difficulty of guidewire manipulation through the occluded segment, particularly when there is hard tissue due to calcification. The purpose of this randomised controlled trial is to determine whether improved planning of CTO-PCI using coronary computed tomographic angiography (CCTA) (versus conventional angiography) increases success rates of wire crossing in ≤ 60 min in difficult cases.

METHODS

This is a randomised controlled open-label multi-centre trial in a superiority framework with 1:1 allocation ratio. Participants (n = 130) will be randomised into two groups: the study group who will receive standard of care with the addition of preoperative coronary computed tomographic angiography (CT group), and the control group that will receive standard of care (angiography group). The primary endpoint will be the rate of successful wire crossing in ≤ 60 min in complex CTO (J-CTO ≥ 2). Wire crossing will be considered successful if TIMI flow 3 is restored and residual stenosis is < 30%. The safety endpoint will be mortality due to the intervention or major adverse cardiac events (MACE). Secondary endpoints are success rates at any time; total time of PCI; time of wire crossing; rate of PCI complications; radiation levels during PCI; volume of iodine contrast medium administered; and cost of the PCI.

DISCUSSION

This randomised trial will provide insight into whether pre-procedural CCTA as opposed to conventional angiography for planning of CTO-PCI yield higher success rates of wire crossing in ≤ 60 min. Potential benefits of CCTA include shorter successful procedure times of CTO-PCI leading to less irradiation and contrast medium with lower complication rates.

TRIAL REGISTRATION

Clinical Trials.gov NCT04549896. Registered on December 21, 2021.

Efficiency of the Guide Extension Catheter-Facilitated Tip-in Technique in the Recanalization of Coronary Chronic Total Occlusion

Background

The tip-in technique, which involves advancing an antegrade microcatheter cross the lesion over a retrograde guidewire, is an elaborated maneuver in the recanalization of coronary chronic total occlusion (CTO). We seek to assess the efficiency of a guide extension catheter-facilitated tip-in technique in comparison to the traditional retrograde approach, which is accomplished by an externalization wire.

Methods

Thirty-three CTO patients successfully revascularized using guide extension catheter-facilitated "tip-in" were included and matched with another 33 patients by J-CTO score and operators, whose CTO was recanalized using an externalized wire. The manipulation time from the first retrograde wire entering the antegrade guide to the first antegrade balloon inflation in the occlusion was calculated.

Results

Compared with the wire-externalization group, the manipulation time in the tip-in group was significantly shortened [389s; interquartile range (IQR), 272-478 vs 706s; IQR, 560-914; p < 0.001]. There was a trend in decreasing total operation time and radiation dose, but it did not reach statistical significance.

Conclusion

Guide extension catheter-facilitated tip-in is an efficient method to achieve the recanalization of CTO in a retrograde way, which would be pivotal when the retrograde microcatheter could not be advanced into the antegrade guide catheter.

Vascular Access in Percutaneous Coronary Intervention of Chronic Total Occlusions: A State-of-the-Art Review

The outcomes of chronic total occlusion percutaneous coronary intervention have considerably improved during the last decade with continued emphasis on improving procedural safety. Vascular access site bleeding remains one of the most frequent complications. Several procedural strategies have been implemented to reduce the rate of vascular access site complications. This state-of-the-art review summarizes and describes the current evidence on optimal vascular access strategies for chronic total occlusion percutaneous coronary intervention.

Complete Revascularization and Angina-Related Health Status in the ISCHEMIA Trial

BACKGROUND

The impact of complete revascularization (CR) on angina-related health status (symptoms, function, quality of life) in chronic coronary disease (CCD) has not been well studied.

OBJECTIVES

Among patients with CCD randomized to invasive (INV) vs conservative (CON) management in ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches), we compared the following: 1) the impact of anatomic and functional CR on health status compared with incomplete revascularization (ICR); and 2) the predicted impact of achieving CR in all INV patients compared with CON.

METHODS

Multivariable regression adjusting for patient characteristics was used to compare 12-month health status after independent core laboratory-defined CR vs ICR in INV patients who underwent revascularization. Propensity-weighted modeling was then performed to estimate the treatment effect had CR or ICR been achieved in all INV patients, compared with CON.

RESULTS

Anatomic and functional CR were achieved in 43.3% and 57.8% of 1,641 INV patients, respectively. Among revascularized patients, CR was associated with improved Seattle Angina Questionnaire Angina Frequency compared with ICR after adjustment for baseline differences. After modeling CR and ICR in all INV patients, patients with CR and ICR each had greater improvements in health status than CON, with better health status with CR than ICR. The projected benefits of CR were most pronounced in patients with baseline daily/weekly angina and not seen in those with no angina.

CONCLUSIONS

Among patients with CCD in ISCHEMIA, health status improved more with CR compared with ICR or CON, particularly in those with frequent angina. Anatomic and functional CR provided comparable improvements in quality of life. (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches [ISCHEMIA]; NCT01471522).

Impact of minimum contrast media volumes during percutaneous coronary intervention for chronic total occlusion lesion

Contrast media exposure is associated with contrast-induced nephropathy (CIN) following percutaneous coronary intervention (PCI) of chronic total occlusion (CTO). Aim of this study is to assess the utility of minimum contrast media volume (CMV ≤ 50 mL) during CTO-PCI for CIN prevention in patients with chronic kidney disease (CKD). We extracted data from the Japanese CTO-PCI expert registry; 2863 patients with CKD who underwent CTO-PCI performed from 2014 to 2020 were divided into two groups: minimum CMV (n = 191) and non-minimum CMV groups (n = 2672). CIN was defined as an increased serum creatinine level of ≥ 25% and/or ≥ 0.5 mg/dL compared with baseline levels within 72 h of the procedure. In the minimum CMV group, the CIN incidence was lower than that in the non-minimum CMV group (1.0% vs. 4.1%; p = 0.03). Patient success rate was higher and complication rate was lower in the minimum CMV group than in the non-minimum CMV group (96.8% vs. 90.3%; p = 0.02 and 3.1% vs. 7.1%; p = 0.03). In the minimum CMV group, the primary retrograde approach was more frequent in the case of J-CTO = 1,2 and 3-5 groups compared to that in non-minimum CMV-PCI group (J-CTO = 0; 11% vs. 17.7%, p = 0.06; J-CTO = 1; 22% vs. 35.8%, p = 0.01; J-CTO = 2; 32.4% vs. 46.5%, p = 0.01; and J-CTO = 3-5; 44.7% vs. 80.0%, p = 0.02). Minimum CMV-PCI for CTO in CKD patients could reduce the incidence of CIN. The primary retrograde approach was observed to a greater extent in the minimum CMV group, especially in cases of difficult CTO.

Percutaneous Coronary Intervention for Chronic Total Occlusion-Contemporary Approach and Future Directions

In the aging society, the issue of coronary chronic total occlusion (CTO) has become a challenge for invasive cardiologists. Despite the lack of clear indications in European and American guidelines, the rates of percutaneous coronary interventions (PCI) for CTO increased over the last years. Well-conducted randomized clinical trials (RCT) and large observational studies brought significant and substantial progress in many CTO blind spots. However, the results regarding the rationale behind revascularization and the long-term benefit of CTO are inconclusive. Knowing the uncertainties regarding PCI CTO, our work sought to sum up and provide a comprehensive review of the latest evidence on percutaneous recanalization of coronary artery chronic total occlusion.

Overview of Percutaneous Coronary Interventions for Chronic Total Occlusions Treated at Brazilian Centers Participating in the LATAM CTO Registry

BACKGROUND

Major advances have been seen in techniques and devices for performing percutaneous coronary interventions (PCIs) for chronic total occlusions (CTOs), but there are limited real-world practice data from developing countries.

OBJECTIVES

To report clinical and angiographic characteristics, procedural aspects, and clinical outcomes of CTO PCI performed at dedicated centers in Brazil.

METHODS

Included patients underwent CTO PCI at centers participating in the LATAM CTO Registry, a Latin American multicenter registry dedicated to prospective collection of these data. Inclusion criteria were procedures performed in Brazil, age 18 years or over, and presence of CTO with PCI attempt. CTO was defined as a 100% lesion in an epicardial coronary artery, known or estimated to have lasted at least 3 months.

RESULTS

Data on 1196 CTO PCIs were included. Procedures were performed primarily for angina control (85%) and/or treatment of moderate/severe ischemia (24%). Technical success rate was 84%, being achieved with antegrade wire approaches in 81% of procedures, antegrade dissection and re-entry in 9%, and retrograde approaches in 10%. In-hospital adverse cardiovascular events occurred in 2.3% of cases, with a mortality rate of 0.75%.

CONCLUSIONS

CTOs can be treated effectively in Brazil by using PCI, with low complication rates. The scientific and technological development observed in this area in the past decade is reflected in the clinical practice of dedicated Brazilian centers.

Contemporary Management Before Chronic Total Occlusion Percutaneous Coronary Interventions: Insights From the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program

BACKGROUND

Guidelines recommend maximal antianginal medical therapy before attempted coronary artery chronic total occlusion (CTO) percutaneous coronary intervention (PCI). The degree to which this occurs in contemporary practice is unknown. We aimed to characterize the frequency and variability of preprocedural use of antianginal therapy and stress testing within 3 months before PCI of CTO (CTO PCI) across a nationally integrated health care system.

METHODS

We identified patients who underwent attempted CTO PCI from January 2012 to September 2018 within the Veterans Affairs Healthcare System. Patients were categorized by management before CTO PCI: presence of ≥2 antianginals, stress testing, and ≥2 antianginals and stress testing within 3 months of PCI attempt. Multivariable logistic regression and inverse propensity weighting were used for adjustment before trimming, with median odds ratios calculated for variability estimates.

RESULTS

Among 4250 patients undergoing attempted CTO PCI, 40% received ≥2 antianginal medications and 24% underwent preprocedural stress testing. The odds of antianginal therapy with more than one medication before CTO PCI did not change over the years of the study (odds ratio [OR], 1.0 [95% CI, 0.97-1.04]), whereas the odds of undergoing preprocedural stress testing decreased (OR, 0.97 [95% CI, 0.93-0.99]), and the odds of antianginal therapy with ≥2 antianginals and stress testing did not change (OR, 0.98 [95% CI, 0.93-1.04]). Median odds ratios (MOR) showed substantial variability in antianginal therapy across hospital sites (MOR, 1.3 [95% CI, 1.26-1.42]) and operators (MOR, 1.35 [95% CI, 1.26-1.63]). Similarly, preprocedural stress testing varied significantly by site (MOR, 1.68 [95% CI, 1.58-1.81]) and operator (MOR, 1.80 [95% CI, 1.56-2.38]).

CONCLUSIONS

Just under half of patients received guideline-recommended management before CTO PCI, with significant site and operator variability. These findings suggest an opportunity to reduce variability in management before CTO PCI.

Role of the retrograde Carlino technique for chronic total occlusion percutaneous coronary intervention

BACKGROUND

There is scarce data on the outcomes of the Carlino technique for chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We aimed to investigate the indications and outcomes of the Carlino technique as performed in the context of the retrograde approach.

METHODS

We pooled CTO PCI cases where a retrograde Carlino technique was performed from high-volume operators at four centers. The Carlino technique was characterized according to its indication (achieving plaque/cap modification, clarifying microcatheter location within the vessel, resolving distal cap ambiguity) and was considered successful when it led to the desired outcome.

RESULTS

A total of 43 patients were included. Occlusion complexity was very high (mean J-CTO score 3.3 ± 0.8). The two most common indications were understanding the anatomy of the occlusion and clarifying gear location (37.2%) and impenetrable distal cap (34.9%). The Carlino technique was successful in 88.4% of cases. Overall technical and procedural success was 86.0%. The most common successful crossing technique was reverse controlled antegrade and retrograde subintimal tracking (70.3%). No complications were attributed to the Carlino technique.

CONCLUSIONS

We observed a high success rate of the retrograde Carlino technique, as well as overall technical and procedural success rates. No Carlino technique-related complications were observed. Additional data from larger registries are warranted to further confirm the safety and efficacy of this technique.

Coronary Physiology as Part of a State-of-the-Art Percutaneous Coronary Intervention Strategy: Lessons from SYNTAX II and Beyond

The use of coronary physiology allows for rational decision making at the time of PCI, contributing to better patient outcomes. Yet, coronary physiology is only one aspect of optimal revascularization. State-of-the-art PCI must also consider other important aspects such as intracoronary imaging guidance and specific procedural expertise, as tested in the SYNTAX II study. In this review, we highlight the technical aspects pertaining to the use of physiology as used in that trial and offer a glimpse into the future with emerging physiologic metrics, including functional coronary angiography, which have already established themselves as useful indices to guide decision making.

Patient Selection and Clinical Indication for Chronic Total Occlusion Revascularization-A Workflow Focusing on Non-Invasive Cardiac Imaging

Percutaneous coronary intervention of chronic total occlusion (CTO PCI) is a challenging procedure with high complication rates and, as not yet fully understood long-term clinical benefits. Ischemic symptom relief in patients with high ischemic burden is to date the only established clinical indication to undergo CTO PCI, supported by randomized controlled trials. In this context, current guidelines suggest attempting CTO PCI only in non-invasively assessed viable CTO correspondent myocardial territories, with large ischemic areas. Hence, besides a comprehensive coronary angiography lesion evaluation, the information derived from non-invasive cardiac imaging techniques is crucial to selecting candidates who may benefit from the revascularization of the occluded vessel. Currently, there are no clear recommendations for a non-invasive myocardial evaluation or choice of imaging modality pre-CTO PCI. Therefore, selecting among available options is left to the physician's discretion. As CTO PCI is strongly recommended to be carried out explicitly in experienced centers, full access to non-invasive imaging for risk-benefit assessment as well as a systematic institutional evaluation process has to be encouraged. In this framework, we opted to review the current myocardial imaging tools and their use for indicating a CTO PCI. Furthermore, based on our experience, we propose a cost-effective systematic approach for myocardial assessment to help guide clinical decision-making for patients presenting with chronic total occlusions.

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.

Access Site Selection and Outcomes for Chronic Total Occlusion Percutaneous Coronary Interventions: Insights from the VA CART Program

Background

There has been increasing use of transradial access (TRA) for non-chronic total occlusion (CTO) percutaneous coronary intervention (PCI). There are limited data on TRA for CTO PCI. The objectives of this study were to assess the temporal trends in the use of TRA versus transfemoral access (TFA), identify procedural and lesion characteristics associated with the use of TRA and TFA, and evaluate the association of access site with procedural complications and technical success among veterans undergoing attempted CTO PCI.

Methods

We performed a retrospective analysis of veteran patients who underwent attempted CTO PCI to compare outcomes between TRA and TFA. Patients who had undergone attempted PCI of at least 1 CTO were included. Propensity score matching was used to evaluate the composite primary outcome of major procedural complications, in-hospital bleeding, or 30-day mortality and the secondary outcome of procedural success.

Results

In total, 4609 patients underwent attempted CTO PCI during 2010-2017. Rates of TRA for CTO PCI increased significantly, from 7% in 2010 to 38% in 2017 (P trend < .01). A greater percentage of CTO lesions in the TFA group was calcified and >20.0 mm in length. TRA was not associated with a reduction in the composite primary outcome (TRA 3.3% vs TFA 4.0%, P = .47) or procedural success (TRA 66.6% vs TFA 65.7%, P = .74) compared with TFA.

Conclusions

In this retrospective analysis of patients who underwent attempted CTO PCI, the proportion of TRA for CTO PCI has increased over time but was not associated with a greater safety or procedural success than TFA.

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.

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.

Grade 3 coronary artery perforations in chronic total occlusion-percutaneous coronary intervention: Mechanisms, locations, and outcomes from the G3CAP Registry

AIM

The impact of Grade III coronary perforations (G3-CP) in the setting of CTO-PCI is not well assessed.

METHODS AND RESULTS

We reviewed 7773 CTO-PCI and 98,819 non CTO-PCI performed in 10 European centers: G3 perforation occurred in 87 patients (1.1%) during CTO PCI and 224 patients (0.22%) during non CTO-PCI (p < 0.001). G3-CP involved the CTO segment in 68% of patients and the retrograde channels in 14% of cases. In the CTO PCI group, wire induced G3-CP (50.5% vs. 32.5%, p = 0.02) occurred predominantly when dedicated CTO tapered and highly penetrative wires were used. Intra-procedural and in-hospital death rates were 4.6% vs. 5.8% and 3.6% vs. 7.5% respectively for CTO PCI and non-CTO PCI groups (p = NS). At a median follow up of 24 months, the overall mortality and MAE were respectively 7.8% and MAE 19% without difference among groups.

CONCLUSIONS

We showed similar in-hospital and long-term outcomes when G3 perforations occurred during CTO PCI and non CTO-PCI.

Safety and feasibility of transradial access for percutaneous coronary intervention in chronic total occlusions

INTRODUCTION AND OBJECTIVES

Transfemoral access is the most frequently used vascular approach in chronic total occlusion percutaneous coronary interventions (CTO-PCI). The aim of this study was to evaluate the safety and feasibility of a transradial access CTO-PCI program and its impact on angiographic and clinical results and length of hospital stay.

METHODS

Retrospective multicenter cohort study including 2550 consecutive CTO-PCI procedures included in a multicenter registry with accurate information on vascular access. A total of 896 procedures were performed as radial-only access while 1654 were performed through at least 1 femoral puncture. Clinical and angiographic data were collected.

RESULTS

The mean age was 66.3± 11.4 years. The mean Japan-chronic total occlusion score (2.7±0.3) was similar in the 2 groups. Successful revascularization was achieved in 2009 (79.6%) cases, 78.2% and 82.1% in the femoral and radial access cohorts, respectively (P=.002). Periprocedural in-hospital complications were observed in 5.1% and 2.3% (P=.02), with fewer access site-dependant vascular complications in the transradial cohort (2.3% vs 0.2%; P=.009). The mean length of hospital stay was significantly shorter in the transradial access group (0.89±1.4 vs 2.2±3.2 days, P<.001).

CONCLUSIONS

A transradial program for CTO-PCI is safe and effective in most CTO lesions. The transradial strategy has fewer vascular complications and shorter length of hospital stay without compromising the success rate.

Impact of Timing and Treatment Strategy on Coronary Perforation During Percutaneous Coronary Intervention for Chronic Total Occlusion

Coronary perforations during chronic total occlusion percutaneous coronary intervention (CTO-PCI) are potential complications and reportedly associated with adverse events. This study aimed to describe the clinical characteristics and timing of perforations during CTO-PCI. Data from the Japanese CTO-PCI expert registry included 8,760 patients who underwent CTO-PCI between January 2014 and January 2019. The major adverse cardiac and cerebrovascular events were defined as death, tamponade, myocardial infarction, stent thrombosis, stroke, and revascularization. The guidewire manipulation time was defined as the time required to cross the CTO without perforation. Among these patients, 333 (3.8%) developed perforation during the CTO crossing attempt. Of the 333 patients, 29 developed cardiac tamponades (8.7%). Perforations more frequently occurred in a retrograde wiring than in an anterograde wiring (6.6% vs 1.7%, p <0.0001). A longer guidewire manipulation time was associated with the occurrence of perforation (median 101 minutes [interquartile range 59 to 150 minutes] in the perforation group vs 54.9 minutes [interquartile range 21.1 to 112.7 minutes] in the nonperforation group, p <0.0001). Risk factors for perforation were age, history of coronary bypass graft, right coronary artery lesion, de novo lesion, use of a stiff guidewire, and guidewire manipulation time of >60 minutes during anterograde wiring and age, non-left anterior descending artery lesion, use of a polymer-jacketed guidewire, and use of epicardial channel during retrograde wiring. In conclusion, risk factors for perforation were different between anterograde and retrograde wirings. A prolonged guidewire manipulation time was associated with the occurrence of perforation, especially during anterograde wiring.

Femoral or Radial Approach in Treatment of Coronary Chronic Total Occlusion: A Randomized Clinical Trial

OBJECTIVES

The aim of this study was to compare transradial access (TRA) with transfemoral access (TFA) for chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

BACKGROUND

TRA reduces the risk for vascular access complications but may make complex PCI, such as CTO PCI, more challenging.

METHODS

FORT CTO (Femoral or Radial Approach in the Treatment of Coronary Chronic Total Occlusion) (NCT03265769) was a prospective, noninferiority, randomized controlled study of TRA vs TFA for CTO PCI. The primary study endpoint was procedural success, defined as technical success without any in-hospital major adverse cardiovascular events. The secondary study endpoint was major access-site complications.

RESULTS

Between 2017 and 2021, 610 of 800 patients referred for CTO PCI at 4 centers were randomized to TRA (n = 305) or TFA (n = 305). Mean J-CTO (Multicenter CTO Registry in Japan) (2.1 ± 0.1 vs 2.2 ± 0.1; P = 0.279), PROGRESS CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention) (1.3 ± 0.9 vs 1.1 ± 1.0; P = 0.058) and PROGRESS CTO complication (2.4 ± 1.8 vs 2.3 ± 1.8; P = 0.561) scores and use of the retrograde approach (11% vs 14%; P = 0.342) were similar in the TRA and TFA groups. TRA was noninferior to TFA for procedural success (84% vs 86%; P = 0.563) but had fewer access-site complications (2.0% vs 5.6%; P = 0.019). There was no difference between TFA and TRA in procedural duration, contrast volume, or radiation dose.

CONCLUSIONS

TRA was noninferior to TFA for CTO PCI but had fewer access-site complications.