Optical coherence tomography-guided versus angiography-guided percutaneous coronary intervention for patients with complex lesions (OCCUPI): an investigator-initiated, multicentre, randomised, open-label, superiority trial in South Korea

Intravascular imaging for percutaneous coronary intervention on bifurcation and unprotected left main lesions: a systematic review and meta-analysis

BACKGROUND

The efficacy of intravascular imaging (IVI) guidance for percutaneous coronary intervention (PCI) represents a contemporary hot topic. PCI in patients with bifurcation coronary lesions and unprotected left main lesions offers specific challenges that, theoretically, may particularly benefit from IVI.

OBJECTIVE

To compare the clinical outcomes between IVI and angiography guidance for PCI in bifurcation and unprotected left main lesions.

METHODS

Randomised clinical trials (RCTs) comparing IVI (with either intravascular ultrasound or optical coherence tomography) with angiography to guide PCI in patients with bifurcation and unprotected left main lesions were searched in PubMed and Cochrane Central Register of Controlled Trials. Two investigators independently extracted study data. Risk ratios (RRs) were calculated using the random-effects model with inverse variance weighting and the 95% CIs with the modified Knapp-Hartung-Sidik-Jonkman method. The primary outcome was target vessel failure (TVF).

RESULTS

A total of seven RCTs were included, collecting data on 2494 patients in the analysis for bifurcation lesions and 1107 patients in the analysis for unprotected left main lesions. The mean follow-up duration ranged from 12 to 36 months. Compared with angiography guidance, IVI guidance significantly reduced TVF both in bifurcation lesions (RR 0.70, 95% CI 0.53 to 0.92) and unprotected left main lesions (RR 0.55, 95% CI 0.36 to 0.84). The number needed to treat to prevent one TVF with IVI was 27 in bifurcation lesions PCI and 11 in unprotected left main PCI.

CONCLUSION

In patients undergoing PCI on bifurcation and unprotected left main lesions, IVI guidance significantly reduces the risk of TVF compared with angiography guidance.

PROSPERO REGISTRATION NUMBER

CRD42024580321.

Advances in Clinical Cardiology 2024: A Summary of Key Clinical Trials

INTRODUCTION

In 2024, numerous key clinical trials in the field of clinical cardiology have been published or presented at major international conferences. This review seeks to collate and summarise these trials and reflect on their clinical context.

METHODS

The authors evaluated all clinical trials presented at major cardiology conferences during 2024 with a focus on clinical trials which would influence and/or change current clinical practice. We reviewed clinical trials presented at all major international conferences including the American College of Cardiology (ACC), European Association for Percutaneous Cardiovascular Interventions (EuroPCR), European Society of Cardiology (ESC), Transcatheter Cardiovascular Therapeutics (TCT), American Heart Association (AHA), European Heart Rhythm Association (EHRA), Society for Cardiovascular Angiography and Interventions (SCAI), TVT-The Heart Summit (TVT) and Cardiovascular Research Technologies (CRT). Trials considered to have highest impact and/or broad relevance across the field of clinical cardiology, with a high likelihood to change or impact upon clinical practice were included.

RESULTS

Over 90 key cardiology clinical trials were identified across the spectrum of clinical cardiology. Important updates in percutaneous coronary intervention were reviewed including new ESC guidance and several key trials in the field of coronary physiology (FAVOR III), drug-coated balloons (REGCAGE-FREE, AGENT-IDE), shock, and acute coronary syndromes (SENIOR-RITA, DanGer-Shock). Structural trials included major updates in transcatheter aortic valve replacement (TAVR) from EARLY-TAVR, TAVR-UNLOAD and NOTION 3, as well as seminal trials in tricuspid (TRISCEND II) and mitral intervention (MATTERHORN). Key updates in preventative cardiology included new data in lipoprotein (a) pharmacotherapy, low-density lipoprotein (LDL) cholesterol reduction and hypertension management (BPROAD, BedMed, KRAKEN), as well as several key trials in heart failure (SUMMIT, FINEARTS) hypertrophic cardiomyopathy (SEQUOIA-HCM) and cardiac amyloid (HELIOS-B).

CONCLUSION

The review presents a concise summary of the key clinical cardiology trials published or presented during the past year and should be of interest to clinicians and researchers in the field of cardiology.

Proportion and Clinical Impact of Stent Optimization During Imaging-Guided Percutaneous Coronary Intervention: The OCTIVUS Trial

BACKGROUND

Data regarding the proportion and clinical impact of achieving stent optimization by intravascular ultrasound (IVUS)- or optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) remain limited.

OBJECTIVES

The authors assessed the proportion and cardiovascular outcomes in patients with and without stent optimization using imaging guidance.

METHODS

This secondary analysis of the OCTIVUS (Optical Coherence Tomography-Guided or Intravascular Ultrasound-Guided Percutaneous Coronary Intervention) trial classified patients into optimized (meeting all prespecified optimization criteria) or nonoptimized groups. The primary endpoint was target vessel failure (TVF), a composite of cardiac death, target vessel myocardial infarction, or ischemia-driven target vessel revascularization.

RESULTS

Among 1,980 patients, 1,022 (51.6%) achieved stent optimization, with a lower proportion in the OCT-guided group than in the IVUS-guided group (467 of 967 [48.3%] vs 555 of 1,013 [54.8%]; P = 0.004). At a median follow-up of 2.0 years, TVF incidence was lower in the optimized group than in the nonoptimized group (39 of 1022 [3.8%] vs 72 of 958 [7.5%]; HR: 0.52; 95% CI: 0.35-0.77; P < 0.001). The effect of stent optimization on TVF appeared more substantial in OCT-guided PCI (14 of 467 [3.0%] vs 38 of 500 [7.6%]; HR: 0.39; 95% CI: 0.21-0.72) than in IVUS-guided PCI (25 of 555 [4.5%] vs 34 of 458 [7.4%]; HR: 0.63; 95% CI: 0.37-1.05), albeit there was no significant interaction between TVF and imaging modalities (P for interaction = 0.30).

CONCLUSIONS

Stent optimization was achieved in approximately one-half of patients undergoing imaging-guided PCI and was associated with a better clinical outcome. This effect appeared more pronounced in OCT-guided than in IVUS-guided PCI. (Optical Coherence Tomography Versus Intravascular Ultrasound Guided Percutaneous Coronary Intervention [OCTIVUS]; NCT03394079).

Intravascular Imaging-Guided Versus Angiography-Guided Percutaneous Coronary Intervention: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background/Objectives: Despite the potential benefits, intravascular imaging for guiding percutaneous coronary intervention (PCI) remains underutilized. Recent trials have provided new data, prompting a need for updated insights. This study aimed to perform a comprehensive meta-analysis to compare the clinical outcomes of intravascular imaging-guided PCI versus angiography-guided PCI, thereby evaluating the relative effectiveness of these two guidance strategies in improving patient outcomes. Methods: PubMed, Cochrane Library, Embase and Clinicaltrials.gov databases were systematically searched from inception till 25 November 2024. Randomized clinical trials (RCTs) comparing intravascular imaging with coronary angiography in patients undergoing complex PCI were included. Statistical analysis was conducted using a random effects model to calculate pooled risk ratios with 95% confidence intervals (CI). Results: In this meta-analysis of 21 studies involving 18,043 patients, intravascular image-guided PCI significantly reduced the risk of all-cause mortality by 24%, cardiac mortality by 63%, MACE by 35%, target vessel myocardial infarction by 32%, stent thrombosis by 42%, target vessel revascularization by 45%, target lesion revascularization by 34% and myocardial infarction by 22% compared to angiography-guided PCI. There was no significant difference in bleeding events. Conclusions: Intravascular imaging significantly reduces cardiac events, all-cause mortality and revascularization rates in PCI patients. These findings support its broader adoption and potential updates to clinical guidelines.

Optical Coherence Tomography Versus Angiography Alone to Guide PCI for Complex Lesions: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Optical coherence tomography (OCT) provides high-resolution intracoronary imaging. However, whether the addition of OCT to angiography to guide percutaneous coronary intervention (PCI) of complex lesions affects clinical outcomes is debated.

METHODS

A systematic search for randomized controlled trials was conducted using PubMed, Scopus, and Cochrane databases through September 2024. End points included major adverse cardiovascular events, cardiac death, myocardial infarction, periprocedural myocardial infarction, all-cause mortality, stent thrombosis (definite or probable), and target-vessel revascularization. The random-effects model was used to generate risk ratios (RRs) and 95% CIs.

RESULTS

A literature search identified 4 randomized controlled trials including 5603 patients with a median follow-up of 2 years. Compared with PCI guided by angiography alone, OCT-guided PCI was associated with lower major adverse cardiovascular events (RR, 0.68 [95% CI, 0.55-0.84]; P<0.001), cardiac death (RR, 0.43 [95% CI, 0.24-0.76]; P=0.003), myocardial infarction (RR, 0.75 [95% CI, 0.59-0.96]; P=0.02), all-cause mortality (RR, 0.58 [95% CI, 0.38-0.87]; P=0.009, and stent thrombosis (RR, 0.49 [95% CI, 0.26-0.90]; P=0.02). There was a trend toward lower target-vessel revascularization (RR, 0.67 [95% CI, 0.44-1.03]; P=0.07) and lower periprocedural myocardial infarction (RR, 0.79 [95% CI, 0.59-1.06]; P=0.11) with OCT guidance compared with angiography alone.

CONCLUSIONS

The addition of OCT guidance to PCI of complex lesions resulted in better clinical outcomes than angiography guidance alone. Updated guidelines should strengthen recommendations supporting the use of OCT guidance for complex PCI.

REGISTRATION

URL: https://www.crd.york.ac.uk/PROSPERO/; Unique identifier: CRD42024603847.

OCT vs Angiography for Guidance of Percutaneous Coronary Intervention of Calcified Lesions: The CALIPSO Randomized Clinical Trial

Importance

The use of intravascular imaging for calcified plaque characterization and preparation has been advocated over conventional methods to improve percutaneous coronary intervention (PCI) outcomes, but this approach has never been evaluated.

Objective

To determine if optical coherence tomography (OCT) is superior to angiography for calcified lesions PCI guidance.

Design, Setting, and Participants

The CALIPSO (Calcified Lesion Intervention Planning Steered by OCT) trial was a prospective, multicenter, open-label, randomized clinical trial that included patients with stable moderate to severe calcified coronary lesions on coronary angiography scheduled for PCI. The trial was conducted at 12 sites in France between December 2021 and June 2023, and data were analyzed from December 2023 to April 2024.

Intervention

After diagnostic coronary angiography, eligible patients were randomly assigned in a 1:1 ratio to receive OCT-guided PCI or angiography-guided PCI. In the OCT group, the procedures were guided by OCT analysis and predefined standardized management algorithms. Patients from both arms had control post-PCI OCT analysis after procedure completion for primary end point measurement.

Main Outcomes and Measures

The primary end point was the minimal stent area (MSA) measured by OCT in both groups. Secondary key safety end points included periprocedural myocardial infarction, radiation dose, contrast medium volume, and procedure duration.

Results

A total of 143 patients were randomized, and 134 were included in the final analysis (65 in the OCT group and 69 in the angiography group). Median (IQR) patient age was 73.0 (66.0-78.0) years, and 25 patients (18.7%) were female. The baseline characteristics of the groups were comparable, but the use of intravascular lithotripsy was more frequent in the OCT arm (30 patients [46%] vs 8 patients [12%]; P < .001). The final median (IQR) MSA was larger in the OCT group than in the angiography group (6.5 [5.5-8.1] mm2 vs 5.0 [4.1-6.1] mm2; P < .001). There was no difference in periprocedural complications incidence, contrast medium volume, or procedure duration between groups.

Conclusions and Relevance

The CALIPSO randomized clinical trial showed that OCT guidance associated with predefined algorithmic management achieved better stent implantation results than angiography guidance in patients with calcified lesions PCI, without any additional safety concern.

Trial Registration

ClinicalTrials.gov Identifier: NCT05301218.

Recent advances and clinical implications of intravascular imaging

Coronary artery disease (CAD) remains a major contributor to the global mortality rate. Accurate and detailed evaluation of atherosclerotic plaque characteristics is essential for effective risk assessment and treatment planning. Although conventional coronary angiography excels at quantifying luminal stenosis, information on plaque composition and structure remains limited. Recent advances in intravascular imaging (IVI) have bridged this gap by enabling high-resolution visualization of the vessel wall and plaque morphology, thereby enhancing treatment strategies and facilitating comprehensive risk stratification. Among the principal IVI modalities, intravascular ultrasound (IVUS), optical coherence tomography (OCT), and near-infrared spectroscopy (NIRS) provide distinct benefits. IVUS accurately measures vessel diameter and plaque burden, offering critical guidance for managing complex lesions and left main artery disease. The extremely high spatial resolution of OCT allows precise identification of high-risk plaque features, such as thin fibrous caps. NIRS complements these techniques by quantitatively assessing lipid components within plaques, making it particularly useful in predicting future cardiovascular events. In this review, we summarize the latest evidence on applying IVI modalities to the evaluation and treatment of CAD. We focus on the assessment of plaque morphology, identification of high-risk lesions, and the role of IVI-guided percutaneous coronary intervention (PCI). The continued development of hybrid imaging systems and artificial intelligence-based image analysis may produce more precise and safer PCI approaches. Consequently, IVI is poised to become indispensable in managing CAD, paving the way for more personalized treatment strategies tailored to the specific lesion characteristics of each patient.

Artificial intelligence for the analysis of intracoronary optical coherence tomography images: a systematic review

Intracoronary optical coherence tomography (OCT) is a valuable tool for, among others, periprocedural guidance of percutaneous coronary revascularization and the assessment of stent failure. However, manual OCT image interpretation is challenging and time-consuming, which limits widespread clinical adoption. Automated analysis of OCT frames using artificial intelligence (AI) offers a potential solution. For example, AI can be employed for automated OCT image interpretation, plaque quantification, and clinical event prediction. Many AI models for these purposes have been proposed in recent years. However, these models have not been systematically evaluated in terms of model characteristics, performances, and bias. We performed a systematic review of AI models developed for OCT analysis to evaluate the trends and performances, including a systematic evaluation of potential sources of bias in model development and evaluation.

Comparison of different guidance strategies to percutaneous coronary intervention: A network meta-analysis of randomized clinical trials

BACKGROUND

The results of randomized clinical trials comparing the outcomes of different strategies for driving PCI are mixed, and it remains unclear which technique for driving PCI offers the greatest benefit. The aim of the study was to compare the clinical efficacy of different techniques to guide percutaneous coronary intervention (PCI).

METHODS

We search major electronic databases for randomized clinical trials evaluating clinical outcomes of PCI with stent implantation guided by coronary angiography (CA), fractional flow reserve (FFR), instantaneous wave-free ratio (iFR), intravascular ultrasound (IVUS) and optical coherence tomography (OCT). The primary outcome was cardiac death.

RESULTS

The results from 39 randomized trials (29,614 patients) were included in the network meta-analyses. Compared with CA, the use of OCT (RR: 0.33, 95 % CI: 0.19-0.54), IVUS (RR: 0.47, 95 % CI: 0.31-0.71) and FFR (RR: 0.61, 95 % CI: 0.38-0.97) were associated with reduced risk of cardiac death; there were no differences between OCT, IVUS and OCT was ranked as the best strategy. PCI guidance using OCT, FFR and IVUS was also associated with a reduction of myocardial infarction. The use of OCT or IVUS for PCI guidance was associated with a significant reduction in target lesion failure, target vessel revascularization, target lesion revascularization and stent thrombosis, compared with CA. OCT-guided PCI was associated with a significant reduction in all-cause death compared with CA-guided PCI and with a reduction in TLF compared with FFR- and iFR-guided PCI. Pooled estimates were mostly consistent across several sensitivity analyses.

CONCLUSIONS

Compared with angiography-guided PCI, both an intravascular imaging-guided strategy and a physiology-guided strategy are associated with better clinical outcomes.

Efficacy and Safety of High-Frequency Optical Coherence Tomography (HF-OCT) for Coronary Imaging: A Multicenter Study

Background

Optical coherence tomography (OCT) has emerged as an essential tool in coronary atherosclerosis research and has shown clinical value in optimizing percutaneous coronary intervention. Its capability to identify coronary plaque pathology and accurately detect intervention results, often overlooked by angiography, serves as a guide in managing patients with acute coronary syndromes, myocardial infarction due to nonobstructing coronary artery disease, calcified arteries, and in-stent restenosis, thus contributing to improved clinical outcomes. However, the current technology of intracoronary imaging catheters has a size approaching 3F, limiting its adoption preintervention. Furthermore, the image field of view of current OCT technologies cannot consistently offer complete visualization of coronary arteries ≥5 mm.

Methods

In this multicenter, single-arm study, we evaluated the efficacy and safety of a novel imaging catheter and system called high-frequency optical coherence tomography (HF-OCT). This system features a reduced-size, rapid-exchange imaging catheter with a diameter of 1.8F. HF-OCT captures 100 mm long segments of coronary arteries in just 1 second. In addition, HF-OCT provides an expanded field of view greater than 14 mm in diameter, enabling complete imaging of large coronary arteries.

Results

After conducting 143 imaging acquisitions in 81 unique coronary arteries across 75 patients at 3 institutions, we obtained an average clear image length of 68.8 ± 18.8 mm. Coronary arteries of varying sizes, including cases with severe stenosis, were evaluated. Comparing preintervention HF-OCT acquisitions-taken prior to any arterial manipulation-to postintervention acquisitions, no significant difference in image quality was observed (t test, P = .901).

Conclusions

The results of this study illustrate that a lower HF-OCT catheter profile, larger field of view, and faster pullback capabilities provide reliable imaging of coronary arteries in an all-comers, multicenter population.

Artificial Intelligence-Based Fully Automated Quantitative Coronary Angiography vs Optical Coherence Tomography-Guided PCI: The FLASH Trial

BACKGROUND

Recently developed artificial intelligence-based coronary angiography (AI-QCA, fully automated) provides real-time, objective, and reproducible quantitative analysis of coronary angiography without requiring additional time or labor.

OBJECTIVES

This study aimed to evaluate the efficacy of AI-QCA-assisted percutaneous coronary intervention (PCI) compared to optical coherence tomography (OCT)-guided PCI in terms of post-PCI results.

METHODS

This trial enrolled 400 patients with significant coronary artery disease undergoing PCI from 13 participating centers in South Korea. Patients were randomized in a 1:1 ratio to either AI-QCA-assisted or OCT-guided PCI. The primary endpoint was the post-PCI minimal stent area (MSA) assessed by OCT. The noninferiority of AI-QCA-assisted PCI to OCT-guided PCI regarding the post-PCI MSA was tested with a noninferiority margin of 0.8 mm2.

RESULTS

A total of 395 patients (199 in the AI-QCA group and 196 in the OCT group) were included in the primary endpoint analysis. The post-PCI MSA was 6.3 ± 2.2 mm2 in the AI-QCA group and 6.2 ± 2.2 mm2 in the OCT group (difference, -0.16; 95% CI: -0.59 to 0.28; P for noninferiority < 0.001). Other OCT-defined endpoints, such as stent underexpansion (50.8% [101/199] vs 54.6% [107/196]; P = 0.48), dissection (15.6% [31/199] vs 12.8% [25/196]; P = 0.42), and untreated reference segment disease (15.1% [30/199] vs 13.3% [26/196]; P = 0.61), were not significantly different between groups, except for a higher incidence of stent malapposition in the AI-QCA group (13.6% [27/199] vs 5.6 [11/196]; P = 0.007).

CONCLUSIONS

This study demonstrated the noninferiority of AI-QCA-assisted PCI to OCT-guided PCI in achieving MSA with comparable OCT-defined endpoints. (Fully Automated Quantitative Coronary Angiography Versus Optical Coherence Tomography Guidance for Coronary Stent Implantation [FLASH]; NCT05388357).

Biodegradable Stents in the Treatment of Arterial Stenosis

Arterial diseases (ADs) are a significant health problem, with high mortality and morbidity rates. Endovascular interventions, such as balloon angioplasty (BA), bare-metal stents (BMSs), drug-eluting stents (DESs) and drug-coated balloons (DCBs), have made significant progress in their treatments. However, the issue has not been fully resolved, with restenosis remaining a major concern. In this context, bioresorbable vascular stents (BVSs) have emerged as a promising area of investigation. This manuscript includes articles that assess the use of BVSs. Studies have identified ongoing challenges, such as negative vascular remodeling and elastic recoil post-angioplasty, stent-related injury, and in-stent restenosis following BMS placement. While DESs have mitigated these issues to a considerable extent, their durable structures are unable to prevent late stent thrombosis and delay arterial recovery. BVSs, with their lower support strength and tendency towards thicker scaffolds, increase the risk of scaffold thrombosis. Despite inconsistent study results, the superiority of BVSs over DESs has not been demonstrated in randomized trials, and DES devices continue to be the preferred choice for most cases of arterial disease. Esprit BTK (Abbott Vascular) received approval from the US FDA for below-knee lesions in 2024, offering hope for the use of BVSs in other vascular conditions. Enhancing the design and thickness of BVS scaffolds may open up new possibilities. Large-scale and longer-term comparative studies are still required. This article aims to provide an overview of the use of biodegradable stents in the endovascular treatment of vascular stenosis.

The Role of Coronary Imaging in Chronic Total Occlusions: Applications and Future Possibilities

Chronic total occlusions (CTOs) represent a challenging scenario in coronary artery disease (CAD). The prevalence of CTOS in patients undergoing coronary angiography underscores the need for effective diagnostic and therapeutic strategies. Coronary angiography, while essential, offers limited insights into lesion morphology, vessel course, and myocardial viability. In contrast, coronary imaging techniques-including optical coherence tomography (OCT), intravascular ultrasound (IVUS), and coronary computed tomography angiography (CCTA)-provide comprehensive insights for each stage of CTO percutaneous coronary intervention (PCI). OCT facilitates the assessment of plaque morphology and stent optimization, despite low evidence and several limitations in CTO-PCI. IVUS offers deeper penetration, allowing managing proximal cap scenarios and guiding subintimal navigation. CCTA provides a non-invasive, three-dimensional view of coronary anatomy, enabling the precise evaluation of myocardial mass at risk and detailed procedural planning. Despite their individual limitations, these imaging modalities have enhanced the success rates of CTO-PCI, thus reducing procedural and long-term complications and improving patient outcomes. The future of CTO management lies in further technological advancements, including hybrid imaging, artificial intelligence (AI) integration, and improved fusion imaging. These innovations promise to refine procedural precision and personalize interventions, ultimately improving the care of patients with complex coronary artery disease.

Image-guided percutaneous revascularization of the coronary arteries

The European Society of Cardiology recently updated guidelines on the management of chronic coronary syndromes upgrading the use of intracoronary imaging for complex percutaneous coronary interventions (PCI) to a class 1A recommendation. It is essential that the interventional community appreciate the additive value of intracoronary imaging over angiography alone-not only to obtain optimal acute PCI results but also to improve longer-term cardiovascular outcomes. The purpose of this manuscript is to review the latest evidence that informed the recent guideline recommendations and expand on the specific role of the different imaging modalities before, during, and after PCI.