Impact of lesion morphology on angiographic and clinical outcomes in patients with chronic total occlusion after recanalization with drug-eluting stents: a multislice computed tomography study

Full-Moon Coronary Calcification as Detected With Computed Tomography Angiography in Chronic Total Occlusion Percutaneous Coronary Intervention

"Full moon" is a central calcification that occludes the entire vessel on coronary computed tomography angiography (CCTA). We examined the association of full moon calcification as identified by CCTA, on clinical and procedural outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We studied patients who underwent elective CTO-PCI in 2 European centers and had preprocedural CCTA. The primary end point was the inability to cross the lesion and/or the need for extensive debulking techniques. Secondary end points were procedural success, in-hospital cardiac mortality, the need for extensive debulking techniques, myocardial infarction, major adverse cardiac events (defined as in-hospital death, myocardial infarction, and clinically driven target vessel revascularization), and stent thrombosis. Secondary procedural end points included procedural time, fluoroscopy time, number of guidewires and balloons, stent length, number and diameter, and contrast volume. Multivariable logistic regression analysis was performed, identifying potential covariates related to the primary outcome according to knowledge and previous studies. Subsequently, a stepwise selection approach was performed to select factors with the greatest predictive value. Of 140 patients included, 28 (20%) had a full moon calcified CTO plaque. Patients in the full moon group were older and had more cardiovascular risk factors. There was not significant difference in the need for retrograde approach and anterograde dissection and reentry techniques between the full moon group and the other groups (32.1% vs 37.5%, p = 0.59 and 0% vs 1.7%, p = 0.47, respectively). Patients in the full moon group had greater incidence of the primary outcome than did those who did not have full moon morphology (53.5% vs 12.5%, p <0.001). On multivariable analysis that included chronic kidney failure and previous coronary artery bypass surgery, full moon calcification was associated with greater incidence of the primary end point (odds ratio 6.5, 95% confidence interval 2.1 to 20.5, p = 0.001). Moreover, less procedural success (71.4% vs 87.5%, p = 0.03), greater incidence of coronary perforations (14.2% vs 3.5%, p <0.02), and greater procedural (172.5 [118.0 to 237.5] vs 144.0 [108.50 to 174.75], p = 0.02) and fluoroscopic time (62.6 [38.1 to 83.0] vs 42.8 [29.5 to 65.7], p = 0.03) were observed in the full moon group. Overall major adverse cardiac events did not differ between the 2 groups (1 patient in the full moon group vs 1 patient in the non-full moon group; 3.5% vs 0.8%, p = 0.29). In conclusion, full moon calcification on CCTA was independently associated with procedural complexity and adverse outcomes in CTO-PCI.

The added value of coronary CTA in chronic total occlusion percutaneous coronary intervention: a systematic review and meta-analysis

OBJECTIVES

To systematically investigate and summarize the utility of coronary computed tomographic angiography (CCTA) in the management of chronic total occlusion (CTO)-percutaneous coronary intervention (PCI).

METHODS

The authors searched the four databases between 2005 and 2023 for studies investigating the role of CCTA and invasive coronary angiograms (ICA) images when used as the pre-procedural tool for CTO-PCI. Efficacy and safety of CCTA in CTO-PCI treatment as a pre-procedural assessment tool was evaluated.

RESULTS

Forty-seven studies were finally chosen for this systematic review. CCTA had a high degree of agreement with ICA when applied for J-CTO scoring system. A J-CTO (Multicenter CTO Registry in Japan) score > 3, together with calcification, occlusion length ≥ 20 mm, blunt stump, and bending > 45° were shared imaging risk factors on both ICA and CCTA for technique failure and guidewire crossing over 30 min. Additionally, negative remodeling and multiple diseased vessel were significant indicators on CCTA. Although patients with pre-procedural CCTA showed a trend of higher success rate and easier guidewire crossing, and CCTA showed a slightly higher predictive accuracy for process success, no significant improvement in post-PCI major adverse cardiac events of using CCTA for assessment has been achieved.

CONCLUSIONS

CCTA is a safe and effective pre-operative tool of CTO-PCI. Except for the shared imaging risk factors with ICA for a hard CTO-PCI including calcification, occlusion length ≥ 20 mm, blunt stump, bending > 45°, and J-CTO score > 3, factors like negative remodeling and multiple diseased vessel were also recognized as significant pre-operative assessment indicators on CCTA.

CLINICAL RELEVANCE STATEMENT

A pre-procedural assessment based on coronary computed tomographic angiography has the potential to aid in the management of chronic total occlusion percutaneous coronary intervention.

KEY POINTS

• A coronary computed tomographic angiography-based pre-procedural assessment can help chronic total occlusion-percutaneous coronary intervention management. • The recognized high-risk features detected via coronary computed tomographic angiography and invasive coronary angiograms are comparable in detecting difficult lesions and chronic total occlusion-percutaneous coronary intervention failure. • Coronary computed tomographic angiography has an additional value to be a safe and effective pre-procedural assessment tool for chronic total occlusion-percutaneous coronary intervention.

Mechanisms of Cardiovascular Calcification and Experimental Models: Impact of Vitamin K Antagonists

Cardiovascular calcification is a multifactorial and complex process involving an array of molecular mechanisms eventually leading to calcium deposition within the arterial walls. This process increases arterial stiffness, decreases elasticity, influences shear stress events and is related to an increased risk of morbidity and mortality associated with cardiovascular disease. In numerous in vivo and in vitro models, warfarin therapy has been shown to cause vascular calcification in the arterial wall. However, the exact mechanisms of calcification formation with warfarin remain largely unknown, although several molecular pathways have been identified. Circulating miRNA have been evaluated as biomarkers for a wide range of cardiovascular diseases, but their exact role in cardiovascular calcification is limited. This review aims to describe the current state-of-the-art research on the impact of warfarin treatment on the development of vascular calcification and to highlight potential molecular targets, including microRNA, within the implicated pathways.

SCAI Expert Consensus Statement on the Management of Calcified Coronary Lesions

The prevalence of calcification in obstructive coronary artery disease is on the rise. Percutaneous coronary intervention of these calcified lesions is associated with increased short-term and long-term risks. To optimize percutaneous coronary intervention results, there is an expanding array of treatment modalities geared toward calcium modification prior to stent implantation. The Society for Cardiovascular Angiography and Interventions, herein, puts forth an expert consensus document regarding methods to identify types of calcified coronary lesions, a central algorithm to help guide use of the various calcium modification strategies, tips for when using each treatment modality, and a look at future studies and trials for treating this challenging lesion subset.

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.

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

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

The Impact of Calcium on Chronic Total Occlusion Management

Coronary artery calcification is prevalent in chronic total occlusions (CTO), particularly in those of longer duration and post-coronary artery bypass. The presence of calcium predicts lower procedural success rates and a higher risk of complications of CTO percutaneous coronary intervention. Adjunctive imaging, including pre-procedural computed tomography and intracoronary imaging, are useful to understand the distribution and morphology of the calcium. Specialised guidewires and microcatheters, as well as penetration, subintimal entry and luminal re-entry techniques, are required to cross calcific CTOs. The use of both atherectomy devices and balloon-based calcium modification tools has been reported during CTO percutaneous coronary intervention, although they are limited by concerns regarding safety and efficacy in the subintimal space.

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

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

Predictors of successful chronic total occlusion percutaneous coronary interventions: a systematic review and meta-analysis

OBJECTIVE

The aim of this study was to identify positive and negative predictors of technical and clinical success for percutaneous coronary intervention (PCI) of chronic total occlusions (CTO).

METHODS

We conducted a systematic review and meta-analysis of studies published between 2000 and 2016 analysing rates of CTO PCI success with respect to demographic and angiographic characteristics. Crude ORs and 95% CIs for each predictor were calculated using a random effects model. Predictors of technical and clinical success were assessed among 28 demographic and 31 angiographic variables. Clinical success was defined as technical success without major adverse cardiac events.

RESULTS

A total of 61 studies, totalling 69 886 patients were included in this analysis. The major demographic characteristics associated with a 20% or greater reduction in the odds of technical and clinical success were a history of myocardial infarction, PCI, coronary artery bypass grafting, stroke/transient ischaemic attack and peripheral vascular disease. Angiographic factors were generally stronger predictors of reduced technical and clinical success. Those associated with >20% odds reduction included non-left anterior descending CTOs, multivessel disease, presence of bridging collaterals, moderate-to-severe calcification, >45 degree vessel bending, tortuous vessel, blunt stump and ostial lesions. Of these, novel predictors included prior PCI, prior stroke, peripheral vascular disease, presence of multivessel disease and bridging collaterals.

CONCLUSION

The present study has identified strong negative predictors for clinical success for CTO PCI, which will aid in patient selection for this procedure.

Impact of Calcium on Chronic Total Occlusion Percutaneous Coronary Interventions

We sought to examine the impact of calcific deposits on the outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). The outcomes of 1,476 consecutive CTO PCIs performed in 1,453 patients (65.5 ± 10 years, 85% male) between 2012 and 2016 at 11 US centers were evaluated. Moderate or severe quantity of calcium was present in 58% of target lesions. Calcified lesions were more tortuous and more likely to have proximal cap ambiguity and interventional collaterals. PCI of moderately/severely calcified CTOs more often required use of the retrograde approach (54% vs 30%, p <0.001) and was associated with longer procedure and fluoroscopy time and higher air kerma radiation dose and contrast volume. Moderate/severe quantity of calcium was associated with lower technical (86.6% vs 93.8%, p <0.001) and procedural (84.4% vs 92.7%, p <0.001) success rates and higher incidence of major adverse cardiac events (3.7% vs 1.8%, p = 0.033). On multivariate analysis, the presence of moderate/severe quantity of calcium was not independently associated with technical success. Balloon angioplasty was the most common lesion preparation technique for calcified lesions, followed by rotational atherectomy and laser. To conclude, in a contemporary, multicenter registry, moderate/severe calcific deposits were present in 58% of attempted CTO lesions and were associated with higher use of the retrograde approach, lower success, and higher complication rates. However, on multivariable analysis, the amount of calcium was not independently associated with technical success.

Approach to CTO Intervention: Overview of Techniques

OPINION STATEMENT

Successful percutaneous coronary intervention (PCI) of chronic total occlusions (CTOs) has been associated with significant clinical benefits, but remains technically demanding. Failure to cross the CTO with a guidewire is the most common cause of CTO PCI failure. CTO crossing can be achieved in the antegrade or retrograde direction and can be accomplished by maintaining true lumen position throughout or via subintimal dissection/reentry techniques. A procedural plan should be created prior to the procedure through careful angiographic review of four key parameters: (a) morphology of the proximal occlusion cap; (b) length of the occlusion; (c) quality of the distal vessel and presence of bifurcation at the distal cap; and (d) suitability of collateral circulation for retrograde crossing. Dual coronary injection is recommended in all cases with contralateral collaterals for detailed characterization of the lesion. If one approach fails to progress, a quick transition to the next approach is encouraged to maximize efficacy and efficiency. Procedural complications, including vessel perforation, may occur more frequently in CTO as compared with non-CTO PCI; hence, availability of necessary equipment and expertise in treating such complications are essential.

Procedural and one-year clinical outcomes of bioresorbable vascular scaffolds for the treatment of chronic total occlusions: a single-centre experience

Introduction

The bioresorbable vascular scaffold system (BVS) is the latest fully absorbable vascular therapy system that is used to treat coronary artery disease. The BVS has been used in different coronary lesion subsets, such as acute thrombotic lesions, bifurcation lesions, ostial lesions and lesions originating from bypass grafts. However, data about the use of BVS in chronic total occlusions (CTO) are limited. We report our BVS experience for the treatment of CTOs in terms of procedural features and one-year clinical follow-up results.

Methods

An analysis was made of 41 consecutive patients with CTO lesions who were referred to our clinic between January 2013 and December 2014. A total of 52 BVS were implanted. An analysis was made of patient characteristics, procedural features [target vessel, BVS diameter, BVS length, post-dilatation rate, type of post-dilatation balloon, procedure time, fluoroscopy time, contrast volume, postprocedure reference vessel diameter (RVD), post-procedure minimal lesion diameter (MLD), type of CTO technique and rate of microcatheter use] and one-year clinical follow-up results [death, myocardial infarction, angina, coronary artery bypass graft (CABG), target-lesion revascularisation (TLR) and target-vessel revascularisation (TVR)]. Descriptive and frequency statistics were used for statistical analysis.

Results

The mean age of the patient group was 61.9 ± 9.7 years, 85.4% were male, and 51.2 % had diabetes. Prior myocardial infarction incidence was 65.9%, 56.1% of the patients had percutaneous coronary intervention and 17.1% had a previous history of CABG. The procedure was performed via the radial route in 24.3% of the patients. The target vessel was the right coronary artery in 48.7% of the patients. Post-dilatation was performed on the implanted BVS in 97.5% of the patients, mainly by non-compliant balloon; 87.8% of the BVS were implanted by the antegrade CTO technique. Mean procedure time was 92 ± 35.6 minutes. Mean contrast volume was 146.6 ± 26.7 ml.

At one year, there were no deaths. One patient had lesionrelated myocardial infarction and needed revascularisation because of early cessation of dual anti-platelet therapy. Eleven patients had angina and five of them needed target-vessel revascularisation.

Conclusions

BVS implantation appeared to be effective and safe in CTO lesions but randomised studies with a larger number of patients and with longer follow-up times are needed

Theory and practical based approach to chronic total occlusions

Coronary chronic total occlusions (CTOs) represent the most technically challenging lesion subset that interventional cardiologists face. CTOs are identified in up to one third of patients referred for coronary angiography and remain seriously undertreated with percutaneous techniques. The complexity of these procedures and the suboptimal success rates over a long period of time, along with the perception that CTOs are lesions with limited scope for recanalization, account for the underutilization of CTO Percutaneous Coronary Intervention (PCI). During the last years, dedicated groups of experts in Japan, Europe and United States fostered the development and standardization of modern CTO recanalization techniques, achieving success rates far beyond 90%, while coping with lesions of increasing complexity. Numerous studies support the rationale of CTO revascularization following documentation of viability and ischemia in the territory distal to the CTO. Successful CTO PCI provide better tolerance in case of future acute coronary syndromes and can significantly improve angina and left ventricular function. Randomized trials are on the way to further explore the prognostic benefit of CTO revascularization. The following review reports on the theory and the most recent advances in the field of CTO recanalization, in an attempt to promote a more balanced approach in patients with chronically occluded coronary arteries.