A New Scoring System Predicting Side-Branch Occlusion in Patients Undergoing Left Main Bifurcation Intervention: The LM V-RESOLVE Score

BACKGROUND

The risk of side-branch (SB) occlusion is pivotal for decision making of stenting strategies during unprotected left main (LM) bifurcation percutaneous coronary intervention (PCI). Accordingly, this study aimed to develop a scoring system for predicting SB occlusion during unprotected LM bifurcation PCI.

METHODS

A total of 855 consecutive patients undergoing unprotected LM bifurcation PCI with provisional strategy at Fuwai Hospital from January 2014 to December 2016 were recruited. A prediction model was selected by means of all-subsets logistic regression, and a multivariable risk score (Left Main Visual Estimation for Risk Prediction of Side Branch Occlusion in Coronary Bifurcation Intervention [LM V-RESOLVE]) was then established with incremental weights attributed to each component variable based on its estimate coefficients. SB occlusion was defined as any decrease in Thrombolysis in Myocardial Infarction (TIMI) flow grade or absence of flow in SB after main vessel (MV) stenting.

RESULTS

SB occlusion occurred in 19 LM bifurcation lesions (2.22%). In multivariable model, 3 variables, including MV/SB diameter ratio, MV plaque ipsilateral to SB, and baseline diameter stenosis of SB, were independent predictors for SB occlusion (model C-statistic 0.829, 95% confidence interval [CI] 0.735-0.923, with good calibration). The risk score had a C-statistics of 0.830 (95% CI 0.738-0.923) with good calibration. Satisfactory discriminative ability of the risk score was also preserved in external validation (C-statistic 0.794, 95% CI 0.691-0.896).

CONCLUSIONS

The LM bifurcation-specific novel scoring system, LM V-RESOLVE, based on 3 simple baseline angiographic findings, could help to rapidly discriminate lesions at risk of SB occlusion during LM bifurcation PCI.

Double Kissing Inflation Outside the Stent Versus Jailed Balloon Technique for Coronary Bifurcation Lesions

Side branch (SB) occlusion remains challenging in bifurcation percutaneous coronary intervention. We have introduced a novel method to protect SB named double kissing inflation outside the stent (DKo), which features twice inflation of protective balloon kissing with stent and postdilation balloon. This study compared protective effects of DKo vs jailed balloon technique (JBT) for bifurcation. This retrospective, single-center study enrolled 875 consecutive bifurcation lesions receiving either DKo (n = 209) or JBT (n = 666). At the 12-month follow-up, major adverse cardiac event occurred less in DKo (6.7% vs 12.0%; P = 0.042), even in 1:2 propensity score matching analysis (6.4% vs 12.3%; P = 0.034). Rewiring and transient SB loss occurred also less in DKo (0.5% vs 13.8% [P < 0.001]; 0.5% vs 4.8% [P = 0.003]). Similar results were observed in matching analysis. This study demonstrated DKo protected SB better than JBT in bifurcation percutaneous coronary intervention.

The 17th expert consensus document of the European Bifurcation Club - techniques to preserve access to the side branch during stepwise provisional stenting

Provisional stenting has become the default technique for the treatment of most coronary bifurcation lesions. However, the side branch (SB) can become compromised after main vessel (MV) stenting and restoring SB patency can be difficult in challenging anatomies. Angiographic and intracoronary imaging criteria can predict the risk of side branch closure and may encourage use of side branch protection strategies. These protective approaches provide strategies to avoid SB closure or overcome compromise following MV stenting, minimising periprocedural injury. In this article, we analyse the strategies of SB preservation discussed and developed during the most recent European Bifurcation Club (EBC) meetings.

Visually Estimated RESOLVE Score Based on Coronary Computed Tomography to Predict Side Branch Occlusion in Percutaneous Bifurcation Intervention

PURPOSE

The quantitative RESOLVE (Risk prEdiction of Side branch OccLusion in coronary bifurcation interVEntion) score derived from coronary computed tomography angiography (coronary CTA) was developed as a noninvasive and accurate prediction tool for side branch (SB) occlusion in coronary bifurcation intervention. We aimed to determine the ability of a visually estimated CTA-derived RESOLVE score (V-RESOLVE score) to predict SB occlusion in coronary bifurcation intervention.

MATERIALS AND METHODS

The present study included 363 patients with 400 bifurcation lesions. CTA-derived V-RESOLVE score was derived and compared with the quantitative CTA-derived RESOLVE score. The scoring systems were divided into quartiles, and classified as the high-risk and non-high-risk groups. SB occlusion was defined as any decrease in thrombolysis in myocardial infarction flow grade after main vessel stenting.

RESULTS

In total, 28 SB occlusions (7%) occurred. The concordance between visual and quantitative CTA analysis showed poor to excellent agreement (weighted κ range: 0.099 to 0.867). The area under the receiver operating curve for the prediction of SB occlusion was significantly higher for the CTA-derived V-RESOLVE score than for quantitative CTA-derived RESOLVE score (0.792 vs. 0.709, P=0.049). The total net reclassification index was 42.7% (P=0.006), and CTA-derived V-RESOLVE score showed similar capability to discriminate between high-risk group (18.6% vs. 13.8%, P=0.384) and non-high-risk group (3.8% vs. 4.9%, P=0.510) as compared with quantitative CTA-derived RESOLVE score.

CONCLUSIONS

Visually estimated CTA-derived V-RESOLVE score is an accurate and easy-to-use prediction tool for the stratification of SB occlusion in coronary bifurcation intervention.

Active SB-P Versus Conventional Approach to the Protection of High-Risk Side Branches: The CIT-RESOLVE Trial

OBJECTIVES

The aim of this study was to determine whether an active side branch protection (SB-P) strategy is superior to the conventional strategy in reducing side branch (SB) occlusion in high-risk bifurcation treatment.

BACKGROUND

Accurate prediction of SB occlusion after main vessel stenting followed by the use of specific strategies to prevent occlusion would be beneficial during bifurcation intervention.

METHODS

Eligible patients who had a bifurcation lesions with high risk for occlusion as determined using the validated V-RESOLVE (Visual Estimation for Risk Prediction of Side Branch Occlusion in Coronary Bifurcation Intervention) score were randomized to an active SB-P strategy group (elective 2-stent strategy for large SBs and jailed balloon technique for small SBs) or a conventional strategy group (provisional stenting for large SBs and jailed wire technique for small SBs) in a 1:1 ratio stratified by SB vessel size. The primary endpoint of SB occlusion was defined as an angiography core laboratory-assessed decrease in TIMI (Thrombolysis In Myocardial Infarction) flow grade or absence of flow in the SB immediately after full apposition of the main vessel stent to the vessel wall.

RESULTS

A total of 335 subjects at 16 sites were randomized to the SB-P group (n = 168) and conventional group (n = 167). Patients in the SB-P versus conventional strategy group had a significantly lower rate of SB occlusion (7.7% [13 of 168] vs. 18.0% [30 of 167]; risk difference: -9.1%; 95% confidence interval: -13.1% to -1.8%; p = 0.006), driven mainly by the difference in the small SB subgroup (jailed balloon technique vs. jailed wire technique: 8.1% vs. 18.5%; p = 0.01).

CONCLUSIONS

An active SB-P strategy is superior to a conventional strategy in reducing SB occlusion when treating high-risk bifurcation lesions. (Conventional Versus Intentional Strategy in Patients With High Risk Prediction of Side Branch Occlusion in Coronary Bifurcation Intervention [CIT-RESOLVE]; NCT02644434).

The impact of the extent of side branch disease on outcomes following bifurcation stenting

OBJECTIVES

To define the impact of side branch (SB) lesion length on clinical outcomes after percutaneous coronary intervention (PCI) on bifurcation lesions.

BACKGROUND

The role of the SB lesion length remains questionable in PCI planning and its implication on clinical outcome is controversial.

METHODS

Data from the retrospective multicenter EBC-P2BiTO registry were analyzed. The primary endpoint was the occurrence of major adverse cardiac events (MACE), defined as the composite of cardiac death, myocardial infarction excluding periprocedural, or stent thrombosis at 13 months median follow-up (IQR 11-28). By using propensity scores for inverse probability of treatment weighting (IPTW), the comparison of treatment groups was adjusted to correct for potential confounding.

RESULTS

Among 1,252 patients, SB was normal in 489 (39%), diseased in 763 (61%) cases. MACE occurred in 68 patients (5.4%). The optimal discriminant SB lesion length for MACE was ≥10 mm, with an area under the curve of 0.71 (p < .01). The incidence of MACE was higher among patients with SB lesions ≥10 mm (8%) than with normal SB (4.1%) (hazard ratio [HR], 2.8; 95% confidence interval [CI], 1.5-5.3; p = .001, IPTW-adjusted) or SB lesions <10 mm (5.1%) (HR, 1.5; 95% CI, 1.1-3.3; p = .048, IPTW-adjusted), being similar between these last two groups.

CONCLUSIONS

In bifurcation PCI, SB lesion length ≥ 10 mm identifies patients at higher risk of MACE than those with <10 mm SB lesions and those without SB disease, considering that no differences were observed among these last two groups. Careful planning is mandatory when approaching bifurcations with long SB lesions.

Accuracy of RESOLVE score derived from coronary computed tomography versus visual angiography to predict side branch occlusion in percutaneous bifurcation intervention

INTRODUCTION

Visually estimated angiographic V-RESOLVE score was developed as a simple and accurate prediction tool for side branch (SB) occlusion in patients undergoing coronary bifurcation intervention. Data on the use of coronary computed tomography angiography (coronary CTA) for guiding percutaneous coronary intervention in bifurcation lesions is scarce.

OBJECTIVES

We aimed to validate the ability of quantitative CTA-derived RESOLVE score for predicting SB occlusion in coronary bifurcation intervention and to compare its predictive value with that of the angiography-based V-RESOLVE score.

METHODS

We included 363 patients with 400 bifurcation lesions. Angiographic V-RESOLVE score and CTA-derived RESOLVE score were calculated utilizing the weights from the QCA-based RESOLVE score. The scoring systems were divided into quartiles, and classified as the non-high-risk group and the high-risk group. Accuracy was assessed using areas under the receiver-operator characteristic curve (AUC). SB occlusion was defined as any decrease in Thrombolysis in Myocardial Infarction flow grade (including the absence of flow) in the SB after main vessel stenting.

RESULTS

In total, 28 SB occlusions (7%) occurred. CTA-derived RESOLVE and V-RESOLVE scores achieved comparable predictive accuracy (0.709 vs. 0.752, respectively, p = 0.531) for predicting SB occlusion, and the analysis of AUC for each constituent element of the scores did not show any significant difference between CTA and visual angiography. The total net reclassification index was -18.6% (p = 0.194), and there were no significant differences in the rates of SB occlusion in the non-high-risk group (4.9% vs. 3.8%, p = 0.510) and the high-risk group (13.8% vs. 18.6%, p = 0.384) between CTA-derived RESOLVE and V-RESOLVE scores.

CONCLUSIONS

The quantitative CTA-derived RESOLVE score is an accurate and reliable alternative to the visually estimated angiographic V-RESOLVE score for prediction of SB occlusion in coronary bifurcation intervention.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT03709836.

The Relation Between Optical Coherence Tomography-Detected Layered Pattern and Acute Side Branch Occlusion after Provisional Stenting of Coronary Bifurcation Lesions

BACKGROUND/PURPOSE

Layered pattern (presumed to be healed plaque after a thrombotic event) can be observed by optical coherence tomography (OCT). We sought to assess the ability of OCT-detected plaque composition to predict acute side branch (SB) occlusion after provisional bifurcation stenting.

METHODS

This is a retrospective observational study using pre-intervention OCT in the main vessel to predict Thrombolysis in Myocardial Infarction (TIMI) flow grade ≤1 in a SB (diameter ≥ 1.5 mm) after provisional bifurcation stenting. OCT-detected layered pattern was defined as plaque with a superficial layer that had a different optical intensity and a clear demarcation from underlying tissue.

RESULTS

Overall, 207 patients with stable coronary disease were included. SB occlusion occurred in 26/207 (12.6%) bifurcation lesions. Operators decided not to perform additional treatment, and TIMI flow did not improve to ≥2 in cases with SB occlusion. The prevalence of OCT-detected layered pattern was more common in lesions with versus without SB occlusion (88.5% versus 33.7%, p < 0.0001); OCT-detected layered pattern was more often located on the same side of the SB (73.9% versus 21.3%, p < 0.0001) circumferentially compared to lesions without SB occlusion. Multivariable analysis showed that OCT-detected layered pattern was an independent predictor of SB occlusion (odds ratio 18.8, 95% confidence interval 5.1-68.8, p < 0.0001) along with true bifurcation lesion and wider angiographic bifurcation angle.

CONCLUSIONS

The presence of an OCT-detected layered pattern near its ostium was a strong predictor of SB occlusion after provisional bifurcation stenting.

Prewire channel stent: a novel stent for bifurcation lesions in a pig model

AIMS

Avoiding side branch occlusion is challenging when treating bifurcation lesions. A newly designed stent system called the prewire channel stent (PWCS) with a side channel positioned between the metallic mesh material and the balloon is introduced. We aimed to compare the time taken to position the PWCS against that for a conventional stent.

METHODS AND RESULTS

The PWCS and a conventional stent were used in a pig model. The time taken from the starting point with the stent outside the body to reaching the bifurcation of the vessel ready for further procedures such as balloon dilatation through the stent mesh opening and double kissing balloon technique, etc., was compared in the conventional stent and PWCS groups. The time taken in the PWCS stent group included the time from sending the stent from outside the body to the desired position of the bifurcation of the vessels of the heart, releasing the stent and pulling back the balloon (SB time). The time taken in the conventional stent included the time from sending the stent from outside the body to the desired position of the bifurcation of the vessels of the heart, releasing the stent, pulling back the balloon (SB time), and wire exchange (WE time). The SB times for the PWCS and the conventional stent groups were not different (28.5±3.8 vs. 25.25±0.75 seconds, n=4). The PWCS group did not have "wire exchange," and had no WE time, which was 28.5±5.7 seconds in the conventional stent group. The total time spent in the PWCS group was 28.5±3.8 seconds, which was shorter than the 53.75±6.2 seconds (n=4, p<0.05) in the conventional stent group.

CONCLUSIONS

The PWCS makes "wire exchange" in the side branch (SB) unnecessary and it can be as easily manipulated as a conventional stent.

A randomised comparison of Conventional versus Intentional straTegy in patients with high Risk prEdiction of Side branch OccLusion in coronary bifurcation interVEntion: rationale and design of the CIT-RESOLVE trial

INTRODUCTION

The intentional strategy (aggressive side branch (SB) protection strategy: elective two-stent strategy or jailed balloon technique) is thought to be associated with lower SB occlusion rate than conventional strategy (provisional two-stent strategy or jailed wire technique). However, most previous studies showed comparable outcomes between the two strategies, probably due to no risk classification of SB occlusion when enrolling patients. There is still no randomised trial compared the intentional and conventional strategy when treating bifurcation lesions with high risk of SB occlusion. We aim to investigate if intentional strategy is associated with significant reduction of SB occlusion rate compared with conventional strategy in high-risk patients.

METHODS AND ANALYSIS

The Conventional versus Intentional straTegy in patients with high Risk prEdiction of Side branch OccLusion in coronary bifurcation interVEntion (CIT-RESOLVE) is a prospective, randomised, single-blind, multicentre clinical trial comparing the rate of SB occlusion between the intentional strategy group and the conventional strategy group (positive control group) in a consecutive cohort of patients with high risk of side branch occlusion defined by V-RESOLVE score, which is a validated angiographic scoring system to evaluate the risk of SB occlusion in bifurcation intervention and used as one of the inclusion criteria to select patients with high SB occlusion risk (V-RESOLVE score ≥12). A total of 21 hospitals from 10 provinces in China participated in the present study. 566 patients meeting all inclusion/exclusion criteria are randomised to either intentional strategy group or conventional strategy group. The primary endpoint is SB occlusion (defined as any decrease in thrombolysis in myocardial infarction flow grade or absence of flow in SB after main vessel stenting). All patients are followed up for 12-month postdischarge.

ETHICS AND DISSEMINATION

The protocol has been approved by all local ethics committee. The ethics committee have approved the study protocol, evaluated the risk to benefit ratio, allowed operators with a minimum annual volume of 200 cases to participate in the percutaneous coronary intervention procedure and permitted them to perform both conventional and intentional strategies. Written informed consent would be acquired from all participants. The findings of the trial will be shared by the participant hospitals and disseminated through peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT02644434; Pre-results.