Optimal Minimal Stent Area and Impact of Stent Underexpansion in Left Main Up-Front 2-Stent Strategy

Fully automated quantitative coronary angiography versus optical coherence tomography guidance for coronary stent implantation (FLASH): Study protocol for a randomized controlled noninferiority trial

BACKGROUND

Artificial intelligence-based quantitative coronary angiography (AI-QCA) has been developed to provide a more objective and reproducible data about the severity of coronary artery stenosis and the dimensions of the vessel for intervention in real-time, overcoming the limitations of significant inter- and intraobserver variability, and time-consuming nature of on-site QCA, without requiring extra time and effort. Compared with the subjective nature of visually estimated conventional CAG guidance, AI-QCA guidance provides a more practical and standardized angiography-based approach. Although the advantage of intravascular imaging-guided PCI is increasingly recognized, their broader adoption is limited by clinical and economic barriers in many catheterization laboratories.

METHODS

The FLASH (fully automated quantitative coronary angiography versus optical coherence tomography guidance for coronary stent implantation) trial is a randomized, investigator-initiated, multicenter, open-label, noninferiority trial comparing the AI-QCA-assisted PCI strategy with optical coherence tomography-guided PCI strategy in patients with significant coronary artery disease. All operators will utilize a novel, standardized AI-QCA software and PCI protocol in the AI-QCA-assisted group. A total of 400 patients will be randomized to either group at a 1:1 ratio. The primary endpoint is the minimal stent area (mm2), determined by the final OCT run after completion of PCI. Clinical follow-up and cost-effectiveness evaluations are planned at 1 month and 6 months for all patients enrolled in the study.

RESULTS

Enrollment of a total of 400 patients from the 13 participating centers in South Korea will be completed in February 2024. Follow-up of the last enrolled patients will be completed in August 2024, and primary results will be available by late 2024.

CONCLUSION

The FLASH is the first clinical trial to evaluate the feasibility of AI-QCA-assisted PCI, and will provide the clinical evidence on AI-QCA assistance in the field of coronary intervention.

CLINICAL TRIAL REGISTRATION

URL: https://www.

CLINICALTRIALS

gov. Unique identifier: NCT05388357.

Double Kissing Mini-Culotte Stenting in Unprotected Distal Left Main Bifurcation Under Optical Coherence Tomography Guidance: Immediate and Short-Term Outcomes

Culotte stenting is an effective strategy for left main coronary artery bifurcation lesions. Increased side branch ostial restenosis is the main drawback of culotte stenting. This is due to a napkin ring or potential gap produced at the ostium of the side branch. A bench study by Toth et al11 has shown that additional sequential kissing balloon dilation before main vessel stenting can prevent this deformity. We report immediate and short-term results of double kissing (DK) mini-culotte stenting with a 1-year angiographic follow-up. Between March 2020 and December 2022, 45 patients with distal left main (LM) disease underwent DK mini-culotte stenting at our center under optical coherence tomography guidance. Of 45 patients (male: 35 (77.77%); mean age: 63.67 ± 4.94 years), chronic coronary artery syndrome was present in 26 (57.8%) and unstable angina in the remainder. All lesions were Medina (1,1,1), (0,1,1), or (1,0,1), with a median Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) score of 28 (interquartile range 23 to 29). All procedures were technically successful with no adverse clinical events (death, myocardial infarction, or stent thrombosis). Under optical coherence tomography guidance, adequate minimal stent area of 13.28 ± 0.77 mm2, 8.25 ± 0.29 mm2, and 7.54 ± 0.45 mm2 was achieved in LM, left anterior descending, and left circumflex, respectively. Adequate stent expansion of >80% was achieved in all cases. At the end of 1 year, the incidence of major adverse cardiovascular events was 2.2%. Furthermore, restenosis of the side branch developed in 1 patient (2.2%), which was managed conservatively. DK mini-culotte stenting in the distal LM bifurcation has shown promising results and is effective in preventing side branch stent deformation and its sequelae of in-stent restenosis.

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.