AutoFOX: An automated cross-modal 3D fusion framework of coronary X-ray angiography and OCT

Coronary artery disease (CAD) is the leading cause of death globally. The 3D fusion of coronary X-ray angiography (XA) and optical coherence tomography (OCT) provides complementary information to appreciate coronary anatomy and plaque morphology. This significantly improve CAD diagnosis and prognosis by enabling precise hemodynamic and computational physiology assessments. The challenges of fusion lie in the potential misalignment caused by the foreshortening effect in XA and non-uniform acquisition of OCT pullback. Moreover, the need for reconstructions of major bifurcations is technically demanding. This paper proposed an automated 3D fusion framework AutoFOX, which consists of deep learning model TransCAN for 3D vessel alignment. The 3D vessel contours are processed as sequential data, whose features are extracted and integrated with bifurcation information to enhance alignment via a multi-task fashion. TransCAN shows the highest alignment accuracy among all methods with a mean alignment error of 0.99 ± 0.81 mm along the vascular sequence, and only 0.82 ± 0.69 mm at key anatomical positions. The proposed AutoFOX framework uniquely employs an advanced side branch lumen reconstruction algorithm to enhance the assessment of bifurcation lesions. A multi-center dataset is utilized for independent external validation, using the paired 3D coronary computer tomography angiography (CTA) as the reference standard. Novel morphological metrics are proposed to evaluate the fusion accuracy. Our experiments show that the fusion model generated by AutoFOX exhibits high morphological consistency with CTA. AutoFOX framework enables automatic and comprehensive assessment of CAD, especially for the accurate assessment of bifurcation stenosis, which is of clinical value to guiding procedure and optimization.

Intravascular lithotripsy in calcified left main coronary artery: Procedural success and 1-year clinical outcomes

BACKGROUND

Intravascular lithotripsy (IVL) has an excellent efficacy and safety profile in the treatment of calcified coronary lesions during percutaneous coronary intervention (PCI). However, data regarding its use on left main (LM) lesions are still limited.

OBJECTIVE

We aimed to analyze the technical success and 1-year clinical outcomes in calcified LM lesions treated with IVL.

METHODS

Patients who underwent IVL from the ongoing prospective BENELUX registry were eligible for inclusion. Patients were divided into LM and non-LM groups based on the anatomical application of the IVL pulses. The primary technical endpoint was technical success, defined as the successful delivery of the IVL catheter across the target lesion, administration of IVL pulses without angiographic complications, and achieving a residual target lesion stenosis of less than 30 %. The primary safety endpoint was in-hospital major adverse cardiac events (MACE).

RESULTS

The study included 509 patients (59 LM and 450 non-LM). Patients in the LM group were significantly older (79 years [75-82] vs. 73 years [68-81], p < 0.01). Left ventricular ejection fraction was slightly lower in the LM group (41 % [19-50] vs. 51 % [40-60], p = 0.053). Temporary mechanical circulatory support devices were more frequently used in the LM group, primarily as part of the "protected PCI" strategy (6.8 % in LM vs. 2.1 % in non-LM, p = 0.04). Technical success was comparable between the two groups (93.2 % in LM vs. 89.8 % in non-LM, p = 0.41). Cardiac death, MACE, and target vessel revascularization rates were also comparable at hospital discharge, 30 days, and 1-year follow-up.

CONCLUSION

IVL in calcified LM lesions achieved comparable technical success and long-term clinical outcomes to non-LM lesions.

Optical coherence tomography versus angiography to guide percutaneous coronary intervention in patients with in-stent restenosis: an observational study

BACKGROUND

Although optical coherence tomography (OCT) guidance with the 'MLDMAX' criteria is very useful for de-novo lesions during percutaneous coronary intervention (PCI), there are limited studies on its benefits in patients with in-stent restenosis (ISR). This study aimed to compare the clinical outcomes of patients with ISR who underwent repeat PCI (re-PCI) with OCT or angiographic guidance.

METHODS

This retrospective study enrolled 2142 patients with ISR who underwent re-PCI at Nanjing First Hospital from January 2016 to January 2023. The primary endpoint was the incidence of target vessel failure (TVF) post-re-PCI within 3 years. The secondary endpoints included each component of TVF.

RESULTS

After propensity score matching, 161 matched pairs were enrolled. OCT guidance of re-PCI was associated with a significantly lower risk of TVF compared with angiographic guidance alone [hazard ratio (HR), 0.51; 95% confidence interval (CI), 0.31-0.83; P  = 0.007] in patients with ISR. However, only 68.9% of patients with ISR met the final criteria of 'MLDMAX' post-re-PCI, which was associated with a lower risk of TVF compared with patients without meeting the OCT criteria (HR, 0.24; 95% CI, 0.11-0.54; P  < 0.001), and satisfied the angiographic criteria (HR, 0.40; 95% CI, 0.19-0.85; P  = 0.017).

CONCLUSION

Compared with angiographic guidance, OCT guidance significantly reduced TVF risk following re-PCI for ISR lesions, especially for patients who met the final criteria of 'MLDMAX'.

Machine Learning in Intravascular Ultrasound: Validating Automated Lesion Assessment for Complex Coronary Interventions

BACKGROUND

Intravascular ultrasound (IVUS) is essential for assessing complex coronary lesions, but remains underutilized in part due to difficulties in image interpretation. The AVVIGO IVUS Automated Lesion Assessment (ALA) software, which uses machine learning (ML) for automatic segmentation, promises to simplify lesion assessment. This study evaluated the agreement in stent size selection between ALA, an independent core laboratory (CL), and an expert interventional cardiologist (IC) for complex lesions.

AIMS

The primary endpoint was the agreement in stent size selection, within 0.25 mm, of AVVIGO ALA automatic segmentation of Class I lesions against the gold-standard measurement by an independent CL analysis and against an expert IC, (H. H.). The secondary endpoint was to assess the relative differences between AVVIGO ALA and CL, AVVIGO ALA and IC, and CL and IC, in vessel and lumen areas.

METHODS

Patients with complex coronary lesions, including left main bifurcation, long, and severely calcified lesions, were retrospectively analyzed using IVUS with ALA. Stent size selection and area measurements by ALA were compared against a CL and IC using established sizing methods.

RESULTS

In 48 patients, ALA demonstrated high agreement with CL (92%-100%) and IC (91%-98.5%) in stent size selection across lesion subtypes using recommended sizing methods. Lumen-based sizing achieved higher agreement than vessel-based sizing, particularly in calcified lesions (100% vs. 87%). The variability in relative difference in measurements between ALA and CL was greater than IC and CL in distal vessel and lesion vessel areas. The relative difference in measurements between ALA and IC was greater in vessel-based sizing compared to lumen-based sizing in the distal reference marker.

CONCLUSION

AVVIGO ALA demonstrated high agreement in stent size selection compared to a CL and expert IC. ML's ability to automate IVUS analysis may improve operator efficiency, reduce radiation exposure, and enhance the adoption of intravascular imaging in routine practice. It remains to be seen if it will impact of adoption of IVUS to guide complex PCI.

Management of Coronary Stent Underexpansion

Coronary stent underexpansion is an important problem and limitation of percutaneous coronary intervention, adversely affecting both short- and long-term patient outcomes. Stent underexpansion occurs when a stent fails to expand adequately compared with the adjacent reference segment, resulting in inadequate luminal gain. Multiple studies suggest that stent underexpansion is associated with increased risks of in-stent restenosis, stent thrombosis, and myocardial infarction, resulting in recurrent symptoms, readmissions, repeat interventions, and increased mortality. Contributing factors for stent underexpansion include severe calcification, inadequate lesion preparation, suboptimal stent deployment, and preexisting in-stent restenosis. Calcific plaques, especially when present behind a previously implanted, underexpanded stent, pose a significant challenge for further stent optimization. These lesions are often resistant to high-pressure balloon dilatation and may require advanced techniques that carry increased risks of complications. Intravascular imaging modalities, such as intravascular ultrasound and optical coherence tomography, have emerged as essential tools in diagnosing and managing stent underexpansion. These techniques provide a more detailed evaluation of the vessel and previously implanted stent, enabling the clinician to understand the exact mechanism of stent failure, and assess plaque burden and morphology, which ultimately helps guide appropriate treatment strategies. Despite the clinical importance of stent underexpansion, there is currently no consensus on its optimal treatment, largely because of the absence of large prospective studies in this area. This comprehensive review aims to summarize the existing evidence, clinical experience, and treatment strategies for coronary stent underexpansion, with the goal of providing practical guidance to clinicians to help optimize percutaneous coronary intervention and patient outcomes.

Intravascular imaging and functional assessment for coronary in-stent restenosis: Current status and future directions

Despite significant advancements in drug-eluting stent technology, in-stent restenosis (ISR) still occurs in approximately 10 % of patients undergoing percutaneous coronary intervention, remaining a significant global health concern. The mechanisms underlying ISR are complex and multifactorial, yet recent innovations in intravascular imaging and functional assessment have substantially advanced our understanding, enabling more targeted and personalized therapies. This review synthesizes the latest insights into ISR, emphasizing the pivotal roles of advanced imaging modalities, such as optical coherence tomography (OCT) and intravascular ultrasound, and functional assessments like quantitative flow ratio and optical flow ratio in guiding ISR management. Additionally, we explore the clinical implications of in-stent neoatherosclerosis and calcified nodules as key pathological mechanisms influencing restenosis progression and patient outcomes. The review also highlights the significance of OCT-based ISR classifications in refining treatment approaches. By integrating these diagnostic and therapeutic advances, this work provides clinicians and researchers with an updated foundation and actionable insights for optimizing ISR management through tailored, imaging-guided strategies.

Calcified Coronary Artery Disease: Pathology, Prevalence, Predictors and Impact on Outcomes

Calcified coronary artery disease is a common clinical finding and is visible angiographically in 25-30% of patients presenting for percutaneous coronary intervention. The presence of coronary calcium, even without coronary artery obstruction, confers an adverse clinical prognosis. Coronary calcium score on CT is additive in predicting risk of cardiovascular events beyond traditional scoring systems. Deposition of calcium in coronary arteries is initiated by the formation of an atherosclerotic plaque. Thereafter, multiple processes and pathways are involved, resulting in initial microcalcifications that coalesce into calcium sheets. Calcified nodules are thought to occur from rupture of these sheets. Calcified coronary stenoses requiring revascularisation result in greater target lesion failure and overall major adverse cardiovascular events than noncalcified lesions, regardless of the mode of revascularisation. Modifying calcium prior to stenting to optimise stent expansion is required and intracoronary imaging can greatly facilitate not only the detection of coronary calcium, but also the confirmation of adequate modification and stent optimisation. In this review, the authors examine the pathophysiology, prevalence, predictors and impact on outcomes of coronary calcium.

Assessing diagnostic accuracy of intravascular imaging for functionally significant coronary stenosis: updated findings from a meta-analysis

BACKGROUND

Accurate discrimination of functionally significant coronary stenosis using intravascular imaging remains uncertain, particularly with regard to vessel size. This meta-analysis evaluates the diagnostic performance of intravascular ultrasound (IVUS) and optical coherence tomography (OCT) for identifying functionally significant coronary stenosis as confirmed by fractional flow reserve (FFR).

METHODS

A systematic search of PubMed, Scopus and Google Scholar identified studies that assessed the diagnostic accuracy of IVUS and OCT by minimal luminal area (MLA) with FFR as the reference standard. Sensitivity and specificity were analysed across different vessel diameters including left main coronary artery (LM) lesions. Hierarchical models estimated the summary receiver operating characteristic curve, sensitivity and specificity.

RESULTS

31 studies involving 4039 patients and 4413 lesions were analysed. For IVUS, a median MLA threshold of 2.9 mm² (IQR: 2.6-3.2) predicted significant lesions, yielding an area under the curve (AUC) of 0.76. In vessels≥3 mm, this threshold increased to 3.0 mm² (IQR: 2.7-3.1) with an AUC of 0.76 while in smaller vessels it decreased to 2.6 mm² (IQR: 2.4-2.7) with an AUC of 0.79. For LM lesions, the median threshold was 6.0 mm² (IQR: 4.9-6.2) with an AUC of 0.88. OCT demonstrated a median threshold of 2.0 mm² (IQR: 1.7-2.3) and an AUC of 0.82 with better performance in larger vessels (≥3 mm, median 3.0 mm², AUC 0.87) than in smaller ones (<3 mm, median 1.8 mm², AUC 0.75).

CONCLUSIONS

IVUS and OCT show moderate diagnostic accuracy for identifying functionally significant coronary stenosis with OCT providing improved accuracy in vessels≥3 mm. IVUS is more accurate in assessing LM lesions, suggesting that vessel size should guide modality selection.

PROSPERO REGISTRATION NUMBER

CRD 42024514538.

Lesion-specific coronary artery calcium score to predict stent underexpansion

Background

Previous intracoronary imaging studies have shown that coronary artery calcium (CAC) is an independent risk factor of stent underexpansion; however, limited preintervention assessments of CAC have been performed using noninvasive methods. We aimed to determine the association between lesion-specific CAC score and stent underexpansion.

Methods

In this retrospective observational study, we included 416 lesions from 359 patients who underwent intravascular ultrasound (IVUS)-guided stent implantation. CAC of each lesion was quantified using the Agatston method derived from either nongated noncontrast chest CT (NCCT) or electrocardiogram-gated coronary CT angiography (CCTA). The primary endpoint was stent underexpansion defined as minimum stent area of <80% of the average reference lumen area.

Results

Overall, stent underexpansion occurred in 144 (34.6%) of 416 lesions. Lesion-specific CAC score was significantly negatively correlated with the stent expansion rate (in NCCT cohort, r = 0.8113, P < 0.05; in CCTA cohort, r = 0.8024, P < 0.05). The optimal cutoff values of lesion-specific CAC score to predict stent underexpansion were >200 in both NCCT (sensitivity, 91.4%; specificity, 66.8%) and CCTA (sensitivity, 84.6%; specificity, 64.3%) cohort, which were associated with 24.94-fold increased risk of stent underexpansion in NCCT cohort and 13.56-fold increased risk of stent underexpansion in CCTA cohort.

Conclusions

In this study, we found that lesion-specific CAC scores in both NCCT and CCTA cohorts were significantly independently associated with an increased risk of stent underexpansion, and the cutoff value to predict stent underexpansion was >200.

Outcomes of intravascular imaging-guided percutaneous coronary intervention according to lesion complexity

BACKGROUND

Recent trials have shown that intravascular imaging (IVI)-guided percutaneous coronary intervention (PCI) improves clinical outcome, as compared to angiography-guided PCI, in complex coronary artery lesions. However, it is unclear whether this benefit is affected by overall lesion complexity in each patient.

AIMS

The present study sought to investigate the impact of overall lesion complexity on the benefit of IVI-guided PCI.

METHODS

A total of 4,611 patients with complex coronary artery lesions from the RENOVATE-COMPLEX-PCI trial (n=1,639) and the institutional registry of the Samsung Medical Center (n=2,972) were classified according to the number of complex lesion features found in each patient. The primary outcome was target vessel failure (TVF) at 3 years, a composite of cardiac death, target vessel myocardial infarction, or target vessel revascularisation.

RESULTS

The cutoff value for the number of complex lesion features to predict TVF, determined using the maximally selected log-rank test, was 3. Patients with ≥3 complex lesion features had a higher risk of TVF than those with <3 complex lesion features (11.0% vs 7.2%, hazard ratio [HR] 1.59, 95% confidence interval [CI]: 1.28-1.96; p<0.001). IVI-guided PCI significantly reduced the risk of TVF compared with angiography-guided PCI in both groups (≥3 complex lesion features: 7.4% vs 14.4%, HR 0.49, 95% CI: 0.35-0.69; p<0.001; <3 complex lesion features: 5.7% vs 8.1%, HR 0.72, 95% CI: 0.53-0.98; p=0.039). The benefit of IVI-guided PCI tended to increase as the number of complex lesion features increased (absolute risk reduction for TVF: -0.012 vs -0.027 vs -0.055 vs -0.077, respectively, for 1 vs 2 vs 3 vs ≥4 complex lesion features; interaction p=0.048).

CONCLUSIONS

In patients with complex coronary artery lesions, IVI-guided PCI showed a lower risk of TVF across all degrees of lesion complexity. The prognostic benefit of IVI-guided PCI tended to increase as patients had more complex lesion features. (RENOVATE-COMPLEX-PCI [ClinicalTrials.gov: NCT03381872]; Institutional cardiovascular catheterisation database of the Samsung Medical Center [ClinicalTrials.gov: NCT03870815]).

The Design and Feasibility of Optimal Treatment for Coronary Drug-Eluting Stent In-Stent Restenosis (OPEN-ISR)-A Prospective, Randomised, Multicentre Clinical Trial

Introduction: Percutaneous coronary intervention (PCI) with drug-eluting stents (DES) is a cornerstone of the management of ischemic heart disease. However, in-stent restenosis (ISR) remains a significant clinical challenge, occurring in approximately 5-10% of patients undergoing PCI. This study is designed to compare the efficacy and safety of the primary therapeutic approaches for DES-ISR, specifically drug-coated balloons (DCBs)-paclitaxel-coated balloons (PCBs) and sirolimus-coated balloons (SCBs)-with a new-generation everolimus-eluting stent (EES), contributing to the evolving field of personalized medicine. Methods and Analysis: This prospective, multicentre, randomised, non-inferiority trial aims to enroll 150 patients with DES-ISR, who will be randomised into one of the following: SCB, PCB, or EES. The primary endpoint comparing DCB and EES is late lumen loss (LLL) at 6 months, as measured by quantitative coronary angiography (QCA). Secondary endpoints comparing the three arms include a device-oriented composite endpoint, intraluminal gain, optical coherence tomography (OCT) measured LLL, and correlations between LLL and quantitative flow ratio (QFR). The primary endpoint will be analysed using a non-inferiority design, with a margin set at 0.25 mm, for which the sample size was calculated. Statistical analysis of the primary endpoint will be conducted on an intention-to-treat basis with a one-tailed Mann-Whitney U test with a significance level of 95. Secondary endpoints will be analysed via superiority testing using ANOVA, the Kruskal-Wallis test, logistic regression, or Fisher's exact test, as appropriate. Ethics and Dissemination: The study protocol has been approved by the Medical Devices Department of the Hungarian National Institute of Pharmacy and Nutrition, ensuring compliance with ethical standards as outlined in the Declaration of Helsinki. All investigators declare no conflicts of interest related to this study. The trial is registered in ClinicalTrials.gov under the ID: NCT04862052.

Predicting plaque regression based on plaque characteristics identified by optical coherence tomography: A retrospective study

BACKGROUND

Atherosclerosis is a lipid-driven, systemic immune-inflammatory disease characterized by the accumulation of plaque within the arterial walls. Plaque regression can occur following appropriate treatment interventions. Optical coherence tomography (OCT), a high-resolution imaging modality, is frequently employed to assess plaque morphology. This study aims to explore the correlation between plaque characteristics identified using OCT, particularly macrophage infiltration, and subsequent plaque regression.

METHODS

In this retrospective study, data from 112 individuals with coronary artery plaques, who underwent OCT imaging at our hospital, between June 2019 and June 2024, were evaluated. Plaques were classified as lipid-rich, fibrous, or calcified based on the initial OCT findings. Macrophage infiltration levels within each plaque type were quantified. After one year of follow-up, repeat OCT imaging was performed to evaluate plaque regression. Statistical analyses were conducted to assess the relationship between initial plaque characteristics and regression outcomes.

RESULTS

Plaques that underwent regression were more commonly lipid-rich and exhibited higher levels of macrophage infiltration compared to those without regression. Multivariate analysis identified the histological inflammation score (HIS) as an independent factor influencing plaque regression.

CONCLUSION

Macrophage-rich plaques, as detected by OCT, are significant predictors of plaque regression. The identification of vulnerable plaque features through OCT can enhance the early diagnosis and treatment strategies for atherosclerotic cardiovascular disease.

Predictor of left main coronary artery size: an intravascular ultrasound study in Southeast Asia population

Left main (LM) percutaneous coronary intervention (PCI) has expanded rapidly in the past decade, with up to fourfold increase annually. Recent trials found that intravascular imaging (IVI)-guided LM PCI resulted in lower risks of cardiac death and stent failure due to suboptimal PCI compared to angiography-guided PCI. IVI usage has increased in recent years; however, its utilization remains variable across regions and is still incredibly low in developing countries. Furthermore, to date, there is no data about LM size in the Southeast Asian population. This study aims to determine the mean external elastic membrane (EEM) diameter, cross-sectional area (CSA) of LM, and its predictor. This is a cross-sectional observational study on 100 patients with coronary artery disease (CAD) who underwent IVUS-guided PCI with a pullback to LM in Dr. Hasan Sadikin General Hospital Bandung, Indonesia, from January 2020 until December 2022. Linear regression was used to determine the predictors of LM size. There were 100 segments of LM. LM's mean EEM diameter and CSA were 5.02 ± 0.43 mm and 19.93 ± 3.48 mm2. Body surface area (BSA) is an independent predictor of EEM diameter and CSA with a positive linear relationship (p 0.001 and p 0.0001). Hypertension is an independent predictor of EEM diameter with a positive linear relationship (p 0.034). The linear equation to predict EEM diameter and CSA were (2.741 + 1.272BSA(m2) + 0.165 hypertension (yes)) and (2.745 + 9.601BSA(m2)), respectively. The LM coronary artery size of the Southeast Asian population was comparable with the previous studies. BSA and hypertension are independent predictors of EEM diameter, with BSA being stronger than hypertension. Neither sex nor other cardiovascular risk factors affect the LM size. The knowledge of coronary artery size will help the clinician have a reference for intervention, especially when no intravascular imaging is available.

Intravascular Imaging Predictors Associated With Cardiovascular Events After Complex PCIs

BACKGROUND

Intravascular imaging-guided percutaneous coronary intervention (PCI) has been shown to improve clinical outcomes in patients with complex coronary artery lesions compared with angiography-guided PCI. However, the prognostic impact of suboptimal findings on intravascular imaging such as stent underexpansion, malapposition, or dissection is unclear in the era of contemporary drug-eluting stents.

METHODS

From RENOVATE-COMPLEX-PCI (Randomized Controlled Trial of Intravascular Imaging Guidance Versus Angiography-Guidance on Clinical Outcomes After Complex Percutaneous Coronary Intervention) which compared imaging-guided PCI with angiography-guided PCI in patients with complex lesions, post-PCI intravascular imaging findings, including minimum stent area (MSA), relative stent underexpansion (MSA≤80% of the average reference lumen area), malapposition, or dissection, were assessed in nonleft main target lesions. The primary end point was target lesion failure (TLF), a composite of cardiac death, target lesion-related myocardial infarction, target lesion revascularization, or definite stent thrombosis.

RESULTS

A total of 897 nonleft main lesions from 714 patients undergoing imaging-guided PCI were included. During a median follow-up duration of 2.1 years, the optimal cutoff value of MSA to predict the occurrence of TLF was 5.5 mm2, and MSA<5.5 mm2 was associated with a significantly higher risk of TLF than MSA≥5.5 mm2 (2.2% versus 4.8%; adjusted hazard ratio, 3.09 [95% CI, 1.01-9.50]; P=0.048). Compared with the reference group (MSA≥5.5 mm2 and no suboptimal findings), the subgroup of patients with MSA≥5.5 mm2 and post-PCI intravascular imaging findings of relative stent underexpansion, major malapposition, or major dissection was associated with a numerically increased risk of TLF (0.0% versus 3.2%; P=0.057). Compared with the same reference group, the subgroup of patients with MSA<5.5 mm2 and suboptimal post-PCI intravascular imaging findings was associated with a significantly increased risk of TLF (0.0% versus 4.7%; P=0.017).

CONCLUSIONS

After intravascular imaging-guided PCI with contemporary drug-eluting stents for nonleft main complex lesions, inadequate absolute stent expansion was independently associated with a higher risk of TLF. Suboptimal post-PCI intravascular imaging findings of relative stent underexpansion, major malapposition, and major dissection seem to contribute to the risk of TLF.

REGISTRATION

https://www.clinicaltrials.gov; Unique identifier: NCT03381872.

Neovascularization restructuring patterns in diabetic patients with coronary in stent restenosis: an in-vivo optical coherence tomography study

Patients with diabetes mellitus (DM) have an increased risk of in stent restenosis (ISR). Neovascularization (NV) is considered as a unique pathophysiology factor of ISR in diabetic patients. However, the restructuring patterns of in vivo human coronary NV and their relationship with ISR, especially in diabetic patients remain unclear. In this study, we aimed to investigate the NV structure differentiations between patients with and without DM after coronary stent implantation using optical coherence tomography (OCT). We included 136 patients with ISR (70 patients in DM group and 66 patients in non-DM group) who underwent OCT during coronary angiography follow-up. NVs were manually segmented, after which three-dimensional (3D) rendering of OCT images was conducted. NVs greater than 1 mm in length were classified as longitudinal running or coral tree types based on their 3D structures. NV structures were compared between DM and non-DM patients. The prevalence of the coral tree pattern NV in the DM group was 2.14-fold higher than in the non-DM group(p = 0.012). 47.14% of patients in the DM group and 51.51% of patients in the non-DM group presented longitudinal running NV (p = 0.610). The number of coral tree pattern NV was relatively higher in DM patients than in the non-DM patients (p = 0.019). However, the number of longitudinal running NV showed no difference between the two groups (p = 0.872). The normalized NV volume was significantly larger in the DM group (p = 0.008). Patients with coral tree pattern NV have thinner minimum fibrous cap thickness (p = 0.030). DM was the risk factor for coral tree pattern NV formation in ISR lesions after adjustment for other factors. NV with specific restructuring patterns, such as longitudinal running and coral tree patterns, can be identified in ISR lesions. NV with a coral tree pattern, characterized by higher leakiness and immaturity, is more commonly found in patients with DM and is associated with tissue instability in ISR. Accurate and feasible imaging modalities for NV might offer promising opportunities to evaluate NV and prevent progression of ISR in diabetic patients.

Stent Crumpling as a Complication of Percutaneous Coronary Intervention, a Case Report and Literature Review

Stent crumpling is a rare but potentially life-threatening complication of percutaneous coronary intervention (PCI). This report highlights a case of stent crumpling during a PCI procedure, its management, and the importance of advanced imaging techniques in diagnosing and addressing such complications. A 78-year-old man was admitted for elective PCI on the left anterior descending (LAD) artery following an acute anterior ST-segment elevation myocardial infarction (STEMI) treated with thrombolytic therapy. The patient exhibited significant ischemic changes on his electrocardiogram (ECG) and experienced persistent angina. During the PCI, two overlapping stents were deployed in the LAD. Post-dilation led to slow flow and thrombus formation in the LAD, rapidly progressing to cardiac arrest. Immediate resuscitation and intracoronary thrombolytic therapy were initiated. Intravascular ultrasound (IVUS) revealed stent crumpling, so the proximal stent folded within the vessel lumen. To solve this issue, the crumpled stent was crushed behind a newly deployed stent, followed by post-dilation, which restored TIMI flow grade III in the LAD.

OUFR Versus FFR for Functional Assessment of Coronary Artery Stenosis in Patients With Unstable Angina

BACKGROUND

Hybrid intravascular ultrasound-optical coherence tomography (IVUS-OCT) imaging can integrate both advantages. Optical ultrasonic flow ratio (OUFR) was recently developed for functional assessment.

OBJECTIVES

This study aimed to verify the diagnostic performance of OUFR using fractional flow reserve (FFR) as the reference standard.

METHODS

From February 2023 to June 2023, 80 patients (126 vessels) with unstable angina pectoris were assessed with FFR and either hybrid IVUS-OCT or stand-alone IVUS imaging before percutaneous coronary intervention in a prospective series. OUFR based on OCT alone (OUFRO) or based on both (OUFROI) were derived from hybrid IVUS-OCT imaging in 61 patients (86 vessels). OUFR based on IVUS alone (OUFRI) was derived from single modality IVUS imaging in 58 patients (80 vessels). In all cases, wire-based FFR was measured in the same vessels for comparison.

RESULTS

All 3 computed OUFR indexes achieved high agreement with FFR, with OUFROI and OUFRO showing higher correlation with FFR (r = 0.88; P < 0.001; r = 0.85; P < 0.001, respectively) than OUFRI (r = 0.73; P < 0.001). Compared with OUFRO, the integration of both IVUS and OCT (OUFROI) further improved the diagnostic accuracy for predicting FFR ≤0.80 with accuracy, sensitivity, and specificity being 95%, 94%, and 96%, respectively. The area under the curve of OUFROI to predict FFR ≤0.80 was 0.99, higher than that for OUFRO (0.95) and OUFRI (0.91).

CONCLUSIONS

OUFROI is feasible and accurate in the prospective study, resulting in excellent agreement with FFR, superior to single imaging modality-based physiology indexes.

Intravascular Imaging as a Performance Measure for Percutaneous Coronary Intervention

BACKGROUND

Intravascular imaging (IVI) is widely recognized to improve outcomes after percutaneous coronary intervention (PCI). However, IVI is underutilized and is not yet established as a performance measure for quality PCI.

METHODS

We examined temporal trends of IVI use for all PCIs performed at Veterans Affairs hospitals in the United States from 2010 to 2022 using retrospective observational cohorts. IVI was defined as intravascular ultrasound or optical coherence tomography. A contemporary subset of PCIs from 2020 to 2022 was used to examine clinical characteristics associated with IVI use and test the reliability of IVI as a pass/fail performance measure. We then used a generalized linear mixed model to estimate the proportion of IVI use variability attributable to the hospital, physician, and patient level. Cox proportional hazard models were used to assess the association of IVI with clinical outcomes at 1 year.

RESULTS

IVI use increased from 12.3% in 2010 to 43.1% in 2022 in 136 071 PCIs included in the study. Among 22 918 PCIs in the contemporary cohort, IVI was more frequent with nonemergent presentations, chronic total occlusions, and left main lesions but usage variability was primarily attributable to hospital (54%) and physician (33%) levels. As a pass/fail performance measure, reliability was high (>0.96) at hospital and physician levels. However, IVI use was not associated with statistically significant differences in mortality or major adverse cardiovascular events in this cohort.

CONCLUSIONS

IVI use for PCI is increasing rapidly at Veterans Affairs hospitals in the United States but with marked variation at the hospital and physician levels. IVI meets established criteria for an effective performance measure and should be measured and reported by local and national organizations to encourage further uptake. Ongoing training and quality improvement may be required to maximize the benefit of IVI as it is more widely utilized.

Evaluating the Influence of Morphological Features on the Vulnerability of Lipid-Rich Plaques During Stenting

Lipid-rich atheromas are linked to plaque rupture in stented atherosclerotic arteries. While fibrous cap thickness is acknowledged as a critical indicator of vulnerability, it is likely that other morphological features also exert influence. However, detailed quantifications of their contributions and intertwined effects in stenting are lacking. Therefore, our goal is to assess the impact of plaque characteristics on the fibrous cap stress and elucidate their underlying mechanisms. We analyzed the stent deployment in a three-dimensional patient-specific coronary artery reconstructed from intravascular optical coherence tomography (IVOCT) data using the finite element method. Additionally, we performed sensitivity analysis on 78,000 distinct plaque geometries of two-dimensional arterial cross section for verification. Results from the three-dimensional patient-specific model indicate strong correlations between maximum fibrous cap stress and lipid arc (r=0.769), area stenosis (r=0.550), and lumen curvature (r=0.642). Plaques with lipid arcs >60 deg, area stenosis >75%, and lumen curvatures >5 mm-1 are at rupture risk. While we observed a rise in stress with thicker lipid cores, it was less representative than other features. Fibrous cap thickness showed a poor correlation, with the sensitivity analysis revealing its significance only when high stretches are induced by other features, likely due to its J-shaped stress-stretch response. Contrary to physiological pressure, the stent expansion generates unique vulnerable features as the stent load-transferring characteristics modify the plaque's response. This study is expected to prompt further clinical investigations of other morphological features for predicting plaque rupture in stenting.

CVIT 2025 clinical expert consensus document on intravascular ultrasound

Intravascular ultrasound (IVUS) provides precise anatomic information in coronary arteries including quantitative measurements and morphological assessment. To standardize the IVUS analysis in the current era, this updated expert consensus document summarizes the methods of measurements and assessment of IVUS images and the clinical evidence of IVUS use in percutaneous coronary intervention.

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).

Long-term outcomes of second-generation drug-eluting stents versus coronary artery bypass graft: a systematic review and meta-analysis of randomized trials and multivariable adjusted data

Long-term data are limited comparing percutaneous coronary intervention (PCI) with second-generation drug-eluting stents (S-DES) vs coronary artery bypass grafting (CABG) in patients with complex coronary artery disease (CAD). We aimed to conduct a systematic review and meta-analysis comparing these interventions in patients with left main or multivessel CAD. We systematically reviewed PubMed, Embase, and Cochrane for studies that compared PCI with S-DES and CABG in patients with left main or multivessel CAD with a minimum mean follow-up period of 3 years. Outcomes of interest were all-cause mortality, myocardial infarction (MI), stroke, and major adverse cardiovascular events (MACE). We extracted data from observational studies as multivariable-adjusted or propensity score-matched hazard ratio to minimize confounding and pooled hazard ratios with 95% confidence intervals (CIs) using a random effects model in Review Manager 5.4.1. We included 10 studies, 3 of which were randomized controlled trials, comprising a total of 26964 patients, of whom 14928 underwent PCI. As compared with CABG, S-DES had a significantly higher risk of all-cause mortality (hazard ratio 1.35; 95% CI 1.22-1.49; P < 0.001; I2 = 0%), MACE (hazard ratio 1.27; 95% CI 1.08-1.50; P = 0.005; I2 = 67%), and MI (hazard ratio 2.43; 95% CI 1.80-3.28; P < 0.01; I2 = 0%). There was no significant difference between groups in incidence of stroke. In this meta-analysis of patients with complex CAD, PCI with S-DES was associated with an increased risk of mortality, MI, and MACE compared with CABG.

Effect of Intravascular Ultrasonography (IVUS) Imaging on Stent Optimization in Patients Achieving Optimal Results After Angiographic-Guided Stent Implantation: A Non-randomized Interventional Study

BACKGROUND

Angiography possesses limitations in assessing plaque composition, vessel width, diffuse reference vessel disease, lesion severity, and the success or failure of stent placement. Intravascular ultrasonography (IVUS) helps address several of these issues by offering enhanced visualization of the coronary architecture and stent placement.

METHODS

This study was conducted at the Department of Cardiology of All India Institute of Medical Sciences, Rishikesh. It spanned 12 months with a six-month follow-up and involved post-angiography-guided angioplasty and stenting. All patients underwent IVUS pullback. Due to the non-working of the unspecified surgical package under the Ayushman Bharat scheme, the study included 16 patients, with an intended target of 30 patients.

RESULTS

Half of the patients (eight, 50%) presented with acute coronary syndrome, while the other half presented with chronic stable angina. Left main coronary artery disease was present in 50% of patients, and 13 (81.25%) had complex coronary artery lesions. After angiography-guided angioplasty, IVUS pullback on all patients revealed that only three patients (18.75%) required post-IVUS optimization of the stent.

CONCLUSION

The majority of patients did not require post-IVUS optimization following angiography-guided angioplasty and stenting. No major adverse cardiovascular events were recorded, and no target vessel myocardial infarction (MI), target vessel revascularization, target lesion revascularization, or stent thrombosis (ST) were reported over the six-month follow-up period.

Predictive models for cholesterol crystals and plaque vulnerability in acute myocardial infarction: Insights from an optical coherence tomography study

BACKGROUND

Cholesterol crystals (CCs) are recognized as a risk factor for vulnerable atherosclerotic plaque rupture (PR) and major adverse cardiovascular events. However, their predictive factors and association with plaque vulnerability in patients with acute myocardial infarction (AMI) remain insufficiently explored. Therefore, This study aims to investigate the association between CCs and plaque vulnerability in culprit lesions of AMI patients, identify the factors influencing CCs formation, and develop a predictive model for CCs.

METHODS

A total of 431 culprit lesions from AMI patients who underwent pre-intervention optical coherence tomography (OCT) imaging were analyzed. Patients were divided into groups based on the presence or absence of CCs and PR. The relationship between CCs and plaque vulnerability was evaluated. A risk nomogram for predicting CCs was developed using the least absolute shrinkage and selection operator and logistic regression analysis.

RESULTS

CCs were identified in 64.5 % of patients with AMI. The presence of CCs was associated with a higher prevalence of vulnerable plaque features, such as thin-cap fibroatheroma (TCFA), PR, macrophage infiltration, neovascularization, calcification, and thrombus, compared to patients without CCs. The CCs model demonstrated an area under the curve (AUC) of 0.676 for predicting PR. Incorporating CCs into the TCFA model (AUC = 0.656) significantly enhanced predictive accuracy, with a net reclassification improvement index of 0.462 (95 % confidence interval [CI]: 0.263-0.661, p < 0.001) and an integrated discrimination improvement index of 0.031 (95 % CI: 0.013-0.048, p = 0.001). Multivariate regression analysis identified the atherogenic index of plasma (odds ratio [OR] = 2.417), TCFA (OR = 1.759), macrophage infiltration (OR = 3.863), neovascularization (OR = 2.697), calcification (OR = 1.860), and thrombus (OR = 2.430) as independent risk factors for CCs formation. The comprehensive model incorporating these factors exhibited reasonable discriminatory ability, with an AUC of 0.766 (95 % CI: 0.717-0.815) in the training set and 0.753 (95 % CI: 0.704-0.802) in the internal validation set, reflecting good calibration. Decision curve analysis suggested that the model has potential clinical utility within a threshold probability range of approximately 18 % to 85 %.

CONCLUSIONS

CCs were associated with plaque vulnerability in the culprit lesions of AMI patients. Additionally, this study identified key factors influencing CCs formation and developed a predictive model with potential clinical applicability.

Value of Combined Optical Coherence Tomography and Optical Flow Ratio Measurements After Percutaneous Coronary Intervention

BACKGROUND

Optical flow ratio (OFR) is a novel computational fractional flow reserve derived from optical coherence tomography (OCT). However, the impact of combining post-stenting morphology (OCT) and physiology (OFR) remains largely unknown.

METHODS

OCT and OFR were analysed at an independent core laboratory. Target lesion failure (TLF) was defined as the composite of cardiac death, target lesion myocardial infarction, and target lesion revascularisation. Suboptimal stent deployment was identified with at least 1 TLF-related OCT or OFR characteristic.

RESULTS

A total of 448 patients with acute coronary syndrome (459 vessels) were assessed. Stent expansion < 80%, minimal stent area < 4.5 mm2, stent edge lipid-rich plaque and OFR < 0.90 were independent predictors of TLF (all P < 0.001). Patients with OCT-suboptimal (adjusted hazard ratio [aHR] 7.88, 95% CI 2.73-22.72,-P < 0.001) or OFR-suboptimal (aHR 5.78, 95% CI 2.54-13.14; P < 0.001) stent deployment showed significantly higher risk of TLF compared with those with optimal stent deployment, with a significant interaction (Pinteraction < 0.001). OCT and OFR both-suboptimal stent deployment was confirmed as an independent predictor of TLF (aHR 9.39, 95% CI 4.25-20.76; P < 0.001).

CONCLUSIONS

Combined OCT and OFR conferred an optimal reclassification of stent deployment, which may aid in decision making regarding a tailored PCI strategy for optimal stent deployment.

The Effect of Intravascular Imaging-Guided Percutaneous Coronary Intervention on Coronary Artery Perforation

Background

Intravascular imaging (IVI) complements coronary angiography and may help prevent coronary artery perforation (CAP) during percutaneous coronary intervention (PCI).

Objectives

The authors evaluated whether IVI-guided PCI is associated with a lower risk of PCI-related CAP in a real-world cohort.

Methods

This observational study analyzed consecutive PCI procedures from January 2006 to October 2023. The procedures were divided into 4 groups according to the year performed: 2006 to 2010 (P1), 2011 to 2015 (P2), 2016 to 2020 (P3), and 2021 to 2023 (P4). We evaluated the trend of IVI-guided PCI and the incidence of CAP. A mixed effects logistic model was employed to assess their relationship.

Results

CAP occurred in 368 (1.6%) of 22,368 PCIs. IVI-guided PCI accounted for 63% of all cases, of which 95% were intravascular ultrasound procedures. From P1 to P3, the ratio of IVI-guided PCI increased linearly (P1: 30%, P2: 61%, P3: 93%, P4: 97%), while the incidence of CAP decreased (P1: 2.10%, P2: 1.74%, P3: 1.13%, P4: 1.18%). IVI-guided PCI showed a significant association with a lower risk of the overall incidence of CAP (adjusted OR: 0.78; 95% CI: 0.61-0.99; P = 0.047). This relationship was particularly significant for chronic total occlusion PCI (adjusted OR: 0.59; 95% CI: 0.43-0.80; P = 0.001) and PCI for moderate or severe calcification (adjusted OR: 0.50; 95% CI: 0.33-0.74; P = 0.001).

Conclusions

IVI-guided PCI may help prevent PCI-related CAP, especially in the setting of chronic total occlusion PCI and PCI for moderate or severe calcification.

Intravascular Imaging-Guided Percutaneous Coronary Intervention in Patients With End-Stage Renal Disease on Maintenance Dialysis

Background

Patients with end-stage renal disease (ESRD) are at a higher risk of cardiovascular diseases. Intravascular imaging (IVI)-guided percutaneous coronary intervention (PCI) using optical coherence tomography (OCT) or intravascular ultrasound (IVUS) has been shown to result in better clinical outcomes than angiography guidance. Nevertheless, the clinical outcomes of IVI-guided PCI in ESRD patients remain uncertain.

Objectives

This study aimed to compare the clinical outcomes of OCT- and IVUS-guided PCIs in ESRD patients and to report the trend of IVI-guided PCI in Taiwan.

Methods

Patients with ESRD on maintenance dialysis, who underwent OCT- or IVUS-guided PCI from 2015 to 2021, were compared by propensity-score matching. The primary outcome was composite cardiovascular outcomes, including coronary revascularization, cardiovascular death, and acute myocardial infarction.

Results

In 2021, IVI was used to guide PCIs in 27% (15,613 of 57,845) of general and 27.5% (1,754 of 6,387) of ESRD patients. Among 4,759 eligible ESRD patients, 443 and 4,316 patients underwent OCT- and IVUS-guided PCIs, respectively. After matching, the incidence of the primary outcome was comparable between the OCT and IVUS groups (42.1 [95% CI: 36.2-48.0] vs 47.6 [95% CI: 43.0-52.2] events per 100 person-years; HR: 0.88; 95% CI: 0.74-1.06). The results were similar for all components of the primary outcome and in subgroup analyses.

Conclusions

The number of PCI- and IVI-guided procedures has progressively increased in the past decade in Taiwan in both the general and ESRD populations. Among ESRD patients on maintenance dialysis, the clinical outcomes were comparable between OCT- and IVUS-guided PCI.

Segmental post-percutaneous coronary intervention physiological gradients using ultrasonic or optical flow ratio: insights from ASET JAPAN study

Aims

Segmental pressure gradients post-percutaneous coronary intervention (PCI) can detect residual disease and optimization targets. Ultrasonic flow ratio (UFR) or optical flow ratio (OFR) offer simultaneous physiological and morphological assessment using a single imaging catheter. This study evaluated the utility of UFR and OFR in identifying residual disease post-PCI.

Methods and results

The study include patients from the Acetyl Salicylic Elimination Trial JAPAN Pilot study with complete intravascular imaging pullback data, where UFR or OFR was obtained post-PCI. Anatomical focal lesions distal and proximal to the stent were analysed in segments ≥5 mm long. UFR or OFR virtual pullback curves assessed intra-stent pressure gradients, defining physiological focal or diffuse by segmental pressure drops ≥0.05 over lengths <10 or ≥10 mm, respectively. The median post-PCI UFR/OFR was 0.93 (0.88-0.96) with 35.4% (69/195) vessels having a UFR/OFR < 0.91. There were significantly more focal lesions, both anatomical and physiological, proximal and distal to the stent in vessels with UFR/OFR < 0.91 compared with those ≥0.91. Agreement between anatomical and physiological focal lesions was moderate proximally (kappa = 0.553, P < 0.001) and fair distally (kappa = 0.219, P = 0.002). The in-stent gradient poorly predicted significant stent under-expansion. However, the virtual fractional flow reserve gradient performed well in detecting proximal or distal focal disease (area under the curve = 0.835 and 0.877, respectively).

Conclusion

UFR/OFR effectively identifies sub-optimal vessel physiology post-PCI and locates precise anatomical issues, validated by intravascular imaging.

Trial registration

The ASET JAPAN ClinicalTrials.gov reference: NCT05117866.

A novel radiomics-based technique for identifying vulnerable coronary plaques: a follow-up study

BACKGROUND

Previous reports have suggested that coronary computed tomography angiography (CCTA)-based radiomics analysis is a potentially helpful tool for assessing vulnerable plaques. We aimed to investigate whether coronary radiomic analysis of CCTA images could identify vulnerable plaques in patients with stable angina pectoris.

METHODS

This retrospective study included patients initially diagnosed with stable angina pectoris. Patients were randomly divided into either the training or test dataset at an 8 : 2 ratio. Radiomics features were extracted from CCTA images. Radiomics models for predicting vulnerable plaques were developed using the support vector machine (SVM) algorithm. The model performance was assessed using the area under the curve (AUC); the accuracy, sensitivity, and specificity were calculated to compare the diagnostic performance using the two cohorts.

RESULTS

A total of 158 patients were included in the analysis. The SVM radiomics model performed well in predicting vulnerable plaques, with AUC values of 0.977 and 0.875 for the training and test cohorts, respectively. With optimal cutoff values, the radiomics model showed accuracies of 0.91 and 0.882 in the training and test cohorts, respectively.

CONCLUSION

Although further larger population studies are necessary, this novel CCTA radiomics model may identify vulnerable plaques in patients with stable angina pectoris.

Utilization and Outcomes Associated With Intravascular Ultrasound During Abdominal and Thoracic Endovascular Aortic Interventions in the United States in the Contemporary Era (2016-2023)

BACKGROUND

Intravascular ultrasound (IVUS) use in aortic endovascular interventions, including thoracic endovascular aneurysm repair (TEVAR) and endovascular aneurysm repair (EVAR), may have similar benefits to those seen in coronary and peripheral interventions, but limited utilization and outcome data exist.

METHODS

Centers for Medicare and Medicaid Services claims data were used to identify patients undergoing TEVAR and EVAR from 2016 to 2023. Utilization trends were stratified by region, urbanicity, distressed communities index, community versus academic center, Medicare versus dual enrollment status, indication, urgency, and presence of dissection with malperfusion. Inverse probability weighting was used to assess the impact of IVUS on a composite outcome of repeat aortic intervention or death. Cox regression was used to estimate weighted hazard ratios.

RESULTS

A total of 136 540 patients underwent TEVAR and EVAR, of which 9.8% (13 364) used IVUS. IVUS use increased slightly from 2016 to 2023, driven more by use in TEVAR compared with EVAR, and was higher in academic settings, with Medicare and Medicaid dual enrollment, in the West, with dissections, with malperfusion and for elective procedures. IVUS was associated with a lower risk of the primary outcome at 30-days (hazard ratio, 0.80 [95% CI, 0.73-0.89]; P<0.001) and 6-months (hazard ratio, 0.93 [95% CI, 0.87-0.99]; P=0.022) for all-comers. Subgroup analysis suggested lower risks of the primary outcome with IVUS use for aneurysm driven by the abdominal segment, malperfusion, thoracoabdominal dissection with malperfusion, thoracoabdominal repair, and chronic kidney disease.

CONCLUSIONS

IVUS use has increased slightly in TEVAR and EVAR with heterogeneity in use. IVUS implementation during TEVAR and EVAR was associated with improved early and mid-term outcomes, particularly in certain subsets.

Prospective investigation of calcium score in optical coherence tomography-guided revascularization to identify lesions with low risk for stent under expansion: the CORAL study

The optical coherence tomography (OCT)-based calcium scoring system was developed to guide optimal lesion preparation strategies for percutaneous coronary intervention (PCI) of calcified lesions. However, the score was derived retrospectively, and a prospective investigation is lacking. The CORAL (UMIN000053266) study was a single-arm, prospective, multicenter study that included patients with calcified lesions with OCT-calcium score of 1-2 to investigate whether these lesions could be optimally treated with a balloon-only preparation strategy using a non-compliant/scoring/cutting balloon. The primary endpoint was strategy success (successful stent placement with a final percent diameter stenosis [%DS] < 20% and Thrombolysis In Myocardial Infarction flow grade III without crossover to rotational atherectomy/orbital atherectomy/intravascular lithotripsy [RA/OA/IVL]). A superiority analysis for the primary endpoint was performed by comparing the study cohort with a performance goal of 83.3%. One hundred and eighteen patients with 130 lesions were enrolled. The mean age was 79.0 ± 10.3 years, and 79 patients (66.9%) were male. The OCT-calcium score was 1 for 81 lesions (62.3%) and 2 for 49 lesions (37.7%). The %DS improved from 47.0 ± 14.8% preprocedure to 11.1 ± 5.6% postprocedure. Stent expansion ≥ 70% was achieved in 90.2%. The strategy success rate was 93.1% (95% confidence interval: 87.3-96.8), and superiority against the performance goal was achieved without any crossover to RA/OA/IVL (P = 0.0027). The OCT-calcium score could identify mild/moderately calcified lesions treatable by PCI with the balloon-first strategy using a non-compliant/scoring/cutting balloon for predilatation, with a high strategy success rate. These results support the intravascular imaging-based treatment algorithm for calcified lesions proposed by CVIT.

Panvascular concept in the evaluation and treatment of intracranial atherosclerotic stenosis

Cerebrovascular disease is the leading causes of death and disability worldwide. Intracranial atherosclerotic stenosis (ICAS) is one of the major causes of ischemic stroke, especially in the Asian population. It is urgent to explore effective screening methods for early diagnosis to improve prognosis of patients with ICAS. Recently, the concept of panvascular medicine has provided a direction for the exploration of evaluation of ICAS. Based on the concept of "panvascular medicine," atherosclerosis is the common pathological feature of panvascular disease, such as ICAS and coronary artery disease (CAD). In-depth research on the formation and development of plaques, the development and application of more precise preoperative assessment and detection methods, and the utilization of new interventional equipment have greatly enhanced the precision of diagnosis and treatment of CAD. Studies attempt to apply similar evaluation and treatment in ICAS. The deeper understanding, the more accurate diagnosis and treatment, contributing to improve the prognosis of patients with ICAS. This review focuses on these evaluations and treatment of CAD applied in the field of ICAS.

Management of Stent Underexpansion and Aorto-ostial Lesions

Stent underexpansion (SU) and aorto-ostial lesions (AOL) are challenging conditions commonly faced during clinical practice in the setting of percutaneous coronary interventions. Compared to other interventional settings, both SU and AOL are associated with an increased risk of immediate and late events following percutaneous coronary intervention. Several specific strategies including the systematic use of intracoronary imaging and dedicated techniques for lesions' preparation and calcium debulking have been described. This narrative review summarises the currently available options for the diagnosis and treatment of both SU and AOL, highlighting the potential benefits and limits of each technique in these specific settings.

Cost-effectiveness of intravascular ultrasound-guided percutaneous intervention in patients with acute coronary syndromes: a UK perspective

BACKGROUND

Use of intravascular ultrasound (IVUS) during percutaneous coronary intervention (PCI) is associated with improved clinical outcomes over angiography alone. Despite this, the adoption of IVUS in clinical practice remains low.

AIMS

To examine the cost-effectiveness of IVUS-guided PCI compared to angiography alone in patients with acute coronary syndromes (ACS).

METHODS AND RESULTS

A 1-year decision tree and lifetime Markov model were constructed to compare the cost-effectiveness of IVUS-guided PCI to angiography alone for two hypothetical adult populations consisting of 1000 individuals: ST-elevation myocardial infarction (STEMI) and unstable angina/non-ST-elevation myocardial infarction (UA/NSTEMI) patients undergoing drug-eluting stent (DES) implantation. The United Kingdom (UK) healthcare system perspective was applied using 2019/20 costs. All-cause death, myocardial infarction (MI), repeat PCI, lifetime costs, life expectancy, and quality-adjusted life-years (QALYs) were assessed. Over a lifetime horizon, IVUS-guided PCI was cost-effective compared to angiography alone in both populations, yielding an incremental cost-effectiveness ratio of £3649 and £5706 per-patient in STEMI and UA/NSTEMI patients, respectively.In the 1-year time horizon, the model suggested that IVUS was associated with reductions in mortality, MI, and repeat PCI by 51%, 33%, and 52% in STEMI and by 50%, 29%, and 57% in UA/NSTEMI patients, respectively. Sensitivity analyses demonstrated the robustness of the model with IVUS being 100% cost-effective at a willingness to pay threshold of £20 000 per QALY-gained.

CONCLUSIONS

From a UK healthcare perspective, an IVUS-guided PCI strategy was highly cost-effective over angiography alone amongst ACS patients undergoing DES implantation due to the medium- and long-term reduction in repeat PCI, death, and MI.

Superiority of photon-counting computed tomography for detecting high-risk unstable angina patients: two case reports

Coronary artery disease is the leading cause of death among non-communicable diseases. The management strategy prioritizes early detection and optimal treatment, with emerging roles for imaging approaches. Photon-counting computed tomography is a new non-invasive diagnostic imaging tool that can detect high-risk plaques in coronary artery disease patients. Using photon-counting computed tomography in screening and intravascular ultrasound later in verifying diagnosis and intervention guidance could be a new technique to swiftly discover unstable plaques, prepare lesions for surgery, and determine the optimal percutaneous intervention strategy. However, there is no documentation available for this new approach. We reported two acute coronary syndromes managed with a combination of two imaging methods. Despite receiving medical therapy, the first case continued to experience chest pain, leading to the detection of plaque ulceration in the left anterior descending artery. On the other hand, two PCCT screenings within 6 months revealed plaque progression in the second case. We then used IVUS to confirm the lesions and proceed to intervention. We successfully discharged both cases, and they showed no symptoms 6 months after discharge.

Prognostic impact of intravascular imaging in percutaneous coronary intervention according to atherothrombotic risk: a post hoc analysis of a randomized clinical trial

INTRODUCTION AND OBJECTIVES

Recent randomized controlled trials support the use of intravascular imaging-guided percutaneous coronary intervention (PCI) to improve patient prognosis. However, the subsequent risk of clinical events in patients with coronary artery disease is not determined solely by lesion characteristics or how these lesions are treated. The current study investigated whether the effects of intravascular imaging in complex PCI vary according to atherothrombotic risks.

METHODS

This study was a post hoc analysis of the RENOVATE-COMPLEX-PCI trial, which compared intravascular imaging-guided PCI with angiography-guided PCI in patients with complex coronary artery lesions. The study population was stratified by atherothrombotic risk, assessed using the Thrombolysis in Myocardial Infarction risk score for secondary prevention (TRS-2P). TRS-2P is calculated based on the presence of the following factors: age ≥ 75 years, diabetes mellitus, hypertension, smoking, peripheral arterial disease, stroke, coronary artery bypass grafting, heart failure, and renal dysfunction. Patients were categorized into low-risk (TRS-2P <3) or high-risk (TRS-2P ≥ 3) groups. The primary endpoint was target vessel failure, a composite of cardiac death, target vessel-related myocardial infarction, or clinically driven target vessel revascularization.

RESULTS

Among the total study population, 1247 patients were categorized as low-risk, and 392 as high-risk. The risk of target vessel failure was significantly higher in the high-risk group than in the low-risk group (15.5% vs 7.2%; HR, 2.13; 95%CI, 1.51-3.00; P <.001). The benefits of intravascular imaging-guided PCI over angiography-guided PCI did not differ between the low-risk group (5.6% vs 10.4%; HR, 0.56; 95%CI, 0.36-0.86) and the high-risk group (14.1% vs 18.5%; HR, 0.71; 95%CI, 0.41-1.24), with no significant interaction (interaction P=.496).

CONCLUSIONS

In this hypothesis-generating post hoc analysis of the RENOVATE-COMPLEX-PCI trial, patients with high atherothrombotic risk had significantly worse clinical outcomes than those with low atherothrombotic risk. Nevertheless, the prognostic impact of intravascular imaging-guided PCI compared with angiography-guided PCI was similarly observed in both low- and high-risk groups. RENOVATE-COMPLEX-PCI clinical trial register number: NCT03381872.

Quantitative Coronary Angiography Guidance for Drug-Eluting Stent Implantation: A Narrative Review

Background

Percutaneous coronary intervention (PCI) using drug-eluting stents is an established strategy for the treatment of significant obstructive coronary artery disease. Evidence supports that intravascular imaging-guided PCI offers advantages over conventional angiography-guided PCI, though its use is limited, likely due to high costs. Angiography-guided PCI relies on visual estimation, leading to inter- and intra-observer variability and suboptimal outcomes. Quantitative coronary angiography (QCA) provides reliable information about vascular dimensions, overcoming these limitations. Poststenting postdilation with appropriately sized noncompliant balloons improves outcomes by increasing lumen area and reducing stent malapposition.

Aims

We investigated the procedural details of each modality used to guide PCI and assessed the utility of QCA-guided PCI with routine postdilation when intravascular imaging is unavailable.

Methods and Results

A systematic search was conducted from inception to May 31, 2024, identifying nine randomized controlled trials (with over 500 patients) that compared outcomes of PCI guided by intravascular imaging versus conventional angiography or QCA. The findings indicate that intravascular imaging guidance significantly improves clinical outcomes compared to angiography guidance. Notably, QCA-guided PCI with routine postdilation yielded outcomes comparable to those achieved with intravascular imaging-guided PCI.

Conclusions

QCA-guided PCI with routine postdilation may be a viable alternative for improving PCI outcomes, especially in settings where intravascular imaging is unavailable.

Recent Advances in the Treatment of Coronary In-Stent Restenosis

In-stent restenosis (ISR) remains the predominant cause of stent failure and the most common indication for repeat revascularization. Despite technological advances in stent design, ISR continues to pose significant challenges, contributing to increased morbidity and mortality among patients undergoing percutaneous coronary interventions. In the last decade, intravascular imaging has emerged as an important method for identifying the mechanisms behind ISR and guiding its treatment. Treatment options for ISR have expanded to include balloon angioplasty, cutting or scoring balloons, intravascular lithotripsy, atheroablative devices, drug-eluting stents, drug-coated balloons, surgical revascularization, and intravascular brachytherapy. The aim of the current review is to describe the classification and mechanisms of ISR, provide a comprehensive and updated overview of the evidence supporting different treatment strategies, suggest a management algorithm, and present insights into future developments in the field.

CatLet score and clinical CatLet score as predictors of long-term outcomes in patients with acute myocardial infarction presenting later than 12 hours from symptom onset

BACKGROUND

Our recently developed Coronary Artery Tree description and Lesion EvaluaTion (CatLet) angiographic scoring system is unique in its description of the variability in the coronary anatomy, the degree of stenosis of a diseased coronary artery, and its subtended myocardial territory, and can be utilized to predict clinical outcomes for patients with acute myocardial infarction (AMI) presenting ≤12 h after symptom onset. The current study aimed to assess whether the Clinical CatLet score (CCS), as compared with CatLet score (CS), better predicted clinical outcomes for AMI patients presenting >12 h after symptom onset.

METHODS

CS was calculated in 1018 consecutive AMI patients enrolled in a retrospective registry. CCS was calculated by multiplying CS by the ACEF I score (age, creatinine, and left ventricular ejection fraction). Primary endpoint was major adverse cardiac events (MACEs) at 4-year-follow-up, a composite of cardiac death, myocardial infarction, and ischemia-driven revascularization.

RESULTS

Over a 4-year follow-up period, both scores were independent predictors of clinical outcomes after adjustment for a broad spectrum of risk factors. Areas-under-the-curve (AUCs) for CS and CCS were 0.72(0.68-0.75) and 0.75(0.71-0.78) for MACEs; 0.68(0.63-0.73) and 0.78(0.74-0.83) for all-cause death; 0.73(0.68-0.79) and 0.83(0.79-0.88) for cardiac death; and 0.69(0.64-0.73) and 0.75(0.7-0.79) for myocardial infarction; and 0.66(0.61-0.7) and 0.63(0.58-0.68) for revascularization, respectively. CCS performed better than CS in terms of the above-mentioned outcome predictions, as confirmed by the net reclassification and integrated discrimination indices.

CONCLUSIONS

CCS was better than CS to be able to risk-stratify long-term outcomes in AMI patients presenting >12 h after symptom onset. These findings have indicated that both anatomic and clinical variables should be considered in decision-making on management of patients with AMI presenting later.

Long-term Follow-up Optical Coherence Tomography Assessment of Primary Percutaneous Coronary Intervention for Unprotected Left Main

Background

Elective unprotected left main (ULM) percutaneous coronary intervention (PCI) has long-term mortality rates comparable to surgical revascularization, thanks to advances in drug-eluting stent (DES) design, improved PCI techniques, and frequent use of intravascular imaging. However, urgent PCI of ULM culprit lesions remains associated with high in-hospital mortality and unfavourable long-term outcomes, including DES restenosis and stent thrombosis (ST). This analysis aimed to examine the long-term outcomes and healing of DES implanted in ULM during primary PCI using high-resolution optical coherence tomography (OCT) imaging.

Methods

A total of 15 consecutive patients undergoing long-term OCT follow-up of ULM primary PCI from a high-volume center were included in this analysis. During the index primary PCI all subjects underwent angio-guided DES implantation, and follow-up was uneventful in all but one subject who had a non-target PCI lesion. The primary endpoint was the percentage of covered, uncovered, and malappossed stent struts at long-term follow-up. Secondary endpoints included quantitative and qualitative OCT measurements. For the left main bifurcation, a separate analysis was performed for three different segments: left main (LM), polygon of confluence (POC) and distal main branch (dMB), in all cases.

Results

The average follow-up interval until OCT was 1580 ± 1260 days. Despite aorto-ostial stent protrusions in 40% of patients, optimal image quality was achieved in 93.3% of cases. There were higher rates of malapposed (11.4 ± 16.6 vs. 13.1 ± 8.3 vs. 0.3 ± 0.5%; p < 0.001) and lower rates of covered struts (81.7 ± 16.8 vs. 83.7 ± 9.2 vs. 92.4 ± 6.8%; p = 0.041) observed for the LM and POC segment compared to the dMB. Significantly malapposed stent struts (>400 μm) were less likely to be covered at follow-up, than struts with a measured strut to vessel wall distance of <400 μm (15.4 ± 21.6 vs. 24.8 ± 23.9%; p = 0.011). Neoatherosclerosis was observed in 5 (33.3%) and restenotic neointimal hyperplasia (NIH) in 2 (13.3%) patients, requiring PCI in 33.3% of patients.

Conclusions

Long-term OCT examination of DES implanted during primary PCI for culprit ULM lesions demonstrated high rates of incomplete strut coverage, late malapposition, and high subclinical DES failure rates. These negative OCT results highlight the need for image optimization strategies during primary PCI to improve DES-related long-term outcomes.

Impact of Stenting Long Lesions on Clinical Outcomes in Patients Presenting With Acute Coronary Syndrome and Multivessel Disease: Data From the BIOVASC Trial

An increased total stent length (TSL) might be associated with a higher risk of clinical events; however, in patients with multivessel disease (MVD), a considerable TSL is often required. In patients presenting with acute coronary syndrome and MVD, immediate complete revascularization was associated with shorter TSL in the BIOVASC (Immediate versus staged complete revascularisation in patients presenting with acute coronary syndrome and multivessel coronary disease) Trial. This is a subanalysis of the BIOVASC trial comparing clinical outcomes in patients with either <60 or ≥60 mm TSL. The primary outcome was a composite of all-cause mortality, myocardial infarction, any unplanned ischemia driven revascularization, or cerebrovascular events at 2 years after the index procedure. A total of 1,525 patients were enrolled in the BIOVASC trial, of whom 855 had a TSL of ≥60 mm (long TSL). No significant difference was established when comparing patients treated with either long or short TSL in terms of the primary outcome at 2-year follow-up, which occurred in 117 patients (13.7%) in the ≥60 mm group and 69 patients (10.3%) in the <60 mm group (adjusted hazard ratio 1.25, 95% confidence interval 0.92 to 1.69, p = 0.16). Furthermore, no significant differences were observed in the secondary end points. In conclusion, in patients with acute coronary syndrome and MVD, long stenting did not show a significant difference in clinical event rate compared with short stenting.

Unlocking the Secrets of Acute Coronary Syndromes Using Intravascular Imaging: From Pathophysiology to Improving Outcomes

Acute coronary syndrome (ACS) represents the most severe manifestation of coronary artery disease. Intravascular imaging, both intravascular ultrasound (IVUS) and optical coherence tomography (OCT), have played crucial roles for the impressive reduction in mortality of ACS. Intravascular imaging is useful for the detection of atherosclerotic mechanism (plaque rupture, calcified nodules, or plaque erosions) and for the evaluation of nonatherosclerotic and nonobstructive types of ACS. In addition, IVUS and OCT play a crucial role in the optimization of the PCI. The aim of the current review is to present the role of intravascular imaging in identifying the mechanisms of ACS and its prognostic role in future events, to review the current guidelines suggesting intravascular imaging use in ACS, to summarize its role in PCI in patients with ACS, and to compare IVUS and OCT.

Optical coherence tomography predictors of clinical outcomes after stent implantation: the ILUMIEN IV trial

BACKGROUND AND AIMS

Observational registries have suggested that optical coherence tomography (OCT) imaging-derived parameters may predict adverse events after drug-eluting stent (DES) implantation. The present analysis sought to determine the OCT predictors of clinical outcomes from the large-scale ILUMIEN IV trial.

METHODS

ILUMIEN IV was a prospective, single-blind trial of 2487 patients with diabetes or high-risk lesions randomized to OCT-guided versus angiography-guided DES implantation. All patients underwent final OCT imaging (blinded in the angiography-guided arm). From more than 20 candidates, the independent OCT predictors of 2-year target lesion failure (TLF; the primary endpoint), cardiac death or target-vessel myocardial infarction (TV-MI), ischaemia-driven target lesion revascularization (ID-TLR), and stent thrombosis were analysed by multivariable Cox proportional hazard regression in single treated lesions.

RESULTS

A total of 2128 patients had a single treated lesion with core laboratory-analysed final OCT. The 2-year Kaplan-Meier rates of TLF, cardiac death or TV-MI, ID-TLR, and stent thrombosis were 6.3% (n = 130), 3.3% (n = 68), 4.3% (n = 87), and 0.9% (n = 18), respectively. The independent predictors of 2-year TLF were a smaller minimal stent area (per 1 mm2 increase: hazard ratio 0.76, 95% confidence interval 0.68-0.89, P < .0001) and proximal edge dissection (hazard ratio 1.77, 95% confidence interval 1.20-2.62, P = .004). The independent predictors of cardiac death or TV-MI were smaller minimal stent area and longer stent length; of ID-TLR were smaller intra-stent flow area and proximal edge dissection; and of stent thrombosis was smaller minimal stent expansion.

CONCLUSIONS

In the ILUMIEN IV trial, the most important OCT-derived post-DES predictors of both safety and effectiveness outcomes were parameters related to stent area, expansion and flow, proximal edge dissection, and stent length.

Safety and Feasibility of Robot-Assisted Percutaneous Coronary Intervention Using the AVIAR 2.0 System: A Prospective, Multi-Center, Single-Arm, Open, Investigator-Initiated, Post-Approval Clinical Trial

BACKGROUND AND OBJECTIVES

Traditional manual percutaneous coronary intervention (PCI) exposes operators to significant radiation and physical stress. The recently developed Advanced Vascular Intervention Assist Robot (AVIAR) 2.0 system in South Korea aimed to overcome these issues by evaluating its safety and feasibility in a clinical setting.

METHODS

The study enrolled patients with stable angina from 2 medical centers. Single-vessel de novo lesions were treated using the AVIAR 2.0 system. The primary endpoints were technical success (using the AVIAR system for PCI devices, including guidewires, balloon catheters, and stents, without switching to manual) and clinical success (<30% residual stenosis in the treated lesion and no major cardiovascular events within 48 hours or before discharge). Secondary endpoints included operator radiation exposure and procedural time. Safety was assessed using treatment-emergent adverse events.

RESULTS

Twenty patients (mean age, 63.9±8.5 years, 70% male) underwent robot-assisted PCI for lesions mainly in the left anterior descending artery and right coronary artery, with 95% (19/20) classified as B2/C lesions. The average robotic procedural time was 23:06±05:55 minutes. Technical success was 100%, with no need for manual conversion. Clinical success was 100%, with no major complications until discharge. Operator effective radiation dose was reduced by 84% compared to table effective doses.

CONCLUSIONS

The AVIAR 2.0 system appears to be a safe and effective adjunct to manual PCI, enhancing procedural efficiency and reducing operator radiation exposure. These findings support the use of robotics in coronary interventions and suggest a promising future for minimally invasive cardiac procedures.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05981859.

Stent Underexpansion Is an Underestimated Cause of Intrastent Restenosis: Insights From RESTO Registry

BACKGROUND

Despite improvement in devices, in-stent restenosis remains a frequent and challenging complication of percutaneous coronary interventions.

METHODS AND RESULTS

The RESTO (Morphological Parameters of In-Stent Restenosis Assessed and Identified by OCT [Optical Coherence Tomography]; study NCT04268875) was a prospective multicenter registry including patients presenting with coronary syndromes related to in-stent restenosis. All patients underwent preintervention OCT analysis, which led to analysis of in-stent restenosis phenotype, number of strut layers, and presence of stent underexpansion. The primary end point was the in-stent restenosis type according to the OCT morphological classification. The 1-year incidence of target vessel failure (a composite of death from cardiac causes, target-vessel myocardial infarction, or ischemia-driven target-vessel revascularization) was assessed. The study included 297 patients. The culprit stent was a drug-eluting stent in 74.2% of cases. OCT analysis revealed the presence of neoatherosclerosis in 57% (52% calcified), neointimal hyperplasia in 43% (58% homogeneous), stent underexpansion (minimal stent area <4.5 mm2) in 43%, and multiple stent layers in 30%. The prepercutaneous coronary intervention OCT analysis modified the operator's strategy for management in 30% of cases. Treatment involved drug-eluting stent implantation in 61.6% and drug-eluting balloon angioplasty in 36.1% of cases with only 63.2% optimal results. The 1-year target vessel failure incidence was 11% (95% CI, 9%-13%). Residual postpercutaneous coronary intervention stent underexpansion was associated with significantly higher target vessel failure incidence (19% [95% CI, 14%-24%] versus 7% [95% CI, 5-9], P=0.01).

CONCLUSIONS

OCT identified neoatherosclerosis and neointimal hyperplasia in comparable proportions. Stent underexpansion was frequent and favored subsequent adverse clinical outcomes.

Clinical Significance of Optical Coherence Tomography-Guided Percutaneous Coronary Intervention for In-Stent Restenosis Within Drug-Eluting Stents: Impact on Patient Outcomes

BACKGROUND

The evidence for optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) in improving the prognosis of individuals with in-stent restenosis (ISR) is lacking.

METHODS AND RESULTS

This retrospective study enrolled 588 consecutive individuals with drug-eluting stent ISR undergoing PCI from March 2010 to March 2022. Two hundred seven (35.2%) underwent OCT guidance, and 381 (64.8%) underwent angiography guidance. Clinical outcomes were analyzed using survival curves. The primary clinical endpoint was 2-year major adverse cardiovascular events (MACEs), a composite of all-cause death, myocardial infarction, and target-vessel revascularization. Compared with angiography guidance, OCT guidance demonstrated a higher frequency of drug-coated balloon use and adjunctive therapeutic modalities, including predilation, postdilation, nonslip element balloons, and noncompliant balloons (P<0.05). Following PCI, the OCT-guided group achieved a significantly larger minimum lumen diameter (2.36 versus 2.15 mm, P<0.001) and a lower percentage diameter stenosis (17% versus 20%, P<0.001) than the angiography-guided group. Survival analysis revealed significantly lower 2-year MACEs in the OCT-guided group compared with the angiography-guided group (7% versus 15%, P=0.007), validated in the propensity matching analysis (7% versus 15%, P=0.001). Multiple sensitivity analyses showed that OCT-guided PCI treatment was an independent protective factor for 2-year MACEs in individuals with drug-eluting stent ISR.

CONCLUSIONS

Compared with angiography guidance, OCT guidance is associated with a lower 2-year MACE risk among individuals with drug-eluting stent ISR. Therefore, OCT should be actively considered for guiding PCI treatment in individuals with drug-eluting stent ISR.

REGISTRATION

Url: clinicaltrials.gov. Identifier: NCT03809754.

Intravascular Imaging in the Diagnosis and Management of Patients With Suspected Intracoronary Pathologies: A CJC White Paper

Intravascular imaging has become an integral part of the diagnostic and management strategies for intracoronary pathologies. In this White Paper we summarize current evidence and its implications on the use of intravascular imaging in interventional cardiology practice. The areas addressed are planning and optimization of percutaneous coronary intervention, management of stent failure, and evaluation of ambiguous coronary lesions and myocardial infarction with nonobstructive coronary disease. The findings presented followed the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system in an expert consensus process that involved a diverse writing group vetted by a review group. Expert consensus was achieved around 9 statements. Use of intravascular imaging in guiding percutaneous revascularization is supported by high-quality evidence, particularly for lesions with increased risk of recurrent events or stent failure. Specific considerations for intravascular imaging guidance of intervention in left main lesions, chronic occlusion lesions, and in patients at high risk of contrast nephropathy are explored. Use of intravascular imaging to identify pathologies associated with stent failure and guide repeat intervention, resolve ambiguities in lesion assessment, and establish diagnoses in patients who present with myocardial infarction with nonobstructive coronary disease is supported by moderate- to low-quality evidence. Each topic is accompanied by clinical pointers to aid the practicing interventional cardiologist in implementation of the White Paper findings. The findings presented in this White Paper will help to guide the use of intravascular imaging toward situations in which the balance of efficacy, safety, and cost are most optimal.

Impact of multiple ballooning on coronary lesions as assessed by optical coherence tomography and intravascular ultrasound

BACKGROUND

Optimal lesion preparation for coronary lesions has been reappraised in the interventional community, given the increasing use of drug-coated balloons for de novo lesions; however, whether multiple ballooning could achieve more favorable angiographic results compared with single ballooning remains unknown. We aimed to investigate the incremental effect of multiple ballooning on de novo coronary lesions over single ballooning as assessed by optical coherence tomography (OCT) and intravascular ultrasound (IVUS) among patients undergoing percutaneous coronary intervention (PCI).

METHODS

Patients with chronic coronary syndrome (CCS) undergoing PCI were enrolled. Ballooning before stent implantation was repeatedly performed for three times using the same semi-compliant balloon. OCT and IVUS were performed after each balloon dilatation. Primary outcome measure was the difference in the mean lumen area between post-1st ballooning (1B) and post-3rd ballooning (3B) as assessed by OCT.

RESULTS

A total of 32 lesions in 30 patients undergoing PCI between May 2021 and August 2022 were analyzed. Major plaque types of the lesions were fibrous (68.8%) and lipid (28.1%). Mean lumen area by OCT was significantly increased from 1B to 3B (5.9 ± 2.9 mm2 vs. 6.0 ± 2.9 mm2, difference: 0.2 ± 0.4 mm2, p = 0.040). There were significant increases from 1B to 3B in minimum lumen area by OCT (3.1 ± 1.5 mm2 vs. 3.6 ± 1.7 mm2, difference: 0.5 ± 0.6 mm2, p < 0.001) and mean dissection angle by OCT (65.6 ± 24.9° vs. 95.2 ± 34.0°, difference: 29.6 ± 25.5°, p < 0.001). Additionally, mean plaque area by IVUS was significantly decreased (8.0 ± 4.2 mm2 vs. 7.8 ± 4.1 mm2, difference: -0.2 ± 0.2 mm2, p < 0.001).

CONCLUSIONS

Among CCS patients with mainly non-calcified lesions, multiple ballooning significantly increased the lumen area and dissection angle compared with single ballooning.

Research frontiers and hotspots in optical coherence tomography applications among patients with acute coronary syndromes: Bibliometric and visual analysis

Research on the use of optical coherence tomography (OCT) in acute coronary syndrome (ACS) has increased in recent years. However, a comprehensive analysis of the trends and hotspots in OCT research is currently lacking. The objective of this study was to identify global trends in research on OCT in ACS from a bibliometric perspective and to provide researchers with new research hotspots. Relevant literature from 1998 to 2023 was retrieved from the Web of Science Core Collection. CiteSpace and VOSviewer software were used to collect and analyze publication trends in related fields. A total of 965 publications from 58 countries and 1389 institutions were included in the present study. We found that Japan produced the most publications (20.83%, 201), followed by the United States (19.90%, 192), and China (14.09%, 136). However, the United States has the highest total number of citations in this field. Harvard Medical School and Harbin Medical University had the highest numbers of publications and citations. The journal with the most publications was the International Journal of Cardiology. Plaque erosion, calcified nodules, and intracoronary imaging are the most recent research hotspots and frontiers. Our work summarizes 25 years of OCT research in the ACS, highlighting hotspots, key themes, and emerging frontiers to help guide future research.