Preprocedural coronary CT angiography significantly improves success rates of PCI for chronic total occlusion

Preprocedural Planning for Chronic Total Occlusion Percutaneous Coronary Intervention

Chronic total occlusions (CTO) are frequently encountered in clinical practice. Although the success rates and safety of CTO percutaneous coronary intervention (PCI) have significantly improved with the development of newer equipment, use of an algorithmic approach, and advancement in procedural techniques, CTO PCI has a higher rate of complication than does non-CTO PCI. Therefore, meticulous preprocedural planning before CTO PCI is paramount to improve success and reduce the risk of complications. In this report, we review multiple aspects of preprocedural CTO PCI planning, including procedural indications, efficacy, safety, diagnostic angiography, scoring tools for procedural success and risk prediction, and preprocedural use of computed tomography coronary angiography.

Role of pre-procedure CCTA in predicting failed percutaneous coronary intervention for chronic total occlusions

Purpose

This study aimed to identify major lesion characteristics of chronic total occlusions (CTOs) that predict failed percutaneous coronary intervention (PCI) using pre-procedure coronary computed tomography angiography (CCTA) in combination with conventional coronary angiography (CCA).

Methods

Consecutive patients with at least one CTO of the native coronary arteries received CCTA and CCA-guided PCI, with computed tomography performed before or during PCI.

Results

A total of 76 patients with CTO were included in this study. 76 patients were divided into successful and failed PCI groups based on their PCI outcome. There were 62 (81.58 %) patients in the successful PCI group and 14 (18.42 %) in the failed PCI group. The occlusion length ≥20 mm, ostial or bifurcation lesions, negative remodeling, microchannels, and good collateral vessels were the CCTA morphologic parameters associated with PCI outcome (P<0.05). In addition, the blunt stump, occlusion length ≥20 mm, and ostial or bifurcation lesions, were the CCA morphologic parameters associated with PCI outcome (P<0.05). The multivariate regression model showed that the three independent negative predictors: blunt stump on CCA (OR: 0.63; 95 % CI: 0.23-0.98; p =0.048), occlusion length ≥20 mm on CCTA (OR: 0.37; 95 % CI: 0.32-0.71; p <0.001) and negative remodeling on CCTA (OR: 0.26; 95 % CI: 0.28-0.44; p <0.001).

Conclusion

Our study demonstrated that combining CCTA and CCA morphologic characteristics could improve PCI outcome prediction in patients with CTO compared to CCTA morphologic features alone.

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.

Coronary chronic total occlusion on coronary CT angiography: what radiologists should know?

Coronary chronic total occlusion (CTO) often occurs in patients with obstructive coronary artery disease, which remains one of the greatest challenges for interventional cardiologists. Coronary computed tomography angiography (CCTA) with its emerging post-processing techniques can provide a detailed assessment of CTO lesions before percutaneous coronary intervention (PCI), playing an important role in the clinical management of CTO PCI, from early diagnosis, pre-procedural outcome prediction, the crossing algorithm planning, intraprocedural guidance, and finally post-procedural assessment and follow-up. In addition, the feasibility of CT perfusion (CTP) in patients with CTO has been validated. Combined CCTA and CTP have the great potential to be the one-stop-shop imaging modality for assessing both anatomy and function of CTO lesions. This review aims to make radiologists understand the role of CCTA in the diagnosis and assessment of CTO lesions, thus assisting interventionalists in optimizing CTO PCI crossing strategies with the expertise of radiologists.Critical relevance statement The anatomical features of CTO on CCTA can reveal the complexity of CTO lesions and are associated with CTO PCI outcome, thus helping interventionalists optimize CTO PCI crossing strategies.Key points • CTO is the common lesion in invasive coronary angiography, and CTO PCI is technically difficult and its success rate is relatively low.• Length, collaterals, and attenuation-related signs can help distinguish CTO from subtotal occlusion.• The anatomical features of CTO lesions can help grade the difficulty of CTO PCI and predict procedural outcomes and long-term outcomes of CTO PCI.• The real-time fusion of CCTA with fluoroscopic angiography can be applied in highly complicated CTO lesions.• After CTO PCI, CCTA can help guide a second CTO PCI re-entry or follow up stent patency.

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

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

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.

The Utility of CT Coronary Angiography in Chronic Total Occlusion Percutaneous Coronary Intervention

Chronic total occlusion (CTO) of the coronary arteries is a relatively common finding in routine coronary angiography. Of late, there has been considerable improvement in the success rate of percutaneous intervention for coronary CTO, attributed to technological advancement and skills development. CT coronary angiogram (CTCA) is a simple, non-invasive, and cost-effective test that aids in the diagnosis and management of coronary artery disease, including CTOs. The development of multi-slice CT and the use of 3D volume rendering images has revolutionised the diagnostic abilities of CTCA, with improvements in imaging quality and detailed anatomical and morphological characterisation of the plaque disease. In CTO percutaneous intervention, CTCA is used in pre-procedural planning, applying scoring systems to predict the likely success of the intervention as well as the post-procedural evaluation and follow-up. This review examines the different uses of CTCA in CTO intervention, its impact on successful recanalisation and the areas for future consideration.

Predictive performance of J-Calc-CTO score for guidewire crossing through chronic total occlusion lesions within 30 minutes: J-CTO score modified by computed tomography coronary angiography

The original J-CTO score predicts the difficulty of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) lesions, but the grade of calcification has not been fully evaluated. We examined 137 patients (141 CTO lesions) who underwent coronary computed tomography angiography (CTA) pre-PCI between October 2016 and October 2021. They were randomly divided into derivation (n = 94) and validation (n = 47) groups. The degree and distribution of calcification in the occluded segment were assessed using CTA. The calcified index was defined as calcium volume divided by the length of the occluded segment. We created the J-Calc-CTO score consisting of calcification parameters associated with 30-min wire crossing in the derivation group. The validity of the J-Calc-CTO score was compared with that of the original J-CTO score using c-statistics. The procedural success rate was 96%, and 30-min wire crossing during the procedure was achieved in 29%. Dense calcification (calcified-index >12) (odds ratio [OR]: 4.63; 95% confidence interval [CI]: 1.24-22.2; p = 0.04) and calcification in the center of the lumen (OR: 7.25; 95% CI: 1.48-32.1; p = 0.02) were independently associated with 30-min wire crossing as variables evaluated using CTA. The J-Calc-CTO score was created by adding 1 point to the two parameters in place of "calcification" in the original J-CTO score. The J-Calc-CTO score showed a higher predictive value of 30-min wire crossing than the J-CTO score in the derivation (c-statistics; 0.836 vs. 0.670; p > 0.01) and validation groups (c-statistics; 0.879 vs. 0.767, p > 0.01). The degree and distribution of calcification evaluated using CTA refined the predictive value of the original J-CTO score for 30-min wire crossing.

The Role of Multimodality Imaging for Percutaneous Coronary Intervention in Patients With Chronic Total Occlusions

Background

Percutaneous coronary intervention (PCI) of Chronic total occlusions (CTOs) has been traditionally considered a challenging procedure, with a lower success rate and a higher incidence of complications compared to non-CTO-PCI. An accurate and comprehensive evaluation of potential candidates for CTO-PCI is of great importance. Indeed, assessment of myocardial viability, left ventricular function, individual risk profile and coronary lesion complexity as well as detection of inducible ischemia are key information that should be integrated for a shared treatment decision and interventional strategy planning. In this regard, multimodality imaging can provide combined data that can be very useful for the decision-making algorithm and for planning percutaneous CTO recanalization.

Aims

The purpose of this article is to appraise the value and limitations of several non-invasive imaging tools to provide relevant information about the anatomical characteristics and functional impact of CTOs that may be useful for the pre-procedural assessment and follow-up of candidates for CTO-PCI. They include echocardiography, coronary computed tomography angiography (CCTA), nuclear imaging, and cardiac magnetic resonance (CMR). As an example, CCTA can accurately delineate CTO location and length, distal coronary bed, vessel tortuosity and calcifications that can predict PCI success, whereas stress CMR, nuclear imaging and stress-CT can provide functional evaluation in terms of myocardial ischemia and viability and perfusion defect extension.

Accuracy of the Euro CTO(CASTLE) score obtained on coronary computed tomography angiography for Predicting 30-minute wire crossing in chronic total occlusions

Background

To investigate the feasibility and accuracy of the Euro CTO (CASTLE)_CTA score obtained on coronary computed tomography angiography (CCTA) for predicting the success of percutaneous coronary intervention (PCI) and the 30-min wire crossing in chronic total occlusions (CTO).

Method

One hundred and fifty patients (154 CTO cases; median age, 61 (interquartile range [IQR], 54–68) years; 75.3% male) received CCTA at the People's Hospital of Liaoning Provincce within 1 month before the procedure. The Euro CTO (CASTLE) score obtained on CCTA(CASTLE_CTA) was calculated and compared with the Euro CTO (CASTLE) score obtained based on coronary angiography (CASTLE_CAG) for the predictive value of 30-min wire crossing and CTO procedural success.

Results

In our study, the CTO-PCI success rate was 89.0%, with guidewires of 65 cases (42.2%) crossing within 30 min. There were no significant differences in the median CASTLE_CTA and CASTLE_CAG scores in the procedure success group (3 [IQR, 2–4] vs 3 (IQR, 2–3]; p = 0.126). However, the median CASTLE_CTA score was significantly higher than the median CASTLE_CAG score in the procedure failure group (4 [IQR, 3–5.5] vs 4 [IQR, 2.5–5.5]; p = 0.021). There was no significant difference between the median CASTLE_CTA score and the median CASTLE_CAG score in the 30-min wire crossing failure group (3 [IQR, 3–4] vs 3 [IQR, 2–4]; p = 0.254). However, the median CASTLE_CTA score was significantly higher than the median CASTLE_CAG score in the 30-min wire crossing group (3 [IQR, 2–3] vs 2 [IQR, 2–3]; p < 0.001). The CASTLE_CTA score described higher levels of calcification than the CASTLE_CAG score (48.1% vs 33.8%; p = 0.015). There was no significant difference between the CASTLE_CTA score (area under the curve [AUC], 0.643; 95% confidence interval [CI], 0.561–0.718) and the CASTLE_CAG score (AUC, 0.685; 95% CI, 0.606–0.758) for predicting procedural success (p = 0.488). The CASTLE_CTA score (AUC, 0.744; 95% CI, 0.667–0.811) was significantly better than the CASTLE_CAG score (AUC, 0.681; 95% CI, 0.601–0.754; p = 0.046) for predicting 30-min wire crossing with the best cut-off value being CASTLE_CTA ≤ 3. The sensitivity, specificity, positive predictive value, and negative predictive value were 90.8%, 55.2%, 54.6%, and 87.0%, respectively.

Conclusion

The CASTLE_CTA scores obtained from noninvasive CCTA perform better for the prediction of the 30-min wire crossing than the CASTLE_CAG score.

Coronary CT Angiography to Guide Percutaneous Coronary Intervention

Coronary CT angiography (CCTA) has emerged as a powerful noninvasive tool for characterizing the presence, extent, and severity of coronary artery disease (CAD) in patients with stable angina. Recent technological advancements in CT scanner hardware and software have augmented the rich information that can be derived from a single CCTA study. Beyond merely identifying the presence of CAD and assessing stenosis severity, CCTA now allows for the identification and characterization of plaques, lesion length, and fluoroscopic angle optimization, as well as enables the assessment of the physiologic extent of stenosis through CT-derived fractional flow reserve, and may even allow for the prediction of the response to revascularization. These and other features make CCTA capable of not only guiding invasive coronary angiography referral, but also give it the unique ability to help plan coronary intervention. This review summarizes current and future applications of CCTA in procedural planning for percutaneous coronary intervention, provides rationale for wider integration of CCTA in the workflow of the interventional cardiologist, and details how CCTA may help improve patient care and clinical outcomes. Keywords: CT Angiography © RSNA, 2022.

The indications and utility of adjunctive imaging modalities for chronic total occlusion (CTO) intervention

Coronary chronic total occlusions (CTO) are common in patients undergoing coronary angiography, yet the optimal management strategy remains uncertain, with conflicting results from randomized trials. Appropriate patient selection and careful periprocedural planning are imperative for successful patient management. We review the role of adjunctive imaging modalities including myocardial perfusion imaging (MPI), cardiac magnetic resonance imaging (CMR), echocardiography and computed tomography coronary angiography (CTCA) in myocardial ischemic quantification, myocardial viability assessment, as well as procedural planning for CTO revascularization. An appreciation of the value, indications and limitations of these modalities prior to planned intervention are essential for optimal management.

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.

Non-invasive Imaging in Patients With Chronic Total Occlusions of the Coronary Arteries-What Does the Interventionalist Need for Success?

Chronic total occlusion (CTO) of coronary arteries is a common finding in patients with known or suspected coronary artery disease (CAD). Although tremendous advances have been made in the interventional treatment of CTOs over the past decade, correct patient selection remains an important parameter for achieving optimal results. Non-invasive imaging can make a valuable contribution. Ischemia and viability, two major factors in this regard, can be displayed using echocardiography, single-photon emission tomography, positron emission tomography, computed tomography, and cardiac magnetic resonance imaging. Each has its own strengths and weaknesses. Although most have been studied in patients with CAD in general, there is an increasing number of studies with positive preselectional factors for patients with CTOs. The aim of this review is to provide a structured overview of the current state of pre-interventional imaging for CTOs.

Effect of Coronary CTA on Chronic Total Occlusion Percutaneous Coronary Intervention: A Randomized Trial

OBJECTIVES

The purpose of this study was to test whether the success rate of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) increased with pre-procedural coronary computed tomography angiography (CTA).

BACKGROUND

Coronary CTA provides valuable information before and during CTO-PCI. However, there are no randomized data that explore whether coronary CTA increases its success rate.

METHODS

In this multicenter, randomized trial, a total of 400 patients with CTO were randomized to receive PCI with pre-procedural coronary CTA (coronary CTA-guided group; n = 200) or without coronary CTA (angiography-guided group; n = 200) between January 2014 and September 2019. The primary endpoint was the successful recanalization rate, a final TIMI (Thrombolysis In Myocardial Infarction) grade ≥2, and ≤30% residual stenosis on the final angiogram.

RESULTS

A total of 10 operators performed PCI. Successful recanalization was achieved in 187 patients (93.5%) in the coronary CTA-guided group and in 168 patients (84.0%) in the angiography-guided group (absolute difference, 9.5% [95% confidence interval: 3.4% to 15.6%]; p = 0.003). When comparing the success rates according to the Multicenter CTO Registry of Japan score (J-CTO), the coronary CTA guidance was favored over the angiography-guidance in the subset of J-CTO ≥2 versus in the subset of J-CTO <2 (p interaction = 0.035). Coronary perforations occurred in 2 (1%) and 8 patients (4%) in the coronary CTA- and angiography-guided groups, respectively (p = 0.055). Periprocedural myocardial infarction was not observed in the coronary CTA-guided group, whereas it occurred in 4 patients (2%) in the angiography-guided group (p = 0.123). Total procedure and fluoroscopic times were not different. There were no differences between the groups in the occurrences of cardiac death, target vessel-related myocardial infarction, or target-vessel revascularization at 1 year.

CONCLUSIONS

Pre-procedural coronary CTA-guidance for CTO resulted in higher success rates with numerically fewer immediate periprocedural complications such as coronary perforations or periprocedural myocardial infarction than angiography guidance. Higher success rates were more prominently observed in patients with CTO who had a high J-CTO score than those who did not. (Role of CT Scan for the Successful Recanalization of Chronic Total Occlusion; a Randomized Comparison Between 3D CT-guided PCI vs. Conventional Treatment [CT-CTO Trial]; NCT02037698).

Preprocedural computed tomography angiography in differentiating chronic total from subtotal coronary occlusions

INTRODUCTION

Differentiation of chronic total occlusion (CTO) from subtotal coronary occlusions (STOs) is often difficult to make from coronary angiography. These differences are very important, as the technical expertise and tools required are significantly different for revascularization of these lesions. We sought to determine if preprocedural computed tomography angiography (CTA) can help better diagnose and differentiate CTO from STO.

METHODS

We searched three databases (Ovid MEDLINE, EMBASE, EBM reviews) from 1 January 1946 to 1 March 2019. Studies reporting on the use of computed tomography (CT) to aid in CTO revascularization were included. Case reports and case series were excluded.

RESULTS

We identified 577 articles, and using the Preferred Reporting Items for Systematic Reviews and Meta-analyses method, 4 articles met prespecified inclusion criteria. A total of 669 patients were included. The statistically significant CT-derived parameters determined to help differentiate CTO from STO were found to include longer lesion length (four out of four studies), larger contrast density difference (one out of four studies), presence of collaterals (two out of four studies) and the presence of the reverse attenuation gradient sign (two out of four studies).

CONCLUSION

This systematic review shows the utility of preprocedural CTA to help differentiate CTO from STO using a number of CT-derived parameters as above. Further, this study highlights the need for further research to develop specific validated parameters for differentiation of CTO and STO.

Practical utilization of cardiac computed tomography for the success in complex coronary intervention

Percutaneous coronary intervention (PCI) for complex lesions is still technically demanding and is associated with less favorable procedural parameters such as lower success rate, longer procedural time, higher contrast volume and unexpected complications. Because the conventional angiographic analysis is limited by the inability to visualize the plaque information and the occluded segment, cardiac computed tomography has evolved as an adjunct to invasive angiography to better characterize coronary lesions to improve success rates of PCI. Adding to routine image reconstructions by coronary computed tomography angiography, the thin-slab maximum intensity projection method, which is a handy reconstruction technique on an ordinary workstation, could provide easy-to-understand images to reveal the anatomical characteristics and the lumen and plaque information simultaneously, and then assist to build an in-depth strategy for PCI. Especially in the treatment of chronic total occlusion lesion, these informations have big advantages in the visualization of the morphologies of entry and exit, the occluded segment and the distribution of calcium compared to invasive coronary angiography. Despite of the additional radiation exposure, contrast use and cost for cardiac computed tomography, the precise analysis of lesion characteristics would consequently improve the procedural success and prevent the complication in complex PCI.

CT Angiography-Derived RECHARGE Score Predicts Successful Percutaneous Coronary Intervention in Patients with Chronic Total Occlusion

Objective

To investigate the feasibility and the accuracy of the coronary CT angiography (CCTA)-derived Registry of Crossboss and Hybrid procedures in France, the Netherlands, Belgium and United Kingdom (RECHARGE) score (RECHARGE_CCTA) for the prediction of procedural success and 30-minutes guidewire crossing in percutaneous coronary intervention (PCI) for chronic total occlusion (CTO).

Materials and Methods

One hundred and twenty-four consecutive patients (mean age, 54 years; 79% male) with 131 CTO lesions who underwent CCTA before catheter angiography (CA) with CTO-PCI were retrospectively enrolled in this study. The RECHARGE_CCTA scores were calculated and compared with RECHARGE_CA and other CTA-based prediction scores, including Multicenter CTO Registry of Japan (J-CTO), CT Registry of CTO Revascularisation (CT-RECTOR), and Korean Multicenter CTO CT Registry (KCCT) scores.

Results

The procedural success rate of the CTO-PCI procedures was 72%, and 61% of cases achieved the 30-minutes wire crossing. No significant difference was observed between the RECHARGE_CCTA score and the RECHARGE_CA score for procedural success (median 2 vs. median 2, p = 0.084). However, the RECHARGE_CCTA score was higher than the RECHARGE_CA score for the 30-minutes wire crossing (median 2 vs. median 1.5, p = 0.001). The areas under the curve (AUCs) of the RECHARGE_CCTA and RECHARGE_CA scores for predicting procedural success showed no statistical significance (0.718 vs. 0.757, p = 0.655). The sensitivity, specificity, positive predictive value, and the negative predictive value of the RECHARGE_CCTA scores of ≤ 2 for predictive procedural success were 78%, 60%, 43%, and 87%, respectively. The RECHARGE_CCTA score showed a discriminative performance that was comparable to those of the other CTA-based prediction scores (AUC = 0.718 vs. 0.665–0.717, all p > 0.05).

Conclusion

The non-invasive RECHARGE_CCTA score performs better than the invasive determination for the prediction of the 30-minutes wire crossing of CTO-PCI. However, the RECHARGE_CCTA score may not replace other CTA-based prediction scores for predicting CTO-PCI success.

A computed tomography algorithm for crossing coronary chronic total occlusions: riding on the wave of the proximal cap and distal vessel segment

With wider adoption of coronary computed tomography angiography (coronary CTA), chronic total occlusions (CTOs) are being increasingly identified and characterised by non-invasive angiography. In particular, the ability of coronary CTA to clearly delineate atherosclerotic plaque, as well as to display three-dimensional vessel trajectories, has garnered particular attention in the context of preprocedural planning and periprocedural guidance of CTO percutaneous coronary intervention (PCI). Single CTO features and combined scoring systems derived from CTA (mostly exceeding the diagnostic performance of the angiographic J‑CTO score) have been used to predict time-efficient guidewire crossing, and thus grade the CTO difficulty level prior to PCI. In addition, the introduction of three-dimensional CTA/fluoroscopy co-registration for periprocedural navigation during CTO PCI offers the unprecedented opportunity to resolve proximal cap ambiguity and clearly visualise the distal CTO segment, thereby potentially influencing CTO PCI strategies and techniques. In this review, the potential advantages of non-invasive evaluation of CTO by coronary CTA are described, and a CTA-based hybrid algorithm is introduced for further enhancing the efficiency of CTO PCI. Further studies are clearly needed to verify the proposed approach. However, several luminary operators have already implemented coronary CTA for planning and periprocedural guidance of CTO interventions using the hybrid algorithm.

Efficacy of Coronary Computed Tomography Angiography for the De Novo Detection of Chronic Total Occlusion Prior to Coronary Angiography: A Preliminary and Retrospective Study

Coronary computed tomography angiography (CCTA) offers high-resolution anatomic characterization of the coronary vasculature but may be suboptimal for lesions dependent on real-time visualization of flow including chronic total occlusion (CTO). In CTOs, heavy calcification and distal vessel opacification from collateralization may confound luminal assessment. Several studies have examined the role of CCTA in characterizing known CTOs to guide percutaneous coronary intervention (PCI). However, the efficacy of CCTA in the de novo diagnosis of CTOs prior to coronary angiography (CAG) has not been demonstrated. A total of 233 consecutive patients who presented for CAG within a 3-month period of having CCTA were retrospectively reviewed. Those patients with prior diagnosis of CTO or prior bypass of the occluded vessels were excluded. Sensitivity and specificity analysis of CCTA in identifying CTOs using CAG as the gold standard was performed. The prevalence of CTO was 21.11% in the population that met criteria for analysis (n = 199). The sensitivity of CCTA in predicting CTO was 57.1%, while the specificity was 96.8%. The positive predictive value and negative predictive value of CCTA in detection of CTO were 82.8 and 89.4%, respectively. Our study shows that CCTA has excellent specificity but poor sensitivity in the detection of CTO thus limiting its clinical use in de novo diagnosis. Further studies to determine the effect of de novo CTO diagnosis on clinically important procedural factors, such as radiation exposure, contrast use, and need for repeat procedures, are warranted and may implicate a role for CCTA in this setting.

Noninvasive Imaging Risk Stratification with Computed Tomography Angiography for Coronary Artery Disease

The recent technological evolution of coronary computed tomography angiography (CTA) with improved sensitivity and high negative predictive value has extended its potential applications as a gatekeeper test before invasive coronary angiography. However, the definition of the most accurate diagnostic algorithms comprising CTA as a first-line strategy for ruling out coronary artery disease and the correct management of the patients according to the results of imaging tests still warrant better definition.

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.

Functional and Anatomical Imaging in Patients with Ischemic Symptoms and Known Coronary Artery Disease

PURPOSE OF REVIEW

This review is aimed at summarizing recent advances in functional, anatomical, and hybrid imaging techniques used in the assessment of ischemic complaints in patients with known coronary artery disease (CAD).

RECENT FINDINGS

Cardiovascular imaging has seen significant growth over the last decade in the fields of coronary computed tomography angiography (CCTA), FFR derived from CCTA, cardiac magnetic resonance, radionuclide myocardial perfusion imaging, and hybrid imaging for the purposes of evaluating symptoms concerning for ischemia. This growth stems from refinement of imaging techniques and hardware and software advances that have made current techniques more accurate with less acquisition time. However, every anatomic and functional imaging modality has important technical and patient-specific limitations. This review assesses these issues, guides a patient-centered imaging approach, and identifies important research questions to resolve. Recent advances in non-invasive cardiovascular imaging can provide important information in patients with known CAD beyond traditional imaging techniques; the use of these novel tools refines the clinical management of complex patients with ischemic symptoms and known CAD.

CT support of cardiac structural interventions

Due to its high temporal and isotropic spatial resolution, CT has become firmly established for pre-procedural imaging in the context of structural heart disease interventions. CT allows to very exactly measure dimensions of the target structure, CT can provide information regarding the access route and, as a very valuable addition, volumetric CT data sets can be used to identify fluoroscopic projection angulations to optimally visualize the target structure and place devices. This review provides an overview of current methods and applications of pre-interventional CT to support adult cardiac interventions including transcatheter aortic valve implantation, percutaneous mitral valve intervention, left atrial appendage occlusion and paravalvular leak closure.

Clinical feasibility of catheter-directed selective intracoronary computed tomography angiography using an extremely low dose of iodine in patients with coronary artery disease

OBJECTIVE

This study aimed to evaluate the clinical feasibility of catheter-directed selective computed tomography angiography (S-CTA) in patients with coronary artery disease (CAD).

METHODS

We prospectively enrolled 65 patients diagnosed with CAD who underwent conventional computed tomography angiography (C-CTA). C-CTA was performed with 60-90 mL of contrast medium (370 mg iodine/mL), whereas S-CTA was performed with 15 mL of contrast medium and 17.19 mg iodine/mL. Luminal enhancement range, homogeneity of luminal enhancement, image quality, plaque volume (PV), and percent aggregate plaque volume (%APV) were measured. Paired Student's t test, Wilcoxon rank-sum test, and Pearson's correlation coefficient were used to compare two methods.

RESULTS

Luminal enhancement was significantly higher on S-CTA than on C-CTA (324.4 ± 8.0 Hounsfield unit (HU) vs. 312.0 ± 8.0 HU, p < 0.0001 in the per-vessel analysis). Transluminal attenuation gradient showed a significantly slower reduction pattern on S-CTA than on C-CTA (-0.65 HU/10 mm vs. -0.89 HU/10 mm, p < 0.0001 in the per-vessel analysis). Image noise was significantly lower on S-CTA than on C-CTA (39.6 ± 10.0 HU vs. 43.9 ± 9.4 HU, p < 0.0001). There was excellent correlation between S-CTA and C-CTA with respect to PV and %APV (r = 0.99, r = 0.98, respectively).

CONCLUSIONS

S-CTA might be useful in facilitating atherosclerotic plaque analysis and providing guidance for complex lesions such as chronic total occlusion, particularly in cases in which on-site procedure planning is required.

KEY POINTS

• Selective computed tomography angiography (S-CTA) can serve as an intraprocedural computed tomography angiography protocol. • S-CTA was performed with low dose of iodine compared with conventional computed tomography angiography. • S-CTA enables on-site atherosclerotic plaque analysis.

Determination of predictors of successful recanalization of the chronic occlusions of coronary arteries by means of CT-coronarography method

The review illuminated actual issues of the diagnostic efficiency of computed tomography (CT) of the coronary arteries in the planning of the procedure percutaneous coronary intervention (PCI) in patients with chronic occlusion of coronary arteries (CTO). The results of researches of detection of predictors of unsuccessful recanalization according to traditional coronary angiography (CAG) and CT angiography were presented. The major CT characteristics of the CTO, which can supplement the coronary angiography data to predict outcomes of the PCI were discussed.

A New Algorithm for Crossing Chronic Total Occlusions From the Asia Pacific Chronic Total Occlusion Club

Although the hybrid chronic total occlusion (CTO) algorithm had many excellent recommendations, there has been infrequent adoption in the Asia Pacific region. The Asia Pacific CTO club propose an algorithm for case selection based on the Japan-CTO score and a new CTO algorithm, which is applicable globally. This algorithm allows for differing skill sets and equipment availability and contains practical teaching for CTO percutaneous coronary intervention. Similar to the hybrid algorithm there are 3 main questions that determine whether the primary approach is antegrade or retrograde: 1) is there proximal cap ambiguity; 2) is the distal vessel of poor quality; and 3) are there interventional collaterals present. In contrast to the hybrid algorithm occlusion length alone does not determine the choice of either a wire escalation strategy or a dissection re-entry strategy. Rather a combination of factors including ambiguity of the vessel course, severe calcification, tortuosity, length, and previous failure are used to determine this. The role of intravascular ultrasound-guided entry to overcome proximal cap ambiguity and the CrossBoss catheter in occlusive in-stent restenosis are highlighted in the algorithm. Both the parallel wire technique and dissection re-entry with the Stingray system have been included as options when the initial antegrade wire passage fails. Intravascular ultrasound-guided wiring along with limited subintimal tracking and re-entry are included as final options in the algorithm. Finally, the algorithm incorporates guidance on when to stop the procedure. It is hoped that this algorithm will serve as the basis for future CTO percutaneous coronary intervention proctoring and training.

Diagnostic accuracy of multi-slice computed tomography in identifying lesion characteristics in coronary total occlusion

We performed this study to compare the sensitivity and specificity of multi-slice computed tomography (MSCT) to coronary angiography (CA) in detecting coronary total occlusion (CTO) lesion characteristics. Moreover, we analyzed the association between these characteristics and the risk of revascularization failure. Fifty patients with confirmed CTO diagnosis were tried for revascularization using the antegrade (all 50) or retrograde (in failed nine antegrade interventions) approaches. Each patient underwent CA and MSCT before the intervention and data from both modalities were compared using the SPSS software. Successful revascularization occurred in 36 (72%) and 6 (66.7%) patients of the antegrade and retrograde groups, respectively. Compared to CA, MSCT exhibited high sensitivity in detecting CTO segment calcification (100%), size of the affected vessel (100%, area under the curve [AUC] = 0.82), distal filling of the affected segment (97.7%) and side-branching at the CTO segment (93.3%). However, it had lower sensitivity in detecting collaterals (75%) and the length of the affected segment (87.5%, AUC = 0.77). According to MSCT data, increased occlusion length > 18 mm (p = 0.01), atherosclerotic vessel wall (p = 0.02), small distal vessel size ≤ 2.75 mm (p = 0.002), proximal side-branching (p = 0.01) and calcification of the proximal cap (p = 0.007) or distal stump (p = 0.01) were associated with an increased risk of revascularization failure. MSCT exhibited high sensitivity in identifying several CTO lesion characteristics, such as lesional calcification and size of the affected vessel. However, further research is needed to improve the diagnostic accuracy of this modality and define the predictors of revascularization failure in CTO patients.

Quantification of abdominal aortic calcification: Inherent measurement errors in current computed tomography imaging

Objective

Quantification software for coronary calcification is often used to measure abdominal aortic calcification on computed tomography (CT) images. However, there is no evidence substantiating the reliability and accuracy of these tools in this setting. Differences in coronary and abdominal CT acquisition and presence of intravascular contrast may affect the results of these tools. Therefore, this study investigates the effects of CT acquisition parameters and iodine contrast on automated quantification of aortic calcium on CT.

Methods

Calcium scores, provided in volume and mass, were assessed by automated calcium quantification software on CT scans. First, differences in calcium scores between the abdominal and coronary CT scanning protocols were assessed by imaging a thorax phantom containing calcifications of 9 metrical variations. Second, aortic calcification was quantified in 50 unenhanced and contrast-enhanced clinical abdominal CT scans at a calcification threshold of 299 Hounsfield Units (HU). Also, the lowest possible HU threshold for calcifications was calculated per individual patient and compared to a 130 HU threshold between contrast-enhanced and unenhanced CT images, respectively.

Results

No significant differences in volume and mass scores between the abdominal and the coronary CT protocol were found. However, volume and mass of all calcifications were overestimated compared to the physical volume and mass (volume range: 0–649%; mass range: 0–2619%). In comparing unenhanced versus contrast-enhanced CT images showed significant volume differences for both thresholds, as well as for mass differences for the 130 vs patient-specific threshold (230 ± 22.6 HU).

Conclusion

Calcification scoring on CT angiography tends to grossly overestimate volume and mass suggesting a low accuracy and reliability. These are reduced further by interference of intravascular contrast. Future studies applying calcium quantification tools on CT angiography imaging should acknowledge these issues and apply corrective measures to ensure the validity of their outcomes.

Feasibility and safety of augmented-reality glass for computed tomography-assisted percutaneous revascularization of coronary chronic total occlusion: A single center prospective pilot study

BACKGROUND

Percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) may be facilitated by projection of coronary computed tomography angiography (CTA) datasets in the catheterization laboratory. There is no data on the feasibility and safety outcomes of CTA-assisted CTO PCI using a wearable augmented-reality glass.

METHODS

A total of 15 patients scheduled for elective antegrade CTO intervention were prospectively enrolled and underwent preprocedural coronary CTA. Three-dimensional and curved multiplanar CT reconstructions were transmitted to a head-mounted hands-free computer worn by interventional cardiologists during CTO PCI to provide additional information on CTO tortuosity and calcification. The results of CTO PCI using a wearable computer were compared with a time-matched prospective angiographic registry of 59 patients undergoing antegrade CTO PCI without a wearable computer. Operators' satisfaction was assessed by a 5-point Likert scale.

RESULTS

Mean age was 64 ± 8 years and the mean J-CTO score was 2.1 ± 0.9 in the CTA-assisted group. The voice-activated co-registration and review of CTA images in a wearable computer during CTO PCI were feasible and highly rated by PCI operators (4.7/5 points). There were no major adverse cardiovascular events. Compared with standard CTO PCI, CTA-assisted recanalization of CTO using a wearable computer showed more frequent selection of the first-choice stiff wire (0% vs 40%, p < 0.001) and lower contrast exposure (166 ± 52 vs 134 ± 43 ml, p = 0.03). Overall CTO success rates and safety outcomes remained similar between both groups.

CONCLUSIONS

CTA-assisted CTO PCI using an augmented-reality glass is feasible and safe, and might reduce the resources required for the interventional treatment of CTO.

Coronary Computed Tomography Angiography Predicts Guidewire Crossing and Success of Percutaneous Intervention for Chronic Total Occlusion

Background—

We developed a model that predicts difficulty of percutaneous coronary intervention for coronary chronic total occlusion (CTO) using coronary computed tomographic angiography.

Methods and Results—

A total of 684 CTO lesions with preprocedural computed tomographic angiography were enrolled from 4 centers. Data were randomly divided into derivation and validation datasets at 2:1 ratio. The end point was successful guidewire crossing ≤30 minutes, which was met in 50%. The KCCT (Korean Multicenter CTO CT Registry) score was developed based on independent predictors identified by multivariable analysis, which were proximal blunt entry, proximal side branch, bending, occlusion length ≥15 mm, severe calcification, whole luminal calcification, reattempt, and ≥12 months or unknown duration of occlusion. The KCCT score was compared with the other prediction scores, including angiography-based J-CTO, PROGRESS-CTO, CL-score, and CT-based CT-RECTOR. The probability of guidewire crossing ≤30 minutes declined consistently from 100% to 0% according to the KCCT score ( P <0.01, all). The KCCT score showed higher discriminative performance compared with the other scoring systems (c-statistics=0.78 versus 0.65–0.72, P <0.001, all). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of a KCCT score of <4 for guidewire crossing ≤30 minutes was 70%, 68%, 72%, 73%, and 70%, respectively. The KCCT score also showed consistent results with procedural success ( P <0.05, all). These results could be reproduced in validation data set ( P <0.05, all).

Conclusions—

KCCT scoring could predict successful guidewire crossing ≤30 minutes and also procedural success. KCCT scoring may enable noninvasive grading difficulty of CTO percutaneous coronary intervention.

Comparison of CT-RECTOR and J-CTO scores to predict chronic total occlusion difficulty for percutaneous coronary intervention

BACKGROUND

We sought to evaluate the ability of the CT-RECTOR and J-CTO scores to predict time-efficient guidewire (GW) crossing through a chronic total occlusion (CTO) and final procedure success.

METHODS

Data from 191 consecutive CTO lesions with pre-procedural coronary computed tomography angiography (CCTA) from our center were analyzed retrospectively. The difficulty of the procedure was classified as easy, intermediate, difficult, or very difficult according to CT-RECTOR and J-CTO scores. A successful GW crossing within 30min was set as the first endpoint. Final success of the procedure was set as the second endpoint. Receiver operating characteristic curves and net reclassification improvement (NRI) were used to compare the performance of both scores in predicting both endpoints.

RESULTS

The first and second endpoints were achieved in 55% and 76% of lesions, respectively. The NRI for prediction for both endpoints were 30.21% and 28.94%, respectively. Use of the CT-RECTOR score demonstrated a positive NRI for both the first (p=0.0027) and second (p=0.0190) endpoints. Compared with the J-CTO score (area under the curve: 0.76), the CT-RECTOR score (area under the curve: 0.85) yielded a higher predictive value for successful GW crossing within 30min (p=0.0018).

CONCLUSIONS

Compared with J-CTO, the CT-RECTOR scoring system provides a more accurate noninvasive tool for predicting time-efficient GW crossing and final procedure success. This scoring system, which is based on CCTA, may aid in the identification of very difficult CTO lesions and downstream management.

Non-Iterative Rigid 2D/3D Point-Set Registration Using Semidefinite Programming

We describe a convex programming framework for pose estimation in 2D/3D point-set registration with unknown point correspondences. We give two mixed-integer nonlinear program (MINLP) formulations of the 2D/3D registration problem when there are multiple 2D images, and propose convex relaxations for both the MINLPs to semidefinite programs that can be solved efficiently by interior point methods. Our approach to the 2D/3D registration problem is non-iterative in nature as we jointly solve for pose and correspondence. Furthermore, these convex programs can readily incorporate feature descriptors of points to enhance registration results. We prove that the convex programs exactly recover the solution to the MINLPs under certain noiseless condition. We apply these formulations to the registration of 3D models of coronary vessels to their 2D projections obtained from multiple intra-operative fluoroscopic images. For this application, we experimentally corroborate the exact recovery property in the absence of noise and further demonstrate robustness of the convex programs in the presence of noise.

Usefulness of Intraprocedural Coronary Computed Tomographic Angiography During Intervention for Chronic Total Coronary Occlusion

Although intraprocedural coronary computed tomographic angiography (CCTA) allows for scanning during intervention without relocation of the patient, studies have yet to report on its use during chronic total occlusion (CTO) intervention. Therefore, we investigated the role of CCTA during CTO intervention, particularly whether CCTA could be used to evaluate the location of guidewires. A total of 61 patients scheduled for elective CTO intervention were consecutively enrolled and underwent CCTA and on-site analyses during intervention. Transverse axial and the curved multiplanar images in a 360-degree view were interactively used together to identify the location of guidewires, along with the adjustment of window condition. Intracoronary contrast injection was used for specific cases requiring enhancement of the distal part of the CTO. Most CCTAs were performed to confirm the location of a single guidewire; CCTA was also performed to evaluate parallel (3 patients) or retrograde wires (5 patients). The initial identification rate for guidewire location was 56% with immediate transaxial images, but it significantly increased to 87% after interactive on-site uses of the curved multiplanar images (p <0.001). Cases in which guidewire location could be predicted with CCTA evaluation show a numerically higher success rate than those that could not (83% vs 63%) but not statistical significance (p = 0.174). The mean time for CCTA evaluation and mean radiation dose were 8.6 minutes and 2.9 mSv, respectively. No specific complications occurred after CCTA and CTO procedures. Intraprocedural CCTA for identifying the location of the guidewires is feasible and safe when used for various CTO procedural steps.

CT Angiography for Revascularization of CTO: Crossing the Borders of Diagnosis and Treatment

Coronary computed tomography angiography (CTA) is increasingly used to diagnose and rule out coronary artery disease. Beyond stenosis detection, the ability of CTA to visualize and characterize coronary atherosclerotic plaque, as well as to obtain 3-dimensional coronary vessel trajectories, has generated considerable interest in the context of pre-procedural planning for revascularization of chronic total occlusions (CTOs). Coronary CTA can characterize features that influence the success rate of percutaneous coronary intervention (PCI) for CTOs such as the extent of calcification, vessel tortuosity, stump morphology, presence of multiple occlusions, and lesion length. Single features and combined scoring systems based on CTA may be used to grade the level of difficulty of the CTOs before PCI and have been shown to predict procedural success rates in several trials. In addition, the procedure itself may be facilitated by real-time integration of 3-dimensional CTA data and fluoroscopic images in the catheterization laboratory. Finally, the ability of coronary CTA to assess anatomy, perfusion, and viability in 1 single examination makes it a potential "one stop shop" that predicts not only the likelihood of successful PCI but also the clinical benefit of CTO revascularization. Further research is clearly needed, but many experienced sites have already integrated coronary CTA into the routine planning and guiding of CTO procedures.

Coronary Artery Disease Screening With Carotid Ultrasound Examination by a Primary Care Physician

Background

In this study, we investigated the feasibility of primary care physicians using carotid ultrasound to perform coronary artery disease screening in asymptomatic patients with multiple coronary risk factors.

Methods

We retrospectively collected the data of 135 consecutive asymptomatic patients (mean age: 68.5 ± 8.4 years; male, 75%) who were referred to our institution due to abnormal findings on a carotid ultrasound performed by a primary care physician and who underwent coronary computed tomography angiography.

Results

The mean number of risk factors was 4.1 ± 1.2 and the mean intima-media thickness was 2.00 ± 0.63 mm. Mild (≤ 50%), moderate (51-75%), and severe (> 76%) coronary stenosis was observed in 54 (40%), 27 (20%), and 25 patients (19%), respectively, while no plaque was found in 24 patients (18%), and five patients (4%) could not be evaluated due to calcification. Consequently, coronary angiography was performed in 56 (41%) patients and coronary intervention was required in 31 patients (23%). A multivariate logistic regression analysis demonstrated that the ratio of low-density lipoprotein cholesterol levels to high-density lipoprotein cholesterol levels, the use of calcium channel blockers and the value of the diastolic blood pressure were related to > 50% coronary stenosis.

Conclusions

The use of carotid ultrasound in the coronary artery disease screening by primary care physicians resulted in a high prevalence of coronary artery disease and high probabilities of coronary angiography and revascularization, and thus it is considered to be a useful and feasible strategy for the screening of asymptomatic patients.

Coronary computed tomographic prediction rule for time-efficient guidewire crossing through chronic total occlusion: insights from the CT-RECTOR multicenter registry (Computed Tomography Registry of Chronic Total Occlusion Revascularization)

OBJECTIVES

This study sought to establish a coronary computed tomography angiography prediction rule for grading chronic total occlusion (CTO) difficulty for percutaneous coronary intervention (PCI).

BACKGROUND

The uncertainty of procedural outcome remains the strongest barrier to PCI in CTO.

METHODS

Data from 4 centers involving 240 consecutive CTO lesions with pre-procedural coronary computed tomography angiography were analyzed. Successful guidewire (GW) crossing ≤30 min was set as an endpoint to eliminate operator bias. The CT-RECTOR (Computed Tomography Registry of Chronic Total Occlusion Revascularization) score was developed by assigning 1 point for each independent predictor, and then summing all points accrued. Continuous distribution of scores was used to stratify CTO into 4 difficulty groups: easy (score 0); intermediate (score 1); difficult (score 2); and very difficult (score ≥3). Discriminatory performance was tested by 10-fold cross-validation and compared with the angiographic J-CTO (Multicenter CTO Registry of Japan) score.

RESULTS

Study endpoint was achieved in 55% of cases. Multivariable analysis yielded multiple occlusions, blunt stump, severe calcification, bending, duration of CTO ≥12 months, and previously failed PCI as independent predictors for GW crossing. The probability of successful GW crossing ≤30 min for each group (from easy to very difficult) was 95%, 88%, 57%, and 22%, respectively. Areas under receiver-operator characteristic curves for the CT-RECTOR and J-CTO scores were 0.83 and 0.71, respectively (p < 0.001). Both the original model fit and 10-fold cross-validation correctly classified 77.3% of lesions.

CONCLUSIONS

The CT-RECTOR score represents a simple and accurate noninvasive tool for predicting time-efficient GW crossing that may aid in grading CTO difficulty before PCI. (Computed Tomography Angiography Prediction Score for Percutaneous Revascularization for Chronic Total Occlusions [CT-RECTOR]; NCT02022878).

Noninvasive Cardiac Imaging in Patients with Known and Suspected Coronary Artery Disease: What is in it for the Interventional Cardiologist?

The long-standing coronary artery disease (CAD) paradigm simplified by the discrimination between patients with or without CAD warrants to be revisited by the insightful information provided by noninvasive cardiac imaging, leading to a comprehensive physiopathological assessment rather than a mainly anatomical approach. This review will address (1) the role of non-invasive cardiac imaging for the appropriate selection of stable patients referred to invasive coronary angiography (ICA), and the evolving concept and prognostic implications of myocardial ischemia; (2) the usefulness of computed tomography coronary angiography for the guidance of percutaneous coronary interventions; and (3) the role and potential clinical impact of novel anatomical and functional non-invasive prognostic markers.

Role of CT Coronary Angiography in Recanalization of Chronic Total Occlusion

Chronic total occlusion (CTO) is considered as the most challenging frontier in interventional cardiology and the last one to be conquered. With availability of state of the art hardware, wires and catheters in particular and increased skills of the operators, the success rate for recanalization of CTO by percutaneous catheter intervention (PCI) has improved. Yet the complications rate and longterm adverse events are high, mostly due to failure in tracking or navigation of hardware through the occluded CTO segment, prolonged exposure to radiation and high doses of contrast used. Therefore, proper selection of patient is of utmost importance. One of the major challenges for successful CTO recanalization is satisfactory visualization of the occluded CTO segment. Conventional invasive catheterization fails to fill the gap and the shortcomings and handicaps of such invasive imaging can be resolved with the use of non-invasive CT coronary angiography (CTCA). CTCA helps to better define the morphological features of the occluded CTO segment, which are established predictors of success, like the actual length of the occluded segment and any calcification or tortuosity in its course. Integration of reconstructed three-dimensional CT coronary images with twodimensional fluoroscopic images, offers directional guide to select the best angiographic plane for visualization of angiographically “missing segment”. With advances in CT technology, CTCA has now become an established technology for pre-procedure evaluation of CTO segment, thereby help in planning and execution of successful PCI.