IVUS-Guided Versus OCT-Guided Coronary Stent Implantation: A Critical Appraisal

Contemporary Trends and Outcomes of Intravascular Lithotripsy in Percutaneous Coronary Intervention: Insights From BMC2

BACKGROUND

With an aging population and an increase in the comorbidity burden of patients undergoing percutaneous coronary intervention (PCI), the management of coronary calcification for optimal PCI is critical in contemporary practice.

OBJECTIVES

This study sought to examine the trends and outcomes of coronary intravascular lithotripsy (IVL), rotational/orbital atherectomy, or both among patients who underwent PCI in Michigan.

METHODS

We included all PCIs between January 1, 2021, and June 30, 2022, performed at 48 Michigan hospitals. Outcomes included in-hospital major adverse cardiac events (MACEs) and procedural success.

RESULTS

IVL was used in 1,090 patients (2.57%), atherectomy was used in 1,743 (4.10%) patients, and both were used in 240 patients (0.57% of all PCIs). IVL use increased from 0.04% of PCI cases in January 2021 to 4.28% of cases in June 2022, ultimately exceeding the rate of atherectomy use. The rate of MACEs (4.3% vs 5.4%; P = 0.23) and procedural success (89.4% vs 89.1%; P = 0.88) were similar among patients treated with IVL compared with atherectomy, respectively. Only 15.6% of patients treated with IVL in contemporary practice were similar to the population enrolled in the pivotal IVL trials. Among such patients (n = 169), the rate of MACEs (0.0%) and procedural success (94.7%) were similar to the outcomes reported in the pivotal IVL trials.

CONCLUSIONS

Since its introduction in February 2021, coronary IVL use has steadily increased, exceeding atherectomy use in Michigan by February 2022. Contemporary use of IVL and atherectomy is generally associated with high rates of procedural success and low rates of complications.

Machine Learning Constructed Based on Patient Plaque and Clinical Features for Predicting Stent Malapposition: A Retrospective Study

BACKGROUND

Stent malapposition (SM) following percutaneous coronary intervention (PCI) for myocardial infarction continues to present significant clinical challenges. In recent years, machine learning (ML) models have demonstrated potential in disease risk stratification and predictive modeling.

HYPOTHESIS

ML models based on optical coherence tomography (OCT) imaging, laboratory tests, and clinical characteristics can predict the occurrence of SM.

METHODS

We studied 337 patients from the Affiliated Hospital of Zunyi Medical University, China, who had PCI and coronary OCT from May to October 2023. We employed nested cross-validation to partition patients into training and test sets. We developed five ML models: XGBoost, LR, RF, SVM, and NB based on calcification features. Performance was assessed using ROC curves. Lasso regression selected features from 46 clinical and 21 OCT imaging features, which were optimized with the five ML algorithms.

RESULTS

In the prediction model based on calcification features, the XGBoost model and SVM model exhibited higher AUC values. Lasso regression identified five key features from clinical and imaging data. After incorporating selected features into the model for optimization, the AUC values of all algorithmic models showed significant improvements. The XGBoost model demonstrated the highest calibration accuracy. SHAP values revealed that the top five ranked features influencing the XGBoost model were calcification length, age, coronary dissection, lipid angle, and troponin.

CONCLUSION

ML models developed using plaque imaging features and clinical characteristics can predict the occurrence of SM. ML models based on clinical and imaging features exhibited better performance.

Innovations in Intracoronary Imaging: Present Clinical Practices and Future Outlooks

Engaging intracoronary imaging (IC) techniques such as intravascular ultrasound or optical coherence tomography enables the precise description of vessel architecture. These imaging modalities have well-established roles in providing guidance and optimizing percutaneous coronary intervention (PCI) outcomes. Furthermore, IC is increasingly recognized for its diagnostic capabilities, as it has the unique capacity to reveal vessel wall characteristics that may not be apparent through angiography alone. This manuscript thoroughly reviews the contemporary landscape of IC in clinical practice. Focused on current methodologies, the review explores the utility and advancements in IC techniques. Emphasizing their role in clarifying coronary pathophysiology, guiding PCI, and optimizing patient outcomes, the manuscript critically evaluates the strengths and limitations of each modality. Additionally, the integration of IC into routine clinical workflows and its impact on decision-making processes are discussed. By synthesizing the latest evidence, this review provides valuable insights for clinicians, researchers, and healthcare professionals involved in the dynamic field of interventional cardiology.

Elucidating the Relationship between Neutrophil-Lymphocyte Ratio and Plaque Composition in Patients with Drug-Eluting Stent Restenosis by Virtual Histology-Intravascular Ultrasound

(1) Background: In-stent Restenosis (ISR) is a major factor influencing the prognosis and revascularization of target lesions. The plaque composition is unclear; therefore, it is critical to investigate ISR composition to identify clinical intervention markers. (2) Methods: This study was conducted on 36 patients with drug-eluting stent restenosis. The patients were classified into a Low Neutrophil-Lymphocyte Ratio (L-NLR) and High Neutrophil-Lymphocyte Ratio (H-NLR) according to the median NLR level of 36 patients. Discrepancies in the current information such as baseline data, biochemical examination, cardiac ultrasound data, etc., were examined to identify the underlying risk factors, and a multifactorial linear regression analysis of plaque properties was conducted. (3) Results: NLR = 2.64 was utilized to classify 18 patients into the L-NLR group and 18 patients into the H-NLR group. There were statistically significant differences in age, a pre-percutaneous coronary intervention (PCI) SYNTAX II score, a C-reactive protein (CRP), interleukin (IL)-6, plaque loading, a fibro-lipid tissue area, calcified nubs, and virtual histology-thin fibrous cap atherosclerotic (VH-TCFA). The significant impacts of variations in age, neutrophil-lymphocyte ratio (NLR) levels, and IL-6 levels on the plaque stress and percentage of the fibro-lipid tissue in virtual histology-intravascular ultrasound (VH-IVUS) were identified through multifactorial linear regression. (4) Conclusions: The high NLR group demonstrated increased myocardial injury severity, consistent with higher SYNTAX II scores, a higher plaque burden, and higher proportions of vulnerable components. NLR proved to be a risk factor for both the plaque load and the proportion of the fibro-lipid tissue in ISR.

Quantitative Coronary Angiography vs Intravascular Ultrasonography to Guide Drug-Eluting Stent Implantation: A Randomized Clinical Trial

Importance

Although intravascular ultrasonography (IVUS) guidance promotes favorable outcomes after percutaneous coronary intervention (PCI), many catheterization laboratories worldwide lack access.

Objective

To investigate whether systematic implementation of quantitative coronary angiography (QCA) to assist angiography-guided PCI could be an alternative strategy to IVUS guidance during stent implantation.

Design, Setting, and Participants

This randomized, open-label, noninferiority clinical trial enrolled adults (aged ≥18 years) with chronic or acute coronary syndrome and angiographically confirmed native coronary artery stenosis requiring PCI. Patients were enrolled in 6 cardiac centers in Korea from February 23, 2017, to August 23, 2021, and follow-up occurred through August 25, 2022. All principal analyses were performed according to the intention-to-treat principle.

Interventions

After successful guidewire crossing of the first target lesion, patients were randomized in a 1:1 ratio to receive either QCA- or IVUS-guided PCI.

Main Outcomes and Measures

The primary outcome was target lesion failure at 12 months, defined as a composite of cardiac death, target vessel myocardial infarction, or ischemia-driven target lesion revascularization. The trial was designed assuming an event rate of 8%, with the upper limit of the 1-sided 97.5% CI of the absolute difference in 12-month target lesion failure (QCA-guided PCI minus IVUS-guided PCI) to be less than 3.5 percentage points for noninferiority.

Results

The trial included 1528 patients who underwent PCI with QCA guidance (763; mean [SD] age, 64.1 [9.9] years; 574 males [75.2%]) or IVUS guidance (765; mean [SD] age, 64.6 [9.5] years; 622 males [81.3%]). The post-PCI mean (SD) minimum lumen diameter was similar between the QCA- and IVUS-guided PCI groups (2.57 [0.55] vs 2.60 [0.58] mm, P = .26). Target lesion failure at 12 months occurred in 29 of 763 patients (3.81%) in the QCA-guided PCI group and 29 of 765 patients (3.80%) in the IVUS-guided PCI group (absolute risk difference, 0.01 percentage points [95% CI, -1.91 to 1.93 percentage points]; hazard ratio, 1.00 [95% CI, 0.60-1.68]; P = .99). There was no difference in the rates of stent edge dissection (1.2% vs 0.7%, P = .25), coronary perforation (0.2% vs 0.4%, P = .41), or stent thrombosis (0.53% vs 0.66%, P = .74) between the QCA- and IVUS-guided PCI groups. The risk of the primary end point was consistent regardless of subgroup, with no significant interaction.

Conclusions and Relevance

Findings of this randomized clinical trial indicate that QCA and IVUS guidance during PCI showed similar rates of target lesion failure at 12 months. However, due to the lower-than-expected rates of target lesion failure in this trial, the findings should be interpreted with caution.

Trial Registration

ClinicalTrials.gov Identifier: NCT02978456.

Current Management of In-Stent Restenosis

In-stent restenosis (ISR) remains the primary cause of target lesion failure following percutaneous coronary intervention (PCI), resulting in 10-year incidences of target lesion revascularization at a rate of approximately 20%. The treatment of ISR is challenging due to its inherent propensity for recurrence and varying susceptibility to available strategies, influenced by a complex interplay between clinical and lesion-specific conditions. Given the multiple mechanisms contributing to the development of ISR, proper identification of the underlying substrate, especially by using intravascular imaging, becomes pivotal as it can indicate distinct therapeutic requirements. Among standalone treatments, drug-coated balloon (DCB) angioplasty and drug-eluting stent (DES) implantation have been the most effective. The main advantage of a DCB-based approach is the avoidance of an additional metallic layer, which may otherwise enhance neointimal hyperplasia, provide the substratum for developing neoatherosclerosis, and expose the patient to a persistently higher risk of coronary ischemic events. On the other hand, target vessel scaffolding by DES implantation confers relevant mechanical advantages over DCB angioplasty, generally resulting in larger luminal gain, while drug elution from the stent surface ensures the inhibition of neointimal hyperplasia. Nevertheless, repeat stenting with DES also implies an additional permanent metallic layer that may reiterate and promote the mechanisms leading to ISR. Against this background, the selection of either DCB or DES on a patient- and lesion-specific basis as well as the implementation of adjuvant treatments, including cutting/scoring balloons, intravascular lithotripsy, and rotational atherectomy, hold the potential to improve the effectiveness of ISR treatment over time. In this review, we comprehensively assessed the available evidence from randomized trials to define contemporary interventional treatment of ISR and provide insights for future directions.

Coronary Angiography, Intravascular Ultrasound, and Optical Coherence Tomography for Guiding of Percutaneous Coronary Intervention: A Systematic Review and Network Meta-Analysis

BACKGROUND

Results from multiple randomized clinical trials comparing outcomes after intravascular ultrasound (IVUS)- and optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) with invasive coronary angiography (ICA)-guided PCI as well as a pivotal trial comparing the 2 intravascular imaging (IVI) techniques have provided mixed results.

METHODS

Major electronic databases were searched to identify eligible trials evaluating at least 2 PCI guidance strategies among ICA, IVUS, and OCT. The 2 coprimary outcomes were target lesion revascularization and myocardial infarction. The secondary outcomes included ischemia-driven target lesion revascularization, target vessel myocardial infarction, death, cardiac death, target vessel revascularization, stent thrombosis, and major adverse cardiac events. Frequentist random-effects network meta-analyses were conducted. The results were replicated by Bayesian random-effects models. Pairwise meta-analyses of the direct components, multiple sensitivity analyses, and pairwise meta-analyses IVI versus ICA were supplemented.

RESULTS

The results from 24 randomized trials (15 489 patients: IVUS versus ICA, 46.4%, 7189 patients; OCT versus ICA, 32.1%, 4976 patients; OCT versus IVUS, 21.4%, 3324 patients) were included in the network meta-analyses. IVUS was associated with reduced target lesion revascularization compared with ICA (odds ratio [OR], 0.69 [95% CI, 0.54-0.87]), whereas no significant differences were observed between OCT and ICA (OR, 0.83 [95% CI, 0.63-1.09]) and OCT and IVUS (OR, 1.21 [95% CI, 0.88-1.66]). Myocardial infarction did not significantly differ between guidance strategies (IVUS versus ICA: OR, 0.91 [95% CI, 0.70-1.19]; OCT versus ICA: OR, 0.87 [95% CI, 0.68-1.11]; OCT versus IVUS: OR, 0.96 [95% CI, 0.69-1.33]). These results were consistent with the secondary outcomes of ischemia-driven target lesion revascularization, target vessel myocardial infarction, and target vessel revascularization, and sensitivity analyses generally did not reveal inconsistency. OCT was associated with a significant reduction of stent thrombosis compared with ICA (OR, 0.49 [95% CI, 0.26-0.92]) but only in the frequentist analysis. Similarly, the results in terms of survival between IVUS or OCT and ICA were uncertain across analyses. A total of 25 randomized trials (17 128 patients) were included in the pairwise meta-analyses IVI versus ICA where IVI guidance was associated with reduced target lesion revascularization, cardiac death, and stent thrombosis.

CONCLUSIONS

IVI-guided PCI was associated with a reduction in ischemia-driven target lesion revascularization compared with ICA-guided PCI, with the difference most evident for IVUS. In contrast, no significant differences in myocardial infarction were observed between guidance strategies.

Optimal lesion preparation before implantation of a Magmaris bioresorbable scaffold in patients with coronary artery stenosis: Rationale, design and methodology of the OPTIMIS study

Introduction

Percutaneous coronary intervention with implantation of a bioresorbable scaffold (BRS) provide the vessel support for a limited period allowing the vessel to restore normal vasomotion after degradation of the BRS, opposed to treatment with drug-eluting stents where the metal persist in the vessel wall. Late lumen loss and reduction in lumen area after implantation have been reported. The purpose of this study was to investigate whether intense pre-dilatation before BRS implantation resulted in less reduction of minimal lumen area at 6- and 12-month follow-up after implantation of a Magmaris BRS (MgBRS). Coronary imaging with optical coherence tomography (OCT) and intravascular ultrasound (IVUS) was assessed to track changes in lumen and vessel dimensions.

Methods

The prospective Optimal lesion PreparaTion before Implantation of the Magmaris bioresorbable scaffold In patients with coronary artery Stenosis (OPTIMIS) study randomly assigned eighty-two patients with chronic coronary syndrome to two pre-dilatation treatment strategies. Patients were randomized in a 1:1 ratio to pre-dilatation with either a non-compliant scoring balloon or a standard non-compliant balloon prior to implantation of a MgBRS. The treated segment was evaluated with OCT and IVUS at baseline, after 6 and 12 months to assess changes in lumen and vessel dimensions. The hypothesis was that more intense pre-dilatation with a non-compliant scoring balloon before MgBRS implantation can reduce the risk of late lumen reduction compared to standard pre-dilatation. The power calculation used expected MLA after 6 months (6.22 mm2 for the scoring balloon and 5.01 mm2 for the standard non-compliant balloon), power of 80 %, significance level of 0.05 and expected drop-out rate of 15 %, requiring 82 patients to be enrolled.

Results

Eighty-two patients were included in the study. Enrollment was from December 2020 to September 2023.

Conclusion

The hypothesis was that more intense pre-dilatation with a non-compliant scoring balloon before MgBRS implantation can reduce the risk of late lumen reduction compared to standard pre-dilatation.

Roadmap on the use of artificial intelligence for imaging of vulnerable atherosclerotic plaque in coronary arteries

Artificial intelligence (AI) is likely to revolutionize the way medical images are analysed and has the potential to improve the identification and analysis of vulnerable or high-risk atherosclerotic plaques in coronary arteries, leading to advances in the treatment of coronary artery disease. However, coronary plaque analysis is challenging owing to cardiac and respiratory motion, as well as the small size of cardiovascular structures. Moreover, the analysis of coronary imaging data is time-consuming, can be performed only by clinicians with dedicated cardiovascular imaging training, and is subject to considerable interreader and intrareader variability. AI has the potential to improve the assessment of images of vulnerable plaque in coronary arteries, but requires robust development, testing and validation. Combining human expertise with AI might facilitate the reliable and valid interpretation of images obtained using CT, MRI, PET, intravascular ultrasonography and optical coherence tomography. In this Roadmap, we review existing evidence on the application of AI to the imaging of vulnerable plaque in coronary arteries and provide consensus recommendations developed by an interdisciplinary group of experts on AI and non-invasive and invasive coronary imaging. We also outline future requirements of AI technology to address bias, uncertainty, explainability and generalizability, which are all essential for the acceptance of AI and its clinical utility in handling the anticipated growing volume of coronary imaging procedures.

Evaluation of the thickness of coronary calcium by 60-MHz intravascular ultrasound: head-to-head comparison with optical frequency domain imaging

The region behind the coronary calcium could not be visualized by intravascular ultrasound (IVUS) because of acoustic shadow. However, some pathological studies have shown that IVUS delineated the vessel border behind thin coronary calcium sheets. This study aimed to reveal whether recent IVUS can visualize the region behind thin coronary calcium sheets. Using 534 cross-sectional optical frequency domain images (OFDI), including severe calcified coronary lesions, calcium sheet thickness was measured by every 1°. Accordingly, the visibility of the vessel border behind the coronary calcium sheet was evaluated using 60-MHz IVUS images, which were longitudinally linked with OFDI ones. After carefully coordinating with the axial position, the association between the IVUS-derived permeability of the coronary calcium sheet and calcium thickness was evaluated. The maximum and mean calcium thickness by OFDI was 0.88 ± 0.39 and 0.62 ± 0.30 mm, respectively. By 60-MHz IVUS, 12.1% of the coronary calcium sheets had permeable segments. Comparing between OFDI and IVUS images, 48.6% of the coronary calcium sheets with maximum thickness ≤ 0.3 mm were sometimes permeable by 60-MHz IVUS, whereas most > 0.5 mm thick calcium sheets were impermeable. In the receiver operating characteristic curve analysis, the best cutoff values for the maximum and mean thickness of permeable calcium were 0.48 and 0.31 mm, respectively. Thus, 60-MHz IVUS can occasionally visualize the region behind a thin coronary calcium sheet. When using 60-MHz IVUS, this finding may be a predictive marker of calcium sheet with a thickness of < 0.5 mm.

Outcomes With Intravascular Ultrasound and Optical Coherence Tomography Guidance in Percutaneous Coronary Intervention

Intracoronary imaging has become an important tool in the treatment of complex lesions with percutaneous coronary intervention (PCI). This retrospective cohort study identified 1,118,475 patients with PCI from the Nationwide Readmissions Database from 2017 to 2019. Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) were identified with appropriate International Classification of Diseases, Tenth Revision codes. The primary outcome was major adverse cardiac events. The secondary outcomes include net adverse clinical events (NACEs), all-cause mortality, myocardial infarction (MI) readmission, admission for stroke, and emergency revascularization. The multivariate Cox proportional hazard regression was used to adjust for demographic and co-morbid confounders. Of 1,118,475 PCIs, 86,140 (7.7%) used IVUS guidance and 5,617 (0.5%) used OCT guidance. The median follow-up time was 184 days. The primary outcome of major adverse cardiac events was significantly lower for the IVUS (6.5% vs 7.6%; hazard ratio [HR] 0.89, 95% confidence interval [CI] 0.86 to 0.91, p <0.001) and OCT (4.4% vs 7.6%; HR 0.69, 95% CI 0.61 to 0.79, p <0.001) groups. IVUS was associated with significantly lower rates of NACEs (8.4% vs 9.4%; HR 0.92, 95% CI 0.89 to 0.94, p <0.001), all-cause mortality (3.5% vs 4.3%; HR 0.85, 95% CI 0.82 to 0.88, p <0.001), readmission for MI (2.7% vs 3.0%; HR 0.95, 95% CI 0.91 to 0.99, p = 0.012), and admission for stroke (0.5% vs 0.6%; HR 0.86, 95% CI 0.78 to 0.95, p = 0.002). OCT was associated with significantly lower rates of NACEs (6.6% vs 9.4%; HR 0.81, 95% CI 0.73 to 0.89, p <0.001) and all-cause mortality (1.8% vs 4.3%; HR 0.51, 95% CI 0.42 to 0.63, p <0.001). Emergency revascularization was not significantly different with IVUS guidance. Readmission for MI, stroke, and emergency revascularization were not significantly different with OCT guidance. A subgroup analysis of patients with ST-elevation MI and non-ST-elevation MI showed similar results. In conclusion, the use of IVUS and OCT guidance with PCI were associated with significantly lower rates of morbidity and mortality in real-world practice.

Optical Coherence Tomography-Guided or Intravascular Ultrasound-Guided Percutaneous Coronary Intervention: The OCTIVUS Randomized Clinical Trial

BACKGROUND

Intravascular imaging-guided percutaneous coronary intervention (PCI) with intravascular ultrasound (IVUS) or optical coherence tomography (OCT) showed superior clinical outcomes compared with angiography-guided PCI. However, the comparative effectiveness of OCT-guided and IVUS-guided PCI regarding clinical outcomes is unknown.

METHODS

In this prospective, multicenter, open-label, pragmatic trial, we randomly assigned 2008 patients with significant coronary artery lesions undergoing PCI in a 1:1 ratio to undergo either an OCT-guided or IVUS-guided PCI. The primary end point was a composite of death from cardiac causes, target vessel-related myocardial infarction, or ischemia-driven target-vessel revascularization at 1 year, which was powered for noninferiority of the OCT group compared with the IVUS group. Safety outcomes were also assessed.

RESULTS

At 1 year, primary end point events occurred in 25 of 1005 patients (Kaplan-Meier estimate, 2.5%) in the OCT group and in 31 of 1003 patients (Kaplan-Meier estimate, 3.1%) in the IVUS group (absolute difference, -0.6 percentage points; upper boundary of one-sided 97.5% CI, 0.97 percentage points; P<0.001 for noninferiority). The incidence of contrast-induced nephropathy was similar (14 patients [1.4%] in the OCT group versus 15 patients [1.5%] in the IVUS group; P=0.85). The incidence of major procedural complications was lower in the OCT group than in the IVUS group (22 [2.2%] versus 37 [3.7%]; P=0.047), although imaging procedure-related complications were not observed.

CONCLUSIONS

In patients with significant coronary artery lesions, OCT-guided PCI was noninferior to IVUS-guided PCI with respect to the incidence of a composite of death from cardiac causes, target vessel-related myocardial infarction, or ischemia-driven target-vessel revascularization at 1 year. The selected study population and lower-than-expected event rates should be considered in interpreting the trial.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique number: NCT03394079.

State-of-art review: intravascular imaging in percutaneous coronary interventions

The history of intravascular ultrasound (IVUS) and optical coherence tomography (OCT) reflects the relentless pursuit of innovation in interventional cardiology. These intravascular imaging technologies have played a pivotal role in our understanding of coronary atherosclerosis, vascular pathology, and the interaction of coronary stents with the vessel wall. Two decades of clinical investigations demonstrating the clinical efficacy and safety of intravascular imaging modalities have established these technologies as staples in the contemporary cardiac catheterization lab's toolbox and earning their place in revascularization clinical practice guidelines. In this comprehensive review, we will delve into the historical evolution, mechanisms, and technical aspects of IVUS and OCT. We will discuss the expanding evidence supporting their use in complex percutaneous coronary interventions, emphasizing their crucial roles in optimizing patient outcomes and ensuring procedural success. Furthermore, we will explore the substantial advances that have propelled these imaging modalities to the forefront of contemporary interventional cardiology. Finally, we will survey the latest developments in the field and explore the promising future directions that have the potential to further revolutionize coronary interventions.

Comparison of intravascular ultrasound, optical coherence tomography, and conventional angiography-guided percutaneous coronary interventions: A systematic review, network meta-analysis, and meta-regression

BACKGROUND

Intracoronary imaging modalities, including intravascular ultrasound (IVUS) and optical coherence tomography (OCT), provide valuable supplemental data unavailable on coronary angiography (CA) and have shown to improve clinical outcomes. We sought to compare the clinical efficacy of IVUS, OCT, and conventional CA-guided percutaneous coronary interventions (PCI).

METHODS

Frequentist and Bayesian network meta-analyses of randomized clinical trials were performed to compare clinical outcomes of PCI performed with IVUS, OCT, or CA alone.

RESULTS

A total of 28 trials comprising 12,895 patients were included. IVUS when compared with CA alone was associated with a significantly reduced risk of major adverse cardiovascular events (MACE) (risk ratio: [RR] 0.74, 95% confidence interval: [CI] 0.63-0.88), cardiac death (RR: 0.64, 95% CI: 0.43-0.94), target lesion revascularization (RR: 0.68, 95% CI: 0.57-0.80), and target vessel revascularization (RR: 0.64, 95% CI: 0.50-0.81). No differences in comparative clinical efficacy were found between IVUS and OCT. Rank probability analysis bestowed the highest probability to IVUS in ranking as the best imaging modality for all studied outcomes except for all-cause mortality.

CONCLUSION

Compared with CA, the use of IVUS in PCI guidance provides significant benefit in reducing MACE, cardiac death, and revascularization. OCT had similar outcomes to IVUS, but more dedicated studies are needed to confirm the superiority of OCT over CA.

Comparison of definitions of coronary artery reference sizes and effects on stent selection and evaluation of stent expansion

Accurate determination of coronary reference size is essential for optimal stent selection and evaluation of stent expansion during percutaneous coronary intervention (PCI). Several approaches for reference size estimation have been published with no universal agreement. The aim of this study was to investigate if potential differences in coronary reference size estimation lead to differences in stent and balloon selection and in detection of stent under expansion. Definitions for coronary reference size estimation, stent size selection, and stent expansion were identified in 17 randomized controlled trials. The identified methods were applied in a population of 32 clinical cases. Reference size estimates ranged up to 1.35mm, and indicated nominal stent size ranged up to 1.0 mm in the same case depending on method. Mean relative stent expansion ranged from 54±12% to mean 100±29% depending on the applied reference method. Choice of method for reference size estimation using intravascular imaging may influence stent selection and greatly affects evaluation of post-PCI stent expansion.

Accuracy of IVUS-Based Machine Learning Segmentation Assessment of Coronary Artery Dimensions and Balloon Sizing

Background

Accurate intravascular ultrasound (IVUS) measurements are important in IVUS-guided percutaneous coronary intervention optimization by choosing the appropriate device size and confirming stent expansion.

Objectives

The purpose of this study was to assess the accuracy of machine learning (ML) automatic segmentation of coronary artery vessel and lumen dimensions and balloon sizing.

Methods

Using expert analysis as the gold standard, ML segmentation of 60 MHz IVUS images was developed using 8,076 IVUS cross-sectional images from 234 patients, which were randomly split into training (83%) and validation (17%) data sets. The performance of ML segmentation was then evaluated using an independent test data set (437 images from 92 patients). The endpoints were the agreement rate between ML vs experts' measurements for appropriate balloon size selection, and lumen and acute stent areas. Appropriate balloon size was determined by rounding down from the mean vessel diameter or rounding up from the mean lumen diameter to the next balloon size. The difference of lumen area ≥0.5 mm2 was considered as clinically significant.

Results

ML model segmentation correlated well with experts' segmentation for training data set with a correlation coefficient of 0.992 and 0.993 for lumen and vessel areas, respectively. The agreement rate in lumen and acute stent areas was 85.5% and 97.0%, respectively. The agreement rate for appropriate balloon size selection was 70.6% by vessel diameter only and 92.4% by adding lumen diameter.

Conclusions

ML model IVUS segmentation measurements were well-correlated with those of experts and selected an appropriate balloon size in more than 90% of images.

Comparison of Long-Term Outcomes Between Intravascular Ultrasound-, Optical Coherence Tomography- and Angiography-Guided Stent Implantation: A Meta-Analysis

Intravascular ultrasonography (IVUS) and optical coherence tomography (OCT) guided percutaneous coronary interventions (PCI) are alternative techniques to angiography-guided (ANG-g) PCI in patients with coronary artery disease (CAD), especially for optimal stent deployment in coronary arteries. We conducted a network meta-analysis including studies comparing those three techniques. We searched databases for studies that compared IVUS, OCT, and ANG-g PCI in patients with CAD. Overall, 52 studies with 231,137 patients were included in this meta-analysis. ANG-g PCI had higher major adverse cardiovascular events (MACEs), all-cause death, cardiac death, myocardial infarction (MI), target lesion revascularization (TLR), and stent thrombosis (ST) than IVUS-guided PCI. Of note, both OCT-guided and IVUS-guided PCI had similar outcomes. The frequency of MACEs, cardiac death, and MI were higher in ANG-g PCI than in OCT-guided PCI. The highest benefit was established with OCT for MACEs (P-score=.973), MI (P-score=.823), and cardiac death (P-score=.921) and with IVUS for all-cause death (P-score=.792), TLR (P -score=.865), and ST (P-score=.930). This network meta-analysis indicated that using OCT or IVUS for optimal stent implantation provides better outcomes in comparison with ANG-g in patients with CAD undergoing PCI.

Outcomes of Intravascular Ultrasound-Guided Percutaneous Coronary Intervention in Non-ST-Elevation Myocardial Infarction-Propensity Matched Regression Analysis

Intravascular ultrasound (IVUS) guided percutaneous coronary intervention (PCI) is indicated in complex interventions. There is a paucity of evidence for outcomes with large studies on using IVUS during PCI in non-ST-elevation myocardial infarction (NSTEMI). Our objective was to compare the in-hospital outcome of IVUS-guided with that of nonguided PCI among NSTEMI hospitalizations. The National Inpatient Sample (2016 to 2019) was queried to identify all hospitalizations with a principal diagnosis of NSTEMI. In our study, we compared outcomes of PCI with and without IVUS guidance using a multivariate logistic regression model after propensity score matching, with the primary outcome being in-hospital mortality. A total of 671,280 NSTEMI-related hospitalizations were identified, of whom 48,285 (7.2%) underwent IVUS-guided PCI compared with 622,995 (92.8%) who underwent non-IVUS PCI. After adjusted analysis on matched pairs, we found that IVUS-guided PCI had a lower risk of in-hospital mortality than that of non-IVUS PCI (adjusted odds ratio [aOR] 0.736, confidence interval (CI) 0.578 to 0.937, p = 0.013). However, there was a higher use of mechanical circulatory support in the IVUS-guided PCI (aOR 2.138, CI 1.84 to 2.47, p <0.001) than in non-IVUS PCI. The odds of cardiogenic shock (aOR 1.11, CI 0.93 to 1.32, p = 0.233) and procedural complications (aOR 0.794, CI 0.549 to 1.14, p = 0.22) were similar between the cohorts. Hence, we conclude that patients with NSTEMIs who underwent IVUS-guided PCI had less risk of in-hospital mortality and a greater requirement of mechanical circulatory support than did those who underwent non-IVUS PCI, with no difference in procedural complications. Large prospective trials are essential to validate these findings.

SCAI Expert Consensus Statement on Management of In-Stent Restenosis and Stent Thrombosis

Stent failure remains the major drawback to the use of coronary stents as a revascularization strategy. Recent advances in imaging have substantially improved our understanding of the mechanisms underlying these occurrences, which have in common numerous clinical risk factors and mechanical elements at the time of stent implantation. In-stent restenosis remains a common clinical problem despite numerous improvements in-stent design and polymer coatings over the past 2 decades. It generates significant health care cost and is associated with an increased risk of death and rehospitalization. Stent thrombosis causes abrupt closure of the stented artery and therefore carries a high risk of myocardial infarction and death. This Society for Cardiovascular Angiography & Interventions (SCAI) Expert Consensus Statement suggests updated practical algorithmic approaches to in-stent restenosis and stent thrombosis. A pragmatic outline of assessment and management of patients presenting with stent failure is presented. A new SCAI classification that is time-sensitive with mechanistic implications of in-stent restenosis is proposed. Emphasis is placed on frequent use of intracoronary imaging and assessment of timing to determine the precise etiology because that information is crucial to guide selection of the best treatment option. SCAI recommends image-guided coronary stenting at the time of initial implantation to minimize the occurrence of stent failure. When in-stent restenosis and stent thrombosis are encountered, imaging should be strongly considered to optimize the subsequent approach.

Drug-Coated Balloon in Primary Percutaneous Coronary Intervention

According to the latest coronary interventional guidelines, a drug-eluting stent is the recommended reperfusion therapy in primary percutaneous coronary intervention (pPCI). However, deficiencies and defects, such as in-stent restenosis (ISR), incomplete stent apposition, stent thrombosis, reinfarction after stent implantation, long-term dual antiplatelet drug use, and adverse reactions of metal implants, plague clinicians and patients. Drug-coated balloon (DCB), which delivers antiproliferative agents into the vessel wall without stent implantation and leaves no implants behind after the procedure, is a novel option for percutaneous coronary intervention and has proven to be a promising strategy in cases of ISR, small vessel coronary artery disease, and bifurcation lesions. However, most of the available experience has been gained in elective percutaneous coronary intervention, and experience in pPCI is lacking. The current evidence for the use of DCB-only in pPCI was discussed and analyzed in this review.

Multimodality OCT, IVUS and FFR evaluation of coronary intermediate grade lesions in women vs. men

Background

The pathophysiology of atherosclerotic plaque formation and its vulnerability seem to differ between genders due to contrasting risk profiles and sex hormones, however this process is still insufficiently understood. The aim of the study was to compare the differences between sexes regarding the optical coherence tomography (OCT), intravascular ultrasound (IVUS) and fractional flow reserve (FFR)-derived coronary plaque indices.

Methods

In this single-center multimodality imaging study patients with intermediate grade coronary stenoses identified in coronary angiogram (CAG) were evaluated using OCT, IVUS and FFR. Stenoses were considered significant when the FFR value was ≤0.8. Minimal lumen area (MLA), was analyzed by OCT in addition to plaque stratification into fibrotic, calcific, lipidic and thin-cap fibroatheroma (TCFA). IVUS was used for evaluation of lumen-, plaque- and vessel volume, as well as plaque burden.

Results

A total of 112 patients (88 men and 24 women) with chronic coronary syndromes (CCS), who underwent CAG were enrolled. No significant differences in baseline characteristics were present between the study groups. The mean FFR was 0.76 (0.73-0.86) in women and 0.78 ± 0.12 in men (p = 0.695). OCT evaluation showed a higher prevalence of calcific plaques among women than men p = 0.002 whereas lipid plaques were more frequent in men (p = 0.04). No significant differences regarding minimal lumen diameter and minimal lumen area were found between the sexes. In IVUS analysis women presented with significantly smaller vessel area, plaque area, plaque volume, vessel volume (11.1 ± 3.3 mm² vs. 15.0 ± 4.6 mm² p = 0.001, 6.04 ± 1.7 mm² vs. 9.24 ± 2.89 mm² p < 0.001, 59.8 ± 35.2 mm³ vs. 96.3 (52.5-159.1) mm³ p = 0.005, 106.9 ± 59.8 mm³ vs. 153.3 (103-253.4) mm³ p = 0.015 respectively). At MLA site plaque burden was significantly greater for men than women (61.50 ± 7.7% vs. 55.5 ± 8.0% p = 0.005). Survival did not differ significantly between women and men (94.6 ± 41.9 months and 103.51 ± 36.7 months respectively; p = 0.187).

Conclusion

The presented study did not demonstrate significant differences in FFR values between women and men, yet a higher prevalence of calcific plaques by OCT and lower plaque burden at the MLA site by IVUS was found in women vs. men.

Intravascular Imaging versus Physiological Assessment versus Biomechanics-Which Is a Better Guide for Coronary Revascularization

Today, coronary artery disease (CAD) continues to be a prominent cause of death worldwide. A reliable assessment of coronary stenosis represents a prerequisite for the appropriate management of CAD. Nevertheless, there are still major challenges pertaining to some limitations of current imaging and functional diagnostic modalities. The present review summarizes the current data on invasive functional and intracoronary imaging assessment using optical coherence tomography (OCT), and intravascular ultrasound (IVUS). Amongst the functional parameters-on top of fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR)-we point to novel angiography-based measures such as quantitative flow ratio (QFR), vessel fractional flow reserve (vFFR), angiography-derived fractional flow reserve (FFRangio), and computed tomography-derived flow fractional reserve (FFR-CT), as well as hybrid approaches focusing on optical flow ratio (OFR), computational fluid dynamics and attempts to quantify the forces exaggerated by blood on the coronary plaque and vessel wall.

Current Role of Intracoronary Imaging for Implementing Risk Stratification and Tailoring Culprit Lesion Treatment: A Narrative Review

Our understanding of the pathophysiology of acute coronary syndrome and of the vascular biology of coronary atherosclerosis has made enormous progress with the implementation of intravascular imaging. Intravascular imaging contributes to overcoming the known limitations of coronary angiography and allows for the in vivo discrimination of plaque morphology giving insight into the underlying pathology of the disease process. The possibility of using intracoronary imaging to characterize lesion morphologies and correlate them with clinical presentations may influence the treatment of patients and improve risk stratification, offering the opportunity for tailored management. This review examines the current role of intravascular imaging and describes how intracoronary imaging represents a valuable tool for modern interventional cardiology in order to improve diagnostic accuracy and offer a tailored approach to the treatment of patients with coronary artery disease, especially in the acute setting.

Intravascular Ultrasound-Guided Percutaneous Coronary Intervention: Evidence and Clinical Trials

The intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) that was associated with improved post-procedural outcomes and long-term clinical outcomes has shown benefits not only in patients with complex lesions but also with simplex lesions. However, the use of IVUS during PCI remains low; therefore, further prospective, randomized, controlled trials are required to strengthen the recommendations and consequently expand its usage. The aim of this review is to discuss the previous evidences and clinical trials regarding IVUS-guided PCI and to discover the necessity for future studies to broaden its use in the real-world clinical practice.

Optical coherence tomography factors for adverse events in patients with severe coronary calcification

BACKGROUND

Severe coronary calcification is a factor for worse outcomes after percutaneous coronary intervention.

AIMS

To identify factors of pre- and post-stent optical coherence tomography (OCT) for device-oriented clinical endpoints (DoCE) in patients with severely calcified lesions requiring drug-eluting stent (DES) implantation.

METHODS

A total of 237 consecutive patients with stable coronary disease who underwent OCT imaging of severe coronary lesions were included. Lesions with a maximum calcium angle >180°, maximum calcium thickness > 0.5 mm, and calcium length > 5 mm were defined as having severe calcification.

RESULTS

The prevalence of eruptive calcified nodules (41% vs. 18%, p = 0.002) and medial dissection with calcified flaps (59% vs. 26%, p < 0.001) was significantly higher in patients with DoCE (n = 34) than those without DoCE (n = 203). Multivariate analyses demonstrated that the presence of a medial dissection with calcified flap within the DES-implanted segment was independently associated with a higher incidence of DoCE (odds ratio, 3.367; 95% confidence interval, 1.503-7.543; p = 0.003). The combined presence of eruptive calcified nodules and medial dissection with calcified flaps was associated with a higher incidence of DoCE (p < 0.001) during a median of 756 days after DES implantation.

CONCLUSIONS

OCT-defined severely calcified lesions with eruptive calcified nodules and medial dissection with calcified flaps were associated with a higher incidence of DoCE after DES implantation.

Advances in Intravascular Ultrasound

Since its inception, intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have played a significant role in evaluating the pathophysiology of coronary artery disease (CAD) guiding the interventional and medical management of CAD improving outcomes in patients. Although the benefits of each of these modalities have been proven, due to some limitations, no single intravascular imaging technique has been proven to provide a detailed and complete evaluation of all CAD lesions. The use of different intravascular imaging modalities sequentially may lead to complications, which are cumbersome, consume time, and add financial burden to the patient. Recently, hybrid imaging catheters that combine OCT and IVUS benefits have been developed to limit these problems. Intravascular imaging techniques we are using currently have some drawbacks that hinder accurate assessment of plaque morphology and pathobiology as demonstrated in many histological studies, causing difficulty in identifying high-risk plaques. To overcome these limitations, great efforts have been put into developing hybrid, dual-probe catheters by combining imaging modalities to get an accurate analysis of plaque characteristics, and high-risk lesions. At present, many dual-probe catheters are available including combined IVUS-OCT, near-infrared spectroscopy-IVUS that is available commercially, the OCT-near infrared fluorescence (NIRF) molecular imaging, IVUS-NIRF, and combined fluorescence lifetime-IVUS imaging. Application of this combined multimodal imaging in clinical practice overcomes the limitations of standalone imaging and helps in providing a comprehensive and accurate visualization of plaque characteristics, composition, and plaque biology. The present article summarizes the advances in hybrid intravascular imaging, analyses the technical hindrances that should be known to have a use in the different clinical circumstances, and the till date shreds of evidence available from their first clinical application aiming to bring these modalities into the limelight and their potential role in the study of CAD.

Role of plaque imaging for identification of vulnerable patients beyond the stage of myocardial ischemia

Chronic coronary syndrome (CCS) is a progressive disease, which often first manifests as acute coronary syndrome (ACS). Imaging modalities are clinically useful in making decisions about the management of patients with CCS. Accumulating evidence has demonstrated that myocardial ischemia is a surrogate marker for CCS management; however, its ability to predict cardiovascular death or nonfatal myocardial infarction is limited. Herein, we present a review that highlights the latest knowledge available on coronary syndromes and discuss the role and limitations of imaging modalities in the diagnosis and management of patients with coronary artery disease. This review covers the essential aspects of the role of imaging in assessing myocardial ischemia and coronary plaque burden and composition. Furthermore, recent clinical trials on lipid-lowering and anti-inflammatory therapies have been discussed. Additionally, it provides a comprehensive overview of intracoronary and noninvasive cardiovascular imaging modalities and an understanding of ACS and CCS, with a focus on histopathology and pathophysiology.

Intravascular imaging modalities in coronary intervention: Insights from 3D-printed phantom coronary models

INTRODUCTION AND OBJECTIVES

Several studies comparing optical coherence tomography (OCT) and intravascular ultrasound (IVUS) have revealed that OCT consistently provides smaller area and diameter measurements. However, comparative assessment in clinical practice is difficult. Three-dimensional (3D) printing offers a unique opportunity to assess intravascular imaging modalities. We aim to compare intravascular imaging modalities using a 3D-printed coronary artery in a realistic simulator and to assess whether OCT underestimates intravascular dimensions, exploring potential corrections.

METHODS

A standard realistic left main anatomy with an ostial left anterior descending artery lesion was replicated using 3D printing. After provisional stenting and optimization, IVI was obtained. Modalities included 20 MHz digital IVUS, 60 MHz rotational IVUS (HD-IVUS) and OCT. We assessed luminal area and diameters at standard locations.

RESULTS

Considering all coregistered measurements, OCT significantly underestimated area, minimal diameter and maximal diameter measurements in comparison to IVUS and HD-IVUS (p<0.001). No significant differences were found between IVUS and HD-IVUS. A significant systematic dimensional error was found in OCT auto-calibration by comparing known reference diameter of guiding catheter (1.8 mm) to measured mean diameter (1.68 mm±0.04 mm). By applying a correction factor based on the reference guiding catheter area to OCT, the luminal areas and diameters became not significantly different compared to IVUS and HD-IVUS.

CONCLUSION

Our findings suggest that automatic spectral calibration method for OCT is inaccurate, with a systematic underestimation of luminal dimensions. When guiding catheter correction is applied the performance of OCT is significantly improved. These results may be clinically relevant and need to be validated.

Preliminary study of the significance of reverberation by IVUS detection for patients with severe calcified lesions

To explore the potential significance of the reverberation of calcification by comparing both intravascular ultrasound (IVUS) and optical coherence tomography (OCT) measurement post manual coregistration. The reverberation phenomenon is often detected by IVUS for severe calcified lesions post rotational atherectomy (RA), which is thought to be due to the glassy and smooth inner surfaces of calcifications. Because of the poor penetration of IVUS, it is impossible to measure the thickness of calcifications, and the relationship between multiple reverberations and the thickness of calcification lesions has not been reported before. A total of forty-nine patients with severe calcified coronary lesions that were detected by IVUS and OCT simultaneously were enrolled in our retrospective study. If reverberation phenomena were detected by IVUS, intravascular imaging (IVI) data (including distance between the IVUS catheter center and the inner surface of the reverberation signal, the intervals between all adjacent reverberation signals, the number of layers of reverberation in IVUS, and the thickness of the calcification in OCT) were measured at the same position and same direction (each cross-section had 4 mutually perpendicular directions) at 1-mm intervals. The correlation between each reverberation observational value and OCT data was the primary target in this retrospective study, and the correlation between reverberation and calcium crack post predilatation was analyzed in other 15 patients. Four hundred twenty-eight valid observational points were analyzed simultaneously by IVUS and OCT; among them, 300 points had a single layer of reverberation, 83 had double layers of reverberation and 42 had multiple layers (≥ 3 layers) of reverberation by IVUS detection post-RA. Multivariate logistic regression analysis showed that the number of layers of reverberation by IVUS was significantly related to the thickness of calcifications by OCT at the same point and in the same direction (p < 0.001). Single, double, and multiple layers of reverberation in IVUS correspond to median calcification thicknesses (interquartile ranges (IQRs)) of 0.620 mm (0.520-0.720), 0.950 mm (0.840-1.040) and 1.185 mm (1.068-1.373), respectively, by OCT detection. Another 100 points in other 15 patients with integrated IVUS data pre- and post-predilatation showed that only single layer of reverberation was related to calcium crack (p < 0.001). The number of layers of reverberation signal detected by IVUS is positively correlated with the thickness of calcifications measured by OCT post-RA and single layer of reverberation is correlated to calcium crack post-predilatation.

Assessment of fractional flow reserve in intermediate coronary stenosis using optical coherence tomography-based machine learning

Objectives

This study aimed to evaluate and compare the diagnostic accuracy of machine learning (ML)- fractional flow reserve (FFR) based on optical coherence tomography (OCT) with wire-based FFR irrespective of the coronary territory.

Background

ML techniques for assessing hemodynamics features including FFR in coronary artery disease have been developed based on various imaging modalities. However, there is no study using OCT-based ML models for all coronary artery territories.

Methods

OCT and FFR data were obtained for 356 individual coronary lesions in 130 patients. The training and testing groups were divided in a ratio of 4:1. The ML-FFR was derived for the testing group and compared with the wire-based FFR in terms of the diagnosis of ischemia (FFR ≤ 0.80).

Results

The mean age of the subjects was 62.6 years. The numbers of the left anterior descending, left circumflex, and right coronary arteries were 130 (36.5%), 110 (30.9%), and 116 (32.6%), respectively. Using seven major features, the ML-FFR showed strong correlation (r = 0.8782, P < 0.001) with the wire-based FFR. The ML-FFR predicted wire-based FFR ≤ 0.80 in the test set with sensitivity of 98.3%, specificity of 61.5%, and overall accuracy of 91.7% (area under the curve: 0.948). External validation showed good correlation (r = 0.7884, P < 0.001) and accuracy of 83.2% (area under the curve: 0.912).

Conclusion

OCT-based ML-FFR showed good diagnostic performance in predicting FFR irrespective of the coronary territory. Because the study was a small-size study, the results should be warranted the performance in further large-scale research.

Diagnostic efficacy of the optical flow ratio in patients with coronary heart disease: A meta-analysis

BACKGROUND

Coronary atherosclerotic heart disease (CAD) remains one of the most serious diseases threatening human health and life. PCI (Percutaneous Coronary Intervention) is the most common treatment for patients with CAD. A rigorous and comprehensive assessment of coronary artery lesions is now needed before PCI, however, there is no consensus on how best evaluate the combination of various intracavitary imaging techniques. By merging the benefits of physiological assessment and high-definition imaging, the optical flow ratio (OFR) has emerged as a novel technology with promising prospects for application.

METHODS

A systematic review of the literature was conducted. Studies that met the criteria of the meta-analysis were considered to assess OFR and FFR (fractional flow reserve). And the summary values of sensitivity and specificity of diagnostic tests and summary receiver operating curves (SROC) were calculated.

RESULTS

A total of 5 studies were included. The sensitivity and specificity of OFR in the diagnosis of coronary artery lesions were 0.83 (95% CI: 0.75-0.88) and 0.94 (95% CI: 0.91-0.96), respectively; the positive likelihood ratio and the negative likelihood ratio were 14 (95% CI: 9.3, 21.3) and 0.18 (95% CI:0.13, 0.27), respectively. OFR showed good correlation and consistency with FFR.

CONCLUSION

The new OFR technique achieve an encouraging diagnostic performance, which also showed good correlation and consistency with FFR.

Malnutrition leads to the progression of coronary artery calcification in hemodialysis patients

BACKGROUND

Malnutrition is considered a risk factor for cardiovascular disease in patients with chronic kidney disease. However, no in vivo studies have reported on using optical coherence tomography to evaluate the effect of nutritional status on coronary atherosclerosis in hemodialysis patients. We aimed to conduct a detailed analysis of the effect of nutritional status on the coronary arteries in hemodialysis patients.

METHODS

Among 64 hemodialysis patients who underwent percutaneous coronary interventions, 41 that underwent optical coherence tomography imaging were included in this study. And, among them, 24 patients that could also be evaluated using OCT also at the 6-month follow-up were included in this study. The patients were divided into two groups based on nutritional evaluation using the geriatric nutritional risk index. Culprit and non-culprit lesions were evaluated at baseline and after 6 months.

RESULTS

In the culprit lesions at baseline, the length of the lipid plaque was significantly smaller in the malnutrition group. In contrast, the thickness and length of the calcified plaque and the angle of the calcified nodule were significantly larger (each p < 0.01). In the non-culprit lesions, the 6-month change in the angle of the calcified plaque was significantly greater in the malnutrition group (p = 0.02). The significant factors that affected the change in the angle of calcification were "malnutrition at geriatric nutritional risk index" [odds ratio, 8.17; 95% confidence interval, 1.79 to 37.33; p < 0.01] and "serum phosphorus level" (odds ratio, 3.73; 95% confidence interval, 1.42 to 9.81; p < 0.01).

CONCLUSIONS

Appropriate management of nutritional status is crucial for suppressing the progression of coronary artery disease in hemodialysis patients.

Very Short Versus Longer Dual Antiplatelet Treatment After Coronary Interventions: A Systematic Review and Meta-analysis

BACKGROUND

Very short (≤ 3 months) duration of dual antiplatelet therapy (VSDAPT) has recently been proposed after percutaneous coronary intervention (PCI) with drug-eluting stent (DES).

OBJECTIVES

The aim of this systematic review and meta-analysis was to compare very short versus > 3 months' duration of dual antiplatelet treatment (DAPT) in patients undergoing PCI with DES, focusing on ischemic and bleeding events.

METHODS

Three major databases (Medline, Cochrane Central Register of Controlled Trials, and Scopus) were screened for eligible randomized controlled trials (RCTs). The primary endpoint of our meta-analysis was the incidence of net adverse clinical events (NACE), as defined per trial, while secondary endpoints were major adverse cardiovascular events (MACE), all-cause and cardiovascular mortality, myocardial infarction, stroke, stent thrombosis, repeat revascularization, and major bleeding.

RESULTS

We included eight RCTs with a total of 41,204 patients; 20,592 patients were allocated to VSDAPT and the remaining 20,612 patients were randomized to a longer DAPT period. The abbreviated regimen significantly reduced NACE (odds ratio [OR] 0.83, 95% confidence interval [Cl] 0.74-0.95) and major bleeding (OR 0.71, 95% Cl 0.61-0.82), without affecting mortality or ischemic events (stroke, myocardial infarction, revascularization, and stent thrombosis).

CONCLUSIONS

VSDAPT significantly decreased the odds of NACEs and major bleeding by 17% and 29%, respectively, without increasing ischemic events. Thus, VSDAPT could be well tolerated and feasible after PCI with DES.

CLINICAL TRIALS REGISTRATION

Open Science Framework (10.17605/OSF.IO/4H2JB) Very short-term DAPT significantly reduces NACE and major bleedings, without affecting mortality and ischemic events (MACE, MI, stroke, stent thrombosis and revascularization). CI confidence intervals, DAPT dual antiplatelet therapy, DES drug-eluting stents, MACE major adverse cardiovascular events, MI myocardial infarction, NACE net adverse clinical events, OR odds ratio, PCI percutaneous coronary interventions.

Drug-Eluting Stent Restenosis: Modern Approach to a Classic Challenge

In-stent restenosis (ISR) is a recognized complication following percutaneous coronary intervention in which the luminal diameter is narrowed through neointimal hyperplasia and vessel remodeling. Although rates of ISR have decreased in most recent years owing to newer generation drug-eluting stents, thinner struts, and better intravascular imaging modalities, ISR remains a prevalent dilemma that proves to be challenging to manage. Several factors have been proposed to contribute to ISR formation, including mechanical stent characteristics, technical factors during the coronary intervention, and biological aspects of drug-eluting stents. Presentation of ISR can range from asymptomatic to late myocardial infarction and could be difficult to differentiate from acute thrombus formation. No definite guidelines are present on the management of ISR. In this review, we will discuss the mechanisms underlying ISR and provide insight into patient-related and procedural risk factors contributing to ISR, in addition to highlighting common treatment approaches utilized in the management of ISR.

Intravascular molecular imaging: translating pathophysiology of atherosclerosis into human disease conditions

Progression of atherosclerotic plaque in coronary arteries is characterized by complex cellular and non-cellular molecular interactions. Within recent years, atherosclerosis has been recognized as inflammation-driven disease condition, where progressive stages are characterized by morphological changes in plaque composition but also relevant molecular processes resulting in increased plaque vulnerability. While existing intravascular imaging modalities are able to resolve key morphological features during plaque progression, they lack capability to characterize the molecular profile of advanced atherosclerotic plaque. Because hybrid imaging modalities may provide incremental information related to plaque biology, they are expected to provide synergistic effects in detecting high risk patients and lesions. The aim of this article is to review existing literature on intravascular molecular imaging approaches, and to provide clinically oriented proposals of their application. In addition, we assembled an overview of future developments in this field geared towards detection of patients at risk for cardiovascular events.

Intracoronary Imaging of Vulnerable Plaque-From Clinical Research to Everyday Practice

The introduction into clinical practice of intravascular imaging, including intravascular ultrasound (IVUS), optical coherence tomography (OCT) and their derivatives, allowed for the in vivo assessment of coronary atherosclerosis in humans, including insights into plaque evolution and progression process. Intravascular ultrasound, the most commonly used intravascular modality in many countries, due to its low resolution cannot assess many features of vulnerable plaque such as lipid plaque or thin-cap fibroatheroma. Thus, novel methods were introduced to facilitate this problem including virtual histology intravascular ultrasound and later on near-infrared spectroscopy and OCT. Howbeit, none of the currently used modalities can assess all known characteristics of plaque vulnerability; hence, the idea of combining different intravascular imaging methods has emerged including NIRS-IVUS or OCT-IVUS imaging. All of those described methods may allow us to identify the most vulnerable plaques, which are prone to cause acute coronary syndrome, and thus they may allow us to introduce proper treatment before plaque destabilization.

Complex, high-risk percutaneous coronary intervention types, trends, and in-hospital outcomes among different age groups: An insight from a national registry

BACKGROUND

Complex, high-risk percutaneous coronary intervention (PCI) (CHiP) is increasingly being undertaken in octogenarians. However, limited data exist on CHiP types, trends, and outcomes in the octogenarian.

METHODS

This is a retrospective cohort study from a national registry dataset on CHiP undertaken in patients with stable angina in England and Wales (January 2006 and December 2017) according to three age groups (group 1 [G1]: &lt; 65 years; group 2 [G2]: 65-79 years; and group 3 [G3]: ≥80 years).

RESULTS

Of 424,290 elective PCI procedures, 138,831 (33.0%) were CHiP [G1: 46,832 (33.7%); G2: 59,544 (42.9%); G3: 32,455 (23.4%)]. Among CHiP types, chronic total occlusion (CTO) (49.2%), prior coronary artery bypass graft (CABG) (30.4%), and severe vascular calcification (21.8%) were common in G1; prior CABG (42.9%), CTO (32.9%), and severe vascular calcifications (27%) were common in G2; prior CABG (15.8%), severe vascular calcification (15.5%), and chronic renal failure (11.1%) were common CHiP among the octogenarians. The older age groups had higher adjusted odds (aOR) for adverse outcomes [G2: mortality, aOR 1.7, 95% confidence interval (CI): (1.3-2.3); major bleeding, aOR 1.3, 95% CI (1.1-1.5); MACCE, aOR 1.2, 95% CI (1.0-1.3); G3: mortality, aOR 2.6, 95%CI (1.9-3.6); major bleeding, aOR 1.4, 95% CI (1.1-1.7); MACCE, aOR 1.3, 95% CI (1.1-1.5)].

CONCLUSION

There were significant differences in the types of CHiP cases undertaken and clinical outcomes across age groups.

Network Meta-analysis of Trials Comparing Intravascular Ultrasound, Optical Coherence Tomography, and Angiography-Guided Technique for Drug-Eluting Stent Implantation

Background

The current advances in coronary imaging with the introduction of intravascular ultrasound (IVUS), and more recently, optical coherence tomography (OCT) have overcome the limitations of coronary angiography.

Objective

This study aimed to conduct a comprehensive network meta-analysis of randomized clinical trials to report clinical outcomes among patients undergoing drug-eluting stent (DES) implantation either by IVUS- or OCT-guided technique or angiography alone.

Methods

PubMed/MEDLINE and EMBASE databases were searched systematically for all relevant published randomized clinical trials from the inception of the respective database to October 15th, 2021. The outcomes of interest assessed in this meta-analysis were major adverse cardiac events, myocardial infarction, target vessel revascularization, all-cause mortality, and cardiovascular mortality. All the endpoints were expressed as odds ratio (OR) with 95% CI. The network diagrams were computed using the OR as an effective measure. All statistical analyses were carried out in R statistical software version 4.0.3.

Results

A total of 14 randomized clinical trials were included in our meta-analysis. In patient undergoing DES implantation, angiography alone was associated with higher odds of major adverse cardiac events (OR, 1.62; 95% CI, 1.17-2.24), target vessel revascularization (OR, 1.60; 95% CI, 1.21-2.13) and cardiovascular mortality (OR, 1.97; 95% CI, 1.25-3.11). However, OCT demonstrated similar odds of major adverse cardiac events, cardiovascular mortality, and target vessel revascularization compared with IVUS. The odds of myocardial infarction and all-cause mortality were similar among all the 3 groups.

Conclusions

Although angiography alone was associated with worse outcomes than IVUS in a patient undergoing DES implantation, no difference in outcome was noted between patients undergoing DES implantation with OCT compared with IVUS. Advanced intracoronary imaging use should be encouraged to prevent excess mortality and morbidity.

Contemporary Management of Severely Calcified Coronary Lesions

Coronary artery calcification is increasingly prevalent in our patient population. It significantly limits the procedural success of percutaneous coronary intervention and is associated with a higher risk of adverse cardiovascular events both in the short-term and long-term. There are several modalities for modifying calcified plaque, such as balloon angioplasty (including specialty balloons), coronary atheroablative therapy (rotational, orbital, and laser atherectomy), and intravascular lithotripsy. We discuss each modality’s relative advantages and disadvantages and the data supporting their use. This review also highlights the importance of intravascular imaging to characterize coronary calcification and presents an algorithm to tailor the calcium modification therapy based on specific coronary lesion characteristics.

Intravascular imaging in coronary stent restenosis: Prevention, characterization, and management

Despite the introduction of drug-eluting stents to combat the neointimal hyperplasia that occurred after BMS implantation, in-stent restenosis is still encountered in a significant number of patients, particularly as increasingly complex lesions are tackled by percutaneous coronary intervention. Many biological and mechanical factors interplay to produce restenosis, some of which are avoidable. Intravascular imaging provided unique insights into various forms of stent-related mechanical issues that contribute to this phenomenon. From a practical perspective, intravascular imaging can therefore help to optimize the stenting procedure to avert these issues. Moreover, once the problem of restenosis eventuates, imaging can guide the management by tackling the underlying identified mechanism. Finally, it can be used to evaluate the re-intervention results. Nevertheless, with the emergence of different treatment options, more evidence is needed to define patient/lesion-specific characteristics that may help to tailor treatment selection in a way that improves clinical outcomes.