Prediction of side branch occlusions in percutaneous coronary interventions by coronary computed tomography: the CT bifurcation score as a novel tool for predicting intraprocedural side branch occlusion

Clinical outcomes of single- versus two-stent PCI technique in severely calcified true bifurcation lesions after rotational atherectomy

BACKGROUND

Severely calcified coronary bifurcations complicate percutaneous coronary interventions (PCI) and often necessitate dedicated lesion preparation. We compared the outcomes of single- versus two-stent techniques for treating heavily calcified true bifurcation lesions following rotational atherectomy (RA).

METHODS

Among patients receiving RA for severely calcified true bifurcations at a single center, 59 were treated with a single stent, and another 59 received two stents. We analyzed in-hospital adverse outcomes and 1-year rates of the bifurcation-oriented composite endpoint (BOCE), defined as cardiac death, target bifurcation myocardial infarction (TB-MI), or target bifurcation revascularization (TBR).

RESULTS

The single-stent arm was associated with more in-hospital adverse outcomes (adj. OR, 6.13; 95% CI, 1.34-28.0; p = 0.019), driven by higher peri-procedural MI rates (18.6% vs. 5.1%, p = 0.043) and more side branch compromise (13.6% vs. 0%, p = 0.006). After 1 year, both techniques had comparable 1-year BOCE (adj. HR, 0.38; 95% CI, 0.12-1.23; p = 0.106). We observed a significant interaction between the treatment technique and the presence of LM bifurcation (p interaction = 0.012), favoring single-stent technique in patients with non-LM bifurcations (HR 0.14, 95% CI 0.03-0.68; p = 0.015). Notably, the single-stent technique had lower rates of TBR (2% vs. 15%, p log-rank = 0.026) after 1 year.

CONCLUSION

Patients with severely calcified true bifurcation lesions, treated with RA followed by a single stent implantation, had more in-hospital adverse outcomes compared to those treated with two stents. However, the superior outcomes of the two-stent technique did not translate into improved long-term results. In fact, the two-stent technique was even associated with higher rates of revascularization after 1 year.

Definitions and Standardized Endpoints for Treatment of Coronary Bifurcations

The Bifurcation Academic Research Consortium (Bif-ARC) project originated from the need to overcome the paucity of standardization and comparability between studies involving bifurcation coronary lesions. This document is the result of a collaborative effort between academic research organizations and the most renowned interventional cardiology societies focused on bifurcation lesions in Europe, the United States, and Asia. This consensus provides standardized definitions for bifurcation lesions; the criteria to judge the side branch relevance; the procedural, mechanistic, and clinical endpoints for every type of bifurcation study; and the follow-up methods. Considering the complexity of bifurcation lesions and their evaluation, detailed instructions and technical aspects for site and core laboratory analysis of bifurcation lesions are also reported. The recommendations included within this consensus will facilitate pooled analyses and the effective comparison of data in the future, improving the clinical relevance of trials in bifurcation lesions, and the quality of care in this subset of patients.

A novel hybrid strategy of drug coated balloon and stent for coronary bifurcation lesions

Background. Provisional side branch (SB) stenting strategy is the default approach for the majority of bifurcation lesions, but outcomes of SB is suboptimal. Though drug coated balloon (DCB) improving SB outcomes attracts an increasing attention, sequence of DCB hasn't yet been determined. We presented a novel hybrid strategy of DCB and stent for bifurcation lesions. Methods. With lesion preparation, DCB was persistently inflated in SB kissing with main branch (MB) stent deployment and balloon post-dilation of the bifurcation core. Proximal optimization technique was performed strictly not exceeding the bifurcation. Procedural and clinical adverse events were evaluated. Canadian Cardiovascular Society (CCS) angina classification was assessed at baseline and clinical follow-up. Results. Fourteen patients undergoing the hybrid technique from August 2020 to July 2021 were enrolled. The technique was successfully performed in all patients without rewiring or SB compromise. Minimal lumen diameter of SB increased from 0.60 ± 0.40 mm to 2.1 ± 0.2 mm while the percent stenosis decreased from 72.4 ± 17.9% to 19.6 ± 4.7%. In addition, intravascular ultrasound indicated comparable stent symmetry index and incomplete stent apposition between proximal and distal segments of stent. No further intervention was performed, and mean fractional flow reserve of SB (n = 12) was 0.88 ± 0.05. No major adverse cardiac events was noted in hospital and 12-month follow up. The mean CCS angina score was reduced by 84% (2.2 vs 0.4, p < .001). Conclusion. The hybrid strategy facilitates treatment of DCB and stent for bifurcation lesions, which appears to be feasible and acceptable in a short-term follow-up.

Multislice computerized tomography coronary angiography can be a comparable tool to intravascular ultrasound in evaluating "true" coronary artery bifurcations

Aim

Coronary bifurcation atherosclerosis depends on its angles, flow, and extensive branching. We investigate the ability of CT coronary angiography (CTCA) to determine atherosclerotic plaque characteristics of "true" bifurcation compared with intravascular ultrasound (IVUS) and the influence on side branch (SB) fate after percutaneous coronary intervention (PCI).

Methods and results

The study included 70 patients with 72 "true" bifurcations. Most of the bifurcations were in the left anterior descending-diagonal (Dg) territory [50 out of 72 (69.4%)]. Longitudinal plaque evaluation at the polygon of confluence [carina and 5 mm proximal and distal in the main branch (MB)] showed that carina side MB and SB plaque had occurred with the lowest incidence with fibro-lipid structure (115 ± 63 HU and 89 ± 73 HU, p < 0.001 for all). Bland-Altman analysis showed a discrepancy in measuring mainly the lumen area between CTCA and IVUS in proximal MB [lumen 5.10, 95% CI (95% confidence interval, 4.53-5.68) mm2, p < 0.001; vessel -1.42, 95% CI (-2.63 to -0.21) mm2, p = 0.023], carina MB [lumen 3.74, 95% CI (3.37-4.10) mm2, p < 0.001; vessel -0.48, 95% CI (-1.45 to 0.48) mm2, p = 0.322], and distal MB [lumen 4.72, 95% CI (4.27-5.18) mm2, p < 0.001; vessel 0.62, 95% CI (-0.53 to 1.77) mm2, p = 0.283]. A significant correlation existed between average plaque density on CTCA with a percentage of calcified plaque on IVUS tissue characterization (proximal r = 0.307/p = 0.024, carina 0.469/0.008, distal 0.339/0.024, minimal lumen diameter 0.318/0.020). Circumferential plaque in the proximal MB segment remained an independent predictor of SB compromise [OR 3.962 (95% CI 1.170-13.418)].

Conclusion

Detection and characterization of atherosclerotic plaque by CTCA in non-left main "true" coronary bifurcations can provide useful information about bifurcation anatomy and plaque distribution that can predict outcomes after provisional stenting, thus guiding the interventional strategy to bifurcation PCI.

Pre-procedural planning of coronary revascularization by cardiac computed tomography: An expert consensus document of the Society of Cardiovascular Computed Tomography

Coronary CT angiography (CCTA) demonstrated high diagnostic accuracy for detecting coronary artery disease (CAD) and a key role in the management of patients with low-to-intermediate pretest likelihood of CAD. However, the clinical information provided by this noninvasive method is still regarded insufficient in patients with diffuse and complex CAD and for planning percutaneous coronary intervention (PCI) and surgical revascularization procedures. On the other hand, technology advancements have recently shown to improve CCTA diagnostic accuracy in patients with diffuse and calcific stenoses. Moreover, stress CT myocardial perfusion imaging (CT-MPI) and fractional flow reserve derived from CCTA (CT-FFR) have been introduced in clinical practice as new tools for evaluating the functional relevance of coronary stenoses, with the possibility to overcome the main CCTA drawback, i.e. anatomical assessment only. The potential value of CCTA to plan and guide interventional procedures lies in the wide range of information it can provide: a) detailed evaluation of plaque extension, volume and composition; b) prediction of procedural success of CTO PCI using scores derived from CCTA; c) identification of coronary lesions requiring additional techniques (e.g., atherectomy and lithotripsy) to improve stent implantation success by assessing calcium score and calcific plaque distribution; d) assessment of CCTA-derived Syntax Score and Syntax Score II, which allows to select the mode of revascularization (PCI or CABG) in patients with complex and multivessel CAD. The aim of this Consensus Document is to review and discuss the available data supporting the role of CCTA, CT-FFR and stress CT-MPI in the preprocedural and possibly intraprocedural planning and guidance of myocardial revascularization interventions.

Pre-procedural planning of coronary revascularization by cardiac computed tomography: An expert consensus document of the Society of Cardiovascular Computed Tomography

Coronary CT angiography (CCTA) demonstrated high diagnostic accuracy for detecting coronary artery disease (CAD) and a key role in the management of patients with low-to-intermediate pretest likelihood of CAD. However, the clinical information provided by this noninvasive method is still regarded insufficient in patients with diffuse and complex CAD and for planning percutaneous coronary intervention (PCI) and surgical revascularization procedures. On the other hand, technology advancements have recently shown to improve CCTA diagnostic accuracy in patients with diffuse and calcific stenoses. Moreover, stress CT myocardial perfusion imaging (CT-MPI) and fractional flow reserve derived from CCTA (CT-FFR) have been introduced in clinical practice as new tools for evaluating the functional relevance of coronary stenoses, with the possibility to overcome the main CCTA drawback, i.e. anatomical assessment only. The potential value of CCTA to plan and guide interventional procedures lies in the wide range of information it can provide: a) detailed evaluation of plaque extension, volume and composition; b) prediction of procedural success of CTO PCI using scores derived from CCTA; c) identification of coronary lesions requiring additional techniques (e.g., atherectomy and lithotripsy) to improve stent implantation success by assessing calcium score and calcific plaque distribution; d) assessment of CCTA-derived Syntax Score and Syntax Score II, which allows to select the mode of revascularization (PCI or CABG) in patients with complex and multivessel CAD. The aim of this Consensus Document is to review and discuss the available data supporting the role of CCTA, CT-FFR and stress CT-MPI in the preprocedural and possibly intraprocedural planning and guidance of myocardial revascularization interventions.

Definitions and Standardized Endpoints for Treatment of Coronary Bifurcations

The Bifurcation Academic Research Consortium (Bif-ARC) project originated from the need to overcome the paucity of standardization and comparability between studies involving bifurcation coronary lesions. This document is the result of a collaborative effort between academic research organizations and the most renowned interventional cardiology societies focused on bifurcation lesions in Europe, the United States, and Asia. This consensus provides standardized definitions for bifurcation lesions; the criteria to judge the side branch relevance; the procedural, mechanistic, and clinical endpoints for every type of bifurcation study; and the follow-up methods. Considering the complexity of bifurcation lesions and their evaluation, detailed instructions and technical aspects for site and core laboratory analysis of bifurcation lesions are also reported. The recommendations included within this consensus will facilitate pooled analyses and the effective comparison of data in the future, improving the clinical relevance of trials in bifurcation lesions, and the quality of care in this subset of patients.

A Novel Strategy to Simplify the Procedures in Treating Complicated Coronary Bifurcation Lesions: From a Bench Test to Clinical Application

Background

Although provisional stenting strategy based on jailed balloon side branch (SB) protection could be useful for high-risk bifurcation lesion in certain clinical scenarios, its complexity still gives rise to procedure complications. We proposed a novel strategy, the jailed balloon proximal optimization technique (JB-POT), to simplify the procedures in treating complex coronary bifurcation lesions (CBLs). The present study was designed to verify the safety and efficacy of JB-POT under bench testing and clinical circumstances.

Methods

After a stent was deployed in main vessel (MV) with a balloon jailed in SB, POT and post-dilation of the stent were performed without retrieving the jailed balloon. A re-POT was performed 2 mm away from SB branching point to minimize proximal stent malapposition. The JB-POT procedure was performed on 10 samples of a silicone bifurcation bench model, and optical coherence tomography (OCT) was utilized to evaluate stent deployment. From December 2018 to July 2021, a total of 28 consecutive patients with true CBLs treated with JB-POT were enrolled. Immediate procedure results were observed, and clinical follow-ups were performed.

Results

The bench test showed that JB-POT did not induce significant stent malapposition, underexpansion or distortion, as indexed by the malapposition rate, minimum stent area (MSA), eccentricity index and symmetry index determined through OCT. Under clinical circumstances, JB-POT did not induce significant malapposition, underexpansion or distortion. Among the 30 lesions, there was no primary endpoint event defined as SB occlusion, need to rewire the SB with a polymer-covered guide wire, or failure to retrieve a jailed wire or balloon. One rewiring event and 0 double stenting events occurred as secondary endpoint events. One patient died of heart failure in the 8th month after discharge.

Conclusions

The JB-POT protocol, which tremendously simplifies the current standard provisional stenting procedure in complicated bifurcation lesions, shows acceptability in safety and efficacy. Hence, it might become an applicable strategy for treating high-risk bifurcation lesions, especially those with multiple risked SBs.

Double kissing inflation outside the stent secures the patency of small side branch without rewiring

BACKGROUND

The jailed balloon technique is widely used for coronary bifurcation lesions, but a residual risk of SB occlusion remains, necessitating SB rewiring and further interventions, including balloon inflation or stenting, which may result in failure and SB loss. This study introduced a novel modified technique of small side branch (SB) protection, namely, double kissing inflation outside the stent (DKo) technique, for coronary bifurcations without the need for SB rewiring.

METHODS

We performed the DKo technique in consecutive patients in our center from 1/2019 to 12/2019. The procedure was as follows. We inserted a guide wire into both branches followed by proper preparation. The SB balloon was simultaneously inflated with main vessel (MV) stenting. The SB balloon remained in situ until it was kissing inflated with postdilation of the bifurcation core, which is different from traditional strategies. The proximal optimization technique was performed with a short noncompliant balloon strictly not exceeding the bifurcation. Rates of SB loss and in-hospital outcomes were evaluated.

RESULTS

The technique was successfully performed in all 117 enrolled patients without any rewiring or SB loss. The mean lesion lengths of the MV and SB were 38.3 ± 19.9 mm and 11.7 ± 7.1 mm, respectively. On average, 1.5 ± 0.6 stents were used per patient, while the mean pressure of the SB balloon was 7.4 ± 3.1 atm. DKo achieved excellent procedural success in the proximal and distal MVs: increased minimal lumen diameter (0.64 ± 0.58 mm to 3.05 ± 0.38 mm, p < 0.001; 0.57 ± 0.63 mm to 2.67 ± 0.35 mm, p < 0.001) and low residual stenosis (11.4 ± 3.4%; 7.2 ± 4.6%). DKo secured the patency of the SB without any rewiring and improved the SB stenosis with minimal lumen diameter (0.59 ± 0.48 mm to 1.20 ± 0.42 mm, p < 0.001) and stenosis (71.9 ± 19.4% to 42.2 ± 14.0%, p < 0.001). No MACE was noted in the hospital.

CONCLUSIONS

DKo for bifurcation lesions was shown to be acceptable with high procedural success and excellent SB protection.

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.

Impact of Lesion Preparation Technique on Side Branch Compromise in Calcified Coronary Bifurcations: A Subgroup Analysis of the PREPARE-CALC Trial

Objectives

To analyze the impact of different techniques of lesion preparation of severely calcified coronary bifurcation lesions.

Background

The impact of different techniques of lesion preparation of severely calcified coronary bifurcation lesions is poorly investigated.

Methods

We performed an as-treated analysis on 47 calcified bifurcation lesions treated with scoring/cutting balloons (SCB) and 68 lesions treated with rotational atherectomy (RA) in the PREPARE-CALC trial. Compromised side branch (SB) as assessed in the final angiogram was the primary outcome measure and was defined as any significant stenosis, dissection, or thrombolysis in myocardial infarction flow <3.

Results

True bifurcation lesions were present in 49% vs. 43% of cases in the SCB and RA groups, respectively. After stent implantation, SB balloon dilatation was necessary in around one-third of cases (36% vs. 38%; p = 0.82), and a two-stent technique was performed in 21.3% vs. 25% (p = 0.75). At the end of the procedure, the SB remained compromised in 15 lesions (32%) in the SCB group and 5 lesions (7%) in the RA group (p = 0.001). Large coronary dissections were more frequently observed in the SCB group (13% vs. 2%; p = 0.02). Postprocedural levels of cardiac biomarkers were significantly higher in patients with a compromised SB at the end of the procedure.

Conclusions

In the PREPARE-CALC trial, side branch compromise was more frequently observed after lesion preparation with SCB as compared with RA. Consequently, in calcified bifurcation lesions, an upfront debulking with an RA-based strategy might optimize the result in the side branch.

Comparison of Computed Tomography Angiography Versus Invasive Angiography to Assess Medina Classification in Coronary Bifurcations

The Medina classification is used to determine the presence of significant stenosis (≥50%) within each of the 3 arterial segments of coronary bifurcation in invasive coronary angiography (ICA). The utility of coronary computed tomography angiography (coronary CTA) for assessment of Medina classification is unknown. We aimed to compare the agreement and reproducibility of Medina classification between ICA and coronary CTA, and evaluate its ability to predict side branch (SB) occlusion following percutaneous coronary intervention (PCI). In total 363 patients with 400 bifurcations were included, and 28 (7%) SB occlusions among 26 patients were noted. Total agreement between CTA and ICA for assessment of Medina class was poor (kappa = 0.189), and discordance between both modalities was noted in 253 (63.3%) lesions. Larger diameter ratio between main vessel and SB in CTA, and larger bifurcation angle in ICA were independently associated with discordant Medina assessment. Whereas the interobserver agreement on Medina classification in CTA was moderate (kappa = 0.557), only fair agreement (kappa = 0.346) was observed for ICA. Finally, Medina class with any proximal involvement of main vessel and SB (1.X.1) on CTA or ICA was the most predictive of SB occlusion following PCI with no significant differences between both modalities (area under the curve 0.686 vs 0.663, p = 0.693, respectively). In conclusion, Medina classification was significantly affected by the imaging modality, and coronary CTA improved reproducibility of Medina classification compared with ICA. Both CTA and ICA-derived Medina class with any involvement of the proximal main vessel and SB was predictive of SB occlusion following PCI.

Noncalcified plaque burden quantified from coronary computed tomography angiography improves prediction of side branch occlusion after main vessel stenting in bifurcation lesions: results from the CT-PRECISION registry

OBJECTIVES

To assess the incremental value of quantitative plaque features measured from computed tomography angiography (CTA) for predicting side branch (SB) occlusion in coronary bifurcation intervention.

METHODS

We included 340 patients with 377 bifurcation lesions in the post hoc analysis of the CT-PRECISION registry. Each bifurcation was divided into three segments: the proximal main vessel (MV), the distal MV, and the SB. Segments with evidence of coronary plaque were analyzed using semi-automated software allowing for quantitative analysis of coronary plaque morphology and stenosis. Coronary plaque measurements included calcified and noncalcified plaque volumes, and corresponding burdens (respective plaque volumes × 100%/vessel volume), remodeling index, and stenosis.

RESULTS

SB occlusion occurred in 28 of 377 bifurcation lesions (7.5%). The presence of visually identified plaque in the SB segment, but not in the proximal and distal MV segments, was the only qualitative parameter that predicted SB occlusion with an area under the curve (AUC) of 0.792. Among quantitative plaque parameters calculated for the SB segment, the addition of noncalcified plaque burden (AUC 0.840, p = 0.003) and low-density plaque burden (AUC 0.836, p = 0.012) yielded significant improvements in predicting SB occlusion. Using receiver operating characteristic curve analysis, optimal cut-offs for noncalcified plaque burden and low-density plaque burden were > 33.6% (86% sensitivity and 78% specificity) and > 0.9% (89% sensitivity and 73% specificity), respectively.

CONCLUSIONS

CTA-derived noncalcified plaque burden, when added to the visually identified SB plaque, significantly improves the prediction of SB occlusion in coronary bifurcation intervention.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03709836 registered on October 17, 2018.

Percutaneous Coronary Intervention for Coronary Bifurcation Lesions: Latest Evidence

PURPOSE OF REVIEW

This paper provides a synopsis of the best evidence to guide bifurcation percutaneous coronary intervention (PCI), with a focus on recent studies. This is with the aim of guiding the interventional cardiologist in choosing the best, evidence-based technique, to treat commonly encountered coronary bifurcations.

RECENT FINDINGS

Current evidence supports the use of provisional stenting for most anatomically suitable bifurcation lesions. Newer techniques for side branch protection in provisional stenting have been developed. When a two-stent strategy is required, use of a double-kissing crush technique is favoured, particularly in left main bifurcations. For bifurcation PCI, as in all complex procedures, intravascular imaging plays a key adjunctive role in improving procedural success. PCI for coronary bifurcation lesions is an ever-growing field with significant advancements in techniques and technology.