Physiological Approach for Coronary Artery Bifurcation Disease: Position Statement by Korean, Japanese, and European Bifurcation Clubs

Development of a Novel BifurcAID Risk Score to Predict MACE Following Coronary True Bifurcation Intervention

BACKGROUND

Percutaneous coronary intervention (PCI) for true bifurcation lesions is associated with a higher risk of adverse clinical events.

OBJECTIVES

This study sought to establish a point-based score using clinical and angiographic characteristics in true bifurcation lesions before PCI to predict the risk of major adverse cardiovascular events (MACE).

METHODS

A total of 1,896 consecutive patients undergoing PCI for true bifurcation lesions between 2012 and 2019 in our institution were included. All angiograms were reviewed by an independent core laboratory for classification of the bifurcation lesions. A multivariate model identified factors associated with 1-year MACE, comprising all-cause death, myocardial infarction, and target vessel revascularization. Points were assigned to each risk factor proportional to their regression coefficients to create a cumulative risk score. The score was used to stratify patients into low-, intermediate-, and high-risk cohorts.

RESULTS

At 1-year post-PCI, MACE occurred in 185 patients (9.8%). Eleven predictors of MACE were identified: 5 clinical (insulin-dependent diabetes mellitus, left ventricular ejection fraction ≤30%, non-ST-segment elevation myocardial infarction presentation, age >80 years, and non-white race/ethnicity), and 6 angiographic (left main or left circumflex-obtuse marginal coronary artery lesion, multivessel disease, side branch [SB] thrombus, SB moderate/severe calcium, and SB lesion length >10 mm). The rate of MACE was 4.9% in low-risk patients with a risk score 0 to 6 (reference group), 12.9% in intermediate-risk patients with a score 7 to 9 (OR: 2.63; 95% CI: 1.74-3.98; P < 0.001), and 25.4% in high-risk group with a score ≥10 (OR: 5.18; 95% CI: 3.56-7.53; P < 0.001).

CONCLUSIONS

The BifurcAID risk score may facilitate risk stratification among patients undergoing true bifurcation PCI and guide patient-tailored treatment strategies.

Routine intracoronary imaging-guided left main coronary intervention

Left main (LM) percutaneous coronary intervention (PCI) with routine intracoronary imaging guidance is recommended; however, its real-world effectiveness remains unclear. A total of 743 consecutive patients undergoing drug-eluting stent implantation for de novo unprotected LM lesions across 19 Japanese National Hospital Organization hospitals where routine imaging guidance was adopted were analyzed. The primary endpoint was 1-year major adverse cardiovascular and cerebrovascular events (MACCE), comprising all-cause death, cerebrovascular disorder, clinical-driven revascularization, and myocardial infarction. In this cohort, acute coronary syndrome was present in 31.2%, with 39.3% classified as Canadian Cardiovascular Society functional angina (CCS) class ≥ III. LM bifurcation lesions were observed in 78.0%, with two-stent implantation in 8.8%. MACCE occurred in 17.5%, with target lesion revascularization and cardiac death rates of 2.0% and 3.4%, respectively. Independent risk factors for MACCE included two-stent implantation (hazard ratio [HR], 2.49), mechanical cardiac support device use (HR, 2.17), CCS class ≥ III (HR, 2.07), 10% increase in left ventricular ejection fraction (HR, 0.72), and radial access (HR, 0.62). Routine imaging-guided LM-PCI is associated with favorable low rate of target lesion revascularization and cardiac death. However, severe left ventricular dysfunction and LM bifurcation treated with two-stent implantation increase risks, requiring more comprehensive management.

State-of-the-art percutaneous coronary intervention for left main coronary artery disease in Japan

Percutaneous coronary intervention for left main coronary artery disease (LM-PCI) represents a high-risk yet life-saving procedure that has evolved significantly over the years. This review outlines the current state-of-the-art practices for LM-PCI in Japan in detail, emphasizing the integration of coronary physiology and intracoronary imaging alongside with evidence-based standardized technique using latest drug-eluting stents. These advancements enable precise lesion assessment, stent sizing, and optimal deployment, thereby enhancing procedural safety and efficacy. Despite discrepancies between current guidelines favoring coronary artery bypass grafting and real-world practice trends towards increased LM-PCI adoption, particularly in elderly populations with multiple comorbidities, careful patient selection and procedural planning are critical. Future perspectives include further refining LM-PCI through conducting randomized controlled trials integrating advanced techniques and addressing the issue of ostial left circumflex lesions and nationwide standardization of medical care for LM disease.

Left main bifurcation stenting: impact of residual ischaemia on cardiovascular mortality

AIMS

The present study sought to determine the rate and prognostic implications of post-procedural physiologically significant residual ischemia according to Murray law-based quantitative flow ratio (μQFR) after left main (LM) bifurcation percutaneous coronary intervention (PCI).

METHODS AND RESULTS

Consecutive patients undergoing LM bifurcation stenting at a large tertiary care center between January 2014 and December 2016 with available post-PCI μQFR were included. Physiologically significant residual ischemia was defined by post-PCI μQFR values ≤0.80 in the left anterior descending (LAD) or left circumflex artery (LCX). The primary outcome was 3-year cardiovascular death. The major secondary outcome was 3-year bifurcation-oriented composite endpoint (BOCE). Among 1170 included patients with analyzable post-PCI μQFR, 155 (13.2%) had residual ischemia in either LAD or LCX. Patients with vs. those without residual ischemia had a higher risk of 3-year cardiovascular mortality [5.4% vs. 1.3%; adjusted hazard ratio (HR) 3.20, 95% confidence interval (CI): 1.16-8.80]. The 3-year risk of BOCE was significantly higher in the residual ischemia group (17.8% vs. 5.8%; adjusted HR 2.79, 95% CI: 1.68-4.64), driven by higher incidence of the composite of cardiovascular death and target bifurcation-related myocardial infarction (14.0% vs. 3.3%; adjusted HR 4.06, 95% CI: 2.22-7.42). A significant, inverse association was observed between continuous post-PCI μQFR and the risk of clinical outcomes (per 0.1 μQFR decrease, HR of cardiovascular death 1.27, 95% CI: 1.00-1.62; HR of BOCE 1.29, 95% CI: 1.14-1.47).

CONCLUSION

After angiographically successful LM bifurcation PCI, residual ischemia assessed by μQFR was identified in 13.2% of patients and was associated with higher risk of 3-year cardiovascular death, indicating the superior prognostic value of post-PCI physiological assessment.

Numerical investigation of the effect of carotid bifurcation stenosis degree on pulsatility characteristics

Arterial bifurcations are regions that are susceptible to hemodynamic effects and thrombus formation. In the current study, the hemodynamic effects of a simplified 3D model of an arterial bifurcation were simulated using the commercial computational fluid dynamics software FLUENT. The non-Newtonian properties of blood were modeled using the Carreau model, and the pulsation dynamics and heat transfer characteristics of blood at different degrees of stenosis in the arterial bifurcation were analyzed. The results indicate that arterial stenosis caused by a thrombus when the pulsation velocity reaches its peak has an essential impact on blood transport. The stenosis of the bifurcation increases the peak pulsatile flow pressure drop, and each 0.5 mm stenosis of the arterial bifurcation increases the mean wall shear stress of the bifurcated segment by approximately 0.25 Pa. From the heat transfer perspective, arterial stenosis has little effect on the heat transfer coefficient. The heat transfer coefficient measured inside the bifurcation is much larger than that measured outside the bifurcation. The stenosis of the arterial bifurcation causes an increase in the mean velocity of the arterial cross-section, and the volume-averaged absolute vorticity is introduced to quantify the secondary flow effect during the pulsation cycle, where the arterial stenosis causes an increase in the mean absolute vorticity at pulsation velocity and accelerates the decay of the vorticity at uniform velocity. In this paper, the hemodynamics of carotid bifurcation pulsation is analyzed in conjunction with flow field properties to reveal the flow field dynamics factors and heat transfer characteristics of local stenosis of the carotid bifurcation and to conduct an exploratory study for the diagnosis and treatment of carotid bifurcation thrombosis.

Jailed pressure wire technique for coronary bifurcation lesions: structural damage and clinical outcomes

INTRODUCTION AND OBJECTIVES

The use of a pressure wire as a jailed wire to evaluate side branch results during provisional stenting seems feasible. However, safety concerns exist due to the mechanical damage of the wire and the lack of prospective data evaluating the prognosis of patients treated using this technique. This study sought to evaluate the structural damage of the pressure wire in patients treated using the jailed pressure wire technique and to assess mid-term clinical outcomes.

METHODS

We enrolled 99 patients with single bifurcation lesions and provisional stenting as the strategy of choice. A jailed pressure wire was used to guide side branch intervention according to the instantaneous wave-free ratio (iFR). A total of 114 patients and the respective nonpolymer-coated jailed wires were used as historical controls. Guidewire damage was evaluated by stereomicroscopy. The primary endpoint was significant microscopic damage. Major adverse cardiac events were evaluated at 2-year follow-up.

RESULTS

Significant microscopic damage was more frequent in pressure wires than in nonpolymer-coated wires (53.5% vs 22.8%, P<.001). There were no fractures in either group. There were fewer side branch interventions in the pressure wire group (postdilation/kissing balloon, 32.3% vs 56.1%, P=.001; stenting, 0.0% vs 2.6%, P=.104). The 2-year rate of major adverse cardiac events was similar between the 2 groups (HR_adj, 0.42; 95%CI, 0.10-1.73; P=.229).

CONCLUSIONS

Pressure wires were less resistant to jailing than conventional nonpolymer-coated wires. Patients treated with iFR-guided provisional stenting required fewer side branch interventions but had similar 2-year clinical outcomes than patients treated with the angiography-guided technique.

How to use three-dimensional optical coherence tomography effectively in coronary bifurcation stenting

Imaging-guided coronary bifurcation intervention has improved clinical outcomes due to the appropriate size selection of the devices and optimization of the procedure (sufficient stent expansion, reduction of stent malapposition, appropriate stent landing zone, and detection of vessel dissection). In particular, three-dimensional optical coherence tomography (3D OCT) facilitates clear visualization of stent configuration and guidewire position, which promotes optimal guidewire crossing to the side branch. Successive side branch dilation leads to wide ostial dilation with less strut malapposition. However, the link connection of the stent located on the bifurcated carina has been found to be an impediment to sufficient opening of the side branch, resulting in incomplete strut apposition. In such cases, the aggressive proximal optimization technique improves the jailing strut pattern, and 3D OCT navigates the guidewire crossing to the optimal cell that is most likely to be expanded sufficiently, which is not always a distal cell. In two-stent deployment, 3D OCT facilitates optimal guidewire crossing, which leads to less metallic carina, clustering, and overlapping. The present review describes a method of clear visualization and assessment with 3D OCT and discusses the efficacy of 3D OCT in coronary bifurcation stenting in clinical practice.

Efficacy and safety of drug-coated balloon combined with cutting balloon for side branch of true coronary bifurcation lesions: Study protocol for a multicenter, prospective, randomized controlled trial

Background

Coronary bifurcation lesions are common of percutaneous coronary intervention (PCI), and the optimal interventional therapy strategy is still a matter of debate and remains a challenge for interventional cardiologists. The provisional stenting technique is still a preferred method for most bifurcation lesions, but restenosis of the side branch (SB) occurs in approximately 17–19% of cases. Therefore, the dilemma of reducing SB restenosis still exists, and further research on strategies to reduce restenosis for SB is necessary. Drug-coated balloon (DCB) can reduce clinical events in small vessel disease and in-stent restenosis. The efficacy and safety of DCB for SB of true coronary bifurcation lesions have not been fully investigated. A randomized comparison of DCB combined with cutting balloon angioplasty vs. cutting balloon angioplasty for SB has never been published.

Methods and design

The purpose of this study is to explore the superiority of DCB combined with cutting balloon vs. cutting balloon angioplasty for SB after main vessel (MV) drug-eluting stent implantation of true coronary bifurcation lesions. This study is a multicenter, prospective, randomized controlled trial including 140 patients with true coronary bifurcation lesions. Patients will be randomized in a 1:1 manner to receive either DCB combined with cutting balloon or cutting balloon angioplasty for SB after MV drug-eluting stent implantation. The primary endpoint is the evaluation of late lumen loss (LLL) of SB at the 9-month follow-up. The secondary endpoints include procedural success during initial hospitalization, LLL of MV at the 9-month follow-up, binary angiographic restenosis in MV and SB at the 9-month follow-up, the proportion of patients with a final post-PCI quantitative flow ratio result ≤ 0.80 for SB at the 9-month follow-up, and major adverse cardiac events during the 24-month follow-up.

Conclusions

This clinical trial will provide evidence as to whether DCB combined with cutting balloon for SB of true coronary bifurcation lesions is a superior treatment approach.

Trial Registration Number

ChiCTR2000040475.

Dissemination

The results of this clinical trial will be published in a peer-reviewed journal.